X-ray inspection equipment

Abstract

Provided is an X-ray inspection device that can prevent leakage of X-rays while reducing the risk of foreign matter being mixed into an item to be inspected. [Solution] The X-ray inspection device 1 comprises a conveying section 5 that conveys an item G, an X-ray irradiation section 6 that irradiates X-rays onto the item G conveyed to the inspection area 4 by the conveying section 5, an X-ray detection section 7 that detects X-rays that have passed through the item G, an inspection section 10 that inspects the item G based on the detection results of the X-ray detection section 7, an X-ray shielding member 60 that is a flexible X-ray shielding member that prevents X-rays from leaking from the conveying path 4c to the inspection area and is suspended from the conveying path 4c, and a front member 50 that is arranged upstream of the X-ray shielding member 60 so as to overlap with the X-ray shielding member 60 and has higher impact resistance or abrasion resistance than the X-ray shielding member 60.

Description

[Technical Field]

[0001] One aspect of the present invention relates to an X-ray inspection apparatus. [Background technology]

[0002] Conventionally, X-ray inspection devices have been known that include an X-ray leakage prevention member (such as a shielding curtain) for preventing X-ray leakage. Such X-ray leakage prevention members are made of a flexible material containing tungsten or other materials. However, because such X-ray leakage prevention members have high surface friction resistance, if the object to be inspected is lightweight or has a shape that is easily caught, when the object comes into contact with the X-ray leakage prevention member during transport, it may get caught and stop, or the object's position may change, making it impossible to perform the inspection normally. To address this problem, for example, Patent Document 1 discloses a flexible sliding sheet made of a material with a low surface friction coefficient, which is provided on the front side of the X-ray leakage prevention member in the transport direction of the object, thereby preventing X-ray leakage and stabilizing the transport of the object. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-228601 Summary of the Invention [Problem to be solved by the invention]

[0004] However, even if the conventional X-ray inspection device described above can stabilize the transport of articles, the sliding sheet can be worn and damaged by contact with the articles, creating a risk of foreign matter being mixed into the articles.

[0005] Therefore, an object of one aspect of the present invention is to provide an X-ray inspection apparatus that can prevent leakage of X-rays while reducing the risk of foreign matter being mixed into an item to be inspected. [Means for solving the problem]

[0006] (1) An X-ray inspection device according to one aspect of the present invention includes a conveying unit that conveys an object, an X-ray irradiation unit that irradiates X-rays onto the object conveyed to an inspection area by the conveying unit, an X-ray detection unit that detects X-rays that have passed through the object, an inspection unit that inspects the object based on the detection results of the X-ray detection unit, a flexible X-ray shielding member that prevents X-rays from leaking from a conveying path that conveys objects into or out of the inspection area, the X-ray shielding member being suspended from the conveying path, and a front member that is arranged upstream of the X-ray shielding member so as to overlap with the X-ray shielding member and has higher impact resistance or abrasion resistance than the X-ray shielding member.

[0007] In an X-ray inspection device with this configuration, a front member that is impact-resistant or abrasion-resistant is provided upstream of the X-ray shielding member, reducing the frequency with which articles conveyed from the upstream side come into direct contact with the X-ray shielding member. This reduces the possibility of damage to the X-ray shielding member. As a result, it is possible to prevent X-ray leakage while reducing the risk of foreign matter being mixed into the articles to be inspected.

[0008] (2) In the X-ray inspection apparatus of (1), at least the outer surface of the front member may be made of a metal material. In this configuration, the front member can be easily formed to have higher impact resistance and abrasion resistance than the X-ray shielding member.

[0009] (3) In the X-ray inspection device of (1) above, the front member may be a thin plate-shaped leaf spring member made of a metal material. In this configuration, even if the front member is made thin and deformed by being hit by an object, it can be restored to its original shape. Furthermore, because the front member can be made thin, the impact when the front member hits an object is reduced, and the transport of the object can be stabilized.

[0010] (4) In the X-ray inspection apparatus according to any one of (1) to (3), the coefficient of friction of the surface of the front surface member may be smaller than the coefficient of friction of the X-ray shielding portion. With this configuration, it is possible to easily form the front surface member that is more shock-resistant or abrasion-resistant than the X-ray shielding member.

