JP3667747B2 - X-ray inspection system - Google Patents

Description

  The present invention relates to an X-ray foreign substance inspection apparatus capable of detecting not only metallic foreign substances contained in articles but also non-metallic foreign substances.

  A conventional X-ray foreign substance inspection apparatus is provided with a conveyor and an X-ray source in the apparatus main body, and performs X-rays from the X-ray source to irradiate articles conveyed by the conveyor to perform foreign substance inspection. When the conveyor is dirty, the whole or the belt is removed from the apparatus and the cleaning operation is performed.

  However, if you forget to reset the conveyor or belt after the cleaning operation and the part of the device is in the open state, if you turn on the X-ray source by mistake, May leak.

  Therefore, an object of the present invention is to provide an X-ray foreign substance inspection apparatus that can effectively suppress external leakage of X-rays from the apparatus.

In order to achieve the above object, an X-ray foreign matter inspection apparatus according to the present invention performs foreign matter inspection in an article by X-rays from an X-ray source while conveying the article on a conveyance conveyor, A strip-shaped X-ray shielding curtain that is detachably suspended in an opening located on the conveyance path, and when it is detected that the X-ray shielding curtain is detached from the opening, X from the X-ray source Irradiation stopping means for stopping the irradiation of the line .

According to this configuration, when the X-ray shielding curtain is removed from the opening, there is no external leakage of X-rays from the opening.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view schematically showing the overall structure of the X-ray foreign substance inspection apparatus according to the first embodiment of the present invention. This inspection apparatus is arranged in the upper part of the width direction center part of the conveyance conveyor 2 in the apparatus main body 1, and the one conveyance conveyor 2 arrange | positioned in the intermediate | middle of an up-down direction inside the apparatus main body 1, and is conveyed by this. An X-ray source 3 for inspecting a metal or non-metal foreign matter contained in the article M by irradiating the article M to be irradiated with X-rays is provided. The transport conveyor 2 transports the article M in the transport direction (front) F and is set to be longer than the length of the apparatus body 1 in the front-rear direction FR, and both ends thereof are formed on both front and rear surfaces of the apparatus body 1. A part of the apparatus 11 is detachably attached to the apparatus main body 1 in a state of protruding partly outward from the opening 11.

  An outlet 12 for taking out the entire transport conveyor 2 to the outside is formed on one side of the apparatus body 1 in the left-right direction. A hinge-type X-ray shielding door 13 is attached to the outlet 12 so as to be opened and closed. It has been. In the figure, 5 is a controller of the entire apparatus, 16 is a display of a touch panel for displaying an operation during foreign object inspection, and 17 is a display for displaying an X-ray transmission image. Reference numeral 18 denotes a lead-like flexible X-ray shielding curtain containing lead, which is suspended from the opening 11.

  FIG. 2 is a front view of the apparatus main body 1. When the conveyor 2 is not set, that is, when the conveyor 2 is removed from a predetermined mounting position of the apparatus main body 1 for maintenance or replacement, a part of the apparatus main body 1, for example, below the conveyor 2 The part is opened and the X-rays are not shielded from the outside. Therefore, an open detector 4 such as a distance measuring type infrared sensor or a laser sensor for detecting this non-shielding state is provided on the upper portion of the conveyor 2. The detector 4 has a detection distance (distance to a member below the conveyor 2) when the conveyor 2 is not present, rather than a detection distance (distance to the conveyor 2) when the conveyor is present. By increasing the length, the non-shielding state is detected, and the X-ray irradiation from the X-ray source 3 is forcibly automatically stopped based on the detection signal. In this embodiment, two open detectors 4 are provided at upper positions facing both ends of the conveyor 2 in the width direction outside the X-ray irradiation range A of the X-ray source 3, and these open detectors are provided. 4 and 4 detect the non-shielding state where the conveyer 2 does not exist. The X-ray irradiation range A is a triangular range having the X-ray source 3 as the apex and the top surface of the conveyor 2 as the bottom when viewed from the front-rear direction FR.

