JP2007093338A - Visual inspection system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a visual inspection system for inspecting anomalous parts in the outer circumferential surfaces of objects to be inspected such as a cylindrical tube and capable of simplifying a system constitution, accurately inspecting the anomalous parts, and easily handing the objects to be inspected, in other words, easily inserting and extracting the objects to be inspected. <P>SOLUTION: The visual inspection system for inspecting anomalous parts in the outer circumferential surfaces of objects W2 to be inspected in the form of a cylindrical tube, a cylindrical column, a semi-cylindrical tube, and a semi-cylindrical column, comprises a pair of semi-cylindrical or half-ring illumination means 210 arranged on both ends of an object to be inspected; an imaging means 220 at a prescribed height on the center of the object to be inspected in its longitudinal direction; and a mechanism for rotating the object to be inspected in the form of a cylindrical tube or a cylindrical column. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an appearance inspection apparatus for detecting scratches, cracks, and the like on the outer peripheral surface of a cylindrical, columnar, substantially semi-cylindrical, or substantially semi-cylindrical object based on an appearance image captured by an imaging unit such as a camera. It is about.

  As a device for inspecting the appearance of the outer peripheral surface of an article, two ring-shaped light sources that irradiate light of different colors from different directions to the article passing through or on the inner side, and direct to the rod-shaped inspection object A color image pickup unit that is arranged in the optical axis direction and picks up a portion irradiated with light from the two ring-shaped light sources, and an image from the color image pickup unit is separated into images of each color, and the separated colors A calculation unit that obtains a difference from the image of the image, then takes the absolute value of the difference image to obtain a difference absolute value image, binarizes the difference absolute value image, and detects the presence or absence of the uneven defect from the binarized image; There is known an appearance inspection apparatus including the above (for example, see Patent Document 1).

  Also, as shown in FIG. 4, square plane illumination 410 is installed at both ends of the inspection object W4, and abnormal portions such as scratches and cracks are illuminated in white, and the image is taken by an imaging means 420 such as a camera. Therefore, an appearance inspection apparatus 400 that inspects abnormal places is also known.

JP-A-2005-37203

  However, in the appearance inspection apparatus using the ring-shaped light source as described above, there is no space for installing a mechanism for supplying or discharging the object to be inspected between the pair of ring-shaped light sources. In addition to complexity, the image processing method has become complicated.

  Further, in the appearance inspection apparatus using the above-described square planar illumination, brightness unevenness occurs on the surface of the object to be inspected, and it is distinguished whether it is brightly shining due to abnormal places or brightly shining due to uneven brightness. There was a problem that it was difficult to attach and accurate visual inspection could not be performed.

  Accordingly, an object of the present invention is to simplify the apparatus configuration and accurately inspect an abnormal part in an appearance inspection apparatus that inspects an abnormal part such as a scratch or a crack on an outer peripheral surface of an inspection object such as a cylindrical body. In addition, an object of the present invention is to provide an appearance inspection apparatus that can handle an object to be inspected, that is, can be easily taken in and out.

  The invention according to claim 1 is an appearance inspection apparatus that inspects scratches and cracks on the outer peripheral surface of a cylindrical, columnar, substantially semi-cylindrical, or substantially semi-cylindrical object, and is arranged at both ends of the object. The above-mentioned problem is solved by having a pair of illumination means having a semicircular shape or a semi-ring shape and having an imaging means at a predetermined height on the longitudinal center of the inspection object.

  According to a second aspect of the invention, in addition to the configuration of the first aspect of the invention, the inspection object is rotated in order to detect scratches and cracks in the outer peripheral portion of the cylindrical and columnar inspection objects. The above-described problem is further solved by adopting a configuration having a mechanism for causing the problem to occur.

  The cylindrical, columnar, substantially semi-cylindrical, and substantially semi-cylindrical objects to be inspected by the present invention are not particularly limited, but for pins and bushes that are parts of the chain. And is preferably applied.

  According to the appearance inspection apparatus of the first aspect, it is an appearance inspection apparatus that inspects abnormal portions such as scratches and cracks on the outer peripheral surface of a cylindrical, columnar, substantially semi-cylindrical, and substantially semi-cylindrical object. And having a pair of semicircular or semi-ring illumination means arranged at both ends of the inspection object, and having an imaging means at a predetermined height on the longitudinal center of the inspection object. As a result, since almost the same amount of light strikes each part of the surface of the inspection object, it is possible to suppress the occurrence of uneven brightness on the surface of the inspection object. For this reason, the inspection accuracy of abnormal portions such as scratches and cracks is improved. Moreover, since the illumination means has a semicircular shape or a semi-ring shape, it is easier to install than the ring-shaped illumination.

