JPH04366786A - Monitor for transport of article - Google Patents

Abstract

PURPOSE:To provide a monitor which can surely detect the height of an article and in which radiation detectors are in no danger of being broken and the number of photoelectric switches can be reduced. CONSTITUTION:A monitor for the transport of articles is installed near the exit of a radiation controlled area and radiation from an article 3 carried out of the controlled area is measured by radiation detectors 5-7 and a photoelectric switch 10 for detecting the height of the article 3 is provided. The photoelectric switch 10 is disposed upstream of the radiation measuring position of the transport passage of the article 3 and perpendicular to the transport passage of the article 3 and used to detect the height of the article 3.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an article unloading monitor for measuring radiation of articles being unloaded from a radiation controlled area such as a nuclear facility.

0002

2. Description of the Related Art Article unloading monitors are installed near the exit of a radiation controlled area of a nuclear facility, etc., and automatically determine whether or not there is surface contamination of articles being transported out of the controlled area. An example of a conventional article discharge monitor of this type is one constructed as shown in FIG.

[0003] The procedure for measuring the movement path and radiation of the article being carried out in this example is as follows. That is, an irregularly shaped article 3 is placed on a tray 2 disposed on a conveyor 1 at an article entrance (position A) and conveyed to a measurement position (position C). A vertically driven conveyor 4 which is set at position C and has a vertically driven radiation detector 5 at its lower part.
In order to adjust the sensitivity to suit the size of the article 3, the tray 2, article 3, vertically driven radiation detector 5, and vertically driven conveyor 4 are moved from the bottom to the top position as shown by arrow 11.

[0004] Radiation measurement of the object 3 is performed by a fixed radiation detector 7 and a vertically movable radiation detector 5, which are disposed between radiation detectors 6 fixed in the front, rear, left, and right directions. In this case, the radiation measurement is performed after adjusting the height of the article 3 in order to match the detection sensitivity described above. The height adjustment is performed in part B, which consists of a plurality of light emitters 8a and light receivers 8b arranged at equal intervals in the horizontal direction.
The photoelectric switch 8 detects the article 3 on the tray 2 depending on whether the light beam 13 is received by the light receiver 8b without being blocked, and the photoelectric switch 8 automatically detects the article 3 on the tray 2, and automatically sends it to the vertical drive conveyor 4 and the vertical drive radiation detector. 5 is being moved. Note that when the radiation measurement of the object 3 is completed, the tray 2, the article 3, the vertically driven radiation detector 5, and the vertically driven conveyor 4 move toward the arrow 1.
2, it is moved from top to bottom.

[0005]

[Problems to be Solved by the Invention] In the conventional article unloading monitor described above, the photoelectric switch for detecting the current height of the article 3 is located at position B, and the height is determined while raising the article 3. In such a case, the radiation detector 7 is often damaged. Below, we will discuss this in Figure 4.
Explain with reference to. As shown in FIG. 4, each light emitter 8a and light receiver 8b of the photoelectric switch 8 are located below the radiation detector 7, and the vertical drive conveyor 4 is arranged so that the vertical drive conveyor 4 can move up and down smoothly. They are arranged horizontally on both sides of , with a distance of x from each other. Therefore, as the article 3, the distance x between the photoelectric switches 8
If the protrusions 3a are formed at narrower intervals and extend in the vertical direction, the protrusions 3a cannot be detected by the photoelectric switch 8, and therefore the height of the article 3 is not detected. The radiation detector 7 is detected by the protrusion 3a of the article 3.
leads to damage.

Therefore, as a countermeasure, the distance between the light emitters 8a and the distance between the light receivers 8b of each photoelectric switch 8 may be set to be smaller than x, but in this case, a large number of photoelectric switches 8 may be arranged. have to be done, and the cost is high. Incidentally, even in conventional monitors, the above-mentioned problem occurs even if the photoelectric switch is arranged to cover the length of the radiation detector (the distance from the left to the right in the figure).

[0007] According to the present invention, the height of an article can be reliably detected;
It is an object of the present invention to provide an article delivery monitor in which a radiation detector is not damaged and the number of photoelectric switches can be reduced.

