A cover noise reduction design method, device, equipment, medium and program product

Abstract

The application discloses a cover shell noise reduction design method, device, equipment, medium and program product, and relates to the technical field of device simulation and structure optimization. The method comprises the following steps: a dynamic model of an internal mechanism of a sewing device is established, and a transient time domain exciting force is extracted; the frequency domain exciting load of the transient time domain exciting force is taken as an excitation boundary condition, and is applied to a numerical analysis model of the cover shell; based on the numerical analysis model, a sound pressure level peak value is extracted, and a vibration energy concentration area corresponding to the sound pressure level peak value is determined; a cover shell panel part corresponding to the vibration energy concentration area is taken as a target object, structure characteristics of the target object are updated under the condition of manufacturability constraints, an optimized cover shell geometric model is generated, and the cover shell geometric model is iteratively verified until the acoustic response meets a preset noise reduction requirement. The above technical feature realizes precise noise reduction, efficient design and manufacturable optimization closed loop of the cover shell of the high-speed overlock machine.

Description

Technical Field

[0001] This invention relates to the field of equipment simulation and structural optimization technology, and in particular to a method, device, equipment, medium and program product for noise reduction design of a housing. Background Technology

[0002] As a high-frequency sewing machine, the spindle speed of an overlock sewing machine often reaches 6000 RPM or even higher. Under high-speed operation, the alternating inertial force and periodic impact of the internal mechanism are amplified sharply, which excites high-frequency modal resonance of the machine casing and generates strong outward radiated noise, seriously affecting the hearing health of operators and the high-end experience of the product.

[0003] Currently, the industry's design for vibration reduction and noise reduction of ultra-high speed overlock sewing machines often faces problems such as difficulty in extracting high-frequency dynamic loads with high fidelity, high cost of calculating high-frequency acoustic response, and lack of systematic and manufacturable closed-loop design in traditional noise reduction. Summary of the Invention

[0004] This invention provides a noise reduction design method, device, equipment, medium, and program product for a cover, achieving a closed loop of precise noise reduction, efficient design, and manufacturability optimization for the cover of a high-speed overlock sewing machine.

[0005] In a first aspect, embodiments of the present invention provide a noise reduction design method for a housing, comprising: A dynamic model of the internal mechanism of the sewing equipment is established, and the transient time-domain excitation force at the coupling node between the internal mechanism and the cover under the set working conditions is extracted. The frequency-domain excitation load corresponding to the transient time-domain excitation force is used as the excitation boundary condition for forced vibration and applied to the numerical analysis model of the housing. Based on the numerical analysis model, the acoustic response of the enclosure radiating outward is determined, the peak sound pressure level is extracted, and the vibration energy concentration area corresponding to the peak sound pressure level is determined. The shell panel corresponding to the area where the vibration energy is concentrated is taken as the target object. Under the manufacturability constraint, the structural features of the target object are updated to generate an optimized shell geometric model. The shell geometric model is then iteratively verified until the acoustic response meets the preset noise reduction requirements.

[0006] Secondly, embodiments of the present invention provide a noise reduction design device for a housing, comprising: The excitation force extraction module is used to establish a dynamic model of the internal mechanism of the sewing equipment and extract the transient time-domain excitation force at the coupling node between the internal mechanism and the cover under the set working conditions. The boundary condition application module is used to apply the frequency domain excitation load corresponding to the transient time domain excitation force as the excitation boundary condition for forced vibration to the numerical analysis model of the cover. The region determination module is used to determine the acoustic response radiated outward by the enclosure based on the numerical analysis model, extract the peak sound pressure level, and determine the vibration energy concentration area corresponding to the peak sound pressure level. The geometry optimization module is used to take the shell panel part corresponding to the vibration energy concentration area as the target object, update the structural features of the target object under manufacturability constraints, generate an optimized shell geometry model, and iteratively verify the shell geometry model until the acoustic response meets the preset noise reduction requirements.

[0007] Thirdly, embodiments of the present invention provide an electronic device, including: At least one processor; and A memory that is communicatively connected to at least one processor; wherein, The memory stores a computer program that can be executed by at least one processor, such that the at least one processor is able to execute the casing noise reduction design method provided in the first aspect embodiment described above.

[0008] Fourthly, embodiments of the present invention provide a computer-readable storage medium storing computer instructions that are used to cause a processor to execute and implement the casing noise reduction design method provided in the first aspect of the embodiments described above.

[0009] Fifthly, embodiments of the present invention provide a computer program product, the computer program product including a computer program, which, when executed by a processor, implements a casing noise reduction design method provided in the first aspect embodiment above.

[0010] The technical solution of this invention establishes a dynamic model of the internal mechanism of the sewing equipment, extracts the transient time-domain excitation force at the coupling node between the internal mechanism and the cover under a set working condition; applies the frequency-domain excitation load corresponding to the transient time-domain excitation force as the excitation boundary condition for forced vibration to the numerical analysis model of the cover; based on the numerical analysis model, determines the acoustic response radiated outward by the cover, extracts the peak sound pressure level, and determines the vibration energy concentration area corresponding to the peak sound pressure level; takes the cover panel part corresponding to the vibration energy concentration area as the target object, updates the structural features of the target object under manufacturability constraints, generates an optimized cover geometric model, and iteratively verifies the cover geometric model until the acoustic response meets the preset noise reduction requirements. The aforementioned technical features, by obtaining transient time-domain excitation force through a dynamic model rather than relying on direct physical measurement, solve the problem of high-fidelity extraction of excitation force under high-frequency conditions, providing accurate excitation input for subsequent acoustic analysis; transforming acoustic response analysis from the time domain to the frequency domain significantly reduces computational costs compared to the full-space boundary element or finite element methods; using spatial field point sound pressure level as an evaluation index to replace pure structural vibration index, truly reflecting the noise perception at the operator's ear position, while providing a clear direction for optimization; forming a positive design closed loop from excitation extraction to optimization verification, while ensuring that the optimization results can be directly used for production and manufacturing, overcoming the problems of traditional reliance on experience-based trial and error and the disconnect between optimized structure and process.

