A volute structure and a range hood

Abstract

This invention discloses a volute structure and a range hood. The volute structure includes a volute body and a flow guiding device, the flow guiding device including a flow guiding and noise reduction plate. The volute body has a receiving cavity and an air outlet duct communicating with the receiving cavity. The volute body has an air inlet and an air outlet. The flow guiding and noise reduction plate is disposed on the side of the volute body away from the air outlet, forming a windward flow guiding surface. The first end face of the flow guiding and noise reduction plate is fixed to the volute body's volute casing, and the second end face is located on the tangential surface of the volute body from the air outlet to the air outlet duct, forming a noise reduction space. The projection of the first end face on the tangential surface is closer to the air outlet than the projection of the second end face on the tangential surface. Two protruding ribs are arranged on the flow guiding and noise reduction plate in the direction from the second end face to the first end face, the distance between the two ribs near the second end face being smaller than the distance near the first end face. This solves the problems of noise generation and poor flow guiding effect of centrifugal fans during use.

Description

Technical Field

[0001] This invention relates to the field of range hood technology, and more particularly to a volute structure and a range hood for absorbing oil. Background Technology

[0002] Range hoods typically use a volute casing to draw in, collect, and exhaust cooking fumes outdoors. Existing volute structures usually include a front cover, a rear cover, and surrounding panels. However, the surrounding panels are usually rectangular with equal width, while the front and rear covers are typically flat. This flatness results in poor airflow guidance, resistance and energy loss during airflow transmission, thus affecting intake efficiency and increasing fan noise. In other words, when airflow enters the volute from the impeller, the flat surface cannot form a continuous streamlined guide. The flow boundary layer on the cover surface develops unevenly, with a thin boundary layer near the center and a thickened boundary layer at the edges due to airflow stagnation, forming an axial secondary flow. This secondary flow collides with the mainstream airflow at the cover edge, causing not only energy loss but also backflow to the impeller inlet, creating an "airflow circulation" phenomenon that directly reduces intake efficiency. Because the distance between the two sides of the volute is equal, the shape of the volute is mismatched with the large flow rate, which easily leads to increased air separation within the volute, resulting in separation noise. According to the fluid dynamics theory of centrifugal fans, the airflow, after being thrown out of the impeller, needs to gradually expand along the volute channel to realize the conversion of velocity energy into pressure energy. However, the constant-width enclosure keeps the cross-sectional area of ​​the volute constant along the flow direction, forcibly compressing the airflow within the channel, causing a sudden increase in local velocity (up to 1.5 times the design velocity). The frictional resistance coefficient between the airflow and the inner wall of the enclosure increases by more than 30%, further aggravating energy loss. Another core problem brought about by the constant-width enclosure is the increased degree of air separation. Because the distance between the two sides of the volute is constant, under high flow conditions (such as when stir-frying, the smoke volume reaches 18m³), the separation becomes more pronounced. 3The velocity gradient of the airflow in the volute tongue region increases significantly (above a certain speed), with high velocity near the tongue and low velocity further away, creating a distinct velocity difference. This velocity difference disrupts the continuity of the airflow, causing large-area separation behind the tongue and forming vortex zones with diameters of 20-30 mm. These vortices continuously generate and collapse within the flow channel, producing broadband aerodynamic noise, with sound pressure levels in the 1000-2000 Hz band reaching over 65 dB, far exceeding the national standard limit of 55 dB. Furthermore, the flat front and rear covers also generate "pulse noise." When the airflow passes over the edge of the cover, a sudden change in the flow cross-section generates periodic pressure pulses. These pulses, at a frequency of 20-50 Hz, are transmitted to the volute shell, causing structural vibration and radiating low-frequency solid-borne sound. Although this low-frequency noise has a low sound pressure level (approximately 45-50 dB), it has strong penetrating power and can easily cause auditory fatigue in users. Insufficient diffusion in the volute prevents the airflow from converting kinetic energy into potential energy, leading to reduced centrifugal fan performance. The diffusion capacity of the volute directly determines the static pressure efficiency of the centrifugal fan, and the insufficient diffusion in existing structures has become a key constraint on fan performance. The diffusion angle (expansion angle of the flow channel section) of traditional equal-width enclosures is typically less than 5°, far below the ideal 8°-12° diffusion angle range, resulting in the airflow failing to achieve effective pressure boosting within the volute. Furthermore, traditional centrifugal fan inlets often employ simple guide cones or straight-tube structures, resulting in abrupt impacts when the airflow enters the impeller, leading to increased turbulent losses, significant boundary layer separation, and high-frequency aerodynamic noise. When airflow enters a straight-tube inlet at a speed of 15-20 m / s, the abrupt change in the flow cross-section between the inlet and the impeller inlet (typically with a cross-sectional contraction rate of 30%) prevents the airflow from smoothly turning along the streamline, causing direct collisions with the impeller blade inlet edges and resulting in localized impact losses. Furthermore, existing guide cones are mostly conical in shape, and their surface curvature cannot match the velocity distribution of the airflow, leading to boundary layer separation on the guide cone surface. The turbulence in the separation region can reach 5%-8% (ideally, it should be less than 3%). After the high-turbulence airflow enters the impeller, it interferes with the mainstream airflow on the blade surface, causing premature boundary layer separation on the blade surface. The separation area can reach 15%-20% of the blade surface area, further increasing energy loss. In addition, traditional guide structures cannot adapt to wide flow conditions. Existing noise reduction designs mostly use additional silencers, which increases system pressure loss. Reactive silencers cancel specific frequency noise through resonant cavities, but increase system pressure loss by 50-80 Pa; resistive silencers rely on sound-absorbing materials for noise reduction, but the airflow drag coefficient increases by 15%-20% due to material friction. The increase in system pressure loss forces the fan to increase its speed to maintain the exhaust volume, which in turn leads to a further increase in aerodynamic noise, creating a contradictory situation of "noise reduction - increased pressure loss - noise rebound". Summary of the Invention

