JPH0641925B2 - Pinhole inspection device for press-formed products and device for supporting molded products - Google Patents

Description

TECHNICAL FIELD The present invention relates to an inspection device for detecting the presence or absence and the position of a pinhole or the like in a molded product such as an aluminum container formed by press molding, and a supporting device for the molded product. Is.

[Prior Art] Conventionally, an aluminum container formed by press molding has been used as a container for frozen foods requiring air tightness. And since this aluminum container is formed to be extremely thin, when impurities are present in the aluminum plate of the material,
The existing portion becomes a pinhole. Further, since this kind of container is generally subjected to deep drawing during press molding, defects such as product breakage may occur at the corners and the like during molding. Therefore, it is necessary to perform pinhole and damage inspection on all press-formed products.

Conventionally, as a method of inspecting such pinholes, visual inspection by an operator or irradiation of light from a light source (not shown) arranged on one side of the molded product W as shown in FIG. When there is a defect such as a pinhole, the light passing through the defect is detected by a sensor S arranged on the opposite side of the light source L.

[Problems to be Solved by the Invention] However, there is a problem that the visual inspection by the operator has low work efficiency and a high possibility of missing a small pinhole or the like. On the other hand, also in the case of the inspection device in which the sensor S detects the light passing through the defect such as the pinhole generated in the molded product W, the pinhole and the crack generated in the corner portion or the side surface portion of the container formed by deep drawing. However, there is a problem that the detection of the above is uncertain. That is, in the above-mentioned conventional apparatus, since the molded product W is irradiated with light from a direction substantially orthogonal to the bottom wall of the molded product W, the light is substantially parallel to the wall surface with respect to the side wall formed by deep drawing. It has been difficult to give a uniform amount of light to the corner portion where defects are likely to occur from the direction orthogonal to the wall surface.

The present invention has been made in view of the above conventional problems, and a first object thereof is to form a molded product at the time of inspecting a pinhole or the like of a molded product such as an aluminum container which has been deep-drawn by press molding. A second object of the present invention is to provide a molded product supporting device capable of easily and reliably applying a sufficient amount of light to the corners and side wall surfaces of the molded product. The object of the present invention is to provide an inspection device for a pinhole or the like of a press-molded product, which can surely know at which position of the molded product the defect exists.

[Means for Solving the Problems] In order to achieve the first object, in the present invention, the molded product supporting device is formed of a material having good light transmission and diffusivity, and has a shape substantially the same as the outer shape of the press molded product. Is provided with a housing recess. The housing recess does not necessarily need a bottom wall, and the bottom of the housing recess may be open.

Further, an inspection device for achieving the second object is a molded product supporting device having a housing recess formed of a material having a good light transmitting and diffusing property and having substantially the same outer shape as a press molded product, and the supporting device. An irradiation device for irradiating the device with light from the bottom surface side of the molded product housed in the housing recess, a detection device for detecting light passing through the molded product fitted and supported by the support device, and the detection device. A discriminating device for discriminating which position of the molded product the detected light is based on.

[Operation] When a parallel light beam is irradiated to the molded product supporting device from the bottom surface side of the molded product housed in the housing recess while the press molded product is fitted in the housing recess of the molded product supporting device, the molded product supporting device The irradiation light that has reached the point advances through the inside of the molded product support device made of a material with good light transmission and diffusion properties while repeating diffusion and transmission, and goes from the accommodating recess containing the molded product to the outer peripheral surface of the molded product. Arrives with a uniform amount of light. If the molded product has a defect such as a pinhole or a crack, the diffused light that has reached will pass through that part. In other words, even when the molded product is irradiated with light from one direction, the light is irradiated on all surfaces of the molded product with a sufficient amount of light for detecting pinholes, etc. This ensures that a predetermined amount of light reaches the corner portion where it is difficult to detect defects such as pinholes.

Further, in the apparatus according to the second aspect of the present invention, the molded product is fitted and supported by the molded product supporting device by the irradiation device from the bottom surface side of the molded product housed in the housing recess with respect to the supporting device. When the light is irradiated, the light reaching the supporting device propagates through the inside of the supporting device while repeating the diffusion and diffusion, and detects a pinhole or the like on the surface of the accommodation recess, that is, the outer peripheral surface of the molded product. Reach with a sufficient amount of light. Then, when the light reaching the outer peripheral surface of the molded product has a defective portion such as a pinhole, the light passes through the defective portion. The light that has passed through this molded product is detected by a detection device such as a photoelectric sensor, a CCD image sensor, or a television camera, and the light detected by the detection device by a determination device equipped with means for encoding the video signal of the detection device is detected. It is determined which position of the molded product has passed.