[0011] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a flowchart of a noise reduction design method for a housing provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of a complete overlock sewing machine model provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of a partial model of a spindle drive module provided in an embodiment of the present invention; Figure 4 This is a comparison diagram of the surface velocity of a cover provided in an embodiment of the present invention; Figure 5 This is a comparison diagram of a sound pressure level cloud map provided in an embodiment of the present invention; Figure 6 This is a comparison diagram of a casing provided in an embodiment of the present invention; Figure 7 This is a comparison diagram of a sound pressure level frequency response curve provided in an embodiment of the present invention; Figure 8 This is a schematic diagram of the structure of a noise reduction design device for a housing provided in an embodiment of the present invention; Figure 9 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0014] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0015] 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 apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0016] Traditional analyses often treat linkage mechanisms as rigid bodies, neglecting the elastic deformation (flexibility) of components at 6000 RPM and the transient impact when a cutter cuts fabric. This leads to distorted excitation forces and an inability to accurately capture high-order harmonic excitations that cause high-frequency noise. If traditional acoustic boundary element method (BEM) or finite element method (FEM) is used to calculate broadband radiated noise of several kilohertz, the mesh size is enormous and the computation time is lengthy, making it difficult to support subsequent rapid iterative optimization. In addition, existing technologies often rely on engineers' experience to trial and error on the casing to assemble stiffeners. This blind trial and error method is not only time-consuming but also often only improves low-frequency stiffness and cannot effectively suppress high-frequency resonance. At the same time, the biomimetic structures generated by pure topology optimization often fail to meet the mold-making process requirements of cast aluminum or thin-walled injection molding.

[0017] Existing technologies struggle to form a complete technological closed loop, resulting in long development cycles and high costs for noise reduction research and development of high-speed overlock sewing machines. Therefore, this invention provides a noise reduction design scheme for overlock sewing machine casings based on transient dynamic load extraction, addressing the problems of inaccurate prediction of overall machine radiated noise under high-speed operating conditions and low efficiency of forward optimization design.

[0018] In one embodiment, Figure 1 This is a flowchart of a noise reduction design method for a cover provided by an embodiment of the present invention. This embodiment can be applied to the noise reduction design of a sewing machine cover based on transient dynamic load extraction and acoustic-vibration coupling optimization. The method can be executed by a cover noise reduction design device, which can be implemented in hardware and / or software.

[0019] like Figure 1 As shown, the method includes: S101. Establish a dynamic model of the internal mechanism of the sewing equipment and extract the transient time-domain excitation force at the coupling node between the internal mechanism and the cover under the set working conditions.

[0020] Figure 2 This is a schematic diagram of a complete overlock sewing machine model provided in an embodiment of the present invention. Figure 3 This is a schematic diagram of a partial model of a spindle drive module provided in an embodiment of the present invention. Figure 2 and Figure 3The diagram illustrates the overall structure of an overlock sewing machine, a type of sewing equipment described in this embodiment of the invention. The overlock sewing machine includes an internal mechanism and a housing. The internal mechanism comprises at least a main shaft drive module, a seam-forming execution module, and a cutting mechanism. The housing covers the exterior of the internal mechanism and constitutes the main structure for noise radiation. The core operating components that generate high-frequency transient excitation are mainly distributed in the main shaft drive module (including an eccentric wheel and connecting rod) and the seam-forming execution module (upper looper, lower looper, and needle bar). The resulting structural vibrations are ultimately transmitted to the metal / plastic composite housing assembly and the thin-walled outer housing, causing noise to radiate into the air.

[0021] In this embodiment, the sewing equipment can be understood as industrial sewing equipment such as overlock machines and coverstitch machines that have high-speed reciprocating motion mechanisms and require noise suppression through a casing. The internal mechanism can be understood as the assembly of moving parts inside the sewing equipment that participate in high-speed reciprocating motion and generate alternating inertial forces and periodic impacts, including the spindle drive module (including eccentric wheels and connecting rods), the stitch-forming execution module (including upper looper, lower looper, and needle bar), and the cutting mechanism. The dynamic model can be understood as a mathematical model established using multibody dynamics simulation software to describe the motion state and force relationships of the internal mechanism of the overlock machine. This model defines the connecting rods and looper components with large slenderness ratios as flexible bodies to reflect the elastic deformation of the components themselves under high-speed operation. The set operating conditions can be understood as the combination of operating parameters of the overlock machine under specific working conditions, including spindle speed, load conditions, and sewing speed. The transient time-domain excitation force at the coupling node between the internal mechanism and the casing can be understood as the dynamic force that changes with time and is transmitted to the casing through each bearing seat and fixed hinge point when the internal mechanism is running at high speed under set working conditions. This force includes the periodic harmonic components generated by the operation of the internal mechanism and the impact load components of the cutter.

[0022] Specifically, due to the significant elastic deformation of the long, slender connecting rods and bent needle components during high-speed operation of the internal mechanism, they need to be treated as flexible bodies to construct a rigid-flexible coupling model, thereby accurately describing the motion and stress state of each component. Based on this, simulation is performed using the spindle speed as the drive input to extract the three-dimensional transient time-domain excitation forces at the bearing seats and fixed hinge points of the internal mechanism and the housing. These transient time-domain excitation forces simultaneously reflect the high-frequency harmonics generated by the periodic motion and the transient impact when the cutter contacts the fabric.

[0023] S102. The frequency-domain excitation load corresponding to the transient time-domain excitation force is applied as the excitation boundary condition for forced vibration to the numerical analysis model of the casing.

[0024] In this embodiment, the frequency-domain excitation load corresponding to the transient time-domain excitation force can be understood as the excitation force spectrum with frequency as the horizontal axis obtained by frequency-domain transformation of the extracted time-domain force signal. The spectrum amplitude reflects the energy distribution characteristics of the excitation force at different frequency components. The excitation boundary conditions of forced vibration can be understood as the loading method of applying the frequency-domain excitation load to the corresponding nodes of the shell numerical analysis model, so that the model can simulate the dynamic excitation transmitted from the internal mechanism to the shell under actual working conditions in the subsequent frequency response analysis. The numerical analysis model of the shell can be understood as a finite element model built in a computer to characterize the geometry, material properties, and boundary conditions of the shell.

[0025] Specifically, transient time-domain excitation forces cannot be directly used for vibration and acoustic response analysis in the frequency domain. Therefore, the extracted transient time-domain excitation force must first undergo a frequency domain transformation to be converted into a frequency-domain excitation load. This frequency-domain excitation load is then used as the excitation boundary condition for frequency response analysis, and is precisely loaded onto the corresponding nodes of the shell numerical analysis model using a spatial mapping algorithm. Spatial mapping refers to applying the frequency-domain load at each hinge point to the nodes in the finite element mesh corresponding to the actual hinge point positions. Since the numerical analysis model is a finite element model, its discretized mesh nodes are the direct load-bearing bodies. By applying the frequency-domain load to the nodes corresponding to the actual hinge point positions, the accuracy of the load transfer path can be ensured. The frequency domain transformation can employ the Fast Fourier Transform algorithm.

