Radiation shielding device for security check CT (Computed Tomography)

Abstract

The invention relates to the technical field of radiation shielding, and discloses a radiation shielding device for security check CT, which comprises a rotating body with an inner hole in the center, a rotating support and a detector which are distributed up and down are mounted on the end face of one side of the rotating body, a shielding cylinder is mounted in the inner hole of the rotating body, and the shielding cylinder is in assembly connection with the rotating support and the detector. The two ends of the shielding cylinder are used for being in butt joint with an external channel, the ray source assembly is installed at the upper end of the rotating support, rays are emitted into the shielding cylinder through the ray source assembly, and ray signals are received by the detector. The first splayed opening is formed by the extension parts on the two sides of the shielding cylinder, and the fan-shaped rays are folded to the long arc-shaped opening and are received by the detector by utilizing the first splayed opening, so that the absorptivity of leaked rays is improved, the ray space is effectively wrapped, the rays are not leaked, the manufacturing and the assembly are convenient, the required shielding material is less, and the cost is low. And the equipment cost and the equipment weight can be obviously reduced.

Description

Technical Field

[0001] The invention relates to the technical field of radiation shielding, and in particular to a radiation shielding device for security inspection CT. Background Art

[0002] In today's society, with the continuous development of security inspection technology, security inspection CT equipment is widely used in public places such as airports, customs, and stations to conduct security inspections on luggage, cargo, etc. to ensure public safety.

[0003] However, during the operation of security CT equipment, radiation safety issues cannot be ignored. In addition to ensuring that the equipment can accurately collect CT data and achieve efficient security inspection functions, protecting people outside the equipment from radiation hazards has become a key issue that needs to be urgently resolved in the security CT field.

[0004] Currently, there are two main solutions for radiation shielding of security inspection CT equipment, namely, setting shielding materials on the equipment casing and setting shielding materials in the entire X-ray optical path space from the emission of the rays to the reception by the detector. However, both solutions have obvious limitations.

[0005] Although shielding materials can block radiation leakage to a certain extent, more shielding materials are required on the equipment shell. For example, in order to achieve effective shielding effect, the equipment shell often needs to be covered with shielding materials such as lead over a large area and in thick specifications. This not only greatly increases the equipment cost, making the cost of a single device increase by tens of thousands of yuan or even higher, but also significantly increases the weight of the equipment. During the installation, commissioning and daily maintenance of heavy equipment, professional lifting equipment and a large amount of manpower are required, which makes the operation difficult and the equipment inconvenient to move. It also places high demands on the bearing capacity of the installation site. In addition, the increase in equipment weight will affect its operating stability and increase energy consumption. In the long run, the operating cost will rise significantly. While setting shielding materials in the optical path space can theoretically reduce the usage amount of shielding materials to a certain extent and more effectively absorb the rays leaking outside the device, it faces many challenges in practical applications. On the one hand, how to accurately approach the optical path space to ensure effective absorption of rays while reducing the usage amount of shielding materials is a complex technical problem. The ray propagation path of the security inspection CT device is affected by various factors, such as the shape, density, and material of the object being detected. These factors make the scattering situation of rays in the optical path space extremely complex. Taking various goods inspected at customs as an example, the diversity of goods makes the scattering angle and intensity of rays changeable. It is difficult for the existing shielding material layout to completely cover all possible ray leakage paths. Even if the thickness of the shielding material is increased by focusing on shielding some key parts, it is difficult to ensure effective blocking of ray leakage in various complex situations. On the other hand, while ensuring effective enclosure of the ray space, ensuring no ray leakage at the joints with other components is another major problem. The internal structure of the security inspection CT device is complex, and each component will have small displacements due to factors such as vibration and temperature changes during operation. This makes it easy for gaps to appear at the joints between the shielding materials and other components. For example, at the connection between the rotating component and the shielding structure of the device, due to long-term relative movement, the joints of the shielding materials are extremely prone to loosening, resulting in ray leakage. Once ray leakage occurs, it will not only pose a potential threat to the physical health of device operators and surrounding personnel, but may also trigger public concerns about the safety of security inspection work and affect the normal development of security inspection work.

[0006] In addition, from the perspective of manufacturing and assembly, the scheme of setting shielding materials in the optical path space has extremely high requirements for manufacturing processes and assembly accuracy. During the manufacturing process, the shape and size of the shielding materials need to be precisely processed to enable them to closely fit the optical path space, and precise docking between each shielding component needs to be ensured during assembly. However, in the process of mass production, it is difficult to ensure that each shielding component can meet such high accuracy requirements, which leads to uneven product quality. Moreover, the complex manufacturing and assembly processes require a large number of skilled technical workers to participate, consuming a large amount of time and energy, increasing the production cost. At the same time, due to the great difficulty in assembly, once improper assembly occurs, the shielding effect will be greatly reduced, seriously affecting the radiation protection performance of the device.

[0007] In summary, there are many problems with the existing security inspection CT radiation shielding solutions, which cannot meet the growing security inspection needs and strict radiation safety standards. Therefore, it is extremely urgent to develop a radiation shielding device that can effectively enclose the ray space, reduce ray leakage, is easy to manufacture and assemble, and can reduce the cost and weight of the device. Summary of the Invention

[0008] To solve the technical problems existing in the background art, the present invention proposes a radiation shielding device for security inspection CT.

[0009] A radiation shielding device for security inspection CT proposed by the present invention includes a rotating body with a central inner hole. A rotating bracket and a detector are installed on one end face of the rotating body in an up-and-down distribution. A shielding cylinder is installed in the inner hole of the rotating body. The shielding cylinder is assembled and connected with the rotating bracket and the detector, and both ends of the shielding cylinder are used to dock with external channels. A ray source assembly is installed at the upper end of the rotating bracket. Rays are emitted into the shielding cylinder by the ray source assembly, and the detector receives the ray signals. A short arc-shaped opening and a long arc-shaped opening for the rays to enter and exit are respectively provided on the upper surface and the lower surface of the shielding cylinder. The upper surface of the shielding cylinder has a flared opening that docks with the rotating bracket. The top opening of the flared opening is smaller than the bottom opening, and the top opening of the flared opening has a return portion that docks with the ray source assembly. The flared opening receives the fan-shaped rays emitted by the ray source assembly and prevents the rays from leaking outwards. Both sides of the shielding cylinder have extending portions extending outwards. The two extending portions are symmetrically arranged on both side edges of the long arc-shaped opening to form a first inverted V-shaped opening. Axially, the first inverted V-shaped opening is opposite to the short arc-shaped opening, and the width of the first inverted V-shaped opening is greater than the width of the short arc-shaped opening. The fan-shaped rays emitted from the flared opening are converged to the long arc-shaped opening by the first inverted V-shaped opening and received by the detector. The rotating body is the core load-bearing component of the entire device, providing an installation basis for other components. The rotating bracket and the detector are installed on one end face of the rotating body in an up-and-down distribution, respectively used to support the ray source assembly and receive ray signals. The shielding cylinder is installed in the inner hole of the rotating body, and its two ends dock with external channels. It is the key part of radiation shielding. The short arc-shaped opening and the long arc-shaped opening are respectively the channels for the rays to enter and exit. Reasonable design of the opening shape and position can ensure the effective transmission of rays and reduce the risk of leakage. The flared opening is docked with the ray source assembly. Its special shape (small top opening and large bottom opening) and the design of the return portion enable the effective change of the ray propagation direction when receiving fan-shaped rays, confine the rays within the shielding cylinder, and prevent the rays from leaking outwards. The extending portions on both sides of the shielding cylinder form a first inverted V-shaped opening. Utilizing the characteristics that its width is greater than that of the short arc-shaped opening and it is axially opposite to the short arc-shaped opening, the fan-shaped rays that may be emitted from the flared opening are converged to the long arc-shaped opening, enabling the detector to receive the rays more effectively, improving the utilization rate of the rays, and further preventing the rays from leaking into the external environment to ensure the safety of personnel.

