Volute structure of smoke exhaust fan
By designing an asymmetric volute shell structure at the snail tongue of the hood smoke exhaust fan, and using the airflow to generate a new noise source, the problem of high noise in the existing hood is solved, the noise reduction effect is achieved, and the quietness of the use environment is improved.
Patent Information
- Application Number
- CN202422104134.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-28
- Publication Date
- 2025-06-27
- Estimated Expiration
- 2034-08-28
AI Technical Summary
When the existing hood smoke exhaust fan is started, the external oil smoke flow direction directly impacts the back plate of the wind collecting chamber, causing greater noise and affecting the quietness of the use environment.
A volute shell structure of a smoke exhaust fan is designed, and the volute tongue is connected by the edge lines and curves of the front cover plate and the rear cover plate to form an asymmetric design. The airflow generates a new noise source at the volute tongue to offset the original noise.
It effectively reduces the total noise of the hood, improves the user's kitchen environment, and makes it quieter and more comfortable.
Smart Images
Figure CN223035347U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of range hoods, and particularly to a volute structure of an exhaust fan. Background Art
[0002] In the prior art, when the exhaust fan of a range hood starts, when the external oil fume enters the air collecting cavity through the air suction port, its flow direction is towards the back plate of the air collecting cavity. The air flow entering through the air suction port will directly impact the back plate of the air collecting cavity, generating a relatively large noise and causing a noisy use environment. In the noise reduction technology, there is a principle of active noise cancellation, that is, "active noise reduction", which artificially forms a new sound source with the same amplitude but opposite phase as the noise source to cancel the original noise. Content of the Utility Model
[0003] The purpose of the utility model is to provide a volute structure of an exhaust fan, which is used to solve the above technical problems.
[0004] The utility model discloses a volute structure of an exhaust fan for a range hood, which includes a front cover plate, a rear cover plate, and a surrounding plate located between the two and connecting the two. At the volute tongue, the surrounding plate connects the front cover plate and the rear cover plate with a continuously smooth and transitional twisted surface; at the volute tongue, the edge line of the front cover plate is smoothly connected by a line segment AB, a curve BC, and a curve CD. The edge curve of the rear cover plate is smoothly connected by a line segment ab, a curve bc, and a curve cd. Among them, the length of the line segment AB is greater than the length of the line segment ab, the curves BC and bc respectively correspond to the front edge and the rear edge of the volute tongue, the length of the curve bc is less than the length of the curve BC, the length of the curve cd is greater than the length of the curve CD. When the rear cover plate projects onto the front cover plate, the projection of the line segment ab falls on the front cover plate, the projection of the curve bc falls on the front cover plate, the part of the projection of the curve cd close to the curve bc falls on the front cover plate, the part far from the curve bc coincides with the curve CD, and the projection of the edge line of the remaining part of the rear cover plate onto the front cover plate coincides with the edge line of other parts of the front cover plate.
[0005] According to an embodiment of the utility model, the radius of the circle where the curve BC is located is R1, and the radius of the circle where the curve bc is located is R2, and R1 > R2.
[0006] According to an embodiment of the utility model, the projection point of the center O1 of the circle where the curve bc is located on the front cover plate is O3, the center of the circle where the curve BC is located is O2, and the included angle α between the connection line O1O2 of the center O1 of the circle where the curve bc is located and the center O2 of the circle where the curve BC is located and the line O1O3 perpendicular to the front cover plate is 7° ≤ α ≤ 16°.
[0007] According to an embodiment of the utility model, the size of the radius R1 of the circle where the curve BC is located is 2 mm ≤ R1 ≤ 30 mm.
[0008] According to an embodiment of the present utility model, the radius R2 of the circle where the curve bc is located satisfies 2 mm ≤ R2 ≤ 30 mm.
[0009] According to an embodiment of the present utility model, the radius R1 of the circle where the curve BC is located is 20 mm, the radius R2 of the circle where the curve bc is located is 8.5 mm, and the included angle α is 8°.
[0010] According to an embodiment of the present utility model, the line segments AB and ab are oblique lines. The line segment AB is tangent to the curve BC at point B, and the line segment ab is tangent to the curve bc at point b.
[0011] According to an embodiment of the present utility model, the projection of the line segment ab is located on the extension line of the line segment AB.
[0012] According to an embodiment of the present utility model, the line segments AB and ab form an included angle θ with the vertical direction, where 30° ≤ θ ≤ 40°.