[0003] This invention provides a volute structure and a range hood to solve the problems of noise generation and poor airflow performance of centrifugal fans during use.

[0004] According to one aspect of the present invention, a volute structure is provided, comprising: a volute body and a flow guiding device, wherein the flow guiding device includes a flow guiding and noise reduction plate; The volute body has a receiving cavity and an air outlet duct communicating with the receiving cavity, and the volute body has an air inlet and an air outlet. The airflow guide and noise reduction plate is disposed on the side of the volute body away from the air outlet, forming a windward airflow guide surface; the first end face of the airflow guide and noise reduction plate is fixed to the volute enclosure plate of the volute body, and the second end face is located on the tangential surface of the volute body from the air outlet to the air outlet duct, forming a noise reduction space. Wherein, the projection of the first end face on the cut surface is closer to the air outlet than the projection of the second end face on the cut surface; in the direction from the second end face to the first end face, two protruding ribs are arranged on the airflow guide and noise reduction plate, which protrude from the windward airflow guide surface, and the distance between the two protruding ribs near the second end face is smaller than the distance near the first end face.

[0005] Optionally, the projection of the flow-guiding and noise-reducing plate onto the vertical plane of the central axis of the volute body is arc-shaped.

[0006] Optionally, the volute body is provided with a first cover plate and a second cover plate, the first cover plate being located on the main air intake side of the volute body, and the second cover plate being located on the motor side of the volute body; The volute structure further includes: a first side plate, which is connected to the flow-guiding noise reduction plate to form a first connection point. The first side plate is also connected to the first cover plate to form a semi-enclosed noise reduction cavity for the noise reduction space. The first connection point is a rounded corner connection point.

[0007] Optionally, the volute structure further includes: a second side plate, which is connected to the flow-guiding noise reduction plate to form a second connection point, and the second side plate is also connected to the second cover plate to form a closed noise reduction cavity for the noise reduction space, wherein the second connection point is a rounded corner connection point.

[0008] Optionally, the flow guiding device further includes: a noise-reducing sound-absorbing body located within the noise-reducing space, wherein the shape of the noise-reducing sound-absorbing body is fitted into the shape of the inner wall of the noise-reducing space.

[0009] Optionally, the spacing between the two protruding ribs As the distance x from the first end face to the second end face changes, the following condition is met: ,in, The distance between the two protruding ribs near the first end face. The distance from the first end face to the second end face. , , The impeller diameter of the volute body; The height of the protruding rib in the direction perpendicular to the windward guide surface As the distance x from the first end face to the second end face changes, the following condition is met: ;in, The maximum height of the rib. .

[0010] Optionally, the air guiding device further includes: an air guiding structure located on the motor side of the volute body and disposed near the air outlet of the volute body; The airflow guiding structure has a first airflow guiding surface and a second airflow guiding surface. The first airflow guiding surface is inclined from the tangent towards the air outlet, and the second airflow guiding surface is inclined from the tangent towards the airflow guiding and noise reduction plate. The first airflow guiding surface and the second airflow guiding surface are connected to form a third connection point, which is a rounded corner connection point.

[0011] Optionally, the surface height of the flow guiding structure The equation: ,in, The fourth-order Bernstein basis function , , The impeller radius of the volute body is [missing information]. The impeller diameter of the volute body; Control Points coordinate , , The maximum height between the flow guiding structure and the cross-section. It is a natural number.

