An extractor hood, a noise reduction device and a noise reduction control method

Abstract

The present disclosure relates to a range hood, a noise reduction device and a noise reduction control method. The noise reduction device comprises a cover plate, at least one first sound attenuation channel, a movable module and at least one second sound attenuation channel. The cover plate is arranged at one end of a fluid channel. A plurality of through holes are formed in the cover plate. Each of the through holes corresponds to the first sound attenuation channel and the second sound attenuation channel. The first sound attenuation channel is made of a perforated plate. One end of the first sound attenuation channel is fixedly connected to the corresponding through hole. The movable module comprises a driving member and a movable plate which are connected in transmission. The driving member is arranged on the cover plate. The movable plate is arranged inside the first sound attenuation channel. The movable module is used to adjust the channel cross-sectional area of the first sound attenuation channel. The second sound attenuation channel is made of a perforated plate. One end of the second sound attenuation channel is fixedly connected to the corresponding through hole. The channel cross-sectional area of the second sound attenuation channel is smaller than the initial channel cross-sectional area of the first sound attenuation channel. The present disclosure can reduce the noise of medium and low frequencies by controlling the channel cross-sectional area, and optimize the air volume and noise.

Description

Technical Field

[0001] This disclosure relates to the field of range hood technology, and in particular to a range hood, a noise reduction device, and a noise reduction control method. Background Technology

[0002] Range hoods, a common kitchen appliance, are essential for removing cooking fumes during daily cooking. They utilize a motor to drive an impeller that rotates within a centrifugal volute, creating negative pressure to draw away cooking fumes and expel them outdoors. Some technologies increase motor speed to enhance air pressure and thus improve fume extraction performance. However, increasing motor speed also leads to increased noise levels, negatively impacting the user experience. Summary of the Invention

[0003] To address at least one of the aforementioned technical problems, this disclosure provides a range hood, a noise reduction device, and a noise reduction control method.

[0004] According to some embodiments of this disclosure, a noise reduction device is provided for use in a range hood. The range hood includes an upper housing and a fluid channel connected by a flue. A fan system is installed inside the upper housing, and the noise reduction device is installed inside the fluid channel. The noise reduction device includes a cover plate, at least one first silencing channel, a movable module, and at least one second silencing channel. The cover plate is located at one end of the fluid channel near the upper housing and has multiple through holes, which correspond to the first silencing channel and the second silencing channel, respectively. The first silencing channel is made of a perforated plate, and its end near the upper housing is fixedly connected to the corresponding through hole. The movable module includes a drive component and a movable plate connected by a drive mechanism. The drive component is located on the cover plate, and the movable plate is located inside the first silencing channel. The movable module is used to adjust the cross-sectional area of ​​the first silencing channel. The second silencing channel is also made of a perforated plate, and its end near the upper housing is fixedly connected to the corresponding through hole. The cross-sectional area of ​​the second silencing channel is smaller than the initial cross-sectional area of ​​the first silencing channel.

[0005] Based on the above scheme, the silencing channel made of perforated plate cooperates with the fluid channel to form the expansion chamber of the resistive silencer, which can effectively deal with the low and medium frequency noise generated by the range hood. Moreover, the cross-sectional area of ​​the first silencing channel is adjustable, and the cross-sectional area of ​​the channel can be adjusted according to the pressure in the fluid channel, thereby adjusting the flow rate and maintaining the balance between noise and air volume.

[0006] In some possible implementations, the first silencing channel is a rectangular pipe, and the movable module includes two oppositely arranged movable plates. Each movable plate includes a variable wall panel, and ear plates are respectively provided at both ends of the variable wall panel along its length direction. The variable wall panel and the ear plates form a C-shaped frame. The variable wall panel corresponds to one side of the inner wall of the rectangular pipe, and the variable wall panel has the same size as the corresponding inner wall. The ear plate at the end of the variable wall panel near the upper housing is slidably mounted on the cover plate.

[0007] Based on the above scheme, the first silencing channel is set as a rectangular pipe and the movable plate is set as a C-shaped frame. The cross-sectional area of ​​the channel can be changed by moving the movable plate in a straight line, while the cross-section of the channel is always rectangular. This structure is simple and easy to manufacture, and no additional eddies are generated in the channel. It reduces noise while avoiding the generation of new noise.

[0008] In some possible implementations, the variable wall panel is made of a perforated plate.

[0009] Based on the above scheme, the cavity space between the variable wall panel and the corresponding inner wall forms the first expansion chamber, while the cavity space between the outer wall of the first silencing channel and the inner wall of the fluid channel forms the second expansion chamber. The connection of the two expansion chambers can realize the series design of the reactive silencer, which can further reduce and eliminate mid- and low-frequency noise.

[0010] In some possible implementations, the active module includes two driving components, each corresponding to one of the active plates. Each driving component includes a motor and a threaded rod that is driven by the motor. The length direction of the threaded rod is consistent with the movement direction of the corresponding active plate. A driven block is screwed onto the threaded rod. The driven block is fixedly connected to the lug of the corresponding active plate. The rotation of the threaded rod drives the driven block to move along the length direction of the threaded rod.

