Air intake ring and range hood

Abstract

This invention provides an air inlet ring and a range hood. The air inlet ring is applied to a centrifugal fan and includes an air inlet ring body and an air guide section. The air inlet ring body has a ring-shaped structure; the air guide section extends inward from the inner side of the air inlet ring body into the centrifugal fan, guiding the flowing air into the centrifugal fan under the action of the centrifugal fan. The air guide section includes multiple guide vanes arranged symmetrically about the center of the air inlet ring body; wherein the guide vanes are inclined arc-shaped structures, and the inclination direction of the guide vanes is consistent with the rotation direction of the centrifugal fan and is all in the positive direction, so that the air entering the centrifugal fan forms a spiral airflow. The air inlet ring body is connected to the fan housing of the centrifugal fan, and the guide vanes extend inclinedly from the air inlet ring body into the centrifugal fan, with the inclination direction of the guide vanes consistent with the rotation direction of the centrifugal fan, thereby improving the turbulent airflow state when fumes enter the impeller and uniformizing the airflow velocity.

Description

Technical Field

[0001] This invention relates to the field of kitchen appliance technology, and in particular to an air inlet ring and a range hood. Background Technology

[0002] As the core component of a range hood, the centrifugal fan plays a decisive role in the smoke extraction effect. The centrifugal fan includes a volute and an impeller set inside the volute. When the range hood is running, the impeller moves to create negative pressure inside the volute, and the airflow flows through the air inlet ring into the volute.

[0003] Existing centrifugal fans suffer from relatively complex internal air duct layouts due to factors such as the asymmetry of the volute profile design, the shape of the smoke collection structure, space limitations in the casing, and obstructions from other components. This results in inconsistent negative pressure distribution around the air inlet ring, leading to turbulent airflow and uneven velocity when fumes enter the impeller, which to some extent affects the smoke extraction performance of the centrifugal fan. Summary of the Invention

[0004] The purpose of this invention is to provide an air inlet ring, the main body of which is connected to the fan housing of a centrifugal fan. Guide vanes extend obliquely from the main body of the air inlet ring into the interior of the centrifugal fan, and the oblique direction of the guide vanes is consistent with the rotation direction of the centrifugal fan, thereby improving the turbulent airflow state when oil fumes enter the impeller and uniformizing the airflow speed.

[0005] To achieve the objectives of this invention, the following technical solution is adopted:

[0006] According to one aspect of the present invention, an air inlet ring is provided for use in a centrifugal fan. The air inlet ring includes an air inlet ring body and an air guide portion. The air inlet ring body has an annular structure; the air guide portion extends inward from the inner side of the air inlet ring body into the centrifugal fan, so as to guide the flowing air into the centrifugal fan under the action of the centrifugal fan. The air guide portion includes a plurality of guide vanes arranged symmetrically about the center of the air inlet ring body; wherein the guide vanes are inclined arc-shaped structures, and the inclination direction of the guide vanes is consistent with the rotation direction of the centrifugal fan and is all in the positive direction, so that the air entering the centrifugal fan forms a spiral airflow.

[0007] According to one embodiment of the present invention, the guide vane is flush with the position of the impeller of the centrifugal fan and has a first gap in the radial direction of the impeller.

[0008] According to one embodiment of the present invention, the bottom surface of the air inlet ring body and the top surface of the centrifugal fan impeller have a second gap in the axial direction of the impeller.

[0009] According to one embodiment of the present invention, the range of the outlet placement angle F1 of the guide vane is 0°≤F1≤90°, the range of the inlet placement angle F2 of the guide vane is 0°≤F2≤90°, and F1≤F2.

[0010] According to one embodiment of the present invention, when the blade inlet angle of the centrifugal fan is α, 0°≤F1≤α+25°.

[0011] According to one embodiment of the present invention, the placement angle F1 is in the range of α-10°≤F1≤α+15°.