  Each of the open detectors 4 is configured such that at least a part of the article M is outside the X-ray irradiation range A because the detection distance of the article M transported on the transport conveyor 2 is shorter than that of the transport conveyor 2. It is also detected that there is a slip-through state where the X-ray inspection is not performed. A detection unit 20 that detects X-rays from the X-ray source 3 is provided at a position facing the X-ray source 3 below the conveyor 2.

  FIG. 3 shows a block diagram of a control part for controlling the X-ray source 3 by the open detector 4. In the figure, the controller 5 is provided with an X-ray irradiation stopping means 6, the open detector 4 is connected to the input side of the controller 5, and a warning is given to the output side when the open detector 4 detects a slipped article. A warning means 7 such as a buzzer is connected. As the warning means 7, the X-ray transmission image display 17 may be blinked to issue a warning. Further, a power switch SW 1 is interposed between the X-ray source 3 and its power source E, and the power switch SW 1 is opened and closed by the X-ray irradiation stop means 6 of the controller 5.

  When the open detector 4 detects the unshielded state of the apparatus main body 1, the power switch SW 1 is turned off via the X-ray irradiation stop means 6 of the controller 5, and energization from the power source E to the X-ray source 3 is performed. Is automatically shut off directly. That is, after the conveyor 2 is removed and the cleaning operation is performed with the X-ray source 3 turned off by another manual or automatic main switch SW0, the main switch SW0 is turned on without forgetting to reset it. Even at times, the X-ray source 3 is stopped by the output from the X-ray irradiation stopping means 6 based on the open detector 4, so that external leakage of X-rays from the opening 11 of the apparatus main body 1 is eliminated.

  Further, when the X-ray inspection is performed while the article M is being transported by the transport conveyor 2, at least a part of the article M passes through the outside of the X-ray irradiation range A of the transport conveyor 2 and the X-ray inspection is performed. When a slip-through article is generated, the slip-through article is detected by the open detector 4. When the open detector 4 detects a slip-through article, a warning is issued from the warning means 7 by the output from the controller 5, so that the slip-through article is prevented from being mixed with a non-defective product and shipped. In addition to the warning means 7, another warning means for notifying the detection of the slip-through article may be provided.

  In the embodiment shown in the figure, a door switch SW2 for detecting the opening / closing operation of the X-ray shielding door 13 is provided between the X-ray source 3 and its power source E closer to the power source E than the power switch SW1. When 13 is opened, the energization from the power source E to the X-ray source 3 is automatically cut off directly by the door switch SW2 without going through the controller 5.

  Further, the opening detector 4 may detect the operation when an operation button is operated in the case of making a reservation change at the time of setup change. According to this, the X-ray source 3 is automatically stopped when, for example, the inspection target product is changed when the reservation is changed. Specifically, the X-ray source 3 is stopped by pressing a reservation call button. Moreover, irradiation of the X-ray source 3 is restarted by pressing an operation button provided on the display 16 (FIG. 1). For this reason, useless irradiation from the X-ray source 3 is prevented, and external leakage of X-rays is eliminated. That is, when the reservation is changed, the article M is not transported, and the article M is not subjected to X-ray inspection. By stopping the X-ray source 3 at this time, unnecessary irradiation of X-rays and external leakage are prevented. Is done.

  4 is a side view of the transfer conveyor 2, and FIG. 5 is a plan view thereof. The conveyor 2 includes a conveyor frame 21, a driving roller 22 supported on both sides in the front-rear direction of the conveyor frame 22, a driven roller 23 supported via a driven shaft 23 a, and outer circumferences of these rollers 22 and 23. The belt 24 for conveyance which consists of an endless flat belt suspended by this is provided. The conveyor frame 21 includes a long frame main body 21a and a short frame small piece 21b provided on the rear end side thereof. The small frame piece 21b has a bent fulcrum shaft 25 extending in the left-right direction with respect to the frame main body 21a. It is supported at the center so that it can be bent up and down. A driving unit 30 including a power source 30a such as a motor is provided on the lower front side of the flat belt 24, and between a driving wheel 30b provided on the driving unit 30b and a driving wheel 22b provided on the driving shaft 22a. The endless belt 30c is wound around and the flat belt 24 is rotated through the drive shaft 23a. In this embodiment, a ceiling member 21c facing the inner surface of the flat belt 24 is provided on the upper side of the frame body 21a and the frame piece 21b.

