X-ray imaging device

Abstract

This X-ray imaging device comprises: a conveyance unit (2) that has a belt (7a) on which poultry thigh meat is placed and conveys the poultry thigh meat; an X-ray imaging unit (11) that is provided above the conveyance unit (2) and irradiates the poultry thigh meat placed on the belt (7a) with X-rays; and a shielding unit (12) that is provided at the entrance / exit of the X-ray imaging unit (11) and shields the X-rays of the X-ray imaging unit (11). The shielding unit (12) comprises: a rotary shaft (16) that is rotatably supported and has a rotation axis (A) in a direction intersecting the conveyance direction (Y1) of the conveyance unit (2) and the normal direction of the belt (7a); a plurality of blades (17) that extend outward in the radial direction from the outer peripheral surface of the rotary shaft (16); and a drive unit (15) that rotates the rotary shaft (16) and moves the rotary shaft (16) up and down to bring the rotary shaft (16) toward or away from the conveyance unit (2) according to the rotational positions of the blades (17).

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. 2024-221639 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 poultry leg meat cut from the thigh bone of a poultry carcass (hereinafter simply referred to as poultry 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 poultry leg meat, a cutting station for stripping the meat from the bone of the poultry 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 poultry leg meat.

[0004] Under such a configuration, the joint position of the poultry leg meat is detected by the X-ray imaging device while the poultry 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 poultry leg meat is stripped by the cutter, and the boning of the poultry 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 poultry 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 device that enables X-ray irradiation of a workpiece (e.g., poultry leg meat) while maintaining a stable posture during transport, and that 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, wherein the shielding unit is rotatably supported and has a rotation axis whose rotation axis is in a direction intersecting the transport direction of the transport unit and the normal direction of the mounting surface; a plurality of vanes extending radially outward from the outer circumferential surface of the rotation axis; and a drive unit that rotates the rotation axis and moves the rotation axis up and down to move it closer to and further away from the transport unit according to the rotation position of the vanes.

[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 the conventional method of suspending the workpiece from a shackle. Furthermore, since the workpiece is simply placed on the mounting surface, there is no need to lift the workpiece as in the conventional method, thus reducing the workload.

[0012] Here, if the X-ray imaging unit is placed above the transport unit which has a mounting surface, simply rotating a paddle wheel as in the conventional method will create a gap between the mounting surface of the transport unit and the shielding unit to block the X-rays. In other words, depending on the rotation position of the paddle wheel, a large gap may be created between the mounting surface of the transport unit and the shielding unit. As a result, it is not possible to shield X-rays leaking from the X-ray imaging device to the outside.

[0013] Therefore, as described above, the shielding section is composed of a rotating shaft, multiple blades, and a drive unit that moves the rotating shaft closer to and further away from the conveying section. With this configuration, the distance between the conveying section and the rotating shaft can be changed according to the position of the blades, and the gap between the mounting surface and the blades can always be kept constant. As a result, the shielding section can block X-rays leaking from the X-ray imaging device to the outside, making it possible to irradiate the workpiece with X-rays.

[0014] In the above configuration, the drive unit rotates the rotating shaft and moves it up and down in synchronization with the transport unit.

[0015] This configuration ensures that the workpiece can reliably pass between two adjacent blades in the circumferential direction. This prevents the workpiece from coming into contact with the blades, thus stabilizing the quality of the workpiece.

[0016] In the above configuration, the drive unit separates the rotating shaft from the transport unit as far as possible when the extension direction of the blades is aligned with the direction normal to the mounting surface described above.

[0017] This configuration minimizes the gap between the mounting surface and the blades, and prevents contact between the conveying section and the shielding section.

[0018] In the above configuration, the number of blades is four, and the drive unit brings the rotating shaft closest to the transport unit when the extension direction of the blades is aligned with a direction 45° to the normal direction of the mounting surface described above.

[0019] This configuration minimizes the gap between the mounting surface and the blades, and prevents contact between the conveying section and the shielding section. It ensures an appropriate spacing between two adjacent blades in the circumferential direction, and allows the workpiece to pass reliably between the two adjacent blades.

[0020] In the above configuration, a chamfered portion is formed on the tip of the blade opposite to the rotation axis, on the upstream side in the rotational direction of the rotation axis.

[0021] This configuration allows the chamfered portion to be formed, and when a workpiece is positioned between two adjacent blades in the circumferential direction, these two blades can be brought as close as possible to the mounting surface. As a result, the shielding portion can more reliably shield X-rays leaking from the X-ray imaging device to the outside.