[0010] As a further optimized solution of the present invention, the rotating bracket includes a bracket body. The upper end of the bracket body has a second eight-shaped opening adapted to the bell mouth, and the opening of the second eight-shaped opening extends upward to form a bracket loop protrusion. The upper end surface of the rotating bracket has a bracket loop groove located outside the bracket loop protrusion to form a U-shaped interface for docking with the radiation source assembly; The bracket body is the main structure of the rotating bracket, providing installation and support for other components. The second eight-shaped opening is adapted to the bell mouth on the shielding cylinder, and the two fit tightly, which helps with accurate positioning and connection, ensuring the accuracy of the radiation transmission path. The upward-extending bracket loop protrusion and the bracket loop groove located outside it together form a U-shaped interface. When docking with the radiation source assembly, it can not only achieve stable connection, but also further optimize the radiation transmission space, reduce the leakage risk of radiation at the interface, ensure that the radiation emitted by the radiation source assembly can accurately enter the shielding cylinder, and improve the overall performance of the radiation shielding device.

[0011] As a further optimized solution of the present invention, the shielding cylinder includes an upper shielding component, a lower shielding component, a front shielding component, a rear shielding component, and a seam covering ring. The upper shielding component and the lower shielding component are respectively installed on the inner walls of the rotating bracket and the detector, and the upper shielding component and the lower shielding component are assembled with each other. The front shielding component is installed on the front end faces of the rotating bracket and the detector, and the docking seams of the upper shielding component, the lower shielding component, and the front shielding component are covered by the seam covering ring. The rear shielding component is installed in the inner hole of the rotating body and is lap-mounted with the rear edges of the upper shielding component and the lower shielding component; The upper shielding component and the lower shielding component are respectively installed on the inner walls of the rotating bracket and the detector to jointly shield the radiation. The two are assembled with each other to form a first radiation channel, effectively blocking the leakage of radiation from the gap between the rotating bracket and the detector. The front shielding component is installed on the front end face to prevent radiation from leaking from the front end of the device; the rear shielding component is installed at the rear end to block the leakage of radiation from parts such as the belt pulley, bearing, and slip ring at the rear end. The seam covering ring covers the docking seams of each component to further prevent radiation from leaking out through the gaps. These components work together to comprehensively wrap the radiation transmission space, greatly improving the radiation shielding effect.

[0012] As a further optimized solution of the present invention, the upper shielding component includes a semicircular matrix shielding layer, a bell-mouth-shaped opening shielding layer, and a loop-shaped top shielding layer. The matrix shielding layer is covered and installed on the inner wall of the rotating bracket. A short arc-shaped opening is provided at the top of the matrix shielding layer. The opening shielding layer is installed on the upper surface of the matrix shielding layer and covers the outside of the short arc-shaped opening. The top shielding layer is installed at the upper end opening of the opening shielding layer; The matrix shielding layer covers the inner wall of the rotating bracket and has an absorption effect on the scattered rays with low energy after multiple scatterings. Its semi-circular arc design fits the inner wall of the rotating bracket to ensure the integrity of shielding. The short arc opening is opened at the top of the matrix shielding layer and is the key channel for the rays to enter. The opening shielding layer is in a flared shape and covers the outside of the short arc opening. Its relatively large thickness (5 - 10 mm) can absorb the strong rays directly emitted from the ray source, further protecting the external environment from strong radiation. The top shielding layer is in a loop structure and is installed at the upper opening of the opening shielding layer, docking with the loop groove at the lower part of the ray source assembly, and can effectively absorb the low-energy scattered rays after multiple refractions. The three-layer structure works together to improve the shielding ability of the upper shielding assembly for rays with different energies.

[0013] As a further optimized solution of the present invention, a first reinforcing layer located around the short arc opening is installed on the lower surface of the matrix shielding layer. Outer convex extension parts are provided on both inner side surfaces of the two ends of the matrix shielding layer, and the two extension parts are symmetrical to form a third eight-character opening. A second reinforcing layer is installed on the inner wall of the third eight-character opening; Near the short arc opening, the ray energy is relatively high, and it is difficult to completely absorb only by the matrix shielding layer. The first reinforcing layer is installed on the lower surface of the matrix shielding layer around the short arc opening, increasing the shielding ability of this area and covering the joint between the opening shielding layer and the matrix shielding layer to prevent the rays from leaking from the joint. X-ray direct rays pass through the third eight-character opening at both inner side surfaces of the two ends of the matrix shielding layer, and the intensity of the scattered rays is relatively high. The second reinforcing layer is installed on the inner wall of the third eight-character opening and can effectively absorb the direct rays and scattered rays here, further improving the shielding effect and ensuring the reliability of the entire shielding device.

[0014] As a further optimized solution of the present invention, the detector includes a detector body installed at the lower end of the inner hole of the rotating body and in a semi-circular ring shape. The detector body has a detector opening. Through the detector opening, the inner arc surface of the detector body is divided into a detector first inner arc surface and a detector second inner arc surface. The top edges at both ends of the detector body sink to form a detector step part. The lower shielding component is covered and installed on the outer surfaces of the detector first inner arc surface, the detector second inner arc surface, and the detector step part, and the shape of the lower shielding component is consistent with the inner arc surface and the top of the detector body; The detector body is in a semi-circular ring shape and is installed at the lower end of the inner hole of the rotating body. Its detector opening is used to distinguish the detector first inner arc surface and the detector second inner arc surface, providing different detection areas for receiving rays. The design of the detector step part facilitates docking with the lower shielding component. The lower shielding component covers the relevant surfaces of the detector body and has a matching shape, enabling close fitting, effectively shielding the rays inside the detector to prevent their leakage, and at the same time ensuring the accuracy of the detector receiving rays and avoiding interference from external rays to the normal operation of the detector.