[0011] (5) In any one of the X-ray inspection devices (1) to (4) above, the front member may be suspended from the transport path, and the length of the front member extending from the base end fixed to the transport path to the tip end hanging down toward the transport unit may be shorter than the length of the X-ray shielding member extending from the base end to the tip end. In this configuration, the lower end of the X-ray shielding member can be configured to remain in contact with the transport unit while the lower end of the front member does not come into contact with the transport unit. As a result, it is possible to reduce wear on the lower end of the front member and prevent leakage of X-rays.

[0012] (6) The X-ray inspection device of (5) above may further include a rotation axis that rotatably fixes the X-ray shielding member and the front member, the rotation axis extending in a width direction perpendicular to both the conveying direction of the conveying section and the vertical direction in the conveying path, and a first stop member that is provided downstream of the rotation axis and maintains the front member in an inclined state so that the base end of the front member is located upstream of the tip end when viewed from the width direction, and that stops the front member from rotating upstream. In this configuration, the front member is initially pushed up by the first stop member, further improving the ease of passage of articles.

[0013] (7) The X-ray inspection apparatus of (6) may further include a second stop member that is provided downstream of the first stop member and that stops the front member from rotating downstream by more than a predetermined angle. This configuration can reduce the possibility of the front member rotating more than necessary and reducing the effect of suppressing X-ray leakage. [Effects of the Invention]

[0014] According to one aspect of the present invention, it is possible to prevent leakage of X-rays while reducing the risk of foreign matter being mixed into an item to be inspected. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a front view of an X-ray inspection apparatus according to an embodiment. [Figure 2] FIG. 2 is a side view of the X-ray inspection apparatus of FIG. [Figure 3] FIG. 3 is a front view showing the configuration of the transport unit and the shielding unit and its vicinity. [Figure 4] FIG. 4 is a perspective view of the downstream portion of the transport unit and the shielding unit as viewed obliquely from the downstream side. [Figure 5] FIG. 5 is a perspective view of the transport section and the downstream portion of the shielding unit as viewed obliquely from the upstream side. [Figure 6] Fig. 6(A) is a view of the downstream end of the transport unit and the shielding unit as seen from the upstream front, and Fig. 6(B) is a view of the downstream end of the transport unit and the shielding unit as seen from the downstream front. [Figure 7] Fig. 7(A) is a view of the downstream end of the transport unit and the shielding unit according to the modified example, as viewed from the upstream front side. Fig. 6(B) is a view of the downstream end of the transport unit and the shielding unit according to the modified example, as viewed from the downstream front side. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, one embodiment of the present invention will be described with reference to the drawings. In the description of the drawings, the same elements are given the same reference numerals, and duplicate explanations will be omitted. Furthermore, in this specification, "A or B" means that either A or B is included, and does not exclude the inclusion of both A and B.

[0017] 1 and 2, the X-ray inspection apparatus 1 includes an apparatus main body 2, support legs 3, and a transport unit (transport section) 5. The support legs 3 support the apparatus main body 2. The apparatus main body 2 has a housing 9 made of a material capable of blocking electromagnetic waves such as X-rays. The housing 9 includes, for example, an upper part 9a having a display operation section 8 provided on the front surface, a back part 9b extending in the vertical direction, and a lower part 9c protruding forward from the back part 9b.

[0018] The X-ray inspection apparatus 1 includes an inspection unit 15 incorporated in an apparatus main body 2. The inspection unit 15 has an inspection chamber (inspection area) 4 provided at approximately the center in the height direction of the apparatus main body 2. The inspection chamber 4 is provided with, for example, a shielding box (not shown). The inspection unit 15 includes an X-ray irradiation unit 6 and an X-ray detection unit 7 housed in a housing 9 of the apparatus main body 2. The X-ray irradiation unit 6 is arranged in an upper part 9a of the housing 9, and the X-ray detection unit 7 is arranged in a lower part 9c of the housing 9. The inspection unit 15 further includes a control unit 10 provided, for example, in the upper part 9a of the housing 9.

[0019] When viewed from the upstream side in the conveying direction A, the first wall 91 of the upper portion 9a, the second wall 92 of the back portion 9b, and the third wall 93 of the lower portion 9c form a U-shape that opens forward. The front of the housing 9, in which the conveying unit 5 is disposed, is covered by a shielding cover (not shown), which is opened and closed during maintenance, for example. The inspection chamber 4 is a substantially rectangular parallelepiped space surrounded by these walls and the shielding cover. A rectangular entrance opening 4a is formed at the upstream end of the inspection chamber 4 in the conveying direction A. A rectangular exit opening 4b is formed at the downstream end of the inspection chamber 4 in the conveying direction A. The shape and size of the entrance opening 4a are equal to the shape and size of the exit opening 4b. A conveying path 4c for the article G (see FIG. 3) is formed between the entrance opening 4a and the inspection chamber 4, and between the inspection chamber 4 and the exit opening 4b.