[0026] S103. Based on the numerical analysis model, determine the acoustic response of the enclosure radiating outward, extract the peak sound pressure level, and determine the vibration energy concentration area corresponding to the peak sound pressure level.

[0027] In this embodiment, acoustic response can be understood as the sound pressure distribution in space of audible sound waves radiated outward by compressing the surrounding air medium when the shell surface is subjected to forced vibration. The peak sound pressure level (SPL) can be understood as the highest value of the SPL frequency response curve at the target spatial point within a set frequency band; the frequency corresponding to the peak is the primary resonant frequency, which is the main cause of excessive noise. The vibration energy concentration area can be understood as a local shell surface where the normal vibration velocity amplitude of the shell surface is significantly higher than other areas under the excitation of this resonant frequency; this vibration energy concentration area is the main structural part radiating noise outward.

[0028] Specifically, after applying the frequency domain load, a frequency response analysis is first performed based on the numerical analysis model to determine the normal vibration velocity of each node on the shell surface at different frequencies. Then, based on the fluid-structure interaction boundary conditions, the sound pressure level radiated outward from the shell to the target spatial point (such as the operator's ear position) is calculated using the normal vibration velocity as input, obtaining the frequency response curve of the sound pressure level as a function of frequency. Finally, the peak sound pressure level and its corresponding frequency are extracted from the frequency response curve, and the region with the largest amplitude of the normal vibration velocity on the shell surface is located in the vibration response results at that frequency as the region of concentrated vibration energy.

[0029] S104. Take the cover panel part corresponding to the area where the vibration energy is concentrated as the target object. Under the manufacturability constraint, update the structural features of the target object, generate the optimized cover geometric model, and iteratively verify the cover geometric model until the acoustic response meets the preset noise reduction requirements.

[0030] In this embodiment, the target object can be understood as the shell panel corresponding to the area of ​​concentrated vibration energy, i.e., the specific shell surface area that needs structural optimization. The geometric characteristics of this area directly determine the local stiffness and vibration amplitude of the shell in this frequency band. Manufacturability constraints can be understood as limiting parameters imposed to ensure that the optimized structure can be manufactured through actual production processes, including setting the draft direction (to ensure smooth removal from the mold after molding), minimum undulation width (to ensure that the reinforcing ribs or calendering grooves can be actually formed), and maximum undulation height (to avoid excessive stretching leading to material cracking or molding defects). Structural characteristics can be understood as the surface geometry of the shell panel, including its local concave and convex shapes, reinforcing rib layout, and undulation shape. Changes in these characteristics directly affect the local stiffness distribution and vibration transmission path of the shell, thereby changing the outward radiated sound pressure level.

[0031] Specifically, after identifying the concentrated vibration energy region, the corresponding enclosure panel is first designated as the target object. Then, using draft direction, minimum undulation width, and maximum undulation height as constraints, morphology optimization and / or topology optimization algorithms are employed to automatically modify the surface geometry of the target object by disturbing node coordinates along the surface normal or optimizing material distribution. This generates new reinforcing ribs or calendering groove layouts to reduce the peak sound pressure level at the target spatial point. After generating the optimized enclosure geometry model based on the modified surface geometry, the acoustic response verification steps S102 to S103 are re-executed to evaluate the actual noise reduction effect of the optimization scheme. If the reduction in the current peak sound pressure level compared to the initial peak does not reach the preset reduction threshold, optimization and verification are performed again based on the current model, iterating until the reduction reaches the preset threshold, thus completing the noise reduction design loop.

[0032] The present invention provides a noise reduction design method for a housing, comprising: establishing a dynamic model of the internal mechanism of a sewing equipment; extracting the transient time-domain excitation force at the coupling node between the internal mechanism and the housing under a set working condition; applying the frequency-domain excitation load corresponding to the transient time-domain excitation force as the excitation boundary condition for forced vibration to the numerical analysis model of the housing; determining the acoustic response radiated outward by the housing based on the numerical analysis model, extracting the peak sound pressure level, and determining the vibration energy concentration area corresponding to the peak sound pressure level; taking the housing panel part corresponding to the vibration energy concentration area as the target object, updating the structural features of the target object under manufacturability constraints, generating an optimized housing geometric model, and iteratively verifying the housing geometric model until the acoustic response meets the preset noise reduction requirements. The aforementioned technical features, by obtaining transient time-domain excitation force through a dynamic model rather than relying on direct physical measurement, solve the problem of high-fidelity extraction of excitation force under high-frequency conditions, providing accurate excitation input for subsequent acoustic analysis; transforming acoustic response analysis from the time domain to the frequency domain significantly reduces computational costs compared to the full-space boundary element or finite element methods; using spatial field point sound pressure level as an evaluation index to replace pure structural vibration index, truly reflecting the noise perception at the operator's ear position, while providing a clear direction for optimization; forming a positive design closed loop from excitation extraction to optimization verification, while ensuring that the optimization results can be directly used for production and manufacturing, overcoming the problems of traditional reliance on experience-based trial and error and the disconnect between optimized structure and process.

[0033] As a first optional embodiment of this example, a dynamic model of the internal mechanism of the sewing equipment is established, and the transient time-domain excitation force at the coupling node between the internal mechanism and the casing under a set working condition is extracted, including: S1011. Determine the connecting rods and bent needle components with a slenderness ratio greater than a preset threshold in the internal mechanism as flexible bodies, and establish a rigid-flexible coupled multibody dynamics model of the internal mechanism.

[0034] In this embodiment, the slenderness ratio can be understood as the ratio of the length of a connecting rod or bent needle component to its cross-sectional radius of gyration. When this ratio exceeds a preset threshold, the elastic deformation (such as bending and stretching) of the component along its length under high-speed operation cannot be ignored. Treating it as a rigid body will lead to distortion in the calculation of excitation force; therefore, it needs to be determined as a flexible body. A flexible body can be understood as a deformable body that, in addition to having mass and inertia, also possesses elastic deformation capabilities in dynamic simulation. Its deformation is described by modal superposition or finite element discretization. The rigid-flexible coupled multibody dynamics model can be understood as a multibody dynamics model that simultaneously includes rigid and flexible components. This model can simultaneously solve the overall motion of the rigid component and the elastic deformation of the flexible component, thereby describing the actual motion state and force conditions of the internal mechanism under high-speed operation.

