Light measuring device

Abstract

The invention relates to in-vitro detection equipment, in particular to a photometric device which comprises a reaction cup, a transfer module used for driving the reaction cup to move and a photometric module, the transfer module comprises a transfer guide groove, a pushing handle is arranged above the transfer guide groove, a through hole corresponding to the photometric module in position is formed in the transfer guide groove, and the photometric module is arranged in the through hole. The light metering module comprises a shielding base located below the transfer guide groove, a light metering cavity located below the through hole is formed in the shielding base, a cup holder is arranged in the light metering cavity, and a lifting mechanism used for driving the cup holder to move longitudinally is arranged on the shielding base. The longitudinal height of the photometric equipment can be further compressed, and the effect of compressing the size of the equipment is achieved.

Description

Technical Field

[0001] The present invention relates to the field of in vitro diagnostic equipment, and in particular to a photometric device. Background Art

[0002] Chemiluminescence detection technology is a highly sensitive and specific analytical technology that has developed rapidly in the world in recent years. Chemiluminescence immunoassay analyzers designed using chemiluminescence detection technology are used in clinical laboratories to detect various indicators of blood, urine or other body fluids. The principle is to combine antibody-antigen reaction with chemiluminescence to achieve high specificity and high sensitivity. As the direct data of the concentration of the substance to be detected, the accuracy and reliability of the photometric device are very important.

[0003] With the development of medical testing technology in recent years, there are more and more various instruments in the laboratory; at the same time, with the popularization of people's medical diagnosis concepts, the number of samples that need to be tested has also increased year by year. Therefore, existing testing instruments are developing in the direction of high throughput and small size, which poses new challenges to medical instrument designers. The existing chemiluminescence immunoassay instrument photometry device is often independent, and requires a gripper to transfer the reaction cup for photometry, which is not conducive to the improvement of the unit area flux, or the longitudinal dimension is too large without a gripper; and the transfer gripper has multiple degrees of freedom or requires a longitudinal switching structure, which is complex and costly, and the high failure rate is not conducive to achieving the purpose of accurate inspection. During photometry, due to the limited detection range of the photometric component, when the luminescence value exceeds its photometric range, a filter needs to be involved, the luminescence value is attenuated and then detected by the photometric equipment, and then the luminescence value of the object to be measured is converted through the relevant conversion, thereby converting the concentration.

[0004] For example, the Chinese patent (application number: 2023117180778) discloses a photometric device and a sample analyzer, wherein the photometric device includes a base, a photometric component, a mixing component and a driving component, and the driving component is connected to the carrier to drive the carrier to perform a mixing operation, so that the sample in the reaction cup placed in the reaction cup bearing position can be fully mixed. The driving component can also drive the carrier and the photometric component to move relative to each other, so that the reaction cup bearing position is opposite to the photometric component, so that the sample in the reaction cup placed in the reaction cup bearing position can be opposite to the photometric component, and the photometric component can perform photometric detection on the mixed sample. In this way, there is no need to separately set up a mechanism for mixing the carrier and a mechanism for driving the reaction cup bearing position to be opposite to the photometric component, thereby reducing the number of components of the photometric device of the present application, making the structure of the photometric device more compact. Although the device can reduce the volume of the overall photometric device, it still has problems such as excessive longitudinal size, multiple drives, and high failure rate. Summary of the invention

[0005] In order to solve the above problems, an embodiment of the present invention provides a light measuring device, which has the advantages of small size, convenient operation and good operation stability.

[0006] In order to achieve the above-mentioned purpose, the embodiment of the present invention specifically adopts the following technical scheme: a photometric device, comprising a reaction cup, a transfer module for driving the reaction cup to move, and a photometric module, the transfer module comprising a transfer guide groove, a pusher is arranged above the transfer guide groove, a through hole corresponding to the position of the photometric module is arranged on the transfer guide groove, the photometric module comprises a shielding base located below the transfer guide groove, a photometric chamber located below the through hole is arranged on the shielding base, a cup holder is arranged in the photometric chamber, a lifting mechanism for driving the cup holder to move longitudinally is arranged on the shielding base, a photometric element is arranged on one side of the photometric chamber, and a driving device connected to the lifting mechanism is arranged below the photometric element.

