Irradiation head structure of millimeter wave therapeutic instrument
By designing a millimeter-wave therapy head structure driven by a rotating ring and rolling elements, the problem that existing irradiation heads cannot simultaneously achieve precise local and large-area treatment has been solved, enabling rapid switching of treatment methods and improving efficiency.
Patent Information
- Application Number
- CN202511123633.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-12
- Publication Date
- 2025-10-31
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
The existing millimeter wave therapy device's irradiation head structure cannot simultaneously achieve precise local treatment and large-area treatment, and the switching of treatment modes is cumbersome, affecting treatment efficiency and effectiveness.
Design an irradiation head structure including a rotating ring, a supporting crossbeam, a movable frame, and a radiating head. The direction of the rotating ring is controlled by a motor, and the position of the radiating head is switched by rolling elements rolling in different grooves, so as to achieve rapid switching of treatment modes.
It enables millimeter wave therapy devices to quickly switch between single-area and large-area treatment, improving treatment efficiency and convenience, and meeting the needs of modern medicine for rapid, efficient, and precise treatment.
Smart Images

Figure CN120860486A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a millimeter-wave therapy device irradiation head structure, belonging to the field of medical device technology. Background Technology
[0002] In the current field of millimeter-wave therapy technology, common irradiation head designs often suffer from functional limitations and operational inconvenience. On the one hand, many traditional millimeter-wave therapy devices can only perform single-mode irradiation. They can only irradiate a large area, making it difficult to precisely target specific lesions and meet the need for high-intensity, targeted treatment of small lesions, resulting in poor treatment outcomes in cases requiring precise treatment. Alternatively, they can only focus on localized, small-area irradiation, failing to quickly and effectively expand the irradiation range when faced with large-area lesions requiring extensive coverage, increasing treatment time and patient discomfort. On the other hand, even if some devices offer different irradiation modes, switching between them is cumbersome. This typically requires complex mechanical adjustments, manual replacement of irradiation components, or tedious parameter settings. This demands high skill and experience from medical personnel, and the time-consuming switching process increases the risk of errors that could affect treatment effectiveness or even delay optimal treatment, causing significant inconvenience and reducing overall treatment efficiency. This fails to meet the demands of modern medicine for rapid, efficient, and precise treatment. Summary of the Invention
[0003] To address the aforementioned technical shortcomings, the purpose of this invention is to provide a millimeter-wave therapy head structure that meets the needs of both concentrated irradiation therapy on a single area and large-area irradiation therapy, and is applicable to various treatment scenarios.
[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: The present invention provides a millimeter wave therapy device irradiation head structure, comprising: shell; A rotating ring, which is rotatably connected to the inside of the outer casing; A support beam is laterally fixed to the rotating ring; A movable frame, which is slidably connected to the support beam along the length of the support beam; A radiating head, which is mounted on a movable frame; The movable frame is equipped with a rolling element via a first spring. A fixed plate is provided inside the outer shell. The lower surface of the fixed plate has an inner ring groove and an outer ring groove. A connecting groove is provided between the inner ring groove and the outer ring groove. The rolling element is rotatably connected in the inner ring groove or the outer ring groove. A step is provided at the bottom of the inner ring groove and the connection position of the connecting groove. A rotating plate is rotatably provided at the connection position of the outer ring groove and the connecting groove to separate the outer ring groove and the connecting groove.
[0005] Preferably, a swing rod is fixed on the rotating shaft of the rotating plate, a first connecting column is fixed at the end of the swing rod away from the rotating plate, a second connecting column is fixed on the side wall of the fixed plate, and a tension spring is provided between the first connecting column and the second connecting column; Under the tension of the tension spring, the swing rod drives the rotating plate to be placed horizontally in the outer ring groove, and the outer ring groove and the connecting groove are in a connected state.
[0006] Preferably, a rotating shaft is fixed on each of the two side walls of the radiating head, and the radiating head is rotatably connected to the movable frame through the two rotating shafts; A torsion spring is sleeved on the rotating shaft. One end of the torsion spring is fixed to the side wall of the radiating head, and the other end of the torsion spring is fixed to the moving frame. One end of the movable frame is fixedly connected to a top rod for pressing down the radiating head; When the rolling element rotates into the inner annular groove, the radiating head is in a vertically downward position; When the rolling element rolls from the connecting groove to the outer ring groove, the radiating head is pressed by the push rod, causing the radiating head to rotate against the torsion spring.
