JPH0345175Y2 - - Google Patents

Description

[Detailed description of the invention] "Industrial Application Field" The present invention relates to an appearance inspection device for inspecting the appearance of a rotating body-shaped object to be inspected, such as a cylindrical body or a cylindrical body, such as nuclear fuel pellets for a nuclear reactor. .

``Prior art'' For example, nuclear fuel pellets for light water-cooled nuclear reactors are produced by molding low-enrichment uranium dioxide powder in a mold to form cylindrical green pellets (also called compacts). Green pellets are sintered at high temperatures to produce dense sintered pellets, and the outer diameter of the sintered pellets is polished to improve dimensional accuracy, which is used as nuclear fuel pellets by filling them into fuel cladding tubes. This nuclear fuel pellet has an outer diameter of 9 mm to 13 mm.
It is a cylindrical body with a length of 5 mm to 15 mm.

If these nuclear fuel pellets have defects such as cracks or chips on their outer surface, the gap between the pellet surface and the cladding tube will be larger in the defective area than in other areas, resulting in poorer heat transfer than in other areas. , the uncertainty of the pellet center temperature increases. Also, cracks,
There is a difference in power distribution between parts with many chips and parts without, which may have a negative impact on reactor performance, or the reactor power may not be able to reach its maximum level. For this reason, the quality of nuclear fuel pellets is guaranteed by visually inspecting all nuclear fuel pellets before use. Conventionally, this visual inspection method is
(1) A method in which nuclear fuel pellets are placed on a tray and transported onto an inspection table, and each nuclear fuel pellet is picked up one by one with tweezers and visually inspected (batch inspection). (2) Nuclear fuel pellets are directly inspected. Alternatively, the nuclear fuel pellets are picked up one by one with tweezers or the like while being placed on a conveyor via a tray in an upright or lying position, and visually inspected on all the nuclear fuel pellets. , a large number of grooves with arcuate bottoms are provided,
Nuclear fuel pellets are lined up in this groove in a lying position, the tray is vibrated by a vibrator, and while the nuclear fuel pellets are rotated by the vibrations, the outer peripheral surface of each nuclear fuel pellet is visually inspected, and if necessary, the nuclear fuel pellets are removed. A method is used in which each piece is picked up with tweezers and all end faces are inspected.

However, in the conventional visual inspection method described above, from the viewpoint of protecting the hands from local radiation exposure, it is necessary to wear radiation shielding gloves that significantly impair work efficiency.
In addition, in (1) above, it takes a lot of time for inspection, is extremely inefficient, is difficult to inspect, and places a heavy burden on the operator. In addition, in (2) above, although the inspection speed is slightly improved, it is not sufficient, and inspection is still difficult, and the burden on the operator is still large. Furthermore, in (3) above, although the inspection speed is further improved, the equipment is insufficient, such as the fact that the nuclear fuel pellets on the tray do not rotate evenly with just the vibration of the vibrator, resulting in eye strain and hand fatigue for workers. There were problems such as the inability to avoid inspection errors such as uneven inspection.

Therefore, in order to solve the above-mentioned problems, the present applicant developed a new appearance inspection device for inspected objects (Japanese Patent Laid-Open No. 57
−93238) was proposed. As shown in FIGS. 14 to 16, this visual inspection device includes a base 1,
At least a pair of rollers 2 rotatably disposed above the base 1 in the same direction; a rotation drive mechanism 3 for rotating the pair of rollers 2 in the same direction at the same speed; A tray 4 is provided on the extension line side so as to be located at approximately the same height as the upper surface of the roller 2, and has one side open on the roller 2 side, and a rotating body-shaped cover placed on the tray 4. It is comprised of a transfer mechanism 5 that transfers the inspection object from one of the tray 4 and the roller 2 to the other, and a mask mechanism 6 that divides and limits the field of view. In this visual inspection apparatus, a rotating body-shaped cover is placed on a tray provided on one side of the rollers 2 on a plurality of rollers 2 above the base 1 that rotate in the same direction. By transporting the inspection object by the transfer mechanism 5, it is possible to reliably rotate a large number of rotating body-shaped inspection objects simultaneously on the roller 2 in a predetermined direction at a predetermined speed, and to limit the field of view. The mask mechanism 6, which can shield areas other than the visual field and move the visual field, can reduce eye fatigue for workers, and reduce local radiation exposure to hands to approximately one-tenth of conventional methods. Mechanism 6
Since the field of view can be limited by the Since there is no uneven rotation of the inspection object, inspection errors such as uneven inspection can be eliminated. In addition, since the objects to be inspected on the tray 4 are once transferred onto the rollers 2, residual debris (chips) between the objects to be inspected or on the tray 4 can be reliably separated and removed, and furthermore, the objects to be inspected can be protected from impact. Since it can be rotated without causing damage, it exhibits excellent effects such as not damaging the object to be inspected.

