JP2013257245A - Inspection device for articles - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inspection device for articles capable of accurately performing inspection of articles formed in ring shapes in a short time.SOLUTION: A stage 12 on which a ring-shaped article 10 is placed is formed with a first light transmission part whose inner diameter is set to be larger than an inner diameter of a hole of the ring-shaped article 10 and smaller than an outer diameter of the article 10 and penetrating up and down. The stage 12 is formed with a plurality of second light transmission parts that penetrate up and down and extend radially from the first light transmission part. Provided are first lighting means 14 for emitting light to the stage 12 from below and a first camera 18 for taking a projected image formed by light emitted from the first lighting means 14 from above the stage 12. A contour dimension of the ring-shaped article 10 is measured from the image taken by the first camera 18.

Description

  The present invention relates to an inspection apparatus for an article formed in a ring shape.

  For example, forged ring-shaped articles used for the inner ring and outer ring of rolling bearings, etc., the dimensions of various inspection items such as inner diameter, outer diameter, thickness, roundness, thickness deviation, etc. are within the tolerances of preset standards. It is shipped as a product after checking whether or not it fits inside. In this inspection, since the operator has manually measured the dimensions of various inspection items using a dial gauge, the inspection takes time and there is a problem in that the inspection accuracy varies due to the difference in the skill level of the operator. there were. Therefore, as disclosed in Patent Document 1, the ring-shaped article placed on the conveyor is irradiated with light from the side, and the ring is projected from the projection image of the ring-shaped article captured by the CCD camera disposed on the opposite side. A device for measuring the shape of a shaped article has been proposed.

JP 2010-2232 A

  In the inspection apparatus disclosed in Patent Document 1, when measuring the outer shape, roundness, etc. of a ring-shaped article, it is necessary to rotate the ring-shaped article and image the entire article, which increases the inspection time. Difficulties are pointed out. In addition, the inspection apparatus disclosed in Patent Document 1 cannot measure the inner diameter and uneven thickness of the ring-shaped article, and there is a problem that another inspection is required. Furthermore, when a ring-shaped article to be forged is punched out, burrs may protrude from the edge of the hole outward in the axial direction. Therefore, when a ring-shaped article is placed on a conveyor with burrs, the ring-shaped article is tilted and a measurement error occurs, so that a high inspection accuracy cannot be guaranteed.

  That is, the present invention has been proposed to solve this problem in view of the problems inherent in the prior art, and an article that can accurately inspect a ring-shaped article in a short time. An object of the present invention is to provide an inspection apparatus.

In order to overcome the above-mentioned problems and achieve an intended object, an inspection apparatus for an article according to the invention of claim 1 comprises:
An inspection device for a ring-shaped article,
A stage on which the article with the hole opening facing up and down is placed;
A first light transmitting portion formed on the stage, penetrating vertically, and facing a hole of the article placed on the stage;
A second light transmission part formed on the stage and penetrating vertically, the hole facing the inside of the first light transmission part and the outer edge of the article placed on the stage facing;
Illumination means for irradiating the stage with light from above or below;
An imaging unit that opposes an illuminating unit across the stage and captures a projection image formed by irradiation light from the illuminating unit;
The gist of the invention is that it comprises a recognition means for recognizing the shape of the article from the image picked up by the image pickup means.

  According to the first aspect of the present invention, since the projection image is picked up from the opening direction of the hole in the article, the shape of the article can be recognized in a short time without rotating the article. That is, based on the recognized shape of the article, values of various inspection items such as the inner diameter and roundness of the article can be obtained. Further, by allowing the burr generated at the edge of the hole in the article to face the first light transmitting portion formed on the stage, the article can be placed on the stage without being inclined, and the inspection accuracy can be improved.

