JP3224614B2 - Method and apparatus for measuring thickness of flange of container made of light-guiding material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for measuring the thickness of a flange made of a thin resin, such as a PET (polyethylene terephthalate) can.

[0002]

2. Description of the Related Art As thin resin containers, there are, for example, PET cans for food and PET cans for miscellaneous goods such as tennis balls, and most of them form a flange in a manufacturing process.
In many cases, an aluminum lid or the like is wound around the flange.

[0003] Therefore, in order to form a sealed state by performing accurate tightening, it is necessary to accurately measure the thickness of the flange to reduce its variation.

As means for measuring the flange thickness, there are conventionally a method of measuring with a mechanical measuring instrument such as a caliper and a micrometer, a method of performing image processing, and a method of measuring with a laser sensor. .

[0005]

In the case of measurement using the above-mentioned calipers or micrometer, there is a case where the measurement accuracy is not stable due to the individual difference of the measurer, and the measurement efficiency is low due to manual operation. There is a problem. Also, when using image processing, laser sensors, etc., very high precision is required for handling, which is not suitable for in-line measurement. However, there is a problem that accurate measurement may not be possible because the measurement may not be constant.

For example, as shown in FIG. 5, a flange 2 of a PET can 1 is illuminated by an illuminating device 3 and an image of the flange 2 is captured by a CCD camera 4 from the opposite side.
In some image processing, the thickness t of the flange 2A in the image 5 shown in FIG. 6 is measured.

In this case, if the pet can 1 is set to be inclined as shown in FIG. 7, the image 2A of the flange 2 captured by the CCD camera 4 becomes thicker than it actually is.

[0008] Also, as shown in FIG. 8, even when the flange 2 is curved, the image 2A is similarly projected thicker than it actually is.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has been made in consideration of the case where the thickness of the flange when the container is formed of a light-guiding material, for example, when the container is not set accurately. , If the flange is curved,
It is an object of the present invention to provide a method and an apparatus for quickly and accurately measuring the thickness of a flange in-line.

[0010]

SUMMARY OF THE INVENTION According to the present invention, there is provided a container having a flange formed of a light-guiding material .
Inject light at a substantially right angle, guide the light through the inside of the wall to the flange end face, cause the flange end face to emit light, measure the light emitting end face with an optical sensor, and image-process the measurement signal to obtain the flange. The above object is achieved by a method for measuring the thickness of a flange of a container made of a light-guiding material, characterized in that the thickness of the flange is obtained.

[0011]

Further, the flange may be measured immediately after trimming by the trimming device when the container is detached from the trimming mold.

According to a second aspect of the present invention, there is provided a positioning means for positioning a container made of a light-guiding material with a flange in an axial direction and a radial direction thereof, and a method for positioning the container with a flange in a state of being positioned by the positioning means. A light source device for injecting light into the light, a light sensor unit for measuring a light emitting portion on the end face of the flange that emits light by the light guided to the flange through the inside of the wall, and an image processing of an output signal of the light sensor unit. A processing device for detecting the thickness of the flange end face.
The flanged container has a circular cross section,
The front is placed opposite the bottom wall of the flanged container.
It is characterized by having a ring-shaped lamp of almost the same shape as the circular shape
The flange thickness measuring device of the light guide material container made shall be the one in which to achieve the above object.

[0014]

The positioning means in the axial direction of the positioning means may be a stopper plate made of a light transmitting material which is in contact with the bottom wall of the flanged container, and the light source device may be opposed to the bottom wall via the stopper plate. The light may be injected into the bottom wall via the stopper plate.

The positioning means may be a container receiving stand for receiving a container with a flange immediately after being detached from the flange trimming device.

Further, the optical sensor may be a television camera.

[0018]

According to the first aspect of the present invention, light injected into the wall surface of the flanged container from the outside is guided to the flange end surface, and the end surface is illuminated. Therefore, by measuring the thickness of the light emitting end face with an optical sensor, it is possible to accurately measure the thickness of the flange end face even if there is a defective setting of the container, the curvature of the flange, etc., further affecting individual differences. Without being
Flange thickness can be measured easily, quickly and accurately, and in-line if necessary.

At this time , since the light is introduced substantially at a right angle from the bottom wall surface of the container with the flange, the light introduced from the wall surface passes through the peripheral wall surface to the tip of the flange easily and efficiently. Since the direction of the light that is guided and cannot enter the bottom wall surface is substantially orthogonal to the flange, it is unlikely to cause noise during measurement.