"Problems to be solved by the invention" However, in the above-mentioned apparatus for inspecting the appearance of objects to be inspected, the object to be inspected P is tilted due to the difference in level between the tray 4 and the transfer table 7 in the pellet transfer section. Depending on the situation, the object to be inspected may not be transferred between the tray 4 and the rollers 2, such as being pushed out or being caught at the joint between the transfer table 7 and the rollers 2. There were times when things didn't go smoothly.

This invention was made in view of the above circumstances,
The purpose of this is an appearance inspection device for inspected objects that can transfer objects to be inspected extremely smoothly between the tray and rollers, and that can reliably prevent objects to be inspected from getting caught in the transfer area. Our goal is to provide the following.

"Means for Solving the Problem" In order to achieve the above object, the present invention provides a tray for placing an object to be inspected, which can be freely moved toward and away from one end of a plurality of rotatably provided rollers. installed in
Further, each roller is provided with a roller moving mechanism for bringing one end of each roller into contact with the tray or separating it from the tray.

"Operation" In the appearance inspection device of the inspected object of the present invention,
When transferring an object to be inspected between a tray and a roller, one end of the roller is brought into contact with the tray by the roller moving mechanism, and the object to be inspected is transferred directly from the tray to the roller or from the roller to the tray. At the same time, when inspecting an object to be inspected, one end of the roller is separated from the tray by a roller moving mechanism to allow the roller to rotate smoothly.

"Embodiment" Hereinafter, an embodiment of the present invention will be described based on FIGS. 1 to 13. This embodiment is an improvement on each part of the conventional example shown in FIGS. 14 to 16.

The appearance inspection device of the present invention includes a plurality of rollers 12 supported by a pair of roller supports 10 and 11 arranged parallel to each other with both ends rotatably facing in the same direction, and each roller 12. A roller rotation drive mechanism 13 that rotates in the same direction and at the same speed.
and a tray 14 for placing the object to be inspected (nuclear fuel pellet) P, which is placed at one end of the roller 12;
A pellet transfer mechanism 15 for transferring the object to be inspected P between the roller 12 and the tray 14, and a roller movement mechanism 16 for bringing one end of the roller 12 into contact with the tray 14 or separating it from the tray 14. The basic configuration is as follows.

As shown in FIGS. 1 to 4, one end of the plurality of rollers 12 is rotatably mounted on a bearing 18 that is removably fitted into an arcuate groove 17 formed on the upper surface of the roller support 10. Supported.
As shown in FIG. 6, the other end of each roller 12 has a semicircular shape formed on the lower and upper surfaces of two half-shaft support members 19 and 20 that can be divided into upper and lower parts of the roller support body 11. It is rotatably supported by a bearing 24 held between grooves 21 and 22 by a plurality of set bolts 23. In addition, each roller 12
A roller gear 25 is fixed to each of the other ends by a nut 25a, and each of these roller gears 25 is connected to a pair of drive gears 27 via an idle gear 26. These driving gears 27 are connected to a torque tender 28.
is connected to a pair of motors 29 via
By operating these motors 29, the torque tender 28, drive gear 27, and idle gear 2
6. Through the roller gear 25, the rollers 12 are interlocked and rotated simultaneously in the same direction and at the same speed. The roller rotation drive mechanism 13 is comprised of these gears 25, 26, 27, a torque tender 28, and a motor 29.

The tray 14, which is partially overlapped on top of one end of the roller 12, has edge plates 31 on both side edges of the corrugated plate 30, and an end plate (on the end farthest from the roller 12). Stoppa) 32 is,
each installed. Further, legs 33 having a substantially V-shaped cross section are attached to the lower surface of each edge plate 31 so as to face tray guides 35 and 36 attached to predetermined positions on the tray loading table 34. Tray holding claws 37 for fixing the tray 14 are provided at a plurality of positions (four positions in this embodiment) on the tray loading table 34. Also,
As shown in FIG. 7, the tray loading table 34 is rotated by a tray rotation motor 38, and a tray is provided at the lower right end of the tray loading table 34 for storing the chips on the tray 14. A chip receiving box 39 is arranged.

