Vibration testing device for range hood and design method thereof
By constructing a finite element model and performing modal and stiffness verification, a range hood vibration testing device was designed, which solved the problem that existing devices could not simulate the vibration of range hoods, achieved more accurate and stable test results, and extended the device's lifespan.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- VATTI CORP LTD
- Filing Date
- 2025-12-31
- Publication Date
- 2026-05-29
AI Technical Summary
Existing motor vibration testing devices cannot simulate the vibration of a range hood during operation and are easily affected by resonance and forced vibration, leading to inaccurate testing and shortened device lifespan.
A vibration testing device for a range hood is designed. By constructing a finite element model, modal verification and stiffness verification are performed to ensure that the natural frequency is outside the motor excitation frequency range. A virtual load is applied at the motor installation position to simulate vibration, and the maximum displacement is controlled to be less than a threshold to optimize the dynamic characteristics of the structure.
It improves the accuracy of testing and the stability of the device, reduces resonance and noise, ensures the reliability and authenticity of test results, and enhances the service life and versatility of the testing device.
Smart Images
Figure CN122108499A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the technical field of range hood vibration testing equipment, and in particular to a range hood vibration testing device and its design method. Background Technology
[0002] Nowadays, after motors are manufactured in the factory, they need to undergo comprehensive testing, and motor vibration testing is an important step in motor testing. If the vibration generated by the motor during operation exceeds the reasonable range, it will not only accelerate the wear of internal parts and shorten the motor's lifespan, but may also transmit vibration through equipment connections, causing problems such as resonance and abnormal noise. Currently, common motor vibration testing devices on the market cannot simulate the vibration conditions of a range hood during operation, and simple vibration tables are easily affected by resonance and forced vibration. Summary of the Invention
[0003] This application addresses the shortcomings of existing methods by providing a range hood vibration testing device and its design method, thereby solving the technical problem that existing motor vibration testing devices cannot simulate the vibration of a range hood during operation.
[0004] In the first aspect, embodiments of this application provide a design method for a vibration testing device for a range hood, which mainly includes: constructing a finite element model of the target range hood vibration testing device; determining whether all natural frequencies of the finite element model are outside a preset motor excitation frequency range; if any natural frequency is within the preset motor excitation frequency range, modifying the current finite element model according to a preset first modification scheme until all natural frequencies of the current finite element model are outside the preset motor excitation frequency range, so as to pass the modal verification stage; applying a preset virtual load to the finite element model that has passed the modal verification stage to the motor mounting position for vibration simulation, and confirming the maximum displacement of the motor mounting position; if the determined maximum displacement is greater than or equal to a predetermined threshold, modifying the current finite element model according to a preset second modification scheme until the maximum displacement of the motor mounting position of the current finite element model is less than the predetermined threshold, so as to pass the stiffness verification stage, and repeating the modal verification stage; iteratively executing the modal verification stage and the stiffness verification stage until all natural frequencies of the latest finite element model are outside the preset motor excitation frequency range and the maximum displacement of the motor mounting position of the finite element model is less than the predetermined threshold.
[0005] As an optional implementation, the current finite element model is modified according to a preset first modification scheme, including: determining the mode shape corresponding to the natural frequency within a preset motor excitation frequency range; and adding a reinforcing structure and / or increasing the plate thickness in the region of the mode shape where the vibration displacement is the largest.
[0006] As an optional implementation, vibration simulation is performed by applying a preset virtual load at the motor mounting location, including applying three loads with preset directions and preset proportions at the motor mounting location.
[0007] As an optional implementation, the preset direction is configured as three mutually perpendicular directions; the preset ratio is configured as (1.5-2.5):(1.5-2.5):(5.5-6.5).
[0008] As an optional implementation, the preset ratio is configured as 2:2:6.
[0009] As an optional implementation, the current finite element model is modified according to a preset second modification scheme, including: obtaining a displacement cloud map after vibration simulation; and adding a reinforcing structure and / or increasing the plate thickness in the region of the displacement cloud map where the displacement is greater than or equal to the predetermined threshold.
[0010] As an optional implementation, the predetermined threshold is 0.1 mm.