[0012] According to one embodiment of the present invention, the guide vane is gradually twisted in a counterclockwise direction in the air flow direction, and the end of the guide vane away from the air inlet ring body forms an angle β with the axial direction of the centrifugal fan, and 0≤β≤90°.

[0013] According to another aspect of the present invention, a range hood is provided. The range hood includes the aforementioned air inlet ring and centrifugal fan. The centrifugal fan includes a fan housing, on which an air inlet is provided, and the air inlet ring body is disposed corresponding to the air inlet and connected to the fan housing.

[0014] According to one embodiment of the present invention, the centrifugal fan further includes an impeller coaxially arranged with the air inlet, and the outer wall of the impeller and the air inlet have a third gap in the radial direction of the impeller.

[0015] According to one embodiment of the present invention, the number of guide vanes is n. 导叶 The thickness of the guide vane is D. 导叶 The impeller has n blades. 叶片 The thickness of the impeller blades is D. 叶片 When 0.3D 叶片 ≤D 导叶 ≤10D 叶片 At that time, 0.5n 叶片 ≤n 导叶 ≤1.5n 叶片 .

[0016] One embodiment of the present invention has the following advantages or beneficial effects:

[0017] The air inlet ring of this invention is connected to the fan casing of a centrifugal fan. Guide vanes extend obliquely from the air inlet ring body into the centrifugal fan, with the guide vanes' inclination direction aligned with the centrifugal fan's rotation direction. This improves the turbulent airflow when oil fumes enter the impeller, resulting in a more uniform airflow velocity. The guide vanes, periodically distributed inside the air inlet ring body, form narrow airflow channels with a specific axial angle, providing a certain degree of sound insulation and noise reduction for the radiated sound field inside the centrifugal fan. Simultaneously, the pre-swirl effect reduces aerodynamic noise generated by impact. The impeller's inner diameter is greater than the diameter of the guide vane flush with the impeller, which is greater than the diameter of the guide vane. The minimum diameter is set such that the inner ring diameter of the inlet ring body is greater than or equal to the diameter of the inlet, ensuring that the inlet ring has sufficient air intake area and effectively reducing leakage losses of the centrifugal fan without reducing the effective working width of the impeller. A first gap and a second gap are set to ensure the impeller's rotational structural clearance in the axial and radial directions, respectively. By setting the inlet and outlet angles of the guide vanes and matching them with the inlet angle of the impeller blades, the airflow can flow smoothly from the guide vanes to the impeller, effectively reducing the impeller suction surface deflection and blade passage blockage caused by blade inlet impact losses without pre-rotation, thus avoiding a decrease in fan performance. Attached Figure Description

[0018] The above and other features and advantages of the present invention will become more apparent from a detailed description of exemplary embodiments thereof with reference to the accompanying drawings.

[0019] Figure 1 This is a perspective view illustrating an air inlet ring applied to a centrifugal fan according to an exemplary embodiment.

[0020] Figure 2 This is an exploded view illustrating an air inlet ring applied to a centrifugal fan according to an exemplary embodiment.

[0021] Figure 3 This is a cross-sectional view of an air inlet ring applied to a centrifugal fan according to an exemplary embodiment.

[0022] Figure 4 This is a schematic diagram of the structure of a guide vane of an air inlet ring according to an exemplary embodiment.

[0023] Figure 5 This is illustrated according to an exemplary embodiment. Figure 3 Enlarged view of point A in the middle.

[0024] The reference numerals in the attached figures are explained as follows:

[0025] 1. Main body of the air inlet ring; 2. Air guide section; 21. Guide vane; 3. First gap; 4. Second gap; 5. Centrifugal fan; 51. Fan casing; 511. Air inlet; 52. Impeller; 521. Outer wall; 522. Blade; 53. Motor. Detailed Implementation

[0026] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that the invention will be thorough and complete, and the concept of the exemplary embodiments will be fully conveyed to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore their detailed description will be omitted.

