Check valve, cooking fume extractor and forming method of check valve

Abstract

The present application belongs to the technical field of household appliances, and particularly relates to a check valve, a range hood and a forming method of the check valve. The check valve comprises a valve seat body and a sound absorption layer. The valve seat body is injection molded, and a cavity is formed in at least a part of the circumferential side wall of the valve seat body. The sound absorption layer is located in the cavity and is injection molded and fixed to the inner wall of the cavity by fusion. The sound wave energy carried by the airflow can be effectively absorbed by the sound absorption layer when passing through the channel in the check valve, thereby fundamentally reducing the radiation noise of the air outlet. The valve seat body located in the outer layer and the sound absorption layer located in the inner layer are connected during the injection molding process. The liquid molten material forming the sound absorption layer can combine with the inner wall of the cavity to form a stable interlayer bonding interface, without the need for additional bonding or assembly processes, thereby fundamentally eliminating the risk of the noise reduction layer falling off and failing in the post-assembly scheme, while simplifying the production process and reducing the manufacturing cost.

Description

Technical Field

[0001] This invention relates to the field of household appliance technology, and in particular to a check valve, a range hood, and a method for molding the check valve. Background Technology

[0002] Range hoods play a crucial role in kitchen cooking by removing smoke and ensuring proper ventilation. Their operating noise directly impacts the user experience and comfort. As consumers increasingly demand quieter operation from home appliances, noise control of range hoods has become an important focus in product design and technological development.

[0003] The noise sources of a range hood are complex, mainly including mechanical noise generated by the fan operation, aerodynamic noise generated by airflow through the duct, and vortex noise generated by the interaction between the airflow and the check valve at the air outlet. Among these, the check valve is one of the most concentrated areas of airflow noise. After being accelerated by the fan, the fumes are exhausted from inside the range hood. When flowing through the check valve, due to changes in the duct cross-section and adjustments in airflow direction, the local airflow velocity increases sharply. The high-speed airflow impacts the inner wall of the valve seat and induces vortex shedding, generating broadband airflow noise. The airflow velocity at this location is the highest in the entire exhaust duct, thus its noise contribution is particularly prominent.

[0004] To address the aforementioned airflow noise problem, several solutions have been proposed in the existing technology, mainly including the following categories: One approach is to add sound-absorbing materials. Sound-absorbing materials such as cotton or polyurethane foam are adhered to the inner wall of the valve seat or the surface of the valve plate, utilizing the porous structure of the material to absorb sound waves. While this approach has some noise reduction effect, the sound-absorbing material is an independent additional component, requiring an extra bonding or fixing process after the valve body is formed. This not only increases assembly costs but also makes the material susceptible to adhesion failure and aging during long-term use due to oil fume corrosion and high temperatures, resulting in insufficient sustained noise reduction performance.

[0005] Secondly, there is the option of adding a resonant silencing structure. This involves installing a Helmholtz resonant cavity, a quarter-wavelength tube, or other silencing structures on the sidewall of the exhaust duct, utilizing the resonance and dissipation of sound waves at specific frequencies to achieve noise reduction. While this approach effectively suppresses noise in specific frequency bands, the resonant silencing structure is highly selective in frequency, limiting its adaptability to the common wideband airflow noise at range hood vents. Furthermore, the additional silencing structure occupies significant space, hindering product miniaturization and compact design.

[0006] In summary, existing technical solutions generally have the following shortcomings: the noise reduction functional layer is mostly a post-assembly structure, lacking integration with the valve body, resulting in complex manufacturing processes, increased costs, and poor long-term reliability; at the same time, existing solutions have failed to form an integrated composite structure that takes into account both structural strength and sound absorption and noise reduction functions for the key part of the air outlet valve seat, where airflow noise is most concentrated. Summary of the Invention

[0007] The purpose of this invention is to provide a check valve, a fume extraction device, and a method for molding the check valve, which can achieve noise reduction at the check valve without additional bonding or assembly processes, eliminate the risk of noise reduction layer falling off, and at the same time simplify the production process and reduce manufacturing costs.

[0008] To achieve this objective, the present invention adopts the following technical solution: A check valve, comprising: A valve seat body, wherein the valve seat body is injection molded, and at least a portion of the circumferential sidewall of the valve seat body has a cavity formed therein; A sound-absorbing layer is located inside the cavity, and the sound-absorbing layer is injection molded and fused to the inner wall of the cavity.