[0011] Secondly, this application provides a design method for a range hood vibration testing device as described in any of the foregoing embodiments. The resulting range hood vibration testing device mainly includes a fan cabinet, a housing, a mounting base, detachably connected side baffles, and detachably connected bottom baffles. An air duct is formed inside the fan cabinet. The housing has a cavity inside, and the fan cabinet is installed within the cavity. An air outlet communicating with the air duct is opened on the top wall of the housing, a first air inlet communicating with the air duct is opened on the side wall of the housing, and a second air inlet communicating with the air duct is opened on the bottom wall of the housing. The mounting base is fixed inside the fan cabinet for installing the motor under test. The detachably connected side baffles are used to close the first air inlet. The detachably connected bottom baffles are used to close the second air inlet. In a first test state, the side baffles are fixed to the side wall of the housing, and the bottom baffles are separated from the bottom wall of the housing. In a second test state, the bottom baffles are fixed to the bottom wall of the housing, and the side baffles are separated from the side wall of the housing.
[0012] As an optional implementation, the mounting base includes multiple support columns and multiple mounting plates; the multiple support columns are distributed circumferentially and their first ends are fixed to the air handling unit; the multiple mounting plates are detachably connected to the second ends of the multiple support columns, and the mounting plates have multiple mounting holes arranged circumferentially; the diameters of the mounting holes of the multiple mounting plates are different to accommodate motors of different specifications.
[0013] As an alternative implementation, the bottom wall of the housing extends in opposite directions to form an extension plate; a plurality of reinforcing plates are spaced apart on the extension plate and connected to the side wall of the housing.
[0014] This application provides a vibration testing device for a range hood and its design method. The technical solution provided by the embodiments of this application brings at least the following beneficial effects: The modal verification stage ensures that all natural frequencies of the finite element model are outside the preset motor excitation frequency range, thus preventing resonance during operation, reducing vibration and noise, and improving test accuracy and device lifespan. The stiffness verification stage applies virtual loads to the motor mounting location for vibration simulation, controlling the maximum displacement to be less than a predetermined threshold, ensuring sufficient stiffness and preventing excessive deformation due to load, thus ensuring the stability and reliability of the testing process. Through iterative execution, modal and stiffness verifications are combined, repeatedly modifying the model until both frequency and displacement requirements are met, improving the robustness and performance of the device. Virtual testing and parameter adjustment optimize the structural dynamic characteristics of the testing device, making the vibration test results more realistically reflect the actual operating state of the range hood, improving the reliability of the test data. The designed range hood vibration testing device can simulate the vibration of the range hood during operation, reducing the impact of resonance and forced vibration.
[0015] With detachable side and bottom baffles, two test states—side air intake and bottom air intake—are clearly defined, creating a multi-functional test platform that eliminates the need for separate design and manufacture of dedicated test fixtures for each test scenario. This significantly improves testing convenience and equipment utilization. The motor under test is mounted on a mounting bracket inside the fan housing, reflecting the motor's actual vibration state under the influence of air ducts and air pressure. This makes the test data closer to the actual working conditions of the range hood, resulting in more accurate and reliable test results. Furthermore, the detachable connection between the motor and the fan housing isolates the motor from interference factors, ensuring the test results purely reflect the motor's inherent vibration characteristics. The test device, based on the aforementioned design method, prevents severe resonance or excessive deformation, thus avoiding interference from the device's own vibration and ensuring the stability of the testing process. It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description
[0016] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1 This is a schematic diagram of the structure of a smoke hood provided in an embodiment of this application; Figure 2 This is a schematic diagram of the structure of a flow guide in a smoke hood provided in an embodiment of this application; Figure 3This is a schematic diagram of another smoke hood provided in an embodiment of this application; Figure 4 This is a schematic diagram of the structure of a smoke hood provided in an embodiment of this application; Figure 5 A schematic diagram of the oblique upward structure of a bottom-inlet type range hood vibration testing device provided in another embodiment of this application; Figure 6 A schematic diagram showing the connection relationship between the air handling unit, housing, mounting base, and motor of a range hood vibration testing device provided in this application embodiment; Figure 7 This is a schematic diagram showing the connection relationship between the air handling unit, outer shell, and mounting base of a range hood vibration testing device provided in an embodiment of this application.