[0027] The terms “a,” “one,” “the,” and “the” are used to indicate the existence of one or more elements / components / etc.; the terms “including” and “having” are used to indicate an open-ended meaning of inclusion and that other elements / components / etc. may exist in addition to the listed elements / components / etc.

[0028] like Figures 1 to 5 As shown, Figure 1 A perspective view of an air inlet ring provided by the present invention applied to a centrifugal fan 5 is shown. Figure 2 An exploded view of an air inlet ring provided by the present invention applied to a centrifugal fan 5 is shown. Figure 3 A cross-sectional view of an air inlet ring provided by the present invention applied to a centrifugal fan 5 is shown. Figure 4 A schematic diagram of the structure of the guide vane 21 of an air inlet ring provided by the present invention is shown. Figure 5 This invention provides... Figure 3 Enlarged view of point A in the middle.

[0029] The air inlet ring of this invention is applied to a centrifugal fan 5. The air inlet ring includes an air inlet ring body 1 and an air guide 2. The air inlet ring body 1 has an annular structure. The air guide 2 extends inward from the inner side of the air inlet ring body 1 into the centrifugal fan 5, so as to guide the flowing air into the centrifugal fan 5 under the action of the centrifugal fan 5. The air guide 2 includes a plurality of guide vanes 21 arranged symmetrically about the center of the air inlet ring body 1. The guide vanes 21 are inclined arc-shaped structures, and the inclination direction of the guide vanes 21 is consistent with the rotation direction of the centrifugal fan 5 and is both in the positive direction, so that the air entering the centrifugal fan 5 forms a spiral airflow.

[0030] like Figure 1 and Figure 2As shown, the annular air inlet ring body 1 is fixed to the fan housing 51 of the centrifugal fan 5 and corresponds to the air inlet 511. The air inlet ring body 1 does not extend into the centrifugal fan 5. The air guide part 2 is set as multiple rotationally symmetrically arranged guide vanes 21. The guide vanes 21 extend obliquely from the inner side of the air inlet ring body 1 into the impeller 52. The oblique direction of each guide vane 21 is consistent with the rotation direction of the centrifugal fan 5 and is also in the positive direction, that is, rotating in the normal working direction. This forms a spiral pre-swirling airflow outside the impeller 52, so that the negative pressure distribution is uniform in the circumference of the air inlet ring. This improves the turbulent airflow state when oil fumes enter the impeller 52, and evens the airflow speed, thereby improving the performance of the centrifugal fan 5 and reducing the noise of the centrifugal fan 5.

[0031] In a preferred embodiment of the present invention, the guide vane 21 is flush with the position of the impeller 52 of the centrifugal fan 5 and has a first gap 3 in the radial direction of the impeller 52.

[0032] like Figure 3 and Figure 5 As shown, according to the requirements of the structural inspection specifications, when the impeller 52 rotates, the components close to the impeller 52 need to meet the minimum radial clearance along the radial direction of the impeller 52. The air inlet ring body 1 is located on the outside of the impeller 52, and the guide part extends from the air inlet ring body 1 to the inside of the impeller 52. Therefore, the guide vane 21 and the position flush with the impeller 52 are provided with a first gap 3 between them, and the first gap 3 meets the minimum radial clearance.

[0033] In a preferred embodiment of the present invention, the bottom surface of the air inlet ring body 1 and the top surface of the impeller 52 of the centrifugal fan 5 have a second gap 4 in the axial direction of the impeller 52.

[0034] like Figure 3 As shown, according to the requirements of the structural inspection specifications, when the impeller 52 rotates, the components close to the impeller 52 need to meet the minimum axial clearance along the axial direction of the impeller 52. Therefore, a second gap 4 is set between the bottom surface of the air inlet ring body 1 and the top surface of the impeller 52 of the centrifugal fan 5. The second gap 4 meets the minimum axial clearance.

