X-ray imaging device

Abstract

This X-ray imaging device comprises: a conveying unit (2) that includes a belt (7a) on which poultry thigh meat is placed and that conveys the poultry thigh meat; an X-ray imaging unit (11) that is provided above the conveying unit (2) and that irradiates the poultry thigh meat placed on the belt (7a) with X-rays; and a shielding unit (12) that is provided at the entrance and exit of the X-ray imaging unit (11) and that shields the X-rays of the X-ray imaging unit (11).

Description

X-ray imaging device

[0001] The present invention relates to an X-ray imaging device. This application claims priority based on Japanese Patent Application No. 2024-221652 filed on December 18, 2024, and incorporates its content herein by reference.

[0002] For example, an X-ray imaging device (X-ray bone detection unit) is used in a device (hereinafter referred to as a boning device) for boning boned chicken leg meat cut from the thigh bone of a chicken carcass (hereinafter simply referred to as chicken leg meat) (see, for example, Patent Document 1). In addition to the X-ray imaging device, this type of boning device includes a conveyor chain laid on a predetermined conveyance path, shackles provided at equal intervals on the conveyor chain for suspending the chicken leg meat, a cutting station for stripping the meat from the bone of the chicken leg meat, and an electric drive unit for driving the conveyor chain.

[0003] The X-ray imaging device is provided midway along the location where the conveyor chain is laid. The cutting station is provided on the downstream side in the conveyance direction of the conveyor chain from the X-ray imaging device among the locations where the conveyor chain is laid. The cutting station includes a cutter for stripping the meat around the bone of the chicken leg meat.

[0004] Under such a configuration, the joint position of the chicken leg meat is detected by the X-ray imaging device while the chicken leg meat suspended by the shackle is being conveyed by the conveyor chain. The detected joint position is aligned with the position of the cutter at the cutting station. After that, the meat around the bone of the chicken leg meat is stripped by the cutter, and the boning of the chicken leg meat is performed.

[0005] Here, the X-ray imaging device includes a protective housing to suppress leakage of X-rays to the outside. The X-ray imaging device lays a conveyor chain inside the protective housing and irradiates the chicken leg meat with X-rays inside the protective housing. Further, paddle wheels for shielding X-rays leaking from these entrances and exits to the outside are provided at the entrance and exit of the conveyor chain in the protective housing.

[0006] The paddle wheel has multiple paddle plates. The paddle wheel rotates in sync with the conveyor chain. The axis of rotation of the paddle wheel extends in the vertical direction. The shackle of the conveyor chain passes between two adjacent paddle plates in the circumferential direction of the rotating paddle wheel. This configuration allows the passage of poultry leg meat into the protective housing while shielding X-rays leaking to the outside from the inlet and outlet by the multiple paddle plates.

[0007] Japanese Patent No. 7123974

[0008] Furthermore, since the poultry thigh meat suspended from the shackle is supported at only one point, its posture is unstable. This sometimes resulted in a decrease in the accuracy of bone detection in the poultry thigh meat using the X-ray imaging device. In addition, the posture of the poultry thigh meat detected by the X-ray imaging device did not match the posture of the poultry thigh meat at the subsequent cutting station, leading to a decrease in the deboning yield of the poultry thigh meat. Moreover, the operator had to lift and suspend the poultry thigh meat to the shackle for transport, which increased the workload on the operator.

[0009] One aspect of the present invention provides an X-ray imaging apparatus that enables X-ray irradiation of a workpiece while stabilizing the workpiece's orientation during transport, and reduces the workload on the operator.

[0010] An X-ray imaging apparatus according to one aspect of the present invention comprises a transport unit having a mounting surface on which a workpiece is placed and transporting the workpiece; an X-ray imaging unit provided above the transport unit and irradiating the workpiece placed on the mounting surface with X-rays; and a shielding unit provided at the entrance and exit of the X-ray imaging unit and shielding the X-rays from the X-ray imaging unit.

[0011] This configuration allows the workpiece to be placed on the mounting surface of the transport unit, thus stabilizing the workpiece's posture during transport compared to conventional methods where the workpiece (e.g., poultry leg meat) is suspended from a shackle. Furthermore, since the workpiece is simply placed on the mounting surface, there is no need to lift the workpiece as in conventional methods, thus reducing the workload.

[0012] The workpiece is placed on the mounting surface, and then X-rays are irradiated onto the workpiece from above by the X-ray imaging unit, while the X-rays from the X-ray imaging unit are shielded by the shielding unit. This allows for X-ray irradiation of the workpiece while maintaining a stable position.