  Further, in this embodiment, the shaft 23a of the driven roller 23 is supported so as to be movable back and forth with respect to the short frame piece 21b, and a screw rod 27 is rotatably attached to the frame piece 21b and screwed thereto. A spring 29 is provided between the plate member 28 and the shaft 23a to press the driven roller 23 outward (backward). In this way, when the screw rod 27 is screwed to move the plate member 28 back and forth relative to the frame piece 21b, the driven roller 23 moves back and forth via the spring 29, whereby the driven roller 23 and the drive are driven. The length between the rollers 22 is adjusted. As a result, even if the length of the flat belt 24 varies, an appropriate tension is always applied to the belt 23, and the article M can be conveyed satisfactorily.

  The bending fulcrum shaft 25 is positioned below a straight line L connecting the rotation axes of the rollers 22 and 23 when the frame main body 21a and the frame piece 21b shown in FIG. In this way, when the frame piece 21b is linear with respect to the frame main body 21a, the frame piece 21b always tries to bend upward about the bending fulcrum shaft 25 by the elastic restoring force of the flat belt 24. At this time, the frame small piece 21b abuts on the ceiling member 21c on the frame main body 21a side, and the upward bending of the frame small piece 21b is prevented. Further, since the bending fulcrum shaft 25 is located below the rotation axis, the bending to the lower side of the frame piece 21b does not occur. As a result, the frame main body 21a and the frame small piece 21b are stably supported in a linear posture by the elastic restoring force of the flat belt 24, and the articles M can be reliably conveyed to the front F.

  When performing foreign object inspection, as shown by the solid line in FIG. 4, the frame body 21a and the frame piece 21b are linear, and the flat belt 24 suspended on the driving and driven rollers 22, 23 is also linear. Set in the apparatus body 1 as described above. In this manner, the article M conveyed by the flat belt 24 is irradiated with X-rays from the X-ray source 3, and the foreign matter in the article M is inspected. Further, when the conveyor 2 is taken out and cleaning is performed, the frame piece 21b is bent downward with respect to the frame main body 21a about the bending fulcrum shaft 25 as shown by the phantom line in FIG. The entire length of the transfer conveyor 2 is made smaller than the front-rear width of the outlet 12 (FIG. 1) provided in the apparatus main body 1. Thereafter, if the entire conveyor 2 is taken out from the outlet 12 while adjusting the movement in the front-rear direction, the conveyor 2 is easily removed from the apparatus main body 1. Similarly, the conveyor 2 after cleaning can be easily set in the apparatus main body 1. That is, the conveyor 2 shortened by bending is put into the apparatus main body 1 from the outlet 12, and the small frame piece 21b is rotated upward to return to the original position linear with the frame main body 21a.

  4 and 5, X-rays and their scattering are present at the front and rear portions of the X-ray passage portion 2 a at the X-ray irradiation position from the X-ray source 3 at the intermediate portion in the longitudinal direction of the frame body 21 a of the conveyor 2. Two first shielding members 81, 81 that suppress the leakage of the wire in the front-rear direction of the apparatus main body 1 are attached to the frame main body 21 a in a state of extending across the entire width in the lateral direction of the transport conveyor 2. Further, two sheets for suppressing leakage of X-rays and scattered rays in the front-rear direction FR of the conveyor 26 at the front and rear portions of the X-ray irradiation position above the X-ray detection unit 20 provided below the conveyor 2. The second shielding members 82, 82 are attached in a state extending substantially over the entire width in the lateral direction of the transport conveyor 2.