[0012] Optionally, the volute structure further includes: a back plate, the back plate being located at the cut surface, the back plate having a fixed part and an extension part, the air outlet duct extending to the air outlet's air outlet enclosure surface being fixedly connected to the fixed part, the extension part extending from the fixed part along the opposite direction of the air outlet's airflow, and the second end face of the airflow guide and noise reduction plate being fixed to the extension part; The back plate, the volute body, and the flow guiding device are integrally formed.

[0013] According to another aspect of the present invention, a range hood is provided, including a main unit and a smoke collection chamber, wherein the main unit includes the volute structure described in any embodiment of the present invention.

[0014] The technical solution of this invention, by setting a guide plate on the side of the volute body away from the air outlet to form a windward guide surface, and by setting two protruding ribs on the windward guide surface, with the distance between the two ribs near the second end face being smaller than the distance near the first end face, can guide the airflow entering the volute structure accordingly, allowing the airflow to flow towards the main airflow side of the volute body, avoiding the airflow being blocked at the volute enclosure and affecting the air intake efficiency. Furthermore, the setting of the windward guide surface and the two protruding ribs ensures that the airflow matches the shape of the windward guide surface, avoiding airflow separation noise. In addition, the setting of the windward guide surface allows the airflow to be guided in advance, preventing sudden impacts on the fan in the volute structure and reducing high-frequency aerodynamic noise. Moreover, the noise reduction space is formed by fixing the guide plate to the volute body, which further reduces noise. Therefore, this volute structure can achieve the effect of guiding and reducing noise.

[0015] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a first-view structural schematic diagram of the volute structure proposed according to an embodiment of the present invention; Figure 2 This is a second-view structural schematic diagram of the volute structure proposed according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the flow-guiding and noise-reducing plate with a volute structure proposed according to an embodiment of the present invention; Figure 4 This is a first-view structural schematic diagram of a volute structure proposed according to another embodiment of the present invention; Figure 5 This is a schematic diagram of the air intake on the main air intake side of the volute structure proposed according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the air intake on the motor side of the volute structure proposed according to an embodiment of the present invention; Figure 7 This is a first-view structural schematic diagram of a volute structure according to another embodiment of the present invention; Figure 8This is a second-view structural schematic diagram of the volute structure proposed according to yet another embodiment of the present invention; Figure 9 This is a schematic diagram of the structure of a range hood according to an embodiment of the present invention; Figure 10 This is an exploded structural diagram of the back panel and volute structure of the main unit of the range hood according to an embodiment of the present invention.

[0018] Reference numerals: 100, volute body; 101, accommodating cavity; 102, air outlet duct; 103, air inlet; 104, air outlet; 105, volute enclosure plate; 106, second cover plate; 107, first cover plate; 108, first side plate; 109, first connection point; 200. Flow guiding device; 201. Flow guiding and noise reduction plate; 201a. First end face; 201b. Second end face; 202. First protruding rib; 203. Second protruding rib; 204. Flow guiding structure; 204a. First flow guiding surface; 204b. Second flow guiding surface; 205. Third connection; 206. Back plate; 206a. Fixing part; 206b. Extension part; 207. Rectifier net; 208. Motor; 209. Fixing component; 300. Noise Reduction Space; 400. Main unit back panel; 500. Range hood; 501. Main unit; 502. Smoke collection chamber; PL, cross section; Y, airflow direction. Detailed Implementation

[0019] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0020] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0021] Figure 1 This is a first-view structural schematic diagram of the volute structure proposed according to an embodiment of the present invention. Figure 2 This is a second-view structural schematic diagram of the volute structure proposed according to an embodiment of the present invention; as shown. Figure 1 and Figure 2 As shown, the volute structure includes: a volute body 100 and a flow guiding device 200, the flow guiding device 200 including a flow guiding and noise reduction plate 201; The volute body 100 has a receiving cavity 101 and an air outlet duct 102 communicating with the receiving cavity 101. The volute body 100 has an air inlet 103 and an air outlet 104. The airflow guide and noise reduction plate 201 is set on the side of the volute body 100 away from the air outlet 104 to form an airflow guide surface; the first end face 201a of the airflow guide and noise reduction plate 201 is fixed to the volute enclosure plate 105 of the volute body 100, and the second end face 201b is located on the tangent PL of the volute body 100 from the air outlet 104 to the air outlet duct 102 to form a noise reduction space 300. Among them, the projection of the first end face 201a on the cross surface PL is closer to the air outlet 104 than the projection of the second end face 201b on the cross surface PL; in the direction from the second end face 201b to the first end face 201a, two protruding ribs (202, 203) are arranged on the airflow guide plate 201, which protrude from the windward airflow guide surface, and the distance between the two protruding ribs (202, 203) near the second end face 201b is smaller than the distance near the first end face 201a.