[0007] As a further improvement of the above technical solution:

[0008] The driving device comprises a motor base, a driving motor is arranged on the motor base, a driving disk located between the photometric element and the shielding base is arranged at the output end of the driving motor, and a track groove and a light-transmitting module are arranged on the driving disk.

[0009] The light-transmitting module comprises a light-transmitting hole 1 and a light-transmitting hole 2, and a filter is arranged on the light-transmitting hole 1.

[0010] The lifting mechanism comprises a horizontally distributed guide rail 1 and a longitudinally distributed guide rail 2, the guide rail 1 is provided with a light-shielding door component, the guide rail 2 is provided with a hand clamping component, and the hand clamping component is provided with a cam bearing used in conjunction with a track groove.

[0011] The light-shielding door component comprises two light-shielding plates which are symmetrically distributed with the center line of the guide rail 1 as the axis. Both light-shielding plates are slidably connected to the guide rail 1, and guide grooves are arranged on the side walls of the light-shielding plates.

[0012] A sealing assembly is arranged on the upper part of the light-shielding door component, and the sealing assembly comprises a sealing door edge 1 and a sealing door edge 2. The sealing door edge 1 and the sealing door edge 2 are respectively located on the upper parts of two shading plates and move with the shading plates.

[0013] The gripping component comprises a gripping base, on which gripping hands 1 and 2 are arranged. The lower parts of gripping hands 1 and 2 are slidably connected to the gripping base, and the upper parts are both provided with gripping fingers located on both sides of the cup holder.

[0014] A storage groove for installing a cup holder is arranged in the middle of the grip base, a floating compression spring is arranged between the lower part of the cup holder and the bottom of the storage groove, and a sliding block connected to the second guide rail is arranged on the side wall of the cup holder.

[0015] A gripper guide rail is arranged in the middle of the gripper base, and two sliding seats for mounting gripper one and gripper two respectively are arranged on the gripper guide rail, and a gripper tension spring is arranged between the two sliding seats.

[0016] A limit clamping plate is arranged in the middle of the first and second clamping hands, and tightening protrusions used in conjunction with the limit clamping plate are arranged on the two shading plates, and the tightening protrusions are located on the inner side of the limit clamping plate.

[0017] The beneficial effects of the embodiments of the present invention are as follows: 1. The photometric device comprises a reaction cup, a transfer module for driving the reaction cup to move, and a photometric module, wherein the transfer module comprises a transfer guide groove, a pusher is arranged above the transfer guide groove, a through hole corresponding to the position of the photometric module is arranged on the transfer guide groove, the photometric module comprises a shielding base located below the transfer guide groove, a photometric chamber located below the through hole is arranged on the shielding base, a cup holder is arranged in the photometric chamber, and a lifting mechanism for driving the cup holder to move longitudinally is arranged on the shielding base, and the longitudinal height of the photometric device can be further compressed by the lower photometric chamber and the photometric mechanism, thereby achieving the effect of compressing the volume of the device.

[0018] 2. The design of the clamping part can clamp and limit the reaction cup to prevent the reaction cup from shaking when rising or falling.

[0019] 3. The opening and closing of the light-shielding door component can provide light-proof seals on both sides of the light-measuring chamber. The first sealing door edge is inserted into the second sealing door edge to achieve sealing of the upper part of the light-measuring chamber. Compared with the existing method of sealing the upper part of the light-measuring chamber by other mechanisms during the light-measuring operation, the sealing method provided by the present invention does not require the use of an additional top sealing mechanism, and is synchronously driven by the same driving source as the cup holder. While sealing the top of the light-measuring chamber, it can also further reduce the volume of the entire device and save equipment costs.

