JPS6239746A - Apparatus for inspecting external appearance of cylinder - Google Patents

Abstract

PURPOSE:To make it possible to continuously and automatically collect the developed image of a cylindrical surface, by continuously feeding a plurality of cylindrical objects to be inspected to the direction at a right angle to the center axis of each object while respectively rotating them to the same direction. CONSTITUTION:The titled apparatus is equipped with a feed part 1 for continuously feeding a plurality of cylindrical object P1-P5 to be inspected to the direction at a right angle to the center axis of each object while said objects P1-P5 are respectively rotated to the same direction, an image pickup part 11 arranged above said feed part 1 and equipped with an area sensor 10 for picking up the image of each of the objects P1-P5 to be inspected and an image control circuit. The images of a plurality of the objects P1-P5 to be inspected continuously fed under rotation are picked up from above by the sensor 10 of the image pickup part 11 and the unidimensional picture element signal corresponding to the central part of each of the objects P1-P5 to be inspected is selectively read from the image pickup sensor 10 in an image control circuit. Said signal is written in an image memory in a stacked form to continuously collect the developed image of the cylindrical surface of each of the objects P1-P5 to be inspected.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention automatically detects the appearance of a cylindrical inspection object with a circular cross section, such as a nuclear fuel pellet used in a fuel rod for power generation. The present invention relates to an apparatus for inspecting the appearance of a cylindrical body.

[Conventional technology]

Conventionally, for example, the visual inspection of cylindrical nuclear fuel pellets (hereinafter referred to as pellets) has been carried out by a method in which the inspection L1 individually grasps the pellets with a bin set and visually inspects them, or by an optical method using laser scanning and line sensors. There are methods such as inspection using an automatic visual inspection device such as Among these, a characteristic feature is that while moving the camera, the cylindrical surface (side)
(Japanese Unexamined Patent Publication No. 55-162178, No. 56-16849), a device for inspecting the end face of pellets (Japanese Unexamined Patent Publication No. 55-154442), A method for inspecting a cylindrical surface (Japanese Unexamined Patent Publication No. 160645/1983) is mentioned.

[Problem that the invention seeks to solve]

By the way, the above-mentioned visual inspection method has low work efficiency because it is a sensory inspection by humans, and when working for a long time, it is difficult to maintain a constant inspection level due to fatigue etc. There has been a desire to develop a visual inspection device that can automatically perform visual inspections in order to prevent exposure to radiation.

However, each of the conventional visual inspection apparatuses described above has the following problems.

That is, in a device that inspects the side surface while moving the camera, there are problems with the reproducibility, stability, and durability of the device, and there is also a speed limit. In addition, when detecting with a laser or one-dimensional sensor while rotating and transporting multiple pellets in the axial direction, the cylindrical surface to be inspected moves in the axial direction with rotation, so the boundaries of the pellets are unclear. This causes problems such as lower inspection reliability and the inability to simultaneously inspect the end face. In addition, JP-A-5
The end face inspection apparatus described in Japanese Patent No. 5-154442 has a problem in that it cannot simultaneously inspect the cylindrical surface due to its structure.

Furthermore, in the method described in JP-A-56-160645, in which a cylindrical surface is inspected while rotating a pellet on a roller, the detector is an image sensor that detects point or line images. - Therefore, it is necessary to stop the conveyance of the pellet for each inspection, inspect the entire circumference, and then carry out intermittent conveyance.However, since the pellets are ceramic, they are easily broken and it is difficult to convey the pellets at high speed. Unless the transport and rotation mechanisms of the pellets are of high performance, the pellets will be damaged (chips, cracks, etc.) and will require intermittent transport and changes in direction and posture, making high-speed inspection difficult.

The present invention has been made in view of the above circumstances, and its purpose is to be able to continuously and automatically collect developed images of a cylindrical surface, and to quickly and reliably inspect an object to be inspected. An object of the present invention is to provide a compact cylindrical body appearance inspection device.

[Means for solving problems]

In order to achieve the above object, the present invention provides a transport section that continuously transports a plurality of cylindrical test objects in a direction perpendicular to their central axis while rotating them in the same direction; Select the wL@ section which is disposed above the section and is equipped with an area sensor that images each of the test objects, and the one-dimensional pixel signal corresponding to the center of each test object from the area sensor of this filled section. The image control circuit is provided with an image control circuit that sequentially reads developed images of the cylindrical surface of each test object by reading them out and writing them into the image memory of each test object in a stacked manner.

[Effect]

In the cylindrical body external appearance inspection apparatus of the present invention, in the conveyance section, each inspection object is imaged from above by the area sensor of the imaging section, which is continuously conveyed while rotating; The image control circuit selectively reads out the one-dimensional pixel values corresponding to the center of each inspection object from the image-carrying area sensor and writes them into the image memory in a stacked manner to create a continuous developed image of the cylindrical surface of each inspection object. Collect information.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on FIGS. 1 to 6.

