Power metering box

Abstract

The present invention provides an electric power metering box, belonging to the technical field of electric power equipment. Two adjacent side walls on one side of the box body are provided with installation openings, and two baffle plates are connected in the installation openings. The outer wall of the box body is fixedly connected with a motor, and the end of the output shaft of the motor penetrates through the box body and is connected with a fan. A heat dissipation hole is formed in the box body, and a driving chamber is arranged inside the top end of the box body. A driving pipe is fixedly connected in the driving chamber, and the driving pipe can drive the two baffle plates to rotate in the installation openings. The present invention completes the automatic opening of the two baffle plates through the cooperation of a gear and a rack, increases the ventilation area, improves the heat dissipation efficiency, and ensures the stability of the electrical appliances in the box body; after the two baffle plates are completely opened, the two first magnetic blocks attract each other to ensure the stability of the opened state of the baffle plates; the closing process of the two baffle plates is accelerated, and the stability of the closed state of the baffle plates is ensured; the technical problem of how to accelerate the internal heat dissipation when the temperature in the electric power meter is relatively high is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of power equipment, and particularly relates to a power metering box. Background Art

[0002] A power metering box can measure the electricity consumption in a circuit. An electric meter is a type of power metering box, which is widely used and has the advantages of high metering accuracy, light weight, convenient installation, and anti-stealing of electricity.

[0003] In power places with high electricity consumption, not only power metering devices are installed in the power metering box, but also various detection devices, signal transmission devices, etc. are connected in series, which can monitor the actual situation inside the box in real time through the network. During the process of increasing current in the metering box, the equipment inside continuously emits heat. The heat dissipation method of exhausting air through a fan inside the box is limited and cannot effectively achieve the purpose of rapid cooling. The continuous high temperature inside the box will cause damage to the internal electronic equipment, affecting the metering process and accuracy. Summary of the Invention

[0004] The purpose of the present invention is to provide a power metering box with increased internal heat dissipation efficiency to solve at least one of the technical problems in the above background art.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions:

[0006] The present invention provides a power metering box, including: a box body. Two adjacent side walls on one side of the box body are provided with installation openings. Two baffle plates are rotatably connected in the installation openings. A motor is fixedly connected to the outer wall of the box body. The end of the output shaft of the motor penetrates the box body and is fixedly connected with a fan. The box body is provided with heat dissipation holes. A driving chamber is opened inside the top end of the box body. A driving pipe is fixedly connected in the driving chamber. A first piston is slidably connected in the driving pipe. A mounting plate is fixedly connected to the side wall of the first piston. The end of the mounting plate penetrates the driving pipe and is fixedly connected with a toothed plate. Two mutually meshing gears are rotatably connected in the driving chamber. The two gears are respectively fixedly connected with the corresponding baffle plates. The first gear meshes with the toothed plate. A driving mechanism capable of driving the first piston to move is provided in the driving chamber.

[0007] Optionally, in order to be able to open the baffle plate to increase the heat dissipation efficiency when the temperature inside the box is high, the driving mechanism includes an intermediate box. The intermediate box is communicated with the driving pipe through a first pipeline. A first electric control valve is provided in the first pipeline. A temperature sensor is provided inside the box body. The temperature sensor is electrically connected to the first electric control valve. The air pressure inside the intermediate box is greater than the air pressure inside the driving pipe. A pressurization chamber is opened on the side wall of the box body. A pressurization mechanism is provided in the pressurization chamber, and the pressurization mechanism can pump gas into the intermediate box.

[0008] Optionally, in order to make the pressure of the gas in the intermediate box greater than the pressure of the gas in the drive pipe, the pressurizing mechanism includes a pressurizing pipe fixedly connected to the inner wall of the pressurizing chamber. A second piston is slidably connected in the pressurizing pipe. The second piston is elastically connected to the inner wall of the pressurizing pipe by a first spring. A trigger rod is fixedly connected to the side wall of the second piston. The end of the trigger rod penetrates through the pressurizing pipe and is slidably connected thereto. A cam is fixedly connected to the output shaft of the motor. The cam is located on one side of the trigger rod and cooperates with it. Two air delivery pipes are communicated on the same side of the pressurizing pipe. One-way valves are provided in both of the two air delivery pipes. The first air delivery pipe is communicated with the intermediate box.