[0013] In the above configuration, the shielding portion comprises a rotating shaft that is rotatably supported and whose axis of rotation is in a direction intersecting the transport direction of the transporting portion and the normal direction of the mounting surface described above, a plurality of blades extending radially outward from the outer circumferential surface of the rotating shaft, and a drive unit that controls the rotational drive of the rotating shaft.

[0014] This configuration allows the workpiece to pass through the shielding section while reliably shielding X-rays leaking from the X-ray imaging device to the outside.

[0015] In the above configuration, the aforementioned mounting surface has a plurality of slits formed therein to avoid interference with the blades.

[0016] This configuration allows for avoidance of interference between the mounting surface and the blades through the slits, while minimizing the gap between the mounting surface and the blades. As a result, the shielding section can reliably block X-rays leaking from the entrance and exit of the X-ray imaging unit.

[0017] In the above configuration, a curtain portion that can be folded down relative to the blade is provided at the tip of the blade.

[0018] This configuration allows the transport and shielding units to be driven while the curtain unit is constantly in contact with the mounting surface. This minimizes the gap between the mounting surface and the blades (curtain unit). As a result, the shielding unit reliably blocks X-rays leaking from the entrance and exit of the X-ray imaging unit.

[0019] According to an X-ray imaging apparatus in one aspect of the present invention, it is possible to irradiate a workpiece with X-rays while stabilizing the workpiece's posture during transport, and to reduce the workload on the operator.

[0020] This is a schematic diagram of a poultry leg meat processing system in an embodiment of the present invention, viewed from above. This is a perspective view of an X-ray imaging device in an embodiment of the present invention. This is a plan view of the main part of the shielding unit in an embodiment of the present invention, viewed from the left and right directions. This is a perspective view of the drive unit in an embodiment of the present invention. This is a plan view of the drive unit in an embodiment of the present invention, viewed from above. This is an explanatory diagram showing the behavior of the shielding unit body in an embodiment of the present invention, where (a) to (d) show the orientation of the shielding unit body in order of behavior. This is a perspective view of the shielding unit body in a first modified example of the present invention. This is an explanatory diagram showing the behavior of the shielding unit body in a first modified example of the present invention, where (a) to (d) show the orientation of the shielding unit body in order of behavior. This is a plan view of the main part of the shielding unit in a second modified example of the present invention, viewed from the left and right directions. This is an explanatory diagram showing the behavior of the shielding unit in a second modified example of the present invention, where (a) to (d) show the orientation of the shielding unit in order of behavior.

[0021] Next, embodiments of the present invention will be described with reference to the drawings.

[0022] <Poultry Thigh Meat Processing System> Figure 1 is a schematic configuration diagram of a poultry thigh meat processing system 1 equipped with an X-ray imaging device 4 according to the present invention, viewed from above. As shown in Figure 1, the poultry thigh meat processing system 1 is a system that automatically debones poultry thigh meat (not shown). The poultry thigh meat processing system 1 is laid out in a long, one-way direction and includes a conveying section 2 for transporting poultry thigh meat. In the poultry thigh meat processing system 1, the input section 3, X-ray imaging device 4, sinewing device 5, and automatic deboning device 6 are arranged in this order from the upstream side in the conveying direction Y1 (see arrow Y1 in Figure 1) of the conveying section 2.

[0023] In the following explanation, the upstream side of the conveying direction Y1 will simply be referred to as the upstream side, and the downstream side of the conveying direction Y1 will simply be referred to as the downstream side. The vertical direction refers to the direction when the poultry leg meat processing system 1 is installed. The direction perpendicular to the conveying direction Y1 and the vertical direction will be referred to as the left-right direction. In the left-right direction, the central side in the short direction of the conveying section 2 will be referred to as the inside, and the side opposite the inside will be referred to as the outside.

[0024] <Conveying Section> The conveying section 2 includes a belt conveyor 7 and a chain conveyor 8. These belt conveyor 7 and chain conveyor 8 are arranged parallel to each other in the left-right direction. The belt conveyor 7 and chain conveyor 8 are driven synchronously. The chain conveyor 8 is provided with clamps 9 (see Figure 2, etc.) at equal intervals. The clamps 9 hold the ankles of poultry thighs (not shown) by hooking them onto the clamps 9. The poultry thighs held by the clamps 9 are placed on the belt 7a of the belt conveyor 7 in a lying position. That is, the belt 7a functions as a surface on which the poultry thighs are placed. The lying position of the poultry thighs refers to the position in which the poultry thighs are laid down with the inner thigh side facing upwards.