FIG. 1 is a diagram showing the overall configuration of an embodiment of the present invention.

In this figure, reference numeral 1 denotes a conveying section of vents 1 to P. In this conveying section 1, a plurality of rollers 4 are used to convey pellets P from a pellet supply section 2 to a pellet discharging section 3 while rotating them. Each of the rollers 4 is formed into an endless shape (elliptic shape) by a chain 5 rotatably connected to both end surfaces thereof, and between the both end surfaces of these rollers 4 and the chain 5, the axis of each roller 4 is As shown in FIG. 2, a gear 6 mounted on each roller 4
It is meshed with a rack 8 fixed to a fixing belt 7 below. Then, by a drive device (not shown),
In FIG. 2, when the chain 5 is moved to the left, each roller 4 is moved to the left.
The gear 6 meshing with the rack 8 of the fixed belt 7 is reversed counterclockwise to rotate the roller 4 counterclockwise. In addition, above the middle part of the conveying section 1 where the rotation of the bevels 1-P placed on each roller 4 is stabilized, there is a cylindrical image-like structure having a lens 9, an area sensor 10, and a high-speed shutter. (Imaging unit) 11 aligns the horizontal scanning direction of the area sensor 10 with the axial direction of the pellet P, and a plurality of (three in the case of J3 in this embodiment)
are arranged so as to simultaneously image the cylindrical surface of the pellet P.

A pair of end face imagers 12 are disposed outside both end faces of the pellet P imaged by this cylindrical surface IEi imager 11, respectively, to take images of each end face. Further, in the vicinity of one end-face imager 12, three detectors 13 for detecting the position of the pellets P are installed in parallel in the transport direction of the pellets P. , one detector 13 is disposed in the pellet sorting section 14 of the pellet discharging section 3, and when this detector 13 detects passage of rejected pellets P, the nrg1 mechanism 14a of the pellet sorting section 14 is activated. is opened, and the pellet P falls downward.

The detection signals of each of the above-mentioned detectors 13 are transmitted to the command controller 1
Based on this signal 0, the instruction controller 15 controls each of the image pickup devices 11 and 12 in synchronization with the position of the pellet P to obtain a developed image of the cylindrical surface of the pellet P and both end surfaces. The image is now obtained. - The electric circuit section for obtaining a developed image of the cylindrical surface of the pellet P will be explained based on FIG. The command control circuit 16 outputs a command signal to the area sensor 10 of the cylindrical image pickup device 11 and the cylindrical image control circuit 17 based on the detection signal. As the area sensor 10, for example, a 512×512 area sensor is used that can read out scanning pixels at three locations by specifying an address.

Further, the cylindrical surface image control circuit 17 controls three pellets P+,
Each horizontal scanning image sensor stack P of the area sensor 10 corresponds to the image P2, P3 axis PI', P2'IP3'
Only S+, PS2, PS3 are activated, and via the AD converter 18, the storage units M1, M2, . M3. This is something to write in... The developed image of the cylindrical surface written in each of the storage units M1 to M5 of the image memory 19 is subjected to image preprocessing as needed, and is monitored by the image switching circuit 20 on the image monitor 21 at the appropriate time. , and is also sent to the cylindrical surface determination circuit 22. As shown in FIG. 4, this cylindrical surface determination circuit 22 extracts a defect image 24 and a crack image 25 from a cylindrical surface developed image 23, and compares them with inspection standards to determine whether the pellet P is acceptable or not. By inputting this result to the command control circuit 16, the command control circuit 16 controls the pellet sorting section 14.

In addition, the processing of the edge image and the fully developed image is also available! To briefly explain the system based on FIG. 5, the end face imaging Ia12 controlled by the command controller 15 images both end faces of the pellet P in accordance with the synchronization signal of the command control circuit 16, and this transport The blurred end face image is written into the end face image memory 26.

, and the end-face image and cylindrical surface-extended lriIiiiMi image of the end-face image memory 26 and the image memory 19 for cylindrical surface are sent to the fully developed image memory 27, and the ZEN-NOH Wr.
In the J image memory 27, as shown in FIG. 6, a developed image 28 is synthesized. The fully developed image 28 and the end image are the top &! Both image cutting circuit 20
The images are inputted into the image monitor 21 and monitored on the image monitor 21, and are also sent to the fully developed image judgment circuit 29 and the end face 1irrs judgment circuit 30, respectively. As shown in FIG. 6, the fully developed image judgment circuit 29 extracts the edge defect 31 from the fully developed image 28 and compares it with the inspection standard to determine whether the pellet P is acceptable or not. The end face image determination circuit 30
Defects such as chips and cracks are extracted from the image and compared with inspection standards to determine whether the pellet P is acceptable or not. The selection signals from these determination circuits 29 and 30 are sent to the command controller 15.