[0020] 4. The light-proof door component, the hand clamp component, and the cup holder share a driving device, which saves equipment costs, simplifies equipment components, and facilitates later use and equipment maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0022] Figure 2 It is a schematic diagram of the installation structure of the shielding base in the present invention;

[0023] Figure 3 for Figure 2 A schematic diagram of the enlarged structure at A in the middle;

[0024] Figure 4 It is a structural schematic diagram of the light-shielding door component in the present invention;

[0025] Figure 5 It is a schematic diagram of the state change of the hand clamping base in the present invention;

[0026] Figure 6 It is a structural schematic diagram of the track groove in the present invention;

[0027] Figure 7 It is a schematic diagram of the motion state of the sunshade in the present invention.

[0028] In the figure: 1, reaction cup; 2, transfer guide groove; 3, push handle; 4, through hole; 5, shielding base; 6, light measuring chamber; 7, cup holder; 8, light measuring element; 9, motor base; 10, drive motor; 11, drive disk; 12, track groove; 13, light transmission hole 1; 14, light transmission hole 2; 15, filter; 16, guide rail 1; 17, guide rail 2; 18, cam bearing; 19, light shielding plate; 20, guide groove Road; 21. Sealing door edge one; 22. Sealing door edge two; 23. Clamp base; 24. Clamp one; 25. Clamp two; 26. Clamping finger; 27. Storage slot; 28. Floating compression spring; 29. ​​Sliding seat; 30. Clamp tension spring; 31. Limiting card plate; 32. Tightening protrusion; 33. Clamp guide rail; 34. Operating area one; 35. Operating area two; 36. Operating area three; 37. Shade plate bearing. DETAILED DESCRIPTION

[0029] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0030] like Figure 1 As shown, the photometric device of this embodiment includes a reaction cup 1 for containing a liquid to be detected, a transfer module for driving the reaction cup 1 to move, and a photometric module. The transfer module includes a transfer guide groove 2, a pusher 3 is provided above the transfer guide groove 2, and a through hole 4 corresponding to the position of the photometric module is provided on the transfer guide groove 2. During the operation of the pusher 3, the upper half of the cup holder 7 is located in the through hole 4 and the upper surface of the cup holder 7 is substantially flush with the bottom of the transfer groove on the guide groove 2. The through hole 4 is located above the photometric module. The transfer module drives the reaction cup to move along the transfer guide groove 2, and when it moves to the through hole 4, it is transferred by the clamping hand and the cup holder to the photometric module for photometry. The transfer module uses an annular or linear transfer channel to drive the movement of the reaction cup 1.

[0031] The photometric module includes a shielding base 5 located below the transfer guide groove 2, a photometric chamber 6 located below the through hole 4 is provided on the shielding base 5, a cup holder 7 is provided in the photometric chamber 6 for receiving the reaction cup 1 and driving the reaction cup 1 into the photometric chamber 6, a lifting mechanism for driving the cup holder 7 to move longitudinally is provided on the shielding base 5, a photometric element 8 is provided on one side of the photometric chamber 6, a driving device connected to the lifting mechanism is provided below the photometric element 8, and the driving device is used to drive the cup holder 7 to move up and down, so as to drive the reaction cup 1 to enter or leave the photometric chamber 6.

[0032] The driving device includes a motor base 9, on which a driving motor 10 is provided, and an output end of the driving motor 10 is installed with a driving disk 11 located between the photometric element 8 and the shielding base 5, and a track groove 12 and a light-transmitting module are provided on the driving disk 11, the track groove 12 is divided into two sections and is symmetrically distributed, and each track groove 12 includes an operating area 1 34, an operating area 2 35 and an operating area 36, ​​the diameter of the operating area 1 34 is greater than the diameter of the operating area 2 35, and the operating area 36 is located between the operating area 1 34 and the operating area 2 35 and the diameter gradually increases. During operation, when the cam bearing 18 moves from the operating area 2 35 to the operating area 1 34 in the track groove 12, the cup holder 7 moves upward, and when the cup holder 7 moves to the highest position, it enters the next track groove 12 and moves from the operating area 1 34 to the operating area 2 35, and at this time the cup holder 7 moves downward.