[0015] As a further optimized solution of the present invention, the lower shielding component is provided with an arc-shaped opening consistent with the detector opening. The arc-shaped opening divides the lower shielding component into a first inner arc surface of the lower shield and a second inner arc surface of the lower shield. The first inner arc surface of the lower shield and the second inner arc surface of the lower shield correspond to the first inner arc surface of the detector and the second inner arc surface of the detector respectively. Both ends of the lower shielding component have lower shielding step portions, and the lower shielding step portions correspond to and are snap-fitted with the detector step portions; The arc-shaped opening on the lower shielding component is consistent with the detector opening, ensuring that the rays can smoothly enter the detector. The first inner arc surface of the lower shield and the second inner arc surface of the lower shield respectively correspond to the two inner arc surfaces of the detector, further optimizing the shielding and guiding of the rays, ensuring the accuracy of the ray signals received by the detector. The lower shielding step portion is snap-fitted with the detector step portion, enhancing the stability of the connection between the two. On the one hand, the lower shielding step portion can absorb the rays inside the detector, and on the other hand, it is docked with the U-shaped groove at the bottom of the matrix shielding layer to form a first ray channel, enabling the rays to be refracted and absorbed multiple times in the channel, improving the absorption efficiency of the scattered rays and reducing ray leakage.

[0016] As a further optimized solution of the present invention, the front shielding component includes a support plate installed on the rotating bracket and the front end face of the detector. A support ring coaxially centered and having the same diameter as the support plate is installed on the support plate, and a protective ring is installed on the inner wall of the support ring; The support plate and the support ring provide installation support for the protective ring. They are made of materials with good strength and processability, such as steel, aluminum, engineering plastics, etc., ensuring the structural stability of the front shielding component. The protective ring is made of a shielding material and is installed on the inner wall of the support ring to directly shield the rays. This structural design effectively blocks the leakage of rays from the front end faces of the rotating bracket and the detector while ensuring the structural strength, protecting the front-end equipment and personnel from radiation hazards.

[0017] As a further optimized solution of the present invention, the rear shielding component includes an upper semi-circle body and a lower semi-circle body with equal arcs; the upper semi-circle body includes an upper support ring and an upper protective ring covering and installed on the inner wall of the upper support ring. The front end of the upper support ring extends outside the upper protective ring to form an upper skirt edge for docking with the upper shielding component; the lower semi-circle body includes a lower support ring and a lower protective ring covering and installed on the inner wall of the lower support ring. The front end of the lower support ring extends outside the lower protective ring to form a lower skirt edge for docking with the lower shielding component; both sides of the upper protective ring extend outside both ends of the upper support ring to form a circumferential skirt edge. When the upper semi-circle body and the lower semi-circle body are spliced, the circumferential skirt edge overlaps on the inner surface of the lower protective ring to prevent ray leakage at the docking location; The rear shielding component adopts an upper and lower semi-circular design, which is convenient for manufacturing and installation, can better ensure the coaxiality and roundness with other components, and reduce the risk of ray leakage. The upper support ring and the lower support ring provide a support structure for the upper protective ring and the lower protective ring. They are made of materials with good strength and machinability. The upper protective ring and the lower protective ring adopt shielding materials to directly shield the rays. The upper skirt and the lower skirt are respectively docked with the upper shielding component and the lower shielding component. The circumferential skirt overlaps on the inner surface of the lower protective ring when the upper and lower semi-circular bodies are spliced. The multi-layer skirt structure effectively avoids the leakage of rays at the docking part, and comprehensively protects the safety of the rear-end equipment and personnel.

[0018] As a further optimized solution of the present invention, multiple columns of mounting holes distributed circumferentially are provided on the inner walls of the upper semi-circular body and the lower semi-circular body. The upper semi-circular body and the lower semi-circular body are fixed to the inner wall of the inner hole of the rotating body by screws, and a shielding plate covering the opening of the mounting hole is installed on the inner walls of the upper semi-circular body and the lower semi-circular body; The mounting holes are designed as long strip holes distributed in multiple columns circumferentially, which is convenient for the installation of the rear shielding component and the rotating body. Even if there is a certain circumferential error in the hole positions, the installation can still be completed, reducing the manufacturing precision requirements. The screws pass through the mounting holes to fix the rear shielding component to the inner wall of the inner hole of the rotating body. The shielding plate is installed at the opening of the mounting hole and is made of shielding material to prevent the leakage of rays from the mounting holes, further improving the safety and reliability of the radiation shielding device.

[0019] The radiation shielding device for security inspection CT proposed by the present invention has the following beneficial effects: (1) Through the unique shielding cylinder design of the present device, the flared mouth is docked with the ray source component, effectively receiving the fan-shaped rays and preventing their leakage. The first eight-shaped openings on both sides of the shielding cylinder converge the possibly emitted fan-shaped rays to the long arc-shaped opening for the detector to receive, greatly improving the absorption rate of the leaked rays, ensuring that the rays are effectively wrapped inside the device and hardly leaking to the external environment, greatly reducing the radiation hazard to equipment operators and surrounding personnel, protecting the physical health of personnel, eliminating the public's concern about the safety of security inspection work, and providing a strong guarantee for the smooth progress of security inspection work; (2) The present device requires less shielding material. By optimizing the shielding cylinder structure and the ray transmission path, on the premise of ensuring high-efficiency shielding effect, the usage amount of shielding material is reduced. This not only reduces the manufacturing cost of the equipment, but also reduces the weight of the equipment, making it unnecessary to rely on large lifting equipment and a large amount of manpower during the installation, debugging and daily maintenance of the equipment, reducing the operation difficulty, reducing the requirements for the bearing capacity of the installation site, and at the same time improving the stability of the equipment operation, reducing the energy consumption and operation cost; (3) The structure of this device is reasonably designed. Each component, such as the upper shielding component, lower shielding component, front shielding component, and rear shielding component of the shielding cylinder, as well as the rotating bracket, detector, etc., adopts a structure that is convenient for manufacturing and assembly, making it easier to control the product quality, improving production efficiency, and reducing production costs; (4) Through the multi-layer shielding structure and special opening design, this device can adapt to complex ray scattering situations. For example, the upper shielding component of the shielding cylinder consists of a matrix shielding layer, an opening shielding layer, and a top shielding layer, which respectively absorb rays of different energies; the second strengthening layers at both ends of the matrix shielding layer and the lower shielding step of the lower shielding component effectively absorb direct rays and scattered rays in specific areas. Each component cooperates closely to comprehensively wrap the ray transmission space, ensuring effective blocking of ray leakage in various complex situations, and improving the reliability and stability of the shielding device; (5) The ray transmission path of this device has been optimized. The reasonable setting of the short arc opening and long arc opening, as well as the synergistic effect of structures such as the flared opening and the first eight-shaped opening, ensure that rays can be accurately and efficiently transmitted to the detector. At the same time, the close cooperation between the detector and the shielding component reduces the interference of external rays on the detector, ensuring the accuracy of the detector receiving ray signals, thereby improving the detection accuracy of the security inspection CT equipment, helping to more accurately detect items such as luggage and goods, and enhancing the quality and efficiency of the security inspection work.