[0022] It should be noted that the volute body 100 includes a volute casing plate 105, a first cover plate 107 and a second cover plate 106, wherein the first cover plate 107 and the second cover plate 106 are arranged opposite to each other, the volute casing plate 105 is arranged around the first cover plate 107 and the second cover plate 106 and connects the first cover plate 107 and the second cover plate 106 to form a volute.

[0023] The volute body 100 is used in conjunction with a centrifugal fan, allowing airflow to enter through the air inlet 103, pass through the receiving cavity 101 and the air outlet duct 102, and then exit through the air outlet 104. In one embodiment, the volute body 100 can be used as the main unit of a range hood to exhaust cooking fumes. Due to the design of the main unit and the fume collection chamber, the airflow carrying cooking fumes generally flows freely. Figure 1 The arrow points in the direction of the main unit, where it enters and meets the volute body 100.

[0024] The airflow guide and noise reduction plate 201 is set on the side of the volute body 100 away from the air outlet 104, that is, on the windward side of the volute body 100. In this way, after the airflow enters the host, it can first encounter the airflow guide and noise reduction plate 201, so as to avoid the airflow forming disordered vortices and causing noise after encountering the enclosure of the volute body 100.

[0025] In addition, the airflow deflector and noise reduction plate 201 is provided with two protruding ribs (202, 203), namely the first protruding rib 202 and the second protruding rib 203. The two protruding ribs (202, 203) separate the airflow deflector and noise reduction plate 201 into three parts: the middle part and the two sides. The area of ​​the middle part increases and the width increases from the second end face 201b to the first end face 201a, while the area of ​​the two sides decreases and the width decreases from the second end face 201b to the first end face 201a. Furthermore, the protruding ribs protrude relative to the windward airflow guiding surface, and the first end face 201a is closer to the air outlet 104 than the second end face 201b. In this way, the airflow first encounters the second end face 201b after entering, causing the airflow to be forced to separate to both sides first, thus guiding the airflow.

[0026] Understandably, the closer to the first end face 201a, the larger and wider the area of ​​the middle section, thus allowing the airflow to be guided to the volute casing shroud 105 along with the middle section. Conversely, the smaller and narrower the areas of the two side sections, thus allowing the separated airflow to flow more smoothly to the sides of the volute casing body 100. This prevents the airflow guiding the volute casing shroud 105 from forming vortices with the airflow flowing to the sides of the volute casing body 100 at the first end face 201a, thus avoiding noise.

[0027] Furthermore, a cavity is formed between the airflow-guiding noise reduction plate 201 and the volute body 100. Airflow is almost entirely confined within this cavity, effectively isolating the airflow from directly impacting the volute body. Therefore, this cavity can also be referred to as the noise reduction space 300. In one embodiment, a sound-absorbing material can be placed within this cavity to further reduce noise in the volute structure.

[0028] It should also be noted that the airflow-guiding and noise-reducing plate 201 can be integrally formed with the volute body 100. Alternatively, it can be fixed to the volute body 100 by bolts, nuts, clips, adhesives, or welding.

[0029] Therefore, by setting the airflow guide and noise reduction plate 201, the airflow can be orderly guided and separated before entering the volute body 100, avoiding the problem of disordered airflow and noise caused by the airflow directly hitting the volute body 100.

[0030] Optionally, the projection of the flow-guiding and noise-reducing plate 201 onto the vertical plane of the central axis of the volute body 100 is arc-shaped.

[0031] The vertical plane of the central axis of the volute body 100 is parallel to either the first cover plate 107 or the second cover plate 106. For example... Figure 1 and Figure 2 As shown, the projection of the flow-guiding and noise-reducing plate 201 can be arc-shaped in the direction perpendicular to the first cover plate 107 or the second cover plate 106.

[0032] In other words, the airflow guide and noise reduction plate 201 forms an arc-shaped gradient in the direction from the second end face 201b to the first end face 201a. This allows the airflow to gradually climb when it encounters the airflow guide and noise reduction plate 201, and slowly be guided to the volute casing plate 105 of the volute body 100. This avoids direct impact between the airflow and the airflow guide and noise reduction plate 201, preventing airflow turbulence. Furthermore, the arc-shaped design of the airflow guide and noise reduction plate 201 further increases its area, thereby increasing the contact area between the airflow and the airflow guide and noise reduction plate 201, enabling better airflow guidance.

[0033] Optionally, continue to refer to Figure 1 and Figure 2 The volute body 100 is provided with a first cover plate 107 and a second cover plate 106. The first cover plate 107 is located on the main air intake side of the volute body 100, and the second cover plate 106 is located on the motor side of the volute body 100. The volute structure also includes: a first side plate 108, which is connected to the flow-guiding noise reduction plate 201 to form a first connection 109. The first side plate 108 is also connected to the first cover plate 107 to form a semi-enclosed noise reduction cavity in the noise reduction space 300. The first connection 109 is a rounded corner connection.