[0013] Compared with the prior art, the volute structure of the exhaust fan of the present utility model has the following advantages:
[0014] For the volute structure of the exhaust fan of the present utility model, the edge line of the front cover plate is smoothly connected by the line segment AB, the curve BC, and the curve CD at the volute tongue, and the edge curve of the rear cover plate is smoothly connected by the line segment ab, the curve bc, and the curve cd. Moreover, the length of the line segment AB is greater than the length of the line segment ab, the curves BC and bc respectively correspond to the leading edge and the trailing edge of the volute tongue, the length of the curve bc is less than the length of the curve BC, and the length of the curve cd is greater than the length of the curve CD. This makes the leading edge and the trailing edge of the volute tongue form an asymmetric design, and a new noise source is generated at the volute tongue. The new noise source can effectively cancel a part of the original noise of the range hood, thereby reducing the total noise of the range hood and making the kitchen environment of the user quieter and more comfortable. Description of the Drawings
[0015] Figure 1 It is a schematic structural diagram of the volute structure of the present utility model;
[0016] Figure 2 It is a schematic structural diagram of another perspective of the volute structure of the present utility model;
[0017] Figure 3 It is a side view of the volute structure of the present utility model;
[0018] Figure 4 It is a line schematic diagram of a partial contour of the volute structure of the present utility model;
[0019] Figure 5 It is a schematic diagram of the relationship between the curvature radii of the BC and bc segments of the present utility model.
[0020] In the figure: 1. Front cover plate, 2. Rear cover plate, 3. Enclosure plate.
[0021] The realization and advantages of the present utility model will be further described with reference to the embodiments and the accompanying drawings. Specific embodiments
[0022] The following will disclose multiple embodiments of the present utility model with the drawings. For the sake of clarity, many practical details will be described together in the following narration. However, it should be understood that these practical details are not used to limit the present utility model. That is to say, in some embodiments of the present utility model, these practical details are not necessary. In addition, for the purpose of simplifying the drawings, some conventional structures and components will be shown in a simple schematic manner in the drawings.
[0023] It should be noted that all directional indications (such as up, down, left, right, front, rear...) in the embodiments of the present utility model are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If this specific posture changes, then the directional indications will also change accordingly.
[0024] In addition, in the present utility model, descriptions such as "first" and "second" are only for descriptive purposes, and do not particularly refer to the order or sequence. Nor are they used to limit the present utility model. It is only used to distinguish components or operations described with the same technical terms, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the fact that those skilled in the art can implement them. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present utility model.
[0025] To further understand the content, features and effects of the present utility model, the following embodiments are cited and described in detail with the accompanying drawings as follows:
[0026] The present utility model discloses a volute structure of an exhaust fan for a range hood. Please refer to Figures 1 to 3, the volute structure includes a front cover plate 1, a rear cover plate 2, and a shroud 3 located between the two and connecting them. At the volute tongue, the shroud 3 connects the front cover plate 1 and the rear cover plate 2 with a continuously smooth and transitional twisted surface; at the volute tongue, the edge line of the front cover plate 1 is smoothly connected by a line segment AB, a curve BC, and a curve CD, and the edge curve of the rear cover plate 2 is smoothly connected by a line segment ab, a curve bc, and a curve cd. Among them, the length of the line segment AB is greater than the length of the line segment ab, the curves BC and bc respectively correspond to the leading edge and the trailing edge of the volute tongue, the length of the curve bc is less than the length of the curve BC, and the length of the curve cd is greater than the length of the curve CD. When the rear cover plate 2 projects onto the front cover plate 1, the projection of the line segment ab falls on the front cover plate 1, the projection of the curve bc falls on the front cover plate 1, the part of the projection of the curve cd close to the curve bc falls on the front cover plate 1, and the part far from the curve bc coincides with the curve CD. The projections of the edge lines of the remaining parts of the rear cover plate 2 onto the front cover plate 1 coincide with the edge lines of the other parts of the front cover plate 1.