[0017] Figure labels and corresponding explanations: 1: Air compressor; 2: Outer shell; 21: Air outlet; 22: First air inlet; 23: Second air inlet; 24: Extension plate; 25: Reinforcing plate; 3: Mounting base; 31: Support column; 32: Mounting plate; 4: Side baffle; 5: Bottom baffle; 6: Motor. Detailed Implementation
[0018] This application is described in detail below. Examples of embodiments of this application are illustrated 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. Furthermore, detailed descriptions of known technologies that are unnecessary for the features of this application are omitted. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.
[0019] Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the term “comprising” as used in the specification of this application means the presence of the stated feature, integer, step, operation, element, and / or component, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. The term “and / or” as used herein includes all or any unit and all combinations of one or more associated listed items.
[0020] like Figure 1 As shown in the figure, this application provides a design method for a range hood vibration testing device, which mainly includes steps S1-S6: Step S1: Construct the finite element model of the target range hood vibration testing device; Step S2: Determine whether all the natural frequencies of the finite element model are outside the preset excitation frequency range of motor 6; Step S3: If any natural frequency is within the preset excitation frequency range of motor 6, then modify the current finite element model according to the preset first modification scheme until all natural frequencies of the current finite element model are outside the preset excitation frequency range of motor 6, so as to pass the modal verification stage. Step S4: Apply a preset virtual load to the motor 6 mounting position of the finite element model that has passed the modal verification stage to perform vibration simulation, and confirm the maximum displacement of the motor 6 mounting position. Step S5: If the determined maximum displacement is greater than or equal to the predetermined threshold, modify the current finite element model according to the preset second modification scheme until the maximum displacement of the motor 6 installation position of the current finite element model is less than the predetermined threshold, so as to pass the stiffness verification stage, and repeat the modal verification stage. Step S6: Iteratively execute the modal verification stage and stiffness verification stage until all natural frequencies of the latest finite element model are outside the preset excitation frequency range of motor 6 and the maximum displacement of the motor 6 installation position in the finite element model is less than a predetermined threshold.
[0021] In this embodiment, the finite element model of the target range hood vibration testing device in step S1 mainly includes: establishing a structural model of the product; simplifying the structural model, cleaning up the geometry, and meshing. By collecting relevant data such as design drawings, dimensional parameters, and material properties of the target range hood vibration testing device (hereinafter referred to as the testing device), the structural type, material type, and connection method of the testing device are determined, and a finite element model of the testing device is established based on modeling software (such as ANSYS, Abaqus, etc.).
[0022] The natural frequency in step S2 is the frequency at which the testing device tends to vibrate in its own inherent way when it is not disturbed by external forces. The natural frequency is determined by the properties of the testing device itself. For example, the natural frequency mainly depends on the material (stiffness and elasticity), structure (shape, boundary conditions), and mass distribution of the object. The natural frequency can be obtained through finite element model simulation. The natural frequency is an inherent "vibration rhythm," and it is crucial to ensure that this rhythm never "matches" the rhythm input from the outside world, thereby avoiding resonance and ensuring the accuracy of the test and the safety of the device. When subjected to external impact (e.g., vibration of motor 6), the testing device will not vibrate in only one way. It has a series of inherent, potential vibration modes. In this embodiment, the natural frequencies of the six most likely and highest-energy vibration modes are determined, i.e., the first six natural frequencies. Low-order (e.g., the first six) vibration modes are the easiest to excite and require the least energy. Under the complex vibration excitation of motor 6, if the first six frequencies can be perfectly avoided, the risk of resonance is reduced to a very low level. These modes can be accurately "seen" through simulation.
[0023] In some embodiments, the first stage may be the entire test apparatus swaying back and forth like jelly. The second stage may be lateral twisting. The third stage may be the top plate of the test apparatus vibrating up and down like a drumhead. The fourth, fifth, and sixth stages may be more complex localized twisting and vibration at certain side plates or joints.