[0035] Specifically, when establishing a rigid-flexible coupled multibody dynamics model of the internal mechanism of the sewing equipment, the connecting rods and bending needles that need to be defined as flexible bodies are first selected based on the slenderness ratio of each component. Then, modal analysis or finite element discretization is performed on the flexible body component to extract its natural frequencies and mode shapes, which are used to describe its elastic deformation during motion. Finally, the flexible body component is assembled with the remaining rigid body components through kinematic pairs such as hinges and sliding joints to form a complete rigid-flexible coupled multibody dynamics model.

[0036] The rigid-flexible coupled multibody dynamics model constructed in this embodiment considers the influence of component elastic deformation on the load transmission path, and can accurately capture the periodic harmonic excitation force and cutter impact load generated by the high-speed motion of the internal mechanism.

[0037] S1012. Using the spindle speed under the set working conditions as the drive input, run the rigid-flexible coupling multibody dynamics simulation.

[0038] In this embodiment, the spindle speed under the set working condition can be understood as the rotational speed of the spindle of the overlock sewing machine under a specific working state, usually measured in revolutions per minute (RPM). This speed is the driving source of all motion mechanisms inside the overlock sewing machine, and determines the motion frequency and amplitude of each mechanism.

[0039] Specifically, the spindle speed under the set operating conditions is converted into a time-varying spindle rotation drive function (including angular displacement, angular velocity, and angular acceleration), and this function is used as the boundary condition for the rigid-flexible coupled multibody dynamics model. This boundary condition is applied to the spindle drive end of the model to drive the internal mechanism to move according to the preset operating conditions. Then, the start and end times and time step of the simulation analysis are set to cover multiple complete cycles of spindle rotation to fully capture periodic signals and transient impacts. Finally, the simulation solution is submitted. This simulation process simultaneously solves for the overall motion trajectory of the rigid components and the elastic deformation response of the flexible components, outputting the constraint reaction forces at each kinematic pair of the internal mechanism and the contact forces between the components.

[0040] S1013. Extract the three-dimensional transient time-domain excitation force at each bearing seat and fixed hinge point of the internal mechanism and the housing. The transient time-domain excitation force includes the periodic harmonic components generated by the operation of the internal mechanism and the impact load components of the cutter.

[0041] In this embodiment, the bearing housing can be understood as the bearing mounting seat in the internal mechanism of the overlock sewing machine used to support the main shaft and transmission shaft. The fixed hinge point can be understood as the fixed hinge position between each connecting rod of the internal mechanism and the machine housing connected by a pin. The above position is the main path node for the transmission of vibration energy of the internal mechanism to the housing. The three-dimensional transient time-domain excitation force can be understood as a dynamic force signal that varies with time along the three orthogonal directions of X, Y, and Z in the global coordinate system, including periodic harmonic components and cutter impact load components. The periodic harmonic component can be understood as a periodic alternating force component generated by the reciprocating motion of the mechanism driven by the uniform rotation of the main shaft, with the main shaft fundamental frequency and its integer multiples of frequency (i.e., higher-order harmonics) as characteristic frequencies. The cutter impact load component can be understood as the transient sudden impact force component generated by the cutter during the contact and separation when cutting the fabric. This component is manifested in the time domain as an impact pulse signal with extremely short duration, a sharp increase in amplitude, and rapid decay.

[0042] Specifically, after completing the rigid-flexible coupling multibody dynamics simulation, the triaxial constraint reaction force or contact force data at each bearing housing and fixed hinge point within a set time period are extracted from the simulation results to obtain the triaxial transient time-domain excitation force. The triaxial transient time-domain excitation force simultaneously includes the periodic harmonic components (i.e., excitations of each order) generated by the periodic reciprocating motion of the mechanism driven by the uniform rotation of the spindle, and the transient sudden impact load generated by the material shearing fracture when the cutter contacts the fabric. The transient time-domain excitation force reflects the complete dynamic excitation borne by the housing under actual working conditions.

[0043] As a second optional embodiment of this example, the frequency-domain excitation load corresponding to the transient time-domain excitation force is used as the excitation boundary condition for forced vibration and applied to the numerical analysis model of the casing, including: S1021. Perform frequency domain transformation on the transient time-domain excitation force to obtain the frequency-domain excitation load.

[0044] In this embodiment, the extracted triaxial transient time-domain excitation forces at each bearing housing and fixed hinge point are subjected to frequency domain transformation, converting them from time-domain signals to frequency-domain signals. The frequency domain transformation can be implemented using the Fast Fourier Transform algorithm. The time-domain excitation force signal is decomposed into a superposition of multiple frequency components, thereby obtaining the amplitude and phase information corresponding to each frequency point. It is a transient time-domain excitation force signal. For time variables, For frequency domain excitation load, It is the angular frequency (unit: radians / second), used to capture the spindle fundamental frequency (e.g., 100Hz for 6000RPM) and its higher-order harmonic components (e.g., order excitation in the 1000Hz-2000Hz frequency band). The imaginary unit is i = -1. After the transformation, the frequency domain excitation load with each bearing housing and the fixed hinge point position as the carrier is obtained.

[0045] S1022. The frequency domain excitation load is used as the excitation boundary condition for forced vibration and spatially mapped to the corresponding nodes of the numerical analysis model of the shell. The numerical analysis model is a finite element model.

[0046] In this embodiment, the excitation boundary conditions can be understood as external dynamic excitation inputs applied to the numerical analysis model to drive the model to generate corresponding vibration responses. The finite element model can be understood as a numerical calculation model established by discretizing the continuous shell structure into a finite number of elements and nodes, where each node is the direct load-bearing body. The overall vibration response of the shell can be obtained by solving the dynamic equilibrium equations at the nodes.

[0047] Specifically, the frequency-domain excitation loads at each hinge point are mapped one by one to the corresponding nodes of the finite element model of the casing. These nodes are finite element nodes in the casing's finite element mesh that have the same spatial location as the hinge points in the multibody dynamics model. Then, each frequency-domain excitation load is applied as the excitation boundary condition for frequency response analysis to the corresponding node, enabling the model to simulate the dynamic excitation transmitted from the internal mechanism to the casing through the bearing housing and fixed hinge points under actual working conditions in subsequent analyses.

