A waterproof air duct

Abstract

The present invention relates to a waterproof air duct, which comprises a tube body and a filter element. One end of the tube body is connected to the outside air, and the other end is connected to the engine. The filter element is arranged in the tube body and is rotatably connected to the inner wall of the tube body. The filter element is a disc-shaped structure. The filter element can be rotated to a first position and a second position. When the filter element is rotated to the first position, the filter element is arranged parallel to the air flow direction in the tube body. When the filter element is rotated to the second position, the filter element is arranged perpendicular to the air flow direction in the tube body, and the outer peripheral wall of the filter element is arranged close to the inner wall of the tube body. The air in the tube body is filtered by the filter element and then transported to the engine. The problem that the air duct structure in the prior art cannot have both the effects of waterproofing and ensuring the amount of air entering is solved.

Description

Technical Field

[0001] The invention relates to the technical field of automobile engine air intake systems, and in particular to a waterproof air duct. Background Art

[0002] At present, the air duct used in the air intake system of automobile engines adopts a straight-through type. When the engine is working, air is inhaled from the air duct of the intake system. The pipeline adopts a straight-through type. The inhaled air is directly filtered through the air filter to remove water vapor in the air. Finally, the air is inhaled into the engine cylinder and fully mixed with the fuel to burn and do work.

[0003] The air duct of the engine is one of the most important components in the air intake system. The quality of the air duct design will directly affect the engine intake performance. In the prior art, in order to improve the engine intake performance, the air duct structure is various. For example, the Chinese utility model patent with patent application number CN202021594583.2 proposes a new air duct assembly, which includes an air duct body for engine intake. The air duct body is a double air duct structure and an intake volume control structure provided in the double air duct structure. The double air duct structure includes two connected air duct branches. The ends of the two air bleed branches form two independent air inlets. The above-mentioned prior art adopts a double air inlet structure to increase the air intake volume of the automobile intake system. However, it does not take the waterproof problem into consideration. When the engine is working, the intake system generates negative pressure to suck water vapor and other debris into the straight-through pipeline. Increasing the air intake volume of the air bleed pipe blindly will cause excessive water vapor to be sucked in. When excessive water vapor enters the engine, it will damage the engine and even cause cylinder scuffing, affecting the normal operation of the engine. If a filtering mechanism is set on the air bleed pipe, it will hinder the entry of gas and cannot guarantee the amount of air entering.

[0004] Therefore, when a filter mechanism is provided on the air duct in the prior art, air entry will be blocked. When no filter mechanism is provided, water vapor will enter the engine, which may easily cause damage to the engine. As a result, the air duct structure in the prior art cannot achieve both waterproofing and the effect of ensuring the amount of air entering. Summary of the invention

[0005] In view of this, it is necessary to provide a waterproof air duct to solve the problem that the air duct structure in the prior art cannot have both waterproof and air intake guarantee effects.

[0006] The present invention provides a waterproof air duct comprising a tube body and a filter element, wherein one end of the tube body is connected to the outside air, and the other end is connected to the engine, the filter element is arranged in the tube body and is rotatably connected to the inner wall of the tube body, the filter element is a disc-shaped structure, and the filter element can be rotated to a first position and a second position. When the filter element is rotated to the first position, the filter element is arranged parallel to the air flow direction in the tube body, and when the filter element is rotated to the second position, the filter element is arranged perpendicular to the air flow direction in the tube body, and the outer peripheral wall of the filter element is arranged in contact with the inner wall of the tube body, and the air in the tube body is filtered by the filter element and then transported to the engine.

[0007] Furthermore, the tube body has an air intake portion and an expansion portion, one end of the air intake portion is connected to the outside air, and the other end is connected to the expansion portion, the middle portion of the air intake portion is recessed downward, and a drain outlet is provided at the lowest point of the recessed position of the air intake portion, the filter element is arranged in the expansion portion, and the expansion portion is connected to the engine.

[0008] Furthermore, a drainage bag is fixedly provided on the drainage port, and a drainage portion is provided at the bottom end of the drainage bag. The drainage portion is a plate-like structure, and a drainage gap is provided on the drainage portion. The drainage gap connects the air inlet portion with the external environment.

