Digital R & D Method and System for Lightweighting of Power Tools Based on Numerical Calculation

Abstract

This application is a numerical-computation-based digital R & D method and system for the lightweighting of power tools, belonging to the field of power tool optimization. Aiming at the obvious limitations in the R & D of existing table saw power tools, a numerical-computation-based digital R & D method for the lightweighting of power tools is provided: According to the division of functional roles and connection relationships, table saw power tools are disassembled into different functional components; Standardized functional analysis modules for each functional component are constructed based on the finite element analysis method; A digital 3D model of the functional components of the table saw power tool is obtained, and the surface feature information and load parameters obtained by the interaction of the corresponding functional components are set. By outputting the stress, strain, and deformation data of the corresponding functional components and converting them into the corresponding cloud map results. This application modularizes each functional component of the power tool, can adapt to and verify different application scenarios and customer requirements, reduce the difficulty of pre-processing settings for finite element analysis, and can also reduce costs and technical thresholds and shorten the R & D cycle.

Description

Technical Field

[0001] The present invention belongs to the field of electric tool optimization, and particularly relates to a lightweight digital R & D method and system for electric tools based on numerical calculation. Background Art

[0002] With the continuous progress of technology and the increasing diversification of market demands, the R & D of electric tools such as table saws is gradually developing towards modularization. This trend not only improves the flexibility and adaptability of products, but also greatly shortens the product R & D cycle, meeting the market's requirements for rapid iteration and customization.

[0003] However, the challenges brought by modular design are also obvious. Traditional R & D processes and tools can no longer meet the growing digital R & D needs. Especially in the market environment where electric tool products are rapidly iterated and gradually customized, small and medium-sized enterprises are under great pressure. They need a more efficient and flexible R & D system to cope with the large-scale annual updates and optimization requirements.

[0004] In the current R & D field of table saw electric tools, traditional technical solutions mainly rely on the trial-and-error method of mechanical engineers. The core of this method lies in gradually optimizing the design through continuous experiments and errors, but this process has significant defects. First of all, the trial-and-error method requires repeated product proofing designs. Each design iteration requires the actual manufacture of prototypes, which not only consumes time, but also consumes materials and human resources, and prolongs the R & D cycle.

[0005] Simulation engineers use simulation means for digital R & D. Although this method can theoretically reduce the need for physical prototypes, it also has its defects. The simulation process needs to rely on a large amount of human experience, which means that the accuracy of the results depends to a large extent on the professional level and experience of the operator. In addition, the hardware cost of local simulation calculation is high and the calculation time is long, which is a heavy burden for small and medium-sized enterprises. The technical difficulty is high and the knowledge level of users is required to be relatively high, so the application scope and popularization of simulation technology are restricted. The license fee of simulation software is expensive, which is also not conducive to the popularization of digital R & D, especially in small and medium-sized enterprises with limited resources.

[0006] In summary, the existing technical solutions have obvious limitations in the R & D of table saw electric tools. The cost and time consumption of the trial-and-error method, as well as the high threshold and cost of simulation technology, have restricted the R & D efficiency and innovation speed. These problems highlight the need for a lightweight R & D method and system that can reduce costs, shorten the R & D cycle, and lower the technical threshold to adapt to the rapidly changing market environment and the actual needs of small and medium-sized enterprises. Summary of the Invention

[0007] In view of the problems of the prior art, the present invention provides a lightweight digital R & D method and system for power tools based on numerical calculation, aiming to provide a cost-effective, easy-to-implement and operate digital solution. This application will integrate the concept of modular design and achieve a rapid conversion from conceptual design to product prototype through digital tools and platforms.

[0008] This application provides a lightweight digital R & D method for power tools based on numerical calculation, including:

[0009] S1, according to the division of functional roles and connection relationships, disassemble power tools of the table saw type into different functional components;

[0010] S2, construct standardized functional analysis modules for each functional component based on the finite element analysis method:

[0011] Construct standardized functional modules for each functional component respectively;

[0012] Assign materials to each functional module according to the physical material properties of each functional component;

[0013] Form boundary constraints for each functional model according to the connection relationships of each functional component;

[0014] Preset the application direction and magnitude of the load according to the loading conditions of each functional module, and preset the mapping relationship between the interactive feature surface and the load-bearing surface;

[0015] Take the stress, strain, deformation data and corresponding nephogram results under different working conditions as the output results of each functional module, and thus form standardized functional analysis modules for each functional component;

[0016] Among them, the boundary constraints include the constraints of the boundary surface, degrees of freedom, load-bearing surface and loading direction of each functional model. The input quantities of the model include quantitative and variable quantities. The boundary constraint conditions and load direction setting conditions of the functional module are quantitative, and the material assignment of the functional module, the boundary constraint mapping feature surface, the load magnitude received by the functional module and the load-bearing surface feature are variable quantities;

[0017] S3, obtain the digital three-dimensional model of the functional components of the table saw type power tool, set the surface feature information and load parameters obtained by the corresponding functional component interaction, so that the standardized functional analysis module of the corresponding functional component outputs the stress, strain and deformation data of the corresponding functional component, and converts them into corresponding nephogram results, realizing the strength analysis of the obtained functional components.

[0018] The interactive feature surface and the load-bearing surface are mutually mapped. The mapping relationship between the two is mainly reflected in the specific matching in terms of geometric shape and the consistency of boundary constraint relationships. The purpose of such a setting is to facilitate the subsequent digital three-dimensional model of the functional components of the table saw type power tool to quickly form a link with the standardized functional analysis modules of each constructed functional component, facilitating subsequent processing.

[0019] The constructed standardized functional model is a general model. Users can select and set the surface feature information, so that the connection relationship of the obtained digital geometric model is fixed. Furthermore, the stress, strain, and deformation under the set load can be used to confirm the analysis results of the digital three-dimensional model of the functional components of the table saw type power tool input.

[0020] The prior art usually constructs a model of the entire power tool, rather than separately modeling each functional component of the power tool. This results in the need for overall simulation when changing some working conditions, with a long simulation time and low efficiency. The inventive point of this application lies in modularizing each functional component of the table saw type power tool, facilitating the combination and reconfiguration of different components to adapt to and verify different application scenarios and customer requirements. In addition, it can also facilitate data management and sharing.