[0011] Based on the above scheme, by using a motor and a threaded rod in combination, sufficient driving force can be provided to move the movable plate quickly and accurately. Moreover, the drive structure is simple, efficient, and easy to control.

[0012] In some possible implementations, a sound-absorbing layer is provided on the inner wall of the fluid channel, the sound-absorbing layer being made of a sound-absorbing material.

[0013] Based on the above scheme, the sound-absorbing layer set on the inner wall of the fluid channel can act as a resistive silencer. The resistive silencer can effectively absorb and remove high-frequency noise. The sound-absorbing layer and the silencer channel can combine the resistive silencer and the reactive silencer to achieve a wideband noise reduction effect.

[0014] In some possible implementations, the fluid channel is provided with at least one partition plate, which divides the interior of the fluid channel into at least two sub-channels, which correspond to the first silencing channel and the second silencing channel, respectively.

[0015] Based on the above scheme, the partition plate divides the fluid channel into multiple sub-channels, further restricting the flow space of the airflow and avoiding the generation of eddies in the fluid channel, which would lead to increased noise and decreased performance. A silencing channel is set in each sub-channel. By allocating the number of first and second silencing channels, the noise reduction requirements of range hoods with different flow parameters can be adapted, thereby achieving a balance between noise reduction effect and smoke extraction performance.

[0016] In some possible implementations, the partition is made of sound-absorbing material.

[0017] Based on the above scheme, the partition plate made of sound-absorbing material can act as a resistive silencer to absorb high-frequency noise. Then, each sub-channel formed by dividing the fluid channel is a combination of resistive and reactive silencers. That is, each sub-channel is a reactive composite silencer, and the fluid channel contains multiple reactive composite silencers, which can comprehensively deal with broadband noise and improve the noise reduction effect.

[0018] According to other embodiments of this disclosure, a range hood is provided, including an upper housing and a fluid channel connected by a flue, and also including a noise reduction device as described in any of the above embodiments, the noise reduction device being disposed inside the fluid channel.

[0019] According to some other embodiments of this disclosure, a noise reduction control method is provided, applied to a noise reduction device according to any one of the above embodiments. The method includes: acquiring pressure data of a fluid channel in which the noise reduction device is located; determining the channel cross-sectional area of ​​a first silencing channel of the noise reduction device based on the pressure data; and adjusting the movable module of the first silencing channel based on the determined channel cross-sectional area of ​​the first silencing channel.

[0020] Based on the above scheme, the cross-sectional area of ​​the first silencing channel is adjusted in real time by acquiring the pressure data of the fluid channel. While maintaining the performance of the range hood in absorbing oil fumes, the noise reduction capability is improved, thereby maintaining the balance between noise and air volume.

[0021] In some possible implementations, determining the cross-sectional area of ​​the first silencing channel of the noise reduction device based on the pressure data includes: obtaining the fan speed of the range hood where the noise reduction device is located; when the fan speed is less than or equal to a preset speed, the cross-sectional area of ​​the first silencing channel is determined as a first preset channel cross-sectional area; when the fan speed is greater than the preset speed, the cross-sectional area of ​​the first silencing channel is determined as a second preset channel cross-sectional area; wherein the second preset channel cross-sectional area is greater than the first preset channel cross-sectional area.

[0022] Based on the above scheme, the pressure data of the fluid channel can be indirectly determined by obtaining the fan speed of the range hood, which reduces the difficulty of data acquisition and improves the sensitivity and accuracy of control.

[0023] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure.

[0024] Other features and aspects of this disclosure will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0025] To more clearly illustrate the technical solutions and advantages in the embodiments or prior art of this specification, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this specification. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 A schematic diagram of a range hood according to an embodiment of the present disclosure is shown;

[0027] Figure 2 A schematic diagram of a noise reduction device according to an embodiment of the present disclosure is shown;

[0028] Figure 3 A schematic diagram of another noise reduction device according to an embodiment of the present disclosure is shown;

[0029] Figure 4 A cross-sectional schematic diagram of a first silencing channel according to an embodiment of the present disclosure is shown;

[0030] Figure 5 A schematic diagram of the active module of a noise reduction device according to an embodiment of the present disclosure is shown;

[0031] Figure 6 A schematic diagram of another noise reduction device according to an embodiment of the present disclosure is shown;

[0032] Figure 7 A schematic diagram of a partition plate for a fluid channel according to an embodiment of the present disclosure is shown;

[0033] Figure 8 A flowchart of a noise reduction control method according to an embodiment of the present disclosure is shown.

[0034] In the picture:

[0035] 1-Cover plate; 2-First silencing channel; 3-Movable plate; 31-Variable wall panel; 32-Ear plate; 4-Driver; 41-Motor; 42-Threaded rod; 43-Driven block; 5-Second silencing channel; 6-Separator plate; 7-Fluid channel. Detailed Implementation

[0036] The technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this specification, and not all embodiments. Based on the embodiments in this specification, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0037] 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 non-exclusive inclusion; for example, a process, method, system, product, or server 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 devices.

