JP2004333264A - X-ray inspection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact and low-cost X-ray inspection device capable of achieving high detection precision. <P>SOLUTION: This X-ray detection device 1 is provided with a carrying means to carry an object M, an X-ray source 10 to radiate X-ray to the object M being carried by the carrying means, and an X-ray detector 11 to detect the X-ray L transmitted through the object M. The X-ray is radiated roughly vertically downward from the X-ray source 10 toward the X-ray detector 11, and the object M is inspected based on detection signals from the X-ray detector 11. The carrying means has an inclined part 30 to carry the object as it is inclined. The object M being carried in an inclined state at the inclined part is detected by the X-ray detector 11 as the X-ray L from the X-ray source 10 is transmitted. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an X-ray inspection apparatus that inspects an article being transported.
[0002]
[Prior art]
In a conventional X-ray inspection apparatus, for example, a thin foreign substance such as an egg shell attached to the surface of a fried egg has a small difference from the background of the article and is difficult to detect.
Therefore, there has been proposed an X-ray inspection apparatus in which the optical axis of the X-ray emitted from the X-ray source is inclined with respect to the transport direction of the article (for example, see Patent Documents 1 and 2). According to such a conventional apparatus, since the X-rays are obliquely incident on the article, the transmission distance to the foreign matter becomes longer, and therefore, the detection sensitivity is improved.
[0003]
[Patent Document 1]
JP-A-2002-62269 (pages 2-4, FIG. 1)
[Patent Document 2]
JP-A-2002-168802 (Page 2-6, FIG. 1)
[0004]
[Problems to be solved by the invention]
However, in the conventional X-ray inspection apparatus, since the X-ray optical systems such as the X-ray source and the X-ray detector are provided at an angle, the size of the apparatus is increased and the manufacturing cost is increased. In addition, since the X-ray irradiation direction is oblique, leakage of X-rays from the loading / unloading port of the article increases.
[0005]
Therefore, an object of the present invention is to provide an X-ray inspection apparatus capable of solving such various problems.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, an X-ray inspection apparatus of the present invention includes a conveying unit that conveys an article, an X-ray source that irradiates an X-ray to the article conveyed by the conveying unit, and the X-ray source that transmits the article. An X-ray detector for detecting X-rays, emitting X-rays from the X-ray source substantially vertically downward toward the X-ray detector, and inspecting an article based on a detection signal from the X-ray detector. An X-ray inspection apparatus for performing an X-ray inspection, wherein the conveying means has an inclined portion for conveying the article in an inclined state, and the X-ray from the X-ray source is used to convey the article conveyed in an inclined state in the inclined section. It is characterized in that the light is transmitted and detected by the X-ray detector.
[0007]
According to the present invention, since the X-rays from the X-ray source penetrate the article conveyed in the inclined state (posture) in the inclined section, the X-rays are incident on the article obliquely, so that the transmission distance for the foreign matter is transmitted. And the detection sensitivity is improved.
Further, since the optical system including the X-ray source and the X-ray detector is not arranged obliquely, the apparatus is not increased in size and the manufacturing cost is reduced.
Further, since the X-rays are irradiated in the vertical direction, the leakage of the X-rays from the carry-in / out port of the article does not increase.
[0008]
In the present invention, the term “inspection” includes a foreign substance inspection for detecting a foreign substance such as an egg shell, a needle, and a metal piece, in addition to the inspection for determining whether or not the product is acceptable.
[0009]
In the X-ray inspection apparatus, the length from the position where the X-rays are transmitted in the inclined portion to the end of the article reaching the transport surface below the inclined portion is set to be longer than the length of the article. Is preferred. With this setting, the irradiation of the X-rays to the article is completed before the article on the inclined section comes into contact with the discharge section. Therefore, the shape and posture of the article do not change during the transmission of the X-ray. Inspection can be performed.
[0010]
In addition, if the inclination angle of the inclined portion is adjustable, it is possible to set an appropriate sliding speed according to the type of the article, and it is possible to further improve the reproducibility of foreign object detection.
[0011]
The conveyance means includes the inclined section, a carry-in section that carries an article into an examination room and transfers the article to the inclined section, and a discharge section that receives the article from the inclined section and discharges the article outside the examination room. The part and the discharge part are set to be substantially horizontal or have an inclination different from that of the inclined part, so that the height of the downstream end of the loading part and / or the upstream end of the discharge part can be adjusted. Is preferred. As described above, if the height can be adjusted, the inclination angle of the inclined portion can be easily adjusted.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
In the following description, a fried egg will be described as an example of an article. In addition, the said fried egg is conveyed in the state of only a disk-shaped fried egg without a formwork or the like.