[0020] The transport unit 5 transports the article G in a transport direction A. The transport unit 5 is installed so as to pass through the inspection chamber 4 in the transport direction A. In other words, the inspection unit 15 is provided so as to cover the transport unit 5.

[0021] The X-ray inspection device 1 generates an X-ray transmission image of the item G while transporting the item G using the transport unit 5, and performs inspections of the item G (for example, inspection of the number of items stored, inspection of foreign matter contamination, inspection of missing items, inspection of cracks and chips, etc.) based on the X-ray transmission image. The transport unit 5 has an input section 20 arranged upstream in the transport direction A and an output section 30 arranged downstream in the transport direction A. The item G before inspection is transported into the inspection room 4 by the input section 20. The item G after inspection is transported out of the inspection room 4 by the output section 30. The item G determined to be defective by the X-ray inspection device 1 is sorted out of the production line by a sorting device (not shown) arranged downstream of the output section 30. The item G determined to be non-defective by the X-ray inspection device 1 passes through the sorting device as is.

[0022] The X-ray irradiator 6 irradiates X-rays (electromagnetic waves) onto the article G transported by the transport unit 5. The X-ray irradiator 6 includes, for example, an X-ray tube that emits X-rays and a collimator that spreads the X-rays emitted from the X-ray tube in a fan shape within a plane perpendicular to the transport direction A. The X-ray detector 7 detects the X-rays that have been irradiated by the X-ray irradiator 6 and transmitted through the article G. The X-ray detector 7 is configured as, for example, a line sensor. Specifically, the X-ray detector 7 includes a plurality of photodiodes that are arrayed one-dimensionally along a horizontal direction perpendicular to the transport direction A, and a scintillator that is arranged on the X-ray incident side of each photodiode. In this case, the X-ray detector 7 converts the X-rays incident on the scintillator into light, and the light incident on each photodiode is converted into an electrical signal.

[0023] The display operation unit 8 is provided on the upper part 9a of the housing 9 and faces forward. The display operation unit 8 displays various information (i.e., notifies the operator of the operating status) and accepts input of various conditions. The display operation unit 8 is, for example, a liquid crystal display, and displays an operation screen as a touch panel. In this case, the operator can input various conditions via the display operation unit 8. The display operation unit 8 notifies of various abnormalities in the X-ray inspection device 1. A notification light 11, which also functions as a notification unit, is provided on the upper part 9a of the housing 9.

[0024] The control unit 10 is disposed within the device main body 2. The control unit 10 controls the operation of each part of the X-ray inspection device 1. The control unit 10 is composed of a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), etc. Signals output from the X-ray detection unit 7 and subjected to A / D conversion are input to the control unit 10. The control unit 10 generates an X-ray transmission image of the item G based on the signal output from the X-ray detection unit 7, and functions as an inspection unit that inspects the item G based on the X-ray transmission image.

[0025] Each of the loading section 20 and the unloading section 30 has known components such as a motor, pulleys, timing belt, drive roller, and driven roller (all not shown). The transport unit 5 has a conveyor belt B installed throughout the loading section 20 and the unloading section 30, and causes the conveyor belt B to run at a predetermined speed. As a result, the conveyor unit 5 conveys the article G at that running speed. The movement speed (conveying speed) of the conveyor belt B is adjustable. The article G is conveyed on the conveying surface Ba of the conveyor belt B.

[0026] As shown in FIG. 3, the loading section 20 includes a frame 21 that supports the conveyor belt B via a pulley. The unloading section 30 includes a frame 31 that supports the conveyor belt B via a pulley. The frames 21 and 31 are made of a metal such as stainless steel. A small gap is formed between the frames 21 and 31 in the conveying direction A. An X-ray passage area X is formed through this gap, allowing X-rays to pass from the X-ray irradiator 6 to the X-ray detector 7. This gap, i.e., the passage area X, extends along the width direction D (see FIG. 2). The width direction D is a direction that intersects both the conveying direction A in the conveying unit 5 and the opposing direction (the up-down direction in FIG. 2) in which the X-ray irradiator 6 and the X-ray detector 7 face each other. In this embodiment, the conveying direction A and the width direction D are horizontal, and the opposing direction between the X-ray irradiator 6 and the X-ray detector 7 is the up-down direction (vertical).