  According to the appearance inspection apparatus according to claim 2, in addition to the effect exhibited by the appearance inspection apparatus according to claim 1, brightness is achieved by having a mechanism that rotates the cylindrical and columnar inspection objects. The occurrence of unevenness is further suppressed, and the inspection of the entire circumference of the cylindrical and columnar inspection objects can be performed with a small number of rotations.

  Embodiments of an appearance inspection apparatus according to the present invention will be described below with reference to the drawings.

  FIG. 1A is a perspective view showing an overall configuration of an appearance inspection apparatus 100 according to an embodiment of the present invention, and FIG. 1B is a front view thereof. This figure shows a state in which a substantially semi-cylindrical (that is, semi-cylindrical) inspection object W1 is being inspected. The illumination means 110 has a substantially semi-ring shape, and is arranged so that its virtual center substantially coincides with the virtual center VC of the inspection object W1 as shown in FIG. The light source of the illumination unit 110 is not particularly limited, but a white light emitting diode 112 that has a long life, consumes less power, generates less heat, and provides a sufficient amount of light is preferably used. In the example of FIG. 1A, the white light emitting diode 112 is used in an exposed state, but may be shielded with an acrylic plate for the purpose of diffusing light and preventing the white light emitting diode from becoming dirty. it can. In this case, the white light emitting diode 112 can be prevented from becoming dirty, and a good light amount can always be obtained simply by wiping the acrylic plate. The imaging means 120 is installed at a predetermined height on the longitudinal center of the inspection object W1. The imaging unit 120 is not particularly limited, but an industrial CCD camera is preferably used. On the other hand, for fine scratches, a blue light emitting diode and a normal CCD camera or an ultraviolet light emitting diode and an ultraviolet CCD camera are used.

  FIG. 2A is a perspective view showing the overall configuration of an appearance inspection apparatus 200 according to another embodiment of the present invention, and FIG. 2B is a front view thereof. In this figure, the state which is inspecting cylindrical object W2 is shown. The illumination unit 210 has a semi-ring shape, and is arranged so that the center thereof coincides with the center C of the inspection object W2 as shown in FIG. The imaging means 220 is installed at a predetermined height on the longitudinal center of the inspection object W2. In addition, two support rods 230 that are pivotally supported in parallel at intervals smaller than the diameter of the inspection object W2 are provided, and the inspection object W2 is placed thereon. Then, by rotating the two support rods 230, the object W2 placed thereon can be rotated. Therefore, the entire circumference of the inspection object W2 can be easily inspected.

  FIG. 3 is a perspective view showing the overall configuration of an appearance inspection apparatus 300 according to another embodiment of the present invention. In this figure, the state which is inspecting cylindrical object W3 is shown. The illumination means 310 has a semicircular shape. The imaging means 320 is installed at a predetermined height on the longitudinal center of the inspection object W3. Also in this embodiment, since the same amount of light hits each part of the inspection object W3, brightness unevenness is eliminated and an accurate appearance inspection can be performed.

The perspective view and front view of the external appearance inspection apparatus of Example 1 in this invention. The perspective view and front view of the external appearance inspection apparatus of Example 2 in this invention. The perspective view of the external appearance inspection apparatus of Example 3 in this invention. The perspective view of the conventional external appearance inspection apparatus.

Explanation of symbols

100, 200, 300, 400 ... visual inspection devices 110, 210, 310, 410 ... illumination means 120, 220, 320, 420 ... imaging means 230 ... support rods W1, W2, W3, W4 ... Inspected object

Claims (2)

In an appearance inspection apparatus for inspecting scratches and cracks on the outer peripheral surface of a cylindrical, columnar, substantially semi-cylindrical, substantially semi-cylindrical object,
A pair of illumination means having a semicircular shape or a semi-ring shape disposed at both ends of the inspection object;
An appearance inspection apparatus having an imaging means at a predetermined height on the longitudinal center of the inspection object. The appearance inspection apparatus according to claim 1, further comprising a mechanism for rotating the cylindrical and columnar inspection objects.

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