[0038] Various exemplary embodiments, features, and aspects of this disclosure will now be described in detail with reference to the accompanying drawings. The same reference numerals in the drawings denote elements that have the same or similar functions. Although various aspects of the embodiments are shown in the drawings, they are not necessarily drawn to scale unless specifically indicated otherwise.

[0039] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments.

[0040] In this document, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. Furthermore, the term "at least one" in this document means any combination of at least two of any one or more elements. For example, including at least one of A, B, and C can mean including any one or more elements selected from the set consisting of A, B, and C.

[0041] Furthermore, to better illustrate this disclosure, numerous specific details are set forth in the following detailed description. Those skilled in the art will understand that this disclosure can be practiced without certain specific details. In some instances, methods, means, components, and circuits well known to those skilled in the art have not been described in detail in order to highlight the main points of this disclosure.

[0042] Range hoods, a common kitchen appliance, are essential for removing cooking fumes during daily cooking. They utilize a motor to drive an impeller that rotates within a centrifugal volute, creating negative pressure to draw away and expel cooking fumes outdoors. To improve fume extraction, some technologies increase the motor's speed to boost airflow and air pressure. However, as the motor speed increases, the noise level also rises. Furthermore, range hoods generate broadband noise, including low-frequency, mid-frequency, and high-frequency noise. Among these, mid-to-low frequency noise has a greater impact on hearing than high-frequency noise, thus affecting the user experience more significantly.

[0043] To address the aforementioned problems, this disclosure provides a noise reduction device applied to a range hood. Please refer to [link / reference]. Figure 1 The range hood includes an upper casing and a fluid channel 7 connected by a flue. A fan system is installed inside the upper casing, comprising a volute and a centrifugal fan inside the volute. When the centrifugal fan operates, it generates negative pressure within the volute, thereby drawing gas from the fluid channel 7 into the volute. In this embodiment, a noise reduction device is installed inside the fluid channel 7. This device functions to: 1) regulate the gas flow rate within the fluid channel 7 to match the operating conditions of the range hood's fan, preventing pressure imbalance and excess airflow accumulation, thus avoiding performance degradation of the range hood; and 2) directly address the noise generated by airflow impact, reducing broadband noise within the range hood.

[0044] In this disclosure, the term "range hood" should be interpreted broadly, encompassing not only household kitchen appliances such as range hoods, but also any device that includes structural components and objectively performs the function of a range hood, such as integrated cooktops and industrial exhaust systems.

[0045] The noise reduction device of this embodiment includes a cover plate 1 and a first silencing channel 2. Please refer to... Figure 2 The cover plate 1 is located at one end of the fluid channel 7 near the upper housing. The cover plate 1 has a through hole that connects to the end of the first silencing channel 2 near the upper housing. The first silencing channel 2 is made of a perforated plate. Based on this configuration, when the fan system of the upper housing is operating, the airflow carrying oil fume particles mainly flows through the first silencing channel 2. The first silencing channel 2 is a pipe channel made of a perforated plate, which is a filter-type silencer capable of absorbing and canceling noise generated during airflow. The cavity space formed by the inner wall of the fluid channel 7, the outer wall of the first silencing channel 2, and the cover plate 1 is an expansion chamber, which is also a filter-type silencer, further reducing noise from the airflow.

[0046] This disclosure does not limit the size parameters of the perforated plate, i.e., it does not limit the thickness, perforation rate, perforation diameter, or perforation distribution of the perforated plate. The thickness, perforation rate, and perforation diameter of the perforated plate affect the frequency characteristics of the perforated plate silencer. These frequency characteristics should match the noise frequency of the range hood to achieve good sound absorption. Therefore, a perforated plate with appropriate parameters should be selected to fabricate the first silencing channel 2 according to the actual noise frequency band of the range hood. In some possible embodiments, the size parameters of the perforated plate include: a thickness of ≤1mm, a perforation rate of 1%-3%, a perforation diameter of ≤1mm, and uniform perforation distribution.

[0047] The embodiments disclosed herein do not limit the shape of the first silencing channel 2. That is, the first silencing channel 2 can be a circular pipe channel, a rectangular pipe channel, or a pipe with other cross-sectional shapes, such as a triangular cross-section, a hexagonal cross-section, an octagonal cross-section, or other regular polygonal cross-sections, as well as other irregular cross-sections.

[0048] When the range hood speed is changed, the motor 41 speed increases, leading to increased airflow. Consequently, the flow rate within the first silencer channel 2 also increases. However, the channel volume of the first silencer channel 2 is fixed, meaning there is an upper limit to the increase in flow rate. Furthermore, the increased flow rate leads to increased fluid pressure, which in turn affects the range hood's smoke extraction efficiency. In addition, the increased motor speed also increases noise. Clearly, the noise reduction device based on the above embodiment can only achieve noise reduction under fixed operating conditions of the range hood. When the range hood speed is changed or the motor 41 speed within the range hood changes, the noise reduction device cannot effectively balance noise reduction and airflow.