[0021] In this application, each functional component of the power tool is disassembled, and the connection relationship between each functional component forms the constraints of the functional model, enabling separate modeling of each functional component. When one or several functional modules are separately changed, the working states under different working conditions can be obtained, reducing the difficulty of preprocessing settings for finite element analysis. This method can also reduce costs, shorten the R & D cycle, and lower the technical threshold to meet the actual needs of the rapidly changing market environment and small and medium-sized enterprises.

[0022] Furthermore, the table saw type power tool divides five key functional components for analysis, namely the die-casting turntable, the swing arm, the saw blade, the connecting head, and the die-casting base, according to the functional role and connection relationship. Among them, both ends of the die-casting base are respectively connected to the tabletop and the die-casting turntable, both ends of the die-casting turntable are respectively connected to the die-casting base and the swing arm, both ends of the swing arm are respectively connected to the die-casting turntable and the slide bar, both ends of the connecting head are respectively connected to the slide bar and the saw head, and the saw blade is connected to the saw head.

[0023] Furthermore, based on the finite element analysis method, a standardized functional analysis module for the die-casting turntable is constructed:

[0024] Construct a standardized functional module for the die-casting turntable;

[0025] Assign materials to the functional module of the die-casting turntable according to the physical material properties of the die-casting turntable;

[0026] Form the boundary constraints of the functional modules of the die-casting turntable according to the connection relationship: Preset the inner wall surface of the bolt holes at the bottom of the die-casting turntable as the constraint surface, and set the rotational and translational degrees of freedom of the constraint surface. Set the inner wall surface of the central axis at the connection between the turntable and the rocker arm as the load-bearing surface;

[0027] Preset the application direction and magnitude of the load according to the load-bearing conditions of the functional modules of the die-casting turntable, and preset the mapping relationship between the interactive feature surface and the load-bearing surface;

[0028] Through the numerical calculation method, output the stress, strain, and deformation data of the die-casting turntable under different working conditions, and then form a standardized functional analysis module for the die-casting turntable.

[0029] Furthermore, construct a standardized functional analysis model for the rocker arm based on the finite element analysis method:

[0030] Construct a standardized functional module for the rocker arm;

[0031] Assign materials to the functional modules of the rocker arm according to the physical material properties of the rocker arm;

[0032] Form the boundary constraints of the functional modules of the rocker arm according to the connection relationship: Preset the inner wall surface where the rocker arm is connected to the central axis of the turntable as the constraint surface, and set the rotational and translational degrees of freedom of the constraint surface. Set the inner wall surface of the hole at the connection between the rocker arm and the slide bar as the load-bearing surface;

[0033] Preset the application direction and magnitude of the load according to the load-bearing conditions of the functional modules of the rocker arm, and preset the mapping relationship between the interactive feature surface and the load-bearing surface;

[0034] Adopt the non-linear contact algorithm to output the stress, strain, and deformation data of the rocker arm under different working conditions, and then form a standardized functional analysis module for the die-casting turntable.

[0035] Furthermore, construct a standardized functional analysis module for the saw blade based on the finite element analysis method:

[0036] Construct a standardized functional module for the saw blade;

[0037] Assign materials to the functional modules of the saw blade according to the physical material properties of the saw blade;

[0038] Form the boundary constraints of the functional modules of the saw blade according to the connection relationship:

[0039] In the axial loading working condition mode, set the outer periphery edge of the saw blade as the constraint surface, limit all degrees of freedom of the constraint surface according to the numerical calculation method, set the surface of the saw blade as the load-bearing surface, and set the axial direction of the saw blade as the force application direction;

[0040] Under the saw blade loading condition mode, the inner wall surface of the central hole of the saw blade is preset as the constraint surface, the rotational and translational degrees of freedom of the constraint surface are set, and the saw tooth surface is set as the load bearing surface;

[0041] Preset the application direction and magnitude of the load according to the loading condition of the functional module of the saw blade, and preset the mapping relationship between the interactive feature surface and the load bearing surface;

[0042] Adopt the numerical calculation method to output the stress, strain, and deformation data of the saw blade under different working conditions, and then form a standardized functional analysis module for the saw blade.

[0043] Furthermore, based on the finite element analysis method, construct a standardized functional analysis model for the connector:

[0044] Construct a standardized functional module for the connector;

[0045] Assign materials to the functional module of the connector according to the physical material properties of the connector;

[0046] Form the boundary constraints of the functional module of the connector according to the connection relationship:

[0047] Preset the inner wall surface of the hole where the connector is connected to the sliding rod as the constraint surface, set the rotational and translational degrees of freedom of the constraint surface, and set the inner wall surface of the hole at the connection between the rocker arm and the sliding rod as the load bearing surface;

[0048] Preset the application direction and magnitude of the load according to the loading condition of the functional module of the connector, and preset the mapping relationship between the interactive feature surface and the load bearing surface of the connector;

[0049] Adopt the numerical calculation method to output the stress, strain, and deformation data of the connector under different working conditions, and then form a standardized functional analysis module for the connector.

[0050] Furthermore, based on the finite element analysis method, construct a standardized functional analysis module for the die-casting base:

[0051] Construct a standardized functional module for the die-casting base;

[0052] Assign materials to the functional module of the die-casting base according to the physical material properties of the die-casting base;

[0053] Form the boundary constraints of the die-casting base according to the connection relationship:

[0054] Preset the contact surface of the support feet of the die-casting base as the constraint surface, restrict all degrees of freedom of the constraint surface as a fixed support, and set the central surface of the die-casting base as the load bearing surface;

[0055] Preset the application direction and magnitude of the load according to the loading condition of the functional module of the die-casting base, and preset the mapping relationship between the interactive features of the die-casting turntable and the load bearing surface;

[0056] Using the numerical calculation method, the stress, strain, and deformation data of the die-casting turntable under different working conditions are output, and then a standardized functional analysis module of the die-casting base is formed.