[0048] As a third optional embodiment of this example, based on a numerical analysis model, the acoustic response radiated outward from the enclosure is determined, the peak sound pressure level is extracted, and the vibration energy concentration region corresponding to the peak sound pressure level is determined, including: S1031. Based on the numerical analysis model with applied excitation boundary conditions, frequency response analysis is performed to obtain the normal vibration velocity on the surface of the casing.

[0049] In this embodiment, the normal vibration velocity can be understood as the vibration velocity component of each node on the surface of the cover along its outer normal direction. Only the vibration component perpendicular to the surface of the cover can effectively compress the surrounding air medium and radiate sound waves outward.

[0050] Specifically, based on the numerical analysis model with applied frequency-domain excitation load, corresponding harmonic excitations are applied one by one at each frequency point within a set frequency band. The finite element solver is called through the Radiated Acoustic Analysis Module (RADSND) to perform frequency response analysis on the shell structure, calculate the steady-state vibration response of the shell structure in the frequency domain, obtain the vibration displacement, velocity, and acceleration responses of each node on the shell surface at different frequencies, and extract the normal vibration velocity components of each node on the shell surface. .

[0051] S1032. Based on the normal vibration velocity, determine the sound pressure level radiated outward from the cover to the target space field point, and obtain the sound pressure level frequency response curve.

[0052] The target spatial field point includes the operator's ear position.

[0053] In this embodiment, the target spatial field point can be understood as a specific spatial location in the sound field used to evaluate the sound pressure level. This location can be flexibly set according to actual noise reduction needs, such as the operator's ear position (used to assess the impact of noise on the operator's hearing health) or a far-field location in a specific direction around the equipment (used to assess the radiated noise propagated outward by the equipment). The sound pressure level frequency response curve can be understood as a curve showing the change of sound pressure level at the target spatial field point with frequency, reflecting the distribution of radiated noise intensity of the enclosure at different frequencies, and is a direct basis for identifying frequencies exceeding noise limits and evaluating the noise reduction effect.

[0054] Specifically, based on the normal vibration velocity components of the casing surface. Using the RADSND acoustic module with the normal vibration velocity as the fluid-structure interaction boundary condition, the sound pressure at the target spatial point is obtained by solving the acoustic governing equations of the external sound field. and its effective value The acoustic behavior of the external sound field follows the Helmholtz equation. .in Sound pressure level (in Pa). For the Laplace operator, For wave number, ( (The speed of sound in air). This equation describes the sound pressure in the frequency domain. Spatial distribution patterns.

[0055] On the surface of the enclosure, the sound field and structural vibration satisfy the fluid-structure interaction boundary conditions, which establish a mathematical relationship between the normal vibration velocity of the structure and the normal sound pressure gradient of the sound field. ,in, The sound pressure is in the direction of the outer normal to the surface of the enclosure. Partial derivatives on, Let be the air density. This boundary condition indicates that the normal gradient of the sound pressure at the surface of the enclosure is composed of the surface normal vibration velocity component. With direct drive, the greater the vibration velocity, the greater the sound pressure gradient, and the stronger the sound energy radiated outward.

[0056] After obtaining the sound pressure at the target spatial field point, its effective value (i.e., the root mean square value of the sound pressure) is further calculated, and based on... Convert RMS values ​​to sound pressure levels ,in, Let be the sound pressure level at the angular frequency of the target spatial field point. This represents the effective sound pressure level at the target spatial field point at that frequency. The reference sound pressure level (i.e., the lowest sound pressure level that the human ear can perceive at a frequency of 1000Hz) is used. By traversing each frequency point within the set frequency band, the sound pressure level at each frequency is calculated, ultimately obtaining the sound pressure level frequency response curve for the target spatial field point. The sound pressure level frequency response curve reflects the noise level at the operator's ear position at each frequency.

[0057] S1033. Extract the peak value of the sound pressure level from the frequency response curve and determine the area of ​​concentrated vibration energy on the surface of the casing at the frequency corresponding to the peak value of the sound pressure level.

[0058] In this embodiment, the peak sound pressure level can be understood as the maximum point in the sound pressure level frequency response curve where the amplitude is significantly higher than that of the adjacent frequency band. The corresponding frequency is the main resonant frequency of the enclosure. At this frequency, the vibration amplitude of the enclosure surface is the largest, and the sound energy radiated outward is the strongest, which is the main cause of excessive noise.

[0059] Specifically, peak retrieval is performed on the sound pressure level frequency response curve to extract all local maxima points in the curve, and the highest sound pressure level peak and its corresponding frequency value are selected. Then, the normal vibration velocity distribution cloud map of the shell surface at that frequency is retrieved from the frequency response analysis results to determine the local area with the largest normal vibration velocity amplitude as the vibration energy concentration area.

[0060] As a fourth optional embodiment of this example, the shell panel portion corresponding to the vibration energy concentration area is taken as the target object. Under manufacturability constraints, the structural features of the target object are updated, an optimized shell geometric model is generated, and the shell geometric model is iteratively verified until the acoustic response meets the preset noise reduction requirements, including: S1041. The cover panel part corresponding to the area where the vibration energy is concentrated is taken as the target object.

[0061] In this embodiment, after determining the spatial location of the vibration energy concentration area, the panel part corresponding to the vibration energy concentration area in the numerical analysis model is extracted and set as the target object.

[0062] S1042. Using the set draft direction, minimum undulation width and maximum undulation height as constraints, the surface geometry of the target object is modified by morphology optimization algorithm and / or topology optimization algorithm to reduce the peak sound pressure level of the target spatial field point.

[0063] In this embodiment, setting the draft direction can be understood as a demolding direction set to ensure that the molded part can be smoothly ejected from the mold. This limits the modification of the surface geometry and avoids undercutting of the optimized uneven structure in the molding direction. The minimum undulation width can be understood as the minimum manufacturable size of the optimized calendered groove or reinforcing rib in the width direction. If it is lower than this size, the structure cannot be formed by stamping or injection molding. The maximum undulation height can be understood as the maximum manufacturable size of the optimized calendered groove or reinforcing rib in the height direction. If it is higher than this size, it may cause excessive stretching of the material and cracking, or lead to molding defects. The morphology optimization algorithm can be understood as an optimization algorithm that automatically perturbs the node coordinates along the surface normal of the casing, adaptively generating calendered grooves or corrugated reinforcing ribs on the surface of the target object. The topology optimization algorithm can be understood as an optimization algorithm that finds the optimal force transmission path by optimizing the distribution of material inside the target object while satisfying constraints.