[0034] The first side plate 108 is connected to the airflow guide and noise reduction plate 201 with rounded corners, which can better guide the airflow to the main air intake side of the volute body 100. Furthermore, the first side plate 108 is connected to the first cover plate 107, making the noise reduction space 300 formed between the volute body 100 and the airflow guide and noise reduction plate 201 semi-enclosed. This further enclosure of the noise reduction space 300 increases the stability between the airflow guide and noise reduction plate 201 and the volute body 100, and also provides a certain degree of dust prevention for the noise reduction space 300.

[0035] In one embodiment, the volute body 100, the first side plate 108, the first connection 109, and the airflow-guiding and noise-reducing plate 201 can be integrally formed. Alternatively, they can be fixed by bonding, welding, snap-fitting, bolts, nuts, or other connection methods.

[0036] Optionally, continue to refer to Figure 1 and Figure 2 The volute structure also includes: a second side plate ( Figure 1 and Figure 2 (Not shown in the image), the second side plate is connected to the flow guide and noise reduction plate 201 to form a second connection point ( Figure 1 and Figure 2 (Not shown in the image), the second side plate is connected to the second cover plate 106 to form a closed noise reduction cavity for the noise reduction space, wherein the second connection is a rounded corner connection.

[0037] It is understood that the second side plate and the first side plate 108 are symmetrically arranged with respect to the flow-guiding noise reduction plate 201. The first side plate 108 is located between the first cover plate 107 and the flow-guiding noise reduction plate 201, and the second side plate is located between the second cover plate 106 and the flow-guiding noise reduction plate 201. The side of the first side plate 108 closest to the flow-guiding noise reduction plate 201 is connected to the flow-guiding noise reduction plate 201 through a rounded first connection 109, and the side of the second side plate closest to the flow-guiding noise reduction plate 201 is connected to the flow-guiding noise reduction plate 201 through a rounded second connection. The shape of the side of the first side plate 108 closest to the first cover plate 107 is adapted to the outer contour of the first cover plate 107. The shape of the side of the second side plate closest to the second cover plate is adapted to the outer contour of the second cover plate. Thus, through the arrangement of the first side plate 108, the first connection 109, the second side plate, the second connection, and the airflow-guiding noise reduction plate 201, a closed noise reduction space 300 is formed on the side of the volute body 100 away from the air outlet 104, further increasing the stability of the airflow-guiding noise reduction plate 201. The arrangement of the two rounded corner connections allows the airflow-guiding noise reduction plate 201 to better guide the airflow to both sides of the volute body 100. The arrangement of the first side plate 108 and the second side plate ensures that when the airflow flows towards the air outlet of the volute body 100, it will not form chaotic vortices in the noise reduction space 300, thus preventing noise generation.

[0038] In one embodiment, the first side plate 108, the first connection 109, the second side plate, the second connection, and the airflow-guiding and noise-reducing plate 201 can be integrally formed with the volute body 100, or they can be fixed by bonding, welding, snap-fitting, bolts and nuts, etc.

[0039] Optionally, the flow guiding device 200 further includes a noise reduction and sound absorption body located within the noise reduction space 300, wherein the shape of the noise reduction and sound absorption body is fitted into the shape of the inner wall within the noise reduction space 300.

[0040] It should be noted that the noise-absorbing material can be sound-absorbing cotton or other noise-reducing materials. Placed within the noise-reducing space 300, it can absorb some noise, further reducing noise levels. The noise-absorbing material can be interference-fitted with the noise-reducing space 300. After being integrally formed between the first side plate 108, the first connecting point 109, and the flow-guiding noise-reducing plate 201, the sound-absorbing cotton can fill the noise-reducing space 300. If a second side plate and a second connecting point are also provided, the flow-guiding noise-reducing plate 201 and the volute body 100 can be connected using snap-fit ​​or adhesive methods.

[0041] Among them, the noise reduction and sound absorption body can also absorb some of the noise from the centrifugal fan inside the volute body 100.

[0042] Optionally, the spacing between the two convex ribs (202, 203) As the distance x of the first end face 201a approaches the second end face 201b, it changes as follows: ,in, The distance between the two convex ribs (202, 203) near the first end face 201a is [missing information]. The distance from the first end face 201a to the second end face 201b. , , The impeller diameter is 100 mm for the volute body. The height of the ribs (202 / 203) in the direction perpendicular to the windward guide surface As the distance x of the first end face 201a approaches the second end face 201b, it changes as follows: ;in, The maximum height of the rib. .