[0057] Furthermore, based on the obtained digital three-dimensional models of the functional components of the table saw type power tools and the output stress, strain, and deformation data of the corresponding functional components, and rendering in the Paraview open source environment, the stress and deformation distribution maps and digital verification reports of the corresponding functional components are obtained. The stress, strain, and deformation data, and the corresponding cloud map results can be transformed into a stress distribution map and an analysis report, which can help engineers obtain intuitive data.

[0058] A power tool lightweight system based on numerical calculation, comprising:

[0059] A partitioning module, which partitions according to the functional roles and connection relationships, and deconstructs the table saw type power tools into different functional components;

[0060] A construction module, which constructs a standardized functional analysis module for each functional component based on the finite element analysis method:

[0061] Construct standardized functional modules for each functional component respectively;

[0062] Perform material assignment for each functional module according to the physical material properties of each functional component;

[0063] Form boundary constraints for each functional model according to the connection relationships of each functional component;

[0064] Preset the application direction and magnitude of the load according to the loading conditions of each functional module, and preset the mapping relationship between the interaction characteristics and the load bearing surface;

[0065] Take the stress, strain, and deformation data and the corresponding cloud map results under different working conditions as the output results of each functional module;

[0066] A calculation module, which obtains the digital three-dimensional model of the functional components of the table saw type power tools, sets the surface feature information and load parameters obtained by the corresponding functional component interaction, so that the standardized functional analysis model of the corresponding functional component outputs the stress, strain, and deformation data of the corresponding functional component, and transforms them into the corresponding cloud map results.

[0067] A power tool lightweight system based on numerical calculation, which includes:

[0068] One or more processors;

[0069] A storage device for storing one or more programs;

[0070] When the one or more programs are executed by the one or more processors, the one or more processors implement the above-mentioned lightweight digital R & D method for power tools based on numerical calculation.

[0071] Beneficial effects: The present application is a lightweight digital R & D method and system for power tools based on numerical calculation. The various functional components of the power tool are modularized, which is convenient for combining and reconfiguring different components to adapt to and verify different application scenarios and customer requirements. The connection relationships between the various functional components form the constraints of the functional model, enabling individual modeling of each functional component and reducing the difficulty of pre-processing settings for finite element analysis. This method can also reduce costs, shorten the R & D cycle, and lower the technical threshold to meet the actual needs of the rapidly changing market environment and small and medium-sized enterprises. Description of the drawings

[0072] Figure 1 It is a schematic flow chart of Embodiment 1;

[0073] Figure 2 It is a schematic diagram of the result of Application Example 1;

[0074] Figure 3 It is a schematic diagram of the result of Application Example 2. Detailed implementation manners

[0075] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0076] In the specific solution of the present application, a modular lightweight R & D system for table saw power tools is proposed, aiming to assist engineers in completing the R & D tasks of most components through a standardized solution. The core of this system lies in its five major modules, and each module conducts strength analysis on the key components of the power tool to ensure the reliability and optimization of the design.

[0077] Embodiment 1

[0078] This embodiment provides a lightweight digital R & D method for power tools based on numerical calculation. The flow chart is as Figure 1 shown, and the specific process includes:

[0079] S1. Decompose the bench saw type power tool into different functional components according to the functional roles and connection relationships. The bench saw type power tool is decomposed into five key functional components for analysis, namely the die-casting turntable, the swing arm, the saw blade, the connector, and the die-casting base according to the functional roles and connection relationships. The two ends of the die-casting base are respectively connected to the tabletop and the die-casting turntable. The two ends of the die-casting turntable are respectively connected to the die-casting base and the swing arm. The two ends of the swing arm are respectively connected to the die-casting turntable and the slide bar. The two ends of the connector are respectively connected to the slide bar and the saw head. The saw blade is connected to the saw head. Each module aims to provide a standardized solution to assist engineers in efficiently completing the R & D tasks.

[0080] S2. Construct a standardized functional analysis module for each functional component based on the finite element analysis method:

[0081] In this embodiment, the boundary constraints include the constraints on the boundary surfaces, degrees of freedom, force-bearing surfaces, and force directions of each functional model. The input quantities of the model include quantitative and variable quantities. The boundary constraint conditions and load direction setting conditions of the functional module are quantitative, and the material assignment of the functional module, the boundary constraint mapping feature surface, the magnitude of the load received by the functional module, and the force-bearing surface characteristics of the load are variable quantities.

[0082] S2.1. Construct a standardized functional analysis module for the die-casting turntable based on the finite element analysis method:

[0083] Construct a standardized functional module for the die-casting turntable;

[0084] Perform material assignment for the functional module of the die-casting turntable according to the physical material properties of the die-casting turntable;

[0085] Form the boundary constraints of the functional module of the die-casting turntable according to the connection relationship: Preset the inner wall surface of the bolt hole at the bottom of the die-casting turntable as the constraint surface, and set the rotational degree of freedom and translational degree of freedom of the constraint surface. Set the inner wall surface of the central axis at the connection between the turntable and the swing arm as the force-bearing surface of the load;

[0086] The process of setting the rotational degree of freedom and translational degree of freedom includes:

[0087] Set the z-axis rotational degree of freedom (i.e., the rotation of the turntable around the axis of the bolt hole) according to the rotation matrix; where the expression of the rotation matrix is:

[0088]

[0089] Among them, is the angle of rotation of the turntable around the Z axis, which controls the rotation of the turntable. The rotation matrix is applied to each node coordinate on the surface of the turntable, and the transformed coordinates are obtained after transformation to ensure that the rotation state of the turntable can be accurately simulated;

[0090] In addition to releasing the rotational freedom of the Z-axis, the module also restricts the other five degrees of freedom of the inner wall surface of the bolt hole, including the translational degrees of freedom of the X-axis, Y-axis, and Z-axis, as well as the rotational degrees of freedom of the X-axis and Y-axis, ensuring the accuracy of the simulation. The translational degrees of freedom of the x-axis and y-axis and the rotational degrees of freedom of the x-axis and y-axis are set according to the constraint equations, and the constraint equations are as follows:

[0091]

[0092] Among them, , , represent the translational degrees of freedom of the X, Y, and Z axes, , represent the rotational degrees of freedom of the X and Y axes.