[0009] As an alternative to the aforementioned check valve, the strength of the valve seat body is greater than the strength of the sound-absorbing layer; And / or, the melting point of the valve seat body is higher than the melting point of the sound-absorbing layer; And / or, the density of the valve seat body is greater than the density of the sound-absorbing layer.

[0010] As an alternative to the aforementioned check valve, the sound-absorbing layer is a foamed layer.

[0011] As an alternative to the aforementioned check valve, the porosity of the sound-absorbing layer is 20%-60%; And / or, the sound-absorbing layer includes foam pores with a diameter of 0.1mm-2mm.

[0012] As an alternative to the aforementioned check valve, the thickness of the sound-absorbing layer is 50%-70% of the total wall thickness of the check valve.

[0013] As an alternative to the aforementioned check valve, the total wall thickness of the check valve is 4mm-6mm.

[0014] As an alternative to the aforementioned check valve, the valve seat body is injection molded from acrylonitrile-butadiene-styrene copolymer, polypropylene, or PC / ABS alloy.

[0015] As an alternative to the aforementioned check valve, the sound-absorbing layer is injection molded from micro-foamed polypropylene, polyester foam, or EPDM foam material.

[0016] A fume extraction device, comprising: Organism; A fan is disposed within the machine body, and the fan includes an air outlet; The aforementioned check valve has its valve seat body connected to the air outlet.

[0017] A method for molding a check valve, used to mold the aforementioned check valve, the method comprising: The valve seat body is injection molded from a first material, and a cavity is formed in at least the circumferential sidewall of the valve seat body; The cavity is used to form a molding cavity for the sound-absorbing layer. A second material is injected into the molding cavity to form the sound-absorbing layer. Part of the second material is fused to the inner wall of the cavity to form a fusion layer connecting the sound-absorbing layer and the valve seat body.

[0018] The beneficial effects of this invention are: The check valve provided by this invention achieves in-situ noise reduction by setting a sound-absorbing layer in the cavity of the side wall of the valve seat body. This means it reduces noise at the source of the noise, effectively absorbing the sound wave energy carried by the airflow as it passes through the internal channel of the check valve, thus reducing the radiated noise from the air outlet. The outer valve seat body and the inner sound-absorbing layer are connected during injection molding. The molten material forming the sound-absorbing layer bonds with the inner wall of the cavity to form a stable interlayer interface, eliminating the need for additional bonding or assembly processes. This fundamentally eliminates the risk of noise reduction layer detachment and failure in post-assembly designs, while also simplifying the production process and reducing manufacturing costs.

[0019] The valve seat body provides the mechanical strength, rigidity, and sealing precision required by the check valve, ensuring that the normal operation of the check valve is not affected; the sound-absorbing layer focuses on acoustic absorption. The valve seat body and the sound-absorbing layer are set inside and outside, each performing its own function and complementing each other, achieving synergistic optimization of structural function and noise reduction function.

[0020] The method for forming a check valve provided by the present invention sequentially forms the valve seat body and the sound-absorbing layer through injection molding. During the forming of the sound-absorbing layer, the sound-absorbing layer and the valve seat body are fused together at the interface, which improves the connection strength. No additional bonding or assembly process is required, which fundamentally eliminates the hidden danger of noise reduction layer falling off and failing in the post-assembly scheme. At the same time, it simplifies the production process and reduces manufacturing costs.

[0021] The fume extraction device provided by this invention uses the aforementioned check valve, which can reduce noise at the check valve without requiring additional bonding or assembly processes, eliminating the risk of the noise reduction layer falling off, and at the same time simplifying the production process and reducing manufacturing costs. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the fume extraction device provided by the present invention; Figure 2 This is a schematic diagram of the check valve provided by the present invention; Figure 3 This is a cross-sectional view of the check valve provided by the present invention.

[0023] In the picture: 100. Body; 110. Main unit box; 120. Smoke hood; 200. Check valve; 210. Valve seat body; 211. Inner shell; 212. Outer shell; 220. Mounting flange; 230. Pipe fitting; 240. Sound-absorbing layer. Detailed Implementation

[0024] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar components or components having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0025] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; a mechanical connection or an electrical connection; a direct connection or an indirect connection through an intermediate medium; or the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0026] In the description of this invention, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0027] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0028] like Figure 1As shown, the present invention provides a fume extraction device that can extract and exhaust cooking fumes generated during cooking to improve the cooking environment. The fume extraction device includes a body 100, a fan installed inside the body 100, and a check valve 200. After the fan is started, it can drive airflow, thereby allowing external cooking fumes to enter the body 100 for filtration, and then pass through the fan and check valve 200 in sequence before being discharged outdoors.

