Volute assembly of centrifugal fan, centrifugal fan and range hood

Abstract

The utility model discloses a volute assembly of centrifugal fan, centrifugal fan and range hood, the volute assembly of centrifugal fan comprises two cover plates that are arranged at interval, an annular wall is arranged between the two cover plates, the annular wall comprises a volute tongue; the annular wall further comprises a molded line adjusting assembly, the molded line adjusting assembly comprises a fixing shaft and an annular wall body capable of deforming, the fixing shaft is parallel to the axis of the centrifugal fan and is adjacent to the volute tongue in the circumferential direction, and the two ends of the fixing shaft are fixed to the cover plates at the corresponding positions respectively. The part of the ring wall main body is wound on the fixed shaft; the molded line adjusting assembly further comprises an electromagnet, the electromagnet is arranged on the outer side of the annular wall body, and the electromagnet attracts the annular wall body to move outwards in the radial direction when powered on so as to enlarge the molded line of the annular wall. The ring wall body maintains a tendency to minimize a ring wall profile.

Description

Technical Field

[0001] This utility model relates to power devices, and more particularly to a volute assembly of a centrifugal fan, a centrifugal fan using the volute assembly, and a range hood using the centrifugal fan. Background Technology

[0002] According to GB / T 17713-2022 "Range Hoods and Other Cooking Smoke Extraction Devices", the main noise evaluation indicators for range hoods include semi-anechoic chamber noise and operating noise. These parameters, as nominal indicators, are important bases for users to intuitively compare product performance, and noise also directly affects the user experience. Therefore, reducing the semi-anechoic chamber noise and operating noise of range hoods is crucial.

[0003] The fan system is the main structure affecting the noise of a range hood. Among the many methods to reduce the noise of a range hood, designing a reasonable volute profile is a common approach. Optimizing the volute profile can improve airflow and thus reduce eddy noise, as illustrated by the improved volute profiles disclosed in Chinese patents with application numbers 201110118687.5 and 201710798758.8.

[0004] However, the current volute profile design with the lowest noise level under semi-anechoic chamber conditions is not consistent with the profile design with the lowest noise level under full-duration noise conditions. That is, some volute profiles have low noise under semi-anechoic chamber conditions, but high noise under full-duration noise conditions, and vice versa.

[0005] Therefore, the volute profiles currently used in products typically require a trade-off between the semi-anechoic chamber noise and operating noise levels, and cannot simultaneously meet both requirements. Further improvements are needed. Utility Model Content

[0006] The first technical problem to be solved by this utility model is to address the shortcomings of the existing technology by providing a centrifugal fan volute assembly that can be adjusted in real time to meet the requirements of lower semi-anechoic chamber noise and operating noise.

[0007] The second technical problem to be solved by this utility model is to provide a centrifugal fan that uses the above-mentioned volute assembly.

[0008] The third technical problem to be solved by this utility model is to provide a range hood that uses the above-mentioned centrifugal fan.

[0009] The technical solution adopted by this utility model to solve the first technical problem mentioned above is as follows: a centrifugal fan volute assembly, comprising two cover plates arranged at intervals, and an annular wall provided between the two cover plates, wherein the annular wall includes a volute tongue; characterized in that:

[0010] The annular wall also includes a profile adjustment assembly, which includes a fixed shaft and a deformable annular wall body. The fixed shaft is parallel to the axis of the centrifugal fan and is adjacent to the volute tongue in the circumferential direction. Both ends of the fixed shaft are fixed to the cover plates at corresponding positions. A portion of the annular wall body is wound around the fixed shaft.

[0011] The profile adjustment assembly also includes an electromagnet, which is disposed on the outside of the ring wall body. When the electromagnet is energized, it attracts the ring wall body to move radially outward to increase the profile of the ring wall.

[0012] The main body of the ring wall maintains the trend of minimizing the ring wall profile.

[0013] By setting a deformable annular wall body, the annular wall body can be moved outward under the action of an electromagnet to increase the annular wall profile until the base circle radius of the spiral of the profile reaches its maximum, at which point the annular wall profile reaches its longest length, while still tending to make the profile shortest (the base circle radius of the spiral of the profile reaches its minimum). Thus, the profile can be changed according to actual working conditions, resulting in lower noise and operating noise in the semi-anechoic chamber. By winding the annular wall body part around a fixed shaft, the circumference can be changed accordingly when the profile changes, so as to avoid the change of the starting end position, which would cause the gap adjacent to the volute tongue to increase and cause pressure leakage, or the volute outlet and cover plate to be misaligned and cause pressure leakage, thus ensuring the normal operation of the centrifugal fan.