[0093] To more realistically reflect the loading conditions of the overall structure under actual working conditions, the inner wall surface of the central axis where the turntable is connected to the rocker arm is selected as the load-bearing surface, and the loading direction is controlled to be the standard gravity direction.

[0094] According to the loading conditions of the functional modules of the die-casting turntable, preset the application direction and magnitude of the load, and preset the mapping relationship between the interactive feature surface and the load-bearing surface of the die-casting turntable;

[0095] The distribution of the load in the Z-axis direction can be expressed as:

[0096]

[0097] Among them, ρ is the material density, g is the acceleration due to gravity, and A(x,y) is the area distribution function of the load-bearing surface in the x,y plane. Through the numerical integration method, the load value at each point on the load-bearing surface can be obtained and applied to the finite element model of the turntable surface for stress and deformation analysis.

[0098] The formula based on the geometric shape of the turntable and the load distribution is:

[0099]

[0100] Among them, is the vector from the force application point to the center of the turntable, is the force acting on this point, dA is the infinitesimal area element on the load-bearing surface, and the moment M represents the loading condition of the turntable. In actual calculations, the load distribution will be discretized according to the shape characteristics and working conditions of the turntable, and the distribution diagrams of the moment and stress are calculated by the numerical calculation method to accurately simulate the loading state of the turntable in actual work.

[0101] The force application direction is set to the standard gravity direction. Through the numerical integration method, the load value at each point on the force-bearing surface is obtained. The magnitude and direction of the load are calculated through the moment formula and the force distribution function, and then the stress and deformation data of the die-casting turntable are obtained.

[0102] Through the numerical calculation method, the stress, strain values and stress distribution diagrams of the die-casting turntable under different working conditions are output, and then a standardized functional analysis module of the die-casting turntable is formed.

[0103] S2.2, constructing a standardized functional model of the rocker arm based on the finite element analysis method:

[0104] Construct a standardized functional analysis module for the rocker arm;

[0105] Assign materials to the functional modules of the rocker arm according to the physical material properties of the rocker arm;

[0106] Form boundary constraints for each functional model according to the connection relationship: preset the inner wall surface connecting the rocker arm to the turntable central axis as the constraint surface, and set the rotational and translational degrees of freedom of the constraint surface. Set the inner wall surface of the hole at the connection between the rocker arm and the slide bar as the load-bearing surface; the inner wall surface connected to the turntable central axis (the central axis is set as the Z-axis rotational degree of freedom of this component) is set as the constraint application surface, restricting five degrees of freedom (X-axis translational degree of freedom, Y-axis translational degree of freedom, Z-axis translational degree of freedom, X-axis rotational degree of freedom, and Y-axis rotational degree of freedom) to ensure the stability of the rocker arm. This process can be achieved through the following constraint equations:

[0107]

[0108] Among them, , , represent the translational degrees of freedom of the X, Y, and Z axes, , represent the rotational degrees of freedom of the X and Y axes.

[0109] Preset the application direction and magnitude of the load according to the load-bearing conditions of the functional modules of the rocker arm, and preset the mapping relationship between the interactive feature surface and the load-bearing surface;

[0110] The slide bar is connected to the rocker arm. The length of the slide bar is relatively important. The coupling point simulates the role of the slide bar. Apply force to the coupling point, set the coupling point to transfer force, and set the force-bearing coupling point (along the direction of the slide bar, the distance is the input slide bar length value) through the slide bar length provided by the engineer. Transfer the downward pressure applied to the coupling point to the load-bearing surface to simulate the force-bearing situation in actual work. Specifically, the calculation of the force on the coupling point depends on the following formula:

[0111]

[0112] Among them, is the force at the coupling point, k is the coupling coefficient, which is determined by factors such as the coupling system movement speed, and is fitted through experimental data or material parameters (specifically analyzed in the finite element analysis model and obtained through calculation). This coefficient ensures that the input pressure can be accurately transmitted to the coupling point and further act on the force-bearing surface.

[0113] The dynamic responses of the contact surface and the contact point are processed using a non-linear contact algorithm. The calculation of the contact force depends on the contact stiffness matrix, and the deformation of the contact point is described by the following formula:

[0114]

[0115] Among them, is the deformation of the contact point, is the force applied to the contact point, and K is the contact stiffness matrix. This algorithm updates the position and state of the contact point through iteration to ensure that the mechanical transmission between the force-bearing surface and the coupling point meets the actual working conditions during the simulation. This digital process enhances the accuracy of the rocker arm strength analysis and provides strong support for the optimization design.

[0116] Using the above non-linear contact algorithm, the stress, strain, and deformation data of the rocker arm under different working conditions are obtained.

[0117] S2.3, constructing a standardized functional analysis module for the saw blade based on the finite element analysis method:

[0118] Construct a standardized functional analysis module for the saw blade;

[0119] Assign materials to the functional modules of the saw blade according to the physical material properties of the saw blade;

[0120] Form the boundary constraints of the functional modules of the saw blade according to the connection relationship:

[0121] Under the axial loading condition mode, set the outer edge of the saw blade as the constrained surface, restrict all degrees of freedom of the constrained surface according to the numerical calculation method, set the saw blade surface as the load-bearing surface, and set the saw blade axis direction as the force direction; under the axial loading condition mode, the load direction is usually determined by the saw blade axis direction, and the direction vector represents the load direction. The numerical calculation of the load is achieved through the following formula:

[0122]

[0123] Among them, P is the magnitude of the applied load, is the load direction vector, and is defined through the geometric relationship between the axis and the load application surface.

[0124] In the sawtooth loading condition mode, the inner wall surface of the central hole of the saw blade is preset as the constraint surface, the rotational and translational degrees of freedom of the constraint surface are set, the sawtooth surface is set as the load-bearing surface, and the force application direction is set;

[0125] In the sawtooth loading condition mode, the load direction is defaulted to the combined normal vector of the selected surface or surface combination on the side of the saw blade. The numerical calculation of the load is achieved through the combination of the surface normal vector and the load magnitude P:

[0126]

[0127] Among them, is the normal vector of the selected surface or surface combination, and P is the load magnitude. The numerical model of load transfer is dynamically updated based on the contact stiffness matrix, and the force distribution when the load acts on the sawtooth surface is iteratively calculated to ensure the accuracy of the simulation. This data-based processing method realizes the reasonable distribution of the load through numerical solution, thereby effectively simulating the stress condition of the saw blade in actual work.