[0035] In a preferred embodiment of the present invention, the outlet placement angle F1 of the guide vane 21 is in the range of 0°≤F1≤90°, the inlet placement angle F2 of the guide vane 21 is in the range of 0°≤F2≤90°, and F1≤F2.

[0036] like Figure 4As shown, at the connection between the air guide section 2 and the air inlet ring body 1, a circle is drawn with the center of the impeller 52. The outlet placement angle F1 is the angle between the tangent at the connection and the guide vane 21 at that point. At the point where the air guide section 2 and the impeller 52 are flush, a circle is drawn with the center of the impeller 52. The inlet placement angle F2 is the angle between the tangent at the flush point and the guide vane 21 at that point. Both the outlet placement angle F1 and the inlet placement angle F2 are acute angles. Setting F1≤F2 ensures that the flowing air can smoothly transition from the connection between the air guide section 2 and the air inlet ring body 1 to the point where the air guide section 2 and the impeller 52 are flush.

[0037] Furthermore, the circumferential projection of the guide vane 21 is a convex smooth transition curve, which can be composed of one or more of the following: circular arc, Bézier curve, logarithmic curve, quadratic function curve and cubic function curve. The convex direction is consistent with the rotation direction, thereby further smoothing the transition of the flowing air.

[0038] In a preferred embodiment of the present invention, when the inlet angle of the blade 522 of the centrifugal fan 5 is α, 0°≤F1≤α+25°.

[0039] like Figure 4 As shown, with the center of the impeller 52, a circle is drawn at the end of the blade 522 near the air guide 2. The inlet angle α of the blade 522 is the angle between the blade 522 and the tangent at that end. When 0°≤F1≤α+25°, the pre-swirling airflow generated by the flowing air at the guide vane 21 can flow smoothly to the inlet of the blade 522.

[0040] In a preferred embodiment of the present invention, the placement angle F1 is in the range of α-10°≤F1≤α+15°.

[0041] like Figure 4 As shown, the closer the angle of the airflow after pre-swirl by the guide vane 21 is to the inlet angle α of the blade 522, the smoother the airflow will enter the impeller 52. Setting α-10°≤F1≤α+15° can further improve the flow state of the airflow and enhance the smoke extraction performance of the centrifugal fan 5.

[0042] In a preferred embodiment of the present invention, the guide vane 21 is gradually twisted in the counterclockwise direction in the air flow direction, and the end of the guide vane 21 away from the air inlet ring body 1 forms an angle β with the axial direction of the centrifugal fan 5, and 0≤β≤90°.

[0043] like Figure 3 As shown, the guide vane 21 is twisted counterclockwise at one end near the center of the impeller 52, thus forming an angle β with the axial direction of the impeller 52. When β is an acute angle, the projected area of ​​the air inlet ring along the axial direction of the impeller 52 increases, and the coverage area on the air inlet side of the impeller 52 increases, which can reduce the risk of surge phenomenon at the air outlet of the fan under high back pressure.

[0044] The inlet ring body 1 of the present invention is connected to the fan housing 51 of the centrifugal fan 5. Guide vanes 21 extend obliquely from the inlet ring body 1 into the centrifugal fan 5, and the oblique direction of the guide vanes 21 is consistent with the rotation direction of the centrifugal fan 5, thereby improving the turbulent airflow state when oil fumes enter the impeller 52 and uniformizing the airflow velocity. The guide vanes 21, periodically distributed on the inner side of the inlet ring body 1, form a narrow airflow channel with a specific axial inclination angle, which has a certain degree of sound insulation and noise reduction effect on the radiated sound field inside the centrifugal fan 5. Simultaneously, the pre-swirl effect can reduce aerodynamic noise generated by impact. The inner diameter of the impeller 52 is greater than the diameter of the guide section 2 flush with the impeller 52, which is greater than the minimum diameter of the guide section 2. The inner ring diameter of the inlet ring body 1 is greater than or equal to the diameter of the inlet 511, ensuring that the inlet ring has sufficient air intake area and effectively reducing leakage loss of the centrifugal fan 5 without reducing the effective working width of the impeller 52; a first gap 3 and a second gap 4 are set to ensure the rotational structure clearance of the impeller 52 in the axial and radial directions respectively; by setting the inlet and outlet placement angles of the guide vane 21 and matching the inlet placement angle of the blade 522 of the impeller 52, the airflow can flow smoothly from the guide vane 21 to the impeller 52, effectively reducing the impeller 52 suction surface deflow and blade passage blockage caused by the inlet impact loss of the blade 522 without pre-rotation, thereby avoiding the resulting decrease in fan performance.