Example 1 A first example in which the present invention is embodied in a pinhole inspection device for an aluminum container will be described below with reference to FIGS. As shown in FIG. 2, in the inspection device 1, molded product supporting devices 3 are attached at predetermined intervals in place of the buckets of the known bucket conveyor, and the molded product supporting devices 3 extend in the longitudinal direction along the upper surface of the frame 2. The conveyor device 4 is arranged so as to move. A large number of aluminum containers 5 (shown in FIGS. 1 and 3) as molded products are stacked near one end of the upper surface of the frame 2 and one aluminum container 5 is placed on the molded product support device 3 from below. A container supply device 6 having a known configuration for supplying is provided. An inspection device main body 7 is arranged in front of the moving direction of the conveyor device 4 of the container supply device 6 (on the right side of FIG. 2). Further, in front of the inspection device body 7, there is a set of container accumulating devices 8 of a known structure for sequentially stocking good aluminum containers after the inspection by the inspection device body 7 such as pinholes in a stacked state from below. 4 are arranged along the moving direction. A defective product discharge chute 9 for discharging a defective product of the aluminum container 5 in which a defect such as a pinhole has been detected by the inspection device body 7 is disposed on one side of the frame 2, and below the defective product discharge chute 9. A defective product collection box 10 is arranged in the box. Further, a control device 11, a monitor television 12, and an operation keyboard 13 for controlling the inspection device body 7 and other drive mechanisms are arranged at a position of the frame 2 which does not correspond to the conveyor device 4.

The molded product support device 3 is made of a material having good light transmission and diffusion properties, for example, milky white acrylic resin, glass, etc., and a housing recess 3a having substantially the same shape as the outer shape of the aluminum container 5 is formed at the center of the rectangular parallelepiped. Has been done. Further, an opening 3b for opening the bottom is formed on the bottom surface of the accommodation recess 3a. The molded product supporting device 3 is attached to the conveyor device 4 so that the aluminum container 5 is fitted and supported in the accommodating recess 3a with the accommodating recess 3a facing upward, and moves in this condition along the upper surface of the frame 2. Has been.

As shown in FIG. 3, the inspection device body 7 is fitted to the molded product support device 3 and the irradiation device 14 for irradiating the molded product support device 3 with light from the bottom surface side of the molded product. The camera 15 is provided as a detection device for detecting light passing through the aluminum container 5 supported in combination. Irradiation device 1
No. 4 uses a halogen lamp as a light source,
It is arranged so that its position in the vertical direction can be adjusted by an elevator mechanism (not shown) so that the distance to the molded product support device 3 moving above it can be adjusted. Further, a heat ray cutting filter 16 for preventing heat rays from the halogen lamp from directly irradiating the molded article support device 3 is arranged above the irradiation device 14. Between the passing position of the molded product supporting device 3 and the filter 16, a cylindrical shape is formed so that the reflection surface is on the inner side in order to prevent the amount of light emitted to the molded product supporting device 3 from being affected by external light. Reflector 17
Is fixed to the piston rod 18a of the air cylinder 18 via a bracket 19, and the operation position of the air cylinder 18 causes its upper end surface to come into contact with the lower surface of the molded product supporting device 3 and the lower surface of the molded product supporting device 3. It is arranged to be moved to the retracted position.

On the other hand, the camera 15 has a lens 15a through a support bracket 21 fixed to a support frame 20 having a through hole 20a formed at a predetermined position corresponding to the irradiation device 14 above the conveyor device 4. It is fixed in a state in which the rubber seal member 20b attached to the peripheral edge is inserted to the lower side. On the outside of the support bracket 21, a bellows 23 having a cylindrical hood 22 attached to its lower portion is fixed to the support frame 20 at its upper end in order to eliminate the influence of ambient light when the camera 15 shoots the aluminum container 5. . An air cylinder 24 is fixed to the support frame 20 in a vertically extending state at its base end, and a guide rod 25 is movably supported on the opposite side of the air cylinder 24 across the bellows 23. A support plate 26 having a through hole 26a having a diameter substantially equal to the inner diameter of the hood 22 is horizontally fixed to the tip of the piston rod 24a of the air cylinder 24 and the lower end of the guide rod 25, and the hood is mounted on the upper surface of the support plate 26. The lower end of 22 is fixed. Then, the operation of the air cylinder 24 causes the support plate 26 to move and be arranged in an operating position where it comes into contact with the upper surface of the molded product supporting device 3 and a retracted position where it is separated from the upper surface. Light other than the light passing through the molded product support device 3 does not enter 15. The camera 15 is provided with a wide-angle lens, and its diaphragm adjustment can be remotely adjusted by an diaphragm adjusting device (not shown) provided outside and above the support frame 20.