[0128] When performing sawtooth loading, the constraint is fixed on the inner wall surface of the central hole of the saw blade, the load is applied on the sawtooth surface, and the load direction is defaulted to the combined normal vector of the selected surface or surface combination on the side of the saw blade; the magnitude of the load is calculated; the numerical model of load transfer is dynamically updated based on the contact stiffness matrix, and the force distribution when the load acts on the sawtooth surface is iteratively calculated; this data-based processing method realizes the reasonable distribution of the load through numerical solution, thereby effectively simulating the stress condition of the saw blade in actual work.

[0129] Preset the application direction and magnitude of the load according to the load conditions of the functional modules of the saw blade, and preset the mapping relationship between the interactive feature surface and the load-bearing surface;

[0130] Adopt the above numerical calculation method to output the stress, strain, and deformation data of the saw blade under different working conditions.

[0131] S2.4, construct a functional analysis model for the standardization of the connector based on the finite element analysis method:

[0132] Construct a standardized functional module of the connector;

[0133] Assign materials to the functional modules of the connector according to the physical material properties of the connector;

[0134] Form the boundary constraints of the functional modules of the connector according to the connection relationship:

[0135] Preset the inner wall surface of the hole connecting the connector and the sliding rod as the constraint surface, set the rotational and translational degrees of freedom of the constraint surface, and set the inner wall surface of the hole at the connection of the rocker arm and the sliding rod as the load-bearing surface;

[0136] The constrained part in this section is at the inner wall position of the hole connected to the sliding rod. Since the connection between the connecting head and the saw head housing is a rotating pair connected by bolts (assuming the central axis is the Z-axis), during the setting of this part, five degrees of freedom of the inner wall surface of the connecting bolt shaft between the connecting head and the saw head are constrained (translation degrees of freedom in the X-axis, Y-axis, and Z-axis, rotation degrees of freedom in the X-axis, and Y-axis), and the rotation degree of freedom in the Z-axis is released. This process can be achieved through the following constraint equations:

[0137]

[0138] Among them, , , represent the translation degrees of freedom of the X, Y, and Z axes, , represent the rotation degrees of freedom of the X and Y axes. The load is applied at the corresponding saw head handle, and the load direction is determined as the gravity direction.

[0139] According to the load-bearing conditions of the functional modules of the connecting head, preset the application direction and magnitude of the load, and preset the mapping relationship between the interactive characteristic surface and the load-bearing surface of the connecting head;

[0140] Adopt the numerical calculation method to output the stress, strain, and deformation data of the connecting head under different working conditions, and then form a standardized functional analysis module for the connecting head.

[0141] S2.5. Based on the finite element analysis method, construct a standardized functional analysis module for the die-casting base:

[0142] Construct a standardized functional module for the die-casting base;

[0143] Assign materials to the functional modules of the die-casting base according to the physical material properties of the die-casting base;

[0144] Form the boundary constraints of the die-casting base according to the connection relationship:

[0145] Preset the contact surface of the support feet of the die-casting base as the constrained surface, restrict all degrees of freedom of the constrained surface, and use it as a fixed support. Set the central surface of the die-casting base as the load-bearing surface;

[0146] According to the load-bearing conditions of the functional modules of the die-casting base, preset the application direction and magnitude of the load, and preset the mapping relationship between the interactive characteristic surface and the load-bearing surface of the die-casting turntable;

[0147] Adopt the numerical calculation method to output the stress, strain, and deformation data of the die-casting turntable under different working conditions.

[0148] The static pressure simulation is mainly carried out on the die-cast base. The support feet of the die-cast base (set by engineers according to specific working conditions) are used as fixed constraints, and a load is applied to the center surface of the die-cast base, with the load direction being the gravity direction.

[0149] S3. Obtain the digital 3D model of the functional components of the table saw type power tool, set the surface feature information and load parameters obtained by the interaction of the corresponding functional components, so that the standardized functional analysis model of the corresponding functional components outputs the stress, strain and deformation data of the corresponding functional components, and converts them into the corresponding cloud map results.

[0150] The analysis results are rendered and displayed in the Paraview open source environment by precisely converting the post-processing result file into a widely supported VTK visualization file format, providing the stress and deformation distribution maps of the die-cast turntable of the power tool under working conditions, and issuing the corresponding digital verification report to provide intuitive analysis results for engineers.

[0151] When constructing each standardized functional model based on the finite element analysis method, the model is corrected by measured data to ensure the accuracy of the model. The specific method is to compare the test data with the data output by the constructed model. If it is within the threshold range, the model iteration is stopped. After the test data, the collected data is processed. When collecting, the eddy current is used to collect the real-time electrical signal, and the fast Fourier transform (FFT) algorithm is used to obtain the frequency and its distribution of the electrical signal (sinusoidal harmonics of different frequencies); the formula for Fourier transform is:

[0152]

[0153] where, v(t) is the time-domain signal, V(ω) is its Fourier transform, j is the imaginary unit, and ω is the angular frequency;

[0154] Based on the frequency and its distribution of the electrical signal (sinusoidal harmonics of different frequencies), the phase is extracted according to the phase demodulation method; the frequency components and phase information of the signal can be obtained through Fourier transform, and the phase demodulation technology depends on the analysis of these phase information. The formula for phase extraction can be expressed as:

[0155]

[0156] where, is the phase angle at the frequency component and represents the phase of the complex number.

[0157] According to the phase change at different time points, calculate the extreme value and difference of the displacement. The calculation formula for the displacement change is:

[0158]

[0159] Among them, and are the phases at times and respectively, and is the frequency component related to the displacement change. Based on this, the extreme value and difference of the displacement are obtained.