[0025] <Input Section> The input section 3 is equipped with a workbench 10 positioned parallel to the conveying section 2. The workbench 10 is positioned on the opposite side of the chain conveyor 8, with the belt conveyor 7 in between. Numerous poultry thighs (not shown) are fed onto the workbench 10. The worker picks up a poultry thigh from the workbench 10 and lays it on the belt 7a of the belt conveyor 7, hooking the ankle of the poultry thigh onto the clamper 9. In this way, the poultry thigh is fed into the poultry thigh processing system 1 via the input section 3.

[0026] <X-ray imaging device> The X-ray imaging device 4 irradiates the poultry leg meat being transported by the transport unit 2 with X-rays from above to acquire information on the shape of the bones in the poultry leg meat and the position and orientation of the bones relative to the entire poultry leg meat. Details of the X-ray imaging device 4 will be described later.

[0027] <Skewing Device> The skewing device 5 performs skewing along the bones of the poultry thigh meat based on information obtained by the X-ray imaging device 4 regarding the shape of the bones of the poultry thigh meat and the position and orientation of the bones relative to the entire poultry thigh meat. Since the poultry thigh meat is placed on the belt 7a, there is little change in the posture of the poultry thigh meat in the X-ray imaging device 4 and the posture of the poultry thigh meat in the skewing device 5. For this reason, the skewing device 5 can perform stable skewing.

[0028] <Automatic Deboning Device> The automatic deboning device 6 automatically removes and discharges the meat from the poultry thigh meat that has been scored by the scoring device 5. A transfer device 60 is provided between the automatic deboning device 6 and the conveying unit 2. This transfer device 60 transports the scored poultry thigh meat in front of the automatic deboning device 6 by the conveying unit 2, and then transfers the poultry thigh meat from the conveying unit 2 to the automatic deboning device 6.

[0029] <X-ray imaging device> Next, the details of the X-ray imaging device 4 will be described based on Figures 2 to 6. Figure 2 is a perspective view of the X-ray imaging device 4. In Figure 2, some covers have been removed to make the explanation easier to understand. As shown in Figures 1 and 2, the X-ray imaging device 4 comprises an X-ray imaging unit 11 provided above the transport unit 2, and a pair of shielding units 12 provided on the upstream and downstream sides of the X-ray imaging unit 11, respectively. The X-ray imaging unit 11 irradiates the poultry leg meat transported by the transport unit 2 with X-rays from above to acquire information on the shape of the bones of the poultry leg meat and the position and orientation of the bones relative to the entire poultry leg meat.

[0030] The X-ray imaging unit 11 comprises a housing 11a and an X-ray irradiation unit (not shown) housed within the housing 11a. Upstream and downstream of the housing 11a, inlets 11b and outlets 11c (hereinafter collectively referred to as inlets 11b and 11c) are formed to allow the passage of the transport unit 2 and the poultry leg meat transported by the transport unit 2. Shielding units 12 are provided to block these inlets 11b and 11c. Since each shielding unit 12 has the same configuration, the following description will only describe the shielding unit 12 located upstream of the X-ray imaging unit 11 (the same applies to the following modifications). The description of the shielding unit 12 located downstream of the X-ray imaging unit 11 will be omitted (the same applies to the following modifications).

[0031] Figure 3 is a plan view of the main part of the shielding section 12 as seen from the left and right directions. As shown in Figures 2 and 3, the shielding section 12 comprises a frame 13, a drive unit 15 partially supported by the frame 13, and a shielding section body 14 rotatably supported by the drive unit 15. The shielding section body 14 comprises a rotating shaft 16 rotatably supported by the drive unit 15, and a plurality of (four in this embodiment) blades 17 extending radially outward from the outer circumferential surface of the rotating shaft 16.

[0032] The rotating shaft 16 rotates around a rotation axis A in a direction parallel to the left and right, that is, a direction perpendicular to the conveying direction Y1 and the normal direction of the belt 7a. A pair of shielding plates 18 are provided on both sides of the rotating shaft 16 in the axial direction. The shielding plates 18 are plate-shaped members that extend along the longitudinal and vertical directions of the conveying section 2. The distance between the pair of shielding plates 18 is greater than the width in the left-right direction of the entrances and exits 11b and 11c of the X-ray imaging section 11. The pair of shielding plates 18 are positioned on both sides in the left-right direction of the entrances and exits 11b and 11c of the X-ray imaging section 11.