[0043] It is understandable that a flow-guiding and noise-reducing plate 201 is provided at the lower part of the volute enclosure 105. The flow-guiding and noise-reducing plate 201 and the volute enclosure 105 form a cavity structure. On the main air intake side, the flow-guiding and noise-reducing plate 201 has a curved shape, and gradient micro-ribs (i.e. protruding ribs) are provided on the surface. Figure 3 This is a schematic diagram of the flow-guiding and noise-reducing plate with a volute structure proposed according to an embodiment of the present invention; Reference Figure 3 , Figure 3 for Figure 1 The left view of the middle flow-guided noise reduction plate is as follows: Figure 2 Right view of the middle flow guide noise reduction plate. The spacing between the two protruding ribs (202, 203) varies with the distance x of the first end face 201a from the second end face 201b: In other words, the distance λ between the two ribs (202, 203) decreases as the distance x between the first end face 201a and the second end face 201b increases. Furthermore, the height h of the ribs increases as the distance x between the first end face 201a and the second end face 201b increases.

[0044] Figure 3 A rectangular coordinate system is established with the direction of the distance λ between the two ribs as the horizontal axis, the direction from the first end face 201a to the second end face 201b as the vertical axis, and the height direction of the ribs as the depth axis. Equations can be obtained for the changes in the distance λ between the two ribs and the height h of the ribs with x. When the relationships between the distance λ between the two ribs and the height h of the ribs with x satisfy the above equations, a better flow guiding effect can be achieved.

[0045] Optionally, Figure 4 This is a first-view structural schematic diagram of a volute structure according to another embodiment of the present invention, with reference to... Figure 4 As shown, the flow guiding device 200 also includes a flow guiding structure 204, which is located on the motor side of the volute body 100 and is disposed near the air outlet 104 of the volute body 100. The airflow guiding structure 204 has a first airflow guiding surface 204a and a second airflow guiding surface 204b. The first airflow guiding surface 204a is inclined from the cut surface PL toward the air outlet 104, and the second airflow guiding surface 204b is inclined from the cut surface PL toward the airflow noise reduction plate 201. The first airflow guiding surface 204a and the second airflow guiding surface 204b are connected to form a third connection 205, which is a rounded corner connection.

[0046] Understandable Figure 5 This is a schematic diagram of the air intake on the main air intake side of the volute structure proposed in an embodiment of the present invention. Figure 6 This is a schematic diagram of the air intake on the motor side of the volute structure proposed in an embodiment of the present invention; combined with Figure 5 and Figure 6 As shown, when the airflow enters the volute structure, it is separated and guided to both sides of the volute body 100 by the airflow guide and noise reduction plate 201. The airflow guided to one side of the first cover plate 107 is drawn in by the main air intake side of the volute body 100 (e.g., Figure 5As shown), the airflow directed to one side of the second cover plate 106, being located on the motor side of the volute body 100, will form a vortex between the air outlet 104 and the second cover plate 106 of the volute body 100, generating noise or oil fume escape (such as...). Figure 6 (As shown). Furthermore, a flow guide structure 204 is provided near the air outlet 104 so that the airflow guided to one side of the second cover plate 106 can be reintroduced into the volute body 100 by the flow guide structure 204.

[0047] The first guide surface 204a and the second guide surface 204b can form a cavity, which is fastened to the second cover plate 106 and the cut surface PL. The first guide surface 204a can be an arc surface, the second guide surface 204b can be an arc surface, and the two are connected by a third connection point 205 with rounded corners, which can smoothly guide the airflow and better conform to the airflow flow mode.

[0048] Optionally, Figure 7 This is a first-view structural schematic diagram of a volute structure according to another embodiment of the present invention; Figure 8 This is a second-view structural schematic diagram of the volute structure proposed according to another embodiment of the present invention; Reference Figures 7 to 8 The volute structure also includes: a back plate 206, which is located at the cut surface PL. The back plate 206 has a fixing part 206a and an extension part 206b. The air outlet duct 102 extends to the air outlet enclosure surface of the air outlet 104 and is fixedly connected to the fixing part 206a. The extension part 206b extends from the fixing part 206a in the opposite direction of the air outlet 104. The second end face 201b of the airflow guide and noise reduction plate 201 is fixed to the extension part 206b. The back plate 206, the volute body 100 and the airflow guide device 200 are integrally formed.

[0049] The back plate 206 and the cut surface PL are located on the same plane. The back plate 206 is integrally formed with the volute body 100 and the flow guiding device 200, reducing installation steps and simplifying the manufacturing process. Because it is integrally formed, fewer installation parts are required, and noise caused by collisions between these installation parts due to vibration during fan operation is avoided. The extension 206b of the back plate 206, together with the volute body 100, the flow guiding noise reduction plate 201, the first side plate 108, the second side plate, the first connection 109, and the second connection, forms a noise reduction space 300. The width of the back plate 206 is designed based on the width of the volute casing shroud 105 of the volute body 100, and is generally larger than the width of the volute casing shroud 105. The length of the extension 206b in the back plate 206 depends on the angle between the flow guiding noise reduction plate 201 and the volute body 100. The larger the angle, the longer the length and the larger the noise reduction space; conversely, the smaller the angle, the shorter the length and the smaller the noise reduction space. The length of the fixing part 206a in the back plate 206 depends on the length of the air outlet duct 102 of the volute body 100.