[0064] Specifically, based on the identified target object, the draft direction, minimum undulation width, and maximum undulation height are set as manufacturing process constraints to ensure the manufacturability of the optimized results. Then, with the goal of reducing the peak value of the sound pressure level frequency response curve at the target spatial field point, morphology optimization and / or topology optimization algorithms are used to iteratively modify the surface geometry of the target object. The morphology optimization algorithm automatically perturbs the node coordinates along the surface normal of the target object, adaptively generating calendering grooves or corrugated reinforcing ribs on the shell surface to improve local stiffness. The topology optimization algorithm seeks the optimal balance between weight reduction and noise reduction by optimizing the material distribution inside the target object. If both algorithms are used simultaneously, the optimal material layout is first determined through topology optimization, and then morphology optimization is performed on the retained material area to generate reinforcing ribs. During the optimization process, the peak value of the sound pressure level at the target spatial field point is used as the objective function, and the global peak value of the sound pressure level at key field points within the target frequency band is minimized. Constraints limit the range of optimization parameters to avoid generating unmanufacturable geometric configurations.

[0065] S1043. Based on the modified surface geometry, generate an optimized housing geometry model. Re-verify the acoustic response of the optimized housing geometry model. If the reduction of the current sound pressure level peak compared to the initial peak does not reach the preset reduction threshold, iteratively perform optimization and verification until the reduction reaches the preset reduction threshold.

[0066] In this embodiment, acoustic response verification can be understood as re-executing steps S102 to S103 on the optimized enclosure geometry model to evaluate the actual noise reduction effect of the optimization scheme. The preset noise reduction threshold can be understood as a pre-set noise reduction requirement for determining whether the optimization meets the standard, typically determined based on factors such as product noise limits and human auditory discrimination capabilities. The initial peak value can be understood as the peak sound pressure level of the initial enclosure structure at the target spatial field point, extracted before geometric modification.

[0067] Specifically, based on the modified surface geometry, the shell geometry model is updated to generate an optimized shell geometry model. To evaluate the noise reduction effect of this optimization process, steps S102 to S103 need to be re-executed on the optimized shell geometry model, i.e., load mapping, frequency response analysis, and sound pressure level calculation are performed again to obtain the sound pressure level frequency response curve and its peak value at the optimized target spatial field point. The optimized sound pressure level peak value is compared with the initial peak value to calculate the reduction. If the current reduction does not reach the preset reduction threshold, the optimization is deemed unsatisfactory, and steps S1041 to S1042 are executed again based on the current optimization results, along with acoustic response verification. If the reduction reaches the preset reduction threshold, the optimization is deemed successful, the iteration is terminated, and the final shell geometry model is output.

[0068] For example, Figure 4 This is a comparison diagram of the surface velocity of a cover provided in an embodiment of the present invention; Figure 5 This is a comparison diagram of a sound pressure level cloud map provided in an embodiment of the present invention; Figure 6 This is a comparison diagram of a casing provided in an embodiment of the present invention; Figure 7 This is a comparison chart of sound pressure level frequency response curves provided in an embodiment of the present invention. The left side represents the curves before optimization, and the right side represents the curves after optimization. Figure 4-7As shown, taking the side cover of a certain type of overlock sewing machine as the object, under the set working condition of a spindle speed of 6000 RPM (corresponding to a fundamental frequency of 100 Hz), the transient time-domain excitation force at the coupling node between the internal mechanism and the cover is first extracted through rigid-flexible coupled multibody dynamics simulation. After frequency domain transformation, the frequency domain excitation load is obtained and applied as the excitation boundary condition to the finite element model of the cover. Based on the finite element model of the cover with the applied excitation boundary condition, frequency response analysis is performed to obtain the normal vibration velocity distribution on the surface of the cover, and the sound pressure level frequency response curve at the operator's ear position is further calculated. The sound pressure level frequency response curve of the initial structure shows a significant peak at 245 Hz, and the radiated sound pressure level at this frequency reaches 78 dB. The corresponding area on the surface of the cover exhibits a large-area thin-film vibration mode. The sound pressure level cloud map at this frequency shows a significant sound pressure distribution in the space outside the cover. For the above-mentioned area of ​​concentrated vibration energy, the surface geometry of the area is modified by a morphology optimization algorithm with the draft direction, minimum undulation width, and maximum undulation height as constraints, generating an optimized cover geometry model. The optimized enclosure geometry model was re-verified acoustically. The results showed that the peak sound pressure level shifted to 930 Hz, and the maximum radiated sound pressure level decreased to 65 dB, a reduction of approximately 13 dB compared to before optimization. This process verifies the feasibility and engineering applicability of the proposed method in identifying vibration hotspots, accurately locating noise sources, and effectively reducing noise.

[0069] This invention establishes a rigid-flexible coupled multibody dynamics model of the internal mechanism of a sewing device, defining the long, slender connecting rods and bent needle components as flexible bodies. It accurately captures the influence of elastic deformation of components and cutter impact loads on the excitation force under high-speed operation, extracting the transient time-domain excitation force containing periodic harmonic components and transient impact components. This solves the problem of excitation force distortion caused by neglecting flexible deformation and impact loads in traditional rigid body models, providing high-fidelity excitation input for subsequent acoustic analysis. Furthermore, the time-domain excitation force is converted into a frequency-domain excitation load through frequency-domain transformation and used as an excitation boundary condition spatially mapped to the corresponding nodes of the finite element model of the housing. This allows acoustic response analysis to be performed in the frequency domain, significantly reducing the computational cost of broadband acoustic response compared to traditional full-space boundary element or finite element methods. Rapid iterative optimization becomes possible; based on this, the sound pressure level at the target spatial field point is used as an evaluation index to replace the pure structural vibration index, which can truly reflect the noise perception of the operator's ear position, making the optimization target more physically meaningful; in the optimization stage, the present invention aims to minimize the global peak value of the sound pressure level frequency response curve within a set frequency band, and can dynamically track the resonance frequency drift during the iteration process, avoiding the noise reduction failure caused by frequency shift in fixed frequency optimization. At the same time, manufacturing process constraints such as draft direction, minimum undulation width, and maximum undulation height are introduced, and morphology optimization and / or topology optimization algorithms are used to automatically generate calendering grooves or corrugated reinforcing rib layouts, ensuring that the optimization results can be directly used for stamping or injection molding production; finally, a positive design closed loop of "excitation extraction → acoustic evaluation → structural optimization → verification feedback" is formed through iterative verification.