The control device 11 has a discriminating device 2 for discriminating which position of the aluminum container 5 the light having passed through the aluminum container 5 has passed based on the detection signal of the camera 15, that is, the image.
7 is incorporated. The discriminating device 27 includes a microprocessor (hereinafter abbreviated as MPU) 28, a binarizing circuit 29 for converting an analog video signal of the camera 15 into a binarizing signal,
Image memory 30 for storing images of a binarized signal for a plurality of screens
And a run-length memory 31 for storing the run-length encoded image stored in the image memory 30.
And a memory 32 for temporarily storing the calculation processing result by the MPU 28 and the like. The MPU 28 is connected to a controller 34 via an external interface 33, and the controller 34 is a mechanical drive mechanism for the conveyor device 4, the container supply device 6, the container stacking device 8, the air cylinders 18, 24, etc., based on a command signal from the MPU 28. Drive control. In addition, the monitor TV 12 receives the camera 15 by the control signal of the MPU 28 via the multiplexer 35.
Image signal, the binarized signal of the binarization circuit 29, the image signal of the image memory 30 or the image converted into the character signal with the pinhole or the like as a circle is selectively displayed.

Next, the operation of the device configured as described above will be described. The operation of the inspection device 1 is started with a large number of aluminum containers 5 stocked in the container supply device 6. The conveyor device 4 is intermittently driven by the controller 34 so that the accommodating recess 3a of the molded product support device 3 is sequentially stopped at a predetermined position corresponding to the aluminum container 5 stored in the container supply device 6.
When a certain molded product support device 3 is stopped at a predetermined position corresponding to the container supply device 6, the molded product support device 3 is also arranged at a position corresponding to the inspection device body 7 and the container stacking device 8. There is. The conveyor device 4 is an air cylinder 1.
The 8 and 24 piston rods 18a and 24a are arranged at the retracted position, and the reflector 17 and the hood 22 are driven at a retracted position where they are separated from the molded product supporting device 3. The container container 5 is placed in the accommodation recess 3a by the container supply device 6.
When the molded product support device 3 fitted with is moved to a position corresponding to the camera 15 of the inspection device main body 7, the conveyor device 4 is stopped and the air cylinders 18 and 24 are operated to operate the piston rod 18a. , 24a project. Then, the reflecting plate 17 is arranged at an operating position where it comes into contact with the lower surface of the molded product supporting device 3, and the supporting plate 2
6 is arranged in an operating position where it abuts the upper surface of the molded product support device 3. As a result, the lower surface of the molded product support device 3 is irradiated with a constant amount of light emitted from the irradiation device 14. The hood 2 is located above the molded product support device 3.
The camera 2 is completely sealed by the bellows 2 and the bellows 23, and the camera 15 is in a state in which light other than the light that has passed through the molded product support device 3 and the pinhole of the aluminum container 5 is not incident.

Piston rods 18a, 24 of the air cylinders 18, 24
The video signal from the camera 15 is taken in based on the protrusion operation completion signal of a.

The light emitted from the irradiation device 14 enters the molded product support device 3 from the bottom surface of the molded product support device 3 in a substantially parallel state as shown in FIG. The bottom surface of the aluminum container 5 housed in the housing recess 3 is directly irradiated with light emitted from the irradiation device 14 in a substantially parallel state through the opening 3b. On the other hand, since the molded product support device 3 is formed of a material having good light transmission and diffusion properties, the light incident on the molded product support device 3 at the portions corresponding to the corners and side walls of the aluminum container 5 is transmitted. Since the light propagates while repeatedly diffusing, the light reaches the side wall surface substantially orthogonal to the bottom surface in a direction orthogonal to the wall surface of the accommodation recess 3a with a substantially constant light quantity sufficient for detecting a pinhole or the like. Therefore, the accommodation recess 3a
A sufficient amount of light for detecting a pinhole or the like is emitted from a direction orthogonal to the outer peripheral surface of the aluminum container 5 accommodated in the inside, and even if there is a conventional pinhole or crack, it is not discovered. The light is also radiated from the vertical direction to the difficult corner portion, and the light surely passes through the pinhole and the crack portion to the inside of the aluminum container 5.

