Outdoor safety type intelligent electric energy metering box

By using a limit locking structure, a rotating structure, and an elastic sliding mechanism, combined with ventilation and moisture absorption components, the safety reset problem when the air switch trips and the heat dissipation problem in high temperature and rainy weather are solved, thus achieving the safety and stability of the outdoor intelligent power metering box.

CN122051802APending Publication Date: 2026-05-15MINGQI ELECTRIC CO LTD
View PDF 3 Cites 0 Cited by

Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
MINGQI ELECTRIC CO LTD
Filing Date
2026-03-10
Publication Date
2026-05-15

AI Technical Summary

Technical Problem

Existing outdoor smart electricity metering boxes are inconvenient to restore power in time when the circuit breaker trips due to excessive current, the observation window is prone to accidental operation and may cause danger, and they are prone to overheating in hot and rainy weather, which affects heat dissipation.

Method used

The design incorporates a limiting engagement structure, a rotating structure, an elastic sliding mechanism, and a crank-connecting rod mechanism, combined with ventilation and moisture absorption components, to achieve intelligent control of the air switch, a safety observation window, and effective heat dissipation.

Benefits of technology

The safety reset capability of the air switch has been improved to prevent misoperation, ensure ventilation and heat dissipation in rainy weather, avoid internal water mist short circuits and high temperature damage, and enhance the safety and stability of outdoor use.

✦ Generated by Eureka AI based on patent content.

Smart Images

  • Figure CN122051802A_ABST
    Figure CN122051802A_ABST
Patent Text Reader

Abstract

The invention, which belongs to the technical field of the intelligent electric energy metering box, discloses an outdoor safe intelligent electric energy metering box comprising a metering box body and an electric energy meter assembled by the metering box body. Comprising a supporting rod, the supporting rod is installed on the inner surface of the metering box body, an air switch is installed on the outer surface of the supporting rod in a clamped mode, a cabinet door is rotationally connected to the outer surface of the metering box body, an observation window is connected to the inner surface of the cabinet door in a nested mode, an identity recognizer is installed on the inner surface of the cabinet door, and an inspection window is rotationally connected to the inner surface of the cabinet door. According to the outdoor safety type intelligent electric energy metering box, the metering box body is arranged, the electric energy meter and the air switch are protected through the cabinet door, and through the inspection window which can be intelligently opened and closed, when the air switch cannot be reset, the air switch can be conveniently controlled to be reset through a professional, and the ventilation assembly is matched for use, so that the safety of the electric energy metering box is greatly improved in outdoor rainy weather. The safety of internal ventilation is improved, and short circuit caused by internal water mist is avoided.
Need to check novelty before this filing date? Find Prior Art

Description

Technical Field

[0001] This invention relates to the field of intelligent energy metering box technology, specifically an outdoor safety intelligent energy metering box. Background Technology

[0002] A smart electricity metering box is a device in which an electricity meter and a box are assembled together. It can effectively protect the electricity meter and prevent unauthorized personnel from touching it. With the addition of an observation window, it is easy to check the electricity data in a timely manner and reduce the opening and closing of the box, thus improving work safety. However, during use, it is not convenient to implement stable safety protection and is prone to accidental activation and danger.

[0003] To overcome the aforementioned shortcomings, existing technology (Chinese patent application CN202122041633.5, filed August 27, 2021) provides an intelligent electricity metering box. This box uses a first voltage sensor and a second voltage sensor to monitor the power supply line and the internal equipment's power transmission. In case of a fault, the fault information can be quickly fed back to a remote control terminal, allowing users and operators to obtain fault information promptly and quickly determine the cause of the power outage, facilitating rapid repair. Another existing technology (Chinese patent application CN202311565829.1, filed November 22, 2023) provides an intelligent electricity metering box. Its locking mechanism, by engaging with a locking groove on the inner wall of the box, ensures the box's anti-theft performance without requiring additional actions; simply closing the door allows for rapid sealing of the box, improving its practicality and convenience. The present invention relates to a smart electricity metering box, and to prior art (Chinese patent application CN202311125379.4, filed on 2023-09-01). The present invention describes a smart electricity metering box in which the operator rotates the door handle, causing a movable block to move. This movement separates the connecting block from the first and second metal blocks. The operator then opens the door, which, via a rotating rod, moves a fixed block. This movement causes a locking rod to slide within a locking slot. The locking rod, under the action of an inclined plane, inserts into a locking groove, thus locking the movable block. The locking rod, through a locking disc, compresses the locking spring, preventing the movable block from resetting. While the prior art provides safety protection, it is inconvenient to promptly restore power when the circuit breaker trips due to excessive current. Furthermore, the self-opening observation window poses a risk of danger during operation. Outdoor electricity metering boxes are also prone to overheating in hot and rainy weather, affecting normal heat dissipation.