[0007] Preferably, a support frame is fixed in the middle of the support beam, a rotating block is fixed on the support frame, the rotating block is rotatably connected to the center of the fixed plate, a power receiving post is fixed in the center of the rotating block, and a spiral wire is connected between the power receiving post and the radiating head. A power transmission column is fixed inside the outer casing and above the fixed plate, and an external conductor is connected to the top of the power transmission column; The power receiving post has a slot inside, the lower end of the power transmission post is fixed with a plug, the plug is inserted into the slot, and multiple first conductive rings are fixed inside the slot, while multiple second conductive rings are fixed on the outer wall of the plug. When the plug is inserted into the slot, multiple first conductive rings make contact with multiple second conductive rings in a one-to-one correspondence.
[0008] Preferably, tracks are provided on both the upper and lower surfaces of the supporting beam, and multiple rollers are provided on the movable frame above and below the supporting beam, with the rollers tumbling within the corresponding tracks.
[0009] Preferably, a protective cover is provided at the bottom of the outer casing.
[0010] Preferably, a motor is fixed on the housing, and a gear is fixed on the output shaft of the motor, the gear meshing with the inner wall of the rotating ring; When the motor starts, the motor's output shaft drives the gear to rotate, and the gear drives the rotating ring to rotate inside the housing.
[0011] Preferably, the outer shell includes an upper shell and a lower shell, which are fixedly connected by bolts.
[0012] Preferably, a connecting frame is provided at the connection between the upper shell and the lower shell.
[0013] Preferably, positioning plates are fixed on both sides of the fixed plate, and positioning grooves are provided on both sides of the inner wall of the lower shell; When the plate is installed into the housing, the positioning plate is inserted into the positioning slot to fix the plate in place.
[0014] Compared with existing technologies: 1. In this invention, when the movable frame is in the middle of the supporting beam and the radiating head is in the center of the outer shell, the motor is started to make the rotating ring drive the relevant components to rotate in the direction of a specific arrow. The rolling parts roll in the inner ring groove and are not affected by the steps. The radiating head can rotate on its own in the center of the outer shell, and concentrate on irradiating a single area to treat it, thus meeting the needs of precise treatment for local diseases.
[0015] 2. This invention uses a motor to make the rotating ring rotate in the opposite direction of the arrow. When the rolling element rolls to the connection between the inner ring groove and the connecting groove, it is blocked by the step and enters the outer ring groove. The moving frame drives the radiation head to move off the center of the outer shell on the support beam. Then the rolling element rotates in the outer ring groove. When it reaches the connection point after one revolution around the outer ring groove, the top plate separates the outer ring groove and the connecting groove, so that the radiation head can rotate around the center line of the outer shell at the off-center position, realizing large-area irradiation treatment. It is suitable for scenarios that require extensive coverage treatment.
[0016] 3. This invention enables rapid switching between treatment modes. When switching between single-area irradiation therapy and large-area irradiation therapy, it is only necessary to control the motor to change the rotation direction of the rotating ring. The rolling element can then move from the outer ring groove along the connecting groove into the inner ring groove or from the inner ring groove along the connecting groove into the outer ring groove. Without complicated operations or additional devices, the change in treatment mode can be completed quickly, improving treatment efficiency and bringing great convenience to patients and medical staff. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of the structure of the present invention.
[0018] Figure 2 This is a cross-sectional view of the entire invention. Figure 1 .
[0019] Figure 3 This is a cross-sectional view of the entire invention. Figure 2 .
[0020] Figure 4 This is an exploded cross-sectional view of the entire invention.
[0021] Figure 5 This is an exploded cross-sectional view of the support beam and the movable frame of the present invention.
[0022] Figure 6 This is a schematic diagram of the structure of the movable frame, rolling element and fixed plate of the present invention.
[0023] Figure 7 For the present invention Figure 6 Enlarged view of point A.
[0024] Figure 8 This is a cross-sectional view of the fixed plate, rotating plate, swing rod and tension spring of the present invention.