[0027] 1 and 3, the inspection unit 15 inspects the article G by irradiating the article G with X-rays while the article G is traveling from the entrance opening 4a to the exit opening 4b. In the inspection unit 15, a shielding box and a shielding unit 40, which will be described later, prevent X-rays from leaking to the outside. The article G before inspection is carried into the inspection room 4 through the entrance opening 4a. The inspected article G is carried out of the inspection room 4 through the exit opening 4b.

[0028] The X-ray inspection apparatus 1 includes shielding units 40 that are provided at least at both the entrance opening 4a and the exit opening 4b and that block X-rays leaking to the outside from the entrance opening 4a and the exit opening 4b. The shielding units 40 will be described in detail below.

[0029] 1 and 3, the shielding unit 40 prevents X-rays irradiated onto the article G from leaking from the entrance opening 4a and the exit opening 4b of the inspection chamber 4. The shielding unit 40 has an upstream shielding unit 40A and a downstream shielding unit 40B. Since the upstream shielding unit 40A and the downstream shielding unit 40B have the same configuration, the following description will focus on the downstream shielding unit 40B, and will omit a description of the upstream shielding unit 40A.

[0030] As shown in Figures 4, 5, 6(A) and 6(B), the shielding unit 40B includes three sets of support shafts 43, a shielding plate (front member) 50, a shielding sheet (X-ray shielding member) 60, a first stop member 45, a second stop member 47, and a pair of partition walls 49, all of which have the same structure. The three sets of support shafts 43, the shielding plate 50, the shielding sheet 60, the first stop member 45 and the second stop member 47 are supported by a support frame 41. The support frame 41 is detachably fixed to the device body 2. The mounting position of the support frame 41 in the vertical direction relative to the device body 2 is adjustable.

[0031] The support shaft 43 extends in the width direction D. The support shaft 43 is inserted into holes formed in support frames 41 spaced apart in the width direction D, and is supported by the support frames 41. A shielding sheet 60 and a shielding plate 50 are rotatably suspended from the support shaft 43. The support shaft 43 is disposed above a conveying path 4c along which articles G are carried in and out of the inspection chamber 4.

[0032] The shielding sheet 60 is a flexible member that prevents X-rays from leaking from the transport path 4c. The shielding sheet 60 is formed, for example, from a resin member such as polyolefin or rubber containing tungsten that blocks X-rays. The shielding sheet 60 of this embodiment has a thickness of, for example, 0.1 mm to 3.0 mm. The shielding sheets 60 are arranged in the width direction D along the support shaft 43. In this embodiment, an example in which four shielding sheets 60 (shielding sheets 61, 62, 63, 64) are arranged will be described, but the number is not limited to four, and two, three, five or more shielding sheets may be provided, or only one shielding sheet 60 may be provided.

[0033] The width of the shielding sheet 60 in the width direction D can be set as appropriate. The end faces of adjacent shielding sheets 60 may contact each other without overlapping at their widthwise ends, or they may slightly overlap at their widthwise ends. The length of the shielding sheet 60 (the length from the base end on the side fixed to the conveying path 4c (the support shaft 43 side) to the tip on the side hanging down towards the conveying unit 5) is set so that the tip comes into contact with the conveying belt B of the conveying unit 5, or so that there is almost no gap between the tip and the conveying belt B.

[0034] The overall shape of the shielding sheet 60 composed of the shielding sheets 61, 62, 63, 64 may be such that both left and right ends 61a, 64a in the width direction D protrude downward and the central portion 60a is concave upward. More specifically, the left and right ends 61a, 64a protrude downward from the conveying surface Ba of the conveyor belt B in the conveying unit 5, and the central portion 60a faces the conveying surface Ba of the conveyor belt B with a slight gap therebetween.

[0035] The shielding plate 50 is disposed upstream of the shielding sheet 60 so as to overlap the shielding sheet 60, and is a member having higher impact resistance and abrasion resistance than the shielding sheet 60. The shielding plate 50 is formed of, for example, stainless steel, iron, or titanium. The shielding plate 50 of this embodiment has a thickness of 0.1 mm to 3.0 mm. The shielding plate 50 is a leaf spring and has elasticity. Furthermore, the coefficient of friction of the surface of the shielding plate 50 is smaller than the coefficient of friction of the surface of the shielding sheet 60.