In the invention which concerns on Claim 2, the 2nd illumination means which irradiates light from the side to the said stage,
A second imaging unit that faces the second illumination unit across the stage and captures a projection image formed by the irradiation light from the second illumination unit;
A groove formed on the article placement surface of the stage and capable of passing the irradiation light from the second irradiation means to the second imaging means side;
The gist is that the recognition means is configured to recognize the shape of the article from the image picked up by the second image pickup means.
According to the invention of claim 2, the shape in the thickness direction can be recognized without changing the posture of the article on the stage.

The gist of the invention according to claim 3 is that a plurality of the second light transmission parts are formed on the stage so as to extend radially from the first light transmission part.
According to the invention which concerns on Claim 3, it can respond to the test | inspection of the goods from which a dimension differs.

The gist of the invention according to claim 4 is that a telecentric lens is attached to the imaging means.
According to the invention which concerns on Claim 4, an image without a distortion can be imaged by an imaging means, and test | inspection precision can be improved more.

  According to the article inspection apparatus of the present invention, the article can be inspected with high accuracy in a short time.

It is the schematic which shows the inspection apparatus of the articles | goods which concern on an Example. It is a schematic plan view which shows the stage of the inspection apparatus which concerns on an Example. It is the sectional view on the AA line of FIG. It is a principal part enlarged plan view which shows the relationship between the 2nd light transmission part formed in the stage which concerns on an Example, and a ring-shaped article. It is a control block diagram of the inspection apparatus which concerns on an Example. It is explanatory drawing shown in the state after image-processing the image imaged with the 1st camera which concerns on an Example. It is explanatory drawing shown in the state after image-processing the image imaged with the 2nd camera which concerns on an Example. It is principal part expansion explanatory drawing shown in the state after image-processing the image imaged with the 2nd camera which concerns on an Example.

  Next, a preferred embodiment of the article inspection apparatus according to the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a schematic diagram illustrating an article inspection apparatus according to an embodiment. The inspection apparatus is mounted on a stage 12 on which a forged ring-shaped article (article) 10 is mounted, and on the stage 12. Illuminating means 14 and 16 for irradiating the ring-shaped article 10 with light, cameras 18 and 20 for capturing projection images of the ring-shaped article 10 irradiated with light from the illuminating means 14 and 16, and imaging with the cameras 18 and 20 The processed image is processed to recognize the shape of the article and measure various inspection items such as inner diameter, outer diameter, thickness, roundness and thickness deviation, and whether each measured value is within the standard tolerance And an image processing device 22 for determining whether or not. Examples of the ring-shaped article 10 include those formed in a cylindrical shape.

  The stage 12 is made of a non-light transmissive metal rectangular plate material, the stage 12 has a uniform thickness, and the upper surface (article placement surface) on which the ring-shaped article 10 is placed is formed flat. The ring-shaped article 10 is placed with respect to the stage 12 in such a posture that the opening of the hole 10a is directed vertically. The stage 12 is set to be sufficiently larger than the ring-shaped article 10 to be inspected, and when the ring-shaped article 10 is placed on the stage 12, the ring-shaped article 10 protrudes outward from the stage 12. There is no such thing. In the center of the stage 12, a first light transmission portion 24 set to have an inner diameter larger than the inner diameter of the hole 10 a in the ring-shaped article 10 and smaller than the outer diameter of the ring-shaped article 10 is formed so as to penetrate vertically. The ring-shaped article 10 can be placed on the stage 12 with the hole 10a facing the inner side of the first light transmitting portion 24 (see FIGS. 2 and 3). In the embodiment, the first light transmission portion 24 is formed in a circular shape in accordance with the circular hole 10a of the ring-shaped article 10 formed in a cylindrical shape. Note that the difference between the inner diameter of the first light transmitting portion 24 and the inner diameter of the hole 10a in the ring-shaped article 10 takes into account the positioning accuracy of automatic conveying means (not shown) for placing the ring-shaped article 10 on the stage 12. Thus, it is set larger than the maximum error that may occur in the automatic conveying means. That is, even if a positional shift occurs in the ring-shaped article 10 placed by the automatic conveying means with respect to the placement position of the ring-shaped article 10 set on the stage 12, the entire hole 10 a of the ring-shaped article 10. Is always overlapped with the first light transmission part 24.