[0024] The excitation frequency range of motor 6 in step S2 refers to the frequencies of all periodic vibrations generated by motor 6 during operation. These frequencies constitute a "danger zone" that needs to be avoided. Motor 6 also operates under different conditions in different working modes of the range hood, such as speed settings one, two, three, and stir-fry mode. If the natural frequency of the testing device falls within the excitation frequency range of motor 6, severe resonance will occur, resulting in significant noise. Therefore, it is necessary to ensure that all natural frequencies of the testing device itself are well away from the excitation frequency range of motor 6.
[0025] The aforementioned step S3 involves modal verification, a preliminary step in the entire simulation process. Modal verification reveals the inherent, intrinsic dynamic characteristics of the structure. These characteristics are determined by the structure itself and are independent of externally applied loads. The first six natural frequencies of the test device are calculated, and it is verified whether all six natural frequencies avoid the predetermined excitation frequency range of the range hood motor 6. If any natural frequency falls within the preset excitation frequency range of the motor 6, it indicates that resonance will occur, leading to a sharp increase in amplitude. Therefore, the finite element model of the test device needs to be modified until all natural frequencies of the current finite element model are outside the preset excitation frequency range of the motor 6.
[0026] In step S4 above, the displacement of the motor 6 mounting position refers to the displacement of the "motor 6 mounting point" relative to the entire test device, this "fixed foundation." Ideally, the motor 6 mounting point would remain stationary. In this case, any vibration would be generated by the motor 6 itself. However, in reality, the motor 6 mounting point is elastic; it deforms and vibrates along with the motor 6. To ensure the test device provides a stable and reliable motor 6 mounting position, and to guarantee that the measured vibration data primarily originates from the motor 6 itself, it is necessary to determine the maximum displacement of the motor 6 mounting position. Within the elastic range, structural deformation is proportional to the load. Determining the displacement of the motor 6 mounting point under a specific load through the stiffness verification stage essentially ensures that the test device structure has sufficient stiffness (i.e., the ability to resist deformation).
[0027] Step S5 above involves stiffness verification, which is a performance test of the testing device. The test measures the response result under a specific external force, specifically the maximum displacement. If the determined maximum displacement is greater than or equal to a predetermined threshold, it indicates that the motor 6 mounting point is too soft and unqualified. Therefore, the current finite element model needs to be modified until the maximum displacement of the motor 6 mounting position in the current finite element model is less than the predetermined threshold. Since the finite element model has been modified, the inherent dynamic characteristics of the testing device have changed; therefore, modal verification needs to be performed again.
[0028] In step S5 above, the iterative execution of the modal verification stage and stiffness verification stage means that the finite element model that fails the stiffness verification needs to be modified, and the modified finite element model is re-verified modally. The finite element model that passes the modal verification is then verified for stiffness. If it still fails, the modal verification and stiffness verification are repeated until all the natural frequencies of the finite element model that passes both modal verification and stiffness verification are outside the preset excitation frequency range of motor 6 and the maximum displacement of the motor 6 mounting position of the finite element model is less than a predetermined threshold. Through the modal verification stage, it is ensured that all natural frequencies of the finite element model are outside the preset excitation frequency range of motor 6, thereby preventing resonance during operation, reducing vibration and noise, and improving the accuracy of the test and the service life of the device. Through the stiffness verification stage, a virtual load is applied to the motor 6 mounting position for vibration simulation, and the maximum displacement is controlled to be less than a predetermined threshold, thereby ensuring that the device has sufficient stiffness, avoiding excessive deformation due to load, and ensuring the stability and reliability of the test process. Through iterative execution, modal verification and stiffness verification are combined, and the model is repeatedly modified until both frequency and displacement requirements are met, improving the robustness and performance of the device. Through virtual testing and parameter adjustment, the structural dynamic characteristics of the testing device are optimized, making the vibration test results more realistically reflect the actual operating state of the range hood, improving the reliability of the test data. The designed range hood vibration testing device can simulate the vibration of the range hood during operation, reducing the influence of resonance and forced vibration.
[0029] As an optional implementation, step S3 above modifies the current finite element model according to a preset first modification scheme, including: Determine the mode shape corresponding to the natural frequency within the preset excitation frequency range of motor 6; In the region of maximum vibration displacement in the mode shape, reinforce the structure and / or increase the thickness of the plate.