[0036] The shielding plates 50 are arranged in the width direction D along the support shaft 43. In this embodiment, an example in which four shielding plates 50 (shielding plates 51, 52, 53, 54) are arranged will be described, but the number is not limited to four, and two, three, five or more shielding plates may be provided, or only one shielding plate 50 may be provided.

[0037] The width of the shielding plate 50 in the width direction D can be set appropriately. The end faces of adjacent shielding plates 50 may contact each other without overlapping at their widthwise ends, or they may slightly overlap at their widthwise ends. The length of the shielding plate 50 (the length from the base end on the side fixed to the conveying path 4c (the support shaft 43 side) to the tip on the side hanging down towards the conveying unit 5) is set so that the tip does not contact the conveying belt B of the conveying unit 5, or so that there is almost no gap between the tip and the conveying belt B.

[0038] In the present embodiment, the width of the shielding sheet 60 is the same as the width of the shielding plate 50, the width of the shielding sheet 60 is the same as the width of the shielding plate 50, and the number of shielding sheets 60 arranged in the width direction D is the same as the number of shielding plates 50 arranged in the width direction D. Furthermore, in the present embodiment, when the shielding unit 40B is viewed from the upstream side in the conveying direction A, the shielding sheet 60 is arranged so as to be just behind the shielding plate 50. That is, in the shielding unit 40B of the present embodiment, when the shielding unit 40B is viewed from the upstream side in the conveying direction A, the shielding sheet 60 does not protrude beyond the shielding plate 50 in the width direction. Furthermore, in the present embodiment, when the shielding unit 40B is viewed from the downstream side in the conveying direction A, the shielding plate 50 is arranged so as to be just behind the shielding sheet 60. That is, in the shielding unit 40B of the present embodiment, when the shielding unit 40B is viewed from the downstream side in the conveying direction A, the shielding plate 50 does not protrude beyond the shielding sheet 60 in the width direction. In addition, in the shielding unit 40B of this embodiment, the length of the shielding sheet 60 is longer than the length of the shielding plate 50.

[0039] The base ends of the shielding sheet 60 and the shielding plate 50 are rotatably (swingably) supported on the support shaft 43 via a first mounting member 43A and a second mounting member 43B. The first mounting member 43A is a plate-shaped member having a tubular portion through which the support shaft 43 is inserted. The second mounting member 43B is a plate-shaped member. The shielding sheet 60 and the shielding plate 50 are sandwiched between the two first mounting members 43A and the second mounting member 43B in a mutually overlapping state, and are thereby rotatably supported on the support shaft 43. The first mounting member 43A and the second mounting member 43B sandwich one shielding sheet 60 (shielding sheets 61, 62, 63, 64) and one shielding plate 50 (shielding plates 51, 52, 53, 54) that are overlapped with each other, using fastening members 43C such as bolts and nuts. As described above, the shielding sheet 60 and the shielding plate 50 are arranged in a stacked state, but there are no parts that are fixed to each other other than the part where the upper ends of the shielding sheet 60 and the shielding plate 50 are fixed to each other by being pressed against each other by the first mounting member 43A and the second mounting member 43B.

[0040] The first stop member 45 is provided downstream of the support shaft 43. The first stop member 45 is a rod-shaped member extending in the width direction D. When viewed from the width direction D, the first stop member 45 maintains the shielding plate 50 in an inclined state so that the base end is located upstream of the tip end, and restricts the rotation of the shielding sheet 60 and the shielding plate 50 toward the upstream side. The shielding sheet 60 and the shielding plate 50 are supported by the first stop member 45 so that they are inclined, for example, at an angle of 40 to 50 degrees (preferably 45 degrees) with respect to a vertical plane. Hereinafter, the angle α (see FIG. 3) of the shielding sheet 60 and the shielding plate 50 restricted by the first stop member 45 will be referred to as the restriction angle by the first stop member 45.

[0041] The first stop members 45 are inserted into elongated holes formed in the support frames 41 spaced apart in the width direction D, and are supported by the support frames 41. These elongated holes extend in the conveyance direction, allowing fine adjustment of the conveyance direction position of the first stop members 45. By adjusting the conveyance direction position of the first stop members 45, the restriction angles of the shielding sheet 60 and the shielding plate 50 can be adjusted.