[0045] The range hood of this invention includes the aforementioned air inlet ring and centrifugal fan 5. The centrifugal fan 5 includes a fan housing 51, on which an air inlet 511 is provided, and the air inlet ring body 1 is disposed corresponding to the air inlet 511 and connected to the fan housing 51.

[0046] like Figure 1 and Figure 2 As shown, an air inlet 511 is opened on the side wall of the fan housing 51. The air inlet ring body 1 is fixed to the fan housing 51 by screws. The inner diameter of the air inlet ring body 1 is slightly larger than the diameter of the air inlet 511. The air inlet ring body 1 does not penetrate deep into the centrifugal fan 5, thereby increasing the effective air intake area of ​​the air inlet ring. By setting multiple guide vanes 21 to penetrate deep into the centrifugal fan 5, the leakage loss of the fan is effectively reduced without reducing the effective working width of the impeller 52. This makes the air intake pressure of the air inlet ring more uniform. The airflow direction of the air guide part 2 is consistent with the rotation direction of the impeller 52, which can improve the aerodynamic noise of the centrifugal fan 5.

[0047] In a preferred embodiment of the present invention, the centrifugal fan 5 further includes an impeller 52 coaxially arranged with the air inlet 511, and the outer side wall 521 of the impeller 52 and the air inlet 511 have a third gap in the radial direction of the impeller 52.

[0048] like Figure 1 and Figure 2 As shown, the centrifugal fan 5 also includes a motor 53, which drives the impeller 52 to rotate. The air inlet 511 is circular and is located on the side wall of the fan housing 51. The cross-section of the impeller 52 is also circular and is coaxial with the air inlet 511. There is a third gap between the top of the outer side wall 521 of the impeller 52 and the fan housing 51 at the air inlet 511. The third gap meets the minimum radial gap required by the structural inspection specifications.

[0049] In a preferred embodiment of the present invention, the number of guide vanes 21 is n. 导叶 The thickness of guide vane 21 is D. 导叶 The number of blades 522 in impeller 52 is n. 叶片 The thickness of the blades 522 of impeller 52 is D. 叶片 When 0.3D 叶片 ≤D 导叶 ≤10D 叶片 At that time, 0.5n 叶片 ≤n 导叶 ≤1.5n 叶片 .

[0050] When the inner diameter of the air inlet ring body 1 is equal to the diameter of the air inlet 511, the ratio of the axial projected area of ​​the air inlet ring to the area of ​​the entire air inlet 511 is the permeability. A low permeability is beneficial for noise reduction, but it will decrease the airflow of the centrifugal fan 5. An excessively high permeability will reduce the pre-swirl effect of the air guide 2, causing performance leakage in the centrifugal fan 5. To maximize the advantages of the air inlet ring while avoiding defects, the permeability should be between 30% and 90%. When 0.3D... 叶片 ≤D 导叶 ≤10D 叶片 At that time, 0.5n 叶片 ≤n 导叶 ≤1.5n 叶片 Furthermore, when D 导叶 =0.3D 叶片 When, n 导叶 =1.5n 叶片 When D 导叶 =10D 叶片 When, n 导叶 =0.5n 叶片 .