  The stage 12 is formed with a second light transmission portion 26 penetrating in the vertical direction. In the embodiment, a plurality of second light transmitting portions 26 communicating with the first light transmitting portion 24 on the center side are formed radially outward from the first light transmitting portion 24 in the radial direction. As shown in FIG. 2, each second light transmission portion 26 is configured so that the ring-shaped article 10 is placed on the stage 12 at a position where the entire hole 10 a overlaps the first light transmission portion 24. (Outer edge) Set to a length extending radially outward from 10b. In the embodiment, eight second light transmission portions 26 are formed at regular intervals in the circumferential direction, but the number of second light transmission portions 26 formed is an inspection item (for example, roundness) of the ring-shaped article 10. It may be set according to the accuracy to guarantee the above, and four or more are preferable. As shown in FIG. 4, the width dimension of the second light transmitting portion 26 is the arc of the outer peripheral edge 10 b of the ring-shaped article 10 from the projected image of the outer peripheral edge 10 b of the ring-shaped article 10 covering the second light transmitting portion 26. The curvature is set to a measurable value. For example, the width dimension of the second light transmission part 26 is set to about 10 mm.

  As shown in FIGS. 2 and 3, a long groove (groove) 28 opening upward is formed on the article placement surface of the stage 12. In the embodiment, in the region where the ring-shaped article 10 is placed on the stage 12, a plurality of long grooves 28 are formed in parallel. Each long groove 28 extends in a facing direction between a second illuminating means (second illuminating means) 16 and a second camera (second imaging means) 20 described later. The long groove 28 opens into the first light transmitting portion 24 or the second light transmitting portion 26 at a portion intersecting the first light transmitting portion 24 or the second light transmitting portion 26, and at the edge of the stage 12. It is configured to open to the outside, and the light irradiated from the side toward the stage 12 from the second illumination means 16 passes through the long groove 28, the first light transmission part 24, and the second light transmission part 26. 2 It is configured to be able to pass to the camera 20 side. In other words, in the embodiment, the long groove 28, the first light transmitting portion 24, and the second light transmitting portion 26 form an optical path that opens upward so that light can pass from one end to the other end of the stage 12.

  As shown in FIG. 1, a first illuminating means (illuminating means) 14 is disposed below the stage 12, and the light emitted upward from the first illuminating means 14 illuminates the stage 12 from below. The Further, the second illumination means 16 is disposed on one side of the stage 12 facing the one end edge where the long groove 28 is opened, and the light emitted from the second illumination means 16 in the lateral direction illuminates the stage 12 from the side. Configured to illuminate. The first illumination unit 14 illuminates the first light transmission unit 24 and the second light transmission unit 26 formed on the stage 12, and the second illumination unit 16 is placed on the long groove 28 formed on the stage 12 and the stage 12. The ring-shaped article 10 can be illuminated up to a region above the upper end. Each illuminating means 14, 16 uses surface-emitting illumination that can irradiate parallel light to the first light transmitting portion 24 and the second light transmitting portion 26 or the long groove 28 and the ring-shaped article 10, and as its light source, An LED, a fluorescent lamp, and other various lamps can be used.

  A first camera (imaging unit) 18 capable of capturing a projection image formed by the irradiation light from the first illumination unit 14 is disposed above the stage 12, and an image captured by the first camera 18 is displayed. The image processing apparatus 22 is configured to be captured (see FIG. 5). Further, a second camera (second imaging unit) capable of capturing a projection image formed by the irradiation light from the second illumination unit 16 on the other side opposite to the second illumination unit 16 with the stage 12 interposed therebetween. ) 20 is arranged, and an image captured by the second camera 20 is captured by the image processing device 22. As each of the cameras 18 and 20, a camera equipped with an image sensor such as a CCD sensor is preferably used. Each camera 18 and 20 is equipped with a telecentric lens 30 configured so that the principal ray is parallel to the optical axis, and is irradiated from the corresponding illuminating means 14 and 16 to be irradiated with the first light transmitting portion 24. Only the components parallel to the optical axis of the light that has passed through the second light transmitting section 26 or the long groove 28 are imaged by the cameras 18 and 20.