[0049] To address the aforementioned issue of balancing noise reduction and airflow, please refer to some embodiments of this disclosure. Figure 3The noise reduction device includes a cover plate 1, a first silencing channel 2, and a movable module. The cover plate 1 is located at one end of the fluid channel 7 near the upper housing, and has a through hole that connects to the end of the first silencing channel 2 near the upper housing. The movable module includes a drive component 4 and a movable plate 3 connected by a transmission connection. The drive component 4 is located on the cover plate 1, and the movable plate 3 is located inside the first silencing channel 2. The movable module is used to adjust the flow space of the first silencing channel 2. Based on the above configuration, when the range hood switches gears or the motor 41 inside the range hood changes speed, the flow space of the first silencing channel 2 can be adjusted through the movable module to keep the flow in the first channel consistent with the operating conditions of the range hood, thereby optimizing the noise reduction performance and the smoke extraction performance, and maintaining a balance between noise reduction and airflow.

[0050] The embodiments disclosed herein do not limit the specific scheme of the active module. That is to say, neither the configuration selection of the driving component 4 nor the specific structure of the active plate 3 is limited. The driving component 4 can be selected as electric drive, pneumatic drive, hydraulic drive, etc. It should be understood that the specific structure of the active module is related to the structure of the first silencing channel 2. For example, in one specific embodiment, when the first silencing channel 2 is composed of multiple circular pipes arranged in parallel, the active plate 3 can be set as a cover plate 1 for the circular pipes. The circular pipes covered by the active plate 3 cannot conduct electricity. The driving component 4 moves the active plate 3 to adjust the number of covered circular pipes, thereby adjusting the flow rate of the first silencing channel 2. In another specific embodiment, when the first silencing channel 2 is a single pipe channel, the active plate 3 is set on the inner wall of the pipe channel. There is an angle between the active plate 3 and the inner wall of the pipe channel, and the active plate 3 can rotate relative to the inner wall of the pipe channel. The driving plate adjusts the angle between the active plate 3 and the inner wall of the pipe channel by controlling the rotation of the active plate 3. The closer the angle is to 90°, the greater the resistance of the active plate 3 to the fluid movement in the channel, and the smaller the corresponding channel flow rate, thereby achieving flow rate regulation.

[0051] In some possible implementations, the first anechoic channel 2 is integrated with the movable plate 3. For example, please refer to... Figure 4 The first silencing channel 2 is an irregularly shaped pipe, which is formed by splicing together multiple long straight plates. Its pipe cross-section is a multi-pointed star shape. By setting the driving component 4, the pipe wall of the irregularly shaped pipe can be controlled to contract towards the pipe axis or expand away from the pipe axis, thereby adjusting the size of the channel cross-sectional area and realizing the flow rate regulation.

[0052] In some embodiments of this disclosure, the first silencing channel 2 is a rectangular pipe, and the movable module can adjust the cross-sectional area of ​​the first silencing channel 2. Please refer to... Figure 5The active module includes two opposing active plates 3. Each active plate 3 includes a variable wall plate 31, and ear plates 32 are respectively provided at both ends of the variable wall plate 31 along its length direction. The variable wall plate 31 and ear plates 32 form a C-shaped frame. The variable wall plate 31 corresponds to one inner wall of the rectangular pipe, and the size of the variable wall plate 31 is consistent with the corresponding inner wall. The ear plate 32 at the end of the variable wall plate 31 near the upper box is slidably installed on the cover plate 1. Based on the above configuration, the significance of choosing a rectangular pipe for the first silencing channel 2 is that the airflow velocity distribution in the rectangular pipe is uniform, reducing the probability of generating airflow vortices and reducing the intensity of airflow impact on the inner wall of the first silencing channel 2, so as to avoid generating new airflow impact noise. By setting the active plate 3 as a C-shaped frame, the active plate 3 can move in a straight line to realize the change of the channel cross-sectional area. During the change of the channel cross-sectional area, the channel cross-section is always rectangular, and the corresponding flow space is always a cuboid space. Clearly, this structure is simple, efficient, and easy to manufacture. It also avoids generating additional noise and eddies within the channel, maintaining both noise reduction and fume extraction performance. It should be understood that in the above solution, a single movable plate 3 (C-shaped frame) within the first silencing channel 2 is sufficient to change the channel's cross-sectional area. The purpose of using two movable plates 3 is merely to increase the speed of this change and improve the timeliness of noise reduction control. In some low-flow range hoods, a single movable plate 3 may also be chosen.

[0053] In one specific embodiment, the variable wall panel 31 is made of a perforated plate. In the aforementioned embodiments, the variable wall panel 31 is a non-perforated plate, meaning that when the fluid passes through the first silencing channel 2, only the two sides of the non-movable plate 3 provide silencing and noise reduction, while the space between the variable wall panel 31 and the corresponding inner wall is unused. Therefore, based on the configuration of this embodiment, the cavity space between the variable wall panel 31 and the corresponding inner wall forms a first expansion chamber, while the cavity space between the outer wall of the first silencing channel 2 and the inner wall of the fluid channel 7 forms a second expansion chamber. The connection of the two expansion chambers enables a series design of reactive silencers, which can further reduce and eliminate mid-to-low frequency noise. This scheme can improve the space utilization of the first silencing channel 2.