The pellet transfer mechanism 15 is operated via a linear motion bearing 40 along a pair of guide bars (not shown) arranged parallel to each other on one side of the roller 12 and the tray loading platform 34, as shown in FIG. , a pair of left and right pellet feeding supports 41, 4
2 is provided so as to be slidable left and right. These pellet feeding supports 41 and 42 are connected to the connecting member 4.
3, and each pellet feed support 41, 42 has a pair of connecting plates 4.
4 are each attached in a hanging shape. In FIG. 7, a claw holding arm 45 is located at the bottom of the left side connecting plate 44 in a non-rotatable state, and a claw holding arm 46 is located at the bottom of the right side connecting plate 44 in a rotatable state. installed. As shown in FIGS. 9 and 10, these claw holding arms 45 and 46 each have a plurality of claw holding rings 48 (for example, 25 pieces) attached around a claw support shaft 47, and a plurality of claw holding rings 48 are attached to each claw. Claws 49 are attached to the retaining ring 48 by welding in a row. In addition, in the insertion hole 50 formed in each claw retaining ring 48, a slip pin 52 which is fitted into a groove 51 formed in the axial direction of the claw support shaft 47 during normal operation, and a slip pin 52 inserted into the slot Retaining ring 48 (claw support shaft 47)
A spring 53 biasing in the direction of the central axis is inserted and attached by a spring force adjustment screw 54. Then, as described above, the claw holding arm 4
The claw support shaft 47 of No. 5 is fixed to the connecting plate 44 and is connected to the claw support shaft 4 of the claw holding arm 46.
7 is rotatably supported by the connecting plate 44 and rotated by a rotation mechanism 55.

The roller moving mechanism 16 is installed below one end of the roller 12, and includes a roller push-up fitting 56 for pushing up the roller 12, and a roller push-up stand 57 that supports the roller push-up fitting 56 in a vertically movable manner. , a spring 58 provided between the roller pushing up metal fitting 56 and the roller pushing up base 57, and a cylinder device 60 having a piston rod 59 connected to the roller pushing up base 57. Furthermore, an arcuate groove 61 is formed on the upper surface of the rotary roller push-up fitting 56 in order to support one end of the roller 12 so as to correspond to the installation location of each roller 12, and the curvature of the groove 61 is The radius is set larger than the radius of curvature of one end (supporting part) of the roller 12, as shown in FIG. Furthermore, one end of the roller 12 and the tray 1
In the vicinity of the contact portion with 4, the roller 12 has:
A tapered surface 62 is formed.

Although not shown, a mask mechanism having the same configuration as the conventional mask mechanism 6 shown in FIG. 16 is provided.

Next, the operation of the visual inspection apparatus configured as described above will be explained.

When inspecting the outer surface of the nuclear fuel pellets P for cracks, chips, etc., first, the tray 14 containing a large number of nuclear fuel pellets P in the valleys of the corrugated plate 30 of the tray 14 in the direction of the valley bottom line is The axial direction of the roller 12 is aligned with the axial direction of the nuclear fuel pellet P on the tray loading table 34, and the roller 1 is
After placing a portion of the tray 14 on one end of the tray 2, the tray 14 is fixed on the tray stacking table 34 by the tray holding claw 37. In this case, by raising the piston rod 59 of the cylinder device 60 of the roller moving mechanism 16,
As shown in FIGS. 1 and 2, the corrugated plate 30 of the tray 14 is in contact with one end of the roller 12, and a groove 61 formed in the roller push-up fitting 56 of the roller moving mechanism 16 By setting the radius of curvature of the roller 12 to be larger than the radius of curvature of one end (supporting part) of the roller 12,
Even if there is a slight deviation in the horizontal direction between one end of the roller 12 and the corrugated plate 30 of the tray 14, it is smoothly absorbed and the one end of the roller 12 and the corrugated plate 30 are firmly attached. Therefore, the level difference between the tray 14 and one end of the roller 12 can be minimized.