[0009] Optionally, in order to be able to discharge the excess gas in the intermediate box, an exhaust pipe is communicated with the side wall of the intermediate box. A second electric control valve is provided in the exhaust pipe. The second electric control valve is electrically connected to the temperature sensor.

[0010] Optionally, in order to enable the two baffles to automatically reset, the first piston and the inner wall of the drive pipe are elastically connected by a second spring.

[0011] Optionally, in order to enable the two baffles to be in a stable state in the open state, movable chambers are respectively provided in the two baffles. Third pistons are hermetically and slidably connected in the two movable chambers. The third pistons and the inner walls of the movable chambers are elastically connected by third springs. First magnetic blocks are fixedly connected to the side walls of the two third pistons. The drive pipe is communicated with a second pipe on the same side as the first pipe. The second pipe is communicated with the two movable chambers through two branch pipes respectively. The two first magnetic blocks are in a first position when not pushed by air pressure. The two first magnetic blocks in the first position repel each other. The two first magnetic blocks are in a second position when pushed by air pressure. The two first magnetic blocks in the second position attract each other.

[0012] Optionally, in order to make the two baffles in a stable state in the closed state, a stepped surface adapted to the baffle is provided on the side wall of the box body. A second magnetic block is embedded in the stepped surface. The second magnetic block attracts the first magnetic block in the first position and repels the first magnetic block in the second position.

[0013] The beneficial effects of the present invention are as follows: The automatic opening of the two baffles is completed through the cooperation of the gear and the toothed plate, increasing the ventilation area, improving the heat dissipation efficiency, and ensuring the stability of the electrical appliances in the box body; after the two baffles are completely opened, the two first magnetic blocks attract each other, ensuring the stability of the open state of the baffles; the closing process of the two baffles is accelerated, and the stability of the closed state of the baffles is ensured.

[0014] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent from the following description, or be understood through the practice of the present invention. Brief Description of the Drawings

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0016] Figure 1 It is a three-dimensional structure diagram of the power metering box according to the embodiment of the present invention.

[0017] Figure 2 It is a structural diagram of the interior of the drive chamber according to the embodiment of the present invention.

[0018] Figure 3 It is a front view structural diagram of the power metering box according to the embodiment of the present invention.

[0019] Figure 4 is Figure 3 an enlarged view of the structure at A in

[0020] Figure 5 It is a side view structural diagram of the power metering box according to the embodiment of the present invention.

[0021] Wherein: 1 - box body; 2 - installation opening; 3 - baffle; 4 - stepped surface; 5 - toothed plate; 6 - fan; 7 - heat dissipation hole; 8 - motor; 9 - second magnet; 10 - movable chamber; 11 - branch pipe; 12 - third spring; 13 - third piston; 14 - first magnet; 15 - air delivery pipe; 16 - pressurizing pipe; 17 - pressurizing chamber; 18 - second piston; 19 - trigger rod; 20 - cam; 21 - intermediate box; 22 - exhaust pipe; 23 - first pipe; 24 - second pipe; 25 - drive pipe; 26 - second spring; 27 - first piston; 28 - mounting plate; 29 - gear; 30 - drive chamber. Detailed Embodiments

[0022] The embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described through the drawings are exemplary and are only used to explain the present invention and cannot be construed as a limitation of the present invention.

[0023] Those skilled in the art of the present technology can understand that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as the general understanding of those of ordinary skill in the art to which the present invention pertains.

[0024] It should also be understood that terms such as those defined in a general dictionary should be understood to have a meaning consistent with their meaning in the context of the prior art, and will not be interpreted with an idealized or overly formal meaning unless defined as herein.

[0025] Those skilled in the art of the present technology can understand that, unless specifically stated, the singular forms "a", "an", "the", and "said" used herein may also include the plural forms. It should be further understood that the term "comprising" used in the description of the present invention means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, and / or their groups.