[0054] Based on the above embodiments, please refer to Figure 5The active module includes two driving components 4, which correspond one-to-one with the active plate 3. Each driving component 4 includes a motor 41 and a threaded rod 42 that is connected to the motor 41 for transmission. The length direction of the threaded rod 42 is consistent with the moving direction of the corresponding active plate 3. A driven block 43 is screwed onto the threaded rod 42. The driven block 43 is fixedly connected to the ear plate 32 of the corresponding active plate 3. The rotation of the threaded rod 42 drives the driven block 43 to move along the length direction of the threaded rod 42. Based on the above configuration, the rotation of motor 41 can drive the rotation of threaded rod 42. Since driven block 43 is screwed onto threaded rod 42 and fixedly connected to ear plate 32 of movable plate 3, and since the main body of movable plate 3 (i.e., variable wall plate 31) is consistent with the inner wall of the first silencing channel 2, and ear plate 32 of movable plate 3 is slidably mounted on cover plate 1, the movement path of movable plate 3 is constrained, that is, the movement path of driven block 43 is also constrained. Therefore, when threaded rod 42 rotates, driven block 43 rotates relative to threaded rod 42 and moves along the length direction of threaded rod 42. In the above drive configuration scheme, the significance of choosing motor 41 to provide driving force is that it facilitates the overall control of the range hood, and the driving force of motor 41 is sufficient and can provide sufficient accuracy to move movable plate 3 quickly and accurately.

[0055] It should be understood that the above embodiments only provide an exemplary drive component 4 solution. The motor 41 of the drive component 4 can also be replaced with other power sources of the same type or different types. Power sources of the same type include servo motor 41, direct drive motor 41, etc., and power sources of different types include air pump, oil pump, etc. Furthermore, the transmission structure of the drive component 4 can be flexibly adjusted according to actual needs. For example, the threaded rod 42 can be replaced with a smooth rod and a lead screw. The driven block 43 has a through hole and a threaded hole. The smooth rod passes through the through hole of the driven block 43, while the lead screw passes through the threaded hole. The motor 41 drives the lead screw to rotate, which can also realize the movement of the driven block 43 along the length direction of the lead screw, thereby realizing the opening and closing of the movable plate 3 and achieving the effect of adjusting the channel cross-sectional area of ​​the first noise reduction channel 2. Alternatively, the transmission structure of the drive component 4 can be a telescopic rod driven by the motor 41. The end of the telescopic rod away from the motor 41 is fixedly connected to the ear plate 32 on the cover plate 1 through a connector. The motor 41 drives the telescopic rod to extend or shorten along its length direction, thereby realizing the opening and closing of the movable plate 3 and achieving the effect of adjusting the channel cross-sectional area of ​​the first noise reduction channel 2.

[0056] In one specific embodiment, the active module may also include only one drive element 4, which includes a motor 41 and two threaded rods 42. The two threaded rods 42 are respectively connected to the ear plates 32 on the two movable plates 3 through their respective driven blocks 43. With the above configuration, a single motor 41 can control the opening and closing of the two movable plates 3, and the opening and closing actions of the two movable plates 3 are synchronized, which can improve the control efficiency of the movable plates 3, thereby increasing the adjustment speed of the channel cross-sectional area of ​​the first silencing channel 2.

[0057] This disclosure does not limit the number of first silencing channels 2. There can be one or more first silencing channels 2. When there are two or more first silencing channels 2, this disclosure also does not limit their arrangement. It is understood that the number, position, and structure of the first silencing channels 2 should be selected based on the actual flow rate and noise reduction requirements of the range hood. For example, when the flow rate of the range hood is small, and the fluid channel 7 is a flat cube with a cross-section that is rectangular with an aspect ratio greater than 2, then only one first silencing channel 2 can be provided in the fluid channel 7, or two first silencing channels 2 can be provided. When two first silencing channels 2 are provided in the fluid channel 7, they are arranged side-by-side, thereby dividing the fluid channel 7 into two sub-channels; similarly... When the range hood has a large flow rate and the fluid channel 7 is a full-shaped cube, the aspect ratio of the rectangular cross-section of the fluid channel 7 ranges from 0.8 to 1.2. In this case, two or four first silencer channels 2 can be installed within the fluid channel 7. When two first silencer channels 2 are installed, they are arranged side-by-side, thus dividing the fluid channel 7 into two sub-channels. When four first silencer channels 2 are installed, they are arranged in a two-row, two-column configuration, thus dividing the fluid channel 7 into four sub-channels. Furthermore, the number of first silencer channels 2 can also be determined based on the number of fans contained in the range hood; that is, the number of first silencer channels 2 should be consistent with the number of fans.