[0014] Furthermore, to facilitate the ring wall body maintaining the trend of minimizing the ring wall profile, the profile adjustment assembly also includes a spring-loaded spring. The end of the ring wall body is connected to a fixed shaft via the spring-loaded spring, thereby maintaining the trend of minimizing the ring wall profile.

[0015] Furthermore, to facilitate the fixing of the relative positions of the two cover plates, the volute assembly also includes a fastening plate disposed on the outer side of the ring wall body. The fastening plate is parallel to the extension direction of the fixed shaft, and both ends of the fastening plate are respectively fixed to the cover plates at corresponding positions. The electromagnet is fixed on the fastening plate.

[0016] Furthermore, to facilitate the fixing of the fastening plate and the cover plate, the two ends of the fastening plate are bent and welded to the cover plate at the corresponding positions.

[0017] Furthermore, to facilitate defining the relative positions of the annular wall body and the cover plate in the height direction of the volute and to avoid pressure leakage due to unevenness, a flange is formed at the end of the annular wall body away from the fixed axis. The flange is formed on opposite sides of the annular wall body. A limiting groove is formed on the side of each cover plate facing the inside of the volute assembly. The limiting groove extends along the width direction of the volute assembly. The flange is engaged in the limiting groove and can move linearly along the limiting groove.

[0018] To facilitate control of the inner steady-state position of the ring wall profile, each cover plate also has a limiting protrusion on the side facing the inside of the volute assembly, and the limiting protrusion is located on the radial inner side of the ring wall body.

[0019] To facilitate control of the steady-state position of the outer side of the ring wall profile, a limiting flange is also formed on the outer edge of each cover plate. Each limiting flange is formed by bending the edge of the cover plate toward another cover plate.

[0020] To facilitate the fixing of the fixed shaft and the cover plate, a base is formed on the outer side of each cover plate, and the end of the fixed shaft is fixed to the base.

[0021] The technical solution adopted by this utility model to solve the second technical problem mentioned above is: a centrifugal fan, characterized in that: it uses the volute assembly as described above.

[0022] The technical solution adopted by this utility model to solve the third technical problem mentioned above is: a range hood, characterized in that: it uses a centrifugal fan as described above.

[0023] Compared with the prior art, the advantages of this utility model are as follows: By setting a deformable annular wall body, the annular wall body can be moved outward under the action of an electromagnet to increase the annular wall profile until the base circle radius of the spiral line of the profile reaches its maximum, at which point the annular wall profile reaches its longest length, while still tending to make the profile shortest. Thus, the profile can be changed according to the actual working conditions, resulting in lower noise and operating noise in the semi-anechoic chamber. By winding the annular wall body part around a fixed shaft, the circumference can be changed accordingly when the profile changes, so as to avoid the change of the starting end position, which would lead to an increase in the gap adjacent to the volute tongue and pressure leakage, or the volute air outlet and cover plate position not being flush and causing pressure leakage, thus ensuring the normal operation of the centrifugal fan. By setting the cooperation of the limiting groove and flange, the limiting protrusion and the limiting flange, the steady-state position of the annular wall body can be controlled. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the volute assembly according to an embodiment of the present utility model;

[0025] Figure 2 This is a schematic diagram of the volute assembly according to an embodiment of the present utility model (and...). Figure 1 (Different perspectives);

[0026] Figure 3 for Figure 2 A magnified schematic diagram of part I;

[0027] Figure 4 This is an exploded structural diagram of the volute assembly according to an embodiment of the present utility model;

[0028] Figure 5 for Figure 4A magnified schematic diagram of part II;

[0029] Figure 6 This is a cross-sectional view of the volute assembly according to an embodiment of the present utility model;

[0030] Figure 7 for Figure 6 A magnified schematic diagram of part III;

[0031] Figure 8 This is a cross-sectional view (innermost state of the profile) of the volute assembly according to an embodiment of the present utility model;

[0032] Figure 9 This is a cross-sectional view (outermost state of the profile) of the volute assembly according to an embodiment of the present invention. Detailed Implementation

[0033] The embodiments of the present invention are described in detail below. Examples of the 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.

[0034] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description. They 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. Since the embodiments disclosed in this utility model can be arranged in different directions, these terms indicating direction are only for illustration and should not be regarded as limitations. For example, "upper" and "lower" are not necessarily limited to directions opposite to or consistent with the direction of gravity. In addition, features defined with "first" and "second" may explicitly or implicitly include one or more of such features.

[0035] See Figures 1 to 7 A volute assembly for a centrifugal fan, which is mainly used in range hoods, but can also be used in other applications requiring such a power unit.

