A fan damper for controlling air flow and a method of using the same

Abstract

The present invention relates to the field of damper technology, and more specifically, to a fan damper for controlling air flow and a method of using the same. The fan comprises a fan body and a damper housing, wherein two symmetrical damper control components are arranged inside the damper housing, and a pulling connection component is arranged between the damper control component and the inner wall of the damper housing, wherein one end of the two damper control components slides on the top of the inner cavity of the damper housing, and the other end generates a rebound force to fit the inner cavity side wall of the damper housing. When controlling the air flow, the present invention reduces the obstruction range of the airflow flow and improves the smoothness of the flow, and as a "triangle" shape is formed between the pulling connection component and the damper control component, it assists in bearing the impact of the airflow, thereby improving the service life, and at the same time quickly removes dust from the surface of the damper control component.

Description

Technical Field

[0001] The present invention relates to the technical field of dampers, and in particular to a fan damper for controlling air flow and a use method thereof. Background Art

[0002] "Ventilation" refers to the supply or extraction of air to a room or place, as well as the air circulation system in a room or place. At present, when ventilating a room or space where humans live or work, ventilation is mostly performed with the help of a ventilator. The air inlet of the ventilator is usually provided with a damper to control the air flow. For example, the prior art discloses a circular damper with an adjustable diameter for a ventilation system and a design method thereof, with patent number: CN105910253A. The circular damper with an adjustable diameter of the present invention can be used in a ventilation system with high requirements for air volume regulation. The staggered overlapping of multiple blades will not cause deformation and wear, and the long-term stable operation has good reliability.

[0003] However, the current damper has the following defects when in use:

[0004] First, the damper that can control the air flow usually needs to be connected to the air outlet connected to the fan with the help of a support when it is installed. Even if the damper is fully opened, the support is mostly located in the inner cavity of the air outlet, which not only blocks part of the airflow and affects the smoothness of the flow, but also increases the impurities carried by the airflow and is easy to adhere to the support, affecting the service life;

[0005] Secondly, when the damper is opened to allow air to enter the fan for ventilation, it is inconvenient to guide the direction of the airflow, resulting in the same flow rate of airflow in and out of the outside and the fan. If the flow rate of the outside airflow is fast, it is easy to cause discomfort in the indoor environment. If the airflow into the fan is slow, it affects the ventilation efficiency. In view of this, we propose a fan damper for controlling air flow and a method for using it. Summary of the invention

[0006] The object of the present invention is to provide a fan damper for controlling air flow and a method of using the same, so as to solve the problems raised in the above-mentioned background technology.

[0007] In order to solve the above technical problems, one of the objects of the present invention is to provide a fan damper for controlling air flow, comprising a fan body and a damper housing connected to the air inlet end of the fan body, two symmetrical damper control components are arranged inside the damper housing, and a pulling connection component is arranged between the damper control component and the inner wall of the damper housing, wherein:

[0008] One end of the two damper control components slides on the top of the damper housing inner cavity, and the other end generates a rebound force to fit the side wall of the damper housing inner cavity;

[0009] When the two damper control components gather inward to control the air flow, a flow cavity open to the outside is formed between the two damper control components for air flow to enter. At the same time, a "triangle" shape is formed between the pulling connection component and the damper control component to assist in bearing the impact of air flow and scrape against the surface of the damper control component.

[0010] Preferably, the damper control assembly at least comprises a baffle whose end slides in the inner cavity of the damper housing, a transmission member is provided at a rotating shaft near the end of the baffle, the transmission member slides in a groove opened at the top of the inner cavity of the damper housing, and a coil spring is provided between the inner cavity of the transmission member and the rotating shaft of the baffle;

[0011] The other end of the baffle is pressed against the side wall of the inner cavity of the damper housing by the resilience of the twisted spiral spring.

[0012] Preferably, a transmission screw is rotatably arranged in a groove opened at the top of the inner cavity of the damper housing, and the outer wall of the transmission screw is provided with two symmetrical threaded structures, which are respectively connected with the threads on the surfaces of the two transmission parts, and the end of the transmission screw is connected to a power source.

