Fan volute and fan

Abstract

The utility model relates to the technical field of kitchen electric equipment, and particularly discloses a fan volute and a fan, the fan volute comprises a lower volute and an upper volute, the lower volute comprises a bottom plate and a lower inner side plate arranged on the bottom plate in a vortex mode; the upper volute comprises a top plate and an upper outer side plate arranged on the top plate in a vortex mode, the upper outer side plate and the lower inner side plate are arranged in an inserted mode so that a vortex air channel can be defined by the upper volute and the lower volute, and the upper outer side plate and the lower inner side plate are in sliding fit in the inserting direction that the upper outer side plate and the lower inner side plate are arranged in an inserted mode. When the fan provided with the fan volute works, the fan volute can adjust the radial size of the vortex air channel by adjusting the relative positions of the upper volute and the lower volute in the inserting direction so as to adjust performance parameters of the fan, a new adjusting mode is provided for performance adjustment of the fan, and the fan can adapt to more use scenes.

Description

Technical Field

[0001] This utility model relates to the field of kitchen appliance technology, and in particular to a fan casing and a fan. Background Technology

[0002] As times change, people are paying more and more attention to their quality of life. When cooking in the kitchen, the fumes produced contain many substances that are harmful to the human body. If you work in a room full of fumes for a long time, it can lead to many diseases. Therefore, range hoods are needed to filter the fumes, which puts more stringent requirements on them.

[0003] As the core component of a range hood, the fan affects its performance. A range hood mainly consists of a volute, impeller, collector, and motor. The motor drives the impeller to rotate, creating negative pressure inside the fan. This negative pressure draws gas into the impeller through the collector. Under the centrifugal effect of the rotating impeller, the gas passes through the blade channels and gains energy through the work done by the impeller's rotation. Finally, it is discharged from the fan through the guiding force of the volute and the diffusion effect of the diffuser. The volute, impeller, and collector, as the main structural components of the fan, directly determine its overall performance.

[0004] The main function of a fan casing is to concentrate and guide the gas leaving the impeller, and in this process, convert some of the dynamic pressure of the gas, which has gained energy from the impeller, into static pressure. When a fan operates in complex environments, its efficiency and flow rate need to be adjusted according to different conditions. However, the fan's performance parameters are determined when the casing is manufactured, and adjusting the fan's operating conditions can only be done by adjusting the motor speed. This limits the fan's performance adjustment and makes it unsuitable for complex working environments.

[0005] Therefore, a wind turbine casing is urgently needed to solve the above problems. Utility Model Content

[0006] The purpose of this utility model is to provide a fan casing and a fan to solve the problem in related technologies where the performance parameters of the fan are determined when the casing is manufactured, which limits the adjustment of the fan performance and makes it unable to meet the needs of complex working environments.

[0007] On the one hand, this utility model provides a fan volute, which includes:

[0008] The lower volute includes a base plate and a lower inner side plate on the base plate with a vortex.

[0009] The upper volute includes a top plate and an upper outer plate with a vortex disposed on the top plate. The upper outer plate and the lower inner plate are interlocked to form a vortex air passage. The upper outer plate and the lower inner plate slide together along the interlocking direction of the upper outer plate and the lower inner plate.

[0010] As a preferred technical solution for the wind turbine volute, the lower volute also includes a lower outer side plate, which is disposed on the bottom plate and located outside the lower inner side plate. The lower outer side plate and the lower inner side plate are spaced apart and surround to form a lower slot, and the upper outer side plate is inserted into the lower slot.

[0011] As a preferred technical solution for the wind turbine volute, the upper volute also includes an upper inner side plate, which is disposed on the top plate and located inside the upper outer side plate. The upper inner side plate and the upper outer side plate are spaced apart and surround an upper slot, and the lower inner side plate is inserted into the upper slot.

[0012] As a preferred technical solution for the wind turbine volute, along the insertion direction, the size of the lower inner side plate is less than or equal to the size of the lower outer side plate;

[0013] And / or, along the insertion direction, the size of the upper outer side plate is less than or equal to the size of the upper inner side plate.

