JP2012159355A - X-ray foreign substance detection apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an X-ray shielding curtain capable of further reducing dangerousness of X-ray leakage by surely preventing the X-ray shielding curtain from being pierced into a test object and capable of reducing cost by a simple configuration.SOLUTION: An X-ray foreign substance detection apparatus 1 includes: a housing 3; a belt conveyer 8 for conveying a test object to a conveyance path in the housing 3; an X-ray generation part 11 for applying X-rays to the test object conveyed by the belt conveyer 8; an X-ray detection part 12 for detecting X-rays transmitted through the test object; a horizontal shaft 22 arranged on the conveyance path orthogonally to the conveyance direction Y of the belt conveyer 8; and an X-ray shielding curtain 20 in which curtain pieces 23 oscillatably suspended from the horizontal shaft 22 by attaching the base end sides of the curtain pieces 23 to the horizontal shaft 22 are formed like a plurality of strips. The X-ray shielding curtain 20 is arranged so that the curtain pieces 23 can be oscillated to the downstream side in the conveyance direction Y rather than a vertical direction, and oscillation to the upstream side of the conveyance direction Y is regulated.

Description

  The present invention irradiates an object to be inspected being transported on a transport path formed in the housing with X-rays, and is mixed in the object to be inspected based on the amount of X-rays transmitted through the object to be inspected. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray foreign object detection apparatus that detects a foreign object, and relates to an X-ray foreign object detection apparatus that includes an X-ray shielding curtain in a conveyance path so as not to leak X-rays out of a casing.

  X-ray foreign matter detection device irradiates X-rays on objects to be inspected (raw meat, fish, processed foods, pharmaceuticals, etc.) transported by a transport conveyor etc. to the transport path formed in the housing, and transmits the objects to be inspected This is a device for detecting foreign matter such as metal or bone mixed in the object to be inspected based on the amount of transmitted X-rays.

  In order to prevent X-rays from leaking out of the housing, the X-ray foreign object detection device is usually provided with an X-ray shielding curtain in the transport path within the housing. Conventionally, there is an X-ray shielding curtain disclosed in Patent Document 1 below. However, this X-ray shielding curtain is made of a resin sheet containing lead, which is an X-ray shielding material, and is preferably used in the case where the inspection object is packaged. However, the inspection object is raw meat or the like. In the case of unexposed food, it was not used because the lead component may adhere when the object to be inspected passes through the X-ray shielding curtain.

  For this reason, in the case where the object to be inspected is an exposed food, instead of the lead-containing X-ray shielding curtain, a metal plate made of SUS or the like is divided in a direction perpendicular to the transport direction and the strip-like metal plate is shaken. A movable X-ray shielding curtain is used. However, as shown in FIG. 6, the X-ray shielding curtain 101 swings greatly to the upstream side in the transport direction Y when the test object W passes, so that the X-ray shielding curtain 101 is moved to the test object W ′ transported subsequently. The X-ray shielding curtain 101 (metal plate 102) sometimes pierced. When the metal plate 102 is pierced into the inspection object W ′ in this way, there is a risk that the X-ray shielding curtain 101 is held in an open state and X-rays leak.

  Further, as shown in FIG. 7, there is an X-ray shielding curtain 201 in which a plurality of bent portions 203 are provided on a metal plate 202. The X-ray shielding curtain 201 can suppress the swinging of the X-ray shielding curtain 201 (metal plate 202) in the transport direction Y after the inspection object passes. Thereby, the metal plate 202 is not pierced by the subsequent inspection object, and leakage of X-rays due to the X-ray shielding curtain 201 being held open can be prevented. In addition, the X-ray shielding curtain in which the metal plate is configured to be bent in multiple stages as described above is disclosed in, for example, Patent Document 2 below.

  Further, there is one disclosed in Patent Document 3 below. As shown in FIG. 8, the X-ray shielding curtain 301 in this document is configured such that each curtain piece (metal plate) 302 is separated from the base end 303 a side, which is the side attached to the shaft 304, toward the front end 303 b side. 1 extends in a flat plate shape, and is bent into a shape corresponding to the height of the object to be inspected from the flat plate portion to the tip 303b to form a convex portion 305 on the upstream side in the transport direction Y. It is formed. In the X-ray shielding curtain 301, the curtain piece 302 swayed downstream in the transport direction Y tries to return to the original position after the inspection object passes, but passes through that position to the upstream side in the transport direction Y. Since the angle of contact with the object to be inspected that has been subsequently conveyed when swinging is small, the tip 303b of the curtain piece 302 swings following the movement of the object to be inspected without piercing the object. It becomes like this.