[0070] In one embodiment, Figure 8 This is a structural schematic diagram of a noise reduction design device for a housing provided in an embodiment of the present invention. Figure 8 As shown, the device includes: The excitation force extraction module 21 is used to establish a dynamic model of the internal mechanism of the sewing equipment and extract the transient time-domain excitation force at the coupling node between the internal mechanism and the cover under the set working conditions. Boundary condition application module 22 is used to apply the frequency domain excitation load corresponding to the transient time domain excitation force as the excitation boundary condition for forced vibration to the numerical analysis model of the cover. The region determination module 23 is used to determine the acoustic response radiated outward by the enclosure based on the numerical analysis model, extract the peak sound pressure level, and determine the vibration energy concentration area corresponding to the peak sound pressure level. The geometry optimization module 24 is used to take the cover panel part corresponding to the vibration energy concentration area as the target object, update the structural features of the target object under manufacturability constraints, generate an optimized cover geometry model, and iteratively verify the cover geometry model until the acoustic response meets the preset noise reduction requirements.

[0071] The noise reduction design device used in this technical solution achieves a closed loop of precise noise reduction, efficient design, and manufacturability optimization for the cover of the high-speed overlock sewing machine.

[0072] Optionally, the excitation force extraction module 21 is specifically used for: The connecting rods and bent needle components with a slenderness ratio greater than a preset threshold in the internal mechanism are identified as flexible bodies, and a rigid-flexible coupled multibody dynamics model of the internal mechanism is established. Using the spindle speed under the specified working conditions as the drive input, the rigid-flexible coupling multibody dynamics simulation is run. The three-dimensional transient time-domain excitation force at each bearing seat and fixed hinge point of the internal mechanism and the housing is extracted. The transient time-domain excitation force includes the periodic harmonic components generated by the operation of the internal mechanism and the blade impact load components.

[0073] Optionally, the boundary condition application module 22 is specifically used for: The transient time-domain excitation force is transformed in the frequency domain to obtain the frequency-domain excitation load; The frequency-domain excitation load is used as the excitation boundary condition for forced vibration and spatially mapped to the corresponding nodes of the numerical analysis model of the housing, wherein the numerical analysis model is a finite element model.

[0074] Optionally, the region determination module 23 is specifically used for: Based on the numerical analysis model with the applied excitation boundary conditions, frequency response analysis is performed to obtain the normal vibration velocity of the shell surface. Based on the normal vibration velocity, the sound pressure level radiated outward from the cover to the target space point is determined, and the sound pressure level frequency response curve is obtained. Extract the peak value of the sound pressure level from the sound pressure level frequency response curve, and determine the concentrated area of ​​vibration energy on the surface of the casing at the frequency corresponding to the peak value of the sound pressure level.

[0075] Optionally, the geometry optimization module 24 is specifically used for: The cover panel portion corresponding to the area where the vibration energy is concentrated is taken as the target object; With the draft direction, minimum undulation width, and maximum undulation height as constraints, the surface geometry of the target object is modified by using a topology optimization algorithm and / or a topology optimization algorithm to reduce the peak sound pressure level of the target spatial field point. Based on the modified surface geometry, an optimized housing geometry model is generated. The acoustic response of the optimized housing geometry model is then re-verified. If the reduction in the current sound pressure level peak value compared to the initial peak value does not reach the preset reduction threshold, optimization and verification are iteratively performed until the reduction reaches the preset reduction threshold.

[0076] Optionally, the target spatial field point includes the operator's ear position.

[0077] The noise reduction design device for the housing provided in the embodiments of the present invention can execute the noise reduction design method for the housing provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the method.

[0078] In one embodiment, Figure 9 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. For example... Figure 9 The diagram illustrates a schematic representation of an electronic device 10 that can be used to implement embodiments of the present invention. The electronic device 10 is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device 10 may also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices (e.g., helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein.

[0079] like Figure 9 As shown, the electronic device 10 includes at least one processor 11 and a memory, such as a read-only memory (ROM) 12 or a random access memory (RAM) 13, communicatively connected to the at least one processor 11. The memory stores computer programs executable by the at least one processor. The processor 11 can perform various appropriate actions and processes based on the computer program stored in the ROM 12 or loaded from storage unit 18 into the RAM 13. The RAM 13 can also store various programs and data required for the operation of the electronic device 10. The processor 11, ROM 12, and RAM 13 are interconnected via a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0080] Multiple components in electronic device 10 are connected to I / O interface 15, including: input unit 16, such as keyboard, mouse, etc.; output unit 17, such as various types of displays, speakers, etc.; storage unit 18, such as disk, optical disk, etc.; and communication unit 19, such as network card, modem, wireless transceiver, etc. Communication unit 19 allows electronic device 10 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0081] Processor 11 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 11 include, but are not limited to, central processing units, graphics processing units, various special-purpose artificial intelligence computing chips, various processors running machine learning model algorithms, digital signal processors, and any suitable processor, controller, microcontroller, etc. Processor 11 performs the various methods and processes described above, such as the casing noise reduction design method.

[0082] In some embodiments, the enclosure noise reduction design method can be implemented as a computer program tangibly contained in a computer-readable storage medium, such as storage unit 18. In some embodiments, part or all of the computer program can be loaded and / or installed on electronic device 10 via ROM 12 and / or communication unit 19. When the computer program is loaded into RAM 13 and executed by processor 11, one or more steps of the enclosure noise reduction design method described above can be performed. Alternatively, in other embodiments, processor 11 can be configured to perform the enclosure noise reduction design method by any other suitable means (e.g., by means of firmware).

[0083] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays, application-specific integrated circuits (ASICs), application-specific standard products (ASICs), systems-on-a-chip (SoCs), payload programmable logic devices, computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0084] Computer programs used to implement the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when executed by the processor, the computer programs cause the functions / operations specified in the flowcharts and / or block diagrams to be performed. The computer programs may be executed entirely on a machine, partially on a machine, or as a standalone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0085] In the context of this invention, a computer-readable storage medium can be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, apparatus, or device. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination thereof. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory, read-only memory, erasable programmable read-only memory, optical fibers, portable compact disk read-only memory, optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0086] To provide interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device (e.g., a cathode ray tube or liquid crystal display) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the electronic device. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0087] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as data servers), or computing systems that include middleware components (e.g., application servers), or computing systems that include frontend components (e.g., user computers with graphical user interfaces or web browsers through which users can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., communication networks). Examples of communication networks include local area networks (LANs), wide area networks (WANs), blockchain networks, and the Internet.