[0029] In some embodiments, the main body 100 includes a main unit housing 110 and a fume hood 120 communicating with the main unit housing 110. The fume hood 120 is provided with a fume inlet and a filter screen is provided at the fume inlet to filter oil fumes. The fan is located inside the main unit housing 110. The range hood can be a top-mounted or side-mounted type, and there is no limitation here.

[0030] In other embodiments, the fume extraction device may also be an integrated stove or a downdraft fume extraction device.

[0031] In some embodiments, such as Figure 2 As shown, the check valve 200 includes a valve seat body 210, a mounting flange 220, and a pipe connector 230. The valve seat body 210 includes an air inlet end and an air outlet end. The air inlet end is connected to the mounting flange 220, which is used to connect to the fan. The air outlet end is connected to the pipe connector 230 to facilitate connection to external pipelines.

[0032] refer to Figure 2 It is known that the cross-sectional shape of the air inlet end of the valve seat body 210 is polygonal, and the cross-sectional shape of the air outlet end of the valve seat body 210 is circular. After the airflow is accelerated by the fan, it is discharged from the inside of the fume extraction equipment. When flowing through the check valve 200, due to the change in the channel cross-section and the adjustment of the airflow direction, the local airflow velocity increases sharply. The high-speed airflow impacts the inner wall surface of the valve seat body 210 and induces vortex shedding, generating broadband airflow noise. The airflow velocity at this location is at the highest level in the entire smoke exhaust channel, so its noise contribution is particularly prominent.

[0033] To solve the above problems, combined with Figure 2 and Figure 3 As shown, the valve seat body 210 is formed by injection molding, and a cavity is simultaneously formed in the circumferential sidewall of the valve seat body 210; the check valve 200 also includes a sound-absorbing layer 240, which is located in the cavity. The sound-absorbing layer 240 is injection molded and welded to the inner wall of the cavity during molding.

[0034] By setting a sound-absorbing layer 240 in the side wall cavity of the valve seat body 210, in-situ noise reduction of the check valve 200 can be achieved. That is, noise reduction is performed at the source of noise generation, so that the sound wave energy carried by the airflow can be effectively absorbed by the sound-absorbing layer 240 when passing through the inner channel of the check valve 200, thereby reducing the radiated noise of the air outlet from the source. The valve seat body 210 located on the outer layer and the sound-absorbing layer 240 located on the inner layer are connected during the injection molding process. The liquid molten material of the sound-absorbing layer 240 can form a stable interlayer bonding interface with the inner wall of the cavity, without the need for additional bonding or assembly processes. This fundamentally eliminates the hidden danger of noise reduction layer falling off and failing in the post-assembly scheme, while simplifying the production process and reducing manufacturing costs.

[0035] The valve seat body 210 provides the mechanical strength, rigidity, and sealing precision required for the check valve 200, ensuring that the normal operation of the check valve 200 is not affected; the sound-absorbing layer 240 focuses on acoustic absorption. The valve seat body 210 and the sound-absorbing layer 240 are set inside and outside, each performing its own function and complementing each other's advantages, achieving synergistic optimization of structural function and noise reduction function.

[0036] In some other embodiments, the valve seat body 210 may have a cavity formed only in part of the circumferential sidewall, which can also achieve the purpose of noise reduction.

[0037] To ensure the strength of the check valve 200, in some embodiments, the strength of the valve seat body 210 is greater than the strength of the sound-absorbing layer 240, so as to meet the strength of the valve seat body 210 and thus provide the mechanical strength, rigidity and sealing fit accuracy required for the check valve 200 to operate normally.

[0038] In some embodiments, the valve seat body 210 is injection molded from a first material, and the sound-absorbing layer 240 is injection molded from a second material, wherein the density of the first material is higher than that of the second material. The high density of the first material makes the structure of the valve seat body 210 compact, and the high density can improve sufficient strength.

[0039] In some embodiments, the melting point of the valve seat body 210 is higher than that of the sound-absorbing layer 240, so that when the molten material of the sound-absorbing layer 240 is in contact with the valve seat body 210, the valve seat body 210 can remain stable, avoiding damage to the structure of the valve seat body 210 when the sound-absorbing layer 240 is being formed, and ensuring that the sound-absorbing layer 240 and the valve seat body 210 can be connected by the injection molding process.

