JP5302600B2 - Burr detection device for resin molded products - Google Patents

Description

  The present invention relates to a burr detection device for a resin molded product that detects a burr generated in a resin molded product, and in particular, detects a burr by imaging the resin molded product with an imaging device and processing the captured image. The present invention relates to an apparatus for detecting burrs in a molded resin product.

  The resin molded product may have burrs during the manufacturing process. Since burrs cause a reduction in the accuracy of the product, it is necessary to remove the products with burrs from the manufacturing process. Therefore, conventionally, in order to inspect the burrs, it has been performed to detect the burrs by capturing an estimated position of the burrs and performing image processing on the captured image. For example, Patent Document 1 (Japanese Patent Laid-Open No. 2002-96353) discloses a device that inspects the presence or absence of burrs by imaging a resin molded product with an imaging device and performing image processing on the resin molded product. Further, in Patent Document 2 (Japanese Patent Application Laid-Open No. 11-201739), an inspected molded product having a burr formed on the circumferential surface is rotated and imaged with an imaging camera from the rotational radial direction. An apparatus for discriminating defects due to the length of burrs is disclosed.

  As a molding method of a resin molded product, for example, injection molding in which a resin material is poured into a mold and then solidified is often used. In such a case, a thin burr is generated due to a molding problem. There is. Such a thin film-like burr may cause deformation or misalignment due to heat due to contact even if the wall thickness or protrusion is slight, and may cause problems to other parts and thus the product itself. Thin-film burrs are almost the same color as the component body, or the protrusion may be as small as several tens of microns, and the thickness and thickness of the component body vary depending on the location of the product. In the case of image processing using the processed image, detection is very difficult because there is almost no color difference or density difference. In particular, when the resin molded product that is the object of the shaft was visually inspected, it had to be rotated by the hand of the worker, leading to oversight of minute thin film-like burrs.

JP 2002-96353 A Japanese Patent Laid-Open No. 11-201739

As described above, when the burr detection using the conventional image processing is applied to the thin-film burr, since the burr thickness and the protrusion are slight, there is almost no color difference and density difference on the captured image, and the detection is possible. There was a problem that was very difficult.
Accordingly, an object of the present invention is to provide a resin-molded product burr detection device that can accurately detect a thin film burr that is difficult to detect.

Therefore, in order to solve such a problem, the present invention provides a burr detection device for a resin molded product that detects burrs generated in a resin molded product formed of a colored resin.
The burr is a thin-film burr whose projecting direction can be estimated with respect to the resin molded product,
An imaging device installed in a direction substantially orthogonal to the protruding direction and imaging the resin molded product;
Wherein across the resin molded product and the imaging device is located on the opposite side, and the installed in the optical axis or Raz likeness position of the imaging device, the following at least wavelength 500nm for the estimated position of the thin film burrs An illumination device that emits illumination light including a short wavelength, and
If the resin molded product has burrs, the illumination light emitted from the illumination device is scattered by the burrs, and an image of the scattered light incident on the imaging device is captured. Based on the image, the thin-film burrs The presence or absence is detected. In this case, preferably, the imaging device, the estimated position of the thin film burr, and the lighting device are positioned substantially in a straight line within a range in which illumination light from the lighting device does not directly enter the imaging device. In addition, the illumination device and the imaging device are arranged.

A resin molded product without a thin film burr reflects light by the surface that constitutes the end when illuminated with illumination light, but becomes dark when viewed from the opposite direction to the light and becomes dark when captured by an imaging device. Become. On the other hand, if there is a thin film-like burr, light is scattered by a thin film with refractive index fluctuations or minute irregularities on the surface when irradiated with illumination light. Only looks bright and shiny.
Therefore, in the present invention, when the thin burr is present by using the thin thickness of the thin burr and imaging the burr estimated part with the imaging device while irradiating with illumination light including at least a short wavelength, Since only the burr portion shines brightly, it becomes possible to detect a thin film-like burr with high accuracy by image processing.
In addition, by making the illumination light including at least a short wavelength, the scattering property of the illumination light becomes stronger, the brightness of the thin-film burrs in the captured image becomes higher, and the threshold value at the quantized brightness value is set higher. Can be easily extracted by binarization. On the other hand, the resin molded product is imaged brightly as a whole with red light having high transparency, but the luminance of the thin film-like burrs is lowered and is difficult to extract. Therefore, as described above, illumination light including at least a short wavelength is used. This makes it possible to improve the detection accuracy of the thin film burr.