[0004] To address the aforementioned issues, there is an urgent need for innovative designs based on existing outdoor safety-type intelligent electricity metering boxes. Summary of the Invention

[0005] The purpose of this invention is to provide an outdoor safety-type intelligent electricity metering box to solve the problems mentioned in the background art, such as the inconvenience of timely power restoration when the air switch trips due to excessive current, the danger of the self-opening observation window during operation, and the fact that outdoor electricity metering boxes are prone to internal overheating and affecting normal heat dissipation in hot and rainy weather.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an outdoor safety-type intelligent electricity metering box, comprising a metering box body and an electricity metering device assembled thereon; including: a support rod installed on the inner surface of the metering box body, with an air switch engaged on the outer surface of the support rod, and a cabinet door rotatably connected to the outer surface of the metering box body, with an observation window nested on the inner surface of the cabinet door, an identification device installed on the inner surface of the cabinet door, and an inspection window rotatably connected to the inner surface of the cabinet door, with a locking assembly installed on the inner wall of the cabinet door, and the locking assembly connected to a locking buckle via a meshing limiting mechanism, and the inspection window connected to a top plate via an elastic sliding mechanism, and a ventilation assembly installed on the lower surface of the metering box body, and the ventilation assembly connected to a moisture-absorbing assembly via a crank-connecting rod mechanism.

[0007] Preferably, the metering box is connected to the air switch via a support rod to form a limiting engagement structure, and the metering box and the cabinet door form a rotating structure. The cabinet door, the observation window, and the identification device form an embedded structure, and the cabinet door and the inspection window form a rotating structure.

[0008] Preferably, the engagement limiting mechanism further includes a gear rotatably connected to the inner surface of the locking assembly, and a rack meshing with the outer surface of the gear, which limits the rack to slide on the inner surface of the locking assembly. A moving rod is installed on the outer surface of the rack, and a positioning pin is installed on the outer surface of the moving rod. A locking buckle is engaged with the outer surface of the positioning pin, and the locking buckle is installed on the outer surface of the inspection window.

[0009] Preferably, the locking assembly and the cabinet door form an integrated structure, and the locking assembly forms a meshing structure through gears and racks, and the rack and the moving rod form an integrated structure. At the same time, the moving rod forms a limiting engagement structure through a positioning pin and a locking buckle, and the locking buckle and the inspection window form an integrated structure.

[0010] Preferably, the elastic sliding mechanism further includes a movable plate slidably connected to the inner surface of the inspection window, and a lifting plate is installed on the outer surface of the movable plate. A compression spring is elastically connected between the lifting plate and the inspection window. Meanwhile, a top plate is rotatably connected to the outer surface of the lifting plate, and a tension spring is elastically connected between the top plate and the lower side of the lifting plate. A switch button is connected to the upper side of the outer surface of the top plate, and the switch button is rotatably connected to the outer end of the air switch.

[0011] Preferably, the inspection window is formed by a compression spring and a movable plate to form an elastic lifting structure, and the movable plate and the lifting plate form an integrated structure. The lifting plate and the inspection window form an embedded sealing structure, and the lifting plate and the top plate form a rotating structure.

[0012] Preferably, the top plate forms an elastic rotating structure with the lifting plate via a tension spring, and the top plate forms a compression structure with the switch button.

[0013] Preferably, the crank-connecting rod mechanism further includes a turntable rotatably connected to the inner surface of the ventilation assembly, and a connecting rod rotatably connected to the outer surface of the turntable, and an offset rod rotatably connected to the other end of the outer surface of the connecting rod, while a moisture-absorbing assembly is installed on the outer surface of the offset rod.