[0009] Furthermore, one end of the air intake portion connected to the outside air is an air inlet with an opening facing upward, and the air intake portion is fixedly provided with an air bleed cap at the position of the air inlet. The upper end surface of the air bleed cap is closed and the lower end surface is open. The air inlet is located inside the air bleed cap, and a lip is fixedly provided on the lower end surface of the air bleed cap.

[0010] Furthermore, a filter screen is fixedly provided at the opening of the lower end surface of the air inlet cap, the filter screen is a wire mesh structure, the air inlet portion is provided through the filter screen, and the filter screen is fixedly connected to the outer peripheral wall of the air inlet portion.

[0011] Furthermore, the filter element includes a filter body frame and an air filter body, the filter body frame is arranged in an annular structure, the air filter body is fixedly connected to the inner wall of the filter body frame, the outer peripheral wall of the filter body frame is a rounded structure, and when the filter element is rotated to the second position, the outer peripheral wall of the filter body frame is arranged in line contact with the inner wall of the expansion part.

[0012] Furthermore, the filter body skeleton is rotatably connected to the inner wall of the expansion portion via a rotating shaft, the rotating shaft is arranged perpendicular to the axis of the expansion portion, and the rotating shaft passes through the filter body skeleton and the air filter body along the diameter direction of the filter body skeleton. Both ends of the rotating shaft are rotatably connected to the expansion portion, and at least one end is arranged through the expansion portion.

[0013] Furthermore, the expansion portion is connected to the engine via a connecting portion, one end of the connecting portion is sleeved on the expansion portion, and the other end is connected to the engine, both ends of the rotating shaft pass through the expansion portion and the connecting portion, two installation grooves are symmetrically opened on the outer periphery of the expansion portion close to one end of the connecting portion, four fastening grooves are evenly opened along the circumferential direction on the outer peripheral wall of the connecting portion, two of the installation grooves are arranged corresponding to any two oppositely arranged fastening grooves, and the ends of the installation grooves opposite to the fastening grooves are both open, and the rotating shaft can slide along the length direction of the installation grooves and the fastening grooves, and a clamp is sleeved on the connecting portion to compress the fastening groove to press and fix the connecting portion on the expansion portion.

[0014] Furthermore, both ends of the rotating shaft are rotatably connected to the expansion part via a bearing, and the ends of the installation groove and the fastening groove away from their own open ends are respectively connected to each other and are provided with a first bearing hole and a second bearing hole, and when the connecting part is pressed and fixed on the expansion part, the bearing is embedded in the first bearing hole and the second bearing hole.

[0015] Furthermore, either end of the rotating shaft passes through the bearing, a motor is fixedly arranged on the connecting portion, and gears that are meshed with each other are respectively mounted and fixed on the rotating shaft of the motor and the end of the rotating shaft passing through the bearing, and a humidity sensor is fixedly arranged on the outer periphery of the air inlet portion. The humidity sensor is electrically connected to the motor and can control the motor to drive the filter body frame to reciprocate between the first position and the second position through the rotating shaft.

[0016] Compared with the prior art, the waterproof air duct provided by the present invention can adjust the filtering state and filtering position of the filter element according to actual needs by arranging a rotatable filter element in the tube body. When there is too much water vapor in the air, the air can be effectively filtered by the filter element. When the air is dry, the filter element can be retracted by rotating it, and the operation of the filter element can be stopped so that it has no obstruction effect on the circulation of air, so as to ensure the amount of air entering the air duct. Specifically, the filter element is a disc-shaped structure, and the filter element has a first position and a second position. When the air is dry, the filter element can be rotated to the first position so that it is set parallel to the flow direction of the air in the tube body. At this time, the filter element does not work and has no obstruction effect on the air, so as to ensure the amount of air entering the air duct. When the air is humid and has a high water vapor content, the filter element can be rotated to the second position so that the filter element is set perpendicular to the flow direction of the air in the tube body. At this time, the air in the tube body needs to be filtered by the filter element before it can be transported to the engine, so as to filter out water vapor in the air, avoid water vapor from entering the engine, and increase the service life of the engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1A schematic diagram of the overall structure of an embodiment of a waterproof air duct provided by the present invention;

[0018] Figure 2 An exploded schematic diagram of an expansion portion and a connection portion in an embodiment of a waterproof air duct provided by the present invention;

[0019] Figure 3 for Figure 2 A magnified schematic diagram of part A;

[0020] Figure 4 An exploded schematic diagram of the connection structure between the filter element and the expansion portion in one embodiment of the waterproof air duct provided by the present invention.