Furthermore, the imaging apparatus has an optical system with a long focal length. Specifically, the image pickup apparatus, the focal length Ru 35~80mm der.
As described above, since the imaging device has an optical system with a long focal length, the viewing angle (view angle) is narrowed and the direct light of the illumination device is not received, so the contrast of the captured image is clear and the detection accuracy of the thin-film burrs is improved. Will improve.
Still further, the illumination light emitted from the illumination device is spot light or parallel light adjusted to an angle for irradiating within a predetermined range set in advance. Preferably, a condensing lens is attached to the lighting device so that the illumination light does not spread.
As a result, it is possible to improve the detection accuracy of the thin film-like burrs as described above.

In addition, an image processing apparatus to which a captured image captured by the imaging apparatus is input,
The image processing apparatus binarizes the captured image, and when the high brightness area of the processed image is equal to or larger than a preset area value or area ratio or a width in the vertical direction from the end surface of the resin molded product, A thin-film burr detector is provided that determines that the thin-film burr exists.
In this way, the image processing apparatus binarizes the captured image, and determines the presence or absence of thin film-like burrs based on the area value or area ratio of the high luminance region or the width in the vertical direction from the end face of the resin molded product. This makes it possible to reliably detect only the thin-film burrs that are brightly illuminated by the illumination light described above.

Furthermore, it is a burr detection device for a resin molded product that detects a chip generated in the resin molded product together with the thin film burr,
An image processing apparatus to which a captured image captured by the imaging apparatus is input;
The image processing apparatus includes a chip detection unit that stores in advance shape data of a resin molded product having no chip and detects the chip by pattern matching between the captured image and the shape data. And
In this way, by performing pattern matching of the captured image with the shape data in the image processing apparatus, it becomes possible to simultaneously detect the chipping of the resin molded product in addition to the thin film burrs.

As described above, according to the present invention, it is possible to accurately detect a thin-film burr that has been difficult to detect in the past. That is, by utilizing the thin thickness of the thin-film burrs and imaging the burrs estimation part with the imaging device while irradiating with illumination light including at least a short wavelength, only the burrs are present if burrs exist. Therefore, it is possible to detect a thin film-like burr with high accuracy by image processing.
Further, since the imaging apparatus has an optical system with a long focal length, the detection accuracy of the thin film-like burrs is improved. Similarly, the detection accuracy of the thin film-like burrs is improved by using the illumination light of the illumination device as spot light or parallel light adjusted to an angle within a predetermined range set in advance.

Further, the captured image is binarized by the image processing apparatus, and the presence or absence of a thin film-like burr is determined based on the area value or area ratio of the high luminance region or the width in the vertical direction from the end surface of the resin molded product. Only the thin film-like burrs brightly illuminated by the illumination light described above can be reliably detected.
Furthermore, by using the image processing apparatus to pattern-match the captured image with the shape data, it is possible to simultaneously detect the chipping of the resin molded product in addition to the thin film burrs.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, but are merely illustrative examples. Not too much.
1 is an overall configuration diagram of a burr detection device showing an embodiment of the present invention, FIG. 2 is an enlarged view of a main part of the burr detection device shown in FIG. 1, and FIG. 3 is an enlarged view of a portion B of FIG. FIG. 4 is a diagram showing a ring-shaped molded product to be inspected, and FIG. 5 is a diagram showing a processing flow in the burr detection device of this embodiment.
The resin molded product shown in this embodiment is limited to those formed of colored resin, and excludes transparent resin molded products. A translucent (for example, milky white) resin molded product is included. In particular, the present embodiment is suitably applied to a resin molded product formed by injection molding. The burrs that are detection targets are thin film burrs that can be estimated in the projecting direction with respect to the generation site in the resin molded product and the resin molded product.