JP-A-11-160487 JP 2003-270174 A JP 2008-281416 A

However, the above-described X-ray shielding curtains 201 and 301 (see FIGS. 7 and 8) have the following drawbacks.
First, as shown in FIG. 7, the X-ray shielding curtain 201 is provided with a plurality of bent portions 203 on a metal plate 202. Here, the bent portion 203 has, for example, a metal plate piece 202a, 202b (or metal plate piece 202b, 202c) arranged vertically and nested in a hinge shape, and a connecting pin is inserted into this portion. It was structurally complex, such as being connected by. Therefore, since the X-ray shielding curtain 201 has a large number of bent portions 203, the structure is naturally complicated and the cost is high.

  Next, as shown in FIG. 8, the X-ray shielding curtain 301 suppresses the X-ray shielding curtain 301 from swinging up to the upstream side in the transport direction Y after the inspection object passes. As the object to be inspected is short, the tip 303b may pierce the object to be inspected because it swings to the upstream side in the transport direction Y. When the tip 303b pierces the object to be inspected, as described above, the X-ray shielding curtain 301 is held in an open state, and there is a risk that X-rays leak.

  Therefore, the present invention has been made in view of the above situation, and it is possible to reliably prevent the object from being pierced, further reducing the risk of X-ray leakage, and reducing the number of parts to a simple configuration. It aims at providing the X-ray foreign material detection apparatus provided with the X-ray shielding curtain which becomes low-cost by this.

Next, means for solving the above problems will be described with reference to the drawings corresponding to the embodiments.
The X-ray foreign object detection device according to claim 1 of the present invention includes a housing 3 having a shielding structure,
Transport means 8 for transporting the inspection object W to a transport path 7 formed in the housing 3;
X-ray irradiating means 11 for irradiating the inspection object W conveyed by the conveying means 8 with X-rays;
X-ray detection means 12 for detecting the X-ray transmitted through the inspection object W;
A horizontal shaft 22 provided in the transport path 7 perpendicular to the transport direction Y of the transport means 8;
An X-ray in which a curtain piece 23 suspended so as to be able to swing on the horizontal shaft 22 by being attached to the horizontal shaft 22 on the base end 24a side is provided in a plurality of strips in the axial direction of the horizontal shaft 22. In the X-ray foreign object detection device 1 including the shielding curtain 20,
The X-ray shielding curtain 20 has a configuration in which the curtain piece 23 is swingably provided on the downstream side in the transport direction Y with respect to the vertical, and swinging to the upstream side in the transport direction Y is restricted. is there.

  In such a configuration, when the object to be inspected W passes through the X-ray shielding curtain 20, the swing of the curtain piece 23 swayed downstream in the transport direction Y to the upstream side in the transport direction Y occurs. Due to the restriction, the object W will not swing to the upstream side in the transport direction Y from the original position when returning to the original position after the inspection object W has passed. Thereby, it is possible to prevent the curtain piece 23 from being stuck into the inspection object W ′ that has been subsequently conveyed.

  The X-ray foreign matter detection apparatus according to claim 2 is configured such that the X-ray shielding curtain 20 has a curved surface in which the tip 24b side of the curtain piece 23 is curved toward the downstream side in the transport direction Y.

  In such a configuration, the frictional resistance with the inspection object W when the inspection object W passes through the X-ray shielding curtain 20 is reduced, and the inspection object W passes smoothly.

In the X-ray foreign matter detection apparatus according to claim 3, the X-ray shielding curtain 20 is in contact with the base end 24 a side on the upstream side in the transport direction Y on the base end 24 a side of the curtain piece 23. A return preventing member 26 that regulates swinging toward the upstream side in the transport direction Y,
The return preventing member 26 is configured by a plate-like member extending in the axial direction of the horizontal shaft 22.