[0027] Because in the existing range hoods, when the exhaust fan of the range hood starts, when the external cooking fumes enter the air collecting cavity through the air suction port, their flow direction is towards the back plate of the air collecting cavity, and the air flow entering through the air suction port will directly impact the back plate of the air collecting cavity, generating a relatively large noise. In this application, at the volute tongue, the edge line of the front cover plate 1 is smoothly connected by a line segment AB, a curve BC, and a curve CD, and the edge curve of the rear cover plate 2 is smoothly connected by a line segment ab, a curve bc, and a curve cd. Moreover, the length of the line segment AB is greater than the length of the line segment ab, the curves BC and bc respectively correspond to the leading edge and the trailing edge of the volute tongue, the length of the curve bc is less than the length of the curve BC, and the length of the curve cd is greater than the length of the curve CD. An asymmetric design is formed at the leading edge and the trailing edge of the volute tongue, and a new noise source is generated by the air flow at the volute tongue. The new noise source can effectively cancel a part of the original noise of the range hood, thereby reducing the total noise of the range hood and making the kitchen environment of the user quieter and more comfortable.
[0028] In the volute structure of the exhaust fan of the present utility model, please refer to Figure 3 and Figure 5 , the radius of the circle where the curve BC is located is R1, and the radius of the circle where the curve bc is located is R2, and R1 > R2. Optionally, the size of the radius R1 of the circle where the curve BC is located is 2 mm ≤ R1 ≤ 30 mm, preferably 10 mm ≤ R1 ≤ 25 mm, and more preferably 15 mm ≤ R1 ≤ 20 mm. Optionally, the size of the radius R2 of the circle where the curve bc is located is 2 mm ≤ R2 ≤ 30 mm, preferably 6 mm ≤ R2 ≤ 20 mm, and more preferably 8 mm ≤ R2 ≤ 15 mm.
[0029] After spectrum analysis, the noise of the smoke machine is a continuous spectrum sound with a considerable intensity in the range of 6.3 Hz to 20 kHz. In acoustics, "Continuous Spectrum Sound" refers to the sound whose frequency components change continuously within a certain range, rather than being composed of discrete frequencies. This kind of sound is usually composed of a mixture of sound waves of various frequencies, forming a continuous frequency distribution. In such a spectrum, the sound can be continuously distributed within a wide frequency range, forming a continuous curve, which is called a continuous spectrum.
[0030] It can be understood that in view of the characteristics of the continuous spectrum, we use continuously changing curvature (variable R) to reflect and form active noise cancellation. Different R values correspond to different curvatures, and the effects of reflecting sound waves are different. Therefore, if the value of R1 is too small, the noise generated by itself is very large, and the gain of the reflected part will be offset. So the value of R1 cannot be taken too small; because the volute tongue is at the air outlet of the centrifugal fan, the larger the R1, the larger the area blocking the air duct. If the noise is reduced but the air volume is seriously lost, the value of R1 cannot be taken too large. Similarly, the reason for setting the range of R2 can also refer to the above explanation.
[0031] In the volute structure of the exhaust fan of the present utility model, please refer to Figure 5 , the projection point of the center O1 of the circle where the curve bc is located on the front cover plate 1 is O3, the center of the circle where the curve BC is located is O2, and the included angle α between the connection line O1O2 of the center O1 of the circle where the curve bc is located and the center O2 of the circle where the curve BC is located and the line O1O3 perpendicular to the front cover plate 1 is 7° ≤ α ≤ 16°, preferably 8° ≤ α ≤ 10°.
[0032] In view of the characteristics of the continuous spectrum, we use continuously changing curvature (variable R) and continuously changing length (the length formed by the sides with different inclination angles is continuously changing for each wavelength) to reflect and form active noise cancellation, and adjust and optimize the curvature R1, R2 and the included angle α to achieve the maximum total cancellation, so as to form the best noise reduction.
[0033] In the volute structure of the exhaust fan of the present utility model, please refer to Figure 5 , the radius R1 of the circle where the curve BC is located is 20 mm, the radius R2 of the circle where the curve bc is located is 8.5 mm, and the included angle α is 8°.
[0034] Regarding the characteristics of the continuous spectrum, we use continuously varying curvature (variable R) and continuously varying length (the lengths formed by the sides with different inclination angles are continuously varying for each wavelength) to reflect and form active noise cancellation. By adjusting and optimizing the curvature R1, R2 and the included angle α, the maximum total cancellation is achieved, thereby forming the best noise reduction. Different R values correspond to different curvatures, and the effects of reflecting sound waves are different. At the same time, through multiple experimental verifications, when the radius R1 of the circle where the curve BC is located is 20 mm, the radius R2 of the circle where the curve bc is located is 8.5 mm, and the included angle α is 8°, the noise reduction is particularly obvious.