[0036] The volute assembly includes two spaced-apart cover plates 1, with an annular wall between the two cover plates 1. The annular wall includes a volute tongue 21 and a profile adjustment assembly. The profile adjustment assembly includes a fixed shaft 221, a spring 222, and an annular wall body 223. The volute tongue 21 and the annular wall body 223 are independent of each other. The fixed shaft 221 is parallel to the axis of the centrifugal fan and is adjacent to the volute tongue 21 in the circumferential direction. Both ends of the fixed shaft 221 are fixed to the cover plates 1 at corresponding positions. To facilitate the fixing of the fixed shaft 221, a base 14 extends outward from the outer side of each cover plate 1, and the end of the fixed shaft 221 can be fixed to the base 14. Part of the annular wall body 223 is wound around the fixed shaft 221, and the wound portion is wound into a cylindrical shape. The end of the annular wall body 223 can be connected to the fixed shaft 221 through the spring 222. The unwound portions of the volute tongue 21 and the annular wall body 223 constitute a conventional annular wall, and the profile formed by their combination is the profile of the annular wall. By giving the annular wall a wound form, the problem of inconsistent circumference when the volute profile changes can be solved. The annular wall body 223 is made of a deformable material, such as a thin metal sheet.

[0037] The profile adjustment assembly also includes an electromagnet 225, disposed on the outer side (radially outer side) of the annular wall body 223. When energized, the electromagnet 225 attracts the annular wall body 223 to move radially outward. This radial outward movement refers to the outward movement of the portion of the annular wall body 223 not wound around the fixed shaft 221. As it moves outward, the number of turns around the fixed shaft 221 decreases, thereby increasing the circumference of the annular wall profile. The electromagnet 225 can be connected to the electrical box of the range hood for power supply. At least two electromagnets 225 are evenly spaced along the circumference of the annular wall, allowing for precise control of the various positions of the annular wall body 223 around its circumference.

[0038] The volute assembly also includes a fastening plate 3, which is disposed on the outside of the annular wall body 223. The fastening plate 3 is parallel to the extending direction of the fixed shaft 221. Both ends of the fastening plate 3 are bent and welded to the cover plate 1 at the corresponding positions, thereby fixing the volute assembly. The electromagnet 225 is fixed on the side of the fastening plate 3 facing the annular wall body 223.

[0039] At the end of the annular wall body 223 away from the fixed shaft 221, flanges 224 are formed on opposite sides (axial sides). Each cover plate 1 has a limiting groove 11 on the side facing the inside of the volute assembly. The limiting groove 11 extends along the width direction of the volute assembly, such as... Figure 6The flange 224 engages within the limiting groove 11, allowing for linear movement along the groove. Through the cooperation of the flange 224 and the limiting groove 11, the mobility of the annular wall body 223 is ensured, while maintaining the relative position (essentially flush) of this end of the annular wall body 223 with the cover plate 1. This prevents displacement of this end of the annular wall body 223 in the height direction of the volute assembly. The height direction refers to... Figure 6 The up and down directions are shown in the diagram.

[0040] Each cover plate 1 also has a limiting protrusion 12 formed on the side facing inwards from the volute assembly. The limiting protrusion 12 is located radially inwards from the annular wall body 223. Each cover plate 1 also has a limiting flange 13 formed on its outer edge, each flange being formed by bending the edge of the cover plate 1 towards another cover plate 1. The aforementioned annular wall body 223 is located between the limiting protrusion 12 and the limiting flange 13. The limiting protrusion 12 defines the limit position of the annular wall body 223 in radial inward contraction (inner limit), and the limiting flange 13 defines the limit position of the annular wall body 223 in radial outward expansion (outer limit). The positions of the limiting protrusion 12 and the limiting flange 13 can be obtained based on design testing, designed to achieve the lowest noise profile and the lowest operating noise profile for the semi-anechoic chamber.

[0041] Without the application of external force, the annular wall body 223 tends to maintain the shortest profile posture, that is, the annular wall body 223 can approach or adhere to the limiting protrusion 12. At this time, the number of turns of the annular wall body 223 reaches the maximum.

[0042] To optimize the flow control of the centrifugal fan and further reduce the noise levels in both operating modes (semi-anechoic chamber mode and full noise chamber mode) of the range hood when applied to it, the electromagnet 225 is energized and de-energized to switch to the lowest noise profile in the semi-anechoic chamber mode and to the lowest noise profile in the full noise chamber mode.

[0043] The logic for implementing the above-mentioned volute component is as follows:

[0044] 1) The profile with the lowest noise in the semi-anechoic chamber (denoted as profile A) and the profile with the lowest operating noise (denoted as profile B) were obtained through testing;

[0045] 2) Based on the above profile parameters, design a limiting protrusion 12 (assuming it corresponds to profile B) and a limiting flange 13 (assuming it corresponds to profile A) on the cover plate 1 of the volute assembly.