[0021] In the figure: 1. tube body; 2. filter element; 3. rotating shaft; 31. rotating shaft; 4. motor; 5. humidity sensor; 11. air inlet; 12. expansion part; 13. connecting part; 111. drainage outlet; 112. drainage bag; 113. drainage part; 1131. drainage gap; 114. air inlet; 115. air bleed cap; 1151. lip; 1152. filter net; 21. filter body frame; 22. air filter body; 121. mounting groove; 122. first bearing hole; 131. fastening groove; 132. second bearing hole. DETAILED DESCRIPTION

[0022] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0023] like Figure 1-2 As shown, a waterproof air duct in this embodiment includes a tube body 1 and a filter element 2. One end of the tube body 1 is connected to the outside air, and the other end is connected to the engine. The filter element 2 is arranged in the tube body 1 and is rotatably connected to the inner wall of the tube body 1. The filter element 2 is a disc-shaped structure. The filter element 2 can be rotated to a first position and a second position. When the filter element 2 is rotated to the first position, the filter element 2 is arranged parallel to the air flow direction in the tube body 1. When the filter element 2 is rotated to the second position, the filter element 2 is arranged perpendicular to the air flow direction in the tube body 1, and the outer peripheral wall of the filter element 2 is arranged against the inner wall of the tube body 1. The air in the tube body 1 is filtered by the filter element 2 and then transported to the engine.

[0024] The tube body 1 is a gas passage for air circulation, and the outside air flows into the engine through the tube body 1; the filter element 2 is a mechanism for filtering air, which is mainly used to filter out water vapor in the air to prevent water vapor from entering the engine and affecting the service life of the engine. The filter element 2 is rotatably connected to the inner wall of the tube body 1, and the filter element 2 is set to a disc-shaped structure. The filter element 2 has a first position and a second position. When the air humidity is low and the water vapor content in the air is low, the filter element 2 can be rotated to the first position to make the filter element 2 parallel to the flow direction of the air in the tube body 1. When the air humidity is high and the water vapor content in the air is high, the filter element 2 can be rotated to the second position, so that the filter element 2 is arranged perpendicular to the flow direction of the air in the tube body 1. At this time, the outer peripheral wall of the filter element 2 is arranged against the inner wall of the tube body 1. The air in the tube body 1 needs to be filtered by the filter element 2 before it can be transported to the engine to filter out the water vapor in the air and avoid excessive water vapor from entering the engine and causing damage to the engine.

[0025] In this embodiment, the tube body 1 connects the outside air and the engine, providing a channel for the transportation of air. At the same time, the tube body 1 is also the first line of defense for the outside air to enter the engine. In order to reduce the amount of dirt and water vapor entering the engine with the air, the structure of the tube body 1 is improved in the following embodiments.

[0026] In order to reduce the entry of water vapor into the engine, in a preferred embodiment, the tube body 1 has an air intake portion 11 and an expansion portion 12. One end of the air intake portion 11 is connected to the outside air, and the other end is connected to the expansion portion 12. The middle portion of the air intake portion 11 is recessed downward, and a drain outlet 111 is provided at the lowest point of the recessed position of the air intake portion 11. The filter element 2 is arranged in the expansion portion 12, and the expansion portion 12 is connected to the engine.

[0027] Among them, the inner diameter of the expansion part 12 is larger than the inner diameter of the intake part 11. When the air flows to the expansion part 12, the air flow area becomes larger and the air flow rate becomes slower. The water vapor in the air gathers in the expansion part 12 and adheres to the tube wall. Under the action of gravity, it slides to the depression of the intake part 11 and is discharged through the drain port 111 opened in the depression, thereby avoiding the accumulation of a large amount of water vapor in the tube body 1, discharging the water vapor in time, and reducing the water vapor entering the engine.