[0013]
overall structure:
As shown in FIG. 1, the X-ray inspection apparatus 1 provided on the transport line of the article M includes a housing 1S formed of an X-ray shield box. An inspection room 12 is formed inside the housing 1S so as to cover an optical system including an X-ray source 10 and an X-ray detector 11 with a housing (cover) 1S. The X-ray source 10 emits X-rays L along an optical axis C that is substantially parallel to the vertical direction Z. The X-rays L enter the X-ray detector 11.
[0014]
On both sides of the housing 1S, openings formed by a carry-in entrance 1a and a carry-out exit 1b are formed. In the housing 1S, a first conveyor (an example of a carry-in part) 50, an inclined part 30 are arranged in order from the upstream. And a conveying means including a second conveyor (an example of an unloading section) 20. The first conveyor 50 and the second conveyor 20 are set substantially horizontally.
[0015]
First conveyor 50:
The first conveyor 50 constitutes a carry-in section for carrying the articles M into the inspection room 12 and passing the articles M to the inclined section 30. An endless belt 5B is stretched on the first conveyor 50, and a driving roller 51 for driving the belt 5B is provided at an upstream end of the first conveyor 50. The drive roller 51 is rotated by a motor 53 provided below the first conveyor 50, and the article M on the belt 5B is conveyed.
The first conveyor 50 is provided at a higher level than the second conveyor 20. The downstream end 50d of the first conveyor 50 extends to a position upstream of the optical axis C, and an inclined portion 30 is provided from the downstream end 50d to a lower surface of the second conveyor 20 on the conveying surface.
[0016]
The inclined section 30 conveys the article M onto the second conveyor 20 by sliding down the article M in an inclined state (posture), as described later.
[0017]
Second conveyor 20:
The second conveyor 20 constitutes a discharge unit that receives the articles M from the inclined section 30 and discharges the articles M to the outside of the inspection room 12 from the carry-out port 1b. An endless belt 2B is stretched on the conveyor 20, and a drive roller 23 for driving the conveyor belt 2B, a tension roller 22, and the like are provided below the second conveyor 20.
In addition, both ends 21a of the second conveyor 20 can be lifted upward, respectively. At the time of cleaning or maintenance, the both ends 21a are rotated upward to remove the transport belt 2B. Is possible.
[0018]
Articles M carried into the carry-in entrance 1 a from the upstream conveyor 60 are conveyed onto the first conveyor 50. The article M is conveyed on the first conveyor 50 and carried into the inspection room 12, then slides down on the inclined portion 30 from the downstream end 50 d of the first conveyor 50, and is conveyed on the second conveyor 20. The article M is conveyed on the second conveyor 20, is carried out of the housing 1S from the outlet 1b, and is conveyed on the downstream conveyor 61.
The downstream conveyor 61 is provided with a sorting device (not shown), and if it is determined that the article is defective in the inspection, the article is sorted out of the system.
[0019]
Optical systems 10, 11:
The X-ray source 10 generates X-rays and irradiates the X-rays to an X-ray detector 11. The X-ray detector 11 includes a line sensor in which a number of pixels are arranged in one row in the width direction of the second conveyor 20. A computer (not shown) is connected to the X-ray detector 11. The computer inspects the article M by capturing and processing a detection signal from the X-ray detector 11 at a predetermined timing and creating an image having a distribution of light and dark according to the amount of transmitted X-rays.
[0020]
Inclined part 30:
As shown in FIG. 2, the inclined portion 30 includes a first inclined plate 31 whose upstream end is located near the downstream end 50 d, and a second inclined plate 32 provided diagonally below the first inclined plate 31. It has. The two inclined plates 31 and 32 are made of, for example, a metal plate having a concave cross section, and have inclined surfaces 31a and 32a on which the articles M slide down, respectively, are formed on the bottom surfaces thereof. The inclined surfaces 31a and 32a are set at substantially the same inclination angle at a predetermined distance. At the time of inspecting foreign matter, the X-rays L are emitted toward the space between the inclined surfaces 31a and 32a, and the X-rays L pass through the article M conveyed in an inclined state. 11 is detected.