  In such a configuration, the number of components can be reduced and the swing of the X-ray shielding curtain 20 (curtain piece 23) to the upstream side in the transport direction Y can be restricted as a simple configuration.

  According to the X-ray foreign object detection device of the first to third aspects of the present invention, since the swing of the curtain piece to the upstream side in the conveyance direction is restricted, it is ensured that the curtain piece pierces the inspection object. Can be prevented. Thereby, X-ray leakage due to the X-ray shielding curtain being held open can be prevented. That is, the risk of X-ray leakage can be further reduced.

  Further, when the inspection object passes through the X-ray shielding curtain, the inspection object passes smoothly, and the inspection object can be prevented from being damaged.

  Further, the number of parts is reduced, and a simple configuration is realized, and the swing control to the upstream side in the transport direction of the X-ray shielding curtain (curtain piece) is realized, thereby reducing the cost.

It is a front view which shows one Embodiment of the X-ray foreign material detection apparatus by this invention. It is a side view which shows the same embodiment. It is a top view which shows the X-ray shielding curtain unit in the same embodiment. It is a front view which shows the X-ray shielding curtain in the same embodiment. (A), (b), (c) It is a front view which shows operation | movement of the X-ray shielding curtain in the embodiment. (A), (b) It is a front view which shows operation | movement of the conventional X-ray shielding curtain. It is a front view which shows the conventional X-ray shielding curtain. It is a front view which shows the conventional X-ray shielding curtain.

Embodiments of the present invention will be specifically described below with reference to the drawings.
This embodiment (X-ray foreign object detection device) irradiates an object to be inspected (raw meat, fish, processed food, pharmaceuticals, etc.) transported on a transport path formed in a housing, and inspects the object. This is a device for detecting foreign matter such as metal and bone mixed in the object to be inspected based on the amount of X-rays transmitted through the object.

  As shown in FIGS. 1 and 2, the X-ray foreign object detection device 1 includes a casing 3 having a substantially box-shaped shielding structure that is installed on a floor surface via legs 2 and 2. The housing 3 is made of a radiation protection material. On both side surfaces of the housing 3, a carry-in port 4 a through which the inspection object W is carried into the housing 3 and a carry-out port 4 b through which the inspection object W is carried out from the housing 3 are provided. Further, side covers 5 and 5 are provided on both side surfaces of the housing 3 so as to extend from the both side surfaces of the housing 3 to the left and right to cover these openings 4 (the carry-in port 4a and the carry-out port 4b). It has been. Furthermore, the front surface of the housing 3 is provided to be openable, and a door 6 that can be opened and closed is provided on the front surface of the housing 3.

  A conveyance path 7 for conveying the inspection object W is formed in the housing 3. A belt conveyor 8 as a conveying means for conveying the inspection object W to the conveying path 7 includes rollers 9a, 9b, 9c, 9d at both ends in the conveying direction Y, and these rollers 9a, 9b, 9c, 9d. An endless conveyance belt 10 is wound around the gap. Moreover, the conveyance belt 10 can be rotationally driven by connecting one of the rollers 9a and 9b to a drive motor (not shown). At this time, in the conveyance path 7, the belt surface of the conveyance belt 10 of the belt conveyor 8 becomes the conveyance surface (horizontal plane) of the inspection object W. In addition, the upstream side of the belt conveyor 8 in the transport direction Y is connected to a pre-stage conveyor for carrying the inspection object W from the preceding apparatus, and the downstream side of the conveyance direction Y is to unload the inspection object W to the downstream apparatus. A rear conveyor is connected.

Here, an optical system in the X-ray foreign matter detection apparatus 1 will be described.
As shown in FIGS. 1 and 2, an X-ray generation unit 11 that is an X-ray irradiation unit and an X-ray detection unit 12 that is an X-ray detection unit are disposed in the housing 3 so as to face each other. The X-ray generation unit 11 generates X-rays and irradiates the X-rays toward the X-ray detection unit 12. The X-ray detection unit 12 includes a line sensor in which a large number of light receiving elements are arranged in a line in the width direction of the belt conveyor 8 (conveying belt 10). The X-ray detection unit 12 is connected to an external computer, captures and processes the signal output from the X-ray detection unit 12 at a predetermined timing, and creates an image with a light / dark distribution corresponding to the X-ray transmission amount. Thus, the inspection object W is inspected for foreign matter contamination.