[0022] In the above configuration, the drive unit comprises a motor and a linear motion mechanism that converts the rotational motion of the motor into linear motion and transmits it to the rotating shaft.

[0023] This configuration allows the axis of rotation to be moved closer to or further away from the mounting surface with a simple structure.

[0024] 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.

[0025] 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.

[0026] Next, embodiments of the present invention will be described with reference to the drawings.

[0027] <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.

[0028] 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 up and down directions refer to the state when the poultry leg meat processing system 1 is installed. The direction perpendicular to the conveying direction Y1 and the up and down direction will be referred to as the left and right direction. In the left and 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.

[0029] <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.

[0030] <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.

[0031] <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.

[0032] <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.

[0033] <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.

[0034] <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.

[0035] 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).

[0036] 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.

[0037] 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.

[0038] 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).

[0039] 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°.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] A lower pulley 39 is rotatably supported at the lower part of a base plate 33. The lower pulley 39 and an 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 looped around the lower pulley 39 and the 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 includes a first plate 43 extending in the left-right direction and a second plate 44 extending along the conveyance direction Y1 and upstream from the inner side in the left-right direction of the first plate 43.

[0044] The thickness direction of the first plate 43 coincides with the conveyance direction Y1. The thickness direction of the second plate 44 coincides with the left-right direction. Mounting plates 45 are provided at the outer ends in the left-right direction 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 plate 45 that overlaps with the timing belt 41 is formed in a concavo-convex shape. Thereby, the mounting plate 45 bites into the timing belt 41, and the slide bracket 42 is moved integrally with the timing belt 41.

[0045] The second plate 44 is supported by a linear guide 47 provided on a frame 13. The linear guide 47 extends in the vertical direction. Thereby, the moving direction of the slide bracket 42 is restricted only to the vertical direction. The end of each second plate 44 on the upstream side of the linear guide 47 is fastened and fixed to a corresponding pillow-shaped bearing 23 of a rotary actuator 21. That is, the rotating shaft 16 of the shielding part main body 14 is supported by the slide bracket 42 via the pillow-shaped bearing 23 of the rotary actuator 21.

[0046] The vertical drive unit 32 is provided outside the left and right directions 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 and right directions from the spherical 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 speed reduction unit 49 that reduces and outputs the rotation of the electric motor 48. As the electric motor 48, for example, a servo motor is used. One end of the transmission shaft 37 is connected to the speed reduction unit 49. However, it is not limited to this, and various motors can be adopted.

[0047] Under such a configuration, the transmission shaft 37 is rotationally driven by the vertical drive unit 32. The transmission shaft 37 repeats forward and reverse rotations within a certain range of rotation angles under the drive control of the vertical drive unit 32. Then, the upper pulley 38 repeats forward and reverse rotations integrally with the rotation of the transmission shaft 37. Furthermore, the timing belt 41 repeats forward and reverse rotations.

[0048] The rotational motion of the timing belt 41 is converted into a linear motion in the vertical direction by the slide bracket 42. Thereby, the shielding unit main body 14 repeats vertical movement within a certain range via the rotary actuator 21. That is, the shielding unit main body 14 repeats vertical movement within a certain range by the vertical movement actuator 22 while rotating around the rotation shaft 16 by the rotary actuator 21. Hereinafter, the behavior of the shielding unit main body 14 will be described in detail.

[0049] <Regarding the behavior of the shielding unit main body> Next, based on FIG. 6, the behavior of the shielding unit main body 14 will be described in detail. FIG. 6 is an explanatory diagram showing the behavior of the shielding unit main body 14, and (a) to (d) show the postures of the shielding unit main body 14 in the order of behavior. FIGS. 6(a) to 6(d) are plan views of the shielding unit main body 14 viewed from the left and right directions, corresponding to FIG. 3 described above.

[0050] As shown in Figures 6(a) to 6(d), the drive unit 15 rotates and moves the rotating shaft 16 up and down in synchronization with the conveying unit 2. More specifically, as shown in Figure 6(a), the drive unit 15 moves the rotating shaft 16 furthest away 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. In other words, when the extension direction of the blades 17, as viewed from the left and right, is aligned with the vertical direction, the position of the rotating shaft 16 is at top dead center. In this state, only a small gap is formed between the tip 19a of the blades 17 and the belt 7a.