[0014] As a preferred technical solution for the wind turbine volute, it also includes a first sealing strip. A first sealing strip is provided between the lower inner side plate and the upper outer side plate. The first sealing strip extends along the vortex direction of the lower inner side plate, and the lower inner side plate and the upper outer side plate clamp the first sealing strip.

[0015] And / or, it also includes a second sealing strip, wherein a second sealing strip is provided between the lower inner side plate and the upper inner side plate, the second sealing strip extends along the vortex direction of the lower inner side plate, and the lower inner side plate and the upper inner side plate clamp the second sealing strip;

[0016] And / or, it also includes a third sealing strip, which is provided between the upper outer side plate and the lower outer side plate. The third sealing strip extends along the spiral direction of the upper outer side plate, and the upper outer side plate and the lower outer side plate clamp the third sealing strip.

[0017] As a preferred technical solution for the wind turbine volute, it also includes an adjustment component, which is used to drive the upper volute and / or the lower volute to slide along the insertion direction, so that the upper volute and the lower volute include a first state and a second state. In the first state, the upper volute and the lower volute slide relative to each other along the insertion direction, and in the second state, the upper volute and the lower volute are relatively fixed.

[0018] As a preferred technical solution for the wind turbine volute, the adjustment component includes a telescopic rod, one end of which is fixed to the upper volute and the other end is fixed to the lower volute. The telescopic direction of the telescopic rod is consistent with the insertion direction.

[0019] As a preferred technical solution for the turbine volute, multiple telescopic rods are provided, and these multiple telescopic rods are spaced apart along the airflow direction of the vortex air passage.

[0020] As a preferred technical solution for the wind turbine volute, the upper volute also includes an upper support plate, and the lower volute also includes a lower support plate. The upper and lower support plates are spaced apart along the insertion direction. One end of the telescopic rod is fixedly connected to the upper support plate, and the other end of the telescopic rod is fixedly connected to the lower support plate.

[0021] On the other hand, this utility model provides a fan, including a check valve and a fan casing in any of the above-mentioned schemes. The check valve includes a valve body, a sliding plate, and a telescopic plate. The valve body is provided with an air inlet. The sliding plate is slidably disposed in the air inlet along the insertion direction and divides the air inlet into an independent connection port and an adjustment port. The fan casing is located at the outlet of the vortex air passage and is inserted into the connection port. The top plate or bottom plate is fixedly connected to the sliding plate. The telescopic plate closes the adjustment port and can extend and retract along the insertion direction.

[0022] The beneficial effects of this utility model are as follows:

[0023] This utility model provides a fan volute and a fan. The fan volute includes a lower volute and an upper volute. The lower volute includes a base plate and a lower inner side plate with a vortex disposed on the base plate. The upper volute includes a top plate and an upper outer side plate with a vortex disposed on the top plate. The upper outer side plate and the lower inner side plate are interlocked to form a vortex air passage. The upper outer side plate and the lower inner side plate are slidably fitted along the interlocking direction. When the fan equipped with this fan volute is working, the relative position of the upper and lower volutes along the interlocking direction can be adjusted to regulate the radial dimension of the vortex air passage, thereby adjusting the performance parameters of the fan. This configuration provides a new adjustment method for fan performance, enabling the fan to adapt to more application scenarios. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of the fan volute in an embodiment of this utility model;

[0025] Figure 2 This is a schematic diagram of the lower volute structure in an embodiment of the present invention. Figure 1 ;

[0026] Figure 3 This is a schematic diagram of the lower volute structure in an embodiment of the present invention. Figure 2 ;

[0027] Figure 4 This is a schematic diagram of the upper volute structure in an embodiment of the present invention;

[0028] Figure 5 This is a schematic diagram of the assembly plan of the lower volute and the upper volute in an embodiment of the present invention (only the lower inner side plate and the upper outer side plate are included);

[0029] Figure 6 This is a schematic diagram of the assembly plan of the lower volute and the upper volute in an embodiment of the present invention (only including the lower inner side plate, the lower outer side plate and the upper outer side plate);

[0030] Figure 7This is a schematic diagram of the assembly plan of the lower volute and the upper volute in an embodiment of the present invention (including the lower inner side plate, the lower outer side plate, the upper inner side plate, and the upper outer side plate);

[0031] Figure 8 This is a schematic diagram of the fan structure in an embodiment of the present invention. Figure 1 ;

[0032] Figure 9 This is a schematic diagram of the fan structure in an embodiment of the present invention. Figure 2 ;

[0033] Figure 10 This is a line graph showing the relationship between the width of the fan volute and the air volume of the fan in an embodiment of this utility model.