  In the X-ray foreign matter detection apparatus 1, the X-ray generation unit 11 is provided at a position directly above the belt conveyor 8 in the housing 3 at a predetermined distance. Further, the X-ray detection unit 12 is provided at a position directly below the belt conveyor 8. The position immediately below the X-ray generation unit 11 or the position directly above the X-ray detection unit 12 in the transport path 7 is an inspection position in the X-ray foreign matter detection apparatus 1.

From here, the X-ray shielding curtain which is the gist of the present invention will be described.
As shown in FIG. 1, the X-ray shielding curtain 20 is disposed in the transport path 7. The X-ray shielding curtain 20 is provided on the upstream side in the transport direction Y and the downstream side in the transport direction Y with the inspection position as the center. In this embodiment, three rows of X-ray shielding curtains 20 are provided on the upstream side and the downstream side in the transport direction Y. Further, as shown in FIG. 3, the X-ray shielding curtain 20 is unitized on the upstream side and the downstream side in the transport direction Y with the inspection position as the center (curtain units 21 and 21 to be described later).

  As shown in FIG. 4, the X-ray shielding curtain 20 includes a horizontal shaft 22, a curtain piece 23, and a return prevention member 26.

  The horizontal shaft 22 is provided in the upper part of the transport path 7 so as to be orthogonal to the transport direction Y. A curtain piece 23 made of a metal plate is suspended from the horizontal shaft 22 so as to be swingable. As shown in FIG. 2, the curtain piece 23 is provided in the form of a plurality of strips arranged in a direction orthogonal to the transport direction Y.

  The curtain piece 23 is formed in a substantially tubular shape with one end (base end) 24 a having a diameter slightly larger than the diameter of the horizontal shaft 22. The tubular portion (base end 24a) is open about one third of the circumference thereof, and can be easily and freely attached to and detached from the horizontal shaft 22. Further, the other end (tip) 24 b side of the curtain piece 23 is formed to be curved so that the tip 24 b faces the downstream side in the transport direction Y in a state where the X-ray shielding curtain 20 is attached to the transport path 7. . Accordingly, the curtain piece 23 has a flat surface that continues from the base end 24a side, and has a curved surface from the point at which it approaches the front end 24b side.

  Further, reinforcing ribs 25 that are bent toward the downstream side in the transport direction Y are provided at both end portions of the curtain piece 23. Therefore, as shown in FIG. 3, the curtain piece 23 is substantially U-shaped in a plan view.

  The curtain piece 23 has X-ray shielding properties, and is preferably made of SUS (stainless steel) from the viewpoint of durability and hygiene.

  As shown in FIG. 4, a return preventing member 26 is provided on the upstream side in the transport direction Y on the base end 24 a side of the curtain piece 23. The return preventing member 26 is formed by bending a plate-like member, and includes a contact plate portion 27 extending along the horizontal shaft 22 at a portion contacting the base end 24 a side of the curtain piece 23. The return preventing member 26 has a function of restricting the swing of the curtain piece 23 to the upstream side in the transport direction Y, and the tip 24b side is arranged downstream of the transport direction Y in the stationary state of the curtain piece 23. It has a function of tilting. Therefore, the curtain piece 23 is disposed slightly inclined to the downstream side in the transport direction Y from the vertical with respect to the transport surface that is a horizontal plane (the belt surface of the transport belt 10 of the belt conveyor 8). The inclination angle of the curtain piece 23 is preferably about 5 degrees.

Here, the swinging operation of the X-ray shielding curtain (curtain piece) will be described with reference to FIG.
As shown in FIG. 5 (a), the curtain piece 23 waits for the inspection object W in a still state slightly inclined so that the tip 24b side is arranged on the downstream side in the transport direction Y. FIG. ), When the inspection object W being conveyed by the belt conveyor 8 passes through the X-ray shielding curtain 20, the curtain piece 23 passes while pushing the curtain piece 23 downstream in the conveyance direction Y. The tip 24b side swings downstream in the transport direction Y with the base end 24a side as an axis. And as shown in FIG.5 (c), when the to-be-inspected object W passes, the curtain piece 23 swung to the downstream side of the conveyance direction Y will return to the original position (static state), and the upstream of the conveyance direction Y. Swings toward the side. At this time, the base end 24a side abuts against the abutting plate portion 27 of the return preventing member 26, and swinging to the upstream side in the transport direction Y from the original position is restricted. Wait for W '.