[0008]

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention is installed near the exit of a radiation controlled area and measures the radiation of an article being carried out from the controlled area with a radiation detector. In an article unloading monitor having a photoelectric switch for detecting the height of This is an article delivery monitor characterized in that the height of the article is detected thereby.

[0009]

[Operation] According to the present invention, a photoelectric switch is disposed upstream of the radiation measurement position on the article carrying route and perpendicular to the article carrying route, thereby detecting the height of the article. Therefore, the height of the article can be detected reliably, the radiation detector will not be damaged, and the number of photoelectric switches can be reduced.

0010

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of an article discharging monitor according to the present invention. Here, the same parts as in the conventional example described above are denoted by the same reference numerals, the explanation thereof is omitted, and the points different from the conventional example will be mainly explained. do. That is, instead of providing the conventional photoelectric switch 8, a photoelectric switch 10 consisting of a light emitter 10a and a light receiver 10b described below is installed on the conveyor 1.
and the vertical drive conveyor 4, and are arranged substantially perpendicularly to the sides of both ends of the rollers of the conveyor 1.

FIG. 2 is a diagram showing the relationship between the photoelectric switch 10, the tray 2, and the article 3 described above. A plurality of projectors 10a are perpendicular to the moving direction of the tray 2, and project light beams onto the protrusion 3a of the article 3. 14 is disposed near one axial end of one roller of the conveyor 1, for example, with a predetermined interval y in the vertical direction. Similarly, the plurality of light receivers 10b are perpendicular to the moving direction of the tray 2, and are arranged so that the projection 3a of the article 3 can be irradiated with the light beam 14. They are disposed near the axial end of the opposite side) with a predetermined interval y in the vertical direction.

In the photoelectric switch 10 having such a configuration, the light beam 14 from each light emitter 10a is received by each corresponding light receiver 10b, so that the light rays 14 from each light emitter 10a are received by the respective light receivers 10b. 10b is blocked by the protrusion 3a of the article 3, the light receiver 10
The height of the protrusion 3a can be determined from the signal generated from the output side of the protrusion 3a. In other words, it can be determined based on which height position the photoelectric switch 10 is activated. The actual height may be determined by determining the position of the photoelectric switch 10 one step higher than the highest one of the activated photoelectric switches 10 as the height of the protrusion 3a of the article 3 driven by the vertical drive conveyor 4.

This height information is known before the article 3 arrives at the measurement position (position C) where radiation is measured by the radiation detectors 5 and 7, and the height information is immediately obtained at the measurement position (position C). Based on this, the vertical drive conveyor 4 can be moved to measure radiation.

As described above, the photoelectric switch 10 is
The height of the protrusion 3a of the article 3 can be reliably detected by arranging it before the radiation measurement position on the article 3 carry-in route and perpendicular to the article 3 carry-in route. Therefore, damage to the radiation detector 7 can be prevented. Further, the photoelectric switch 10 can reliably reduce the distance y corresponding to the tray 2 and the detection sensitivity, that is, the area corresponding to the detector sensitivity and the carrying tray portion, thereby reducing the cost.

[0015]

[Effects of the Invention] According to the present invention described above, it is possible to provide an article unloading monitor that can reliably detect the height of an article, prevent damage to the radiation detector, and reduce the number of photoelectric switches. be able to.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing an embodiment of an article discharge monitor according to the present invention.

FIG. 2 is a diagram for explaining a height detection method using the photoelectric switch in FIG. 1;

FIG. 3 is a schematic configuration diagram showing an example of a conventional article discharge monitor.

FIG. 4 is a diagram for explaining a height detection method using the photoelectric switch of FIG. 3;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1... Conveyor, 2... Tray, 3... Article, 4... Vertically driven conveyor, 5, 6, 7... Radiation detector, 10... Photoelectric switch.

Claims (1)

[Claims] [Claim 1] Installed near the exit of the radiation controlled area,
In an article unloading monitor that measures the radiation of an article being carried out from a controlled area using a radiation detector and has a photoelectric switch for detecting the height of the article, the photoelectric switch is placed at a position along the conveying route of the article. What is claimed is: 1. An article unloading monitor, which is disposed upstream from a radiation measurement position and perpendicular to an article carrying route, thereby detecting the height of the article.