[0026] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with that embodiment or example are included in at least one embodiment or example of the present invention. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0027] In the description of this specification, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" can explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "a plurality" is two or more, unless otherwise specifically defined.

[0028] In the description of this specification, the orientation or positional relationship indicated by terms such as "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present technology and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the present technology.

[0029] Unless otherwise clearly specified and defined, the terms "installation", "connection", "linkage", and "arrangement" shall be understood in a broad sense. For example, it can be fixedly connected or arranged, or detachably connected or arranged, or integrally connected or arranged. For those of ordinary skill in the art, the specific meanings of the above terms in the present technology can be understood according to specific circumstances.

[0030] To facilitate the understanding of the present invention, the following further explains the present invention with specific embodiments in conjunction with the accompanying drawings, and the specific embodiments do not constitute a limitation to the embodiments of the present invention.

[0031] Those skilled in the art should understand that the drawings are only schematic diagrams of the embodiments, and the components in the drawings are not necessarily essential for implementing the present invention.

[0032] Embodiment

[0033] As Figures 1 to 5 shown, in this embodiment, a power metering box is provided, which includes a box body 1. Two adjacent side walls on one side of the box body 1 are provided with installation openings 2. Two baffle plates 3 are rotatably connected in the installation openings 2. The positions where the two baffle plates 3 are rotatably connected to the box body 1 are on the same side. A motor 8 is fixedly connected to the outer wall of the box body 1. The end of the output shaft of the motor 8 penetrates the box body 1 and is fixedly connected to a fan 6. A heat dissipation hole 7 is provided on the box body 1. When the motor 8 drives the fan 6 to rotate, a cycle can be formed, and heat dissipation is achieved during the process of gas flow.

[0034] A driving chamber 30 is opened inside the top end of the box body 1. A driving pipe 25 is fixedly connected inside the driving chamber 30. A first piston 27 is slidably connected inside the driving pipe 25. A mounting plate 28 is fixedly connected to the side wall of the first piston 27. The end of the mounting plate 28 penetrates the driving pipe 25 and is fixedly connected to a toothed plate 5. Two mutually meshing gears 29 are rotatably connected inside the driving chamber 30. The two gears 29 are respectively fixedly connected to the corresponding baffle plates 3. The first gear 29 meshes with the toothed plate 5.

[0035] A driving mechanism capable of driving the first piston 27 to move is provided inside the driving chamber 30. When the driving mechanism drives the first piston 27 to move, the toothed plate 5 can be driven to move through the mounting plate 28. When the toothed plate 5 moves, the two gears 29 can be driven to rotate synchronously. When the gears 29 rotate, the two baffle plates 3 are synchronously opened.

[0036] When the temperature inside the box body 1 continuously exceeds the threshold and is at a high level, at this time, the two baffle plates 3 automatically open. When the two baffle plates 3 are opened, the fan 6 is located on the opposite side of the inner wall of the box body 1. Airflow can enter through one installation opening 2 and discharge from the other installation opening 2, forming a high-efficiency temperature airflow to continuously take away the heat inside the box body 1.

[0037] In a specific embodiment, the driving mechanism includes an intermediate box 21. The intermediate box 21 is communicated with a driving tube 25 through a first pipeline 23. A first electric control valve is provided in the first pipeline 23. A temperature sensor is provided in the box body 1 and is electrically connected to the first electric control valve. The air pressure in the intermediate box 21 is greater than the air pressure in the driving tube 25. When the temperature in the box body 1 exceeds the set temperature, it controls the first electric control valve in the first pipeline 23 to open at this time. After the first pipeline 23 is opened, the gas with relatively high pressure in the intermediate box 21 enters the driving tube 25 to push the first piston 27 to move, completing the driving process. A pressurizing chamber 17 is opened on the side wall of the box body 1, and a pressurizing mechanism is provided in the pressurizing chamber 17. The pressurizing mechanism can pump gas into the intermediate box 21, and by pumping gas into the intermediate box 21, the gas pressure in the intermediate box 21 is in a state of being greater than the gas pressure in the driving tube 25, realizing the reserve of power.