In this state, as shown in FIG. 11, the claw holding arm 46 is positioned above the end plate 32 side end of the tray 14 fixed on the tray loading platform 34, and the rotation mechanism 55 is activated. , with the claw holding arm 46 centered on its axis,
Rotate counterclockwise as shown in the figure. and,
Each claw 49 of the claw holding arm 46 pushes out a large number of nuclear fuel pellets P placed on the tray 14 toward the roller 12 side. Next, when each claw 49 of the claw holding arm 46 is rotated to a vertically downward position as shown in FIG. let Along with this,
Since each claw holding arm 45, 46 moves toward the roller 12, the claw 49 of the claw holding arm 46 transfers the nuclear fuel pellet P on the tray 14 to the roller 12 side. At this time, at the transition between one end of the roller 12 and the end of the tray 14, the roller moving mechanism 16 adjusts the movement of the roller 12 vertically and horizontally to minimize the level difference. In addition, since a tapered surface 62 is formed at one end of the roller 12 near the end of the tray 14, when the nuclear fuel pellet P is transferred from the tray 14 to the roller 12, the nuclear fuel pellet P is There is no catch and it transfers smoothly.

Subsequently, as shown in FIG. 3, by lowering the piston rod 59 of the cylinder device 60 of the roller moving mechanism 16, one end of the roller 12 is lowered, and the bearing 18 attached to the one end of the roller 12 is moved. The tray 14 is fitted into the groove 17 on the upper surface of the roller support 10, and the tray 14 and the roller 12 are separated from each other. In this state, the motor 29 of the roller rotation drive mechanism 13 is operated to simultaneously rotate each roller 12 in the same direction and at the same speed. At this time,
The claw 49 of the claw holding arm 46 and the roller 12
Prior to rotation of the roller 12, the claw holding arms 45, 46 are slightly returned to the tray loading table 34 side so that the upper nuclear fuel pellets P do not contact and interfere with each other. Then, when the nuclear fuel pellet P rotates as the roller 12 rotates, the operator operates the mask mechanism to sequentially visually inspect the outer peripheral surface of the nuclear fuel pellet P in a limited, unmasked field of view. . At this time, the roller 12 is stopped or rotated by a manual switch at hand.
In addition, defective nuclear fuel pellets P are removed with tweezers.

On the other hand, a tray holding claw 37 is attached to the tray loading table 34.
By operating the tray rotation motor 38, the tray 14 fixed by the tray 14 is rotated clockwise as shown in FIG. do. Chips on tray 14 are therefore completely and easily removed. Next, the tray rotation motor 38
The tray 14 is rotated counterclockwise to return it to its original state.

Next, when all the nuclear fuel pellets P have been inspected, the motor 29 is stopped, the rotation of the roller 12 is stopped, and the piston rod 59 of the cylinder device 60 of the roller moving mechanism 16 is raised to move the As shown in FIG. 2, the corrugated plate 30 of the tray 14 is brought into contact with one end of the roller 12. In this case, one end of the roller 12 is moved left and right by the groove 61 of the roller push-up fitting 56 of the roller moving mechanism 16, and the horizontal direction between the one end of the roller 12 and the corrugated plate 30 of the tray 14 is moved. Since the displacement is absorbed, the level difference between one end of the roller 12 and the tray 14 is minimized, and the roller 12 and the tray 14 are brought into close contact.

Next, by moving the pellet feeding supports 41 and 42 to the tray loading table 34 side, each of the claw holding arms 45 and 46 moves to the tray loading table 34 side, and the claw 49 of the claw holding arm 45 is moved to the roller 1 side.
2 and transfers the nuclear fuel pellet P to the tray loading table 34 side. At this time, at the transition portion between one end of the roller 12 and the end of the tray 14, the roller moving mechanism 16
The rollers 12 are adjusted to move vertically and horizontally, and the tray 14 is set at a slightly lower position than the rollers 12. Therefore, when the nuclear fuel pellets P are transferred from the rollers 12 to the tray 14, the nuclear fuel pellets P overhangs the end of the tray 14 and smoothly transfers onto the tray 14. Also,
At this time, the rotation mechanism 55 is operated to rotate the claw 49 of the claw holding arm 46 to the position shown in FIG. 11.

Next, when all the inspected nuclear fuel pellets P are placed on the tray 14, the tray holding claws 37 fixing the tray 14 to the tray loading table 34 are removed and the tray 14 is taken out.