[0030] Based on the aforementioned embodiments, in this embodiment, the mode shape is a distribution diagram of the relative amplitude of various points on the testing device when the testing device vibrates at a certain natural frequency. Each natural frequency corresponds to a unique mode shape, which reveals the displacement distribution of the testing device when vibrating at that frequency. The mode shape describes "how the testing device moves," while the natural frequency describes "how fast it moves." The mode shape is obtained through simulation. The region with the largest displacement in the mode shape is the region with the weakest stiffness and the most frequency sensitivity at that mode. This region needs to be "strengthened" by increasing the stiffness through structural reinforcement and / or increasing the thickness of the plate, thereby changing (raising) the natural frequency of that mode. The strengthening structure can be a stiffening rib.
[0031] As an optional implementation, the vibration simulation in step S4 above, which involves applying a preset virtual load at the mounting position of the motor 6, includes applying three loads with preset directions and preset proportions at the mounting position of the motor 6.
[0032] When motor 6 is working, the force generated by its vibration is not unidirectional. It is a complex force existing in three-dimensional space. In order to realistically reproduce this state in the simulation, it is simplified into component forces in three main directions.
[0033] As an optional implementation, the preset direction is configured as three mutually perpendicular directions; the preset ratio is configured as (1.5-2.5):(1.5-2.5):(5.5-6.5).
[0034] Based on the aforementioned embodiments, in this embodiment, by simultaneously applying loads in three mutually perpendicular directions, this composite stress state can be simulated more realistically, making the stiffness verification conditions closer to reality. These three directions are typically three mutually perpendicular (orthogonal) axes: the X-axis in the front-to-back direction, the Y-axis in the left-to-right direction, and the Z-axis in the up-down direction. The most significant component of the vibration of the range hood motor 6 is in the up-down direction (Z-axis). Therefore, the load on the Z-axis is the largest, while the loads in the front-to-back direction (X-axis) and the left-to-right direction (Y-axis) are relatively small.
[0035] As an optional implementation method, the preset ratio is configured as 2:2:6.
[0036] Based on the aforementioned embodiments, in this embodiment, a force of 60 Newtons is applied along the Z-axis, and a force of 20 Newtons is applied along both the X-axis and Y-axis.
[0037] As an optional implementation, step S5 above modifies the current finite element model according to a preset second modification scheme, including: Obtain the displacement contour plot after vibration simulation; In areas where the displacement in the displacement cloud map is greater than or equal to a predetermined threshold, reinforced structures and / or plate thickness are added.
[0038] Based on the aforementioned embodiments, in this embodiment, the displacement contour map is a color-coded map indicating "where the deformation is large and where the deformation is small" after being subjected to force. By viewing the maximum displacement value on the contour map and comparing it with a predetermined threshold, it can be directly determined whether the stiffness verification has passed. If it has not passed, the area with large displacement is a "weak point" with insufficient stiffness. Strengthening this area by adding reinforcing structures and / or increasing the thickness of the plate material reduces local deformation and thus improves the overall structural stiffness. The reinforcing structure refers to stiffening ribs.
[0039] As an optional implementation, the predetermined threshold is 0.1 mm.
[0040] In vibration testing, the deformation of the testing device itself can contaminate the true vibration signal of the motor under test 6. By limiting the displacement of the motor 6 mounting point to an extremely small order of magnitude (i.e., 0.1 mm), the impact of the minute deformation on the measurement accuracy can be ignored, eliminating the measurement error caused by the deformation of the testing device itself, and ensuring that the vibration sensor collects the true vibration performance of the motor 6 itself.
[0041] like Figure 2-7 As shown, based on the same inventive concept, this application provides a design method for a range hood vibration testing device according to any of the foregoing embodiments. The resulting range hood vibration testing device mainly includes a fan housing 1, a housing 2, a mounting base 3, detachably connected side baffles 4 and detachably connected bottom baffles 5. An air duct is formed inside the fan housing 1, and an air outlet 21 is located at the top of the fan housing 1. The housing 2 has a cavity inside, and the fan housing 1 is installed within the cavity. An air outlet 21 communicating with the air duct is opened on the top wall of the housing 2, and air outlets 21 are opened on the side walls of the housing 2. The device is provided with a first air inlet 22 connected to the air duct, and a second air inlet 23 connected to the air duct is provided on the bottom wall of the housing 2. The mounting base 3 is fixed inside the air cabinet 1 and is used to install the motor 6 under test. A detachable side baffle 4 is used to close the first air inlet 22. A detachable bottom baffle 5 is used to close the second air inlet 23. In the first test state, the side baffle 4 is fixed to the side wall of the housing 2 and the bottom baffle 5 is separated from the bottom wall of the housing 2. In the second test state, the bottom baffle 5 is fixed to the bottom wall of the housing 2 and the side baffle 4 is separated from the side wall of the housing 2.