[0160] For the constructed finite element model, an unstructured grid generation algorithm is adopted, including the Delaunay method and the Advancing-Front method (wavefront method), to ensure that the grid attributes can be dynamically adjusted during the generation process, with good controllability, and the finally generated grid quality is also good.

[0161] Among them, the Delaunay triangulation used is a triangulation method based on the Delaunay condition, that is, for any triangle in the triangulation, no other points should be contained within its circumcircle. This method can ensure that the generated triangles are as close to equilateral triangles as possible, thereby improving the grid quality.

[0162] Algorithm steps:

[0163] 1. Start with a large triangle containing all points.

[0164] 2. Insert points into the triangulation one by one. Each time a point is inserted, it is checked whether the point is within the circumcircle of the existing triangles.

[0165] 3. If the point is within the circumcircle of a certain triangle, then split the triangle into three new triangles so that the new point becomes the vertex of one of the triangles.

[0166] 4. Repeat the above steps until all points are inserted.

[0167] The Advancing-Front method is a grid generation method that advances layer by layer. It starts from an initial boundary and gradually expands towards the interior to form new grid cells. Algorithm steps:

[0168] 1. Define an initial boundary, usually the geometric boundary of the problem.

[0169] 2. Select a point on the boundary as the vertex of the new triangle.

[0170] 3. Select an edge on the boundary and connect it to the new vertex to form a new triangle.

[0171] 4. Update the boundary by adding the opposite side of the newly formed triangle to the boundary.

[0172] 5. Repeat the above steps until all regions are meshed.

[0173] The connection between the turntable and the rocker arm is realized through a central axis bolt. Set this connection state as a fixed connection between geometric bodies, with the turntable as the fixed target and the rocker arm as the contact target, and automatically generate a coordinate system based on the central axis of the two. This involves determining the position and direction of the connection point, and the following formula can be used to define the origin and direction of the coordinate system:

[0174]

[0175]

[0176] Among them, is the position vector of the origin of the coordinate system, is the unit vector along the central axis direction; is the position vector of the center of gravity of the turntable geometric body, is the position vector of the center of gravity of the rocker arm geometric body.

[0177] Embodiment 2

[0178] A lightweight system for power tools based on numerical calculation, comprising:

[0179] A division module, which divides the power tools of the table saw type into different functional components according to the functional roles and connection relationships;

[0180] A construction module, which constructs a standardized functional analysis module for each functional component based on the finite element analysis method:

[0181] Construct the functional modules of each functional component respectively;

[0182] Perform material assignment for each functional module according to the physical material properties of each functional component;

[0183] Form the boundary constraints of each functional model according to the connection relationships of each functional component;

[0184] Preset the application direction and magnitude of the load according to the loading conditions of each functional module, and preset the mapping relationship between the interactive feature surface and the loaded surface;

[0185] Take the stress, strain, deformation data and the corresponding cloud map results under different working conditions as the output results of each functional module, and then form a standardized functional analysis module for each functional component;

[0186] A calculation module, which acquires the digital three-dimensional model of the functional components of the power tools of the table saw type, sets the surface feature information and load parameters obtained by the corresponding functional components interacting, so that the standardized functional analysis model of the corresponding functional component outputs the stress, strain and deformation data of the corresponding functional component, and converts them into the corresponding cloud map results.

[0187] Example 3

[0188] A numerical - calculation - based lightweight system for power tools, comprising:

[0189] One or more processors;

[0190] A storage device for storing one or more programs;

[0191] When the one or more programs are executed by the one or more processors, the one or more processors implement the above - mentioned numerical - calculation - based digital R & D method for power tool lightweighting.

[0192] Application Example 1

[0193] Strength analysis of the die - casting turntable of power tools.

[0194] The background of the digital verification project for the strength analysis of the die - casting turntable of power tools stems from the continuous improvement requirements for the performance and safety of power tools. With the expansion of the user group of power tools, from professional craftsmen to ordinary households, the portability, ease of use, and reliability of tools have become important considerations in design. As a key component in power tools, the strength and durability of the die - casting turntable are directly related to the performance and service life of the tool. However, the die - casting turntable needs to bear complex loads and torques during actual operation, which requires its design to meet specific technical requirements to ensure reliability and durability during operation. Therefore, through digital verification technologies such as finite - element analysis, performing strength analysis on the die - casting turntable and simulating its stress distribution and deformation under different working conditions are crucial for ensuring that its design meets safety standards and performance requirements. Such analysis can also help identify the weak links in the structure, provide a scientific basis for the structural optimization of the die - casting turntable, thereby improving its load - bearing capacity and overall stability, and ensuring the safety of users during use.

[0195] The specific implementation process of the application example is as follows: Input the geometric figure (digital 3D model) of the die - casting turntable into the standardized functional analysis model of the die - casting turntable constructed, and select the material of the die - casting turntable and its physical data types, as shown in Table 1 and Table 2.

[0196] Table 1

[0197]

[0198] Table 2

[0199]

[0200] In Table 2, is the density, is the elastic modulus, is the Poisson's ratio, is the yield strength, is the ultimate strength.

[0201] Set the surface feature information and load parameters (load position, magnitude, and direction) obtained from the interaction of corresponding functional components, as shown in Table 3.

[0202] Table 3

[0203]

[0204] Verify using the standardized functional analysis model of the die-casting turntable. The verification results are shown in Table 4. The result diagram is as Figure 2 shown, which is the deformation nephogram of the die-casting turntable. The judgment logic is as follows:

[0205] If the maximum stress value is less than the material yield strength, it can be determined that plastic deformation will not occur. Therefore, the reference suggestion is qualified.

[0206] When the maximum stress value is between the material yield strength and the ultimate strength, although plastic deformation will occur, it will not cause failure. At this time, the reference suggestion is a warning.

[0207] When the maximum stress value is greater than the material ultimate strength, failure is inevitable, and the reference suggestion is unqualified.

[0208] Table 4

[0209]

[0210] In Table 4, the standard value refers to the minimum yield strength among all materials, and the verification result value refers to the simulation result value.

[0211] Application Example 2

[0212] This application example is for the strength analysis of the rocker arm of an electric tool.