[0042] The second stop member 47 is provided downstream of the first stop member 45. The second stop member 47 is a rod-shaped member extending in the width direction D. The second stop member 47 is inserted into round holes formed in the support frame 41 spaced apart in the width direction D, and is supported by the support frame 41. The second stop member 47 prevents the shielding sheet 60 and the shielding plate 50 from rotating downstream by more than a predetermined angle α (e.g., 80 degrees). More specifically, the shielding sheet 60 and the shielding plate 50 are supported on the support shaft 43 by the first stop member 45 and the second stop member 47 so that their tips can rotate freely at an angle α relative to the vertical direction within a range of, for example, 45 degrees to 70 degrees.

[0043] The shielding sheet 60 and the shielding plate 50 easily swing (lift up and rotate counterclockwise in the figure) when their leading ends come into contact with the article G being conveyed by the conveying unit 5, and return to their original reference position (a state in which the regulated angle is maintained) under their own weight after the article G has passed. With the shielding sheet 60 and the shielding plate 50 in this state, the second regulating member 47 regulates the shielding sheet 60 and the shielding plate 50, which are pushed out and rotated by the article G being conveyed by the conveying unit 5, from rotating by more than the predetermined angle α.

[0044] The pair of partition walls 49 are arranged at both left and right ends in the width direction D of the two downstream sets of support shafts 43, shielding plates 50, shielding sheets 60, first stop members 45, and second stop members 47 out of the three sets of support shafts 43, shielding plates 50, shielding sheets 60, first stop members 45, and second stop members 47. The pair of partition walls 49 are members that prevent leakage of X-rays. The pair of partition walls 49 are formed of a metal material such as stainless steel. The pair of partition walls 49 are arranged at the same position as the shielding sheet 60 in the conveying direction A or slightly downstream thereof. The pair of partition walls 49 are arranged at a distance in the width direction D that is slightly shorter than the length of the shielding sheet 60 in the width direction D. In other words, the partition wall 49 and the shielding sheet 60 may be arranged to overlap each other in the width direction D. Note that the partition wall 49 and the shielding sheet 60 may be arranged with a small gap between them in the width direction D.

[0045] The effects of the X-ray inspection device 1 of the above embodiment will be described. In the X-ray inspection device 1 of the above embodiment, the shielding plate 50 having impact resistance or abrasion resistance is provided upstream of the shielding sheet 60, so that the frequency with which the object G transported from the upstream side comes into direct contact with the shielding sheet 60 is reduced. This reduces the possibility of the shielding sheet 60 being damaged. As a result, it is possible to prevent leakage of X-rays. It is also possible to reduce the risk that a damaged shielding sheet 60 will become mixed in as a foreign object with the object G to be inspected. In other words, it is possible to reduce the risk of foreign objects becoming mixed in with the object G to be inspected. In particular, it is possible to obtain significant effects when inspecting an object G having corners.

[0046] The shielding plate 50 of the X-ray inspection apparatus 1 of the above embodiment is a thin plate-shaped leaf spring member made of a metal material. In this configuration, even if the shielding plate 50 is made thin and deformed by being hit by an object G, it can be restored to its original shape. Furthermore, because the shielding plate 50 can be made thin, the impact when the shielding plate 50 hits the object G is reduced, and the transport of the object G can be stabilized.

[0047] In the X-ray inspection apparatus 1 of the above embodiment, the coefficient of friction of the surface of the shielding plate 50 is smaller than the coefficient of friction of the shielding sheet 60. This makes it possible to easily form a shielding plate 50 that is more impact-resistant or abrasion-resistant than the shielding sheet 60.

[0048] In the X-ray inspection apparatus 1 of the above embodiment, the shielding plate 50 is suspended from the transport path 4c, and the length of the shielding plate 50 extending from the base end fixed to the transport path 4c to the tip end hanging down towards the transport unit 5 is shorter than the length of the shielding sheet 60 extending from the base end to the tip end. This makes it possible to configure the shielding plate 50 so that the bottom end of the shielding sheet 60 does not come into contact with the transport belt B of the transport unit 5, while keeping the bottom end of the shielding sheet 60 in contact with the transport belt B of the transport unit 5. As a result, it is possible to prevent leakage of X-rays while reducing wear on the bottom end of the shielding plate 50.

[0049] The X-ray inspection apparatus 1 of the above embodiment is provided with a first stop member 45 that maintains the shielding plate 50 in an inclined state so that the base end of the shielding plate 50 is located more upstream than the tip end when viewed in the width direction, and that restricts rotation toward the upstream side. That is, in the X-ray inspection apparatus 1 of the above embodiment, the shielding plate 50 and the shielding sheet 60 are maintained at a restricted angle. In the X-ray inspection apparatus 1 of the above embodiment, the shielding plate 50 and the shielding sheet 60 are initially pushed up by the first stop member 45, which further improves the passability of the article G.