The analog video signal from the camera 15 is exchanged into a binary code by the binarization circuit 29 and stored in the image memory 30 as an image. When the analog signal is converted into a binary code, it is converted into 1 when the light amount is equal to or higher than a certain level and 0 when the light amount is less than the certain level. Therefore, when there is no portion corresponding to the signal 1 in the area corresponding to the aluminum container 5 of the image stored in the image memory 30, it means that the aluminum container 5 has no defect such as a pinhole. In that case, M
The PU 28 determines that the aluminum container 5 is a non-defective product, and outputs a restart signal for the conveyor device 4 to the controller 34.

On the other hand, the aluminum container 5 of the image stored in the image memory 30
When the signal 1 is present in the area A1 corresponding to, it is determined that the aluminum container 5 is a defective product having defects such as pinholes that allow the passage of light. When it is determined that the product is defective, it is necessary to determine which area surrounded by the chain line at the position of the image shown in FIG.
U28 performs run-length coding processing on each of the areas A2 to A5 with respect to the image stored in the image memory 30, and stores the result of the run-length coding processing in the run-length memory 31. And MPU28
Is an area A in which a pinhole is generated at a corner portion based on the information stored in the run length memory 31.
2, A3, A4, A5 are discriminated and the area is stored in the memory 32. Areas A2, A3, A4, A5
If there is no pinhole at, it is determined that a pinhole has occurred at a place other than the corner portion.

When the aluminum container 5 with pinholes is detected,
The MPU 28 tells the controller 34 not to operate the container stacking device 8 when the molded product support device 3 supporting the aluminum container 5 moves to a position corresponding to the container stacking device 8 as the conveyor device 4 is driven. Issue a control signal.
Therefore, the container stacking device 8 is operated only when the molded product support device 3 supporting the non-defective aluminum container 5 is moved to a position corresponding to the container stacking device 8, and is accommodated in the accommodation recess 3 a of the molded product support device 3. The supported aluminum container 5 is detached from the molded product supporting device 3 and sequentially stacked in layers from below. After one container stacking device 8 is filled with the aluminum container 5, the other container stacking device 8 is activated, and before the other container stacking device 8 is filled with the aluminum container 5, the operator installs the one container stacking device 8 or the like. The good quality aluminum container 5 is collected from.
Further, the defective aluminum container 5 supported by the molded product supporting device 3 passes through a position corresponding to the container stacking device 8 when the conveyor device 4 is driven, and then is molded when moving around the circling part of the conveyor device 4. The product is discharged from the accommodation recess 3 a of the product support device 3 onto the defective product discharge chute 9 and collected in the defective product collection box 10.

When pinholes or the like occur continuously in the specific area, it is considered that pinholes or the like have occurred due to a specific cause. Workers regularly monitor TV 12
Check if the pinholes are not concentrated in a specific area, and if pinholes are concentrated in a specific area, check the pressing conditions in the previous step, that is, the press forming process of the aluminum container 5. Make a change. If pinholes are continuously generated in areas other than the corners, there will be many defective products in the aluminum plate that is the material of the aluminum container 5, and the area A2 corresponding to the corners will be present.
If defective products having pinholes in A5 are continuously detected, it is determined that the pressing conditions are not appropriate. Therefore, not only the good product and the bad product of the aluminum container 5 are automatically sorted, but also it is possible to examine the suitability of the press condition such as the press process which is the previous process from the information of the location where the pinhole is generated. Become.

Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIGS. This embodiment differs from the previous embodiments in that the lens of the camera 15 can be brought close to the optical axis of light passing through a pinhole or the like generated on the side wall of the aluminum container 5. That is, as shown in FIG.
A fisheye lens was used as the lens, and the camera 15 was fixed such that the lens was arranged in the vicinity of the passing position of the molded product supporting device 3. If the entire aluminum container 5 is to be accommodated in the field of view without using a fisheye lens, it is necessary to dispose the lens at a position away from the aluminum container 5 as shown in FIG. 7 (b). Therefore, the lens becomes far from the optical axis of the light passing through the pinhole generated on the side wall of the aluminum container 5, and the intensity of the light passing through the pinhole reaching the lens becomes weak. However, when a fisheye lens is used as in this embodiment, even if the lens is brought close to the aluminum container 5 as shown in FIG. The lens is close to the optical axis of the light passing through the pinhole, the intensity of the light passing through the pinhole reaching the lens is not weakened, and the detection accuracy is improved.