According to the second aspect , since the measurement is performed immediately after the trimming by the trimming device, the container detached from the trimming mold can be received and positioned as it is, and the measurement accuracy and the measurement efficiency can be improved.

According to the second invention of claim 3, efficiency <br/> flanged container having a circular cross section in a state of being positioned in the axial and radial directions, from the bottom wall of the container in the ring-shaped lamp in its wall
Good light is introduced, guided to the flange end face, the flange end face is illuminated, and the light emitting section is measured by the optical sensor section, and the thickness of the flange end face is detected by image processing, so that the setting of the container is slightly defective. , Flange curvature,
The thickness of the flange can be measured accurately and quickly without being affected by individual differences of the measurers.

[0022]

According to the fourth aspect, it is possible to position the stopper plate made of a light-transmitting material in contact with the bottom wall of the container, and to inject light from the bottom wall side via the stopper plate.

According to the fifth aspect , since the positioning means of the flanged container is a container receiving tray for receiving the container immediately after the flange trimming, the thickness of the flange can be measured using the receiving tray immediately after the trimming. Therefore, there is no need to provide a separate step for measurement and a separate positioning means.

According to the sixth aspect , since the optical sensor is a television camera, a signal suitable for image processing can be obtained easily and accurately.

[0026]

Embodiments of the present invention will be described below with reference to the drawings.

First, an outline of the method for measuring the thickness of a flange of a container made of a light-guiding material according to the present invention will be described with reference to FIG.

For example, if the container 10 to be measured is PET
In the case of a (polyethylene terephthalate) can, it is generally transparent and can guide light into the wall surface 12 thereof.

The bottom wall 14 of the container 10 is connected to the transparent stopper plate 1
6, and the bottom wall 14 is illuminated by a ring-shaped light 18 via the stopper plate 16. Part of the light transmitted through the stopper plate 16 enters the bottom wall 14,
The incident light is reflected by the flange 20
And the end face 20A is caused to emit light.

The end face 20A is photographed from the side by the CCD 22, and the obtained video signal is subjected to image processing by the image processing device 24 to detect the thickness of the light emitting portion. At this time, at the time of image processing, an unnecessary image such as a surrounding image or a background and the flange end face 20A serving as the measurement unit are connected to the flange end face 2A.
Since 0A emits light, it is greatly differentiated, and furthermore, handling and photographing operations are simplified.

Since the image signal does not depend on the background, the rising and falling edges of the obtained image signal, that is, the edges are clear, and the thickness can be measured with high accuracy. Further, since the measurement can be performed continuously, the measurement can be performed in-line, and the measurement at a plurality of locations can be performed simultaneously by the plurality of CCDs.

Next, an embodiment of an apparatus for measuring the thickness of the flange of the PET can in-line in the process of manufacturing the PET can will be described with reference to FIGS.

In this embodiment, a trimming device 2 for trimming a flange 20 of a container 10 which is a PET can is used.
No. 6 is used.

The trimming device 26 is fitted into the inside of the flange 20 of the container 10 and is divided into a male mold 28 for fixing the same and a right and left split mold in the figure. And a female mold 32 for trimming the flange 20 in cooperation with the male mold 28 while restraining the periphery of the flange 20 of the container 10 fitted to the male mold 28 from the outside. . The male mold 28 is driven in the axial direction of the container 10 by the hydraulic cylinder device 34.

In this embodiment, the female mold 32 is opened after the trimming is completed, and the container 10 is received from below while the container 10 is driven in the direction of the bottom wall 14 by the male mold 28, and the bottom wall 14 is positioned. Cradle 34 with stopper plate 16
Is provided.

The receiving table 34 includes a stopper plate 16 as the axial positioning means, and a positioning plate 36 as the radial positioning means for the container 10.

As in the case of FIG. 1, the stopper plate 16 is made of a transparent plate, for example, an acrylic plate, and the ring light 18 is made of a ring-shaped high-frequency fluorescent lamp. Reference numeral 19 in FIG. 2 indicates a lighting device.

CCD 22 for measuring flange 20
Are arranged at substantially equal angular intervals in the circumferential direction of the container 10, and each output signal is taken into the image processing device 24.