[0050] More specifically, in the X-ray inspection apparatus 1 of the above embodiment, the object G transported by the transport unit 5 first comes into contact with the shielding sheet 60. In a conventional X-ray inspection apparatus provided with only a vertically hanging shielding sheet 60, the object G transported by the transport unit 5 comes into contact with the leading edge of the shielding sheet 60. As a result, a strong centrifugal force acts on the shielding sheet 60. This results in the shielding sheet 60 being turned up too much, and the impact on the object G is also large, increasing the risk of the object G tipping over. In contrast, in the X-ray inspection apparatus 1 of the above embodiment, when the shielding sheet 60 and the shielding plate 50 are in an inclined state, the object G comes into contact with a portion near the center in the longitudinal direction. Therefore, the centrifugal force acting on the shielding sheet 60 and the shielding plate 50 is small (i.e., the shielding sheet 60 and the shielding plate 50 are not turned up too much). In addition, the impact when the object G comes into contact with the shielding sheet 60 and the shielding plate 50 is also small, thereby reducing the risk of the object G tipping over. Furthermore, in the X-ray inspection apparatus 1 of the above embodiment, the leading edge of the shielding sheet 60 is in contact with the conveyor belt B, and therefore a frictional force acts, which can reduce excessive curling of the leading edge of the shielding sheet 60.

[0051] In the X-ray inspection apparatus 1 of the above embodiment, the second regulating member 47 restricts the shielding sheet 60 and the shielding plate 50 from rotating downstream by more than a predetermined angle. This reduces the possibility of the shielding sheet 60 and the shielding plate 50 rotating more than necessary and thereby reducing the effect of suppressing X-ray leakage. Furthermore, if the shielding sheet 60 and the shielding plate 50 rotate due to the object G, the transport path is opened to the outside, reducing the effect of suppressing X-ray leakage. For this reason, it is necessary to increase the transport interval of the object G in order to return the rotated state of the shielding sheet 60 and the shielding plate 50 to the reference position. In the X-ray inspection apparatus 1 of the above embodiment, the shielding sheet 60 and the shielding plate 50 are restricted from rotating more than necessary. This shortens the time it takes for the rotated state of the shielding sheet 60 and the shielding plate 50 to return to the reference position, thereby shortening the transport interval of the object G. As a result, the inspection capability of the X-ray inspection apparatus 1 can be improved.

[0052] Although one embodiment has been described above, one aspect of the present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the invention.

[0053] In the above embodiment, an example was given in which the shielding plate 50 has higher impact resistance or abrasion resistance than the shielding sheet 60, but the shielding plate 50 may also have higher impact resistance and abrasion resistance than the shielding sheet 60.

[0054] In the above embodiment and modified example, the shielding plate 50 has been described as being entirely made of a metal material, but this is not limiting. For example, the shielding plate 50 may be formed such that at least the outer surface thereof is made of a metal material. For example, the shielding plate 50 may be formed from a base material made of polyolefin, rubber, or the like, and a covering member that covers the entire outer surface of the base material or a portion of the outer surface that is expected to come into contact with the item G and is made of a metal material such as stainless steel, iron, or titanium. Even in this case, a shielding plate 50 that is more impact-resistant or abrasion-resistant than the shielding sheet 60 can be easily formed.

[0055] In the above embodiment and modified example, the shielding plates 50 and the shielding sheets 60 are formed in the same number and the same size, but this is not limiting. For example, even if they are the same size, they may be arranged offset from each other in the width direction, or different numbers may be arranged. For example, as shown in Figures 7(A) and 7(B), only the shielding sheet 60 may be sandwiched between two first mounting members 43A and a second mounting member 43B, the shielding sheet 60 may be suspended from the support shaft 43, and the shielding plate 50 may be attached to approximately the center of the shielding sheet 60 in the longitudinal direction.

[0056] In the above embodiment and modified example, the shielding unit 40 includes six sets of support shafts 43, shielding plates 50, shielding sheets 60, first regulating members 45 and second regulating members 47 having the same configuration as a whole, but the shielding unit 40A may include only one set of support shafts 43, shielding plates 50, shielding sheets 60, first regulating members 45 and second regulating members 47 provided at the entrance opening 4a, and the shielding unit 40B may include only one set of support shafts 43, shielding plates 50, shielding sheets 60, first regulating members 45 and second regulating members 47 provided at the exit opening 4b.