The present invention is not limited to the above embodiment,
For example, the light passing through the pinhole generated in the bottom wall of the aluminum container 5 is incident on the lens at a right angle, whereas the light passing through the pinhole generated in the side wall of the deep-drawn aluminum container 5 is passed. In order to prevent the detection accuracy of pinholes generated on the side wall from lowering compared to the bottom wall due to insufficient light quantity due to the light being obliquely incident on the lens,
As shown in FIG. 8, inside the aluminum container 5, the light passing through the pinhole generated in the side wall is transmitted through the aluminum container 5 with its optical axis.
The pinhole may be detected by arranging the mirror 36 at a position where the light is reflected so as to be orthogonal to the bottom wall. In this case, if the mirror 36 is placed inside the aluminum container 5, it may be difficult to detect the pinholes on the bottom wall of the aluminum container 5, so it is necessary to perform the photographing by the camera 15 in two steps. That is, first, an image is taken without placing the mirror 36 in the aluminum container 5, and then the mirror 36 is placed in the aluminum container 5.
The picture is taken while it is placed inside. By doing so, the light that has passed through the pinholes generated in the side wall of the aluminum container 5 also enters the detection device at a right angle similarly to the light that has passed through the pinholes in the bottom wall, and the detection accuracy for the side wall is lower. Is equivalent to

In addition, the molded product support device 3 is formed so as to cover the bottom wall of the aluminum container 5 without forming the opening 3b at the bottom of the housing recess 3a, or a milky white acrylic resin is used as the material of the molded product support device 3. In addition to glass and the like, a transparent resin formed so that the bending rate is sequentially changed inside is used so that a light beam that enters from the bottom surface of the molded article supporting device 3 substantially in parallel travels toward the peripheral surface of the housing recess 3a. Alternatively, instead of the camera 15, a photoelectric sensor, a CCD image sensor or the like may be used as a detection device. When a shortage of light amount for pinhole detection is expected, the detection accuracy can be improved by using a CCD camera equipped with a function capable of long-time exposure (for example, a slow speed shutter) as a detection device. . Moreover, in order to enable parallel inspection of a plurality of types of aluminum containers 5 having different sizes, the conveyor device 4 is provided with a housing recess 3
The molded product supporting devices 3 having different sizes of a are attached in parallel, the same number of cameras 15 as the types of the aluminum containers 5 are provided, and the signal from the camera is binarized through the multiplexer 29.
And so on. It may also be used for inspection of opaque molded products other than the aluminum container 5.

[Effects of the Invention] As described in detail above, according to the present invention, a sufficient amount of light for detecting a pinhole or the like is substantially orthogonal to the outer surface of the outer surface of a press-formed product that has been deep-drawn by press forming. Since the irradiation can be easily performed from the direction in which the pinholes are detected, the pinholes can be surely found even in a portion such as a corner portion where it was difficult to conventionally find the pinholes. Further, in the invention described in the second aspect, it is possible to determine at which position of the molded product the defect such as the pinhole occurs. Therefore, when the defect such as the pinhole continuously occurs at a specific position, based on the information. As a result, it is possible to easily find out the cause of defective products.

[Brief description of drawings]

1 to 5 show a first embodiment embodying the present invention. FIG. 1 is a sectional view of a molded article supporting device 3, FIG. 2 is a schematic side view of the entire inspection device, and FIG. FIG. 4 is a cross-sectional view of the main part of the inspection apparatus body, FIG. 4 is a block diagram, FIG. 5 is a view showing the visual field of the camera and the positional relationship of an aluminum container as a molded product,
FIGS. 6 and 7 show the second embodiment, FIG. 6 is a sectional view of an essential part, FIG. 7 (a) is a schematic view showing the action, and FIG. 7 (b) is without a fisheye lens. FIG. 8 is a schematic diagram showing the action in the case, FIG. 8 is a schematic diagram showing the action of the modified example, and FIG. 9 is a schematic diagram of the conventional method. Molded product support device 3, housing recess 3a, opening 3b, aluminum container 5 as molded product, inspection device body 7, irradiation device 1
4, camera 15 as detection device, discrimination device 27, binarization circuit 29, image memory 30, run length memory 3
1, areas A1 to A5.

Claims (2)

[Claims] 1. An accommodating recess (3) formed of a material having good light transmission and diffusion properties and having substantially the same outer shape as a press-formed product.
A molded product supporting device for inspecting pinholes and the like of a press molded product, characterized in that a) is provided. 2. An accommodating recess (3) formed of a material having good light transmission and diffusion properties and having substantially the same shape as the outer shape of the press-formed product.
a) a molded product supporting device (3), an irradiation device (14) for irradiating the supporting device (3) with light from the bottom side of the molded product housed in the housing recess (3a), A detection device (15) for detecting light passing through the molded product (5) fitted and supported by the support device (3), and the detection device (1)
A pinhole for a press-formed product, comprising: a determination device (27) for determining which position of the molded product (5) the light detected based on the detection signal of 5) has passed through. Etc. Inspection device.