[0013] Preferably, the inner walls on both sides of the damper housing are provided with placement cavities, and the two placement cavities are adapted to the size of the two baffles in a parallel state.

[0014] Preferably, a limiting groove is provided at the top of the inner cavity of the damper housing and near the edge, and the pulling connection assembly at least comprises a pulling connecting rod and a limiting connecting rod whose ends slide and rotate inside the limiting groove;

[0015] The pulling link and the end of the limiting link are rotatably connected at the same axis, and the end of the pulling link and the baffle rotate and slide relative to each other;

[0016] The end of the limiting connecting rod is rotatably connected to the surface of the baffle plate close to the transmission screw rod.

[0017] Preferably, an elastic groove is provided on the surface of the baffle plate, and the pulling connection assembly also includes a through roller which slides in a sealing manner inside the elastic groove, and the through roller passes through the baffle plate surface and is fixedly connected to a brush plate, and the inner surface of the brush plate is provided with a plurality of bristles which fit the baffle plate surface, and the through roller is rotatably connected to the end of the pulling connecting rod through a rotating shaft structure.

[0018] Preferably, a cavity is formed on the outer wall of the baffle, the end of the limiting link rotates inside the cavity, and the rotating shaft connected between the pulling link and the limiting link at the same axis is located outside the cavity.

[0019] Preferably, a rolling contact piece is provided at the end slot of the baffle near the transmission screw, and the rolling contact piece includes a roller rotating in the slot, and a plurality of holes are provided on the outer wall of the roller, and a brush is slidably provided in each hole, and an elastic piece is fixedly connected between one end of the brush and the end of the inner cavity of the hole, and the other end fits into the filter screen at the connection between the fan body and the damper housing under the elastic force of the compression of the elastic piece.

[0020] A second object of the present invention is to provide a method for using a fan damper for controlling air flow, comprising the fan damper for controlling air flow as described in any one of the above, comprising the following steps:

[0021] S1. One end of the two damper control components slides on the top of the inner cavity of the damper housing to form a flow cavity that opens outward. The damper control components are tightly attached to the inner wall of the damper housing under the action of the rebound force, and a "triangle" shape is formed between the pulling connection component and the damper control component to assist in bearing the impact of the airflow;

[0022] S2. As the distance between the ends of the two damper control components decreases, the flow cavity size decreases, and vice versa, as the distance between the ends increases, the flow cavity size increases, and the air flow is controlled;

[0023] S3. When one end of the two damper control components are fitted together, the damper control components are tightly attached to the inner wall of the damper shell under the action of the rebound force, blocking the connection between the outside and the inside of the fan body. When one end of the damper control component slides to fit the side wall of the inner cavity of the damper shell, that is, when the two damper control components are in a parallel state, the size of the connection between the outside and the fan body is maximized.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. One end of the two damper control components slides on the top of the inner cavity of the damper housing to form an outward-opening flow cavity, so that the external airflow can directly enter the fan body through the flow cavity, reduce the obstruction range of the airflow, and improve the flow smoothness.

[0026] 2. When one end of the two damper control components are fitted together, the damper control components are tightly attached to the inner wall of the damper housing under the action of the rebound force, thereby blocking the connection between the outside and the inside of the fan body. At the same time, conversely, when one end of the damper control component slides to fit the side wall of the inner cavity of the damper housing, that is, when the two damper control components are in a parallel state, the size of the connection between the outside and the fan body is maximized, and the inlet and outlet flow rates of the airflow through the damper housing are consistent. As the distance between the ends of the two damper control components becomes smaller, the size of the flow cavity becomes smaller, and conversely, the larger the distance between the ends, the larger the size of the flow cavity, which is conducive to controlling the air flow.