With reference to FIG. 1 thru | or FIG. 3, the specific structure of the burr | flash detection apparatus which concerns on this embodiment is demonstrated.
As shown in FIG. 1, the burr detection device 1 holds a ring-shaped molded product 20 to be inspected and moves it as necessary, and imaging devices 5 and 6 for imaging the ring-shaped molded product 20. The illumination devices 7 and 8 installed on the opposite side of the imaging devices 5 and 6 across the ring-shaped molded product 20; the image processing device 10 electrically connected to the imaging devices 5 and 6; An illumination amplifier 12 connected to the illumination devices 6 and 7 and a controller 11 connected to the illumination amplifier 12 and connected to the image processing device 10 are provided.
In the present embodiment, the ring-shaped molded product 20 made of colored resin is shown as an example of the detection target, but the shape and the like are not limited to this. FIG. 4 shows a ring-shaped molded product. 4A is a plan view and FIG. 4B is a side view. The ring-shaped molded product 20 is a cylindrical resin molded product, and has a shape in which a plurality of holes 21 penetrating from the outside to the inside are provided at a predetermined pitch on the circumferential surface. The thin film burr 22 is generated on the inner surface of the hole 21.

  In FIG. 1, the structure of the holding mechanism is not particularly limited as long as it is a mechanism that holds the ring-shaped molded product 20 and moves it as necessary. In the present embodiment, the holding unit 4 that holds the ring-shaped molded product 20, the servo motor 3 that is connected to the holding unit 4 and rotates it, and the ring-shaped molded product 20 is linearly moved together with the servo motor 3. The rail 2 is provided. The servo motor 3 is provided with a rotary encoder that detects the amount of mechanical displacement of rotation. In the holding mechanism having such a configuration, the ring-shaped molded product 20 held by the holding unit 4 stops after being rotated to a predetermined angular position by the servo motor 3, and rotates again after imaging. After the necessary number of times of imaging, the rail 2 is moved from the front side to the back side on the rail. Then, the next ring-shaped molded product 20 moves to the imaging position and performs imaging similarly. It is possible to perform continuous automatic inspection by installing the holding unit 4 on the rail 2 continuously at regular intervals and circulating the holding unit 4.

One or a plurality of the imaging devices 5 and 6 are provided, and for example, a CCD camera or the like is used. As shown in FIGS. 2 and 3, the imaging devices 5 and 6 are arranged in a direction substantially orthogonal to the estimated burr protrusion direction. In FIG. 2A, the imaging device 5 and the illumination device 7 are installed to detect a thin film-like burr 22 in the A part in the figure.
That is, the angle θ ₁ between the burr protruding direction and the imaging direction of the imaging device 5 is set to approximately 90 °. The imaging devices 5 and 6 preferably have an optical system with a long focal length, and more preferably have a focal length of 35 to 80 mm.

One or a plurality of the illumination devices 7 and 8 are provided for one imaging device 5 and 6. As shown in FIGS. 2 and 3, the illumination devices 7 and 8 are arranged slightly shifted with respect to the optical axis (imaging direction) of the imaging devices 5 and 6. That is, the angle theta ₂ between the imaging direction and the illumination direction is made larger than 0 °. The angle θ ₂ is within a range in which the illumination light of the illumination devices 7 and 8 does not directly enter the imaging devices 5 and 6, and the imaging devices 5 and 6, the estimated position of the thin film burr, and the illumination devices 7 and 8 are approximately. It is preferable to set the angle so as to be positioned on a straight line. Preferably, the angle theta ₂ is a 10 to 20 °. The illumination devices 7 and 8 are devices that irradiate illumination light including at least a short wavelength. The illumination light is preferably blue light having a wavelength of 500 nm or less or white light containing blue. Furthermore, it is preferable that the illumination light is spot light or parallel light such as an LED set to irradiate within a predetermined range set in advance. Furthermore, it is preferable to attach a condensing lens to the illumination device so that the illumination light does not spread.
When there are a plurality of directions in which the shape is complicated and thin-film burrs are generated as in the ring-shaped molded product 20, a plurality of imaging units including an imaging device and an illumination device may be provided.

The image processing apparatus 10 receives images captured by the image capturing apparatuses 5 and 6 through an electric line, and performs a predetermined image process on the captured image by a burr detection unit (not shown) to form a thin film. Determine the presence or absence of burrs. In addition to the thin film-like burrs, when detecting the chipping of the ring-shaped molded product 20, a chipping detection unit (not shown) is also provided.
The controller 11 controls the lighting amplifier 12 to adjust lighting of the lighting devices 7 and 8.