[0033] The blades 17 extend across the entire space between the pair of shielding plates 18 on the rotating shaft 16, and also extend radially along the rotating shaft 16. The blades 17 are arranged at equal intervals in the circumferential direction of the rotating shaft 16. In this embodiment, since there are four blades 17, the blades 17 are arranged at 90° intervals in the circumferential direction. The rotating shaft 16 is rotationally driven by a rotary actuator 21 of the drive unit 15, which will be described later. The direction of rotation of the rotating shaft 16 is such that the direction of movement of the blades 17 located below the center of the rotating shaft 16 (closer to the conveying unit 2) coincides with the conveying direction Y1 (see arrow CW in Figure 3, hereinafter simply referred to as the rotation direction CW).

[0034] The thickness of the blade 17 is sufficient to shield against X-rays. At both ends of the blade 17 in the left-right direction, bent portions 19 are formed on the upstream side in the rotational direction CW. Each bent portion 19 faces the corresponding shielding plate 18 in the left-right direction with a small gap between them. A flat portion 19b is formed at the tip 19a of the bent portion 19 opposite to the rotation axis 16. The flat portion 19b is formed on the upstream side in the rotational direction CW of the bent portion 19 (blade 17). The angle θ of the flat portion 19b with respect to the blade 17 is approximately 45°.

[0035] Figure 4 is a perspective view of the drive unit 15. Figure 5 is a plan view of the drive unit 15 from above. In Figures 4 and 5, some covers and frames 13 have been removed for clarity of explanation. As shown in Figures 2, 4, and 5, the drive unit 15 comprises a rotary actuator 21 and a vertical actuator 22. The rotary actuator 21 comprises a pair of pillow-type bearings 23 that rotatably support both sides of the rotation shaft 16 in the axial direction, and a rotary drive unit 24 provided on the left-right outer side of one of the pair of pillow-type bearings 23.

[0036] One axial end of the rotating shaft 16 protrudes outward in the left-right direction beyond the pillow block bearing 23. A rotary drive unit 24 is connected to this protruding portion. The rotary drive unit 24 comprises an electric motor 25 and a reduction unit 26 that reduces the rotation of the electric motor 25 and outputs the reduced speed. One end of the rotating shaft 16 is connected to the reduction unit 26. As a result, the rotating shaft 16 is rotationally driven by the rotary drive unit 24.

[0037] The vertical actuator 22 comprises a pair of linear motion mechanisms 31 supported on both sides of the frame 13 in the left-right direction, and a vertical drive unit 32 connected to one of the linear motion mechanisms 31. The pair of linear motion mechanisms 31 are equipped with base plates 33 fixed to both sides of the frame 13 in the left-right direction. Support plates 35 are fixed to the upper part of the base plates 33 via support columns 34 on the left-right outer side. Each support plate 35 is provided with a pillow block bearing 36. Both ends of a transmission shaft 37 are rotatably supported by each pillow block bearing 36. An upper pulley 38 is fitted and fixed to the transmission shaft 37 between the base plate 33 and the support plate 35. The upper pulley 38 and the transmission shaft 37 rotate together as a single unit.

[0038] A lower pulley 39 is rotatably supported at the lower part of the base plate 33. The lower pulley 39 and the upper pulley 38 are located on the same plane. The lower pulley 39 and the upper pulley 38 are arranged side by side in the vertical direction. A timing belt 41 is stretched between these lower pulley 39 and upper pulley 38. A slide bracket 42 is attached to the timing belt 41. The slide bracket 42 is formed in an L shape when viewed from the vertical direction. That is, the slide bracket 42 comprises a first plate 43 extending in the left-right direction, and a second plate 44 extending from the inside of the first plate 43 in the left-right direction along the transport direction Y1 and upstream.

[0039] The thickness direction of the first plate 43 coincides with the transport direction Y1. The thickness direction of the second plate 44 coincides with the left-right direction. Mounting plates 45 are provided on the left-right outer ends of the first plate 43. The mounting plates 45 are fastened and fixed to the first plate 43 by bolts 46. The timing belt 41 is sandwiched between the first plate 43 and the mounting plates 45. The surface of the mounting plates 45 that overlaps with the timing belt 41 is formed in an uneven shape. As a result, the mounting plates 45 bite into the timing belt 41, and the slide bracket 42 moves together with the timing belt 41.

[0040] The second plate 44 is supported by a linear guide 47 provided on the frame 13. The linear guide 47 extends in the vertical direction. This restricts the movement direction of the slide bracket 42 to only the vertical direction. The upstream end of each second plate 44 beyond the linear guide 47 is fastened and fixed to the corresponding pillow block bearing 23 of the rotary actuator 21. That is, the rotation axis 16 of the shielding body 14 is supported by the slide bracket 42 via the pillow block bearing 23 of the rotary actuator 21.