[0213] The digital verification report for the strength analysis of the rocker arm of an electric tool aims to simulate the stress distribution of the rocker arm under different load conditions through accurate and effective finite element analysis algorithms. As a key mechanical device in an electric tool, the main functions of the rocker arm include achieving rotation or swinging, transmitting power, supporting and fixing other components, and controlling the movement of other components. Therefore, ensuring the strength and stiffness of the rocker arm is the key to maintaining the performance and safety of the electric tool. In actual applications, the rocker arm needs to bear certain loads and torques, which requires the design of the rocker arm to meet specific technical requirements to ensure its reliability and durability during operation.

[0214] This scenario will simulate the maximum design load borne by the rocker arm in a static state according to the working standards of power tools to test its stress under uniformly distributed loads. By accurately setting the material properties, geometry, and boundary conditions of the rocker arm, various working conditions that may be encountered during actual use can be predicted. In the geometric modeling stage, a three-dimensional model was constructed by accurately describing the geometry of the rocker arm. The model takes into account every detail of the rocker arm, including its length, cross-sectional shape, connection points, and hole positions, etc. Each geometric feature will be represented in the data to ensure the accuracy of the model. Material property data also needs to be input, including elastic modulus, Poisson's ratio, and yield strength, etc., which are usually provided by experimental data or material standards. For example, assume that the rocker arm is made of aluminum alloy, with an elastic modulus of 70 GPa and a Poisson's ratio of 0.33. The boundary conditions are set with reference to the boundary settings related to the rocker arm in the previous text. In the load simulation stage, assume that the rocker arm is subjected to a uniformly distributed load, such as the load generated by the weight of the saw blade. In data processing, the uniformly distributed load can be distributed by the overall load size PPP according to length, area, or volume. Here, assume that the length of the rocker arm is 300 mm and the load size is 500 N. The magnitude of the uniformly distributed load is:

[0215]

[0216] This load q will be distributed over the entire stressed surface of the rocker arm. According to the geometry, the action of the load on each small area is solved by integration. In the analysis process, the finite element method (FEA) is used for discretization, and the rocker arm is divided into several finite elements. The stress, strain, displacement, and other states of each element will be calculated by a finite element solver. For example, by considering the material stiffness matrix and load matrix of each element, the displacement field and stress field are solved. The calculation of the displacement field and stress field is based on the following formulas:

[0217]

[0218] Among them, K is the stiffness matrix, U is the displacement vector, and F is the load vector. The solution of the stiffness matrix is based on the elastic modulus and geometric characteristics of the material, and the load vector is jointly determined by the uniformly distributed load and boundary conditions.

[0219] The stress field calculation uses the stress-strain relationship:

[0220]

[0221] Among them, is the stress, E is the elastic modulus of the material, is the strain. The strain is calculated through the displacement gradient, and the displacement gradient is combined with the shape function and nodal displacement to obtain the strain field. Finally, the stress field obtained by solving can be used to evaluate the stress distribution of the rocker arm under the uniformly distributed load and find out the possible high-stress areas.

[0222] Input the geometry of the rocker arm into the constructed standardized functional model of the rocker arm, select the material of the rocker arm and its physical numerical model, and set the surface feature information and load parameters (load position, magnitude, and direction) obtained from the interaction of the corresponding functional components, as shown in Table 5.

[0223] Table 5

[0224]

[0225] Run using the standardized functional model of the rocker arm, and the resulting output diagram is as Figure 3 shown, which is the deformation nephogram of the rocker arm.

[0226] Through these data processing processes and corresponding algorithms, the stress conditions that the rocker arm will withstand during actual use can be accurately predicted, helping engineers optimize the design and ensuring the reliability and durability of the rocker arm.

[0227] The report will detail the key parameters during the simulation, such as the stress distribution diagram, to ensure that the rocker arm design meets safety standards and performance requirements. In addition, by comparing the simulation results of different design schemes, the weak links of the structure can be identified, providing a scientific basis for the structural optimization of the rocker arm, thereby improving its load-bearing capacity and overall stability and ensuring the safety of users during use.

[0228] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art can still modify or equivalently replace the specific implementation manners of the present invention. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention shall be covered by the protection scope of the claims of the present invention.

Claims

1. A digital research and development method for lightweight electric tools based on numerical calculation, characterized in that: include: S1, decomposing table saw type power tools into different functional components according to their functions and connection relationships; S2, based on the finite element analysis method, builds standardized functional analysis modules for each functional component: Construct standardized functional modules for each functional component respectively; Assign materials to each functional module based on the physical material properties of each functional component; Form boundary constraints of each functional model according to the connection relationship of each functional component; Preset the direction and magnitude of load application according to the load conditions of each functional module, and preset the mapping relationship between the interactive feature surface and the load bearing surface; The stress, strain, deformation data and corresponding cloud map results under different working conditions are used as the output results of each functional module, thereby forming a standardized functional analysis module for each functional component; S3, obtain the digital three-dimensional model of the functional components of the table saw type power tool, set the surface feature information and load parameters obtained by the interaction of the corresponding functional components, so that the standardized function analysis module of the corresponding functional components outputs the stress, strain and deformation data of the corresponding functional components, and converts them into corresponding cloud map results.

2. The method for developing lightweight electric tools based on numerical calculation according to claim 1, characterized in that: The table saw type power tool is divided into five functional components according to the functional role and connection relationship, namely, a die-cast turntable, a rocker arm, a saw blade, a connecting head and a die-cast base, wherein the two ends of the die-cast base are respectively connected to the table top and the die-cast turntable, the two ends of the die-cast turntable are respectively connected to the die-cast base and the rocker arm, the two ends of the rocker arm are respectively connected to the die-cast turntable and the sliding rod, the two ends of the connecting head are respectively connected to the sliding rod and the saw head, and the saw blade is connected to the saw head.