Next, the operation of the cylindrical surface appearance inspection apparatus configured as described above will be explained.

First, as shown in Figures 1 and 2, Beret P+,
P2, Pg, . . . are moved in the horizontal direction by rotating them with rollers 4 and conveying the chain 5 that supports the rollers 4.

In this case, for example, the transport speed of a nuclear fuel pellet with a diameter of 9 barrels and a length of 15 mIN is 30 rrm/s1! e, and the rotational speed of the pellet P is set so that the pellet P rotates once while being conveyed 30 times. Then, the image P of each pellet P+, P2, Pg is sent to the area sensor 10 through the lens 9 through the 3i pellets P+, P2, Pg.
+ ' + P 2. ``lP3' is created and transported.

This imaging operation is performed for each pellet PI, P2, Pg
.

Corresponding to the position of..., the command control circuit 16
The cylinder surface ratio @machine 11 is controlled and repeated, but at this time, each pellet P+, P2, Pg,... is rotating and moving, so the cylinder is rotated from the previously imaged position. The surfaces are imaged sequentially.

Next, the command control circuit 16 gives a command to the cylindrical surface image control circuit 17 based on the detection signal of the detector 13 that detects the position of each of the above-mentioned pellets P+, P2, Pg, and the image P1' of each of the pellets P+, P2, Pg is .

Area sensor 10 corresponding to the central axis of p2r and p3r
Each horizontal scanning layer image element stack PS+, Pg2, P
Activate g3. Then, the cylindrical surface image control circuit 17 controls the image P+'* of each pellet P+, P2, Pg.
A horizontal scanning image sensor stack PS+ of the area sensor 10 corresponding to the central axis of P2'lP3',
The pixel data in the horizontal direction is selectively read out from Pg2 and Pg3, digitized by the AD converter 18, and stored in the X-direction memory of each storage section M1 to M5 of the image memory 19 corresponding to each pellet P+, P2, and Pg. Write in a one-dimensional arrangement so that they are stacked in the Y direction.

Subsequently, after each of the pellets P+, P2, Pg is moved and rotated a certain distance by the roller 4 of the conveying section 1, the images P+', P2' of each pellet P+, P2, Pg are transferred again.
, central ITI of P3'! Area sensor 1 corresponding to l
0 horizontal imager stack PS+, Pg2.

Only Pg3 is activated by the cylindrical screen image control circuit 17, and each of the pellets P+, P2, and Pg is conveyed by the cylindrical surface conveyor @tsuki 11. The cylindrical screen image control circuit 17 then generates images P+', Pz' of the respective pellets P+, P2, and Pg.

Horizontal pixel data is selectively read out from the horizontal image carrying element stack PS+, Pg2, Pg3 of the area sensor 10 corresponding to the central axis of P3', and the AD converter 18
The images are digitized and written in a stacked manner in each storage section M1 to M5 of the image memory 19 corresponding to each pellet P+, P2, and Pg.

By repeating these operations, as shown in FIG.
3 are recorded sequentially. These cylindrical surface development images 23 are
Pre-processing of the image is performed as needed, and the image is monitored by the image switching circuit 20 on the image monitor 21, and
The cylindrical surface determination circuit 22 determines whether each pellet P+, P2
*Pg*... is missing in image 241, cracked image 25 is extracted, and compared with the inspection standard, Beret P+, P2, P
The pass/fail of g, . . . is determined. Then, this determination result is sent to the command control circuit 16, and the command control circuit 16 synchronizes with the conveyance of the pellets P to the pellet sorting section 14.
When the pellet P is rejected, the opening/closing mechanism 14a is opened and the rejected pellet P is dropped.

Also, Beret P+, P2, Pg, P4, Ps
... are continuously and sequentially rotated Wi, and these pellets P+, P2 . 'P3. By sequentially processing Pa, Ps, . . . as an i-image, cylindrical surface development, and determination, the external appearance of the cylindrical surface of the pellet is continuously and automatically inspected. Then, each of the pellets P+, P2 . P3. The cylindrical surface developed image 23 of the pellet P that is rotated and conveyed next is sequentially written in each storage section M1 to M5 of the image memory 19 in which the cylindrical surface developed image 23 of "." is written. The image memory 19 can process continuous visual inspections.

In parallel with the cylindrical surface determination process, each pellet P (P+) is determined by a synchronization signal from the command control circuit 16.

Both end faces of P2 * Pg *...) are end face imagers 12
The end face images are captured by the end face image determination circuit 3.
0, and this result is sent to the command controller 1.
Sent to 5. Then, the command controller 15 outputs a command signal to the pellet sorting section 14 based on the above determination result, and selects the rejected pellets P from the IFiI13#.
By opening the IIi structure 14a, it is dropped downward.

