JP2009122037A - Appearance inspecting device of chains and appearance inspecting method using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an appearance inspecting device of chaind and an appearance inspecting method using it, while extracting external defect and surface defect correctly, and detecting faulty defect with a high degree of accuracy and attempting to miniaturize well the dimensions against a test object. <P>SOLUTION: Since the appearance inspecting device of chains is equipped with a ring type illuminating means 110 illuminating the plane of a chain C vertically, an imaging means 120 installed so as to face the chain C from a central hole 112 on the ring type illuminating means 110, and a ring type low-angle illuminating means 130 which irradiates the tilted plane C3 of the chain C from a direction of acute angle and deployed closer to the chain C than the ring type illuminating means 110 to irradiate irradiating light of hue different from the irradiating light from the ring type illuminating means 110, thus, the problem can be solved. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a chain visual inspection apparatus and method used when performing visual inspection of a product to be inspected such as a link plate and a connecting pin in a chain manufacturing site. The present invention relates to a chain appearance inspection apparatus and method for irradiating a product with light and inspecting an external appearance defect and a surface defect of the component to be inspected by a reflection image thereof.

  Conventionally, as a chain appearance inspection at the chain manufacturing site, monochromatic light was irradiated on the chain surface, and black and white image processing such as binarization processing was performed on the reflected image to detect defects such as external defects. (For example, refer to Patent Document 1).

JP 2007-271510 A

However, since the conventional visual inspection apparatus performs black-and-white image processing, only lightness information can be used among the three pieces of information of hue, saturation, and lightness possessed by light. Therefore, when the captured black and white raw image is separated with a given lightness as a threshold, depending on the state of the plane, for example, whether it is rough or mirrored, the reflected image from the plane and the reflected from the inclined plane There was a problem that images could not be separated accurately and an accurate appearance inspection could not be performed.
In addition, when the appearance inspection device is enlarged for the chain that is the object to be inspected and it is attempted to perform inspection at the same time as manufacturing in the production line, sufficient space for installing the appearance inspection device cannot be secured. There was a problem.

  Therefore, the technical problem to be solved by the present invention, that is, the object of the present invention, is to accurately extract external defects and surface defects, and to detect defective defects and inscriptions engraved on the chain with high accuracy. Another object of the present invention is to provide a chain appearance inspection apparatus that is sufficiently reduced in size with respect to the size of an object to be inspected and an appearance inspection method using the same.

First, according to the first aspect of the present invention, in a chain appearance inspection apparatus using color image processing, ring-type illumination means for irradiating the plane of the chain vertically, and a central hole of the ring-type illumination means, the chain The imaging means installed so as to face the surface, and the inclined surface of the chain is irradiated from an acute angle direction, is installed closer to the chain than the ring type illumination means, and is different from the irradiation light of the ring type illumination means The present invention solves the above-mentioned problems by having a ring-type low-angle illuminating unit that emits hue irradiation light.
In the present invention, “irradiating from an acute angle direction” means that the irradiation light has an acute angle with respect to the plane of the outer link of the chain that is the object to be inspected.

  The invention according to claim 2 is the chain appearance inspection apparatus according to claim 1, wherein the irradiation light of the link type illumination means and the irradiation light of the ring type low angle illumination means have a complementary color relationship. Thus, the above-described problem is further solved.

  The invention according to claim 3 is the chain appearance inspection apparatus according to claim 1 or 2, wherein the side surface of the chain is vertically irradiated and has the same hue as the irradiation light of the ring-type low-angle illumination means. This problem is further solved by having bar-type illumination means for emitting the irradiation light.

  According to a fourth aspect of the present invention, in the chain appearance inspection apparatus according to any one of the first to third aspects, at least one of the ring-type illumination means, the ring-type low-angle illumination means, and the bar-type illumination means. The light emission diode (hereinafter referred to as “LED”) is one light source, which further solves the above problem.