[0027] 3. When the airflow enters the flow cavity, only the surface opposite to the damper control component directly contacts the airflow. As the pulling connection component and the damper control component form a "triangle" shape to assist in bearing the impact of the airflow, the damper control component is increased in terms of its impact strength and service life. If there are impurities in the airflow, they will only adhere to the surface of the damper control component. As the damper control component is adjusted, the pulling connection component is driven to brush against the surface of the damper control component, which is conducive to rapid dust removal.

[0028] 4. Two damper control components form a flow cavity that opens to the outside world for air flow to enter, so that the diameter of the air flow entering is larger and the air flow speed is relatively low. The diameter of the air flow discharging is smaller, and the air flow needs to pass through a smaller space. The speed will be significantly increased, which is conducive to avoiding the impact of the air flow speed on the external environment, and increasing the speed of air entering the fan body, thereby improving the efficiency of subsequent air purification. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the overall structure assembly of the present invention;

[0030] Figure 2 It is a cross-sectional view of the damper housing structure assembly of the present invention;

[0031] Figure 3 A demonstration diagram of partially opened airflow entering the present invention;

[0032] Figure 4 This is a demonstration diagram of the fully opened airflow entering the present invention;

[0033] Figure 5 It is a cross-sectional view of the damper housing structure of the present invention;

[0034] Figure 6 It is a structural schematic diagram of the air door control assembly and the transmission screw rod of the present invention;

[0035] Figure 7 It is a schematic diagram of the structural decomposition of the air door control assembly of the present invention;

[0036] Figure 8 For the present invention Figure 7 Schematic diagram of the structure at point A.

[0037] The meaning of each number in the figure is:

[0038] 100. Fan body;

[0039] 200, damper housing; 201, transmission screw; 202, limiting groove; 203, placement cavity;

[0040] 210. Air door control assembly;

[0041] 211, baffle; 212, cavity; 213, elastic slide; 214, transmission member; 215, coil spring;

[0042] 220. Pull the connection assembly;

[0043] 221, brush plate; 222, through roller; 223, pull connecting rod; 224, limit connecting rod;

[0044] 230, rolling contact;

[0045] 231. Roller; 232. Brush; 233. Elastic member. DETAILED DESCRIPTION

[0046] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Example

[0047] "Ventilation" refers to the supply or extraction of air into or from a room or place, as well as the air circulation system within a room or place. At present, when ventilating a room or space where humans live or work, ventilation fans are often used for ventilation. The air inlet of the ventilator is usually equipped with a damper to control the air flow, such as Figure 1-8 As shown, one of the purposes of the present invention is to provide a fan damper for controlling air flow, comprising a fan body 100 and a damper housing 200 connected to the air inlet end of the fan body 100, two symmetrical damper control components 210 are arranged inside the damper housing 200, and a pulling connection component 220 is arranged between the damper control component 210 and the inner wall of the damper housing 200, wherein:

[0048] One end of the two damper control components 210 slides on the top of the inner cavity of the damper housing 200, and the other end generates a rebound force to fit the inner cavity side wall of the damper housing 200;

[0049] When the two damper control components 210 gather inward to control the air flow, a flow cavity opened to the outside is formed between the two damper control components 210 for air flow to enter. At the same time, a "triangle" shape is formed between the pulling connection component 220 and the damper control component 210 to assist in bearing the impact of the air flow and scrape against the surface of the damper control component 210.

[0050] like Figure 1-Figure 4As shown, the present invention takes into account that the damper that can control the air flow at present usually needs to be connected to the air outlet connected to the fan with the help of a support member when installing. Although the damper is fully opened, the support member is mostly located in the inner cavity of the air outlet, which not only blocks part of the airflow and affects the smoothness of the flow, but also increases the impurities carried by the airflow and is easy to adhere to the support member, affecting the service life. Therefore, one end of the two damper control components 210 slides on the top of the inner cavity of the damper housing 200 to form an outwardly opened flow cavity, so that the external airflow passes through the flow cavity directly into the fan body 100, reducing the blocking range of the airflow flow and improving the smoothness of the flow;