[0051] The range hood of the present invention includes an air inlet ring and a centrifugal fan 5. Due to the axial tilt angle of the guide vanes 21, the air inlet ring achieves a permeability between 30% and 90% by reasonably setting the number and thickness of the guide vanes 21. The area of ​​the air inlet ring projected along the axial direction is increased, and the coverage area on the air inlet side of the impeller 52 is increased, which can reduce the risk of surge phenomenon under high back pressure at the fan outlet.

[0052] In this embodiment of the invention, the term "multiple" refers to two or more, unless otherwise explicitly defined. The terms "install," "connect," and "fix" should be interpreted broadly. For example, "connect" can mean a fixed connection, a detachable connection, or an integral connection. Those skilled in the art can understand the specific meaning of the above terms in this embodiment of the invention based on the specific circumstances.

[0053] In the description of the embodiments of the present invention, it should be understood that the terms "upper" and "lower" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or unit 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 the embodiments of the present invention.

[0054] In the description of this specification, the terms "an embodiment," "a preferred embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0055] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. For those skilled in the art, the embodiments of the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of the present invention should be included within the protection scope of the embodiments of the present invention.

Claims

1. A range hood, characterized in that, include: Centrifugal fan (5), the centrifugal fan (5) includes a fan housing (51), and an air inlet (511) is provided on the fan housing (51); An air inlet ring, applied to a centrifugal fan (5), the air inlet ring comprising: An air inlet ring body (1) is a ring-shaped structure, and is disposed at the air inlet (511) and connected to the fan housing (51); and The air guide (2) extends from the inner side of the air inlet ring body (1) into the centrifugal fan (5) to guide the flowing air into the centrifugal fan (5) under the action of the centrifugal fan (5). The air guide (2) includes a plurality of guide vanes (21) arranged symmetrically about the center of the air inlet ring body (1). The guide vane (21) is an inclined arc-shaped structure. The inclination direction of the guide vane (21) is consistent with the rotation direction of the centrifugal fan (5) and both are in the forward direction, so that when the air enters the centrifugal fan (5), a spiral airflow is formed. The centrifugal fan (5) also includes an impeller (52) coaxially arranged with the air inlet (511), and the outer wall (521) of the impeller (52) and the air inlet (511) have a third gap in the radial direction of the impeller (52); The number of guide vanes (21) is n. 导叶 The thickness of the guide vane (21) is D. 导叶 The impeller (52) has n blades (522). 叶片 The thickness of the blade (522) is D. 叶片 When 0.3D 叶片 ≤D 导叶 ≤10D 叶片 At that time, 0.5n 叶片 ≤n 导叶 ≤1.5n 叶片 .

2. The range hood according to claim 1, characterized in that, The guide vane (21) is flush with the position of the impeller (52) of the centrifugal fan (5) and has a first gap (3) in the radial direction of the impeller (52).

3. The range hood according to claim 1, characterized in that, The bottom surface of the air inlet ring body (1) and the top surface of the impeller (52) of the centrifugal fan (5) have a second gap (4) in the axial direction of the impeller (52).

4. The range hood according to claim 1, characterized in that, The range of the outlet placement angle F1 of the guide vane (21) is 0°≤F1≤90°, and the range of the inlet placement angle F2 of the guide vane (21) is 0°≤F2≤90°, and F1≤F2.

5. The range hood according to claim 4, characterized in that, When the inlet angle of the blade (522) of the centrifugal fan (5) is α, 0°≤F1≤α+25°.

6. The range hood according to claim 5, characterized in that, The placement angle F1 is in the range of α-10°≤F1≤α+15°.

7. The range hood according to claim 1, characterized in that, The guide vane (21) is gradually twisted in the counterclockwise direction in the direction of air flow, and the end of the guide vane (21) away from the air inlet ring body (1) forms an angle β with the axis of the centrifugal fan (5), and 0≤β≤90°.

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