[0028] In order to prevent water vapor and dirt from entering the pipe body 1 through the drain port 111, in a preferred embodiment, Figure 2-3 As shown, a drainage bag 112 is fixedly provided on the drainage port 111, and the bottom end of the drainage bag 112 has a drainage portion 113, the drainage portion 113 is a plate-like structure, and a drainage gap 1131 is provided on the drainage portion 113, and the drainage gap 1131 connects the air inlet portion 11 with the external environment.

[0029] Among them, the drainage bag is a bag-shaped structure fixedly arranged at the drainage outlet, and a drainage part 113 is fixed at its lower end. The drainage part 113 has a drainage gap 1131. The drainage gap 1131 is a narrow drainage channel. The water flow and water vapor in the drainage bag 112 can be discharged to the outside under the action of gravity. It is difficult for external liquid, water vapor and dirt to enter the drainage bag 112 through the drainage gap 1131, and it is also impossible to enter the tube body 1, thereby avoiding the introduction of water vapor and dirt from the drainage outlet 111 into the tube body 1 and the engine.

[0030] In order to further prevent rainwater and dirt from entering the pipe body 1, in a preferred embodiment, Figure 1-2 As shown, one end of the air intake portion 11 connected to the outside air is an air intake port 114 with an opening facing upward, and the air intake portion 11 is fixedly provided with an air inlet cap 115 at the position of the air inlet port 114. The upper end surface of the air inlet cap 115 is closed, and the lower end surface is open. The air inlet port 114 is located inside the air inlet cap 115, and a circle of lip edge 1151 is fixedly provided on the lower end surface of the air inlet cap 115.

[0031] Among them, in order to prevent dust, water and other debris on the bottom of the vehicle from being stirred up and falling into the tube body 1 during driving, the air inlet 114 of the tube body 1 is set upward so that it has a certain height difference with the ground to reduce the entry of dirt. The air inlet cap 115 is suspended and fixed above the air inlet 114, and the upper part of the air inlet cap 115 is closed to protect the air inlet 114 to prevent dirt or water from entering the tube body 1 from above the air inlet 114. When the tube body 1 inhales, the gas enters the air inlet 114 from the opening below the air inlet cap 115. The lip 1151 fixedly set on the lower end surface of the air inlet cap 115 is to make the dirt sliding down the air inlet cap 115 move in the direction away from the air inlet 114 to prevent the dirt from being accidentally sucked into the tube body 1 when the tube body 1 inhales.

[0032] In order to prevent large particles of dirt from entering the tube body 1, in a preferred embodiment, a filter screen 1152 is fixedly installed at the opening of the lower end surface of the air inlet cap 115. The filter screen 1152 is a wire mesh structure. The air inlet part 11 is arranged through the filter screen 1152, and the filter screen 1152 is fixedly connected to the outer peripheral wall of the air inlet part 11.

[0033] Among them, the filter net 1152 is arranged in an annular structure as a whole, the outer peripheral wall of the annular structure is fixedly connected to the inner wall of the air inlet cap 115, and the inner peripheral wall of the annular structure is fixedly connected to the outer peripheral wall of the air inlet part 11, so as to intercept the air inlet channel between the air inlet part 11 and the air inlet cap 115 to intercept the dirt that may enter the air inlet part 11.

[0034] In this embodiment, the filter element 2 is arranged in the tube body 1 and is rotatably connected to the inner wall of the tube body 1 for switching the working state and position. The filter element 2 is a disc-shaped structure, and the outer peripheral wall of the disc structure can be arranged to fit the inner wall of the tube body 1 to intercept the air flow channel in the tube body 1, so that the air needs to be filtered by the filter element 2 before it can be transported to the engine.

[0035] In order to make the filter element 2 rotate smoothly, in a preferred embodiment, Figure 2 and 4 As shown, the filter element 2 includes a filter body skeleton 21 and an air filter body 22. The filter body skeleton 21 is arranged in an annular structure. The air filter body 22 is fixedly connected to the inner wall of the filter body skeleton 21. The outer peripheral wall of the filter body skeleton 21 is a rounded structure. When the filter element 2 is rotated to the second position, the outer peripheral wall of the filter body skeleton 21 is arranged in line contact with the inner wall of the expansion portion 12.