  In the chain appearance inspection method using color image processing, the invention according to claim 5 includes a first step of vertically irradiating the plane of the chain with a ring illumination unit, and a center of the ring illumination unit. A second step of imaging the chain by an imaging means installed so as to face the chain from a hole; and the irradiation light of the ring-type illumination means, which is installed closer to the chain than the ring-type illumination means. The above-mentioned problem is further solved by including a third step of irradiating the inclined surface of the chain from an acute angle direction by ring-type low-angle illumination means for emitting irradiation light of different hues.

According to the invention according to claim 1 or claim 5, in the appearance inspection apparatus for a chain using color image processing or the appearance inspection method using the same, the ring-type illumination means for irradiating the plane of the chain vertically The imaging means installed so as to face the chain from the central hole of the ring-type illumination means, and the inclined surface of the chain is irradiated from an acute angle direction, and is installed closer to the chain than the ring-type illumination means And a ring-type low-angle illumination unit that emits illumination light having a hue different from the illumination light of the ring-type illumination unit, so that the brightness of the light when processing an image captured by the imaging unit It is possible to use not only the information of hue but also the information of hue and saturation, even if the reflected light from the normal part and the reflected light from the bad part are the same The information of hue and saturation, since discernible respectively, the defect contour defects and surface of the chain can be accurately detected.
Furthermore, even if the light quantity of each illumination means changes or even if the surface condition of the chain changes, the reflected light and defects from normal locations can be detected by using information on light brightness, hue, and saturation. Since the reflected light from various points can be identified, it is possible to accurately detect the outer shape defect and the surface defect of the chain.
In addition, not only external defects and surface defects, but also the presence / absence and shape of the chain's model number and company logo engraved at a predetermined location on the chain can be accurately detected and inspected, so quality control Accuracy can be significantly improved.

  According to the invention of claim 2, in synergy with the effect of the invention of claim 1, the illumination light of the link type illumination means and the illumination light of the ring type low angle illumination means have a complementary color relationship. As a result, the reflected light from the former irradiation light and the reflected light from the latter irradiation light do not mix to produce an intermediate color. Etc. can be detected more accurately.

  Further, according to the invention according to claim 3, in synergy with the effect of the invention according to claim 1 or 2, the side surface of the chain is irradiated vertically, and the irradiation light of the ring type low angle illumination means By irradiating light to the layered part of the chain that is the inspected product, it is possible to detect the outer shape defect of the inner link more accurately. Can do.

  Further, according to the invention according to claim 4, in synergy with the effect produced by the invention according to any one of claims 1 to 3, the ring-type illumination means, the ring-type low-angle illumination means, and the bar-type illumination are provided. Since at least one light source of the means is an LED, the LED is made of a solid structure called a pn junction using a semiconductor, and in this structure, the energy of electrons is directly converted into light energy. Because it emits light and does not require the intervention of heat or motion macroscopically, it has excellent durability, impact resistance, long life, and high efficiency, and the size of the object to be inspected In contrast, the size can be sufficiently reduced.

  A chain appearance inspection apparatus using color image processing and an appearance inspection method using the same according to the present invention face a chain from a ring-type illumination unit that irradiates the plane of the chain vertically and a central hole of the ring-type illumination unit. The imaging unit and the inclined surface of the chain are irradiated from an acute angle direction, and are installed closer to the chain than the ring illumination unit, and emits irradiation light with a hue different from that of the ring illumination unit The ring-type low-angle illumination means that can accurately detect external defects and surface defects and detect defective defects with high accuracy. But it doesn't matter.

  For example, the chain visual inspection apparatus of the present invention has no problem in visual inspection regardless of whether the chain is installed vertically to the chain to be inspected or installed horizontally. There is no problem whether the chain is stationary with respect to the appearance inspection device or traveling.