  The image processing device 22 to which both the cameras 18 and 20 are connected is an image processing unit (recognizing means) 32 that obtains the contour shape of the ring-shaped article 10 by performing image processing on images captured by the cameras 18 and 20. Measurement unit 34 for measuring various inspection items such as outer diameter, inner diameter, thickness, roundness, and thickness deviation from the contour shape of ring-shaped article 10 obtained by image processing unit 32, and measurement by measurement unit 34 And a determination unit 36 that determines whether or not the measured values of the various inspection items are within tolerances with respect to a preset standard value (see FIG. 5). Although not shown, the image processing device 22 is connected to display means for displaying the result determined by the determination unit 36. Examples of the image processing include binarization processing and multi-value processing, and various other processing such as making it possible to recognize a shape from a black and white image or a black and white image obtained by the processing is adopted. Can do.

(Effects of Example)
Next, the operation of the article inspection apparatus of the present embodiment configured as described above will be described.

  2 and 3, the ring-shaped article 10 is placed on the article placement surface of the stage 12 so that the entire hole 10a overlaps the first light transmitting portion 24, and the inner peripheral edge of the hole 10a is the first edge. 1 It mounts so that it may face the inner side of the light transmissive part 24. FIG. Thus, the article 10 can be prevented from being tilted by the burr generated at the edge of the hole 10 a of the ring-shaped article 10, and the ring-shaped article 10 is placed with the lower surface parallel to the stage 12. obtain. In a state where the ring-shaped article 10 is placed on the stage 12, the light from the first illumination unit 14 is irradiated onto the stage 12 from below, and a projection image formed by the irradiation light is projected from the upper side of the stage 12 to the first. The image is captured by the camera 18 and taken into the image processing device 22. The captured image captured by the image processing device 22 is subjected to image processing by the image processing unit 32, and an image of the contour shape of the ring-shaped article 10 is obtained. FIG. 6 shows a processed image processed by the image processing unit 32, and a portion where light is blocked by the stage 12 and the ring-shaped article 10 in the imaging region S1 of the first camera 18 is a dark part (FIG. , And the portion where the light has passed through the hole 10a and the second light transmitting portion 26 of the ring-shaped article 10 appears as a bright portion (outlined portion in the figure).

  The measurement unit 34 of the image processing device 22 measures the inner diameter of the ring-shaped article 10 based on the boundary line L1 between the bright part and the dark part corresponding to the hole 10a of the ring-shaped article 10 in the processed image shown in FIG. And the center coordinates of the hole 10a are obtained. The measuring unit 34 measures the outer diameter of the ring-shaped article 10 based on the boundary line L2 between the bright part corresponding to the plurality of second light transmitting parts 26 and the dark part on the hole 10a side, and the center of the outer diameter. Get the coordinates. Here, as shown in FIG. 4, the width of the second light transmission part 26 of the embodiment is set to a dimension that can determine the curvature of the outer peripheral edge 10b of the ring-shaped article 10 that covers the second light transmission part 26. Therefore, the outer diameter and center coordinates of the ring-shaped article 10 can be obtained by calculating a circle connecting the eight boundary lines L2 based on the curvature measured from each boundary line L2. Further, the measurement unit 34 measures the thickness deviation of the ring-shaped article 10 from the center coordinates of the inner diameter and the outer diameter, and measures the roundness by measuring the outer diameter at a plurality of locations. Then, the determination unit 36 of the image processing device 22 determines whether or not the obtained measurement values of the various inspection items are within tolerances with respect to a preset standard value.