[0014] Preferably, the ventilation component and the turntable form a rotating structure, and the turntable forms a crank-connecting rod structure with the offset rod through the connecting rod, and the offset rod and the moisture absorption component form an integrated structure, while the moisture absorption component and the ventilation component form a telescopic structure.

[0015] Preferably, the inner surface of the moisture-absorbing component is nested with moisture-absorbing material, and the upper surface of the ventilation component is equipped with an intake fan. The lower side of the outer surface of the ventilation component is provided with an air inlet, and the outer surface of the metering box is provided with an air outlet. The moisture-absorbing component and the moisture-absorbing material form an embedded structure, and the moisture-absorbing material, the intake fan, and the air inlet are arranged on the same central axis.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. This outdoor safety-type intelligent electricity metering box is equipped with a metering enclosure. The electricity meter and circuit breaker are protected by the cabinet door. The intelligently openable inspection window allows for professional control and reset if the circuit breaker cannot be reset. In addition, the use of ventilation components improves the safety of internal ventilation in rainy weather and avoids short circuits caused by water vapor inside.

[0017] 2. This outdoor safety-type intelligent electricity metering box is equipped with a meshing limit mechanism. An observation window installed on the cabinet door allows for easy viewing of the electricity meter data. The corresponding air switch for the inspection window allows for easy locking and closing of the window via a locking assembly. If the air switch malfunctions, it can be opened and closed for repair by professionals. Furthermore, a flexible sliding mechanism allows for effective control of the lifting plate position via the movable plate assembled with the inspection window. This drives the top plate to lift and rotate the switch button, facilitating reset when the current trips due to excessive current. In case of damage, it can be reset or repaired by professionals, improving safety during use.

[0018] 3. This outdoor safety-type intelligent electricity metering box is equipped with a crank-connecting rod mechanism, which, in conjunction with the turntable installed on the ventilation component, effectively controls the offset rod of the connecting rod assembly to adjust the moisture absorption component. This improves the absorption of moisture during rain, enhances ventilation stability on rainy days, and prevents damage to the inside of the metering box caused by rain. Furthermore, in conjunction with the intake fan installed on the ventilation component, it effectively coordinates the air inlet and outlet to achieve stable cooling. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the three-dimensional structure of the metering box of the present invention; Figure 2 This is a half-section three-dimensional structural diagram of the metering box of the present invention; Figure 3 This is a three-dimensional structural diagram of the inspection window of the present invention; Figure 4 For the present invention Figure 3 Enlarged 3D structural diagram at point A in the middle; Figure 5 This is a schematic diagram of the three-dimensional structure of the top plate of the present invention; Figure 6 For the present invention Figure 5 Enlarged 3D structural diagram at point B; Figure 7 This is a three-dimensional structural diagram of the connecting rod of the present invention; Figure 8 For the present invention Figure 7 A schematic diagram of the three-dimensional structure in partial cross-section.

[0020] In the diagram: 1. Metering box; 2. Energy meter; 3. Support rod; 4. Air switch; 5. Cabinet door; 6. Observation window; 7. Identifier; 8. Inspection window; 9. Locking assembly; 10. Gear; 11. Rack; 12. Moving rod; 13. Positioning pin; 14. Locking buckle; 15. Moving plate; 16. Lifting plate; 17. Compression spring; 18. Top plate; 19. Tension spring; 20. Switch button; 21. Ventilation assembly; 22. Turntable; 23. Connecting rod; 24. Offset rod; 25. Moisture absorption assembly; 26. Moisture absorption material; 27. Inlet fan; 28. Air inlet; 29. ​​Air outlet. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Please see Figures 1-8The present invention provides a technical solution: an outdoor safety intelligent power metering box, which is equipped with a metering box 1 and a power metering device 2 assembled in the metering box 1.