[0058] In this embodiment, since the first silencing channel 2 needs to meet the requirements of channel cross-sectional area variation, the initial channel cross-sectional area of ​​the first silencing channel 2 is set to be relatively large. The initial channel cross-sectional area is the maximum channel cross-sectional area, which needs to meet the operating conditions of the range hood at its highest setting or the fan at its highest speed. However, in some range hoods, although the flow rate is large, the difference in operating conditions between different settings is not significant. That is, after switching settings, the fan speed does not change much, meaning the corresponding flow rate change is also small. Therefore, the variation range of the channel cross-sectional area of ​​the first silencing channel 2 also needs to be relatively small. Based on the above embodiments, it can be seen that the fluid channel 7 of a high-flow range hood is relatively large, and multiple first silencing channels 2 may be required. However, in order to meet the requirements of the flow rate variation range, the variation range of the channel cross-sectional area of ​​the first silencing channel 2 needs to be relatively small. To address the aforementioned issues, possible solutions include: setting up multiple first silencing channels 2, but reducing the volume of each first silencing channel 2; setting up a single first silencing channel 2, increasing its volume; or setting up multiple first silencing channels 2, but not each of these channels has a variable cross-sectional area function, i.e., not every first silencing channel 2 has a movable module. These three solutions also have limitations. Specifically, the cavity space between the inner wall of the fluid channel 7 and the outer wall of the first silencing channel 2 needs to be sufficiently large; otherwise, an effective expansion chamber cannot be formed, leading to a decrease in noise reduction effect.

[0059] To maintain a balance between noise reduction performance and space utilization of the fluid channel 7, please refer to some embodiments of this disclosure. Figure 6The noise reduction device includes a cover plate 1, a first silencing channel 2, a movable module, and a second silencing channel 5. The cover plate 1 is located at one end of the fluid channel 7 near the upper housing, and has multiple through holes corresponding to the first silencing channel 2 and the second silencing channel 5. The first silencing channel 2 is made of a perforated plate, and its end near the upper housing is fixedly connected to the corresponding through hole. The movable module includes a drive component 4 and a movable plate 3 connected by a drive mechanism. The drive component 4 is located on the cover plate 1, and the movable plate 3 is located inside the first silencing channel 2. The movable module is used to adjust the cross-sectional area of ​​the first silencing channel 2. The second silencing channel 5 is also made of a perforated plate, and its end near the upper housing is fixedly connected to the corresponding through hole. The cross-sectional area of ​​the second silencing channel 5 is smaller than the initial cross-sectional area of ​​the first silencing channel 2. Based on the above configuration, the first silencing channel 2, as a channel with a variable cross-sectional area, is used to cope with the demand for flow rate changes. The second silencing channel 5 does not have the function of changing the cross-sectional area, but the volume of the second silencing channel 5 is smaller than that of the first silencing channel 2. That is to say, by setting the second silencing channel 5, the internal space of the fluid channel 7 can be effectively utilized. The first silencing channel 2 and the second silencing channel 5 work together to ensure that the overall channel cross-sectional area change range of the fluid channel 7 corresponds to the flow rate change range of the range hood, and also to ensure that the overall flow rate of the fluid channel 7 corresponds to the flow rate of the range hood. In addition, the first silencing channel 2 and the second silencing channel 5 are independent silencers, which can perform noise reduction separately. The combined use of the first silencing channel 2 and the second silencing channel 5 can further improve the noise reduction effect.

[0060] This disclosure does not limit the number of second silencing channels 5; the number of second silencing channels 5 can be one or more. When the number of second silencing channels 5 is two or more, this disclosure does not limit the arrangement of the second silencing channels 5. It is understood that since the volume of the second silencing channel 5 is smaller than the volume of the first silencing channel 2, and the purpose of setting the second silencing channel 5 is to assist in regulating the overall flow rate of the fluid channel 7 and improve noise reduction performance, multiple second silencing channels 5 are selected to better perform their function.

[0061] In some embodiments of this disclosure, please refer to Figure 6The noise reduction device includes a first silencing channel 2 and four second silencing channels 5. The first silencing channel 2 is located in the left half of the fluid channel 7, and the four second silencing channels 5 are located in the right half of the fluid channel 7, arranged in a two-row, two-column configuration. Based on this configuration, the first silencing channel 2 has a variable cross-sectional area for adjusting the flow rate of the fluid channel 7, while the second silencing channels 5 have a fixed cross-sectional area to ensure the overall flow rate of the fluid channel 7. Both the first silencing channel 2 and the second silencing channel 5 are filter-type silencers capable of reducing noise in the airflow.

[0062] In this embodiment, the first silencing channel 2 is a silencer made of a perforated plate. The inner wall of the fluid channel 7, the outer wall of the first silencing channel 2, and the cavity space of the cover plate 1 form an expansion chamber. The expansion chamber is located outside the first silencing channel 2. The first silencing channel 2 and the expansion chamber together form a reactive silencer. The reactive silencer can effectively reduce the mid-to-low frequency noise in the range hood, and mid-to-low frequency noise has a significant impact on human hearing. In actual operation, the noise generated by the range hood is broadband noise, so the noise of the range hood also includes some high-frequency noise. Therefore, the noise reduction device should have the ability to reduce high-frequency noise in addition to having mid-to-low frequency noise reduction performance.