[0051] When one end of the two damper control components 210 fits together, the damper control components 210 are tightly attached to the inner wall of the damper housing 200 under the action of the rebound force, blocking the connection between the outside and the inside of the fan body 100. At the same time, on the contrary, when one end of the damper control component 210 slides to fit the inner cavity side wall of the damper housing 200, that is, when the two damper control components 210 are in a parallel state, the size of the connection between the outside and the fan body 100 is maximized, and the inlet and outlet flow rates of the airflow through the damper housing 200 are consistent. As the distance between the ends of the two damper control components 210 is smaller, the flow cavity size is smaller, and conversely, the larger the distance between the ends, the larger the flow cavity size, which is conducive to controlling the air flow.

[0052] When the airflow enters the flow cavity, only the surface opposite to the damper control component 210 directly contacts the airflow. As the pulling connection component 220 and the damper control component 210 form a "triangle" shape to assist in bearing the impact of the airflow, the strength of the damper control component 210 in bearing the impact is increased, and the service life is improved. If there are impurities in the airflow, they will only adhere to the surface of the damper control component 210. As the damper control component 210 is regulated, the pulling connection component 220 is driven to brush against the surface of the damper control component 210, which is conducive to rapid dust removal.

[0053] Considering that when the damper is opened to allow air to enter the fan for ventilation, it is inconvenient to guide the direction of the airflow, resulting in the same flow rate of the airflow in and out of the outside and the fan. If the flow rate of the outside airflow is faster, it is easy to cause discomfort in the indoor environment. If the airflow entering the fan is slower, it affects the ventilation processing efficiency. Therefore, two damper control components 210 are used to form a flow cavity open to the outside for airflow to enter, so that the diameter of the airflow entering is larger, the airflow speed is relatively low, and the diameter of the airflow discharge is smaller. The airflow needs to pass through a smaller space, and the speed will be significantly increased, which is conducive to avoiding the impact of the airflow speed on the external environment, and increasing the speed of air entering the fan body 100, thereby improving the efficiency of subsequent air purification (heating, cooling, humidification or drying).

[0054] On the basis of the above, the specific structure needs to be disclosed in detail:

[0055] First, to realize that the air door control assembly 210 can control the air flow more conveniently and guide the incoming air, please refer to Figure 5-Figure 8 As shown, the damper control assembly 210 is further disclosed, so that the damper control assembly 210 at least includes a baffle 211 whose end slides in the inner cavity of the damper housing 200, and a transmission member 214 is provided at the rotating shaft near the end of the baffle 211, and the transmission member 214 slides in a groove opened at the top of the inner cavity of the damper housing 200, and a coil spring 215 is provided between the inner cavity of the transmission member 214 and the rotating shaft of the baffle 211;

[0056] Through the resilience of the twisted coil spring 215, the other end of the baffle 211 is pressed against the inner wall of the damper housing 200, and the transmission member 214 slides in the groove, driving the end of the baffle 211 to slide inward. At the same time, under the action of the resilience of the twisted coil spring 215, the baffle 211 is rotated to the other end to fit the inner wall of the damper housing 200, ensuring that the airflow can only enter from between the two baffles 211, and the airflow impacts the inclined surface of the baffle 211. When the airflow impacts the inclined surface, the impact force will be decomposed into two components: a normal force component perpendicular to the inclined surface and a tangential force component parallel to the inclined surface, thereby reducing the damage caused by the impact.

[0057] At the same time, the impurities carried by the airflow are only attached to the surface of the baffle 211, which is convenient for improving the cleaning efficiency later.