[0021]
The length from the position where the X-rays L penetrates on the inclined portion 30 to the conveying surface of the second conveyor 20, that is, the distance D1 from the point O1 to the point O2 (hereinafter, referred to as “reach distance”) D1 is The length is set to be longer than the length D2 in the transport direction Y.
Here, when the article M moves from the second inclined surface 32a onto the second conveyor 20, the angle at which the article M is conveyed changes, so that the shape and posture of the article M change. Therefore, the reaching distance D1 is set to be longer than the length D2 of the article M. Thereby, it is possible to prevent the shape and the posture of the article M from being changed during the transmission of the X-ray, and to perform a highly accurate inspection.
[0022]
Adjustment of the inclination angle of the inclined portion 30:
As shown in FIG. 3, the first inclined plate 31 is attached to the main body 50s of the first conveyor 50 via the first bracket 31b. The inclination angle of the first inclined plate 31 can be changed as indicated by a two-dot chain line around the rotation shaft 31c attached to the first bracket 31b. The mounting position of the first inclined plate 31 can be changed in the transport direction Y with respect to the first bracket 31b.
On the other hand, the second inclined plate 32 is attached to the main body 20s of the second conveyor 20 via the second bracket 32b. The inclination angle of the second inclined plate 32 can be changed as indicated by a two-dot chain line around the rotation shaft 32c attached to the second bracket 32b.
Therefore, it is possible to change the inclination angles of the inclined plates 31, 32 by rotating the inclined plates 31, 32, respectively.
On the other hand, the first inclined plate 31 is moved in the transport direction Y so that the article M does not collide with the tip of the second inclined plate 32, and the transport levels of the two inclined surfaces 31a and 32a are substantially flush with each other. It is possible to fit on top.
[0023]
Adjusting the height of the first conveyor 50:
As shown in FIG. 4, the first conveyor 50 rotates the first conveyor 50 about the rotation axis O of the drive roller 51 to increase the height of the downstream end 50 d as shown by a two-dot chain line. It is possible to move in the vertical direction Z. The height of the downstream end 50d is adjusted by raising and lowering an adjusting member 52 that supports the lower portion of the first conveyor 50.
Therefore, the height of the downstream end 50d of the first conveyor 50 can be adjusted.
[0024]
An X-ray shielding member (not shown) for preventing X-rays from leaking out of the inspection apparatus 1 is provided on the transport path of the article M by the first and second conveyors 50 and 20. Have been. The X-ray shielding member is formed, for example, by hanging a goodwill-shaped shielding member from above.
[0025]
Operation during inspection:
When the inspection is started, X-rays are emitted from the X-ray source 10 to the X-ray detector 11 in FIG. 1, and after the article M is conveyed from the upstream conveyor 60 onto the first conveyor 50, It is sent into the inspection room 12 by the first conveyor 50. Articles M on the first conveyor 50 are transferred from the first conveyor 50 onto the inclined portion 30 and transferred to the second conveyor 20 after the X-ray inspection is performed. The article M on the second conveyor 20 is conveyed to the outside of the inspection room 12 from the outlet 1b, and is then conveyed downstream by the downstream conveyor 61.
[0026]
Here, while the article M on the inclined portion 30 moves from the first inclined plate 31 to the second inclined plate 32, the X-rays L penetrate the article M while sliding down in an inclined posture, and the transmitted X-rays L is detected by the X-ray detector 11. The computer inspects an article based on a detection signal from the X-ray detector 11.
[0027]
As described above, since the X-rays L from the vertical direction Z are transmitted to the article M conveyed in the inclined state in the inclined section 30, the X-rays L are obliquely incident on the article M. The transmission distance becomes longer and the detection sensitivity can be improved. Therefore, even a thin foreign substance such as an egg shell can be detected.
Further, since it is not necessary to dispose the optical system including the X-ray source 10 and the X-ray detector 11 obliquely, the size of the apparatus is not increased, and the manufacturing cost is reduced.
Further, since the X-rays are not irradiated from an oblique direction, the leakage of the X-rays from the loading / unloading port of the article does not increase.
[0028]
Angle adjustment:
When adjusting the inclination angle of the inclined part 30, the inclination plates 31 and 32 are rotated such that the inclination angles of both the inclination plates 31 and 32 are substantially the same. On the other hand, the first inclined plate 31 is moved in the transport direction Y to adjust the two inclined surfaces 31a and 32a so that the transport surfaces are arranged on the same plane.