[0042] Based on the aforementioned embodiments, in this embodiment, the outer shell 2 is a box, and the shell wall of the outer shell 2 forms a cavity. A vertically extending air outlet 21 is opened on the top wall of the outer shell 2. The air handling unit 1 is volute-shaped and fixed within the cavity. The mounting base 3 is fixed inside the air handling unit 1, so that the fan installed on the mounting base 3 is also located inside the air handling unit 1.
[0043] The range hood vibration testing device provided in this application embodiment, through detachable side baffles 4 and bottom baffles 5, clearly defines two test states: side air intake and bottom air intake, becoming a multi-functional testing platform that eliminates the need for separate design and manufacture of dedicated testing fixtures for each test scenario. This greatly improves the convenience of testing and the utilization rate of the equipment. The motor under test 6 is installed on the mounting base 3 inside the fan housing 1, which can reflect the actual vibration state of the motor 6 under the action of air duct, air pressure, etc., making the test data closer to the actual working condition of the range hood, and the test results more accurate and reliable. In addition, the detachable connection between the motor 6 and the fan housing 1 separates the motor 6 under test from the fan housing 1, isolating interference factors, so that the test results purely reflect the vibration characteristics of the motor 6 itself. The testing device is obtained based on the aforementioned design method, which prevents the testing device itself from experiencing severe resonance or excessive deformation, thereby avoiding interference from the vibration of the testing device itself on the measurement results and ensuring the stability of the testing process.
[0044] As an optional implementation, the mounting base 3 includes multiple support columns 31 and multiple mounting plates 32; the multiple support columns 31 are distributed circumferentially and their first ends are fixed to the air handling unit 1; the multiple mounting plates 32 are detachably connected to the second ends of the multiple support columns 31, and the mounting plates 32 have multiple mounting holes arranged circumferentially; the diameters of the distribution circles of the mounting holes of the multiple mounting plates 32 are different to accommodate motors 6 of different specifications.
[0045] Based on the foregoing embodiments, in this embodiment, the support column 31 and the mounting plate 32 are detachably connected. The support column 31 provides sufficient support for the mounting plate 32. The mounting plate 32 is the mounting position of the motor 6 in the aforementioned design method and is a key point where the maximum displacement needs to be determined. One mounting plate 32 corresponds to one size of motor 6. By replacing different mounting plates 32, motors 6 of different sizes and mounting specifications can be quickly adapted, greatly expanding the application range of the testing device.
[0046] As an alternative implementation, the bottom wall of the outer casing 2 extends in opposite directions to form an extension plate 24; a plurality of reinforcing plates 25 are spaced apart on the extension plate 24 and connected to the side wall of the outer casing 2.
[0047] Based on the aforementioned embodiments, in this embodiment, the bottom wall is extended to both sides to form extension plates 24, which improves the structural bending stiffness. A reinforcing plate 25 is added between the extension plate 24 and the sidewalls, dividing the large-area shell structure into multiple smaller regions, greatly improving local stiffness and stability, and suppressing local deformation and vibration. This reinforcement method also helps to raise the structure's lower-order natural frequencies, making it easier to avoid the excitation frequency range.
[0048] In some embodiments, the range hood vibration testing device is made of aluminum plate.
[0049] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.
[0050] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.
[0051] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0052] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.
[0053] It should be understood that although the steps in the flowcharts of the accompanying figures are shown sequentially as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the accompanying figures may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the sub-steps or stages of other steps.
[0054] The above description is only a partial embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.