[0025] Figure 9 This is a cross-sectional view of the power connection post, slot, spiral wire, power transmission post and plug of the present invention.
[0026] Figure 10 This is a cross-sectional view of the supporting beam, movable frame, radial head, and top rod of the present invention.
[0027] In the picture: 1. Outer shell; 101. Upper shell; 102. Lower shell; 103. Connecting frame; 2. Rotating ring; 201. Motor; 202. Gear; 3. Support beam, 301. Track, 302. Support frame, 303. Rotating block; 4. Moving frame, 401, rollers; 5. Radiation head; 501. Rotating shaft; 502. Torsion spring; 6. Rolling parts; 7. Fixed plate; 701. Inner ring groove; 702. Outer ring groove; 703. Connecting groove; 704. Step; 705. Rotating plate; 706. Swing rod; 707. First connecting column; 708. Second connecting column; 709. Tension spring. 8. First spring; 9. Push rod; 10. Positioning plate; 11. Positioning groove; 12. Protective cover; 13. Connecting post; 1301. Slot; 1302. First conductive ring; 14. Spiral wire; 15. Transmission post; 1501. Plug; 1502. Second conductive ring; 16. External wire. Detailed Implementation
[0028] The present invention is illustrated below with specific embodiments, but these are not intended to limit the invention.
[0029] Example 1 like Figures 1-10 As shown in this embodiment, a millimeter-wave therapy device irradiation head structure is provided, including a shell 1, a rotating ring 2, a supporting crossbeam 3, a movable frame 4, and a radiating head 5. The specific structure and connection relationship of each component are as follows: The outer casing 1 serves as the external protective component of the entire irradiation head structure. The outer casing 1 includes an upper casing 101 and a lower casing 102, which are fixedly connected by bolts. A connecting bracket 103 is provided at the connection point to enhance the stability of the connection. A protective cover 12 is provided at the bottom of the outer casing 1 to protect the internal components and prevent external impurities from entering.
[0030] The rotating ring 2 is rotatably connected inside the housing 1. To drive the rotating ring 2 to rotate, a motor 201 is fixed on the housing 1, and a gear 202 is fixed on the output shaft of the motor 201. The gear 202 meshes with the inner wall of the rotating ring 2. When the motor 201 starts, the output shaft of the motor 201 drives the gear 202 to rotate, and the gear 202 drives the rotating ring 2 to rotate inside the housing 1.
[0031] The support beam 3 is horizontally fixed on the rotating ring 2 and rotates together with the rotating ring 2. Tracks 301 are provided on both the upper and lower surfaces of the support beam 3 to facilitate the sliding of the movable frame 4.
[0032] The movable frame 4 is slidably connected to the support beam 3 along the length of the support beam 3. Multiple rollers 401 are provided on the movable frame 4 above and below the support beam 3. The rollers 401 are slidably connected in the corresponding tracks 301 to reduce the frictional resistance when the movable frame 4 slides.
[0033] The radiation head 5 is mounted on the mobile frame 4 and is used to emit millimeter waves for treatment.
[0034] In addition, to enable the movable frame 4 to switch the position of the radiating head 5, the structure also includes the following components: A rolling element 6 is provided on the movable frame 4 via a first spring 8. The first spring 8 has a spring force that pushes the rolling element 6 toward the fixed plate 7, so that the end of the rolling element 6 can slide tightly against the bottom of the groove of the fixed plate 7.
[0035] The outer casing 1 is provided with a fixed plate 7. The lower surface of the fixed plate 7 is provided with an inner ring groove 701 and an outer ring groove 702 that are concentrically arranged. A connecting groove 703 is provided between the inner ring groove 701 and the outer ring groove 702. The rolling element 6 is tumblingly connected in the inner ring groove 701 or the outer ring groove 702.
[0036] The bottom of the inner ring groove 701 is provided with a step 704 at the connection position between it and the connecting groove 703, and the outer ring groove 702 is provided with a rotating plate 705 at the connection position between it and the connecting groove 703 to separate the outer ring groove 702 from the connecting groove 703.