[0041] The vertical drive unit 32 is located on the left-right outer side of one of the pair of linear motion mechanisms 31. One end of the transmission shaft 37 in the linear motion mechanism 31 protrudes outward in the left-right direction from the pillow block bearing 36. The vertical drive unit 32 is connected to this protruding portion. The vertical drive unit 32 includes an electric motor 48 and a reduction unit 49 that reduces the rotation of the electric motor 48 and outputs the reduced speed. For example, a servo motor is used as the electric motor 48. One end of the transmission shaft 37 is connected to the reduction unit 49. However, it is not limited to this, and various motors can be used.

[0042] Under this configuration, the transmission shaft 37 is rotationally driven by the vertical drive unit 32. The transmission shaft 37 repeatedly rotates in forward and reverse directions within a certain range of rotational angles under the drive control of the vertical drive unit 32. As a result, the upper pulley 38 repeatedly rotates in forward and reverse directions in conjunction with the rotation of the transmission shaft 37. Furthermore, the timing belt 41 also repeatedly rotates in forward and reverse directions.

[0043] The rotational motion of the timing belt 41 is converted into vertical linear motion by the slide bracket 42. As a result, the shielding body 14 repeatedly moves up and down within a certain range via the rotary actuator 21. That is, the shielding body 14 rotates around the rotation axis 16 by the rotary actuator 21 while repeatedly moving up and down within a certain range by the vertical actuator 22. The behavior of the shielding body 14 will be described in detail below.

[0044] <Regarding the behavior of the shielding part main body> Next, based on FIG. 6, the behavior of the shielding part main body 14 will be described in detail. FIG. 6 is an explanatory diagram showing the behavior of the shielding part main body 14, and (a) to (d) show the postures of the shielding part main body 14 in the order of behavior. FIGS. 6(a) to 6(d) are plan views of the shielding part main body 14 viewed from the left-right direction and correspond to FIG. 3 described above.

[0045] As shown in FIGS. 6(a) to 6(d), the drive unit 15 rotates and vertically moves the rotary shaft 16 in synchronization with the conveyance unit 2. More specifically, as shown in FIG. 6(a), when the extending direction of the blade 17 viewed from the left-right direction is along the normal direction of the belt 7a, the drive unit 15 separates the rotary shaft 16 from the conveyance unit 2 the most. In other words, when the extending direction of the blade 17 viewed from the left-right direction is along the vertical direction, the position of the rotary shaft 16 is at the top dead center. In this state, a slight gap is formed between the tip 19a of the blade 17 and the belt 7a.

[0046] Subsequently, as shown in FIG. 6(b), as the conveyance unit 2 and the rotary shaft 16 are driven in synchronization, the clamp 9 (edible chicken thigh meat) enters between the blades 17 adjacent in the circumferential direction. At this time, since the blade 17 inclines with respect to the vertical direction (the normal direction of the belt 7a), the tip 19a of the blade 17 tends to separate from the belt 7a by this amount. However, by the drive unit 15, the rotary shaft 16 slides downward while rotating (see the arrow Y2 in FIG. 6(b)). As a result, the gap between the tip 19a of the blade 17 and the belt 7a is kept constant. At this time, a flat portion 19b is formed on the tip 19a of the blade 17 on the upstream side in the rotation direction CW. Therefore, without the bent portion 19 of the blade 17 interfering with the belt 7a, the gap between the tip 19a of the blade 17 and the belt 7a is kept constant.

[0047] As shown in FIG. 6(c), the drive unit 15 brings the rotary shaft 16 closest to the conveying unit 2 when the extending direction of the blade 17 as viewed from the left-right direction is along a direction 45° with respect to the normal direction of the belt 7a. In other words, when the extending direction of the blade 17 as viewed from the left-right direction is along a direction 45° with respect to the up-down direction, the position of the rotary shaft 16 is at the bottom dead center. In this state, the periphery of the clamp 9 is surrounded by the blades 17 and the belt 7a adjacent to each other in the circumferential direction.

[0048] After that, as shown in FIG. 6(d), the rotary shaft 16 slides upward while rotating by the drive unit 15 (see arrow Y3 in FIG. 6(d)). For this reason, while keeping the gap between the tip 19a of the blade 17 and the belt 7a constant, the clamp 9 moves so as to be discharged from between the blades 17 adjacent to each other in the circumferential direction. In this way, the X-ray of the X-ray imaging unit 11 is surely shielded by the shielding unit 12.