An embodiment of the present invention will be described with reference to FIGS.
Here, FIG. 1 is a front view of a chain appearance inspection apparatus according to an embodiment of the present invention, and FIG. 2 is a side view of the chain appearance inspection apparatus shown in FIG. FIG. 3 is an example of a captured image of a chain having a defect captured by the chain appearance inspection apparatus according to the present embodiment.

  As shown in FIGS. 1 and 2, the chain appearance inspection apparatus 100 according to the present embodiment includes a ring-type illumination unit 110 that irradiates the plane of the chain C vertically and a central hole 112 of the ring-type illumination unit 110. The image pickup means 120 is installed so as to face C. The image pickup means is not particularly limited as long as it can pick up a color image clearly. For example, a color CCD camera or the like can be used.

  For example, an inclined surface such as the caulking portion C3 of the pin C2 of the chain C can be irradiated from an acute angle direction with respect to the plane of the outer link C1 of the chain C, and is larger than the outer diameter of the ring illumination unit 110. A ring-type low-angle illuminating unit 130 has an inner diameter and is closer to the chain C which is an object to be inspected than the ring-type illuminating unit 110.

  Here, the illumination light from the ring illumination unit 110 and the illumination light from the ring low angle illumination unit 130 have different hues. In the present embodiment, each illumination means uses an illumination device using LEDs. Therefore, from the viewpoint of easy availability and cost of the illumination device, the irradiation light of the ring type illumination means 110 is blue, and the irradiation light of the ring type low angle illumination means 130 is red.

  However, for example, by using irradiation light having a complementary color relationship such that the irradiation light of the ring-type illumination unit 110 is blue and the irradiation light of the ring-type low-angle illumination unit 130 is yellow, the ring-type illumination unit 110 The reflected light from the irradiated light and the reflected light from the light emitted from the ring-type low-angle illuminating means 130 are mixed to produce a neutral color, and the reflected light looks more vibrant and looks vivid. Etc. can be detected more accurately, and the effect is enormous.

  Here, a specific structure of the ring illumination unit 110 used in the present embodiment will be described. The ring-type illumination means 110 is obtained by winding an LED on a long flexible substrate directly around the outer periphery of a light guide diffuser plate made of a ring-shaped acrylic plate and subjected to a reflective film processing such as dot printing on one side. It is fixed. As a result, the light emitted from the LED is refracted and scattered in a complicated manner immediately after the light emission, and the light spreads over the entire light guide plate, and uniform diffused light in a direction substantially perpendicular to the light guide plate is obtained as a plane of the chain C that is the inspection object. Can be irradiated. That is, the ring type illumination means 110 is a surface emitting source.

  Furthermore, by sticking aluminum foil on the inner peripheral wall of the center hole 112 of the ring-shaped acrylic plate, light leakage from the inner wall surface of the center hole of the light guide plate is suppressed, and the irradiation efficiency (injected from the LED) The ratio of the amount of light emitted from the light guide plate surface to the total amount of light) can be improved.

  Next, a specific structure of the ring-type low-angle illumination unit 130 used in this embodiment will be described. The ring-type low-angle illuminating means 130 has a ring-shaped aluminum outer shape material having an inner diameter larger than the outer diameter of the ring-type illuminating means 110 toward the center of the ring, and the irradiation angle is acute with respect to the plane formed by the ring In this way, the LED is embedded. That is, the ring-type low angle illumination means 130 is a direct light source.

  Further, as shown in FIG. 2, two bar-type illumination means 140 that vertically illuminate the side surface of the chain C are installed so as to face the side of the chain C. The bar-type illumination unit 140 is a direct light source having a configuration in which LEDs are arranged at a high density on a linear substrate. And the irradiation light of the bar-type illumination means 140 has the same hue as the irradiation light of the ring-type low-angle illumination means 130. By installing this bar-type illumination means 140, light is irradiated to the layered portion of the chain C, which is the product to be inspected, so that the outer shape defect of the inner link C4 can be detected more accurately, and the effect is enormous. It is.