  Next, with the first illumination unit 14 turned off, the stage 12 is irradiated with light from the second illumination unit 16 from the side, and a projection image formed by the irradiation light is projected to the other side of the stage 12. The image is picked up by the second camera 20 and taken into the image processing device 22 from the side. The captured image captured by the image processing device 22 is subjected to image processing by the image processing unit 32, and an image of the contour shape of the ring-shaped article 10 is obtained. FIG. 7 shows a processed image processed by the image processing unit 32, and a portion where light is blocked by the stage 12 and the ring-shaped article 10 in the imaging region S2 of the second camera 20 is a dark part (FIG. In the figure, the portion where light is not blocked by the stage 12 and the ring-shaped article 10 appears as a bright portion (outlined portion in the figure). The light emitted from the second illuminating means 16 and incident on the long groove 28 from one opening passes through the long groove 28, the first light transmitting portion 24 and the second light transmitting portion 26 to the other side of the stage 12. Therefore, the portion corresponding to the other opening of the long groove 28 appears as a bright portion. That is, since a portion corresponding to the lower surface located on the long groove 28 in the ring-shaped article 10 placed on the stage 12 appears as a boundary line L3 between the bright part and the dark part, the measurement unit 34 of the image processing apparatus 22 Based on the boundary line L3 and the boundary line L4 between the bright part and the dark part corresponding to the upper surface of the ring-shaped article 10, the thickness of the ring-shaped article 10 is measured. Then, the determination unit 36 of the image processing device 22 determines whether or not the obtained thickness measurement value is within a tolerance with respect to a preset standard value.

  In the inspection apparatus according to the embodiment, the outline shape of the ring-shaped article 10 is recognized only by capturing projected images of the ring-shaped article 10 from above and from the side with the ring-shaped article 10 placed on the stage 12. In addition, various inspection items such as the inner diameter, outer diameter, thickness, roundness and thickness deviation can be measured from the recognized contour shape, and the time required for the inspection can be shortened. Further, since the first light transmission portion 24 larger than the inner diameter of the hole 10a of the ring-shaped article 10 is formed on the stage 12, even if burrs are generated at the edge of the hole 10a of the ring-shaped article 10 The ring-shaped article 10 is not tilted by the burr, and high inspection accuracy can be guaranteed. Furthermore, since the second light transmission part 26 that transmits the light from the first illumination means 14 is formed in a radial shape, it can correspond to the ring-shaped article 10 of various dimensions, and by changing the type of the ring-shaped article 10 If the change in the outer diameter is within a predetermined range, it can be handled without replacing the stage 12. Furthermore, since the first camera 18 and the second camera 20 are equipped with the telecentric lens 30, the distortion of the images taken by the cameras 18 and 20 is small, and the boundary lines L1, L2, L3, L4 The measurement accuracy of the dimension based on can be further increased.

  In the inspection apparatus according to the embodiment, since the accurate contour shape of the ring-shaped article 10 can be recognized from the image captured by the second camera 20 as shown in FIG. It can be determined whether the surface is inclined in the axial direction. Accordingly, it is possible to measure the taper angle of the ring-shaped article 10 whose outer peripheral surface is tapered.

  Here, in the embodiment, the stage 12 is made of a metal non-light transmissive plate material, and the first light transmissive part 24 and the second light transmissive part 26 through which light from below can pass are formed. Although the projection image of the ring-shaped article 10 placed on the stage 12 is configured to be captured, the projection image of the ring-shaped article 10 is captured by light from below by making the stage 12 made of a light-transmitting synthetic resin. It is possible to do. However, the forged ring-shaped article 10 to be inspected in the embodiment has a rough surface, and when the ring-shaped article 10 is placed on the stage 12, the stage surface is scratched and whitened, and the transparency is deteriorated over time. Therefore, the contour shape may not be accurately recognized from an image obtained by capturing the projected image of the ring-shaped article 10 by reducing it. On the other hand, by adopting the metal stage 12, even if the surface of the stage 12 is damaged by the ring-shaped article 10, the light passing through the first light transmission part 24 and the second light transmission part 26 is affected. There is an advantage that the contour shape of the ring-shaped article 10 can be accurately recognized over a long period of time.