[0038] The pressurizing mechanism includes a pressurizing tube 16 fixedly connected to the inner wall of the pressurizing chamber 17. A second piston 18 is slidably connected in the pressurizing tube 16. The second piston 18 is elastically connected to the inner wall of the pressurizing tube 16 through a first spring. A trigger rod 19 is fixedly connected to the side wall of the second piston 18. The end of the trigger rod 19 penetrates through the pressurizing tube 16 and is slidably connected thereto. A cam 20 is fixedly connected to the output shaft of the motor 8.

[0039] The cam 20 is located on one side of the trigger rod 19 and cooperates with it. Two air inlet pipes 15 are communicated on the same side of the pressurizing tube 16. Check valves are provided in both of the two air inlet pipes 15. The first air inlet pipe 15 is communicated with the intermediate box 21. While driving the fan 6 to rotate for heat dissipation, the motor 8 can drive the cam 20 to continuously rotate. During the rotation of the cam 20, it can squeeze the trigger rod 19, and the trigger rod 19 pushes the second piston 18 to move. When the cam 20 is separated from the trigger rod 19, the second piston 18 can reset under the action of the first spring. During the reciprocating movement of the second piston 18, under the action of the check valves in the two air inlet pipes 15, the outside gas can be pumped into the intermediate box 21. During the process of the gas entering, the pressure in the intermediate box 21 is increased, maintaining the air pressure in the intermediate box 21 and preparing for driving the first piston 27 to move.

[0040] An exhaust pipe 22 is connected to the side wall of the middle box 21. A second electric control valve is arranged in the exhaust pipe 22. The second electric control valve is electrically connected to a temperature sensor. The first piston 27 is elastically connected to the inner wall of the drive pipe 25 through a second spring 26. When the temperature sensor detects that the temperature in the box body 1 returns to the normal range, it controls the opening of the first electric control valve and the second electric control valve at this time. At this time, the first piston 27 can be reset under the action of the second spring 26. The gas in the drive pipe 25 enters the middle box 21 through the first pipe 23 and is finally discharged through the exhaust pipe 22. At this time, the mounting plate 28 moves in the reverse direction. During the reverse movement process, it rotates the drive gear 29 again to realize the closing process of the two baffles 3. The temperature sensor is internally provided with an existing PLC control module, which can judge the temperature in the box body 1 and its current state, and then realizes the opening and closing of the first electric control valve and the second electric control valve.

[0041] Activity chambers 10 are respectively arranged in the two baffles 3. Third pistons 13 are hermetically and slidably connected in the two activity chambers 10. The third pistons 13 are elastically connected to the inner walls of the activity chambers 10 through third springs 12. First magnets 14 are fixedly connected to the side walls of the two third pistons 13. The pulling forces generated by the two third springs 12 are different. Under different pulling forces, the extreme positions that the two first magnets 14 can be in are different. It is also possible to set the lengths of the two activity chambers 10 to be different, so that the displacement distances of the two first magnets 14 are different. The drive pipe 25 is connected to a second pipe 24 on the same side as the first pipe 23. The second pipe 24 is respectively connected to the two activity chambers 10 through two branch pipes 11. When the first electric control valve in the first pipe 23 is opened, the pressurized gas can enter the activity chambers 10 through the second pipe 24 and the branch pipes 11 at this time, pushing the two third pistons 13 and the first magnets 14 to move. The two first magnets 14 are in the first position when not pushed by air pressure. The two first magnets 14 in the first position repel each other. The two first magnets 14 are in the second position after being pushed by air pressure. The two first magnets 14 in the second position attract each other. After the first electric control valve is opened, the first piston 27 is pushed by air pressure to move the rack 5 at this time, realizing the opening of the baffle 3. And at this time, the gas can enter the activity chambers 10 through the second pipe 24 to control the two first magnets 14 to be in the second position. At this time, the two first magnets 14 attract each other, which can ensure that the two baffles 3 are in a stable state when opened.

[0042] Figure 3 As shown, the first baffle 3 is sectioned by a curve to more clearly show the internal structure. The actual situation is continuous.