Here, with reference to FIG. 5, the processing flow in the burr | flash detection apparatus of this embodiment is demonstrated. The following is a case where both burr detection and chipping detection of the ring-shaped molded product 20 are performed.
First, the burr protrusion direction is estimated based on the shape of the ring-shaped molded product 20 and the molding method (S1). The imaging devices 5 and 6 are arranged so that the imaging direction is substantially orthogonal to the estimated burr protrusion direction, and the illumination devices 7 and 8 are placed at positions slightly deviated from the optical axes of the imaging devices 5 and 6. Deploy. When the setting of the devices is completed, the ring-shaped molded product 20 is held by the holding unit 4, moved on the rail 2 to the inspection position, and an estimated burr position at a position corresponding to the imaging devices 5, 6 and the lighting devices 7, 8. After the ring-shaped molded product 20 is rotated by the servo motor 3 so as to come, this is stopped and the imaging devices 5 and 6 perform imaging (S2). At this time, the illumination devices 7 and 8 irradiate the burr estimated position with illumination light including at least a short wavelength. After imaging, the servo motor 3 is rotated to image the next imaging region. When all the imaging regions are completed, the rail 2 is moved to the release position, and the ring-shaped molded product 20 is released.

The picked-up images picked up by the image pickup devices 5 and 6 are input to the image processing device 10, and the image processing device 10 performs image processing on the picked-up images to detect thin film burrs. A thin film-like burr is considered to be a thin film having a refractive index fluctuation caused by thickness non-uniformity or a minute unevenness on the surface. When such a thin film is irradiated with light, the light is scattered not only in the straight direction but also in a direction deviating from the straight direction. On the contrary, the surface of the resin molded product is smooth in many cases, and when irradiated with light, it is strongly reflected in the specular reflection direction and is not scattered much in other directions. By using this difference in optical properties, a thin film-like burr generated at the end of the resin molded product can be detected.
That is, the resin molded product without a thin film-like burr reflects light by the surface constituting the end when illuminated by the illumination devices 7 and 8, but it becomes a shadow when viewed from the opposite direction to the light. When an image is captured by the devices 5 and 6, the image becomes dark. In many cases, the edge of the end face also has a rounded shape at the light wavelength level, and there is almost no diffracted light by the edge. When there is a thin film-like burr, when the illumination light is irradiated, the light is scattered by a thin film having a refractive index fluctuation or a minute unevenness on the surface. It looks bright and shiny.

Therefore, the image processing apparatus 10 binarizes the captured image (S3), and extracts a high-luminance region in the obtained processed image. The high luminance region is a portion considered to be a thin film burr for the above reason. Then, the high luminance area is compared with a preset set area (S4). The set area is stored in advance in the image processing apparatus 10 and is a threshold value for determining a predetermined high-luminance area as a burr. When comparing these, any of the area value or the area ratio may be used. In addition, as a threshold value as a determination criterion, a width in the vertical direction from the end surface of the resin molded product may be used. In this case, the width in the vertical direction from the preset end surface of the resin molded product and the resin molding obtained from the captured image are used. Compare the width in the vertical direction from the product end face.
When the high luminance region is equal to or larger than the set area (S5), it is determined that a thin film-like burr exists (with burr) (S8). If the high luminance region <the set area, then the chip determining unit (not shown) of the image processing apparatus 10 determines whether the ring-shaped molded product 20 is chipped. In this process, the shape data of the resin molded product having no chip is stored in the image processing device 20 in advance, and the captured image and the shape data are subjected to pattern matching processing (S6). Then, it is determined whether or not the captured image matches the shape data (S7). If they do not match, it is determined that there is a chip (S8). If they match, it is determined that there are no thin-film burrs and chips (burrs / no chips) (S9). Although the flow for detecting a chip after detecting a burr has been described here, a flow for detecting a burr after detecting a chip or a flow for detecting a burr and a chip simultaneously may be used.
If a thin film-like burr or chip is present, it is output as an NG signal via the controller 11 or the like, and this NG signal is used as a determination signal in an exclusion device (not shown) provided at the subsequent stage of the burr detection device 1. It is good to do. An exclusion apparatus is an apparatus which removes the ring-shaped molded product 20 in which a thin film-like burr | flash or a chip | tip exists from a manufacturing process.