  As shown in FIG. 1, the X-ray shielding curtain 20 is arranged in three rows on the upstream side and the downstream side in the transport direction Y with the inspection position as the center, and on the upstream side and the downstream side in the transport direction Y. The curtain units 21 and 21 are provided as described above. The curtain unit 21 includes a mounting base 28, and the horizontal shaft 22 described above is provided on the mounting base 28. The attachment base 28 is detachably attached to the housing 3 so as to be disposed on the upper portion of the conveyance path 7. In the curtain unit 21, the X-ray shielding curtain 20 a located close to the inspection position has a curtain piece 23 a shorter than the other X-ray shielding curtains 20 so as not to interfere with the X-ray irradiation when the inspection object passes. It has become.

  As shown in FIG. 3, an interlock switch 29 for detecting the mounting state of the mounting base 28 is provided at the mounting position of the mounting base 28 in the housing 3.

  According to the above-described embodiment, when the object W being transported passes through the X-ray shielding curtain 20, the curtain piece 23 swung to the downstream side in the transport direction Y moves to the upstream side in the transport direction Y. Since the swinging is restricted, the swinging to the upstream side in the transport direction Y from the original position does not occur when the inspection object W tries to return to the original position after passing through. Thereby, it is possible to prevent the curtain piece 23 from being stuck into the inspection object W ′ that has been subsequently conveyed.

  Further, since the X-ray shielding curtain 20 has a curved surface formed by curving the front end side of the curtain piece 23, the frictional resistance with the inspection object W when the inspection object W passes is reduced, and the inspection object W is It will pass smoothly.

  Furthermore, since the configuration is simple, the swing of the X-ray shielding curtain 20 (curtain piece 23) to the upstream side in the transport direction Y can be regulated as a simple configuration by reducing the number of parts. As a result, the cost can be reduced and the cleaning property is improved.

  Further, since the interlock switch 29 is provided, it is possible to eliminate malfunction such as operation of the apparatus in a state where the curtain unit 21 (X-ray shielding curtain 20) is not attached. Thereby, safety is improved.

DESCRIPTION OF SYMBOLS 1 ... X-ray foreign material detection apparatus 3 ... Housing 7 ... Conveyance path 8 ... Belt conveyor as conveyance means 11 ... X-ray generation part as X-ray irradiation means 12 ... X-ray detection part 20 as X-ray detection means 20 ... X Line shielding curtain 22 ... Horizontal axis 23 ... Curtain piece 24a ... Base end 24b ... Front end 26 ... Return prevention member W ... Inspection object Y ... Conveying direction

Claims (3)

A shielding housing (3);
Transport means (8) for transporting the object to be inspected (W) to a transport path (7) formed in the housing;
X-ray irradiation means (11) for irradiating the inspection object conveyed by the conveyance means with X-rays;
X-ray detection means (12) for detecting the X-ray transmitted through the inspection object;
A horizontal axis (22) provided perpendicular to the transport direction (Y) of the transport means in the transport path;
The curtain piece (23) suspended swingably on the horizontal axis by attaching the base end (24a) side to the horizontal axis is provided in a plurality of strips in the axial direction of the horizontal axis. In an X-ray foreign object detection device (1) comprising a line shielding curtain (20),
The X-ray shielding curtain is provided such that the curtain piece is swingable to the downstream side in the transport direction from the vertical, and swinging to the upstream side in the transport direction is restricted. Wire foreign matter detection device.   The said X-ray shielding curtain (20) has the curved surface formed by curving the front-end | tip (24b) side of the said curtain piece (23) toward the downstream of the said conveyance direction (Y). X-ray foreign object detection device. The X-ray shielding curtain (20) is in contact with the base end side on the upstream side in the transport direction (Y) on the base end (24a) side of the curtain piece (23), thereby upstream of the transport direction. A return preventing member (26) for restricting the swing toward the side,
3. The X-ray foreign object detection device according to claim 1, wherein the return preventing member is a plate-like member extending in the axial direction of the horizontal axis (22).

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