[0033] It should be noted that the two track grooves 12 are symmetrically designed and are actually composed of a complete cam. They are divided into two descriptions here to distinguish the movement trajectory of the cam bearing 18 when the gripper base rises and falls.

[0034] The light transmission module includes a light transmission hole 13 and a light transmission hole 14. A filter 15 is provided on the light transmission hole 13. The design of the two light transmission holes allows selection of the filter 15 according to whether the filter 15 is needed for operation requirements.

[0035] The lifting mechanism includes a transversely distributed guide rail 16 and a longitudinally distributed guide rail 2 17. The guide rail 16 is provided with a light-proof door component for closing the light measuring chamber 6 during detection. The guide rail 2 17 is provided with a hand clamping component, which can clamp the reaction cup 1 to prevent the reaction cup 1 from shaking during the falling process. The middle part of the hand clamping component is provided with a cam bearing 18 used in conjunction with the track groove 12. The cup holder 7 is slidably mounted on the guide rail 2 17, and the cam bearing 18 is located in the track groove 12. The driving motor 10 is used to drive the driving disk 11 to rotate, and the cam bearing 18 moves in the track groove 12, thereby driving the cup holder 7 to complete the longitudinal movement.

[0036] The light-shielding door component includes two light-shielding plates 19 which are symmetrically distributed with the center line of the guide rail 16 as the axis. The two light-shielding plates 19 are both slidably connected to the guide rail 16. A guide groove 20 is provided on the side wall of the light-shielding plate 19. The clamping base 23 is provided with a light-shielding plate bearing 37 corresponding to the position of the guide groove 20. As the clamping base 23 rises and falls, the light-shielding plate bearing 37 moves in the guide groove 20, thereby driving the two light-shielding plates 19 to close or open.

[0037] A sealing assembly is provided on the upper part of the light-shielding door component, and the sealing assembly includes a sealing door edge 1 21 and a sealing door edge 22. The sealing door edge 1 21 and the sealing door edge 22 are respectively located on the upper parts of the two shading plates 19 and move with the shading plates 19. When performing light measuring operations, the two shading plates 19 move toward the middle. After the two shading plates 19 are closed, the sealing door edge 1 21 and the sealing door edge 22 are pressed together, or the ends are staggered and abutted to achieve sealing of the upper part of the light measuring chamber 6. Compared with the existing method of using other mechanisms to seal the upper part of the light measuring chamber 6 during the light measuring operation, the sealing method provided by the present invention does not require the use of an additional top sealing mechanism, and is synchronously driven with the cup holder 7 using the same driving source. While sealing the top of the light measuring chamber 6, it can further reduce the volume of the entire device and save equipment costs.

[0038] The gripper component includes a gripper base 23, on which gripper one 24 and gripper two 25 are provided, the lower parts of gripper one 24 and gripper two 25 are slidably connected to the gripper base 23, the middle part of the gripper base 23 is provided with a gripper guide rail 33, on which two sliding seats 29 are provided respectively for mounting gripper one 24 and gripper two 25, a gripper tension spring 30 is provided between the two sliding seats 29, the upper parts of gripper one 24 and gripper two 25 are provided with gripper fingers 26 located on both sides of the cup holder 7, the gripper fingers 26 grip the reaction cup 1 when the cup holder 7 is descending, to prevent the reaction cup 1 from being deflected or sliding, and to enhance the stability of the reaction cup 1 during the descending process.

[0039] A storage groove 27 for mounting the cup holder 7 is provided in the middle of the gripper base 23, a floating compression spring 28 is provided between the lower part of the cup holder 7 and the bottom of the storage groove 27, a sliding block connected to the guide rail 2 17 is provided on the side wall of the cup holder 7, and the floating compression spring 28 plays a role in compressing the distance when the cup holder 7 reaches the highest position and the gripper base 23 continues to rise, so as to ensure that the sealing door edge 1 21 and the sealing door edge 22 can open the gripper when they are closed, and ensure that the cup holder 7 drags the reaction cup in the theoretical position without moving.