According to the present embodiment, when the thin burr is thin, when the burr is present by imaging the burr estimated part with the imaging device while irradiating with illumination light including at least a short wavelength, Since only the burr portion shines brightly, it becomes possible to detect a thin film-like burr with high accuracy by image processing.
In addition, by making the illumination light including at least a short wavelength, the scattering property of the illumination light becomes stronger, the brightness of the thin-film burrs in the captured image becomes higher, and the threshold value at the quantized brightness value is set higher. Can be easily extracted by binarization. On the other hand, the resin molded product is imaged brightly as a whole with red light having high transparency, but the luminance of the thin film-like burrs is lowered and is difficult to extract. Therefore, as described above, illumination light including at least a short wavelength is used. This makes it possible to improve the detection accuracy of the thin film burr.

In addition, the imaging device and the illumination device are arranged so that the imaging device, the estimated position of the thin film burr, and the illumination device are in a substantially straight line within a range where illumination light from the illumination device does not directly enter the imaging device. By installing, it is possible to obtain a captured image in which the thin-film burrs and other parts can be clearly distinguished.
In addition, since the imaging device has an optical system with a long focal length, the viewing angle (viewing angle) is narrowed and the direct light of the lighting device is not received, so the contrast of the captured image is clear and the detection accuracy of thin film burrs is improved. To do.
Similarly, the detection accuracy of the thin film-like burrs is improved by using the illumination light of the illumination device as spot light or parallel light adjusted to an angle within a predetermined range set in advance.

In addition, the image processing apparatus binarizes the captured image, and determines the presence or absence of a thin film-like burr based on the area value or area ratio of the high-luminance region, thereby thinning the thin film with the illumination light described above. Only burrs can be reliably detected.
Furthermore, by using the image processing apparatus to pattern-match the captured image with the shape data, it is possible to simultaneously detect the chipping of the resin molded product in addition to the thin film burrs.

1 is an overall configuration diagram of a burr detection device showing an embodiment of the present invention. FIG. 2 is an enlarged view of a main part of the burr detection device shown in FIG. 1, wherein (a) is a perspective view and (b) is a plan view. It is the B section enlarged view of Drawing 2 (b). It is a figure which shows the ring-shaped molded product which is a test object, (a) is a top view, (b) is a side view. It is a figure which shows the processing flow in the burr | flash detection apparatus of this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Burr detection apparatus 2 Rail 3 Servo motor 4 Holding part 5, 6 Imaging apparatus 7, 8 Illumination apparatus 10 Image processing apparatus 11 Controller 12 Illumination amplifier 20 Ring-shaped molded product 21 Hole part 22 Thin-film burr

Claims (5)

In a resin molded product burr detection device that detects a burr generated in a resin molded product formed of a colored resin,
The burr is a thin-film burr whose projecting direction can be estimated with respect to the resin molded product,
An imaging device installed in a direction substantially orthogonal to the protruding direction and imaging the resin molded product;
Wherein across the resin molded product and the imaging device is located on the opposite side, and the installed in the optical axis or Raz likeness position of the imaging device, the following at least wavelength 500nm for the estimated position of the thin film burrs An illumination device that emits illumination light including a short wavelength, and
If the resin molded product has burrs, the illumination light emitted from the illumination device is scattered by the burrs, and an image of the scattered light incident on the imaging device is captured. Based on the image, the thin-film burrs An apparatus for detecting burrs in a molded resin product, characterized by detecting presence or absence.   2. The resin molded product burr detection device according to claim 1, wherein the imaging device has a focal length of 35 to 80 mm.   2. The burr detection device for a resin molded product according to claim 1, wherein the illumination light emitted from the illumination device is a spot light or a parallel light adjusted to an angle within a predetermined range set in advance. . An image processing apparatus to which a captured image captured by the imaging apparatus is input;
The image processing apparatus performs binarization processing on the captured image, and when a high-luminance region of the processed image is equal to or larger than a preset area value or area ratio or a width in the vertical direction from the end surface of the resin molded product 2. A resin-molded product burr detection device according to claim 1, further comprising a thin-film burr detector that determines that the thin-film burr is present. A resin molded product burr detection device for detecting chipping generated in the resin molded product together with the thin film burr,
An image processing apparatus to which a captured image captured by the imaging apparatus is input;
The image processing apparatus includes a chip detection unit that stores in advance shape data of a resin molded product having no chip and detects the chip by pattern matching between the captured image and the shape data. The burr detection device for a resin molded product according to claim 1 or 4 .

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