[0034] Figure 11 This is a line graph showing the relationship between the width of the fan volute and the efficiency of the fan in an embodiment of this utility model.

[0035] In the picture:

[0036] 1. Fan casing; 11. Lower casing; 111. Base plate; 112. Lower inner side plate; 113. Lower outer side plate; 114. Lower support plate;

[0037] 12. Upper volute; 121. Top plate; 122. Upper inner plate; 123. Upper outer plate; 124. Upper support plate;

[0038] 13. Adjustment components;

[0039] 2. Check valve; 21. Valve body; 22. Slide plate; 23. Telescopic plate;

[0040] 3. Impeller. Detailed Implementation

[0041] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0042] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions. Moreover, "above," "on top of," and "over" the first feature in relation to the second feature includes the first feature directly above and diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "under," and "below" the first feature in relation to the second feature includes the first feature directly below and diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0043] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0044] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0045] like Figures 1-4As shown, this embodiment provides a fan volute. The fan volute 1 includes a lower volute 11 and an upper volute 12. The lower volute 11 includes a base plate 111 and a lower inner side plate 112 vortexed on the base plate 111. The upper volute 12 includes a top plate 121 and an upper outer side plate 123 vortexed on the top plate 121. The upper outer side plate 123 and the lower inner side plate 112 are interlocked to form a vortex air passage. The upper outer side plate 123 and the lower inner side plate 112 slide in a sliding fit along the interlocking direction of the interlocking. When the fan equipped with this fan volute 1 is working, the relative position of the upper volute 12 and the lower volute 11 along the interlocking direction can be adjusted to adjust the radial dimension of the vortex air passage, thereby adjusting the performance parameters of the fan. This configuration provides a new adjustment method for the performance of the fan, enabling the fan to adapt to more application scenarios.

[0046] Optionally, the lower volute 11 further includes a lower outer side plate 113, which is disposed on the bottom plate 111 and located outside the lower inner side plate 112. The lower outer side plate 113 and the lower inner side plate 112 are spaced apart and form a lower slot, into which the upper outer side plate 123 is inserted. In this embodiment, on the one hand, the lower slot serves to guide and limit the upper volute 12, thereby allowing the upper volute 12 and the lower volute 11 to slide relative to each other only along the insertion direction; on the other hand, compared to only providing the lower inner side plate 112 and the upper outer side plate 123, the length of the air leakage channel formed by the lower inner side plate 112 and the upper outer side plate 123 is a, such as Figure 5 As shown by the dashed line; if the lower volute 11 is augmented with a lower outer plate 113, the length of the leakage channel formed between the lower inner plate 112, the upper outer plate 123, and the lower outer plate 113 is b, as shown. Figure 6 As shown by the dashed line; obviously a is less than b, therefore, the addition of the lower outer plate 113 to the lower volute 11 can improve the airtightness of the vortex air passage and thus prevent gas leakage.

[0047] Optionally, the upper volute 12 further includes an upper inner side plate 122, which is disposed on the top plate 121 and located inside the upper outer side plate 123. The upper inner side plate 122 and the upper outer side plate 123 are spaced apart and form an upper slot, and the lower inner side plate 112 is inserted into the upper slot. In this embodiment, on the one hand, the upper slot again serves to guide and limit the upper volute 12, thereby allowing the upper volute 12 and the lower volute 11 to slide relative to each other only along the insertion direction; on the other hand, after the lower inner side plate 112 is inserted into the upper slot and the upper outer side plate 123 is inserted into the lower slot, the length of the air leakage channel formed by the upper inner side plate 122, the lower inner side plate 112, the upper outer side plate 123 and the lower outer side plate 113 is c, such as Figure 7As shown by the dashed line, it is clear that b is less than c. Therefore, the lower volute 11 is augmented with a lower outer side plate 113, and the upper volute 12 is augmented with an upper inner side plate 122. This arrangement can further improve the airtightness of the vortex air passage, thereby preventing gas leakage.