[0035] In the volute structure of the exhaust fan of the present utility model, please refer to Figure 5 and Figure 4 , the line segments AB and ab are oblique lines. The line segment AB is tangent to the curve BC at point B, and the line segment ab is tangent to the curve bc at point b. By setting AB and the line segment ab as oblique lines, the opening of the volute structure is set as a flared opening, which has a guiding effect and makes the air flow more smoothly.
[0036] In the volute structure of the exhaust fan of the present utility model, please refer to Figure 5 and Figure 4 , the projection of the line segment ab is located on the extension line of the line segment AB. In this way, the plane formed by the four points ABab is a plane.
[0037] In the volute structure of the exhaust fan of the present utility model, please refer to Figure 5 and Figure 4 , the line segments AB and ab form an included angle θ with the vertical direction, and 30° ≤ θ ≤ 40°. Generally, the opening of the volute structure is set as a rectangular opening, while in this application, the line segments AB and ab are inclined, and the included angle θ formed by the line segments AB and ab with the vertical direction ranges from 30° to 40°, achieving the optimal flared guiding effect.
[0038] The above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent replacements or improvements made within the spirit and principle of the present utility model shall be included in the protection scope of the present utility model.
Claims
1. A volute structure of a smoke exhaust fan, used in a smoke exhaust fan, characterized in that: The invention comprises a front cover plate (1), a rear cover plate (2) and a panel (3) located between the two and connecting the two. At the tongue of the worm, the panel (3) connects the front cover plate (1) and the rear cover plate (2) with a twisted surface with a continuous and smooth transition. At the tongue of the worm, the edge line of the front cover plate (1) is formed by a line segment AB, a curve BC and a curve CD connected by a smooth transition. The edge curve of the rear cover plate (2) is formed by a line segment ab, a curve bc and a curve cd connected by a smooth transition. The length of the line segment AB is greater than the length of the line segment ab. The curves BC and bc are respectively connected to At the leading edge and trailing edge of the volute tongue, the length of curve bc is less than the length of curve BC, the length of curve cd is greater than the length of curve CD, when the rear cover plate (2) is projected onto the front cover plate (1), the projection of line segment ab falls onto the front cover plate (1), the projection of curve bc falls onto the front cover plate (1), the projection of curve cd close to curve bc falls onto the front cover plate (1), and the projection of curve cd away from curve bc coincides with curve CD, and the projection of the edge line of the remaining part of the rear cover plate (2) onto the front cover plate (1) coincides with the edge line of the other part of the front cover plate (1).
2. The volute structure of the smoke exhaust fan according to claim 1, characterized in that: The radius of the circle where the curve BC lies is R1, the radius of the circle where the curve bc lies is R2, and R1>R2.
3. The volute structure of the smoke exhaust fan according to claim 2, characterized in that: The projection point O3 of the center O1 of the circle where the curve bc is located on the front cover plate (1), the center O2 of the circle where the curve BC is located, and the angle O1O2 between the line O1O2 connecting the center O1 of the circle where the curve bc is located and the center O2 of the circle where the curve BC is located and the line O1O3 perpendicular to the front cover plate (1) is α, 7°≤α≤16°.
4. The volute structure of the smoke exhaust fan according to claim 3, characterized in that: The radius R1 of the circle where the curve BC is located is 2 mm ≤ R1 ≤ 30 mm.
5. The volute structure of the smoke exhaust fan according to claim 3, characterized in that: The radius R2 of the circle where the curve bc is located is 2mm≤R2≤30mm.
6. The volute structure of the smoke exhaust fan according to claim 3, characterized in that: The radius R1 of the circle where the curve BC is located is 20 mm, the radius R2 of the circle where the curve bc is located is 8.5 mm, and the angle α is 8°.
7. The volute structure of the smoke exhaust fan according to claim 1, characterized in that: The line segment AB and the line segment ab are oblique lines, the line segment AB is tangent to the curve BC at point B, and the line segment ab is tangent to the curve bc at point b.
8. The volute structure of the smoke exhaust fan according to claim 7, characterized in that: The projection of the line segment ab is located on the extension line of the line segment AB.
9. The volute structure of the smoke exhaust fan according to claim 7, characterized in that: Line segment AB and line segment ab form an angle θ with the vertical direction, 30°≤θ≤40°.