  Further, a third shielding member 83 having a substantially L shape also serving as a bracket for supporting the rear end portion of the driving source 30 on the frame main body 21a is attached between the X-ray detection unit 20 and the driving source 30. The third shielding member 83 prevents X-rays and scattered rays from leaking in the front-rear direction FR. The first to third shielding members 81 to 83 are made of, for example, a stainless steel plate material that has an excellent shielding effect against X-rays. In this way, when the foreign matter in the article M is inspected, X-rays emitted from the X-ray source 3 and scattered rays generated by the X-rays hitting the surrounding portions are scattered in all directions and leaked. Is effectively suppressed by the shielding members 81 to 83.

  Further, as shown in FIG. 2, a drainage receiving member 9 that extends in the left-right direction perpendicular to the conveying direction of the apparatus main body 1 and that is inclined so that the left side is lower is provided at the lower part of the conveyor body 2 in the apparatus main body 1. A shielding plate 92 inclined to the lower right to shield the drainage port 91 from X-rays is attached above the drainage port 91 that opens and is formed in the lowest part of the bottom wall of the drainage receiving member 9. ing. When the inside of the apparatus main body 1 is cleaned, the cleaning water is collected in the drain receiving member 9 and discharged from the drain outlet 91 to the outside. Although the drain port 91 is open to the outside, since the shielding plate 92 is provided in the vicinity of the drain port 91, this prevents external leakage of X-rays and scattered rays from the drain port 91.

  FIG. 6 shows a perspective view of a mounting portion of the X-ray shielding curtain 18 of FIG. The shielding curtain 18 is composed of a plurality of flexible belt-like members containing lead, and these are attached to a frame 19 extending in the width direction constituting the apparatus main body 1 via a fixing tool 18a such as a mounting screw. An opening detector 40 for detecting that the shielding curtain 18 is detached and attaching the curtain 18 to the opening 11 is provided between the opening 11 and the opening 11 (FIG. 1). In the illustrated embodiment, a limit switch comprising male and female switches 41 and 42 is used as the open detector 40. The female switch 41 is disposed on the opening 11 side and the male switch 42 is disposed on the frame 19 side. The curtain 18 is detachably attached to the opening 11 via both switches 41 and 42. That is, the limit switch 40 also serves as a member that supports the shielding curtain 18 on the apparatus main body 1.

  The open detector 40 is connected to the power switch SW1 through the irradiation stop means 6 of the controller 5 in FIG. 3 as in the case described above. In this way, when the curtain 18 is removed from the opening 11, the X-ray source 3 is automatically stopped by the output from the X-ray irradiation stopping means 6 based on the open detector 40, so the opening 11 No external leakage of X-rays from

  FIG. 7 shows a second embodiment. In this embodiment, when the conveyor 2 is removed from the apparatus main body 1, the openings 11, 11 provided on the front and rear surfaces of the apparatus main body 1 and positioned on the conveyance path by the conveyor 2 are covered by the X-ray shielding shutter 51. I try to close it. That is, in FIG. 7A, an X-ray shielding shutter 51 for closing the opening 11 and a shutter driver 52 such as an air cylinder for opening and closing the shutter 51 are provided on both front and rear surfaces of the apparatus main body 1. It is installed. When the conveyor 2 is removed from the apparatus main body 1, at least the area below the shielding curtain 18 in the opening 11 is opened, and the X-ray is not shielded from the outside. Based on the opening detection signal from the opening detector 4 that detects this state, the drive control means 53 in the controller 5 closes the shutter driver 52 and lowers the X-ray shielding shutter 51 to the closing position to open the opening. 11 is closed. As shown in FIG. 7B, the X-ray shielding shutter 51 is guided by the left and right guide members 54 fixed to the apparatus main body 1 and moves in the vertical direction.