[0058] Specifically, in order to make it easier for the two baffles 211 to gather and diffuse inward at the same time, a transmission screw 201 is rotatably provided in a groove provided at the top of the inner cavity of the damper housing 200, and two symmetrical thread structures are provided on the outer wall of the transmission screw 201, which are respectively threadedly connected with the surfaces of the two transmission members 214, and a power source is connected to the end of the transmission screw 201, which is driven by the power source to rotate the transmission screw 201 in the groove, so that the two thread structures drive the two transmission members 214 to be threadedly transmitted to gather inward and diffuse outward, so that the closer the two baffles 211 are to the connecting port, the smaller the size is, which is conducive to more convenient air flow control;

[0059] As for the power source, it can be connected to the transmission screw 201 by means of the motor output shaft. The motor output shaft only needs to drive the transmission screw 201 to rotate. The power source only needs to provide the force for the transmission screw 201 to rotate. This is easy for people in this technical field to think of and will not be elaborated here.

[0060] Since the two baffles 211 are in a parallel state when they slide to the farthest distance, that is, when they are in contact with the inner side wall of the damper housing 200, in order to reduce the obstruction of the baffles 211 to the airflow entering the damper housing 200 and increase the size of the airflow entering, placement cavities 203 are opened on the inner walls on both sides of the damper housing 200. The two placement cavities 203 are adapted to the size of the two baffles 211 in a parallel state, so that the baffles 211 are adapted to be stored in the placement cavities 203, so that the damper housing 200 is connected with the inlet of the fan body 100 in a consistent size.

[0061] Then, to realize the pulling connection assembly 220 to improve the strength of the baffle 211 in sensing the impact and to ensure the auxiliary support as the baffle 211 rotates, please refer to Figure 3 , further discloses the structure of the pulling connection assembly 220, a limiting groove 202 is provided at the top of the inner cavity of the damper housing 200 and near the edge, and the pulling connection assembly 220 at least includes a pulling link 223 and a limiting link 224 whose ends slide and rotate inside the limiting groove 202;

[0062] The ends of the pulling link 223 and the limiting link 224 are rotatably connected at the same axis, and the end of the pulling link 223 and the baffle 211 rotate and slide relative to each other;

[0063] The end of the limiting link 224 is rotatably connected to the surface of the baffle 211 close to the transmission screw 201;

[0064] When the baffle 211 is transmitted and rotated along the transmission screw 201, the same axis between the pulling link 223 and the limiting link 224 is rotated and slid inside the limiting groove 202, the other end of the pulling link 223 slides on the outer wall of the baffle 211 and rotates, and the limiting link 224 rotates on the surface of the baffle 211, so that a "triangle" shape is formed between the three (the pulling link 223, the limiting link 224 and the baffle 211), so as to avoid the surface of the baffle 211 being in a suspended state and having limited ability to be impacted by airflow, so that the "triangle" structure shares the impact force and improves the service life.

[0065] Among them, since the surface of the baffle 211 is in direct contact with the airflow, impurities that flow with the airflow are easily attached to the surface of the baffle 211. When cleaning, the staff needs to go deep into the damper housing 200 to clean it, which is inconvenient to operate. Therefore, an elastic groove 213 is opened on the surface of the baffle 211, and the pulling connection component 220 also includes a through roller 222 that slides in the elastic groove 213 in a sealed manner. The through roller 222 penetrates to the surface of the baffle 211 and is fixedly connected to a brush plate 221. The inner surface of the brush plate 221 is provided with a plurality of The bristles are attached to the surface of the baffle 211, and the through roller 222 is rotatably connected to the end of the pulling link 223 through a rotating shaft structure, so that when the pulling link 223 is subjected to the rotating and sliding force of the baffle 211, the pulling link 223 and the through roller 222 rotate relatively, and at the same time, the through roller 222 slides on the surface of the baffle 211, which is equivalent to the sliding of the pulling link 223, ensuring the structural integrity while driving the brush plate 221 to scrape the impurities attached to the surface of the baffle 211, which is conducive to improving the cleaning effect and making it more convenient;

[0066] In order to realize the sealed sliding of the through roller 222 , an airbag may be provided on the inner wall of the elastic groove 213 , and only the surface of the airbag is squeezed and deformed at the position where the through roller 222 is located, while the airbags at other positions remain in close contact and sealed with each other.