[0036] Among them, the filter body skeleton 21 is a skeleton structure for fixing the air filter body 22. The filter body skeleton 21 is annular, and the air filter body 22 is embedded and fixed in the filter body skeleton 21. The outer peripheral wall of the filter body skeleton 21 is a rounded structure, so that when it is rotated to the second position, the outer peripheral wall is in line contact with the inner wall of the expansion part 12, so that the air can be filtered through the air filter body 22 before it can be transported to the engine. At the same time, the line contact structural design, when rotating, the filter body skeleton 21 will not interfere with the inner wall of the expansion part 12, so that the filter body skeleton 21 can freely rotate back and forth between the first position and the second position.

[0037] It should be noted that the air filter 22 in this embodiment also has the function of filtering dust.

[0038] In order to realize the rotational connection between the filter element 2 and the inner wall of the tube body 1, in a preferred embodiment, the filter body skeleton 21 is rotationally connected to the inner wall of the expansion portion 12 via a rotating shaft 313, and the rotating shaft 313 is arranged perpendicular to the axis of the expansion portion 12. The rotating shaft 313 is penetrated through the filter body skeleton 21 and the air filter body 22 along the diameter direction of the filter body skeleton 21, and both ends of the rotating shaft 313 are rotationally connected to the expansion portion 12, and at least one end is arranged through the expansion portion 12.

[0039] Among them, both ends of the rotating shaft 313 are rotatably connected to the tube wall of the expansion part 12, and one end of the rotating shaft 313 is set through the expansion part 12. The effect of driving the filter element 2 to rotate can be achieved by driving the rotating shaft 313 to rotate through the end of the expansion part 12.

[0040] In order to facilitate the installation of the filter element 2, in a preferred embodiment, as Figure 1-4As shown, the expansion portion 12 is connected to the engine via a connecting portion 13, one end of the connecting portion 13 is sleeved on the expansion portion 12, and the other end is connected to the engine, both ends of the rotating shaft 313 pass through the expansion portion 12 and the connecting portion 13, two installation grooves 121 are symmetrically provided on the outer periphery of the expansion portion 12 close to one end of the connecting portion 13, four fastening grooves 131 are evenly provided on the outer peripheral wall of the connecting portion 13 along the circumferential direction, the two installation grooves 121 are corresponding to any two oppositely arranged fastening grooves 131, the ends of the installation grooves 121 and the fastening grooves 131 opposite to each other are both open, the rotating shaft 313 can slide along the length direction of the installation grooves 121 and the fastening grooves 131, and a clamp (not shown in the figure) is sleeved on the connecting portion 13 to compress the fastening grooves 131 to press and fix the connecting portion 13 on the expansion portion 12.

[0041] The width of the installation groove 121 and the fastening groove 131 is greater than the outer diameter of the rotating shaft 313. When installing the filter element 2, the rotating shaft 313 is firstly inserted and fixed in the filter body frame 21 and the air filter body 22, and then the filter body frame 21 is aligned with the pipe opening of the expansion part 12, so that the rotating shaft 313 protruding from the pipe wall of the expansion part 12 is aligned with the installation groove 121, and the rotating shaft 313 and the filter body frame 21 are driven to slide toward the expansion part 12 along the length direction of the installation groove 121, thereby completing the installation of the rotating shaft 313 and the filter element 2. When installing the connecting part 13, firstly align the two The relatively arranged fastening grooves 131 are respectively aligned with the two mounting grooves 121, and then the connecting part 13 is driven to move toward the rotating shaft 313 until the closed end of the fastening groove 131 abuts against the rotating shaft 313, and finally the width of the fastening groove 131 is compressed by the clamp so that the connecting part 13 and the expansion part 12 are clamped and fixed. At this time, the rotating shaft 313 is clamped between the mounting groove 121 and the inner wall of the fastening groove 131, and the rotating shaft 313 is restricted from moving, but can rotate around its own axis; the above-mentioned structure is arranged to facilitate the disassembly and assembly of the filter element 2, and the filter element 2 can be replaced in time after being used for a certain period of time.