[0043] A stepped surface 4 adapted to the baffle 3 is formed on the side wall of the box body 1. A second magnetic block 9 is embedded in the stepped surface 4. The second magnetic block 9 attracts the first magnetic block 14 in the first position and repels the first magnetic block 14 in the second position. When the air pressure in the intermediate box 21 decreases, the first piston 27 is reset under the action of the second spring 26 at this time. The two first magnetic blocks 14 are reset to the first position under the action of the third spring 12. The two first magnetic blocks 14 repel each other, causing the two baffles 3 to bounce open rapidly during the acceleration reset process. And when the baffle 3 rotates to the stepped surface 4.

[0044] Among them, the first magnetic block 14 in the first position can attract the corresponding second magnetic block 9, quickly close the baffle 3, and keep it in a stable state under normal conditions.

[0045] During the working process of the power metering box according to the embodiment of the present invention, when the temperature sensor detects that the temperature inside the box body 1 rises, it controls the motor 8 to drive the fan 6 to rotate at this time. The gas is exchanged through the heat dissipation holes 7 to achieve heat dissipation, thereby reducing the temperature inside the box body 1. And during this process, the pressurizing mechanism continuously works to pump gas into the intermediate box 21 to increase the air pressure inside the intermediate box 21.

[0046] When the temperature inside the box body 1 continues to rise and remains at a high level, the first electric control valve in the first pipeline 23 opens at this time. The gas with pressure in the intermediate box 21 enters the two movable chambers 10 through the first pipeline 23 and the second pipeline 24, pushing the positions of the two first magnetic blocks 14 to change, changing the position of the first magnetic block 14 to make it in a repulsive state with the second magnetic block 9. At this time, the two baffles 3 tend to open outwards. And the gas enters the driving pipe 25 to push the first piston 27 to move. The first piston 27 drives the toothed plate 5 on one side of the mounting plate 28 to drive the two gears 29 to rotate, realizing the automatic opening of the two baffles 3. When the two baffles 3 are in the open state, the ventilation area is increased. The external air flow can enter through one mounting port 2 and discharge from the other mounting port 2, realizing the directional flow of the gas and completing the ventilation and heat dissipation process.

[0047] When the temperature inside the box body 1 is in a normal state, the temperature sensor receives a signal to open the second electric control valve in the exhaust pipe 22. At this time, the gas in the intermediate box 21, the drive pipe 25, and the movable chamber 10 is discharged. The first piston 27 is reset under the action of the second spring 26, and the third piston 13 is reset under the action of the third spring 12. At this time, the two first magnetic blocks 14 are in a mutually repulsive state, and there is a tendency for the two baffles 3 to close rapidly. During the movement of the mounting plate 28, the gear 29 is driven to reverse, thereby completing the closing of the baffle 3, and the baffle 3 can be kept stable under the mutual attraction of the second magnetic block 9 and the first magnetic block 14. Compared with controlling the opening and closing of the baffle 3 by an automatically programmed motor, this device is more reasonable and stable, has an extremely low failure rate, and can ensure that the baffle 3 is in a stable state whether it is in the open or closed state.

[0048] In summary, for the power metering box described in the embodiment of the present invention, when the temperature inside the box body rises and remains at a high level, the opening and closing of the first pipeline are controlled at this time. The gas in the intermediate box enters the drive pipe to push the first piston to move, and the two baffles are automatically opened through the gear and rack, increasing the ventilation area and the heat dissipation efficiency, and ensuring the stability of the electrical appliances inside the box body. The gas entering the movable chamber can change the positions of the two first magnetic blocks to make them in different positions. When the baffle is in the open state, the two first magnetic blocks can mutually repel the corresponding second magnetic blocks, accelerating the opening process. After the two baffles are completely opened, the two first magnetic blocks attract each other to ensure the stability of the open state of the baffle. When the second electric control valve in the exhaust pipe is opened and the baffle is in the closing process, at this time, the positions of the two first magnetic blocks are reset and they repel each other, which can accelerate the closing process of the two baffles, and in this state, the two first magnetic blocks can respectively attract the corresponding second magnetic blocks to ensure the stability of the closed state of the baffle.