[0020] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a three-dimensional structure schematic diagram of the present invention; Figure 2 is a three-dimensional structure schematic diagram of the shielding cylinder of the present invention; Figure 3 is a side cross-sectional structure schematic diagram of the shielding cylinder of the present invention; Figure 4 is a disassembled structure schematic diagram of the shielding cylinder of the present invention; Figure 5 is an assembly structure schematic diagram of the rotating bracket and the upper shielding component of the present invention; Figure 6 is a bottom view structure schematic diagram of the rotating bracket of the present invention; Figure 7 is a front cross-sectional structure schematic diagram of the rotating bracket of the present invention; Figure 8 is a three-dimensional structure schematic diagram of the upper shielding component of the present invention; Figure 9 is a bottom view structure schematic diagram of the upper shielding component of the present invention; Figure 10 Structural schematic diagram of the second reinforcement layer of the present invention; Figure 11 Side cross-sectional structural schematic diagram of the upper shielding component of the present invention; Figure 12 Front cross-sectional structural schematic diagram of the upper shielding component of the present invention; Figure 13 Split structural schematic diagram of the detector and the lower shielding component of the present invention; Figure 14 Docking assembly schematic diagram of the upper shielding component and the lower shielding component of the present invention; Figure 15 Structural schematic diagram of the front shielding component of the present invention; Figure 16 Assembly schematic diagram of the upper shielding component, the front shielding component and the gap shielding ring of the present invention; Figure 17 Split structural schematic diagram of the rear shielding component of the present invention; Figure 18 Assembly structural schematic diagram of the rear shielding component and the rotating body of the present invention; Figure 19 Side cross-sectional structural schematic diagram of the shielding cylinder of the present invention; Figure 20 Schematic diagram of an application example of the present invention; Figure 21 Inverted structural schematic diagram of the ray source component of the present invention; Figure 22 Docking structural schematic diagram of the shielding cylinder and the ray source of the present invention; Figure 23 Structural schematic diagram of the counterweight component of the present invention; Figure 24 For the present invention Figure 11 Enlarged schematic diagram at position A in; Figure 25 For the present invention Figure 12 Enlarged schematic diagram at position B in; Figure 26 For the present invention Figure 12 Enlarged schematic diagram at position C in; Figure 27 For the present invention Figure 14 Enlarged schematic diagram at position D in; Figure 28 For the present invention Figure 16 Enlarged schematic diagram at position E in; Figure 29 For the present invention Figure 17 Enlarged schematic diagram at position F in; Figure 30 For the present invention Figure 19 Enlarged schematic diagram at position G in; Figure 31 For the present invention Figure 19 The enlarged schematic view of the position H in the present invention; Figure 32 For the present invention Figure 19 The enlarged schematic view of the position I in the present invention; Figure 33 For the present invention Figure 22 The enlarged schematic view of the position J in the present invention.

[0022] Description of the drawings: 1. Rotating body; 2. Rotating bracket; 201. Bracket body; 202. Side convex platform; 203. Side flange; 204. Groove; 205. C-shaped groove; 206. Second eight-shaped opening; 207. Bracket return protrusion; 208. Bracket return groove; 3. Detector; 301. Detector body; 302. First inner arc surface of the detector; 303. Second inner arc surface of the detector; 304. Detector step part; 4. Shielding cylinder; 41. Upper shielding component; 411. Matrix shielding layer; 412. Opening shielding layer; 413. Top shielding layer; 414. First strengthening layer; 415. Second strengthening layer; 4151. Bottom plate; 4152. Arc-shaped flanging; 4153. Inclined surface flanging; 42. Lower shielding component; 421. First inner arc surface of the lower shield; 422. Second inner arc surface of the lower shield; 423. Lower shield step part; 43. Front shielding component; 431. Support plate; 432. Support ring; 433. Protection ring; 44. Rear shielding component; 441. Upper support ring; 442. Upper protection ring; 443. Upper skirt; 444. Circumferential skirt; 445. Lower support ring; 446. Lower protection ring; 447. Lower skirt; 45. Gap shielding ring; 5. Radiation source component; 6. First counterweight component; 7. Second counterweight component; 8. Third counterweight component; 9. Short arc opening; 10. Long arc opening; 14. First ray channel; 15. Counterweight plate; 16. Mounting hole; 17. Screw; 18. Shutter; 19. CT fixing frame; 20. First over-packing channel; 21. Second over-packing channel; 22. Baffle; 23. Retaining ring; 24. Beam outlet; 25. Radiation source return protrusion; 26. Radiation source return groove; 27. Second ray channel; 28. Counterweight seat; 29. Screw rod. Detailed implementation manners

[0023] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar symbols represent the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation to the present invention.

[0024] As Figures 1 - 3As shown in the figure, a radiation shielding device for security inspection CT includes a rotating body 1 with an inner hole at the center. On one end face of the rotating body 1, a rotating bracket 2 and a detector 3 are installed vertically. A shielding cylinder 4 is installed in the inner hole of the rotating body 1. The shielding cylinder 4 is assembled and connected with the rotating bracket 2 and the detector 3, and both ends of the shielding cylinder 4 are used to dock with external channels. A ray source assembly 5 is installed at the upper end of the rotating bracket 2. Rays are emitted into the shielding cylinder 4 through the ray source assembly 5, and the ray signals are received by the detector 3. On the upper surface and the lower surface of the shielding cylinder 4, short arc-shaped openings 9 and long arc-shaped openings 10 for the rays to enter and exit are respectively provided. The upper surface of the shielding cylinder 4 has a flared opening that docks with the rotating bracket 2. The flared opening is composed of two arc-shaped flat plates and two bent plates, forming a flared structure, that is, the top opening is smaller than the bottom opening. The arc-shaped flat plates are perpendicular to the axis, and the bent plates are parallel to the axis. The top opening of the flared opening is smaller than the bottom opening, and the top opening of the flared opening has a return-shaped part that docks with the ray source assembly 5. The fan-shaped rays emitted by the ray source assembly 5 are received through the flared opening and prevent the rays from leaking outwards. The return-shaped part is a rectangular ring-shaped plane formed by the upper opening edge of the top flared opening extending along the plane direction. The outer edge of the plane is turned downwards to form a ring-shaped structure with an L-shaped cross-section, which is used to dock with the ray source assembly 5 and leaves a certain gap to form a ray channel with a U-shaped cross-section, which not only ensures that the rays at the docking part do not leak, but also can realize the displacement adjustment of the ray source. Both sides of the shielding cylinder 4 have extended parts extending outwards. The two extended parts are symmetrically arranged on both side edges of the long arc-shaped opening 10 to form a first eight-shaped opening. The extended part is composed of three flat plates, a rectangular flat plate and two approximately triangular flat plates. The two side edges of the long arc-shaped opening 10 are connected to the edge of the rectangular flat plate, and the two approximately triangular flat plates on both sides are connected to the arc-shaped edge of the long arc-shaped opening. Axially, the first eight-shaped opening is opposite to the short arc-shaped opening 9, and the width of the first eight-shaped opening is greater than the width of the short arc-shaped opening. The fan-shaped rays emitted from the flared opening are converged to the long arc-shaped opening 10 through the first eight-shaped opening and received by the detector 3. A first counterweight assembly 6, a second counterweight assembly 7, and a third counterweight assembly 8 are respectively installed on one side of the rotating bracket 2, the bottom of the circumferential surface of the detector 3, and the bottom of the end face, so as to balance the masses of the rotating components on the CT and the shielding cylinder 4 and ensure the dynamic balance accuracy of the CT rotation. As Figure 23 shown, the first counterweight assembly 6, the second counterweight assembly 7, and the third counterweight assembly 8 all include a counterweight plate 15, a counterweight seat 28, and a screw 29. The number of screws 29 is two and they are symmetrically installed on the counterweight seat 28. Two long strip holes are symmetrically distributed on the counterweight plate 15. The counterweight plate 15 is sleeved on the two screws 29 through the long strip holes and fixed by nuts. The counterweight plates 15 at the bottoms of the second counterweight assembly 7 and the third counterweight assembly 8 are rectangular, and the long holes formed thereon can reduce the manufacturing and welding precision of the screw rods, facilitating assembly. The counterweight plate 15 on the first counterweight assembly 6 is convex, with long holes formed thereon, and the long holes are longer than those of the bottom counterweight pieces, facilitating the axial movement of the counterweight plate 15 to adjust the center of gravity position in the axial direction of the counterweight plate 15 to achieve dynamic balance. When a large-distance adjustment of the center of gravity is required, due to the compact layout of the CT, simply moving the axial position of the counterweight piece will cause interference between the counterweight piece and the rotor bracket or outer components. However, the convex design can make the center of gravity of the counterweight piece deviate to one side. When a large-range movement of the center of gravity position is needed, the convex counterweight piece can be rotated 180°, so that the center of gravity can be adjusted over a large distance, and while leaving as much space as possible for other components, the dynamic balance accuracy required by the system can be achieved; The shielding cylinder 4 includes an upper shielding assembly 41, a lower shielding assembly 42, a front shielding assembly 43, a rear shielding assembly 44, and a slit shielding ring 45. The upper shielding assembly 41 and the lower shielding assembly 42 are respectively installed on the inner walls of the rotating bracket 2 and the detector 3, and the upper shielding assembly 41 and the lower shielding assembly 42 are assembled with each other. The front shielding assembly 43 is installed on the front end faces of the rotating bracket 2 and the detector 3, and the docking seams of the upper shielding assembly 41, the lower shielding assembly 42, and the front shielding assembly 43 are covered by the slit shielding ring 45. The rear shielding assembly 44 is installed in the inner hole of the rotating body 1 and is lap-mounted with the rear edges of the upper shielding assembly 41 and the lower shielding assembly 42; The inner wall of the rotating bracket 2 provides an attachment surface for the upper shielding assembly 41, and the inner arc surface of the detector 3 provides an attachment surface for the lower shielding assembly 42. Both the upper shielding assembly 41 and the lower shielding assembly 42 are made of materials that can shield X-rays (hereinafter referred to as shielding materials), preferably materials with a high atomic number and high density, such as lead; The front shielding assembly 43 and the rear shielding assembly 44 are used to dock with external channels and prevent the leakage of rays at parts such as pulleys, bearings, and slip rings at the rear end of the CT.

[0025] Specifically, as Figures 5 - 7 shown, the rotating bracket 2 includes a bracket body 201. The upper end of the bracket body 201 has a second eight-shaped opening 206 adapted to the bell mouth, and the opening of the second eight-shaped opening 206 extends upward to form a bracket loop-shaped protrusion 207. The upper end surface of the rotating bracket 2 has a bracket loop-shaped groove 208 located outside the bracket loop-shaped protrusion 207 to form a U-shaped interface for docking with the ray source assembly 5; As Figure 5 shown, both sides of the bottom of the bracket body 201 are flat and extend horizontally to form side flanges 203. A U-shaped groove 205 is formed on the bottom surface of the side flanges 203, and the openings of the U-shaped grooves 205 on both sides face the inside of the bracket body 201; As Figure 6 and Figure 7As shown, on both sides of the inner wall of the bracket body 201, there are a pair of grooves 204. The grooves 204 are connected to the opening edges of the U-shaped groove 205. The axial central plane of the groove 204 is aligned with the axial central plane of the second eight-shaped opening 206. The groove 204 is used to avoid the ray beam. Since the ray optical path is a conical beam, the top opening and the side wall opening are eight-shaped, ensuring that the beam passing through this place is effectively received by the detector; As Figure 5 shown, on the outer surface side wall of the bracket body 201, there is a side boss 202. The top surface of the side boss 202 is a plane and is parallel to the axis. The normal plane of the side boss 202 passes through the rotation center, and the angle between the normal plane and the axial central plane of the CT is α, and the value of α is 60 - 70°, which is used to assemble the first counterweight assembly 6.

[0026] Specifically, as Figures 8 - 12 shown, the upper shielding component 41 includes a semicircular arc-shaped matrix shielding layer 411, a flared opening shielding layer 412, and a loop-shaped top shielding layer 413. The matrix shielding layer 411 is covered and installed on the inner wall of the rotating bracket 2. A short arc-shaped opening 9 is opened at the top of the matrix shielding layer 411. The opening shielding layer 412 is installed on the upper surface of the matrix shielding layer 411 and covers the outside of the short arc-shaped opening 9. The top shielding layer 413 is installed at the upper end opening of the opening shielding layer 412; The matrix shielding layer 411 covers the inner wall of the bracket body 201, the groove 204, the U-shaped groove 205, and the lower surface of the side flange 203. And the shape of the matrix shielding layer 411 is consistent with the inner surface of the bracket body 201. The thickness of the matrix shielding layer 411 is 3 - 5 mm, which is used to absorb scattered rays with lower energy; The opening shielding layer 412 covers the inner wall of the second eight-shaped opening 206, enclosing a flared structure. The upper part is a plane opening, and the lower part is an arc-shaped opening. The arc-shaped opening is connected to the short arc-shaped opening 9 on the upper surface of the matrix shielding layer 411. The thickness of the opening shielding layer 412 is 5 - 10 mm, which is used to absorb strong rays; The top shielding layer 413 is a loop-shaped structure and its cross-section is L-shaped. The thickness of the top shielding layer 413 is 1 - 3 mm. The top shielding layer 413 is buckled on the top surface and the outer side wall of the bracket loop-shaped protrusion 207. The top shielding layer 413 is docked with the loop-shaped groove at the lower part of the ray source assembly 5, forming a channel with a U-shaped cross-section, which is used to absorb low-energy scattered rays that have undergone multiple refractions; Furthermore, as Figure 9As shown, a first reinforcing layer 414 is mounted on the lower surface of the matrix shielding layer 411 and is located outside the short arc-shaped opening 9. The thickness of the first reinforcing layer 414 is 2-4 mm. The first reinforcing layer 414 is an arc-shaped rectangular ring structure, and flanges are provided at both inner edges. It covers the joint between the opening shielding layer 412 and the matrix shielding layer 411. The outer arc curvature of the first reinforcing layer 414 is the same as the inner arc surface of the matrix shielding layer 411. The opening edge of the first reinforcing layer 414 is flush with the inner wall of the opening shielding layer 412 in the axial direction. The flanges on both sides of the first reinforcing layer 414 extend upward and are attached to the bottom of the inner walls of the two slanted sides of the opening shielding layer 412. The scattered ray energy near the top opening of the matrix shielding layer 411 is relatively high, and only using the matrix shielding layer 411 cannot effectively absorb the rays. Therefore, a first reinforcing layer 414 is added near the opening to increase the ray absorption capacity near the opening. In addition, the first reinforcing layer 414 can cover the joint between the opening shielding layer 412 and the matrix shielding layer 411 to prevent rays from leaking from the joint; Outwardly protruding extension parts are provided on the inner side surfaces at both ends of the matrix shielding layer 411, and the two extension parts are symmetrical to form a third slanted opening, and a second reinforcing layer 415 is mounted on the inner wall of the third slanted opening; As Figure 10 shown, the thickness of the second reinforcing layer 415 is 2-4 mm. The second reinforcing layer 415 is composed of a bottom plate 4151, an arc-shaped flange 4152, and an inclined flange 4153. The bottom plate 4151 covers the inner wall of the third slanted opening of the matrix shielding layer 411. There is an arc-shaped flange 4152 on one side of the bottom plate 4151, and there is an inverted U-shaped opening in the middle of the arc-shaped flange 4152. The arc-shaped flange 4152 is attached to the inner wall of the matrix shielding layer 411. There is an inclined flange 4153 at the edge of the notch of the bottom plate 4151, and the inclined flange 4153 is attached to the inclined surface of the inner wall of the third slanted opening. X-ray direct rays pass through the third slanted opening, and the scattered ray intensity at this place is relatively high. Therefore, second reinforcing layers 415 need to be installed on both sides of the matrix shielding layer 411 to absorb the direct rays and scattered rays at this place.

[0027] Specifically, as Figure 13As shown in the figure, the detector 3 includes a detector body 301 which is semicircular ring-shaped and installed at the lower end of the inner hole of the rotating body 1. The detector body 301 has a detector opening, and the detector opening is opposite to the third eight-shaped opening on the inner side of the matrix shielding layer 411. The inner arc surface of the detector body 301 is divided into a detector first inner arc surface 302 and a detector second inner arc surface 303 through the detector opening. The top edges at both ends of the detector body 301 sink to form a detector step portion 304. The ends of the detector first inner arc surface 302 and the detector second inner arc surface 303 are connected to the top of the detector body 301. U-shaped openings are formed on the top planes on both sides of the detector body 301. The lower shielding component 42 is covered and installed on the outer surfaces of the detector first inner arc surface 302, the detector second inner arc surface 303, and the detector step portion 304. The thickness of the lower shielding component 42 is 2-4 mm, and the shape of the lower shielding component 42 is consistent with the inner arc surface and the top of the detector body 301; The detector first inner arc surface 302, the detector second inner arc surface 303, and the inner arc surface of the bracket body 201 are coaxial and also coincide with the CT rotation axis; The front of the detector body 301 is provided with a plurality of positioning holes distributed along the circumference for installing the front shielding component 43; there are two positioning holes near the bottom for installing the second counterweight component 7; Further, a long arc-shaped opening 10 consistent with the detector opening is formed on the lower shielding component 42. The long arc-shaped opening 10 divides the lower shielding component 42 into a lower shielding first inner arc surface 421 and a lower shielding second inner arc surface 422. The lower shielding first inner arc surface 421 and the lower shielding second inner arc surface 422 correspond to the detector first inner arc surface 302 and the detector second inner arc surface 303 respectively. Both ends of the lower shielding component 42 have lower shielding step portions 423, and the lower shielding step portions 423 correspond to and are snap-fitted with the detector step portions 304; As Figure 14 shown, the lower shielding first inner arc surface 421 and the lower shielding second inner arc surface 422 are used to absorb the stronger scattered rays at the edge of the light beam. The lower shielding step portion 423 is used to dock with the U-shaped groove at the bottom of the matrix shielding layer 411 to form a first ray channel 14. The gap between the two second strengthening layers 415 and the adjacent lower shielding step portions 423 is 0.5-3 mm. The first ray channel 14 is L-shaped, which can make the rays refract and be absorbed multiple times. And the smaller the channel gap, the more times the scattered rays refract and the more rays are absorbed by the inner wall. And this docking surface is made of shielding material with a relatively soft texture and is not suitable as an assembly surface. Therefore, a certain gap must be provided to avoid interference of parts on this surface during assembly on other rigid surfaces. The gap here is relatively small, so the L-shaped ray channel can effectively absorb the scattered rays at this place; The lower shielding step portion 423 is used to absorb the internal rays of the detector 3. Axially, the third eight-shaped opening inside the matrix shielding layer 411 is opposite to the long arc-shaped opening 10 on the lower shielding assembly 42, and the width of the long arc-shaped opening 10 is not less than the width of the third eight-shaped opening, so as to pass the X-rays and then be received by the detection plate in the detector body 301, thereby forming CT image data.

[0028] Specifically, as Figure 15 shown, the front shielding assembly 43 includes a support plate 431 installed on the front end faces of the rotating bracket 2 and the detector 3 and having a central hole. A support ring 432 coaxially centered and having the same diameter as the support plate 431 is installed on the support plate 431. A protective ring 433 is installed on the inner wall of the support ring 432. Both the support plate 431 and the support ring 432 are made of materials with good strength and good machinability, such as steel, aluminum, engineering plastics, etc., while the protective ring 433 is made of a shielding material; There is a large circular hole in the center of the support plate 431, and there are multiple mounting holes at the edge. The mounting holes correspond one by one to the positioning holes on the front surface of the bracket body 201 and the front surface of the detector body 301, and are fastened with screws. The support ring 432 is circular and has the same diameter as the central circular hole of the support plate 431. The support plate 431 and the support ring 432 can be an integral structure or can be welded separately. The protective ring 433 covers the inner wall of the support ring 432, and the width of the protective ring 433 is equal to that of the support ring 432, and the thickness is 2 - 4 mm; As Figure 16 shown, a circular shielding ring 45 is provided at the docking part of the front shielding assembly 43 with the upper shielding assembly 41 and the lower shielding assembly 42 to cover the docking seams of the front shielding assembly 43 with the upper shielding assembly 41 and the lower shielding assembly 42, so as to prevent rays from leaking from the seams. The shielding ring 45 is made of a shielding material, with a width of 15 - 30 mm and a wall thickness of 1 - 3 mm. The shielding ring 45 can be a whole or can be assembled in multiple segments.

[0029] Specifically, as Figure 17 and Figure 18 shown, the rear shielding assembly 44 includes an upper semi-circle body and a lower semi-circle body with equal arcs; The upper semi-circle body includes an upper support ring 441 and an upper protective ring 442 covering and installed on the inner wall of the upper support ring 441. The front end of the upper support ring 441 extends to the outside of the upper protective ring 442 to form an upper skirt 443 for docking with the upper shielding assembly 41, so as to prevent rays from leaking at the docking part; The lower semi-circle body includes a lower support ring 445 and a lower protective ring 446 covering and installed on the inner wall of the lower support ring 445. The front end of the lower support ring 445 extends to the outside of the lower protective ring 446 to form a lower skirt 447 for docking with the lower shielding assembly 42, so as to prevent rays from leaking at the docking part; Both sides of the upper shielding ring 442 extend to the outside of both ends of the upper support ring 441 to form a circumferential skirt 444. When the upper semi-ring body and the lower semi-ring body are spliced, the circumferential skirt 444 overlaps on the inner surface of the lower shielding ring 446 to prevent ray leakage at the docking joint. Both the upper support ring 441 and the lower support ring 445 are made of materials with good strength and processability, such as steel, aluminum, engineering plastics, etc. The upper shielding ring 442 and the lower shielding ring 446 are made of shielding materials with a thickness of 2-4 mm. If the upper semi-ring body and the lower semi-ring body are made as a whole, due to the large axial width of the rear shielding assembly 44, it is difficult to ensure the cylindricity during the processing. After processing, it has a certain stiffness and poor cylindricity. After installation, it is impossible to ensure the coaxiality of the rear shielding assembly 44 with the upper shielding assembly 41 and the lower shielding assembly 42 well, so it is difficult to ensure the gap with the external channel, resulting in the risk of ray leakage. Therefore, in this solution, the whole ring body is divided into upper and lower parts, which is convenient for manufacturing. Since the upper and lower ring bodies have a certain elasticity, they can better fit on the inner arc surface of the central circular hole of the rotating body 1. Thus, after assembly, the roundness of the ring body at the docking joint of the rear shielding assembly 44 and the external channel is better, and the coaxiality with the upper shielding assembly 41 and the lower shielding assembly 42 is also better, and it can maintain the designed gap with the external channel, ensuring a certain rotational gap and avoiding ray leakage. Furthermore, as Figures 17 - 19 shown, multiple rows of circumferentially distributed mounting holes 16 are provided on the inner walls of the upper semi-ring body and the lower semi-ring body. The upper semi-ring body and the lower semi-ring body are fixed to the inner wall of the inner hole of the rotating body 1 by screws 17, and a cover plate 18 covering the openings of the mounting holes 16 is installed on the inner walls of the upper semi-ring body and the lower semi-ring body. The mounting holes 16 are in the shape of long slots, and the length direction of the holes is circumferential. The diameters of the mounting holes 16 on the upper shielding ring 442 and the lower shielding ring 446 are larger than those of the mounting holes 16 on the upper support ring 441 and the lower support ring 445 to avoid the heads of the screws 17 and facilitate the sinking of the heads of the screws 17 so that the heads of the screws 17 contact the upper support ring 441 and the lower support ring 445. Since the material of the shielding ring is soft and prone to low-temperature creep, if the screws are directly locked on the shielding ring, they are likely to loosen later. The rotating body 1 is any rotating part in the shielding system, which can be a large pulley, a bearing or other rotating parts, or can be assembled by multiple rotating parts. Its characteristic structure is: a large circular hole is provided in the center, the inner diameter of the large circular hole is the same as the outer diameter of the rear shielding assembly 44, and two rows or more rows of screw holes are distributed circumferentially. The positions of all the screw holes correspond to the positions of multiple mounting holes 16 one by one to install the rear shielding assembly 44 in the inner hole of the rotating body 1. The mounting holes 16 are designed as long slots, which can enable the rear shielding assembly 44 to be installed even when there is a certain circumferential error in the hole positions, reducing the manufacturing precision requirements. Further, on the inner surface of the rear shielding component 44, all mounting holes 16 are covered with a shielding plate 18. The shielding plate 18 is made of shielding material with a thickness of 1-2 mm. After the rear shielding component 44 and the rotating body 1 are installed, the covering screw 17 and the mounting hole 16 are covered to prevent radiation leakage at the mounting hole 16.

[0030] As Figure 21 and Figure 22 shown, the bottom of the radiation source component 5 has a beam outlet 24, a radiation source loop-shaped protrusion 25, and a radiation source loop-shaped groove 26. The surfaces of the beam outlet 24, the radiation source loop-shaped protrusion 25, and the radiation source loop-shaped groove 26 are all attached with shielding material. The thickness of the shielding layer of the radiation source loop-shaped groove 26 is 2-4 mm. The top shielding layer 413 extends into the radiation source loop-shaped groove 26 to form a second radiation channel 27 with a U-shaped cross-section. The gap between the inner side wall of the radiation source loop-shaped groove 26 and the top shielding layer 413 is 4-8 mm, the gap between the outer side wall of the radiation source loop-shaped groove 26 and the top shielding layer 413 is 4-8 mm, and the gap between the bottom surface of the radiation source loop-shaped groove 26 and the top shielding layer 413 is 0.5-2 mm. The non-contact docking between the upper shielding component 41 and the radiation source component 5 allows a certain gap to be maintained between the upper shielding component 41 and the radiation source component 5, facilitating fine adjustment of the position of the radiation source component 5. The U-shaped second radiation channel 27 enables the radiation to undergo multiple refractions and be absorbed by the radiation channel. After passing through the U-shaped radiation channel, the radiation undergoes more refractions and thus more radiation is absorbed.

[0031] As Figure 20 shown, the rotating body 1 is installed on the CT fixed frame 19. The front shielding component 43 and the rear shielding component 44 are respectively docked with the first over-packaging channel 20 and the second over-packaging channel 21. A baffle 22 and a retaining ring 23 are installed on the side of the first over-packaging channel 20 and the second over-packaging channel 21 close to the rotating body 1. The opening of the front shielding component 43 and the rear shielding component 44 is covered by the baffle 22, and the opening edge of the front shielding component 43 and the rear shielding component 44 is circumferentially wrapped by the retaining ring 23. Both the baffle 22 and the retaining ring 23 are attached with shielding material with a thickness of 2-5 mm. The radial gap between the retaining ring 23 and the front and rear shields, the axial gap between the baffle 22 and the front and rear shields, and the overlapping depth between the retaining ring 23 and the front and rear shields are all 9-16 mm. This structure can leave a certain safety gap with the channel during CT rotation, and the radiation channel at the overlapping part can effectively absorb the scattered radiation leaked at the docking part.

[0032] The above is only the preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution of the present invention and its inventive concept, makes equivalent substitutions or changes, and all should be covered within the protection scope of the present invention.

Claims

1. A radiation shielding device for security inspection CT, comprising a rotating body (1) with a central inner hole. A rotating bracket (2) and a detector (3) are installed on one end face of the rotating body (1) in an up-and-down distribution. A shielding cylinder (4) is installed in the inner hole of the rotating body (1). The shielding cylinder (4) is assembled and connected with the rotating bracket (2) and the detector (3), and both ends of the shielding cylinder (4) are used to dock with external channels. A ray source assembly (5) is installed at the upper end of the rotating bracket (2). Rays are emitted into the shielding cylinder (4) through the ray source assembly (5), and ray signals are received by the detector (3). It is characterized in that: Short arc-shaped openings (9) and long arc-shaped openings (10) for rays to enter and exit are respectively formed on the upper surface and the lower surface of the shielding cylinder (4). The upper surface of the shielding cylinder (4) has a flared opening that docks with the rotating bracket (2). The top opening of the flared opening is smaller than the bottom opening, and the top opening of the flared opening has a return-shaped portion that docks with the ray source assembly (5). The fan-shaped rays emitted by the ray source assembly (5) are received through the flared opening and prevented from leaking outwards. Both sides of the shielding cylinder (4) have extended portions extending outwards. The two extended portions are symmetrically arranged on both side edges of the long arc-shaped opening (10) to form a first inverted V-shaped opening. Axially, the first inverted V-shaped opening is opposite to the short arc-shaped opening (9), and the width of the first inverted V-shaped opening is greater than the width of the short arc-shaped opening. The fan-shaped rays emitted from the flared opening are converged to the long arc-shaped opening (10) through the first inverted V-shaped opening and received by the detector (3).

2. The radiation shielding device for security inspection CT according to claim 1, characterized in that, The rotating bracket (2) includes a bracket body (201). The upper end of the bracket body (201) has a second inverted V-shaped opening (206) adapted to the flared opening, and the opening of the second inverted V-shaped opening (206) extends upwards to form a bracket return-shaped protrusion (207). The upper end face of the rotating bracket (2) has a bracket return-shaped groove (208) located outside the bracket return-shaped protrusion (207) to form a U-shaped interface for docking with the ray source assembly (5).

3. A radiation shielding device for security inspection CT according to claim 1, characterized in that, The shielding cylinder (4) includes an upper shielding component (41), a lower shielding component (42), a front shielding component (43), a rear shielding component (44), and a slit shielding ring (45). The upper shielding component (41) and the lower shielding component (42) are respectively installed on the inner walls of the rotating bracket (2) and the detector (3), and the upper shielding component (41) and the lower shielding component (42) are assembled with each other to form a first ray channel (14). The front shielding component (43) is installed on the front end faces of the rotating bracket (2) and the detector (3). The docking seams of the upper shielding component (41), the lower shielding component (42), and the front shielding component (43) are covered by the slit shielding ring (45). The rear shielding component (44) is installed in the inner hole of the rotating body (1) and is lap-jointed with the rear edge of the upper shielding component (41) and the lower shielding component (42).

4. A radiation shielding device for security inspection CT according to claim 3, characterized in that, The upper shielding component (41) includes a semicircular-arc-shaped base shielding layer (411), a flared opening shielding layer (412), and a loop-shaped top shielding layer (413). The base shielding layer (411) is covered and installed on the inner wall of the rotating bracket (2). A short arc-shaped opening (9) is formed at the top of the base shielding layer (411). The opening shielding layer (412) is installed on the upper surface of the base shielding layer (411) and covers the outside of the short arc-shaped opening (9). The top shielding layer (413) is installed at the upper end opening of the opening shielding layer (412).

5. The radiation shielding device for security inspection CT according to claim 4, characterized in that, A first strengthening layer (414) located around the short arc-shaped opening (9) is installed on the lower surface of the base shielding layer (411). Outer convex extensions are provided on both inner side surfaces of the two ends of the base shielding layer (411). The two extensions are symmetrical to form a third eight-shaped opening, and a second strengthening layer (415) is installed on the inner wall of the third eight-shaped opening.

6. The radiation shielding device for security inspection CT according to claim 3, characterized in that, The detector (3) includes a detector body (301) that is semicircular-ring-shaped and installed at the lower end of the inner hole of the rotating body (1). The detector body (301) has a detector opening. Through the detector opening, the inner arc surface of the detector body (301) is divided into a detector first inner arc surface (302) and a detector second inner arc surface (303). The top edges at both ends of the detector body (301) sink to form a detector step portion (304). The lower shielding component (42) is covered and installed on the outer surfaces of the detector first inner arc surface (302), the detector second inner arc surface (303), and the detector step portion (304), and the shape of the lower shielding component (42) is consistent with the inner arc surface and the top of the detector body (301).

7. A radiation shielding device for security inspection CT according to claim 6, characterized in that, A long arc-shaped opening (10) that is consistent with the detector opening is formed on the lower shielding component (42). The long arc-shaped opening (10) divides the lower shielding component (42) into a lower shielding first inner arc surface (421) and a lower shielding second inner arc surface (422). The lower shielding first inner arc surface (421) and the lower shielding second inner arc surface (422) respectively correspond to the detector first inner arc surface (302) and the detector second inner arc surface (303). Both ends of the lower shielding component (42) have lower shielding step portions (423), and the lower shielding step portions (423) correspond to and are snap-fitted with the detector step portions (304).

8. The radiation shielding device for security inspection CT according to claim 3, characterized in that, The front shielding component (43) includes a support plate (431) installed on the front end surfaces of the rotating bracket (2) and the detector (3). A support ring (432) that is coaxially centered and has the same diameter as the support plate (431) is installed on the support plate (431). A protective ring (433) is installed on the inner wall of the support ring (432).

9. The radiation shielding device for security inspection CT according to claim 3, characterized in that, The rear shielding component (44) includes an upper half-ring body and a lower half-ring body with equal arc degrees; The upper half-ring body includes an upper support ring (441) and an upper protective ring (442) that is covered and installed on the inner wall of the upper support ring (441). The front end of the upper support ring (441) extends to the outside of the upper protective ring (442) to form an upper skirt (443) that docks with the upper shielding component (41); The lower semi-circular body includes a lower support ring (445) and a lower protective ring (446) covering and installed on the inner wall of the lower support ring (445). The front end of the lower support ring (445) extends to the outside of the lower protective ring (446) to form a lower skirt (447) for docking with the lower shielding component (42). Both sides of the upper protective ring (442) extend to the outside of both ends of the upper support ring (441) to form a circumferential skirt (444). When the upper semi-circular body and the lower semi-circular body are spliced, the circumferential skirt (444) overlaps on the inner surface of the lower protective ring (446) to prevent ray leakage at the docking joint.

10. A radiation shielding device for security inspection CT according to claim 9, characterized in that, Multiple columns of circumferentially distributed mounting holes (16) are provided on the inner walls of the upper semi-circular body and the lower semi-circular body. The upper semi-circular body and the lower semi-circular body are fixed to the inner wall of the inner hole of the rotating body (1) by screws (17), and a shutter (18) covering the openings of the mounting holes (16) is installed on the inner walls of the upper semi-circular body and the lower semi-circular body.

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