[0049] As described above, the X-ray imaging apparatus 4 includes a conveying unit 2 having a belt 7a, an X-ray imaging unit 11 provided above the conveying unit 2, and shielding units 12 provided at the entrances and exits 11b, 11c of the X-ray imaging unit 11. The belt 7a functions as a placement surface for placing the edible bird leg meat. In this way, since the edible bird leg meat is placed on the belt 7a, the posture of the edible bird leg meat during conveyance can be stabilized as compared with the case of suspending the edible bird leg meat by a shackle as in the prior art. Further, since the edible bird leg meat is only placed on the belt 7a, there is no need to lift the edible bird leg meat as in the prior art, and the work load can be reduced.

[0050] After placing the edible bird leg meat on the belt 7a of the conveying unit 2, the edible bird leg meat is irradiated with X-rays from above by the X-ray imaging unit 11, and the X-rays of the X-ray imaging unit 11 are shielded by the shielding unit 12. For this reason, it is possible to irradiate the edible bird leg meat with X-rays while stabilizing the posture of the edible bird leg meat.

[0051] In the above configuration, the shielding unit 12 comprises a rotating shaft 16, a plurality of blades 17, and a drive unit 15 that controls the rotation of the rotating shaft 16 around the rotation axis A. Therefore, the rotating shielding unit body 14 can receive poultry leg meat between adjacent blades 17 in the circumferential direction and discharge the poultry leg meat from between adjacent blades 17 in the circumferential direction. In this way, while allowing poultry leg meat to pass through the shielding unit 12, the shielding unit 12 can reliably shield X-rays leaking from the X-ray imaging device 4 to the outside.

[0052] Furthermore, the drive unit 15 moves the rotating shaft 16 closer to and further away from the conveying unit 2. Therefore, the distance between the conveying unit 2 and the rotating shaft 16 is changed according to the position of the blades 17, ensuring that the gap between the belt 7a and the tip 19a of the blades 17 remains constant. Thus, the shielding unit 12 reliably shields X-rays leaking from the X-ray imaging device 4 to the outside, making it possible to more reliably irradiate the poultry thighs with X-rays even when a belt conveyor 7 is used for conveying poultry thighs.

[0053] The drive unit 15 rotates the rotating shaft 16 in synchronization with the conveying unit 2 and also moves it up and down. This ensures that the poultry thigh meat passes reliably between two adjacent blades 17 in the circumferential direction. This prevents the poultry thigh meat from coming into contact with the blades 17, thus stabilizing the quality of the poultry thigh meat.

[0054] The drive unit 15 positions the rotating shaft 16 furthest from the conveying unit 2 when the extension direction of the blades 17, as viewed from the left and right, is aligned with the normal direction of the belt 7a. This minimizes the gap between the belt 7a and the blades 17 and prevents contact between the conveying unit 2 and the shielding unit 12.

[0055] In this embodiment, there are four blades 17. With this configuration, the drive unit 15 brings the rotating shaft 16 closest to the conveying unit 2 when the extension direction of the blades 17, as viewed from the left and right, is aligned with a direction 45° to the normal direction of the belt 7a. This minimizes the gap between the belt 7a and the blades 17 and prevents contact between the conveying unit 2 and the shielding unit 12. An appropriate size can be secured for the spacing between two adjacent blades 17 in the circumferential direction, and the poultry leg meat (clamper 9) can be reliably passed between two adjacent blades 17 in the circumferential direction.

[0056] A flat portion 19b is formed at the tip 19a of the feather 17. Because of the flat portion 19b, when poultry leg meat is placed between two adjacent feathers 17 in the circumferential direction, these two feathers 17 can be brought as close to the belt 7a as possible without interfering with the belt 7a. As a result, the shielding portion 12 can more reliably shield X-rays leaking from the X-ray imaging device 4 to the outside.

[0057] The drive unit 15 comprises a linear motion mechanism 31 and an electric motor 48 connected to the linear motion mechanism 31. In this way, the rotating shaft 16 can be moved closer to and further away from the belt 7a with a simple structure. This makes it possible to reduce the manufacturing cost of the X-ray imaging device 4.

[0058] In the above-described embodiment, the case in which the vertical actuator 22 comprises a linear motion mechanism 31 and a vertical drive unit 32 was explained. The case in which the rotating shaft 16 (shielding body 14) slides up and down by the vertical actuator 22 was explained. However, it is not limited to this, and the vertical actuator 22 can be configured to move the rotating shaft 16 closer to or further away from the transport unit 2. The vertical actuator 22 does not have to slide the rotating shaft 16 perfectly along the vertical direction.