  Next, a method of detecting an outer shape defect and a surface defect using the chain appearance inspection apparatus of this embodiment will be described with reference to FIG. FIG. 3 is a diagram schematically showing black and white color images when the chain is imaged from the front by the chain appearance inspection apparatus of the present embodiment.

  First, a method for detecting surface defects will be described. As shown in FIG. 3A, the average density is calculated while moving the detection area (segment) having a small square area within the measurement area. Then, a segment having a density difference equal to or greater than the threshold is detected as having scratches. In FIG. 3A, a red scratch appears as a reflected light of the irradiation light of which the scratch on the surface is red against the blue background which is the reflected light from the surface of the outer link C1 of the chain C. At this time, since the hue of the irradiation light is different from red and blue, even if the reflected light from the surface and the reflected light from the scratch have the same brightness, it can be determined from the information of hue and saturation.

  Next, a method for detecting an external defect will be described. As shown in FIG. 3B, a rectangular measurement area is scanned to measure a plurality of edge positions, that is, the outline of the outline in the measurement area, and the width between the measurement area B and the outline of the outline is compared. Then, a place having a predetermined width or more is defined as a defective portion. Also in this case, since the hue of the irradiation light is different from red and blue, even if the reflected light from the surface and the reflected light from the defective portion of the outer shape have the same brightness, it can be discriminated from the information of hue and saturation. .

  As described above, according to the chain appearance inspection apparatus and the appearance inspection method using the same according to the present invention, the outer shape defect and the surface defect are accurately extracted, and the defect defect or the predetermined position of the chain is engraved. The presence / absence, shape, etc. of the stamp can be detected with high accuracy, and the size of the chain, which is the object to be inspected, can be sufficiently reduced, and the effect is enormous.

The front view of the external appearance inspection apparatus of the chain of this invention. The side view when the external appearance inspection apparatus of the chain shown in FIG. 1 is seen from arrow II direction. The figure which shows an example of the captured image of the chain which has the defect which the appearance inspection apparatus of the chain of this invention imaged.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Chain external appearance inspection apparatus 110 ... Ring type illumination means 112 ... Center hole 120 ... Imaging means 130 ... Ring type low angle illumination means 140 ... Bar type illumination means C ... Chain C1 ... outer link C2 ... pin C3 ... caulking part C4 ... inner link

Claims (5)

In the appearance inspection device for chains using color image processing,
A ring illumination means for irradiating the plane of the chain vertically;
Imaging means installed so as to face the chain from a central hole of the ring-type illumination means;
Ring-type low angle that irradiates the inclined surface of the chain from an acute angle direction, and is disposed closer to the chain than the ring-type illumination means, and emits illumination light having a hue different from the illumination light of the ring-type illumination means An appearance inspection apparatus for a chain, comprising: an illumination unit.   2. The chain appearance inspection apparatus according to claim 1, wherein the irradiation light of the link type illumination means and the irradiation light of the ring type low angle illumination means have a complementary color relationship.   3. A bar-type illumination unit that irradiates a side surface of the chain vertically and emits irradiation light having the same hue as the irradiation light of the ring-type low-angle illumination unit. Appearance inspection device of the described chain.   4. The chain appearance inspection according to claim 1, wherein at least one of the ring-type illumination unit, the ring-type low-angle illumination unit, and the bar-type illumination unit is a light-emitting diode. apparatus. In the chain appearance inspection method using color image processing,
A first step of vertically irradiating the plane of the chain with a ring illumination means;
A second step of imaging the chain by imaging means installed so as to face the chain from a central hole of the ring illumination means;
The inclined surface of the chain is set in an acute angle direction by ring-type low-angle illumination means that is installed closer to the chain than the ring-type illumination means and emits illumination light having a hue different from the illumination light of the ring-type illumination means. And a third step of irradiating from the chain.

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