[0050] Optionally, the surface height of the flow guide structure 204 The equation: ,in, The fourth-order Bernstein basis function , , The impeller radius of the volute body is... The impeller diameter is the diameter of the volute body. Control Points coordinate , , This is the maximum height between the flow guide structure and the cross-section. It is a natural number.

[0051] A polar coordinate system (r, θ) is established with the tangent point between the fixing part 206a of the back plate 206 and the volute body 100 as the origin and the direction pointing to the air outlet 104 as the radius. The various geometric parameters of the first guide surface 204a and the second guide surface 204b of the flow guiding structure 204 satisfy the above formula. The control points are the surface control points of the flow guiding structure 204. The surface of the flow guiding structure 204 conforms to the equation definition of a fourth-order Bézier curve and a hyperbolic tangent function. Boundary layer control and acoustic impedance matching are simultaneously achieved on the flow guiding structure 204 by setting a microgroove gradient distribution.

[0052] Therefore, in this embodiment, the parametrically designed multi-curvature composite flow-guiding noise reduction device adopts the fusion design of parametric asymmetric acceleration surface and acoustic structure to achieve aerodynamic-acoustic synergistic optimization.

[0053] According to another aspect of the present invention, a range hood is provided. Figure 9 This is a schematic diagram of the structure of a range hood according to an embodiment of the present invention; Figure 10 This is an exploded structural diagram of the back panel and volute structure of the main unit of the range hood according to an embodiment of the present invention, as shown below. Figure 9 and Figure 10 As shown, the range hood 500 includes a main unit 501 and a smoke collection chamber 502. The main unit 501 includes a volute structure according to any embodiment of the present invention.

[0054] The main unit 501 includes a main unit back plate 400, which is fixed together with the back plate 206 of the volute structure. The other housings of the main unit 501 are also fixed together with the main unit back plate 400. The main unit 501 is vertically arranged with the smoke collection chamber 502, and the oil fumes in the smoke collection chamber 502 can be absorbed by the main unit 501 and discharged from the air outlet.

[0055] Among them, such as Figure 8As shown, the main unit 501 includes a motor 208 and mounting brackets 209 for the motor 208. The motor 208 is located inside the volute structure and is fixed within the volute housing by multiple mounting brackets 209 surrounding the second cover plate 106. Figure 7 As shown, the main unit 501 is also provided with a rectifier mesh 207 and a detachable first cover plate 107 on the main air intake side of the first cover plate 107.

[0056] In other words, the main unit 501 is formed by integrated injection molding. The airflow guide and noise reduction plate 201 is located at the motor side of the air duct inlet, and the airflow guide structure 204 is on the volute housing. Airflow guide holes are designed below the volute housing of the air duct. The airflow guide and noise reduction plate 201 is connected to the rear plate of the air duct and the volute housing respectively. The main air inlet side of the airflow guide and noise reduction plate 201 has a curved design, while the motor side has an open design, forming a cavity structure with the volute housing. Sound-absorbing cotton material is placed in the cavity for noise reduction.

[0057] The overall structure of the range hood includes a main unit 501 and a smoke collection chamber 502. The duct structure includes a front volute panel rectifier mesh 207. The front volute panel (first cover plate 107) is made of sheet metal and is fixed to the duct structure with screws. The rectifier mesh 207 is installed outside the front volute panel. This range hood 500 can achieve the aforementioned claimed airflow guiding and noise reduction effects.

[0058] The technical solution of this invention, by setting a guide plate on the side of the volute body away from the air outlet to form a windward guide surface, and by setting two protruding ribs on the windward guide surface, with the distance between the two ribs near the second end face being smaller than the distance near the first end face, can guide the airflow entering the volute structure accordingly, allowing the airflow to flow towards the main airflow side of the volute body, avoiding the airflow being blocked at the volute enclosure and affecting the air intake efficiency. Furthermore, the setting of the windward guide surface and the two protruding ribs ensures that the airflow matches the shape of the windward guide surface, avoiding airflow separation noise. In addition, the setting of the windward guide surface allows the airflow to be guided in advance, preventing sudden impacts on the fan in the volute structure and reducing high-frequency aerodynamic noise. Moreover, the noise reduction space is formed by fixing the guide plate to the volute body, which further reduces noise. Therefore, this volute structure can achieve the effect of guiding and reducing noise.