[0088] A computing system can include clients and servers. Clients and servers are generally geographically separated and typically interact via communication networks. The client-server relationship is created by computer programs running on the respective computers and having a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or cloud host, which is a host product within the cloud computing service system to address the shortcomings of traditional physical host and virtual machine services, such as high management difficulty and weak business scalability.

[0089] This invention also provides a computer program product, including a computer program that, when executed by a processor, can implement the casing noise reduction design method provided in any embodiment of this invention.

[0090] In implementing the computer program product, computer program code for performing the operations of this invention can be written in one or more programming languages ​​or a combination thereof. Programming languages ​​include object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages ​​such as C or similar languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including local area networks (LANs) or wide area networks (WANs), or it can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0091] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0092] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A noise reduction design method for a housing, characterized in that, include: A dynamic model of the internal mechanism of the sewing equipment is established, and the transient time-domain excitation force at the coupling node between the internal mechanism and the cover under the set working conditions is extracted. The frequency-domain excitation load corresponding to the transient time-domain excitation force is used as the excitation boundary condition for forced vibration and applied to the numerical analysis model of the housing. Based on the numerical analysis model, the acoustic response of the enclosure radiating outward is determined, the peak sound pressure level is extracted, and the vibration energy concentration area corresponding to the peak sound pressure level is determined. The shell panel corresponding to the area where the vibration energy is concentrated is taken as the target object. Under the manufacturability constraint, the structural features of the target object are updated to generate an optimized shell geometric model. The shell geometric model is then iteratively verified until the acoustic response meets the preset noise reduction requirements.

2. The method according to claim 1, characterized in that, The establishment of a dynamic model of the internal mechanism of the sewing equipment, and the extraction of the transient time-domain excitation force at the coupling node between the internal mechanism and the casing under a set working condition, includes: The connecting rods and bent needle components with a slenderness ratio greater than a preset threshold in the internal mechanism are identified as flexible bodies, and a rigid-flexible coupled multibody dynamics model of the internal mechanism is established. Using the spindle speed under the specified working conditions as the drive input, the rigid-flexible coupling multibody dynamics simulation is run. The three-dimensional transient time-domain excitation force at each bearing seat and fixed hinge point of the internal mechanism and the housing is extracted. The transient time-domain excitation force includes the periodic harmonic components generated by the operation of the internal mechanism and the blade impact load components.

3. The method according to claim 1, characterized in that, The numerical analysis model that applies the frequency-domain excitation load corresponding to the transient time-domain excitation force as the excitation boundary condition for forced vibration to the housing includes: The transient time-domain excitation force is transformed in the frequency domain to obtain the frequency-domain excitation load; The frequency-domain excitation load is used as the excitation boundary condition for forced vibration and spatially mapped to the corresponding nodes of the numerical analysis model of the housing, wherein the numerical analysis model is a finite element model.

4. The method according to claim 1, characterized in that, Based on the numerical analysis model, the acoustic response radiated outward from the enclosure is determined, the peak sound pressure level is extracted, and the vibration energy concentration region corresponding to the peak sound pressure level is determined, including: Based on the numerical analysis model with the applied excitation boundary conditions, frequency response analysis is performed to obtain the normal vibration velocity of the shell surface. Based on the normal vibration velocity, the sound pressure level radiated outward from the cover to the target space point is determined, and the sound pressure level frequency response curve is obtained. Extract the peak value of the sound pressure level from the sound pressure level frequency response curve, and determine the concentrated area of ​​vibration energy on the surface of the casing at the frequency corresponding to the peak value of the sound pressure level.

5. The method according to claim 1, characterized in that, The step of taking the enclosure panel portion corresponding to the concentrated vibration energy region as the target object, updating the structural features of the target object under manufacturability constraints, generating an optimized enclosure geometric model, and iteratively verifying the enclosure geometric model until the acoustic response meets the preset noise reduction requirements includes: The cover panel portion corresponding to the area where the vibration energy is concentrated is taken as the target object; With the draft direction, minimum undulation width, and maximum undulation height as constraints, the surface geometry of the target object is modified by using a topology optimization algorithm and / or a topology optimization algorithm to reduce the peak sound pressure level of the target spatial field point. Based on the modified surface geometry, an optimized housing geometry model is generated. The acoustic response of the optimized housing geometry model is then re-verified. If the reduction in the current sound pressure level peak value compared to the initial peak value does not reach the preset reduction threshold, optimization and verification are iteratively performed until the reduction reaches the preset reduction threshold.

6. The method according to claim 4, characterized in that, The target spatial field point includes the operator's ear position.

7. A noise reduction design device for a housing, characterized in that, include: The excitation force extraction module is used to establish a dynamic model of the internal mechanism of the sewing equipment and extract the transient time-domain excitation force at the coupling node between the internal mechanism and the cover under the set working conditions. The boundary condition application module is used to apply the frequency domain excitation load corresponding to the transient time domain excitation force as the excitation boundary condition for forced vibration to the numerical analysis model of the cover. The region determination module is used to determine the acoustic response radiated outward by the enclosure based on the numerical analysis model, extract the peak sound pressure level, and determine the vibration energy concentration area corresponding to the peak sound pressure level. The geometry optimization module is used to take the shell panel part corresponding to the vibration energy concentration area as the target object, update the structural features of the target object under manufacturability constraints, generate an optimized shell geometry model, and iteratively verify the shell geometry model until the acoustic response meets the preset noise reduction requirements.

8. An electronic device, characterized in that, include: At least one processor; as well as A memory communicatively connected to the at least one processor; wherein, The memory stores a computer program that can be executed by the at least one processor, the computer program being executed by the at least one processor to enable the at least one processor to perform a casing noise reduction design method according to any one of claims 1-6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions that cause a processor to execute and implement the casing noise reduction design method according to any one of claims 1-6.

10. A computer program product, characterized in that, The computer program product includes a computer program that, when executed by a processor, implements a casing noise reduction design method according to any one of claims 1-6.

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