[0059] In the above embodiment, a case was described in which the X-ray imaging device 4 is provided with a drive unit 15 that moves the rotating shaft 16 closer to and further away from the transport unit 2. This case was described in which the gap between the tip 19a of the blade 17 and the belt 7a is kept constant, and X-rays leaking from the X-ray imaging device 4 to the outside are reliably shielded. However, it is not limited to this, and it is sufficient if the shielding unit body 14 can shield X-rays leaking from the inlets and outlets 11b and 11c of the X-ray imaging unit 11. Modifications will be described below.

[0060] [First Modified Example] Figure 7 is a perspective view of the shielding body 14 in the first modified example. As shown in Figure 7, the blades 17 of the shielding body 14 are provided with a plate-shaped curtain portion 51 at the tip 17a opposite to the rotation axis 16. The curtain portion 51 is connected to the blades 17, for example, via a plurality of hinges 52. As a result, the curtain portion 51 is rotatably mounted on the upstream side of the blades 17 in the rotation direction CW.

[0061] In the first modified example, the drive unit 15 does not have a vertical actuator 22 (see Figure 4). That is, the drive unit 15 only rotates the rotation shaft 16 at a constant height. The height of the rotation shaft 16 is the height at which the curtain portion 51 contacts the belt 7a when the extension direction of the blades 17, as viewed from the left and right, is aligned with the normal direction of the belt 7a. That is, when the extension direction of the blades 17, as viewed from the left and right, is aligned with the normal direction of the belt 7a, the curtain portion 51 is in contact with the belt 7a and rotated (bent) relative to the blades 17. This rotation direction (bending direction) is upstream of the rotation direction CW.

[0062] Next, the behavior of the shielding body 14 (curtain portion 51) in the first modified example will be described in detail based on Figure 8. Figure 8 is an explanatory diagram showing the behavior of the shielding body 14, and (a) to (d) show the posture of the shielding body 14 in order of behavior. Figures 8(a) to 6(d) are plan views of the shielding body 14 as seen from the left and right directions.

[0063] As shown in Figure 8(a), when the extension direction of the blades 17 viewed from the left and right directions is aligned with the normal direction of the belt 7a, the curtain portion 51 of the shielding body 14 contacts the belt 7a and the curtain portion 51 is bent relative to the blades 17. Subsequently, as shown in Figure 8(b), the conveying unit 2 and the rotating shaft 16 are driven in synchronously, causing the clamper 9 (poultry leg meat) to enter between adjacent blades 17 in the circumferential direction. The shielding body 14 (rotating shaft 16) rotates with the curtain portion 51 still in contact with the belt 7a. Since the curtain portion 51 is rotatably provided on the upstream side of the rotation direction CW relative to the blades 17, the rotation of the shielding body 14 is not hindered.

[0064] As shown in Figure 8(c), when the extension direction of the blade 17, as viewed from the left and right, is aligned with a direction 45° to the normal direction of the belt 7a, one of the two adjacent curtain sections 51 in the circumferential direction comes into contact with the belt 7a. In this state, the upstream side of the clamper 9 is shielded by the upstream blade 17 and curtain section 51 and the belt 7a.

[0065] Subsequently, as shown in Figure 8(d), when the shielding body 14 rotates further, the clamper 9 moves so that it is discharged from between adjacent vanes 17 in the circumferential direction. In this way, no gap is formed between the belt 7a and the curtain portion 51. One of the four curtain portions 51 is always in contact with the belt 7a. Therefore, according to the first modification described above, the same effects as the embodiment described above can be achieved.

[0066] In the first modification described above, the case in which the curtain portion 51 is connected to the blade 17 via, for example, a plurality of hinges 52 was explained. This described a case in which the curtain portion 51 is rotatably mounted on the upstream side of the rotational direction CW relative to the blade 17. However, it is not limited to this, and it is sufficient that the curtain portion 51 is foldably mounted on the upstream side of the rotational direction CW relative to the blade 17. For example, the curtain portion 51 may be configured to bend relative to the blade 17.

[0067] [Second Modification] Figure 9 is a plan view of the main part of the shielding part 12 in the second modification, viewed from the left and right directions. Figure 9 corresponds to Figure 3 described above. In the second modification, as with the first modification described above, the drive unit 15 does not have a vertical actuator 22 (see Figure 4). That is, the drive unit 15 only rotates the rotation shaft 16 at a constant height. As shown in Figure 9, the difference between the first modification and the second modification described above is that in the first modification, a curtain part 51 is provided on the blade 17, whereas in the second modification, a curtain part 51 is not provided on the blade 17.