[0049] Although the specific implementation manners of the present invention have been described above in conjunction with the accompanying drawings, it is not a limitation to the protection scope of the present invention. Those skilled in the art should understand that based on the technical solutions disclosed in the present invention, various modifications or deformations that can be made by those skilled in the art without creative efforts should be covered within the protection scope of the present invention.

Claims

1. A power metering box, characterized in that, it includes: a box body (1), two side walls adjacent to one side of the box body (1) are provided with installation openings (2), two baffles (3) are connected in the installation openings (2), an outer wall of the box body (1) is fixedly connected with a motor (8), an end of an output shaft of the motor (8) penetrates through the box body (1) and is connected with a fan (6), heat dissipation holes (7) are formed in the box body (1), a driving chamber (30) is arranged inside the top end of the box body (1), a driving pipe (25) is fixedly connected in the driving chamber (30), and the driving pipe (25) drives the two baffles (3) to rotate in the installation openings (2); a pressurizing chamber (17) is arranged on a side wall of the box body (1), and a pressurizing mechanism is arranged in the pressurizing chamber (17), wherein the pressurizing mechanism can pump gas into an intermediate box (21); a first piston (27) is slidably connected in the driving pipe (25); The pressurizing mechanism includes a pressurizing pipe (16) fixedly connected to an inner wall of the pressurizing chamber (17), a second piston (18) is slidably connected in the pressurizing pipe (16), the second piston (18) is elastically connected to an inner wall of the pressurizing pipe (16) through a first spring, a trigger rod (19) is fixedly connected to a side wall of the second piston (18), and an end of the trigger rod (19) penetrates through the pressurizing pipe (16) and is slidably connected thereto; a cam (20) is fixedly connected to an output shaft of the motor (8), the cam (20) is located on one side of the trigger rod (19) and cooperates with the trigger rod (19), two air delivery pipes (15) are communicated on the same side of the pressurizing pipe (16), one-way valves are arranged in both of the two air delivery pipes (15), and one of the air delivery pipes (15) is communicated with the intermediate box (21); Activity chambers (10) are respectively arranged in the two baffles (3), third pistons (13) are hermetically and slidably connected in the two activity chambers (10), the third pistons (13) are elastically connected to inner walls of the activity chambers (10) through third springs (12), pulling forces generated by the two third springs (12) are different, first magnets (14) are fixedly connected to side walls of the two third pistons (13), the driving pipe (25) is communicated with a second pipe (24) on the same side as a first pipe (23), and the second pipe (24) is communicated with the two activity chambers (10) through two branch pipes (11).

2. The power metering box according to claim 1, characterized in that, a mounting plate (28) is fixedly connected to a side wall of the first piston (27), an end of the mounting plate (28) penetrates through the driving pipe (25) and is fixedly connected with a toothed plate (5), two gears (29) meshing with each other are rotatably connected in the driving chamber (30), and the two gears (29) are respectively fixedly connected with corresponding baffles (3); a driving mechanism capable of driving the first piston (27) to move is arranged in the driving chamber (30).

3. The power metering box according to claim 2, characterized in that, The driving mechanism includes an intermediate box (21), which is communicated with the driving pipe (25) through a first pipeline (23). A first electric control valve is arranged in the first pipeline (23). A temperature sensor is arranged in the box body (1), and the temperature sensor is electrically connected to the first electric control valve.

4. The power metering box according to claim 1, characterized in that an exhaust pipe (22) is communicated with the side wall of the intermediate box (21). A second electric control valve is arranged in the exhaust pipe (22), and the second electric control valve is electrically connected to the temperature sensor.

5. The power metering box according to claim 4, characterized in that the first piston (27) is elastically connected to the inner wall of the driving pipe (25) through a second spring (26).

6. The power metering box according to claim 5, characterized in that a stepped surface (4) adapted to the baffle (3) is arranged on the side wall of the box body (1). A second magnetic block (9) is embedded in the stepped surface (4). When not pushed by air pressure, the two first magnetic blocks (14) are in a first position. When pushed by air pressure, the two first magnetic blocks (14) are in a second position. The second magnetic block (9) attracts the first magnetic block (14) in the first position, and the second magnetic block (9) repels the first magnetic block (14) in the second position.

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