[0042] In order to make the rotation of the rotating shaft 313 smoother, in a preferred embodiment, both ends of the rotating shaft 313 are rotatably connected to the expansion part 12 via a bearing, and the mounting groove 121 and the fastening groove 131 are connected at one end away from their own open ends and are respectively provided with a first bearing hole 122 and a second bearing hole 132. When the connecting part 13 is pressed and fixed on the expansion part 12, the bearings are embedded in the first bearing hole 122 and the second bearing hole 132.

[0043] Among them, the outer diameter of the rotating shaft 313 is consistent with the inner diameter of the first bearing hole 122 and the second bearing hole 132. When installing the bearing, first move the rotating shaft 313 to the specified position, then sleeve the connecting part 13 on the expansion part 12, so that the rotating shaft 313 is inserted into the first bearing hole 122 and the second bearing hole 132, and then sleeve the bearing on both ends of the rotating shaft 313, and drive the bearing to move into the first bearing hole 122 and the second bearing hole 132, so that the bearing is located in the first bearing hole 122 and the second bearing, and finally compress the fastening groove 131 and the second bearing hole 132 through the clamp, so that the bearing is embedded and fixed in the second bearing hole 132, thereby completing the installation of the bearing.

[0044] In order to automatically control the working state of the filter element 2 according to the air humidity, in a preferred embodiment, either end of the rotating shaft 313 passes through the bearing, a motor 4 is fixedly installed on the connecting part 13, and the rotating shaft of the motor 4 and the end of the rotating shaft 313 passing through the bearing are respectively sleeved and fixed with gears that are meshed with each other, and a humidity sensor 5 is fixedly installed on the outer periphery of the air inlet part 11. The humidity sensor 5 is electrically connected to the motor 4, and can control the motor 4 to drive the filter body skeleton 21 to reciprocate between the first position and the second position through the rotating shaft 313.

[0045] Among them, the motor 4 is a driving structure for driving the rotating shaft 313 to rotate. The motor 4 is electrically connected to the humidity sensor 5. The humidity sensor 5 is fixedly arranged on the outer peripheral wall of the air inlet part 11 to detect the air humidity in the external environment. The motor 4 is controlled to work according to the detected result, so that the motor 4 drives the rotating shaft 313 to drive the filter element 2 to rotate between the first position and the second position. When the humidity sensor 5 detects that the humidity of the external environment is low, the filter element 2 is driven to rotate to the first position through the motor 4. When the humidity sensor 5 detects that the humidity of the external environment is too high, the filter element 2 is driven to rotate to the second position through the motor 4, so that the filter element 2 can automatically switch the working state and position according to the external environment, so that the air duct provided in this embodiment has the effects of both waterproofing and ensuring the amount of air entering.

[0046] Compared with the prior art: the waterproof air duct provided by the present invention can adjust the filtering state and filtering position of the filter element 2 according to actual needs by setting a rotatable filter element 2 in the tube body 1. When there is too much water vapor in the air, the air can be effectively filtered by the filter element 2. When the air is dry, the filter element 2 can be retracted by rotating it, and the filter element 2 can be stopped to prevent it from hindering the circulation of the air, so as to ensure the amount of air entering the air duct; specifically, the filter element 2 is a disc-shaped structure, and the filter element 2 has a first position and a second position. When the air is dry, the filter element 2 can be rotated to the first position so that it is arranged parallel to the flow direction of the air in the tube body 1. At this time, the filter element 2 does not work and has no obstruction effect on the air, so as to ensure the amount of air entering the air duct. When the air is humid and has a high water vapor content, the filter element 2 can be rotated to the second position so that the filter element 2 is arranged perpendicular to the flow direction of the air in the tube body 1. At this time, the air in the tube body 1 needs to be filtered by the filter element 2 before it can be transported to the engine, so as to filter out the water vapor in the air, prevent the water vapor from entering the engine, and improve the service life of the engine.