The image capturing by the CCD 22 is performed when the trimming is completed and the male mold 28 is retracted from the extruded container 10 to return to the original position. Image processing device 2
4, the signal is output to the operation control sequencer 38, and the command signal from the operation control sequencer 38 causes the container 10 to move to the pedestal by the air blow of the compressed air, as shown in FIG. From 34, it is dropped into a bucket (not shown).

The image processing device 24 binarizes the captured image information to clearly differentiate the image of the light emitting end face 20A from its background image, and calculates the thickness of the light emitting end face 20A. .

At this time, even if the flange 20 is curved, or if the bottom wall 14 contacts the stopper plate 16 obliquely and the setting is poor, the end face 20A is not
If it is within the scanning range of the CD 22, the thickness of the end face can be accurately and reliably measured. In addition, since these use image processing, the measurement time can be reduced and the measurement accuracy can be stabilized.

In the above embodiment, the container 10 is a so-called PET can, but the present invention is not limited to this, and the container 10 may be made of a light-guiding material. Therefore, the present invention is naturally applied to measurement of containers made of other synthetic resins.

[0043]

Further, in the above embodiment, the end face 20A of the flange 20 is measured by a CCD.
Another optical sensor may be used. If necessary, any device that detects the edge of the emitting end surface 20A may be used. For example, sensing may be performed by using a photodiode so as to cross the vicinity of the end surface 20A.

Further, in the above embodiment, the trimming device 26
However, the present invention can be generally applied to a case where the trimming device 26 is not used, for example, a case as shown in FIG.

[Brief description of the drawings]

FIG. 1 is a sectional view including a partial block diagram showing an embodiment of a flange thickness measuring method according to the present invention.

FIG. 2 is a perspective view showing an embodiment of a flange thickness measuring device when the present invention is applied to a flange trimming device.

FIG. 3 is a plan view of the embodiment.

FIG. 4 is a perspective view including a partial block diagram showing a flange thickness measuring means.

FIG. 5 is a perspective view showing a conventional flange thickness measuring method.

FIG. 6 is a plan view showing an image of a flange obtained by the conventional method.

FIG. 7 is a plan view showing an image obtained by the conventional method.

FIG. 8 is a plan view showing another image obtained by the conventional method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Container 12 ... Wall surface 14 ... Bottom wall 16 ... Stopper plate 18 ... Ring light 20 ... Flange 20A ... End surface 22 ... CCD 24 ... Image processing device 26 ... Trimming device 28 ... Male type 32 ... Female type 34 ... Cradle 36 … Positioning plate

Claims (6)

(57) [Claims] 1. Injecting light into a wall surface of a flanged container formed of a light-guiding material at a substantially right angle from the bottom wall surface, guiding the light through the wall surface to a flange end surface, and setting the flange end surface. A method for measuring the thickness of a flange of a container made of a light-guiding material, comprising emitting light, measuring the light-emitting end face with an optical sensor, and processing the measurement signal to obtain an image of the thickness of the flange. Wherein Oite to claim 1, the flange, immediately after trimming by trimming device, the flange thickness measurement method of the light guide material made container, characterized by measuring when the vessel has left the crop type . 3. A positioning means for positioning a light-guiding material-made flanged container in its axial and radial directions, and light is injected into the wall surface of said flanged container positioned by said positioning means. A light source device, an optical sensor unit that measures a light emitting portion of the flange end surface that emits light by light guided to the flange through the inside of the wall surface, and performs image processing on an output signal of the optical sensor unit to perform image processing on the flange end surface. a processing device for detecting a thickness of, Ri na have the flange Tsukeyo
The vessel is circular in cross section, and the light source device
Of the same shape as the circle placed opposite the bottom wall of the vessel
Ring-shaped lamp flange thickness measuring device of the light guide material container made you comprising the. 4. The positioning device according to claim 3 , wherein the axial positioning means of the positioning means is a stopper plate made of a light-transmitting material that contacts a bottom wall of the flanged container, and the light source device is provided with the stopper plate interposed therebetween. Wherein the light is injected into the bottom wall via the stopper plate, and the thickness of the flange of the container made of a light-conductive material is measured. 5. A method according to claim 3 or 4, wherein the positioning means, the flange thickness of the light guide material made container, which is a vessel receiving table for receiving a flanged container immediately detached from the flange trimming device measuring device. 6. In any of the claims 3 to 5, wherein the optical sensor unit is flange thickness measuring device of the light guide material made container, which is a television camera.