[0051] Next, as shown in Figure 6(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. At this time, the blades 17 tilt with respect to the vertical direction (normal direction of the belt 7a), so the tip 19a of the blade 17 tries to move away from the belt 7a. However, the rotating shaft 16 slides downward while being rotated by the drive unit 15 (see arrow Y2 in Figure 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 upstream side of the tip 19a of the blade 17 in the rotation direction CW. Therefore, the bent portion 19 of the blade 17 does not interfere with the belt 7a, and the gap between the tip 19a of the blade 17 and the belt 7a is kept constant.

[0052] As shown in Figure 6(c), 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 directions, is aligned at a 45° angle with respect to the normal direction of the belt 7a. In other words, when the extension direction of the blades 17, as viewed from the left and right directions, is aligned at a 45° angle with respect to the up and down direction, the position of the rotating shaft 16 is at its bottom dead center. In this state, the clamper 9 is surrounded by adjacent blades 17 and the belt 7a in the circumferential direction.

[0053] Subsequently, as shown in Figure 6(d), the drive unit 15 causes the rotating shaft 16 to rotate and slide upward (see arrow Y3 in Figure 6(d)). This movement ensures that the clamper 9 is discharged from between adjacent blades 17 in the circumferential direction, while maintaining a constant gap between the tip 19a of the blades 17 and the belt 7a. In this way, the shielding unit 12 reliably shields the X-rays from the X-ray imaging unit 11.

[0054] As described above, the X-ray imaging apparatus 4 comprises a transport unit 2 having a belt 7a, an X-ray imaging unit 11 provided above the transport unit 2, and shielding units 12 provided at the entrances and exits 11b and 11c of the X-ray imaging unit 11. The belt 7a functions as a surface on which the poultry thigh meat is placed. In this way, since the poultry thigh meat is placed on the belt 7a, the posture of the poultry thigh meat during transport can be stabilized compared to the conventional method of suspending the poultry thigh meat from a shackle. Furthermore, since the poultry thigh meat is simply placed on the belt 7a, there is no need to lift the poultry thigh meat as in the conventional method, thus reducing the workload.

[0055] The shielding unit 12 comprises a rotating shaft 16, a plurality of blades 17, and a drive unit 15 that 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 can be changed according to the position of the blades 17, and the gap between the belt 7a and the tip 19a of the blades 17 can always be kept constant. As a result, the shielding unit 12 can reliably shield X-rays leaking from the X-ray imaging device 4 to the outside, so even when a belt conveyor 7 is used for conveying poultry thigh meat, X-ray irradiation of the poultry thigh meat is possible.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] The present invention is not limited to the embodiments described above, and includes various modifications to the embodiments and their respective modifications without departing from the spirit of the invention. For example, in the embodiments described above, the X-ray imaging device 4 was described in the case where it is used in a 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.

[0062] 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.

[0063] In the above embodiment, the case where four blades 17 are provided was described. However, the number of blades 17 is not limited to this, and any number of blades 17 that can constantly shield X-rays from the X-ray imaging unit 11 is acceptable. The vertical actuator 22 should be driven according to the number of blades 17.

[0064] 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...Blade 19b...Chamfering unit 22...Vertical actuator 31...Linear motion mechanism 48...Electric motor (motor)

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, wherein the shielding unit is rotatably supported and has a rotation axis whose axis of rotation is in a direction intersecting the transport direction of the transport unit and the normal direction of the mounting surface; a plurality of vanes extending radially outward from the outer surface of the rotation axis; and a drive unit that rotates the rotation axis and moves the rotation axis up and down to move it closer to and further away from the transport unit according to the rotation position of the vanes.

2. The X-ray imaging apparatus according to claim 1, wherein the drive unit rotates and moves the rotating shaft up and down in synchronization with the transport unit.

3. The drive unit distances the rotating shaft from the transport unit as far as possible when the extension direction of the blades is aligned with the normal direction of the mounting surface described above, according to claim 1 or claim 2.

4. The X-ray imaging apparatus according to claim 1 or claim 2, wherein the number of blades is four, and the drive unit brings the rotation axis closest to the transport unit when the extension direction of the blades is aligned with a direction 45° to the normal direction of the mounting surface described above.

5. The X-ray imaging apparatus according to claim 1 or claim 2, wherein a chamfered portion is formed on the tip of the blade opposite to the rotation axis, on the upstream side in the rotation direction of the rotation axis.

6. The X-ray imaging apparatus according to claim 1 or claim 2, wherein the drive unit comprises a motor and a linear motion mechanism that converts the rotational motion of the motor into linear motion and transmits it to the rotating shaft.

Images