[0048] Optionally, along the insertion direction, the size of the lower inner plate 112 is less than or equal to the size of the lower outer plate 113; and / or, along the insertion direction, the size of the upper outer plate 123 is less than or equal to the size of the upper inner plate 122. In this embodiment, along the insertion direction, the size of the lower inner plate 112 is smaller than the size of the lower outer plate 113, and the size of the upper outer plate 123 is smaller than the size of the upper inner plate 122. This arrangement ensures the airtightness of the vortex air passage while reducing the manufacturing cost of the fan casing 1.

[0049] In other embodiments, along the insertion direction, the size of the lower inner plate 112 is equal to the size of the lower outer plate 113, and the size of the upper outer plate 123 is equal to the size of the upper inner plate 122. This arrangement can further increase the length of the leakage channel and further improve the airtightness of the vortex air passage.

[0050] Optionally, the fan casing 1 includes a first sealing strip. The first sealing strip is provided between the lower inner side plate 112 and the upper outer side plate 123. The first sealing strip extends along the vortex direction of the lower inner side plate 112, and the lower inner side plate 112 and the upper outer side plate 123 clamp the first sealing strip. In this embodiment, the first sealing strip can improve the sealing effect between the lower inner side plate 112 and the upper outer side plate 123. Optionally, the first sealing strip is disposed on the upper outer side plate 123 or the lower inner side plate 112.

[0051] In other embodiments, the fan casing 1 includes only a second sealing strip. The second sealing strip is provided between the lower inner side plate 112 and the upper inner side plate 122, extending along the vortex direction of the lower inner side plate 112. The lower inner side plate 112 and the upper inner side plate 122 clamp the second sealing strip. In this embodiment, the second sealing strip can improve the sealing effect between the lower inner side plate 112 and the upper inner side plate 122. Optionally, the second sealing strip is disposed on either the lower inner side plate 112 or the upper inner side plate 122.

[0052] In other embodiments, the fan casing 1 includes only a third sealing strip. The third sealing strip is provided between the upper outer side plate 123 and the lower outer side plate 113, extending along the vortex direction of the upper outer side plate 123. The upper outer side plate 123 and the lower outer side plate 113 clamp the third sealing strip. In this embodiment, the third sealing strip can improve the sealing effect between the upper outer side plate 123 and the lower outer side plate 113. Optionally, the third sealing strip is disposed on the upper outer side plate 123 and the lower outer side plate 113.

[0053] In other embodiments, the fan casing 1 may also include a first sealing strip and a second sealing strip, or a first sealing strip and a third sealing strip, or a second sealing strip and a third sealing strip. Specifically, the positions of the first sealing strip, the second sealing strip and the third sealing strip are the same as those of the first sealing strip, the second sealing strip and the third sealing strip in the above embodiments.

[0054] In other embodiments, the fan casing 1 may also include a first sealing strip, a second sealing strip, and a third sealing strip. Specifically, the positions of the first sealing strip, the second sealing strip, and the third sealing strip are the same as those of the first sealing strip, the second sealing strip, and the third sealing strip in the above embodiments.

[0055] Optionally, the first sealing strip, the second sealing strip, and the third sealing strip are all high-temperature resistant rubber parts.

[0056] Optionally, the fan casing 1 further includes an adjustment component 13. The adjustment component 13 is used to drive the upper casing 12 and / or the lower casing 11 to slide along the insertion direction, so that the upper casing 12 and the lower casing 11 have a first state and a second state. In the first state, the upper casing 12 and the lower casing 11 slide relative to each other along the insertion direction, and in the second state, the upper casing 12 and the lower casing 11 are relatively fixed. In this embodiment, the adjustment component 13 can adjust the relative position of the upper casing 12 and the lower casing 11 along the insertion direction at any time, thereby facilitating the operator's operation and keeping the fan in optimal performance state in real time.