[0046] 3) Select a spring 222 with appropriate elasticity to ensure that, under conditions without electromagnetic force (applied by electromagnet 225), the unwound portion of the ring wall body 223 retracts tightly against the limiting protrusion 12 (the excess portion is wound onto the fixed shaft 221 under the action of the spring 222). At this time, the volute profile is close to profile B. See [reference needed]. Figure 8 ;

[0047] 4) Set appropriate electromagnet current and magnetic force to ensure that, under electromagnetic force (electromagnet 225 is energized), the unwound portion of the ring wall body 223 is tightly against the outer limiting flange 13. Since the profile circumference is relatively longer than profile B at this time, the number of turns of the ring wall winding 223 on the fixed shaft 221 is relatively reduced. At this time, the volute profile is close to profile A. (See...) Figure 9 ;

[0048] 5) Record the speed range of the range hood under working noise conditions (denoted as n1), and record the approximate speed range of the range hood in the semi-anechoic chamber noise meter (denoted as n2);

[0049] 6) When the range hood is actually working, if the actual rotation speed n is detected to be within the range of n1, the current of electromagnet 225 is cut off, and the volute profile is switched to profile B with lower working noise; if the actual rotation speed n is detected to be within the range of n2, the current of electromagnet 225 is turned on, and the volute profile is switched to profile A with lower semi-anechoic chamber noise.

Claims

1. A centrifugal fan casing assembly, comprising two spaced-apart cover plates (1), with an annular wall between the two cover plates (1), the annular wall including a volute tongue (21); characterized in that: The ring wall also includes a profile adjustment assembly, which includes a fixed shaft (221) and a deformable ring wall body (223). The fixed shaft (221) is parallel to the axis of the centrifugal fan and is adjacent to the volute tongue (21) in the circumferential direction. The two ends of the fixed shaft (221) are respectively fixed to the cover plate (1) at the corresponding positions. A part of the ring wall body (223) is wound around the fixed shaft (221). The profile adjustment assembly also includes an electromagnet (225), which is disposed on the outside of the ring wall body (223). When energized, the electromagnet (225) attracts the ring wall body (223) to move radially outward to increase the ring wall profile. The main body of the annular wall (223) maintains the tendency to minimize the annular wall profile.

2. The volute assembly of the centrifugal fan according to claim 1, characterized in that: The profile adjustment assembly also includes a spring (222), and the end of the ring wall body (223) is connected to the fixed shaft (221) through the spring (222) to maintain the trend of minimizing the ring wall profile.

3. The volute assembly of the centrifugal fan according to claim 1 or 2, characterized in that: The volute assembly also includes a fastening plate (3) disposed on the outside of the ring wall body (223). The fastening plate (3) is parallel to the extension direction of the fixed shaft (221). Both ends of the fastening plate (3) are fixed to the cover plate (1) at the corresponding positions. The electromagnet (225) is fixed on the fastening plate (3).

4. The volute assembly of the centrifugal fan according to claim 3, characterized in that: The two ends of the fastening piece (3) are bent and welded to the cover plate (1) at the corresponding positions.

5. The volute assembly of the centrifugal fan according to claim 1 or 2, characterized in that: The annular wall body (223) has a flange (224) formed at one end away from the fixed shaft (221). The flange (224) is formed on opposite sides of the annular wall body (223). Each cover plate (1) has a limiting groove (11) formed on one side facing the inside of the volute assembly. The limiting groove (11) extends along the width direction of the volute assembly. The flange (224) is engaged in the limiting groove (11) and can move linearly along the limiting groove (11).

6. The volute assembly of the centrifugal fan according to claim 1 or 2, characterized in that: Each cover plate (1) also has a limiting protrusion (12) on the side facing the inside of the volute assembly, the limiting protrusion (12) being located radially inside the annular wall body (223).

7. The volute assembly of the centrifugal fan according to claim 1 or 2, characterized in that: Each cover plate (1) also has a limiting flange (13) formed on its outer edge, and each limiting flange (13) is formed by bending the edge of the cover plate (1) toward another cover plate (1).

8. The volute assembly of the centrifugal fan according to claim 1 or 2, characterized in that: Each cover plate (1) extends outward to form a base (14), and the end of the fixed shaft (221) is fixed to the base (14).

9. A centrifugal fan, characterized in that: The application uses the volute assembly as described in any one of claims 1 to 8.

10. A range hood, characterized in that: The application includes the centrifugal fan as described in claim 9.

Images