As described above, by adjusting the inclination angle of the inclined portion 30, it is possible to appropriately adjust the sliding speed according to the type of the article, and it is possible to further improve the reproducibility of foreign object detection.
The speed at which the article M slides down on the inclined portion 30 is adjusted so that transfer of the article M from the first conveyor 50 and transfer to the second conveyor 20 can be performed smoothly. Preferably, the speed is set to be substantially the same as the speed.
[0029]
On the other hand, if necessary, the first conveyor 50 is rotated about the rotation axis O of the driving roller 51 by moving the adjusting member 52 up and down, and the height of the downstream end 50d is changed. By adjusting the height, the angle of the inclined portion 30 can be easily adjusted, and the distance between the first inclined plate 31 and the second inclined plate 32 can be adjusted to be constant.
[0030]
In the above-described embodiment, the height of the downstream end 50d of the first conveyor 50 is adjustable, but the height of the upstream end of the second conveyor 20 may be adjusted instead of the first conveyor 50. Good. Further, both the height of the downstream end 50d of the first conveyor 50 and the height of the upstream end of the second conveyor 20 may be adjusted.
[0031]
Further, in the above-described embodiment, the inclined portions 30 are plate-shaped inclined plates 31 and 32. However, instead of the inclined plates 31 and 32, as shown in FIGS. A conveyor 30A or a belt conveyor 30B may be employed.
Further, as shown in FIG. 5C, a parallel movement mechanism may be formed by the first conveyor 50, the inclined portion 30, and the second conveyor 20. The first conveyor 50 is translated in accordance with the angle of the inclined portion 30. In such a case, the inclined portion 30 may be formed of a single plate material, and the transmission hole E through which the X-rays L pass may be formed in the inclined portion 30.
[0032]
The article may be an article other than the fried egg. The foreign matter may be other than the egg shell.
[0033]
【The invention's effect】
As described above, according to the present invention, since the X-rays from the X-ray source penetrate the article conveyed in the inclined state at the inclined section, the X-rays are obliquely incident on the article. , The transmission distance with respect to is increased, and the detection sensitivity is improved.
Further, since the optical system including the X-ray source and the X-ray detector is not arranged obliquely, the apparatus is not increased in size and the manufacturing cost is reduced.
Further, since the X-rays are irradiated in the vertical direction, the leakage of the X-rays from the carry-in / out port of the article does not increase.
[Brief description of the drawings]
FIG. 1 is a partially broken schematic side view showing an X-ray inspection apparatus according to an embodiment of the present invention.
FIG. 2 is a schematic side view showing an inspection room.
FIG. 3 is a schematic side view showing a method of adjusting a tilt angle of a tilt portion.
FIG. 4 is a schematic side view showing a method for adjusting the height of a loading section.
FIG. 5 is a schematic side view showing a modification.
[Explanation of symbols]
10: X-ray source 11: X-ray detector 12: inspection room 20: second conveyor (ejecting unit, transport means)
30: Inclined part (transportation means)
50: 1st conveyor (loading unit, transport means)
M: Goods

Claims (4)

Conveying means for conveying the article;
An X-ray source for irradiating the article conveyed by the conveying means with X-rays;
An X-ray detector that detects the X-ray transmitted through the article,
An X-ray inspection apparatus that emits X-rays substantially vertically downward from the X-ray source toward the X-ray detector, and inspects an article based on a detection signal from the X-ray detector,
The transporting means has an inclined portion for transporting the article in an inclined state, and the X-ray from the X-ray source penetrates the article transported in the inclined state at the inclined section and is detected by the X-ray detector. X-ray inspection apparatus. In claim 1,
An X-ray inspection apparatus, wherein a length from a position where the X-rays are transmitted in the inclined portion to a point where the tip of the article reaches a transport surface below the inclined portion is set longer than a length of the article. In claim 1 or 2,
An X-ray inspection apparatus wherein the inclination angle of the inclined portion is adjustable. In claim 3,
The conveyance means includes the inclined section, a carry-in section that carries an article into an examination room and transfers the article to the inclined section, and a discharge section that receives the article from the inclined section and discharges the article outside the examination room. The part and the discharge part are set to be substantially horizontal or have an inclination different from that of the inclined part, so that the height of the downstream end of the loading part and / or the upstream end of the discharge part can be adjusted. Line inspection equipment.

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