At the same time, among the external defects of the pellet P, regarding the defect 31 on the right side of the pellet cylindrical end and the defect 31 on the end of the pellet end face, the entire developed image is a combination of the cylindrical surface developed image 23 and the end face image. 28, and based on this fully developed image 28, the fully developed image determination circuit 29:
These end defects 31 are extracted, inspected, and compared with standards to determine whether the pellet P is acceptable or not. Then, based on this result, the instruction controller 15 selects the pellet selector 14.
The pellets P are sorted by sending a sorting signal to.

As described above, a fully automatic visual inspection of the pellet P is carried out. In this case, the pellet P is continuously rotated and conveyed in a direction perpendicular to its axis, while the selectively activated area sensor Fj -10 simultaneously images a plurality of pellets P, and writes only the central pixels of the images of these pellets P into each storage section M1 to M5 of the image memory 19 corresponding to each pellet P in a stacked manner. By doing this, it is possible to obtain a developed 1ihi image of the cylindrical surface, and therefore, even though the pellets P are moved at a relatively low rotation speed and slow conveyance speed, it is possible to continuously inspect multiple pellets at once, and the processing Not only can efficiency be improved, but automation can be performed using a compact inspection device. For example, when performing an automatic visual inspection of 3 pellets P per second, by transporting the pellets P 3 cm per second and rotating them once per second, inspection can be performed with a resolution of 0.06 #ll11, and the transport of the pellets P becomes possible. can reduce troubles in

In addition, by recording new image data in the image memory after analyzing the developed image of the pellet P, it is possible to improve the usage efficiency of the image memory, and to perform continuous visual inspection of the pellet P using the limited image memory. It can be processed with Furthermore, together with the developed image of the cylindrical surface of the pellet P, images of both end faces are captured and the two are combined to create a fully developed image to determine whether the appearance is acceptable or not. It is easy to inspect defects in the parts (ends), and the reliability of appearance inspection is greatly improved. Furthermore, a cylindrical surface development image, both end surface images, and a fully developed image of the pellet P are created respectively, and unique inspection criteria are set for each image to determine whether the pellet P is acceptable or not. Since the pellets are sorted, the appearance of the pellets can be quickly and reliably inspected, and the pellets P can be sorted smoothly.

〔Effect of the invention〕

As explained above, according to the present invention, there is provided a transport section that continuously transports a plurality of cylindrical test objects in a direction perpendicular to their central axes while rotating them in the same direction; An R image section that is arranged above the transport section and is equipped with an area sensor that takes a B image of each of the inspection objects, and a central part of each inspection object from the area sensor of this imaging section ← selects the corresponding one-dimensional pixel signal. Since the image control circuit is equipped with an image control circuit that reads out the images and writes them into the image memory of each inspection object in a stacked manner to continuously collect developed images of the cylindrical surface of each inspection object, it can be continuously conveyed while rotating. The area sensor of the imaging unit images each of the multiple test objects from above, and the image control circuit selects a temporary original pixel signal corresponding to the center of each test object from the area sensor that has taken the second image. It is possible to continuously and automatically collect developed images of the cylindrical surface of each inspection object by reading them out and storing them in a stack in the image memory, and also to quickly and reliably inspect the inspection object, which improves inspection efficiency. It has an excellent effect of being able to achieve significant improvements.

[Brief explanation of drawings]

1 to 6 show an embodiment of the present invention,
Figure 1 is a schematic FA view showing the overall configuration, Figure 2 is a side view showing the configuration of the pellet conveying section and the cylindrical surface imager, and Figure 3
Fig. 4 is a block diagram showing the signal processing and control configuration of the pellet cylindrical surface development image system, Fig. 4 is an explanatory diagram illustrating an example of generating a pellet cylindrical surface development image, and Fig. 5 is a block diagram showing the structure of the pellet cylindrical surface development image system. FIG. 6 is a block diagram showing the structure of signal processing and control, and is an explanatory diagram illustrating an example of generation of Bent 1 to full developed images. 1... Conveyance section, 10... Area sensor-111... Cylindrical surface conveyance image division (bν image section), 17
... Cylindrical surface image control circuit, 19 ... Image memory, 23 ... Cylindrical surface image, P, P
+~P5...Bellet (tested object), PS+
, PS2, PS3...Horizontal scanning image sensor stack. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] a conveyance section that continuously conveys a plurality of cylindrical inspection bodies in a direction perpendicular to their central axis while rotating them in the same direction; an imaging unit equipped with an area sensor for imaging;
One-dimensional pixel signals corresponding to the center of each object to be inspected are selectively read out from the area sensor of this imaging unit, and written in a stack to the image memory of each object to be inspected, resulting in continuous developed images of the cylindrical surface of each object to be inspected. 1. A cylindrical body external appearance inspection device characterized by comprising an image control circuit for collecting images.