[0067] Furthermore, in order to further ensure the compactness of the structure and prevent the pulling connection assembly 220 from occupying more space in the placement cavity 203 when the two baffles 211 are parallel, a cavity 212 is opened on the outer wall of the baffle 211, and the end of the limiting link 224 rotates inside the cavity 212. The rotating shaft connected at the same axis between the pulling link 223 and the limiting link 224 is located outside the cavity 212. This is beneficial for ensuring that the connection between the pulling connection assembly 220 and the baffle 211 is as compact as possible when the two baffles 211 are parallel, thereby reducing the occupied space. Example

[0068] When the current fan is in use, in order to reduce the entry of foreign matter into the fan body 100, a filter is usually provided at the connection between the fan body 100 and the damper housing 200 to reduce the entry of foreign matter. However, the filter increases the range of contact with dust, which makes it easy for dust to adhere and clog, thereby affecting the air flow effect. Therefore, a rolling contact member 230 is provided at the end slot of the baffle 211 close to the transmission screw 201. The rolling contact member 230 includes a roller 231 rotating in the slot. The outer wall of the roller 231 is provided with a plurality of holes. A brush 232 is slidably provided in each hole. An elastic member 233 is fixedly connected between one end of the brush 232 and the end of the inner cavity of the hole, and the other end is pressed against the filter at the connection between the fan body 100 and the damper housing 200 under the elastic force of the compression of the elastic member 233. When the baffle 211 is used to regulate the air flow, the roller 231 drives the brush 232 to rotate to clean the impurities on the surface of the filter, thereby improving the dredging effect.

[0069] A second object of the present invention is to provide a method for using a fan damper for controlling air flow, comprising any one of the above-mentioned fan dampers for controlling air flow, comprising the following steps:

[0070] S1. One end of the two damper control components 210 slides on the top of the inner cavity of the damper housing 200 to form a flow cavity that opens outward. The damper control components 210 are tightly attached to the inner wall of the damper housing 200 under the action of the rebound force, and a "triangle" shape is formed between the pulling connection component 220 and the damper control component 210 to assist in bearing the impact of airflow;

[0071] S2. As the distance between the ends of the two damper control components 210 decreases, the flow cavity size decreases, and conversely, as the distance between the ends increases, the flow cavity size increases, thereby controlling the air flow;

[0072] S3. When one end of the two damper control components 210 are fitted together, the damper control components 210 are tightly attached to the inner wall of the damper housing 200 under the action of the rebound force, thereby blocking the connection between the outside and the inside of the fan body 100. When one end of the damper control component 210 slides to fit the inner cavity side wall of the damper housing 200, that is, when the two damper control components 210 are in a parallel state, the size of the connection between the outside and the fan body 100 is maximized.

[0073] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and descriptions are only preferred examples of the present invention and are not intended to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A fan damper for controlling air flow, comprising a fan body (100) and a damper housing (200) connected to an air inlet end of the fan body (100), characterized in that: Two symmetrical damper control components (210) are arranged inside the damper housing (200), and a pulling connection component (220) is arranged between the damper control components (210) and the inner wall of the damper housing (200), wherein: One end of the two damper control components (210) slides on the top of the inner cavity of the damper housing (200), and the other end generates a rebound force to fit the inner cavity side wall of the damper housing (200); When the two damper control components (210) gather inward to control the air flow, a flow cavity that opens toward the outside is formed between the two damper control components (210) to allow air flow to enter. At the same time, a "triangle" shape is formed between the pulling connection component (220) and the damper control component (210) to assist in withstanding the impact of the air flow and to scrape against the surface of the damper control component (210).

2. The fan damper for controlling air flow according to claim 1, characterized in that: The damper control assembly (210) comprises at least a baffle (211) whose end slides in the inner cavity of the damper housing (200); a transmission member (214) is provided at a rotating shaft near the end of the baffle (211); the transmission member (214) slides in a groove provided at the top of the inner cavity of the damper housing (200); and a coil spring (215) is provided between the inner cavity of the transmission member (214) and the rotating shaft of the baffle (211); The other end of the baffle plate (211) is pressed against the inner cavity side wall of the damper housing (200) by the resilience of the twisted coil spring (215).