[0040] In some embodiments, the valve seat body 210 is injection molded from acrylonitrile-butadiene-styrene copolymer (ABS), polypropylene (PP), or PC / ABS alloy to meet the requirements for strength and corrosion resistance of the valve seat body 210.

[0041] In some embodiments, the sound-absorbing layer 240 is a foamed layer. That is, the second material of the formed sound-absorbing layer 240 is a foamed material, and the formed sound-absorbing layer 240 has a porous structure with a large porosity. When the fume extraction equipment is working, noise is generated when the airflow passes through the check valve 200. When the sound waves are incident on the surface of the sound-absorbing layer 240, some of the sound waves are reflected on the surface of the sound-absorbing layer 240, and the remaining sound waves enter the interior of the sound-absorbing layer 240 and undergo multiple reflections and refractions between the foam pore walls. The sound wave energy is gradually dissipated during propagation due to the viscosity loss and heat conduction loss of the foam pore inner wall, thereby achieving a noise reduction effect with good noise reduction performance.

[0042] In other embodiments, the sound-absorbing layer 240 may also be made of other materials that can be molded by injection molding, as long as they can achieve the purpose of sound absorption and noise reduction.

[0043] In some embodiments, the sound-absorbing layer 240 can be injection molded from microcellular polypropylene (MPP), polyester foam (PET), or ethylene-propylene-diene monomer (EPDM) to ensure sound absorption and noise reduction effects.

[0044] In some other embodiments, the sound-absorbing layer 240 may also be made of other materials, and no specific limitations are made here.

[0045] To ensure the sound absorption and noise reduction effect of the sound-absorbing layer 240, in some embodiments, the porosity of the sound-absorbing layer 240 is 20%-60%. For example, typical non-limiting values ​​of the porosity of the sound-absorbing layer 240 can be 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, or 60%.

[0046] In some other embodiments, the porosity of the sound-absorbing layer 240 can be specifically set according to specific sound absorption performance requirements, the size of the check valve 200, and other parameters.

[0047] It should be noted that the noise generated by the airflow at the check valve 200 is generally broadband airflow noise, that is, composite noise that spans multiple frequency bands including low frequency, mid frequency and high frequency, with a wide energy coverage; while the pores in the porous foam material affect the frequency band of noise absorbed by the sound-absorbing layer 240.

[0048] To improve the noise reduction effect of the sound-absorbing layer 240, in some embodiments, the sound-absorbing layer 240 includes pores with a diameter of 0.1mm-2mm to meet the sound absorption effect of broadband airflow noise.

[0049] For example, the diameter of the bubble is 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm or 2mm.

[0050] In some other embodiments, the diameter of the pores in the sound-absorbing layer 240 can be specifically set according to specific sound absorption performance requirements, the size of the check valve 200, and other parameters.

[0051] In some embodiments, the thickness of the sound-absorbing layer 240 is 50%-70% of the total wall thickness of the check valve 200, so as to ensure that both the sound-absorbing layer 240 and the sidewall of the cavity have a certain thickness. While ensuring the noise absorption effect, it can also ensure the overall strength of the check valve 200, thereby meeting the usage requirements.

[0052] For example, the thickness of the sound-absorbing layer 240 is 50%, 55%, 60%, 65%, or 70% of the total wall thickness of the backflow valve 200.

[0053] like Figure 3 As shown, the valve seat body 210 includes an inner shell 211 and an outer shell 212, with a cavity formed between the inner shell 211 and the outer shell 212. The total wall thickness of the check valve 200 refers to the sum of the thickness of the inner shell 211, the thickness of the outer shell 212, and the thickness of the sound-absorbing layer 240.

[0054] In some embodiments, the inner shell 211 is provided with a window, through which part of the sound-absorbing layer 240 can be exposed. On the one hand, this increases the direct contact between airflow-generated noise and the sound-absorbing layer 240, making the window a sound-absorbing port on the inner shell 211, which is beneficial for sound waves to directly enter the sound-absorbing layer 240 for refraction and dissipation, thereby improving the sound absorption and noise reduction effect. On the other hand, the window can serve as an injection port for the second material during the injection molding of the sound-absorbing layer 240, and can be blocked by the mold side core during injection molding to ensure the sealing of the molding cavity.