[0023] Example 1: As Figures 1-8 The present invention provides the following technical solution: an outdoor safety-type intelligent electricity metering box, comprising: a support rod 3 installed on the inner surface of the metering box 1, an air switch 4 engaged on the outer surface of the support rod 3, a cabinet door 5 rotatably connected to the outer surface of the metering box 1, an observation window 6 nested on the inner surface of the cabinet door 5, an identification device 7 installed on the inner surface of the cabinet door 5, an inspection window 8 rotatably connected to the inner surface of the cabinet door 5, a locking assembly 9 installed on the inner wall of the cabinet door 5, a locking buckle 14 connected to the locking assembly 9 through a meshing limiting mechanism, a top plate 18 connected to the inspection window 8 through an elastic sliding mechanism, a ventilation assembly 21 installed on the lower surface of the metering box 1, and a moisture-absorbing assembly 25 connected to the ventilation assembly 21 through a crank-connecting rod mechanism.

[0024] When the metering box 1 is in use, an energy meter 2 and a support rod 3 will be installed inside the metering box 1. An air switch 4 will be installed on the support rod 3, and a cabinet door 5 will be rotated and connected to the metering box 1 to effectively protect the energy meter 2 and the air switch 4. The observation window 6 installed on the cabinet door 5 can effectively transcribe the numbers on the energy meter 2. With the intelligent unlocking inspection window 8, if the air switch 4 cannot be reset, it can be reset by a professional. In conjunction with the ventilation component 21 and the moisture absorption component 25 assembled in the metering box 1, safe ventilation is improved during rain.

[0025] Example 2: Figures 1-6 The technical solution shown, based on Embodiment 1, further discloses a reset mechanism for components in the metering box 1 when they trip, and safe maintenance procedures in case of damage. This solves the problems of inconvenience in timely power restoration when the air switch 4 trips due to excessive current, and the potential for danger during operation when an independent, openable observation window 6 is provided at the air switch 4. Specifically, the metering box 1 and the air switch 4 form a limiting engagement structure via the support rod 3, and the metering box 1 and the cabinet door 5 form a rotating structure. The cabinet door 5, the observation window 6, and the identification device 7 form an embedded structure, while the cabinet door 5 and the inspection window 8 also form a rotating structure. Figure 3 and Figure 4As shown, the engagement limiting mechanism also includes a gear 10 rotatably connected to the inner surface of the locking assembly 9, and a rack 11 meshing with the outer surface of the gear 10, limiting the rack 11 to slide on the inner surface of the locking assembly 9. A moving rod 12 is mounted on the outer surface of the rack 11, and a positioning pin 13 is mounted on the outer surface of the moving rod 12. A locking buckle 14 is engaged with the outer surface of the positioning pin 13, and the locking buckle 14 is mounted on the outer surface of the inspection window 8. Figure 3 and Figure 4 As shown, the locking assembly 9 and the cabinet door 5 form an integrated structure. The locking assembly 9 and the rack 11 form a meshing structure through the gear 10. The rack 11 and the moving rod 12 form an integrated structure. At the same time, the moving rod 12 and the locking buckle 14 form a limiting engagement structure through the positioning pin 13. The locking buckle 14 and the inspection window 8 form an integrated structure. Figure 5 and Figure 6 As shown, the elastic sliding mechanism also includes a movable plate 15 slidably connected to the inner surface of the inspection window 8, and a lifting plate 16 is mounted on the outer surface of the movable plate 15. A compression spring 17 is elastically connected between the lifting plate 16 and the inspection window 8. Simultaneously, a top plate 18 is rotatably connected to the outer surface of the lifting plate 16, and a tension spring 19 is elastically connected between the top plate 18 and the lower side of the lifting plate 16. A switch button 20 is connected to the upper side of the outer surface of the top plate 18, and the switch button 20 is rotatably connected to the outer end of the air switch 4. Figure 5 and Figure 6 As shown, the inspection window 8 forms an elastic lifting structure with the compression spring 17 and the moving plate 15, and the moving plate 15 and the lifting plate 16 form an integrated structure. Furthermore, the lifting plate 16 and the inspection window 8 form an embedded sealing structure, and the lifting plate 16 and the top plate 18 form a rotating structure. Figure 5 and Figure 6 As shown, the top plate 18 forms an elastic rotating structure with the lifting plate 16 through the tension spring 19, and the top plate 18 forms a pressing structure with the switch button 20.