[0057] In the above embodiment and modified example, an example has been given in which six sets of support shafts 43, shielding plates 50, shielding sheets 60, first regulating members 45 and second regulating members 47 having the same configuration are arranged detachably on the device main body 2 via the support frame 41, but the mounting configuration is not limited, and may be fixed directly to the device main body 2, for example.

[0058] In the above embodiment and modified example, an example in which the first stop member 45 is provided has been described, but the first stop member 45 may be omitted. That is, the shielding plate 50 and the shielding sheet 60 do not have to be provided inclined with respect to the vertical plane. Furthermore, in addition to the first stop member 45, the second stop member 47 may also be omitted. Furthermore, an elastic member such as a coil spring or a torsion spring may be provided between the base end of the shielding plate 50 and the support shaft 43. Similarly, an elastic member such as a coil spring or a torsion spring may be provided between the base end of the shielding sheet 60 and the support shaft 43.

[0059] In the above embodiment and modified example, the shielding plate 50 has been described as being made of a material capable of blocking X-rays, but it may also be made of a material that cannot block X-rays as long as it has higher impact resistance or abrasion resistance than the shielding sheet 60.

[0060] In the above embodiment and the above modified example, an example in which a conveying unit 5 is provided has been described, but the shielding unit 40 may also be applied to an apparatus in which the shielding unit 40 is not used together with the conveying unit 5, for example, and the item G is manually introduced into the inspection room 4 by an operator.

[0061] In the above embodiment, an example was given in which the shielding sheet 60 and the shielding plate 50 are arranged in a state in which they are overlapped with no gaps between them (in close contact), but they may also be arranged with a small gap in the conveying direction A. [Explanation of symbols]

[0062] 1...X-ray inspection device, 4...inspection room (inspection area), 4c...conveying path, 5...conveying unit (conveying section), 6...X-ray irradiation section, 7...X-ray detection section, 10...control section (inspection section), 40...shielding unit, 40A...upstream shielding unit, 40B...downstream shielding unit, 41...support frame, 43...support shaft, 45...first control member, 47...second control member, 49...partition wall, 50 (51, 52, 53, 54)...shielding plate (front member), 60 (61, 62, 63, 64)...shielding sheet (X-ray shielding member), A...conveying direction, B...conveying belt, D...width direction, G...item.

Claims

1. a conveying unit that conveys the article; an X-ray irradiation unit that irradiates the object transported to the inspection area by the transport unit with X-rays; an X-ray detection unit that detects the X-rays that have passed through the article; an inspection unit that inspects the item based on the detection result of the X-ray detection unit; a flexible X-ray shielding member that prevents the X-rays from leaking from a transport path along which the article is carried into or out of the inspection area, the X-ray shielding member being suspended from the transport path; a front surface member that is arranged upstream of the X-ray shielding member so as to overlap with the X-ray shielding member, and that has higher impact resistance or abrasion resistance than the X-ray shielding member.

2. 2. The X-ray inspection apparatus according to claim 1, wherein at least an outer surface of the front member is made of a metal material.

3. 2. The X-ray inspection apparatus according to claim 1, wherein the front member is a thin plate-shaped leaf spring member made of a metal material.

4. 3. The X-ray inspection apparatus according to claim 1, wherein the coefficient of friction of the surface of the front member is smaller than the coefficient of friction of the X-ray shielding portion.

5. the front member is suspended from the transport path, 3. The X-ray inspection device according to claim 1, wherein a length of the front member extending from a base end fixed to the transport path to a tip end hanging down toward the transport unit is shorter than a length of the X-ray shielding member extending from the base end to the tip end.

6. a rotation shaft that rotatably fixes the X-ray shielding member and the front surface member, the rotation shaft extending in a width direction of the transport path that is perpendicular to both the transport direction of the transport section and a vertical direction; 6. The X-ray inspection apparatus according to claim 5, further comprising: a first stop member that is provided downstream of the rotation axis, that maintains the base end of the front member in an inclined state so that it is located upstream of the tip end when viewed in the width direction, and that stops the rotation toward the upstream side.

7. 7. The X-ray inspection apparatus according to claim 6, further comprising a second stop member provided downstream of the first stop member and configured to stop the front member from rotating downstream by more than a predetermined angle.

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