[0047] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A waterproof air duct, characterized in that: Including a tube body and a filter element; One end of the tube is connected to the outside air, and the other end is connected to the engine; The filter element is arranged in the tube body and is rotatably connected with the inner wall of the tube body. The filter element is a disc-shaped structure. The filter element can be rotated to a first position and a second position. When the filter element is rotated to the first position, the filter element is arranged parallel to the air flow direction in the tube body. When the filter element is rotated to the second position, the filter element is arranged perpendicular to the air flow direction in the tube body, and the outer peripheral wall of the filter element is arranged in contact with the inner wall of the tube body. The air in the tube body is filtered by the filter element and then transported to the engine. The tube body comprises an air intake portion and an expansion portion, one end of the air intake portion is connected to the outside air, and the other end is connected to the expansion portion, the middle portion of the air intake portion is recessed downward, a drainage port is provided at the lowest position of the recessed position of the air intake portion, the filter element is arranged in the expansion portion, the expansion portion is connected to the engine, and the inner diameter of the expansion portion is larger than the inner diameter of the air intake portion; The filter element comprises a filter frame and an air filter body, the filter frame is arranged in an annular structure, the air filter body is fixedly connected to the inner wall of the filter frame, the outer peripheral wall of the filter frame is a rounded structure, and when the filter element rotates to the second position, the outer peripheral wall of the filter frame is arranged in line contact with the inner wall of the expansion portion; The filter frame is rotatably connected to the inner wall of the expansion portion via a rotating shaft, the rotating shaft is arranged perpendicular to the axis of the expansion portion, and the rotating shaft is arranged in the filter frame and the air filter along the diameter direction of the filter frame, both ends of the rotating shaft are rotatably connected to the expansion portion, and at least one end is arranged through the expansion portion; The expansion part is connected to the engine via a connecting part, one end of the connecting part is sleeved on the expansion part, and the other end is connected to the engine, both ends of the rotating shaft pass through the expansion part and the connecting part, two installation grooves are symmetrically provided on the outer periphery of the expansion part close to one end of the connecting part, four fastening grooves are evenly provided on the outer peripheral wall of the connecting part along the circumferential direction, two installation grooves are correspondingly provided with any two oppositely arranged fastening grooves, the ends of the installation grooves opposite to the fastening grooves are both open, the rotating shaft can slide along the length direction of the installation grooves and the fastening grooves, and a clamp is sleeved on the connecting part to compress the fastening grooves to press and fix the connecting part on the expansion part; Both ends of the rotating shaft are rotatably connected to the expansion part via a bearing, and the ends of the installation groove and the fastening groove away from their own open ends are respectively connected to each other and are provided with a first bearing hole and a second bearing hole, and when the connecting part is pressed and fixed on the expansion part, the bearing is clamped in the first bearing hole and the second bearing hole; Any end of the rotating shaft passes through the bearing, a motor is fixedly arranged on the connecting portion, and gears meshing with each other are respectively sleeved and fixed on the rotating shaft of the motor and the end of the rotating shaft passing through the bearing, and a humidity sensor is fixedly arranged on the outer periphery of the air inlet portion, the humidity sensor is electrically connected to the motor, and can control the motor to drive the filter frame to reciprocate between the first position and the second position through the rotating shaft; When the humidity sensor detects that the humidity of the external environment is low, the filter element is driven by the motor to rotate to the first position. When the humidity sensor detects that the humidity of the external environment is too high, the filter element is driven by the motor to rotate to the second position, so that the filter element can automatically switch its working state and position according to the external environment.

2. The waterproof air duct according to claim 1, characterized in that: A drainage bag is fixedly arranged on the drainage port, and a drainage portion is provided at the bottom end of the drainage bag. The drainage portion is a plate-shaped structure, and a drainage gap is provided on the drainage portion. The drainage gap connects the air inlet portion with the external environment.

3. The waterproof air duct according to claim 1, characterized in that: One end of the air intake portion connected to the outside air is an air inlet with an opening facing upward. The air intake portion is fixedly provided with an air bleed cap at the position of the air inlet. The upper end surface of the air bleed cap is closed and the lower end surface is open. The air inlet is located inside the air bleed cap, and a lip is fixedly provided on the lower end surface of the air bleed cap.

4. The waterproof air duct according to claim 3, characterized in that: A filter screen is fixedly arranged at the opening of the lower end surface of the air inlet cap. The filter screen is a wire mesh structure. The air inlet portion is arranged through the filter screen. The filter screen is fixedly connected to the outer peripheral wall of the air inlet portion.

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