[0037] The specific structure and working status of the 705 converter plate are as follows: Combination Figure 6 and Figure 8 As shown, a swing rod 706 is fixed on the rotating shaft of the rotating plate 705. A first connecting column 707 is fixed at the end of the swing rod 706 away from the rotating plate 705. A second connecting column 708 is fixed on the side wall of the fixed plate 7. A tension spring 709 is provided between the first connecting column 707 and the second connecting column 708.
[0038] Under the tension of the tension spring 709, the swing rod 706 drives the rotating plate 705 to be placed horizontally in the outer annular groove 702. At this time, the outer annular groove 702 and the connecting groove 703 are in a connected state, that is, the rotating plate 705 is in a position as shown in the figure. Figure 6 The state shown.
[0039] One end of the rotating plate 705 rotates to the connection position between the outer annular groove 702 and the connecting groove 703, and the other end is a swing end. When the swing end of the rotating plate 705 rotates toward the connecting groove 703, the rotating plate 705 separates the outer annular groove 702 from the connecting groove 703; when the swing end of the rotating plate 705 rotates away from the connecting groove 703, the outer annular groove 702 and the connecting groove 703 are connected, and the rotating plate 705 is blocked in the outer annular groove 702.
[0040] Figure 6 The label has an arrow, and the rolling element 6 can roll in the direction of the arrow or the opposite direction in the inner ring groove 701 or the outer ring groove 702. The following description of rolling in the direction of the arrow and the opposite direction of the arrow refers to the arrow.
[0041] To facilitate the installation and fixation of the mounting plate 7, positioning plates 10 are fixed on both sides of the mounting plate 7, and positioning grooves 11 are provided on both sides of the inner wall of the lower shell 102. When the upper shell 101 is separated from the lower shell 102, the mounting plate 7 can be inserted from the top of the lower shell 102; when the mounting plate 7 is installed into the outer shell 1, the positioning plates 10 are inserted into the positioning grooves 11 to fix the mounting plate 7.
[0042] The usage of this embodiment is as follows: Method 1 (Concentrated Irradiation): The movable frame 4 is positioned in the middle of the supporting beam 3, and the radiating head 5 is located at the center of the outer casing 1. At this time, the motor 201 is activated, causing the rotating ring 2 to rotate along with the supporting beam 3, the movable frame 4, and the radiating head 5 in the direction of the arrow. The rolling element 6 is rolled within the inner ring groove 701. During this process, the rolling element 6 is in the process of descending the step 704, unaffected by the step 704 in the inner ring groove 701. The radiating head 5 rotates at the center of the outer casing 1, concentrating irradiation treatment on a single area.
[0043] Method 2 (Large Area Irradiation): Start motor 201, causing rotating ring 2, along with supporting beam 3, moving frame 4, and radiating head 5, to rotate in the opposite direction of the arrow. Rolling element 6 will also rotate in the opposite direction. When rolling element 6 reaches the connection between inner ring groove 701 and connecting groove 703, it is blocked by step 704 and will enter the outer ring groove 702 along connecting groove 703. At this time, moving frame 4, carrying radiating head 5, moves on supporting beam 3, causing radiating head 5 to deviate from the center position of outer shell 1. As rotating ring 2 continues to rotate in the opposite direction of the arrow, rolling element 6 rotates in the opposite direction of the arrow within outer ring groove 702. When the rolling element 6 rotates once around the outer ring groove 702 and reaches the position where the outer ring groove 702 meets the connecting groove 703, the rolling element 6 presses against the rotating plate 705 to rotate. The rotating plate 705 blocks the connection between the outer ring groove 702 and the connecting groove 703, so that the rolling element 6 continues to rotate within the outer ring groove 702. The radiation head 5 can rotate around the center line of the outer shell 1 at a position deviating from the center of the outer shell 1, thereby achieving large-area irradiation treatment.
[0044] Referring to the above description, the present invention enables rapid switching of treatment methods. When switching between single-area irradiation therapy and large-area irradiation therapy, it is only necessary to control the motor 201 to change the rotation direction of the rotating ring 2. The rolling element 6 can then move from the outer ring groove 702 along the connecting groove 703 into the inner ring groove 701 or from the inner ring groove 701 along the connecting groove 703 into the outer ring groove 702. Without complicated operations or additional devices, the change of treatment method can be completed quickly, improving treatment efficiency and bringing great convenience to patients and medical staff.