[0063] To achieve the high-frequency noise reduction function of the noise reduction device, in some embodiments of this disclosure, a sound-absorbing layer is provided on the inner wall of the fluid channel 7. The sound-absorbing layer is made of sound-absorbing material. Based on the above configuration, the sound-absorbing layer provided on the inner wall of the fluid channel 7 can act as a resistive silencer. The resistive silencer can effectively absorb and remove high-frequency noise. The sound-absorbing layer, in conjunction with the silencer channel, can achieve a combination of resistive and reactive silencers, forming an impedance composite silencer. This silencer can reduce noise in low-frequency, mid-frequency, and high-frequency bands, thereby achieving a wideband noise reduction effect.

[0064] In this embodiment, the principle of the sound-absorbing material is that when sound enters the material surface, part of the sound energy is reflected, part penetrates the material, and the remaining part is lost due to the vibration of the component material or friction between the sound and the medium during propagation, resulting in the sound energy being converted into heat energy. In other words, the sound is absorbed by the material. This embodiment does not limit the specific selection and configuration of the sound-absorbing material; that is, the sound-absorbing material can be a porous material, a resonant material, or a material with a special structure. To reduce costs, the sound-absorbing material can be selected as porous materials such as sound-absorbing cotton or foam plastic.

[0065] In some embodiments of this disclosure, please refer to Figure 7The fluid channel 7 is internally equipped with at least one partition plate 6, which divides the interior of the fluid channel 7 into at least two sub-channels, corresponding to the first silencing channel 2 and the second silencing channel 5, respectively. Based on this configuration, the partition plate 6 divides the fluid channel 7 into multiple sub-channels, further restricting the airflow space. When the airflow flows from one end of a sub-channel to the other, the airflow velocity distribution is uniform, and the pressure distribution within the corresponding channel is also uniform, thereby preventing the generation of eddies within the fluid channel 7, which would lead to increased noise and decreased performance. The purpose of setting a silencing channel within each sub-channel is to simultaneously optimize noise reduction and fume extraction performance. The solution in this embodiment improves the compatibility of the noise reduction device. By allocating the number of the first silencing channel 2 and the second silencing channel 5, it can adapt to the noise reduction requirements of range hoods with different flow parameters, thereby achieving a balance between noise reduction and fume extraction performance.

[0066] To further improve the noise reduction effect of the noise reduction device, in some embodiments of this disclosure, the partition plate 6 is made of sound-absorbing material. Based on the above scheme, the partition plate 6 made of sound-absorbing material can act as a resistive silencer to absorb high-frequency noise. Then, each sub-channel formed by dividing the fluid channel 7 is a combination of a resistive silencer and a reactive silencer, that is, each sub-channel is a resistive-reactive composite silencer, and the fluid channel 7 contains multiple resistive-reactive composite silencers, which can comprehensively deal with broadband noise and improve the noise reduction effect.

[0067] The embodiments of this disclosure also provide a range hood, which includes an upper housing and a fluid channel 7 connected by a flue, and also includes a noise reduction device as described in any of the above embodiments, the noise reduction device being disposed inside the fluid channel 7.

[0068] The embodiments of this disclosure also provide a noise reduction control method, which is applied to the noise reduction device described in any of the above embodiments. The method first determines the operating condition of the range hood, that is, analyzes the flow rate of the fan inside the range hood, and then adjusts the flow rate of the fluid channel 7 inside the range hood according to the operating condition, so that the flow rate of the fluid channel 7 corresponds to the flow rate generated by the fan, thereby avoiding excess airflow from accumulating inside the range hood, reducing airflow impact, and lowering noise.

[0069] Please refer to Figure 8 The flowchart of a noise reduction control method provided in this embodiment of the present disclosure is shown. The method includes:

[0070] S101. Obtain the pressure data of the fluid channel 7 where the noise reduction device is located.

[0071] In this embodiment of the disclosure, the pressure data is not limited to the directly measured pressure value. It can also be other parameter values ​​related to the pressure of the fluid channel 7. For example, the pressure of the fluid channel 7 is closely related to the flow rate when the fan is running, and the flow rate when the fan is running is related to the fan speed. The pressure data can be obtained by measuring the fan speed and establishing the relationship between the fan speed and the pressure value. Alternatively, the pressure data can be obtained by obtaining the operating level of the range hood and based on the relationship between the operating level and the pressure value of the fluid channel 7.

[0072] S102. Based on the pressure data, determine the cross-sectional area of ​​the first silencing channel 2 of the noise reduction device.

[0073] In this embodiment of the disclosure, the cross-sectional area of ​​the first silencing channel 2 should satisfy the following: it should be able to reduce the pressure of the fluid channel 7 to the normal range, and the noise energy of the range hood should be lower than a preset threshold after the pressure is reduced.

[0074] S103. Adjust the movable module of the first silencing channel 2 according to the determined channel cross-sectional area of ​​the first silencing channel 2.

[0075] Based on the above scheme, the cross-sectional area of ​​the first silencing channel 2 is adjusted in real time by acquiring the pressure data of the fluid channel 7. While maintaining the performance of the range hood in absorbing oil fumes, the noise reduction capability is improved, thereby maintaining the balance between noise and air volume.