[0057] Optionally, the adjusting assembly 13 includes a telescopic rod, one end of which is fixed to the upper volute 12 and the other end to the lower volute 11. The telescopic rod extends and retracts in the same direction as the insertion direction. In this embodiment, since the telescopic rod extends and retracts along the insertion direction, the upper volute 12 and the lower volute 11 are in a first state of relative sliding when the telescopic rod extends and retracts, and in a second state of relative fixation when the telescopic rod stops working. Specifically, the telescopic rod can be one of a gear and rack structure, a lead screw and nut structure, a cylinder, a hydraulic cylinder, and a linear motor.

[0058] Optionally, multiple telescopic rods are provided, spaced apart along the airflow direction of the vortex air passage. In this embodiment, this arrangement allows the upper volute 12 and the lower volute 11 to slide stably along the insertion direction, preventing jamming. Specifically, four telescopic rods are provided, one located near the volute tongue, another located at the air outlet of the volute, and the remaining two positioned between the volute tongue and the air outlet of the volute along the airflow direction within the vortex air passage.

[0059] Optionally, the upper volute 12 further includes an upper support plate 124, and the lower volute 11 further includes a lower support plate 114. The upper support plate 124 and the lower support plate 114 are spaced apart along the insertion direction. One end of the telescopic rod is fixedly connected to the upper support plate 124, and the other end of the telescopic rod is fixedly connected to the lower support plate 114. In this embodiment, the upper support plate 124 is disposed on the outer peripheral wall of the top plate 121 and is coplanar with the top plate 121, and the lower support plate 114 is disposed on the outer peripheral wall of the bottom plate 111 and is coplanar with the bottom plate 111. The upper support plate 124 and the lower support plate 114 are used to provide a fixed position for the telescopic rod.

[0060] Preferably, the upper support plate 124 and the top plate 121 are integrally formed parts, and the lower support plate 114 and the bottom plate 111 are integrally formed parts.

[0061] like Figure 8 and Figure 9 As shown, this embodiment also provides a fan, including an impeller 3, a check valve 2, and the fan casing 1 described above. The check valve 2 includes a valve body 21, a sliding plate 22, and a telescopic plate 23. The valve body 21 is provided with an air inlet. The sliding plate 22 is slidably disposed within the air inlet along the insertion direction and divides the air inlet into an independent connection port and an adjustment port. The fan casing 1 is inserted into the connection port at the outlet of the vortex air passage. The top plate 121 or the bottom plate 111 is fixedly connected to the sliding plate 22. The telescopic plate 23 closes the adjustment port and can extend and retract along the insertion direction. In this embodiment, the impeller 3 is disposed in the middle of the fan casing 1 and is used to draw air into the vortex air passage. Taking the top plate 121 and the slide plate 22 as an example, when the upper volute 12 slides relative to the lower volute 11 along the insertion direction, the top plate 121 drives the slide plate 22 to slide together in the air inlet. Since the telescopic plate 23 can extend and retract along the insertion direction, the telescopic plate 23 can ensure that the adjustment port is closed. This ensures that the relative positions of the upper volute 12 and the lower volute 11 along the insertion direction can be adjusted normally, while preventing the gas flowing out of the vortex air passage from leaking out of the air inlet of the check valve 2.

[0062] Optionally, the telescopic plate 23 is made of an elastic material and is fixedly connected to the inner wall of the slide plate 22 and the air inlet. The slide plate 22 slides inside the air inlet, thereby stretching or compressing the telescopic plate 23.

[0063] Performance tests were conducted on a flue gas turbine equipped with the volute casing 1. Using the volute casing width as the independent variable, the changes in turbine displacement and efficiency were measured, and the results were as follows: Figure 10 and Figure 11 The line chart shown, Figure 10 The diagram shows that as the width of the fan casing 1 gradually increases, the air volume of the smoke fan gradually decreases; Figure 11The diagram shows that as the width of the fan casing 1 gradually increases, the efficiency of the range hood gradually decreases. Therefore, when this fan is installed on a range hood, in order to adapt the fan to different speed settings (strong, medium, and weak speed settings, etc.), not only can the motor power of the fan be adjusted, but also the width of the fan casing 1 (the distance between the lower casing 11 and the upper casing 12) can be adjusted, so that the fan can meet more working conditions.