Claims
1. A design method for a vibration testing device for a range hood, characterized in that, include: Construct a finite element model of the target range hood vibration testing device; Determine whether all natural frequencies of the finite element model are outside the preset motor (6) excitation frequency range; If any natural frequency is within the preset motor (6) excitation frequency range, the current finite element model is modified according to the preset first modification scheme until all natural frequencies of the current finite element model are outside the preset motor (6) excitation frequency range, so as to pass the modal verification stage. For the finite element model that has passed the modal verification stage, a preset virtual load is applied at the motor (6) mounting position to perform vibration simulation, and the maximum displacement of the motor (6) mounting position is confirmed. If the determined maximum displacement is greater than or equal to the predetermined threshold, the current finite element model is modified according to the preset second modification scheme until the maximum displacement of the motor (6) installation position of the current finite element model is less than the predetermined threshold, so as to pass the stiffness verification stage and repeat the modal verification stage. The modal verification stage and stiffness verification stage are executed iteratively until all natural frequencies of the latest finite element model are outside the preset motor (6) excitation frequency range and the maximum displacement of the motor (6) installation position of the finite element model is less than the predetermined threshold.
2. The design method of the range hood vibration testing device according to claim 1, characterized in that, Modify the current finite element model according to the preset first modification scheme, including: Determine the mode shape corresponding to the natural frequency within the preset excitation frequency range of the motor (6); In the region of maximum vibration displacement in the vibration mode, reinforce the structure and / or increase the thickness of the plate.
3. The design method of the range hood vibration testing device according to claim 1, characterized in that, Vibration simulation is performed by applying a preset virtual load at the motor (6) mounting location, including: Three loads with preset directions and preset proportions are applied at the motor (6) mounting position.
4. The design method of the range hood vibration testing device according to claim 3, characterized in that, The preset direction is configured as three mutually perpendicular directions; The preset ratio is configured as (1.5-2.5):(1.5-2.5):(5.5-6.5).
5. The design method of the range hood vibration testing device according to claim 4, characterized in that, The preset ratio is configured as 2:2:
6.
6. The design method of the range hood vibration testing device according to claim 1, characterized in that, Modify the current finite element model according to the preset second modification scheme, including: Obtain the displacement contour plot after vibration simulation; In the region of the displacement cloud map where the displacement is greater than or equal to the predetermined threshold, a reinforcing structure is added and / or the plate thickness is increased.
7. The design method of the range hood vibration testing device according to claim 1, characterized in that, The predetermined threshold is 0.1 mm.
8. A range hood vibration testing device designed using the design method of any one of claims 1-7, characterized in that, include: The air handling unit (1) has an internal air duct. The outer shell (2) has a cavity inside, the air cabinet (1) is installed in the cavity, the top wall of the outer shell (2) has an air outlet (21) communicating with the air duct, the side wall of the outer shell (2) has a first air inlet (22) communicating with the air duct, and the bottom wall of the outer shell (2) has a second air inlet (23) communicating with the air duct. Mounting base (3) is fixed inside the air handling unit (1) and is used to install the motor (6) to be tested. A detachable side baffle (4) is used to close the first air inlet (22). A detachable bottom baffle (5) is used to close the second air inlet (23); In the first test state, the side baffle (4) is fixed to the side wall of the outer shell (2), and the bottom baffle (5) is separated from the bottom wall of the outer shell (2); in the second test state, the bottom baffle (5) is fixed to the bottom wall of the outer shell (2), and the side baffle (4) is separated from the side wall of the outer shell (2).
9. The range hood vibration testing device according to claim 8, characterized in that, The mounting base (3) includes: Multiple support pillars (31) are distributed circumferentially and their first ends are fixed to the air handling unit (1); Multiple mounting plates (32) are detachably connected to the second end of the multiple support columns (31). The mounting plates (32) have multiple mounting holes arranged circumferentially. The diameters of the mounting hole distribution circles of the multiple mounting plates (32) are different to accommodate motors (6) of different specifications.
10. The range hood vibration testing device according to claim 8 or 9, characterized in that, The bottom wall of the outer shell (2) extends in opposite directions to form an extension plate (24). Multiple reinforcing plates (25) are spaced apart on the extension plate (24) and connected to the sidewall of the outer shell (2).