[0040] A limit card plate 31 is provided in the middle of the clamping hand 1 24 and the clamping hand 25, and a tightening protrusion 32 used in conjunction with the limit card plate 31 is provided on the two shading plates 19, and the tightening protrusion 32 is located on the inner side of the limit card plate 31. During the rising process of the light-shielding door component, when the two shading plates 19 expand outward, the tightening protrusion 32 will push the limit card plate 31 outward. At this time, the clamping hand spring 30 expands under the action of the thrust, and the distance between the clamping hand 1 24 and the clamping hand 25 increases, so that the reaction cup 1 is not clamped by the clamping hand, so that the pusher 3 can push the reaction cup to the next station.

[0041] Instructions for use: The push handle 3 drives the reaction cup 1 to move on the transfer guide groove 2. When it moves to the through hole 4, the upper end of the cup holder 7 is located at the top of the through hole 4 (i.e., the bottom of the transfer guide groove), and the reaction cup 1 falls on the cup holder 7. At this time, the clamping hand 1 24 and the clamping hand 2 25 are opened by the action of the limit card plate 31 and the tightening protrusion 32. The clamping hand spring is in the open state, and the reaction cup 1 enters between the clamping hand 1 24 and the clamping hand 25. The bottom of the reaction cup is dragged by the cup holder 7, and the driving motor 10 is started, driving the driving disk 11 to start rotating. At this time, the cam bearing 18 is driven in the track groove 12 to move downward along the guide rail 2 18, and then drives the clamping hand base 23 to start moving. During the movement, the light-shielding door component and the clamping hand component are Figure 5The state 1 in the figure changes to the state 2. As the gripper base 20 moves downward, the limit clamping plate 31 and the tightening protrusion 32 are separated, and the gripper spring 30 is reset and retracted inward, driving the gripper 1 24 and the gripper 25 to move inward, and the clamping finger 26 clamps the reaction cup 1 to ensure the stability of the reaction cup 1 during the sinking process. At the same time, the floating spring 28 under the cup holder 7 gradually returns to its original state. Then, as the gripper base 23 descends, during the continuous descent of the gripper base 23, the visor bearing 37 installed on the gripper base 23 moves from top to bottom in the guide groove 20. The two shading plates 19 are moved together during the movement to seal the two sides of the light measuring chamber 6. When the gripping base 23 is lowered to the lowest point, the two shading plates 19 are closed to drive the sealing door edge 1 21 and the sealing door edge 22 to close, thereby sealing the top of the light measuring chamber 6. The device transfers the reaction cup 1 to the light measuring chamber 6 by moving the gripping base 23. At the same time, the light shielding door component and the sealing component can be used to seal the four sides of the light measuring chamber 6 to form a light measuring chamber 6 with good light shielding effect, thereby ensuring the accuracy of the light measuring operation. After the operation is completed, the driving motor 10 continues to rotate, and the cam bearing 18 moves to the next track groove 12. At this time, the gripper base 23 starts to move upward. During the upward movement, the shading plate bearing 37 moves in the opposite direction in the guide groove 20, driving the two shading plates 19 to open, ensuring that the reaction cup can smoothly pass through the through hole and the shading plate 19 during the rising process. In the early stage of the rising of the gripper base 23, the gripper 1 24 and the gripper 2 25 are still in a clamping state to ensure the stability of the reaction cup 1 during the rising. As the gripper base 23 rises, the upper end of the cup holder 7 reaches the through hole. When the cup holder 7 reaches the top of the hole 4 (i.e., the bottom of the transfer guide groove), the cup holder 7 no longer rises, and the gripper base 23 continues to rise. After compressing the floating compression spring 28, it continues to rise by utilizing the avoidance provided by the floating compression spring. During this rising process, the limit card plate 31 contacts the tightening protrusion 32. As the gripper base 23 continues to rise, the shading plate bearing 39 moves to the top in the guide groove, and the two shading plates 19 are fully opened. At this time, the tightening protrusion 32 applies an outward thrust to the limit card plate 31, and the gripper spring 30 is stretched. After the gripper 1 24 and the gripper 2 25 are opened, the clamping restriction on the reaction cup 1 is cancelled.