[0026] When air switch 4 trips, the lifting plate 16 installed on the manual control moving plate 15 slides within the inspection window 8 to limit its movement. This controls the top plate 18 connected to the lifting plate 16 to rotate and press the switch button 20 installed on air switch 4 to reset it. If the switch button 20 fails to reset during the pressing process and causes a rapid downward movement, the top plate 18, which is elastically connected to the lifting plate 16, will press and rotate with the switch button 20 when it is closed, moving the top plate 18 down to the side below the switch button 20. This allows for a complete power-off and re-energization test. If the power can be restored directly, air switch 4 will function normally. If air switch 4 fails to power on, a professional can contact the electronic identification tag and the identification reader 7 to activate the motor installed on the locking assembly 9. This drives the gear 10 to rotate, engaging the positioning pin 13 assembled on the moving rod 12 of the adjusting rack 11. This pin stably disengages from the inner surface of the locking buckle 14 installed on the inspection window 8, allowing the inspection window 8 to be opened for maintenance of air switch 4. This improves the safety of the metering box 1 used outdoors.

[0027] Example 3: Figure 7 and Figure 8 The technical solution shown, based on Embodiment 2, further discloses the stability of the built-in cooling mechanism in the power metering box during operation, avoiding damage caused by internal water vapor accumulation in hot and rainy weather. It solves the problem that outdoor power metering boxes are prone to overheating in hot and rainy weather, affecting normal heat dissipation. The specific details are as follows: The crank-connecting rod mechanism also includes a turntable 22 rotatably connected to the inner surface of the ventilation assembly 21, and a connecting rod 23 rotatably connected to the outer surface of the turntable 22. An offset rod 24 is rotatably connected to the other end of the outer surface of the connecting rod 23, and a moisture-absorbing assembly 25 is installed on the outer surface of the offset rod 24; Figure 7 and Figure 8 As shown, the ventilation assembly 21 and the turntable 22 form a rotating structure, and the turntable 22 forms a crank-connecting rod structure with the offset rod 24 via the connecting rod 23. The offset rod 24 and the moisture-absorbing assembly 25 form an integrated structure, while the moisture-absorbing assembly 25 and the ventilation assembly 21 form a telescopic structure. Figure 7 and Figure 8 As shown, the inner surface of the moisture absorption component 25 is nested with moisture absorption material 26, and the upper surface of the ventilation component 21 is equipped with an intake fan 27. The lower side of the outer surface of the ventilation component 21 is provided with an air inlet 28, and the outer surface of the metering box 1 is provided with an air outlet 29. The moisture absorption component 25 and the moisture absorption material 26 form an embedded structure, and the moisture absorption material 26, the intake fan 27, and the air inlet 28 are arranged on the same central axis.

[0028] During hot and rainy weather, the motor of the ventilation component 21 installed in the automatic control metering box 1 is rotated, which drives the turntable 22 and the adjusting connecting rod 23 to rotate. The moisture absorption component 25 installed in the adjusting offset rod 24 slides within the ventilation component 21. In rainy weather, air can be introduced through the air inlet 28 connected to the fan 27. The moisture in the air is filtered by the moisture absorption material 26 installed in the moisture absorption component 25, and the air is discharged from the air outlet 29. This improves the stability of ventilation and cooling and solves the safety problem when the outdoor metering box 1 is cooling down.

[0029] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0030] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An outdoor safety-type intelligent power metering box, which is equipped with a metering box (1) and a power meter (2) assembled in the metering box (1). Its features are, include: A support rod (3) is installed on the inner surface of the metering box (1), and an air switch (4) is installed on the outer surface of the support rod (3). A cabinet door (5) is rotatably connected to the outer surface of the metering box (1). An observation window (6) is nested on the inner surface of the cabinet door (5). An identification device (7) is installed on the inner surface of the cabinet door (5). An inspection window (8) is rotatably connected to the inner surface of the cabinet door (5). A locking assembly (9) is installed on the inner wall of the cabinet door (5). The locking assembly (9) is connected to a locking buckle (14) through a meshing limiting mechanism. The inspection window (8) is connected to a top plate (18) through an elastic sliding mechanism. A ventilation assembly (21) is installed on the lower surface of the metering box (1). The ventilation assembly (21) is connected to a moisture-absorbing assembly (25) through a crank-connecting rod mechanism.