[0076] In one specific embodiment, the pressure data is determined by the fan speed of the range hood, then step S102 includes:

[0077] Obtain the fan speed of the range hood where the noise reduction device is located;

[0078] When the fan speed is less than or equal to the preset speed, the cross-sectional area of ​​the first silencing channel 2 is determined to be the first preset channel cross-sectional area;

[0079] When the fan speed is greater than the preset speed, the cross-sectional area of ​​the first silencing channel 2 is determined to be the cross-sectional area of ​​the second preset channel.

[0080] The cross-sectional area of ​​the second preset channel is larger than that of the first preset channel.

[0081] Based on the above scheme, the pressure data of fluid channel 7 can be indirectly determined by obtaining the fan speed of the range hood, which reduces the difficulty of data acquisition and improves the sensitivity and accuracy of control.

[0082] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A noise reduction device applied in a range hood, the range hood comprising an upper housing and a fluid channel (7) connected by a flue, the upper housing having a fan system inside, and the fluid channel (7) having the noise reduction device inside, characterized in that: The noise reduction device includes a cover plate (1), at least one first silencing channel (2), a movable module, and at least one second silencing channel (5). The cover plate (1) is located at one end of the fluid channel (7) near the upper housing. The cover plate (1) has multiple through holes, which correspond to the first silencing channel (2) and the second silencing channel (5) respectively. The first silencing channel (2) is made of a perforated plate, and the end of the first silencing channel (2) near the upper box is fixedly connected to the corresponding through hole; The active module includes a drive component (4) and an active plate (3) connected by a transmission. The drive component (4) is disposed on the cover plate (1), and the active plate (3) is disposed inside the first silencing channel (2). The active module is used to adjust the channel cross-sectional area of ​​the first silencing channel (2). The second silencing channel (5) is made of a perforated plate. The end of the second silencing channel (5) near the upper housing is fixedly connected to the corresponding through hole. The cross-sectional area of ​​the second silencing channel (5) is smaller than the initial cross-sectional area of ​​the first silencing channel (2).

2. The noise reduction device according to claim 1, characterized in that: The first silencing channel (2) is a rectangular pipe. The movable module includes two movable plates (3) arranged opposite to each other. Each movable plate (3) includes a variable wall plate (31). The variable wall plate (31) has ear plates (32) arranged at both ends along its length direction. The variable wall plate (31) and the ear plates (32) form a C-shaped frame. The variable wall panel (31) corresponds to one side of the inner wall of the rectangular pipe, and the variable wall panel (31) has the same size as the corresponding inner wall. The ear plate (32) of the variable wall panel (31) near the upper box is slidably installed on the cover plate (1).

3. The noise reduction device according to claim 2, characterized in that: The variable wall panel (31) is made of perforated plate.

4. The noise reduction device according to claim 2, characterized in that: The active module includes two driving components (4), each corresponding to one of the active plates (3). Each driving component (4) includes a motor (41) and a threaded rod (42) that is connected to the motor (41) for transmission. The length direction of the threaded rod (42) is consistent with the moving direction of the corresponding active plate (3). A driven block (43) is screwed onto the threaded rod (42). The driven block (43) is fixedly connected to the ear plate (32) of the corresponding active plate (3). The rotation of the threaded rod (42) drives the driven block (43) to move along the length direction of the threaded rod (42).

5. The noise reduction device according to claim 1, characterized in that: The inner wall of the fluid channel (7) is provided with a sound-absorbing layer, which is made of sound-absorbing material.

6. The noise reduction device according to claim 1, characterized in that: The fluid channel (7) is provided with at least one partition plate (6) inside, which divides the interior of the fluid channel (7) into at least two sub-channels, which correspond to the first silencing channel (2) and the second silencing channel (5) respectively.

7. The noise reduction device according to claim 6, characterized in that: The partition plate (6) is made of sound-absorbing material.

8. A range hood, comprising an upper housing and a fluid channel (7) connected via a flue, characterized in that: It also includes a noise reduction device according to any one of claims 1-7, the noise reduction device being disposed inside the fluid channel (7).

9. A noise reduction control method, applied in a noise reduction device according to any one of claims 1-7, characterized in that, The method includes: Obtain the pressure data of the fluid channel (7) where the noise reduction device is located; Based on the pressure data, determine the cross-sectional area of ​​the first silencing channel (2) of the noise reduction device; Adjust the movable module of the first silencing channel (2) according to the determined channel cross-sectional area.

10. The method according to claim 9, characterized in that, The step of determining the cross-sectional area of ​​the first silencing channel (2) of the noise reduction device based on the pressure data includes: Obtain the fan speed of the range hood where the noise reduction device is located; When the fan speed is less than or equal to the preset speed, the cross-sectional area of ​​the first silencing channel (2) is determined to be the first preset channel cross-sectional area; When the fan speed is greater than the preset speed, the cross-sectional area of ​​the first silencing channel (2) is determined to be the second preset channel cross-sectional area; The cross-sectional area of ​​the second preset channel is larger than that of the first preset channel.

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