[0045] Example 2 like Figures 2-5 as well as Figure 10 As shown, based on Embodiment 1, this embodiment improves the structure of the radiator 5, enabling the radiator 5 to adjust the irradiation angle according to position changes. The specific structure is as follows: Rotating shafts 501 are fixed on both sides of the radiator 5. The radiator 5 is rotatably connected to the movable frame 4 through the two rotating shafts 501, so that the radiator 5 can rotate around the rotating shafts 501.
[0046] A torsion spring 502 is sleeved on the rotating shaft 501. One end of the torsion spring 502 is fixed to the side wall of the radiating head 5, and the other end of the torsion spring 502 is fixed to the moving frame 4. The torsion spring 502 provides the radiating head 5 with the elastic force for resetting.
[0047] One end of the movable frame 4 is fixedly connected to a top rod 9 for pressing down the radiating head 5.
[0048] The working process of this embodiment is as follows: When the rolling element 6 rotates to the inner ring groove 701, the radiation head 5 is not pressed by the top rod 9 and is in a vertically downward state under the action of the torsion spring 502, which facilitates concentrated vertical irradiation of a specific area.
[0049] When the rolling element 6 rolls from the connecting groove 703 to the outer ring groove 702, the moving frame 4 drives the radiation head 5 to move, so that the radiation head 5 contacts the top rod 9. The top rod 9 presses against the radiation head 5, causing the radiation head 5 to rotate against the elastic force of the torsion spring 502, thereby adjusting the irradiation angle to adapt to the treatment needs of different positions during large-area irradiation.
[0050] Example 3 Based on the above embodiments, this embodiment mainly solves the power supply problem during the rotation of the radiating head 5, and the specific structure is as follows: A support frame 302 is fixed in the middle of the support beam 3, and a rotating block 303 is fixed on the support frame 302. The rotating block 303 is rotatably connected to the center of the fixed plate 7 and rotates together with the support beam 3.
[0051] A power connection post 13 is fixed at the center of the rotating block 303. A spiral wire 14 is connected between the power connection post 13 and the radiating head 5. The spiral wire 14 can extend, retract and twist as the radiating head 5 moves and rotates to ensure the stability of the power supply.
[0052] A power transmission column 15 is fixed inside the outer casing 1 and above the fixed plate 7. An external wire 16 is connected above the power transmission column 15 and is used to connect to an external power source.
[0053] The power receiving post 13 has a slot 1301 inside, and a plug 1501 is fixed to the lower end of the power transmission post 15, which is inserted into the slot 1301. Multiple first conductive rings 1302 are fixed inside the slot 1301, and multiple second conductive rings 1502 are fixed to the outer wall of the plug 1501. When the plug 1501 is inserted into the slot 1301, the multiple first conductive rings 1302 and the multiple second conductive rings 1502 make contact one-to-one, thus realizing the transmission of current.
[0054] In this embodiment, when the radiation head 5 rotates, it rotates within the slot 1301 via the plug 1501. The first conductive ring 1302 and the second conductive ring 1502 remain in contact, ensuring that the radiation head 5 can be stably electrically connected to the external device and guaranteeing the continuous progress of the treatment process.
[0055] Finally, it should be noted that the above embodiments are only used to illustrate and not limit the technical solutions of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the present invention without departing from the spirit and scope of the present invention. Any modifications or partial substitutions should be covered within the scope of the claims of the present invention.
Claims
1. A millimeter-wave therapy device irradiation head structure, characterized in that, include: Outer shell (1); Rotating ring (2), which is rotatably connected to the inside of the outer shell (1); A support beam (3) is laterally fixed on a rotating ring (2); The movable frame (4) is slidably connected to the support beam (3) along the length direction of the support beam (3); Radiation head (5), the radiation head (5) is mounted on the movable frame (4); Among them, the movable frame (4) is provided with a rolling element (6) by a first spring (8), and a fixed plate (7) is provided inside the outer shell (1). The lower surface of the fixed plate (7) is provided with an inner ring groove (701) and an outer ring groove (702). A connecting groove (703) is provided between the inner ring groove (701) and the outer ring groove (702). The rolling element (6) is rolled in the inner ring groove (701) or the outer ring groove (702). A step (704) is provided at the bottom of the inner ring groove (701) and the connection position of the connecting groove (703). A rotating plate (705) is rotatably provided at the connection position of the outer ring groove (702) and the connecting groove (703) to separate the outer ring groove (702) and the connecting groove (703).