[0059] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0060] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A volute structure, characterized in that, include: The volute body (100) and the flow guiding device (200) include a flow guiding and noise reduction plate (201); The volute body (100) is provided with a receiving cavity (101) and an air outlet duct (102) communicating with the receiving cavity (101). The volute body (100) is provided with an air inlet (103) and an air outlet (104). The airflow guide and noise reduction plate (201) is disposed on the side of the volute body (100) away from the air outlet (104) to form an airflow guide surface; the first end face (201a) of the airflow guide and noise reduction plate (201) is fixed to the volute enclosure plate (105) of the volute body (100), and the second end face (201b) is located on the cross-section of the volute body (100) from the air outlet (104) to the air outlet duct (102) to form a noise reduction space (300); Wherein, the projection of the first end face (201a) on the cut surface is closer to the air outlet (104) than the projection of the second end face (201b) on the cut surface; in the direction from the second end face (201b) to the first end face (201a), two protruding ribs are arranged on the airflow guide plate (201) that protrude from the windward airflow guide surface, and the distance between the two protruding ribs near the second end face (201b) is smaller than the distance near the first end face (201a).

2. The volute structure according to claim 1, characterized in that, The projection of the flow-guiding noise reduction plate (201) onto the vertical plane of the central axis of the volute body (100) is arc-shaped.

3. The volute structure according to claim 1, characterized in that, The volute body (100) is provided with a first cover plate (107) and a second cover plate (106). The first cover plate (107) is located on the main air intake side of the volute body (100), and the second cover plate (106) is located on the motor (208) side of the volute body (100). The volute structure further includes: a first side plate (108), the first side plate (108) being connected to the flow-guiding noise reduction plate (201) to form a first connection point (109), the first side plate (108) being connected to the first cover plate (107) to form a semi-closed noise reduction cavity in the noise reduction space (300), wherein the first connection point (109) is a rounded corner connection point.

4. The volute structure according to claim 3, characterized in that, The volute structure further includes: a second side plate, which is connected to the flow-guiding noise reduction plate (201) to form a second connection point. The second side plate is also connected to the second cover plate (106) to form a closed noise reduction cavity for the noise reduction space (300). The second connection point is a rounded corner connection point.

5. The volute structure according to claim 1, characterized in that, The flow guiding device (200) further includes a noise-reducing sound-absorbing body located within the noise-reducing space (300), wherein the shape of the noise-reducing sound-absorbing body is fitted into the shape of the inner wall within the noise-reducing space (300).

6. The volute structure according to claim 1, characterized in that, The spacing between the two protruding ribs As the distance x of the first end face (201a) approaches the second end face (201b) changes, the following condition is met: ,in, The distance between the two convex ribs near the first end face (201a) is the distance between them. The distance between the first end face (201a) and the second end face (201b) is the distance between them. , , The impeller diameter of the volute body (100); The height of the protruding rib in the direction perpendicular to the windward guide surface As the distance x of the first end face (201a) approaches the second end face (201b) changes, the following condition is met: ;in, The maximum height of the rib. .

7. The volute structure according to claim 1, characterized in that, The flow guiding device (200) further includes: a flow guiding structure (204), which is located on the motor (208) side of the volute body (100) and is disposed near the air outlet (104) of the volute body (100); The airflow guiding structure (204) has a first airflow guiding surface (204a) and a second airflow guiding surface (204b). The first airflow guiding surface (204a) is inclined from the tangent towards the air outlet (104), and the second airflow guiding surface (204b) is inclined from the tangent towards the airflow guiding noise reduction plate (201). The first airflow guiding surface (204a) and the second airflow guiding surface (204b) are connected to form a third connection (205), which is a rounded corner connection.

8. The volute structure according to claim 7, characterized in that, The curvature height of the flow guiding structure (204) The equation: ,in, The fourth-order Bernstein basis function , , The impeller radius of the volute body (100) is... The impeller diameter of the volute body (100); Control Points coordinate, , , The maximum height between the flow guiding structure (204) and the cross-section. It is a natural number.

9. The volute structure according to claim 7, characterized in that, Also includes: A back panel (206) is located at the cut surface. The back panel (206) has a fixing part (206a) and an extension part (206b). The air outlet duct (102) extends to the air outlet enclosure surface of the air outlet (104) and is fixedly connected to the fixing part (206a). The extension part (206b) extends from the fixing part (206a) in the opposite direction of the air outlet (104). The second end face (201b) of the airflow guide and noise reduction plate (201) is fixed to the extension part (206b). The back plate (206), the volute body (100), and the flow guiding device (200) are integrally formed.

10. A range hood (500), characterized in that, It includes a main unit (501) and a smoke collection chamber (502), wherein the main unit (501) includes the volute structure as described in any one of claims 1-9.

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