[Example of change]
The present invention is not limited to the configuration of the embodiment, and various modifications are possible. For example, the following configurations can be adopted.
(1) In the embodiment, a long groove is formed on the stage. However, the long groove may be provided when the thickness of the ring-shaped article needs to be measured. Also, the second camera and the second illumination means may be provided when it is necessary to measure the thickness of the ring-shaped article.
(2) In the embodiment, the stage has a rectangular shape, but the shape of the stage is not limited to a rectangular shape, and may be circular or other shapes as long as a ring-shaped article can be placed thereon. .
(3) In the embodiment, a cylindrical article is used as the article. However, the article may have a rectangular tube shape, and the first light transmitting portion and the second light transmitting section may be used depending on the shape of the article. What is necessary is just to set the shape of a part.
(4) In the embodiment, the case where one through hole that connects the first light transmitting portion and the second light transmitting portion is formed in the stage has been described. However, the first light transmitting portion and the second light transmitting portion are in communication. Individual through holes may not be used.
(5) In the embodiment, the case where a plurality of second light transmission portions and long grooves are formed has been described, but the number of the second light transmission portions and long grooves may be one.
(6) In the embodiment, the second light transmission portion is formed as a long hole extending radially, but the opening shape is not limited as long as the outer edge of the article placed on the stage faces. For example, the structure which formed the round hole as a 2nd light transmissive part in the predetermined pattern outside a 1st light transmissive part is employable.
(7) In the embodiment, the first illumination means is arranged below and the first camera is arranged above the stage, but the first camera is arranged above the stage and the first camera is arranged below. And the structure which irradiates the light from a 1st illumination means to a stage from upper direction, and images the projection image formed with this irradiation light with a 1st camera from the lower side of a stage can be employ | adopted.
(8) The image processing apparatus of the embodiment measures the outline dimensions (various inspection items) of the ring-shaped article from the image captured by the camera, and determines whether or not the measurement value is within the tolerance with respect to the standard value. Although it is configured to determine, it is possible to omit the determination unit.

10 ring-shaped article (article), 10a hole, 12 stage 14 first illumination means (illumination means), 16 second illumination means (second illumination means)
18 First camera (imaging means), 20 Second camera (second imaging means)
24 1st light transmission part, 26 2nd light transmission part, 28 Long groove (groove)
30 Telecentric lens, 32 Image processing unit (recognition means)

Claims (4)

An inspection device for an article (10) molded in a ring shape,
A stage (12) on which the article (10) with the opening of the hole (10a) facing up and down is placed;
A first light transmitting portion (24) formed on the stage (12) and penetrating vertically, and a hole (10a) of the article (10) placed on the stage (12) faces inward;
An outer edge of the article (10) placed on the stage (12) is formed on the stage (12) and penetrates vertically, with the hole (10a) facing the inside of the first light transmission part (24). A second light transmitting portion (26) facing the surface;
Illuminating means (14) for irradiating the stage (12) with light from above or below;
An imaging means (18) that opposes the illumination means (14) across the stage (12), and that captures a projection image formed by the irradiation light from the illumination means (14),
An article inspection apparatus comprising: recognition means (34) for recognizing the shape of the article (10) from an image picked up by the image pickup means (18). Second illumination means (16) for irradiating the stage (12) with light from the side;
A second imaging means (20) that opposes the second illumination means (16) across the stage (12) and images a projection image formed by the irradiation light from the second illumination means (16). When,
A groove (28) formed on the article placement surface of the stage (12) and capable of passing the irradiation light from the second irradiation means (16) to the second imaging means (20) side;
The article inspection apparatus according to claim 1, wherein the recognition means (34) is configured to recognize the shape of the article (10) from an image captured by the second imaging means (20).   The article inspection apparatus according to claim 1 or 2, wherein a plurality of the second light transmission parts (26) are formed on the stage (12) so as to extend radially from the first light transmission part (24).   The article inspection apparatus according to any one of claims 1 to 3, wherein a telecentric lens (30) is attached to the imaging means (18, 20).

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