[0068] In the second modification, since the curtain portion 51 is not provided, the extension length of the blade 17 is the same as the length of the blade 17 with the curtain portion 51 provided in the first modification. Also, in the second modification, a slit 53 is formed in the belt 7a at the location corresponding to the blade 17. The tip 17a of the blade 17 is inserted into this slit 53 while the conveying unit 2 and the rotating shaft 16 are driven in sync. In order to form the slit 53, the belt 7a may be formed from multiple plates or blocks.

[0069] Next, the behavior of the shielding portion 12 in the second modified example will be described in detail based on Figure 10. Figure 10 is an explanatory diagram showing the behavior of the shielding portion 12, and (a) to (d) show the orientation of the shielding portion 12 in order of behavior. Figures 10(a) to 10(d) are plan views of the shielding portion 12 viewed from the left and right directions, and correspond to the aforementioned Figure 9.

[0070] As shown in Figure 10(a), when the extension direction of the blades 17 viewed from the left and right directions is aligned with the normal direction of the belt 7a, the tip 17a of the blades 17 is inserted into the slit 53 of the belt 7a. Subsequently, as shown in Figure 10(b), the conveying unit 2 and the rotating shaft 16 are driven in synchronously, causing the clamper 9 (poultry leg meat) to enter between adjacent blades 17 in the circumferential direction. The shielding unit body 14 (rotating shaft 16) rotates with the tip 17a of the blades 17 still inserted into the slit 53 of the belt 7a.

[0071] As shown in Figure 10(c), when the extension direction of the blades 17 viewed from the left and right directions is aligned with a direction 45° to the normal direction of the belt 7a, the position of the belt 7a and the position of the tip 17a of the blades 17 lie on the same plane. In this state, the clamper 9 is surrounded by adjacent blades 17 and belt 7a in the circumferential direction.

[0072] Subsequently, as shown in Figure 10(d), when the shielding body 14 rotates further, the clamper 9 moves so that it is discharged from between adjacent vanes 17 in the circumferential direction. Therefore, according to the second modified example described above, the shielding body 12 can shield X-rays leaking from the inlets and outlets 11b and 11c of the X-ray imaging unit 11. This prevents the X-rays from leaking to the input unit 3 or the grooving device 5.

[0073] The present invention is not limited to the embodiments and modifications described above, but includes various modifications to the embodiments and modifications described above without departing from the spirit of the invention. For example, in the embodiments and modifications described above, the X-ray imaging device 4 was described in the case where it is used in the poultry leg meat processing system 1. However, the invention is not limited to this, and the X-ray imaging device 4 can be used in processing systems for various workpieces other than poultry leg meat.

[0074] In the embodiments and modifications described above, the case in which four blades 17 are provided was explained. However, the invention is not limited to this, and the number of blades 17 can be any number that can constantly shield X-rays from the X-ray imaging unit 11. The vertical actuator 22 should be driven according to the number of blades 17. In the second modification, slits 53 can be formed in the belt 7a according to the number of blades 17.

[0075] 2...Conveyor unit 4...X-ray imaging device 7a...Belt (mounting surface) 11...X-ray imaging unit 11b...Inlet 11c...Outlet 12...Shielding unit 15...Drive unit 16...Rotating shaft 17...Blades 51...Curtain unit 53...Slit

Claims

1. An X-ray imaging apparatus comprising: a transport unit having a mounting surface on which a workpiece is placed and transporting the workpiece; an X-ray imaging unit provided above the transport unit and irradiating the workpiece placed on the mounting surface with X-rays; and a shielding unit provided at the entrance and exit of the X-ray imaging unit and shielding the X-rays from the X-ray imaging unit.

2. The X-ray imaging apparatus according to claim 1, wherein the shielding portion is rotatably supported and comprises: a rotating shaft whose axis of rotation is in a direction intersecting the transport direction of the transport portion and the normal direction of the mounting surface described above; a plurality of blades extending radially outward from the outer circumferential surface of the rotating shaft; and a drive unit for controlling the rotational drive of the rotating shaft.

3. The mounting surface has a plurality of slits formed therein to avoid interference with the blades, as described in claim 2.

4. The X-ray imaging apparatus according to claim 2, wherein the tip of the blade is provided with a curtain portion that can be folded relative to the blade.

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