  According to this configuration, as shown in FIG. 7C, when the conveyor 2 is removed and the opening 11 is in the open state, the open detector 4 detects this open state, and based on this, X Since the line shielding shutter 51 closes the opening 11, even if the X-ray source 3 is erroneously turned on, the X-rays reflected or scattered from the X-ray source 3 inside the apparatus are not opened. 11 can be prevented from leaking outside. Moreover, since the X-ray shielding shutter 51 shields not the X-rays emitted from the X-ray source 3 but the weak X-rays reflected inside the apparatus, a thin and simple structure is sufficient.

  FIG. 8 shows a third embodiment. In this embodiment, when the conveyor 2 is removed from the apparatus main body 1, the opening 11 is closed by an X-ray shielding shutter 61 mechanically interlocked with the removal. That is, in FIG. 8A, an X-ray shielding shutter 61 for closing the opening 11 is provided on both front and rear surfaces of the apparatus main body 1, and a front guide member for guiding the front shutter 61 up and down. 62 is attached to the drive unit 30 below the conveyor 2, and a rear guide member 63 for guiding the rear shutter 61 up and down is attached to the X-ray detection unit 20. Each guide member 62, 63 is formed with a guide portion 64, 65 comprising a guide groove. The front guide groove 64 has a horizontal portion and a vertical portion that opens upward from the rear end. The rear guide groove 65 has a horizontal portion and a vertical portion that opens upward from the front end thereof.

  Engaging portions 71 and 72 at the other ends of the link members 67 and 68 whose one ends are rotatably connected to the front and rear X-ray shielding shutters 61 are movable in the front and rear direction FR to the horizontal portions of the guide grooves 64 and 65. Furthermore, the hooking portions 73 and 74 are provided in the front and rear portions of the conveyor frame 21 of the conveyor 2, and the front hooking portion 73 is behind the front engaging portion 71 in the guide groove. 64, and a rear latching portion 74 is latched in the guide groove 65 on the front side of the rear engagement portion 72. Accordingly, the X-ray shielding shutter 61 is pushed upward by the engaging portions 71 and 72 being pressed forward and backward by the latching portions 73 and 74, respectively, and is held in the open position where the opening 11 is opened. Is done.

  From this state, when the conveyor portions 2 are bent upward from the vertical portions of the guide grooves 64 and 65 while bending the conveyor 2 as shown by a two-dot chain line in FIG. While the X-ray shielding shutter 61 and the link members 67 and 68 move rearward and forward, respectively, the X-ray shielding shutter 61 descends to the closing position, and the opening 11 is closed.

  According to this configuration, when the conveyor 2 is detached from the apparatus main body 1 and the opening 11 is about to be opened, the X-ray shielding shutter 61 closes the opening 11 mechanically in conjunction with the removal. Even if the X-ray source 3 is erroneously turned on, it is possible to prevent leakage of X-ray reflected rays and scattered rays from the opening 11 to the outside. Moreover, since the X-ray shielding shutter 61 shields not the X-rays emitted from the X-ray source 3 but the weak X-rays reflected inside the apparatus, a thin and simple structure is sufficient.

  In the third embodiment, the X-ray shielding shutter 61 is closed in conjunction with the removal of the conveyor 2, but unlike this, the shielding curtain 18 that covers the upper part of the conveyor 2 at the opening 11 is removed. The X-ray shielding shutter can be closed by mechanically interlocking. In that case, an X-ray shielding shutter 61 similar to that shown in FIG. 8 is provided in the vicinity of the opening 11. Further, a guide groove similar to the guide grooves 64 and 65 in FIG. 8 is provided above the opening 11, and the open detector 40 similar to that shown in FIG. Male and female switches 41 and 42 provided in the curtain frame 19 that supports the shielding curtain 18 are arranged in the inner part of the guide groove in a posture toward the inside of the apparatus along the direction FR. Removably attached in the front-rear direction FR. Further, one end of link members 67 and 68 similar to those shown in FIG. 8 is connected to the shielding curtain 18, and the engaging portions 71 and 72 at the other ends are engaged with the guide groove, The male and female switches 41 and 42 are attached to the open detector 40 by engaging the latching portions 73 and 74 provided on the curtain frame 19 with the guide grooves so as to sandwich 71 and 72. According to this configuration, when the shielding curtain 18 is removed from the opening 11, the X-ray shielding shutter 61 is lowered by its own weight and closes the opening 11, so that the X-ray source 3 is erroneously left with the shielding curtain 18 removed. Even if it is turned on, X-rays can be prevented from leaking from the opening 11 to the outside.