[0042] It should be noted that in the description of the present invention, the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, which are only for the convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0043] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] The term "comprise" or any other similar term is intended to cover a non-exclusive inclusion, such that a process, article, or apparatus / device that includes a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, article, or apparatus / device.

[0045] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A photometric device, comprising a reaction cup (1), a transport module for driving the reaction cup (1) to move, and a photometric module, characterized in that: The transfer module comprises a transfer guide groove (2), a push handle (3) is arranged above the transfer guide groove (2), and a through hole (4) corresponding to the position of the light measuring module is arranged on the transfer guide groove (2); The photometric module comprises a shielding base (5) located below the transfer guide groove (2); a photometric chamber (6) located below the through hole (4) is arranged on the shielding base (5); a cup holder (7) is arranged in the photometric chamber (6); a lifting mechanism for driving the cup holder (7) to move longitudinally is arranged on the shielding base (5); a photometric element (8) is arranged on one side of the photometric chamber (6); and a driving device connected to the lifting mechanism is arranged below the photometric element (8).

2. The light measuring device according to claim 1, characterized in that: The driving device comprises a motor base (9), a driving motor (10) is arranged on the motor base (9), a driving disk (11) located between a photometric element (8) and a shielding base (5) is arranged at the output end of the driving motor (10), and a track groove (12) and a light-transmitting module are arranged on the driving disk (11).

3. The light measuring device according to claim 2, characterized in that: The light-transmitting module comprises a light-transmitting hole 1 (13) and a light-transmitting hole 2 (14), and a filter (15) is arranged on the light-transmitting hole 1 (13).

4. The light measuring device according to claim 2, characterized in that: The lifting mechanism comprises a transversely distributed guide rail 1 (16) and a longitudinally distributed guide rail 2 (17); the guide rail 1 (16) is provided with a light-shielding door component; the guide rail 2 (17) is provided with a hand-clamping component; and the hand-clamping component is provided with a cam bearing (18) used in conjunction with the track groove (12).

5. The light measuring device according to claim 4, characterized in that: The light-shielding door component comprises two light shielding plates (19) symmetrically distributed with the center line of the guide rail (16) as the axis, the two light shielding plates (19) are both slidably connected to the guide rail (16), and the side walls of the light shielding plates (19) are provided with guide grooves (20).

6. The light measuring device according to claim 5, characterized in that: A sealing assembly is provided on the upper part of the light-shielding door component, and the sealing assembly comprises a sealing door edge 1 (21) and a sealing door edge 2 (22). The sealing door edge 1 (21) and the sealing door edge 2 (22) are respectively located on the upper parts of the two light shielding plates (19) and move along with the light shielding plates (19).

7. The light measuring device according to claim 6, characterized in that: The gripping component comprises a gripping base (23), on which a gripping hand (24) and a gripping hand (25) are arranged. The lower parts of the gripping hand (24) and the gripping hand (25) are slidably connected to the gripping base (23), and the upper parts of the gripping hand (24) and the gripping hand (25) are both provided with gripping fingers (26) located on both sides of the cup holder (7).

8. The light measuring device according to claim 7, characterized in that: A storage groove (27) for mounting a cup holder (7) is provided in the middle of the grip base (23), a floating compression spring (28) is provided between the lower part of the cup holder (7) and the bottom of the storage groove (27), and a sliding block connected to the second guide rail (17) is provided on the side wall of the cup holder (7).

9. The light measuring device according to claim 7, characterized in that: A gripper guide rail (33) is arranged in the middle of the gripper base (23), and two sliding seats (29) are arranged on the gripper guide rail (33) for mounting gripper one (24) and gripper two (25) respectively, and a gripper tension spring (30) is arranged between the two sliding seats (29).

10. The light measuring device according to claim 9, characterized in that: A limit clamping plate (31) is arranged in the middle of the first clamping hand (24) and the second clamping hand (25), and a tightening protrusion (32) used in conjunction with the limit clamping plate (31) is arranged on the two shading plates (19), and the tightening protrusion (32) is located on the inner side of the limit clamping plate (31).

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