In this way, the visual inspection of the nuclear fuel pellet P is carried out smoothly. In this case, the cylinder device 60 of the roller moving mechanism 16 moves the roller 12
While moving one end up and down, the groove 61 on the top surface of the roller push-up fitting 56 of the roller moving mechanism 16
Since the one end of the roller 12 is moved from side to side by the lever, the deviation between the one end of the roller 12 and the corrugated plate 30 of the tray 14 is absorbed, and the level difference between the one end of the roller 12 and the tray 14 is reduced. The tray 1 at one end of the roller 12 is minimized and
Together with the tapered surface 62 formed at the portion closer to the roller 4, the nuclear fuel pellets P are smoothly transferred between the roller 12 and the tray 14, and are not caught. Also, in the unlikely event that the nuclear fuel pellet P is not caught, or the claw holding arm 4
If the claws 49 of 5 and 46 come into contact with a tray or the like and an overload is applied to the claws 49, the claw support shaft 4
7 and the pawl retaining ring 48, the insertion hole 50 of the pawl retaining ring 48
The inner slip pin 52 moves outward against the spring force of the spring 53 and comes out of the groove 51 of the claw support shaft 47. As a result, the pawl retaining ring 48 rotates clockwise around the pawl support shaft 47 in FIG. 10, so that the pawl 49 is bent.
Or the nuclear fuel pellets P will not be scattered. Furthermore, when replacing the bearing 24 that supports the roller 12, it is necessary to remove the nut 25a for fixing the roller gear 25 and the set bolt 23 fixing the two upper and lower half shaft support members 19, 20. Therefore, the bearing 24 can be easily replaced, and the replacement time can be shortened. Furthermore, the roller rotation drive mechanism 13 is connected to each gear 25,
26 and 27, the motor 29 is directly connected to the drive system, eliminating the generation of foreign matter and reducing nuclear fuel pellets P.
It is possible to prevent foreign matter from adhering to the surface. Further, since the tray 14 can be rotated together with the tray loading table 34 by the tray rotation motor 38, it is easy to remove chips on the tray 14, and the chips can be completely removed.

"Effects of the Invention" As explained above, according to the present invention, a tray for placing an object to be inspected is installed at one end of a plurality of rotatably provided rollers so as to be able to approach and separate from the tray,
In addition, since each roller is provided with a roller moving mechanism for bringing one end of each roller into contact with the tray or separating it from the tray, when transferring the object to be inspected between the tray and the roller, The roller moving mechanism allows the object to be inspected to be transferred between the tray and the rollers by bringing one end of the roller into contact with the tray and directly transferring the object from the tray to the roller or from the roller to the tray. This can be carried out extremely smoothly, and it is possible to reliably prevent the object to be inspected from getting caught in the transfer section. In addition, when inspecting the object to be inspected by rotating it, by separating one end of the roller from the tray using the roller movement mechanism, the roller can be rotated smoothly without any problems. It has this excellent effect.

[Brief explanation of the drawing]

Figures 1 to 13 show an embodiment of the present invention. Figure 1 is a side view of nuclear fuel pellets being transferred from a tray to a roller, and Figure 2 is a side view of nuclear fuel pellets being transferred from a roller to a tray. Fig. 3 is a side view showing the rollers rotating;
The figure is an explanatory diagram showing the support mechanism for one end of the roller, and FIG. 5 is an explanatory diagram showing the upper part of the roller push-up fitting.
Figure 6 is a perspective view showing the roller rotation drive mechanism; Figure 7 is a perspective view showing the roller rotation drive mechanism;
The figure is a side view explaining the rotation of the tray loading platform.
The figure is a perspective view showing the pellet transfer mechanism, FIG. 9 is a sectional view showing the claw holding arm, and FIG. 10 is a sectional view when an overload is applied to the claw of the claw holding arm.
Fig. 11 is a side view showing the positional relationship between the claw holding arm and the tray, Fig. 12 is a side view illustrating the rotating operation of the claw holding arm, and Fig. 13 is a side view explaining the pellet transfer operation by the claw holding arm. Side view,
14 to 16 show a conventional appearance inspection apparatus, in which FIG. 14 is a side view, FIG. 15 is a plan view, and FIG. 16 is a plan view showing a mask mechanism. P...Object to be inspected (nuclear fuel pellet), 12...
Roller, 14...Tray, 15...Pellet transfer mechanism, 16...Roller moving mechanism.

Claims (1)

[Scope of utility model registration request] At least a pair of rollers are rotatably provided, and a tray for placing an object to be inspected is arranged at one end of each roller, and the object to be inspected is received between the tray and each roller. In an apparatus for inspecting the appearance of an object to be inspected, which transfers a rotary object to be inspected placed on the tray onto each of the rollers by a transfer mechanism and inspects the appearance of the object to be inspected, The tray is provided at one end of each of the rollers so as to be able to move toward and away from the roller, and each roller is provided with a roller moving mechanism for bringing one end of each roller into contact with or away from the tray. An appearance inspection device for an object to be inspected, characterized by: