Pseudo-prosthesis for repairing maxillary defect

Abstract

The invention provides a prosthesis for repairing maxilla defects, and belongs to the technical field of prostheses. In order to solve the problem that an existing prosthesis is installed in an oral cavity, a residual maxillary bone in the oral cavity of a patient and residual teeth on the residual maxillary bone are connected with a maxillary prosthesis in a matched mode through a residual maxillary bone defect area, and artificial teeth are connected to the maxillary prosthesis; the maxillary prosthesis is fixedly connected with a metal palate plate, the metal palate plate is attached to the surface of the remaining maxillary mucosa, and the upper portion of the maxillary prosthesis covers and is attached to the lower end of the remaining maxillary; the subperiosteal implant is implanted on the lower surface of the remaining upper jaw palate with thin sclerotin, and a stable foundation is provided for installation of the prosthesis through the penetrating structure; the maxillary prosthesis is installed on the subperiosteal implant penetrating structure through the magnetic connecting mechanisms, the multiple magnetic connecting structures are installed stably, meanwhile, the magnetic connecting structures are convenient to detach to clean the oral cavity and the maxillary prosthesis, and the oral cavity environment is kept sanitary.

Description

Technical Field

[0001] The present invention relates to the technical field of prostheses, and in particular to a prosthesis for repairing maxillary defects. Background Art

[0002] Maxillary prosthesis is a device used to repair defects in the maxillary bone and adjacent hard and soft tissues. Its main functions include blocking the oral and nasal cavity, restoring the shape and function of the palate, and improving pronunciation, swallowing and chewing functions. Depending on the stage of repair, the prosthesis can be divided into transitional prosthesis and formal prosthesis. Transitional prosthesis is usually used in the early postoperative period and is replaced with a formal prosthesis after the wound heals.

[0003] For example, publication number CN100571662C discloses a prosthesis for repairing maxillary defects and a preparation method thereof, which includes a silicone rubber outer layer adapted to the maxillary defect area, an inner layer of a cylindrical skin and soft tissue expander provided within the silicone rubber outer layer, the inner layer of the cylindrical skin and soft tissue expander being connected to an inflation device extending to the outside of the silicone rubber outer layer, and corresponding magnetic retainers being provided on the silicone rubber outer layer and the inner layer of the cylindrical skin and soft tissue expander or the inflation device.

[0004] For example, publication number CN213430799U discloses a prosthesis for repairing maxillary bone defects, comprising a prosthesis body and an annular connector, wherein the annular connector is embedded in the prosthesis body to form a clamping force on the side wall of the prosthesis body; the annular connector can resist the force exerted on the prosthesis by lateral chewing, so as to satisfy the support of the vertical occlusal force while ensuring that the prosthesis forms a good oral and nasal cavity seal while exercising the normal chewing function, thereby restoring the patient's oral and maxillary function to the greatest extent. When worn in the mouth, the prosthesis fits tightly with the surrounding tissues such as the alveolar bone, gums, and soft palate, making it difficult to clean thoroughly. Long-term wearing and use may lead to deterioration of oral hygiene and increase the risk of oral diseases such as gingivitis and periodontitis. Some prostheses are installed in the patient's mouth by magnetic attraction. The magnetic attraction structure is easy to disassemble, but has limited stability, which easily leads to a decrease in retention force, making it unfavorable for long-term stable installation and use in the mouth.

[0005] In summary, it is particularly important to design a prosthesis that is stable to install and easy to disassemble and clean the internal oral environment. Summary of the Invention

[0006] The purpose of the present invention is to overcome the problem that the prosthesis worn in the oral cavity fits tightly with the surrounding tissues such as the alveolar bone, gums, soft palate, etc., is difficult to clean thoroughly, and long-term wearing and use may lead to deterioration of oral hygiene and increase the risk of oral diseases such as gingivitis and periodontitis. Some prostheses are installed in the patient's mouth by magnetic attraction. The magnetic structure is easy to disassemble, but the stability is limited, which easily leads to a decrease in retention force, which is not conducive to long-term stable installation and use in the oral cavity. At the same time, a prosthesis is designed that is stable to install and easy to disassemble to clean the internal environment of the oral cavity.

[0007] In order to achieve the above-mentioned purpose, the technical idea adopted by the present invention is: to solve the problem of installation of prostheses in the oral cavity in the prior art, and to maximize the stability of the prosthesis installed in the oral cavity, the remaining maxillary bone and the maxillary prosthesis are magnetically connected for installation, the mounting seat on the maxillary prosthesis is longitudinally magnetically connected to the subperiosteal implant penetration structure on the remaining maxillary bone, and the arc-shaped magnetic rod on the maxillary prosthesis is horizontally magnetically connected to the subperiosteal implant penetration structure. Through multiple magnetic suction methods, the maxillary prosthesis is stably installed, and the maxillary prosthesis can be conveniently disassembled for cleaning. At the same time, it is also convenient to clean the inside of the oral cavity, avoiding the risk of oral diseases such as gingivitis and periodontitis caused by improper cleaning of the patient's oral environment.

[0008] Based on the above technical ideas, the technical solution adopted by the present invention is: A prosthesis for repairing maxillary defects comprises the remaining maxillary bone in the patient's oral cavity and the remaining teeth on the remaining maxillary bone, the remaining maxillary bone defect area being cooperatively connected to the maxillary prosthesis, and the maxillary prosthesis being connected to artificial teeth; a metal palate plate being fixedly connected to the maxillary prosthesis, the metal palate plate being adhered to the mucosal surface of the remaining maxillary bone, and the lower end of the maxillary prosthesis being covered and adhered to the lower end of the remaining maxillary bone; an assembly mechanism being mounted on the surface of the remaining maxillary bone; a reinforcement mechanism being mounted on the surface of the metal palate plate; wherein the assembly mechanism is used to mount the maxillary prosthesis on the remaining maxillary bone, and the reinforcement mechanism is used to increase the stability of the assembly of the maxillary prosthesis and the remaining maxillary bone.

[0009] A further limitation of the above technical solution is that the assembly mechanism includes a subperiosteal implant penetration structure implanted on the surface of the remaining maxillary bone; the external fixation sleeve of the subperiosteal implant penetration structure is provided with a metal mesh, the metal mesh is covered under the periosteum of the remaining maxillary surface, and small screws are installed on the metal mesh to fix it to the remaining maxillary bone.

[0010] A further limitation of the above technical solution is that the circular groove is provided on the maxillary prosthesis and the metal palate plate, and the subperiosteal implant penetration structure is distributed correspondingly to the coaxial line of the circular groove.

[0011] To further limit the above technical solution, the reinforcement mechanism includes a plurality of small connectors fixedly connected to the metal palate plate, a plurality of clasps are fixedly installed on the small connectors, and the clasps are sleeved on the outside of the teeth.

[0012] As a further limitation of the above technical solution, the maxillary prosthesis is internally provided with a magnetic connection mechanism for assembling with the subperiosteal implant penetration structure.

[0013] As a further limitation of the above technical solution, the magnetic connection mechanism includes a mounting seat fixed in the maxillary prosthesis, and the mounting seat is correspondingly arranged at a position directly below the subperiosteal implant penetration structure.

[0014] To further limit the above technical solution, the magnetic connection mechanism also includes a mounting magnetic groove opened in the mounting seat; the external fixing sleeve of the subperiosteal implant penetration structure is provided with a magnetic sleeve, and the mounting magnetic groove in the mounting seat is magnetically engaged with the magnetic sleeve.

[0015] A further limitation of the above technical solution is that a reinforcement column is fixedly connected to the mounting seat along the central axis direction, the reinforcement column is made of elastic material and the upper end side is inclined; a reinforcement groove is opened in the subperiosteal implant penetration structure along the axial direction, and the reinforcement column is engaged and connected to the reinforcement groove with interference fit.

[0016] To further limit the above technical solution, the positioning disk is fixedly installed on the lower end surface of the maxillary prosthesis, and an arc-shaped guide groove is provided in the positioning disk, and an arc-shaped magnetic rod is slidably connected in the positioning disk along the direction of the arc-shaped guide groove; a limiting disk is fixedly installed at one end of the arc-shaped magnetic rod located inside the positioning disk, the diameter of the limiting disk is larger than the diameter of the arc-shaped magnetic rod, and the limiting disk is slidably connected in the arc-shaped guide groove.

[0017] Further limitation of the above technical solution is that the subperiosteal implant penetrates the structure, and an arc-shaped magnetic groove is opened inside, and the arc-shaped magnetic rod slides and is magnetically engaged with the arc-shaped magnetic groove; a side groove is opened on the side of the mounting seat close to the arc-shaped magnetic rod, and the side groove is connected with the arc-shaped magnetic groove.

[0018] Compared with the prior art, the present invention has the following beneficial effects: (1) Stable installation base: The subperiosteal implant is placed on the lower surface of the remaining maxillary palate where the bone is thinner, and a stable base is provided for the installation of the prosthesis through the penetrating structure.

[0019] (2) Easy to disassemble and clean: The maxillary prosthesis is magnetically connected to the subperiosteal implant through the mounting seat, mounting magnetic groove, magnetic sleeve and the subperiosteal implant penetration structure. Patients can remove the maxillary prosthesis from the oral cavity by themselves, clean the oral cavity and the maxillary prosthesis, and avoid the risk of oral diseases such as gingivitis and periodontitis.

[0020] (3) Magnetic stability: The mounting base and the subperiosteal implant penetration structure are interference-fitted through the reinforcement column and the reinforcement groove. On the basis of magnetic adsorption, the interference fit can further improve the stability of the connection between the maxillary prosthesis and the subperiosteal implant penetration structure.

[0021] (4) Reinforced installation: The maxillary prosthesis is further magnetically adsorbed between the positioning plate, the arc-shaped magnetic rod and the subperiosteal implant penetration structure. The arc-shaped magnetic rod slides along the direction of the arc-shaped guide groove, so that the arc-shaped magnetic rod moves and engages into the arc-shaped magnetic groove opened inside the subperiosteal implant penetration structure. Through the lateral magnetic adsorption between the arc-shaped magnetic rod and the arc-shaped magnetic groove, the connection between the maxillary prosthesis and the subperiosteal implant penetration structure can be further reinforced. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 The present invention is a schematic diagram of a maxillary prosthesis for repairing maxillary defects and the remaining maxillary structure.

[0024] Figure 2 The present invention is a schematic diagram of the structure of a metal palate plate prosthesis for repairing maxillary defects.

[0025] Figure 3 The present invention is a schematic diagram of a clasp structure of a prosthesis for repairing maxillary defects.

[0026] Figure 4 The present invention is a schematic diagram of a subperiosteal implant penetration structure of a prosthesis for repairing maxillary bone defects.

[0027] Figure 5 The figure is a schematic diagram of the structure of a subperiosteal implant of a prosthesis for repairing maxillary bone defects according to the present invention.

[0028] Figure 6 The present invention is a schematic diagram of the structure of a maxillary prosthesis for repairing maxillary bone defects.

[0029] Figure 7 The figure is a schematic diagram of a mounting seat of a prosthesis for repairing maxillary defects according to the present invention.

[0030] Figure 8 The figure is a schematic structural diagram of a positioning plate of a prosthesis for repairing maxillary defects according to the present invention.

[0031] Figure 9 The figure is a schematic diagram of the arc-shaped magnetic rod structure of a prosthesis for repairing maxillary defects according to the present invention.

[0032] Figure 10 The present invention is a schematic cross-sectional view of a subperiosteal implant penetration structure of a prosthesis for repairing maxillary bone defects.

[0033] Figure 11 The figure is a schematic cross-sectional view of a positioning plate of a prosthesis for repairing maxillary defects according to the present invention.

[0034] Among them, 1. Remaining maxillary bone; 2. Teeth; 3. Maxillary prosthesis; 4. Artificial teeth; 5. Metal palate plate; 6. Subperiosteal implant penetration structure; 7. Small screws; 8. Metal mesh; 9. Small connector; 10. Clamp; 11. Circular groove; 12. Mounting seat; 13. Mounting magnetic groove; 14. Reinforcement column; 15. Reinforcement groove; 16. Positioning plate; 17. Arc-shaped guide groove; 18. Arc-shaped magnetic rod; 19. Limiting disc; 20. Arc-shaped magnetic groove; 21. Side groove; 22. Magnetic sleeve. DETAILED DESCRIPTION

[0035] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art will make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0036] Example 1 This embodiment provides a prosthesis for repairing maxillary defects, such as Figures 1-11 As shown, it includes the remaining maxillary bone 1 in the patient's mouth and the remaining teeth 2 on the remaining maxillary bone 1, the defect area of ​​the remaining maxillary bone 1 is connected with a maxillary prosthesis 3, and the maxillary prosthesis 3 is connected with artificial teeth 4; the maxillary prosthesis 3 is fixedly connected with a metal palate plate 5, the metal palate plate 5 is attached to the mucosal surface of the remaining maxillary bone 1, and the upper part of the maxillary prosthesis 3 is covered and attached to the lower end of the remaining maxillary bone 1; the remaining maxillary bone 1 is surface-mounted with an assembling mechanism; the metal palate plate 5 is surface-mounted with a reinforcing mechanism; wherein, the assembling mechanism is used to install the maxillary prosthesis 3 on the remaining maxillary bone 1, and the reinforcing mechanism is used to increase the stability of the assembly of the maxillary prosthesis 3 and the remaining maxillary bone 1.

[0037] The assembly mechanism includes a subperiosteal implant penetrating structure 6 implanted on the surface of the remaining maxillary bone 1; the external fixing sleeve of the subperiosteal implant penetrating structure 6 is provided with a metal mesh 8, on which small screws 7 fixed to the remaining maxillary bone 1 are installed.

[0038] The circular groove 11 is provided on the maxillary prosthesis 3 and the metal palate plate 5 , and the subperiosteal implant penetrating structure 6 is coaxially distributed with the circular groove 11 .

[0039] The reinforcement mechanism includes a plurality of small connectors 9 fixedly connected to the metal palate plate 5 , a plurality of clasps 10 are fixedly mounted on the small connectors 9 , and the clasps 10 are sleeved on the outside of the teeth 2 .

[0040] Before preparing the maxillary prosthesis 3, a subperiosteal implant is first placed in the patient's mouth. The metal mesh 8 on the outside of the subperiosteal implant penetration structure 6 is fitted to the surface of the remaining maxillary bone 1 and secured to the surface of the remaining maxillary bone 1 using multiple small screws 7. This defines the position of the subperiosteal implant penetration structure 6 and provides a stable foundation for the installation of the maxillary prosthesis 3. After the surgical area heals, a maxillary prosthesis 3 is prepared to match the defective area of ​​the remaining maxillary bone 1 based on the morphology of the remaining maxillary bone 1 in the patient's mouth. The maxillary prosthesis 3 is then installed in the patient's mouth, with the circular groove 11 on the maxillary prosthesis 3 fitting over the outside of the subperiosteal implant penetration structure 6.

[0041] Before preparing the prosthesis, the morphology of the patient's teeth 2 is scanned, several teeth 2 are selected, and clasps 10 matching the teeth 2 are prepared. The clasps 10 are fixedly connected to the metal palate plate 5 through a small connector 9. Under the clamping force of the clasps 10 and the teeth 2, the maxillary prosthesis 3 can be stably installed in the patient's mouth.

[0042] Example 2 This embodiment provides a prosthesis for repairing maxillary defects and also discloses a magnetic connection mechanism. The maxillary prosthesis 3 is internally provided with a magnetic connection mechanism assembled with a subperiosteal implant penetration structure 6 .

[0043] The magnetic connection mechanism includes a mounting seat 12 fixed in the maxillary prosthesis 3 , and the mounting seat 12 is correspondingly arranged at a position just below the subperiosteal implant penetration structure 6 .

[0044] The magnetic connection mechanism also includes a mounting magnetic groove 13 provided in the mounting seat 12; the external fixing sleeve of the subperiosteal implant penetrating structure 6 is provided with a magnetic sleeve 22, and the mounting magnetic groove 13 in the mounting seat 12 is magnetically engaged with the magnetic sleeve 22.

[0045] A reinforcement column 14 is fixedly connected to the mounting seat 12 along the central axis direction. The reinforcement column 14 is made of elastic material and has an inclined upper end side. A reinforcement groove 15 is opened in the subperiosteal implant penetration structure 6 along the axial direction. The reinforcement column 14 is engaged and interference fit with the reinforcement groove 15.

[0046] The positioning disk 16 is fixedly mounted on the lower end surface of the maxillary prosthesis 3, and an arc-shaped guide groove 17 is provided in the positioning disk 16, and an arc-shaped magnetic rod 18 is slidably connected to the positioning disk 16 along the direction of the arc-shaped guide groove 17; a limiting disk 19 is fixedly mounted on one end of the arc-shaped magnetic rod 18 located inside the positioning disk 16, and the diameter of the limiting disk 19 is larger than the diameter of the arc-shaped magnetic rod 18, and the limiting disk 19 is slidably connected to the arc-shaped guide groove 17.

[0047] The subperiosteal implant penetrates the structure 6, and an arc-shaped magnetic groove 20 is opened inside. The arc-shaped magnetic rod 18 slides and is magnetically engaged with the arc-shaped magnetic groove 20; a side groove 21 is opened on the side of the mounting seat 12 close to the arc-shaped magnetic rod 18, and the side groove 21 is connected to the arc-shaped magnetic groove 20.

[0048] During the installation process of the maxillary prosthesis 3, the mounting seat 12 fixed inside it is sleeved on the outside of the subperiosteal implant penetrating structure 6, and the mounting magnetic groove 13 in the mounting seat 12 is magnetically connected to the magnetic sleeve 22 outside the subperiosteal implant penetrating structure 6. Through this magnetic connection structure, the installation position of the maxillary prosthesis 3 in the oral cavity can be preliminarily installed and limited.

[0049] During the process of magnetic connection between the mounting seat 12 and the subperiosteal implant penetration structure 6, the reinforcement column 14 in the mounting seat 12 moves and extends into the reinforcement groove 15 in the subperiosteal implant penetration structure 6, and the upper half of the inclined surface of the reinforcement column 14 first contacts and squeezes the edge of the opening of the reinforcement groove 15. Since the diameter of the lower half of the reinforcement column 14 is slightly larger than the internal diameter of the reinforcement groove 15, and the reinforcement column 14 is made of elastic material, when the lower half of the reinforcement column 14 enters the reinforcement groove 15, the lower half of the reinforcement column 14 is squeezed and interference fits with the inside of the reinforcement groove 15, so that the maxillary prosthesis 3 can be installed more stably under the remaining maxillary bone 1.

[0050] Finally, the arc-shaped magnetic rod 18 is slid along the opening direction of the arc-shaped guide groove 17, so that the arc-shaped magnetic rod 18 moves close to the subperiosteal implant penetration structure 6, and the arc-shaped magnetic rod 18 passes through the side groove 21 and moves into the arc-shaped magnetic groove 20 opened inside the subperiosteal implant penetration structure 6. At this time, the arc-shaped magnetic rod 18 is supported and connected between the maxillary prosthesis 3 and the subperiosteal implant penetration structure 6. The magnetic attraction between the arc-shaped magnetic rod 18 and the arc-shaped magnetic groove 20 can further improve the installation stability of the maxillary prosthesis 3. The magnetic connection structure is used for convenient disassembly. The patient can independently remove the maxillary prosthesis 3 from the oral cavity to clean the inside of the oral cavity and the maxillary prosthesis 3, avoiding the risk of oral diseases such as gingivitis and periodontitis due to improper cleaning.

[0051] The above content is a further detailed description of the present invention in conjunction with specific preferred embodiments, which is convenient for those skilled in the art to understand and apply the present invention. It cannot be determined that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art of the present invention, several simple deductions or substitutions can be made without departing from the concept of the present invention, without having to go through creative work. Therefore, based on the disclosure of the present invention, simple improvements made to the present invention by those skilled in the art should be within the scope of protection of the present invention.

Claims

1. A prosthesis for repairing a maxillary defect, comprising a remaining maxillary bone (1) in a patient's oral cavity and teeth (2) remaining on the remaining maxillary bone (1), characterized in that: The defective area of ​​the remaining maxillary bone (1) is connected with a maxillary prosthesis (3), and the maxillary prosthesis (3) is connected with an artificial tooth (4); The maxillary prosthesis (3) is fixedly connected with a metal palate plate (5), the metal palate plate (5) is attached to the mucosal surface of the remaining maxillary bone (1), and the upper part of the maxillary prosthesis (3) is covered and attached to the lower end of the remaining maxillary bone (1); The remaining maxillary bone (1) is provided with an assembly mechanism mounted on the surface; A metal palate plate (5) having a reinforcement mechanism mounted on its surface; The assembly mechanism is used to mount the maxillary prosthesis (3) on the remaining maxillary bone (1), and the reinforcement mechanism is used to increase the stability of the assembly of the maxillary prosthesis (3) and the remaining maxillary bone (1).

2. The prosthesis for repairing maxillary defects according to claim 1, characterized in that: An assembly mechanism comprising a subperiosteal implant-emergence structure (6) implanted into the palatal surface of the remaining maxillary bone (1); The external fixing sleeve of the subperiosteal implant penetrating structure (6) is provided with a metal mesh (8), which covers the subperiosteum of the surface of the remaining maxillary bone (1), and a small screw (7) fixed to the remaining maxillary bone (1) is installed on the metal mesh (8).

3. The prosthesis for repairing maxillary defects according to claim 2, characterized in that: The circular groove (11) is provided on the maxillary prosthesis (3) and the metal palate plate (5), and the subperiosteal implant penetrating structure (6) is coaxially distributed with the circular groove (11).

4. The prosthesis for repairing maxillary defects according to claim 1, characterized in that: The reinforcement mechanism comprises a plurality of small connectors (9) fixedly connected to the metal palate plate (5), a plurality of clasps (10) fixedly mounted on the small connectors (9), and the clasps (10) are sleeved on the outside of the teeth (2).

5. The prosthesis for repairing maxillary defects according to claim 1, characterized in that: The maxillary prosthesis (3) is provided with a magnetic connection mechanism assembled with the subperiosteal implant penetration structure (6) therein.

6. The prosthesis for repairing maxillary defects according to claim 5, characterized in that: The magnetic connection mechanism comprises a mounting seat (12) fixed in the maxillary prosthesis (3), wherein the mounting seat (12) is correspondingly arranged at a position directly below the subperiosteal implant penetration structure (6).

7. The prosthesis for repairing maxillary defects according to claim 6, characterized in that: The magnetic connection mechanism further includes a mounting magnetic groove (13) provided in the mounting seat (12); The external fixing sleeve of the subperiosteal implant penetrating structure (6) is provided with a magnetic sleeve (22), and the mounting magnetic groove (13) in the mounting seat (12) is magnetically engaged with the magnetic sleeve (22).

8. The prosthesis for repairing maxillary defects according to claim 7, characterized in that: A reinforcement column (14) is fixedly connected to the mounting seat (12) along the central axis direction. The reinforcement column (14) is made of elastic material, and the upper end side is inclined. A reinforcement groove (15) is provided in the subperiosteal implant penetration structure (6) along the axial direction, and the reinforcement column (14) is engaged with the reinforcement groove (15) and has an interference fit.

9. The prosthesis for repairing maxillary defects according to claim 8, characterized in that: A positioning plate (16) is fixedly mounted on the lower end surface of the maxillary prosthesis (3), and an arc-shaped guide slot (17) is provided in the positioning plate (16), and an arc-shaped magnetic rod (18) is slidably connected to the positioning plate (16) along the direction of the arc-shaped guide slot (17); A limiting disc (19) is fixedly mounted on one end of the arc-shaped magnetic rod (18) located inside the positioning disc (16); the diameter of the limiting disc (19) is larger than the diameter of the arc-shaped magnetic rod (18), and the limiting disc (19) is slidably connected to the arc-shaped guide slot (17).

10. The prosthesis for repairing maxillary defects according to claim 9, characterized in that: The subperiosteal implant penetrating structure (6) has an arc-shaped magnetic groove (20) formed therein, and the arc-shaped magnetic rod (18) slides and is magnetically engaged with the arc-shaped magnetic groove (20); A side groove (21) is provided on the mounting seat (12) on one side close to the arc-shaped magnetic rod (18), and the side groove (21) is connected to the arc-shaped magnetic groove (20).

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