[0055] In some embodiments, multiple windows can be provided, spaced apart circumferentially along the valve seat body 210, to ensure that the foaming material fully fills the molding cavity and avoids filling dead corners.

[0056] In some other embodiments, the window may also be disposed on the housing 212, which is not limited here.

[0057] In some embodiments, the mounting flange 220 and / or pipe fitting 230 are integrally formed with the valve seat body 210 to improve connection strength, simplify the process, and reduce costs.

[0058] The present invention also provides a method for molding a check valve, which can be used to mold the check valve 200 described above. When molding the check valve 200, the valve seat body 210 is first injection molded using a first material, so that a cavity is formed in the circumferential sidewall of the valve seat body 210.

[0059] Specifically, the forming mold has a first cavity for forming the valve seat body 210 and a second cavity for forming the sound-absorbing layer 240. The first cavity and the second cavity are formed sequentially by a movable core or slider. When forming the valve seat body 210, the mold is closed, the movable core or slider fills the second cavity, molten first material is injected into the first cavity, and the valve seat body 210 is formed after pressure holding and cooling.

[0060] Subsequently, the core or slider is moved to expose the second cavity, wherein the inner wall of the cavity of the valve seat body 210 forms at least a portion of the second cavity. Molten second material is injected into the second cavity, and after pressure holding and cooling molding, a sound-absorbing layer 240 is formed. During the injection of the second material, the molten second material fuses with the inner wall of the cavity to form a weld layer connecting the sound-absorbing layer 240 and the valve seat body 210.

[0061] In other embodiments, the valve seat body 210 may also be formed in other ways, such as soluble core injection molding, blow molding, or compression molding with mating side core pulling, as long as it can form a valve seat body 210 with a cavity in the side wall, and there is no limitation here.

[0062] In some embodiments, the cell size and porosity of the sound-absorbing layer 240 can be effectively controlled by adjusting process parameters such as the type and amount of the second material, the injection pressure and the holding time, so that the cell diameter is 0.1mm-2mm and the porosity of the sound-absorbing layer 240 is 20%-60%.

[0063] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A check valve, characterized in that, include: A valve seat body (210) is injection molded, and at least a portion of the circumferential sidewall of the valve seat body (210) has a cavity formed therein. A sound-absorbing layer (240) is located inside the cavity. The sound-absorbing layer (240) is injection molded and welded to the inner wall of the cavity.

2. The check valve according to claim 1, characterized in that, The strength of the valve seat body (210) is greater than the strength of the sound-absorbing layer (240); And / or, the melting point of the valve seat body (210) is higher than the melting point of the sound-absorbing layer (240); And / or, the density of the valve seat body (210) is greater than the density of the sound-absorbing layer (240).

3. The check valve according to claim 1, characterized in that, The sound-absorbing layer (240) is a foamed layer.

4. The check valve according to claim 3, characterized in that, The porosity of the sound-absorbing layer (240) is 20%-60%; And / or, the sound-absorbing layer (240) includes pores with a diameter of 0.1 mm to 2 mm.

5. The check valve according to any one of claims 1-4, characterized in that, The thickness of the sound-absorbing layer (240) is 50%-70% of the total wall thickness of the check valve.

6. The check valve according to any one of claims 1-4, characterized in that, The total wall thickness of the check valve is 4mm-6mm.

7. The check valve according to any one of claims 1-4, characterized in that, The valve seat body (210) is injection molded from acrylonitrile-butadiene-styrene copolymer, polypropylene, or PC / ABS alloy.

8. The check valve according to any one of claims 1-4, characterized in that, The sound-absorbing layer (240) is injection molded from micro-foamed polypropylene, polyester foam or EPDM foam material.

9. A fume extraction device, characterized in that, include: Body (100); A fan is disposed inside the body (100), and the fan includes an air outlet; The check valve as described in any one of claims 1-8, wherein the valve seat body (210) is connected to the air outlet.

10. A method for molding a check valve, characterized in that, A method for molding a check valve as described in any one of claims 1-8, wherein the molding method of the check valve comprises: The valve seat body (210) is injection molded from a first material, and a cavity is formed in at least the circumferential sidewall of the valve seat body (210); The cavity is used to form a molding cavity for the sound-absorbing layer (240). A second material is injected into the molding cavity to form the sound-absorbing layer (240). Part of the second material is fused to the inner wall of the cavity to form a fusion layer connecting the sound-absorbing layer (240) and the valve seat body (210).

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