2. The outdoor safety intelligent power metering box according to claim 1, characterized in that: The metering box (1) is connected to the air switch (4) via the support rod (3) to form a limiting engagement structure. The metering box (1) and the cabinet door (5) form a rotating structure. The cabinet door (5) is embedded in the observation window (6) and the identity recognition device (7). At the same time, the cabinet door (5) and the inspection window (8) form a rotating structure.

3. The outdoor safety intelligent power metering box according to claim 1, characterized in that: The engagement limiting mechanism also includes a gear (10) rotatably connected to the inner surface of the locking assembly (9), and a rack (11) meshes with the outer surface of the gear (10), limiting the rack (11) to slide on the inner surface of the locking assembly (9). A moving rod (12) is installed on the outer surface of the rack (11), and a positioning pin (13) is installed on the outer surface of the moving rod (12). A locking buckle (14) is engaged with the outer surface of the positioning pin (13), and the locking buckle (14) is installed on the outer surface of the inspection window (8).

4. The outdoor safety intelligent power metering box according to claim 1, characterized in that: The locking assembly (9) and the cabinet door (5) form an integrated structure. The locking assembly (9) and the rack (11) form a meshing structure through the gear (10). The rack (11) and the moving rod (12) form an integrated structure. The moving rod (12) and the locking buckle (14) form a limiting engagement structure through the positioning pin (13). The locking buckle (14) and the inspection window (8) form an integrated structure.

5. An outdoor safety-type intelligent power metering box according to claim 1, characterized in that: The elastic sliding mechanism also includes a movable plate (15) that is slidably connected to the inner surface of the inspection window (8), and a lifting plate (16) is installed on the outer surface of the movable plate (15). A compression spring (17) is elastically connected between the lifting plate (16) and the inspection window (8). Meanwhile, a top plate (18) is rotatably connected to the outer surface of the lifting plate (16), and a tension spring (19) is elastically connected between the top plate (18) and the lower side of the lifting plate (16). A switch button (20) is connected to the upper side of the outer surface of the top plate (18), and the switch button (20) is rotatably connected to the outer end of the air switch (4).

6. An outdoor safety-type intelligent power metering box according to claim 1, characterized in that: The inspection window (8) is elastically lifted by compression spring (17) and moving plate (15), and the moving plate (15) and lifting plate (16) form an integrated structure. The lifting plate (16) and inspection window (8) form an embedded sealing structure, and the lifting plate (16) and top plate (18) form a rotating structure.

7. An outdoor safety-type intelligent power metering box according to claim 1, characterized in that: The top plate (18) forms an elastic rotating structure with the lifting plate (16) through the tension spring (19), and the top plate (18) forms a compression structure with the switch button (20).

8. An outdoor safety-type intelligent power metering box according to claim 1, characterized in that: The crank-connecting rod mechanism also includes a turntable (22) rotatably connected to the inner surface of the ventilation assembly (21), and a connecting rod (23) rotatably connected to the outer surface of the turntable (22), and an offset rod (24) rotatably connected to the other end of the outer surface of the connecting rod (23), while a moisture-absorbing assembly (25) is installed on the outer surface of the offset rod (24).

9. An outdoor safety-type intelligent power metering box according to claim 8, characterized in that: The ventilation component (21) and the turntable (22) form a rotating structure, and the turntable (22) and the offset rod (24) form a crank-connecting rod structure through the connecting rod (23). The offset rod (24) and the moisture absorption component (25) form an integrated structure, and the moisture absorption component (25) and the ventilation component (21) form a telescopic structure.

10. An outdoor safety-type intelligent power metering box according to claim 8, characterized in that: The inner surface of the moisture-absorbing component (25) is nested with moisture-absorbing material (26), and the upper surface of the ventilation component (21) is equipped with an air intake fan (27). The lower side of the outer surface of the ventilation component (21) is provided with an air inlet (28), and the outer surface of the metering box (1) is provided with an air outlet (29). The moisture-absorbing component (25) and the moisture-absorbing material (26) form an embedded structure, and the moisture-absorbing material (26), the air intake fan (27), and the air inlet (28) are arranged on the same central axis.