3. The fan damper for controlling air flow according to claim 2, characterized in that: A transmission screw (201) is rotatably disposed in a groove formed in the top of the inner cavity of the damper housing (200); the outer wall of the transmission screw (201) is provided with two symmetrical threaded structures, which are respectively threadably connected to the surfaces of the two transmission members (214); and the end of the transmission screw (201) is connected to a power source.

4. The fan damper for controlling air flow according to claim 3, characterized in that: The inner walls on both sides of the damper housing (200) are provided with placement cavities (203), and the two placement cavities (203) are adapted in size to the two baffles (211) in a parallel state.

5. The fan damper for controlling air flow according to claim 4, characterized in that: A limiting groove (202) is provided at the top of the inner cavity of the damper housing (200) and near the edge, and the pulling connection assembly (220) comprises at least a pulling connecting rod (223) and a limiting connecting rod (224) whose ends slide and rotate inside the limiting groove (202); The ends of the pulling link (223) and the limiting link (224) are rotatably connected at the same axis, and the end of the pulling link (223) and the baffle (211) are relatively rotatable and slidable. The end of the limiting connecting rod (224) is rotatably connected to the surface of the baffle (211) close to the transmission screw rod (201).

6. The fan damper for controlling air flow according to claim 5, characterized in that: An elastic groove (213) is provided on the surface of the baffle (211), and the pulling connection assembly (220) further comprises a through roller (222) which slides in a sealing manner inside the elastic groove (213), and the through roller (222) penetrates through the surface of the baffle (211) and is fixedly connected to a brush plate (221), and the inner surface of the brush plate (221) is provided with a plurality of bristles which are in contact with the surface of the baffle (211), and the through roller (222) is rotatably connected to the end of the pulling connecting rod (223) via a rotating shaft structure.

7. The fan damper for controlling air flow according to claim 6, characterized in that: The outer wall of the baffle (211) is provided with a cavity (212), the end of the limiting link (224) rotates inside the cavity (212), and the rotating shaft connected at the same axis between the pulling link (223) and the limiting link (224) is located outside the cavity (212).

8. The fan damper for controlling air flow according to claim 7, characterized in that: A rolling contact member (230) is provided at the end slot of the baffle (211) close to the transmission screw (201), and the rolling contact member (230) comprises a roller (231) that rotates in the end slot of the baffle (211), and a plurality of holes are provided on the outer wall of the roller (231), and a brush (232) is slidably provided in each hole, and an elastic member (233) is fixedly connected between one end of the brush (232) and the end of the inner cavity of the hole, and the other end of the brush (232) is attached to the filter screen at the connection between the fan body (100) and the damper housing (200) under the elastic force of the compression of the elastic member (233).

9. A method for using a fan damper for controlling air flow, applied to the fan damper for controlling air flow as claimed in any one of claims 1 to 8, characterized in that: The following steps are involved: S1. One end of the two damper control components (210) slides on the top of the inner cavity of the damper housing (200) to form a flow cavity that opens outwards. The damper control components (210) are tightly attached to the inner wall of the damper housing (200) under the action of the rebound force, and a "triangle" shape is formed between the pulling connection component (220) and the damper control component (210) to assist in bearing the impact of the airflow; S2, as the distance between the ends of the two air door control components (210) decreases, the size of the flow cavity decreases, and conversely, as the distance between the ends increases, the size of the flow cavity increases, thereby controlling the air flow; S3. When one end of the two damper control components (210) are fitted together, the damper control components (210) are tightly fitted against the inner wall of the damper housing (200) under the action of the rebound force, thereby blocking the connection between the outside and the inside of the fan body (100). When one end of the damper control component (210) slides to fit against the inner cavity side wall of the damper housing (200), that is, when the two damper control components (210) are in a parallel state, the dimension of the connection between the outside and the fan body (100) is maximized.

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