2. The structure of the millimeter-wave therapy head according to claim 1, characterized in that, A swing rod (706) is fixed on the rotating shaft of the rotating plate (705). A first connecting column (707) is fixed at the end of the swing rod (706) away from the rotating plate (705). A second connecting column (708) is fixed on the side wall of the fixed plate (7). A tension spring (709) is provided between the first connecting column (707) and the second connecting column (708). Under the tension of the tension spring (709), the swing rod (706) drives the rotating plate (705) to be placed horizontally in the outer ring groove (702), and the outer ring groove (702) and the connecting groove (703) are in a connected state.
3. The structure of the millimeter-wave therapy head according to claim 1, characterized in that, Rotating shafts (501) are fixed on both sides of the radiating head (5), and the radiating head (5) is rotatably connected to the moving frame (4) through the two rotating shafts (501). A torsion spring (502) is sleeved on the rotating shaft (501). One end of the torsion spring (502) is fixed to the side wall of the radiating head (5), and the other end of the torsion spring (502) is fixed to the moving frame (4). One end of the movable frame (4) is fixedly connected to a top rod (9) for pressing down the radiating head (5). When the rolling element (6) rotates to the inner ring groove (701), the radiating head (5) is in a vertically downward state; When the rolling element (6) rolls from the connecting groove (703) to the outer ring groove (702), the radiating head (5) is pressed by the push rod (9), causing the radiating head (5) to rotate against the torsion spring (502).
4. The structure of the millimeter-wave therapy head according to claim 1, characterized in that, A support frame (302) is fixed in the middle of the support beam (3), and a rotating block (303) is fixed on the support frame (302). The rotating block (303) is rotatably connected to the center of the fixed plate (7). A power connection post (13) is fixed in the center of the rotating block (303), and a spiral wire (14) is connected between the power connection post (13) and the radiating head (5). A power transmission column (15) is fixed inside the outer casing (1) and above the fixed plate (7), and an external conductor (16) is connected above the power transmission column (15). The power receiving post (13) has a slot (1301) inside, and a plug (1501) is fixed at the lower end of the power transmission post (15). The plug (1501) is inserted into the slot (1301), and multiple first conductive rings (1302) are fixed inside the slot (1301). Multiple second conductive rings (1502) are fixed on the outer wall of the plug (1501). When the plug (1501) is inserted into the slot (1301), the multiple first conductive rings (1302) and the multiple second conductive rings (1502) make contact one by one.
5. The structure of a millimeter-wave therapy head according to claim 1, characterized in that, The upper and lower surfaces of the supporting beam (3) are provided with tracks (301), and multiple rollers (401) are provided on the moving frame (4) above and below the supporting beam (3). The rollers (401) are tumbling connected in the corresponding tracks (301).
6. The structure of a millimeter-wave therapy head according to claim 1, characterized in that, The bottom of the outer casing (1) is provided with a protective cover (12).
7. The structure of a millimeter-wave therapy head according to claim 1, characterized in that, A motor (201) is fixed on the outer casing (1), and a gear (202) is fixed on the output shaft of the motor (201). The gear (202) meshes with the inner wall of the rotating ring (2). When the motor (201) starts, the output shaft of the motor (201) rotates with the gear (202), and the gear (202) rotates with the rotating ring (2) inside the outer casing (1).
8. The structure of a millimeter-wave therapy head according to claim 1, characterized in that, The outer shell (1) includes an upper shell (101) and a lower shell (102), which are fixedly connected by bolts.
9. The structure of a millimeter-wave therapy head according to claim 8, characterized in that, A connecting frame (103) is provided at the connection between the upper shell (101) and the lower shell (102).
10. The structure of a millimeter-wave therapy head according to claim 8, characterized in that, Positioning plates (10) are fixed on both sides of the fixed plate (7), and positioning grooves (11) are opened on both sides of the inner wall of the lower shell (102). When the fixed plate (7) is installed into the outer casing (1), the positioning plate (10) is inserted into the positioning groove (11) to fix the fixed plate (7).