  In the first and second embodiments, the open detector 4 is disposed above the transport conveyor 2, but as shown in FIG. 9, a reflective photoelectric tube sensor 45 whose optical axis is set in the front-rear direction FR is used. A plurality of X-ray irradiation ranges A may be arranged along the side of the triangle. Among these, the lowest sensor 45 is an open detector 4 that is arranged in front of or behind the conveyor 2 and detects the presence or absence of the conveyor 2. The other sensor 45 reliably detects the slip-through article M at least partially passing outside the X-ray irradiation range A.

  Further, as shown in FIG. 10, as the open detector 4, reflective photoelectric tube sensors are arranged on both sides of the apex of the triangle of the X-ray irradiation range A, and the detection light beam from the photoelectric tube sensor 4 is directed toward the photoelectric tube sensor 4. Reflecting reflectors 47 may be arranged on both sides of the bottom of the triangle so that the detection light beam is along the side of the triangle. This also makes it possible to reliably detect the presence / absence of the conveyor 2 and the slipped article M.

  The display 16 in FIG. 1 is a touch panel. However, the display 16 may be displayed only and an operation key may be provided separately. Further, the X-ray transmission image displayed on the display 17 may be displayed on the display 16 and the display 17 may be eliminated.

  In the above embodiment, the case where one transport conveyor 2 is provided in the apparatus main body 1 has been described, but the present invention can also be applied to the case where two transport conveyors are provided in series inside the apparatus main body 1.

It is a perspective view of the X-ray foreign material inspection apparatus which shows 1st Embodiment of this invention. It is a front view of the inspection apparatus. It is a block diagram which shows the control part for controlling an X-ray source with a detector. It is a side view of the conveyance conveyor used for the inspection apparatus. It is a top view of the conveyance conveyor. It is a perspective view of the X-ray shielding curtain provided in the opening part of an apparatus main body. (A) is a side view of the X-ray foreign material inspection apparatus showing the second embodiment, (B) is a front view thereof, and (C) is a side view of the main part showing the operation. (A) is a side view of the X-ray foreign material inspection apparatus which shows 3rd Embodiment, (B) is a side view which shows operation | movement. It is a front view which shows the modification of an open | release detector. It is a front view which shows the other modification of an open | release detector.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Apparatus main body, 2 ... Conveyor, 3 ... X-ray source, 4,40 ... Opening detector, 6 ... Irradiation stop means, 7 ... Warning means, 11 ... Opening part, 12 ... Outlet, 81-83 ... Shielding Member, 9 ... drainage receiving member, 51, 61 ... X-ray shielding shutter, 64, 65 ... guide part, 67, 68 ... link member, 81, 82, 83 ... shielding member, 91 ... drain port, 92 ... shielding plate, A ... X-ray irradiation range, FR ... front-rear direction, E ... power source, M ... article, SW1 ... power switch

Claims (1)

An X-ray foreign matter inspection apparatus for inspecting foreign matter in an article by X-rays from an X-ray source while conveying the article on a conveyor,
A belt-shaped X-ray shielding curtain detachably attached to an opening located on the transport path by the transport conveyor ;
An X-ray foreign matter inspection apparatus comprising: an irradiation stop unit that stops X-ray irradiation from the X-ray source when it is detected that the X-ray shielding curtain is removed from the opening .

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