[0064] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A fan casing, characterized in that, include: The lower volute (11) includes a base plate (111) and a lower inner side plate (112) vortexed on the base plate (111); The upper volute (12) includes a top plate (121) and an upper outer plate (123) vortexed on the top plate (121). The upper outer plate (123) and the lower inner plate (112) are interlocked to form a vortex air passage between the upper volute (12) and the lower volute (11). The upper outer plate (123) and the lower inner plate (112) are slidably engaged along the interlocking direction of the upper outer plate (123) and the lower inner plate (112).

2. The fan casing according to claim 1, characterized in that, The lower volute (11) also includes a lower outer side plate (113), which is disposed on the bottom plate (111) and located outside the lower inner side plate (112). The lower outer side plate (113) and the lower inner side plate (112) are spaced apart and surround a lower slot. The upper outer side plate (123) is inserted into the lower slot.

3. The fan casing according to claim 2, characterized in that, The upper volute (12) also includes an upper inner side plate (122), which is disposed on the top plate (121) and located inside the upper outer side plate (123). The upper inner side plate (122) and the upper outer side plate (123) are spaced apart and surround an upper slot. The lower inner side plate (112) is inserted into the upper slot.

4. The fan casing according to claim 3, characterized in that, Along the insertion direction, the size of the lower inner side plate (112) is less than or equal to the size of the lower outer side plate (113); And / or, along the insertion direction, the size of the upper outer side plate (123) is less than or equal to the size of the upper inner side plate (122).

5. The fan casing according to claim 3, characterized in that, It also includes a first sealing strip, which is provided between the lower inner side plate (112) and the upper outer side plate (123). The first sealing strip extends along the vortex direction of the lower inner side plate (112), and the lower inner side plate (112) and the upper outer side plate (123) clamp the first sealing strip. And / or, it also includes a second sealing strip, wherein the second sealing strip is provided between the lower inner side plate (112) and the upper inner side plate (122), the second sealing strip extends along the vortex direction of the lower inner side plate (112), and the lower inner side plate (112) and the upper inner side plate (122) clamp the second sealing strip; And / or, it also includes a third sealing strip, wherein the third sealing strip is provided between the upper outer side plate (123) and the lower outer side plate (113), the third sealing strip extends along the vortex direction of the upper outer side plate (123), and the upper outer side plate (123) and the lower outer side plate (113) clamp the third sealing strip.

6. The fan casing according to claim 1, characterized in that, It also includes an adjustment component (13) for driving the upper volute (12) and / or the lower volute (11) to slide along the insertion direction, so that the upper volute (12) and the lower volute (11) include a first state and a second state. In the first state, the upper volute (12) and the lower volute (11) slide relative to each other along the insertion direction, and in the second state, the upper volute (12) and the lower volute (11) are relatively fixed.

7. The fan casing according to claim 6, characterized in that, The adjustment assembly (13) includes a telescopic rod, one end of which is fixed to the upper volute (12) and the other end of which is fixed to the lower volute (11). The telescopic direction of the telescopic rod is consistent with the insertion direction.

8. The fan casing according to claim 7, characterized in that, Multiple telescopic rods are provided, and the multiple telescopic rods are spaced apart along the airflow direction of the vortex air passage.

9. The fan casing according to claim 7, characterized in that, The upper volute (12) further includes an upper support plate (124), and the lower volute (11) further includes a lower support plate (114). The upper support plate (124) and the lower support plate (114) are spaced apart along the insertion direction. One end of the telescopic rod is fixedly connected to the upper support plate (124), and the other end of the telescopic rod is fixedly connected to the lower support plate (114).

10. A fan, characterized in that, The device includes a check valve (2) and a fan volute as described in any one of claims 1-9. The check valve (2) includes a valve body (21), a sliding plate (22), and a telescopic plate (23). The valve body (21) is provided with an air inlet. The sliding plate (22) is slidably disposed in the air inlet along the insertion direction and divides the air inlet into an independent connection port and an adjustment port. The fan volute (1) is located at the outlet of the vortex air passage and inserted into the connection port. The top plate (121) or the bottom plate (111) is fixedly connected to the sliding plate (22). The telescopic plate (23) closes the adjustment port and is telescopic along the insertion direction.

Images