3. The method for developing lightweight electric tools based on numerical calculation according to claim 2, characterized in that: Construct standardized functional analysis module of die-casting turntable based on finite element analysis method: Construct standardized functional modules for die-casting turntables; Assign material values ​​to the functional modules of the die-casting turntable according to the physical material properties of the die-casting turntable; The boundary constraints of the functional modules of the die-casting turntable are formed according to the connection relationship: the inner wall surface of the bolt hole at the bottom of the die-casting turntable is preset as the constraint surface, and the rotational degree of freedom and translational degree of freedom of the constraint surface are set, and the inner wall surface of the central axis where the turntable and the rocker arm are connected is set as the load-bearing surface; The direction and magnitude of the load are preset according to the load conditions of the functional modules of the die-casting turntable, and the mapping relationship between the interactive characteristic surface and the load bearing surface of the die-casting turntable is preset; Through numerical calculation method, the stress, strain and deformation data of the die-casting turntable under different working conditions are output, thereby forming a standardized functional analysis module for the die-casting turntable.

4. The method for developing lightweight electric tools based on numerical calculation according to claim 2, characterized in that: Construct a standardized functional analysis model of the rocker arm based on the finite element analysis method: Construct standardized functional modules for rocker arms; Assign materials to the functional modules of the rocker arm according to the physical material properties of the rocker arm; The boundary constraints of the functional module of the rocker arm are formed according to the connection relationship: the inner wall surface where the rocker arm is connected to the central axis of the turntable is preset as the constraint surface, and the rotational degree of freedom and translational degree of freedom of the constraint surface are set, and the inner wall surface of the hole where the rocker arm is connected to the slide rod is set as the load bearing surface; The direction and magnitude of the load are preset according to the load conditions of the functional modules of the rocker arm, and the mapping relationship between the interactive characteristic surface and the load bearing surface is preset; A nonlinear contact algorithm is used to output the stress, strain and deformation data of the rocker arm under different working conditions, thereby forming a standardized functional analysis module for the die-casting turntable.

5. The method for developing lightweight electric tools based on numerical calculation according to claim 2, characterized in that: Construct a functional analysis module for saw blade standardization based on finite element analysis: Construct functional modules for saw blade standardization; Assigning materials to the functional modules of the saw blade according to the physical material properties of the saw blade; The boundary constraints of the functional modules of the saw blade are formed according to the connection relationship: In the axial loading working mode, the outer edge of the saw blade is set as the constraint surface, all degrees of freedom of the constraint surface are restricted according to the numerical calculation method, the saw blade surface is set as the load bearing surface, and the saw blade axis direction is set as the force direction; In the sawtooth loading working condition mode, the inner wall surface of the saw blade center hole is preset as the constraint surface, the rotational degree of freedom and translational degree of freedom of the constraint surface are set, and the sawtooth surface is set as the load bearing surface; Preset the direction and magnitude of the load application according to the load conditions of the functional module of the saw blade, and preset the mapping relationship between the interactive characteristic surface and the load bearing surface; The numerical calculation method is used to output the stress, strain and deformation data of the saw blade under different working conditions, thereby forming a standardized functional analysis module for the saw blade.

6. The method for developing lightweight electric tools based on numerical calculation according to claim 2, characterized in that: Construct a standardized functional analysis module for connectors based on finite element analysis: Construct functional modules for connector standardization; Assigning materials to the functional modules of the connector according to the physical material properties of the connector; The boundary constraints of the functional modules that form the connectors are based on the connection relationships: The inner wall surface of the hole where the connector and the slide rod are connected is preset as a constraint surface, the rotational degree of freedom and the translational degree of freedom of the constraint surface are set, and the inner wall surface of the hole where the rocker arm and the slide rod are connected is set as a load bearing surface; Preset the direction and magnitude of the load application according to the load-bearing condition of the functional module of the connector, and preset the mapping relationship between the interactive characteristic surface of the connector and the load bearing surface; The numerical calculation method is used to output the stress, strain and deformation data of the connector under different working conditions, thereby forming a standardized functional analysis module for the connector.

7. The method for developing lightweight electric tools based on numerical calculation according to claim 2, characterized in that: Construct standardized functional analysis module of die-casting base based on finite element analysis method: Construct standardized functional modules for die-casting bases; Assign material values ​​to the functional modules of the die-casting base according to the physical material properties of the die-casting base; The boundary constraints of the die-casting base are formed according to the connection relationship: The contact surface of the support foot of the die-casting base is preset as a constraint surface, all degrees of freedom of the constraint surface are restricted, and the center surface of the die-casting base is set as a load-bearing surface as a fixed support; Preset the direction and magnitude of the load application according to the load-bearing condition of the functional module of the die-casting base, and preset the mapping relationship between the interactive characteristic surface of the die-casting turntable and the load-bearing surface; The numerical calculation method is used to output the stress, strain and deformation data of the die-casting turntable under different working conditions, thereby forming a standardized functional analysis module for the die-casting base.

8. The method for developing lightweight electric tools based on numerical calculation according to claim 1, characterized in that: Based on the acquired digital 3D model of the functional components of table saw power tools and the output stress, strain and deformation data of the corresponding functional components, and rendering in the Paraview open source environment, the stress and deformation distribution diagram of the corresponding functional components and the digital verification report are obtained.

9. A lightweight system for electric tools based on numerical calculation, characterized in that: include: Divide the modules and decompose the table saw power tools into different functional parts according to their functions and connection relationships; Building modules, based on finite element analysis method to build standardized functional analysis modules for each functional component: Construct standardized functional modules for each functional component respectively; Assign materials to each functional module based on the physical material properties of each functional component; Form boundary constraints of each functional model according to the connection relationship of each functional component; Preset the direction and magnitude of load application according to the load conditions of each functional module, and preset the mapping relationship between the interactive feature surface and the load bearing surface; The stress, strain, deformation data and corresponding cloud map results under different working conditions are used as the output results of each functional module, thereby forming a standardized functional analysis module for each functional component; The calculation module obtains the digital three-dimensional model of the functional components of the table saw type power tool, sets the surface feature information and load parameters obtained by the interaction of the corresponding functional components, so that the standardized functional analysis model of the corresponding functional components outputs the stress, strain and deformation data of the corresponding functional components, and converts them into corresponding cloud map results.

10. A lightweight system for electric tools based on numerical calculation, characterized in that: It includes: one or more processors; A storage device for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the lightweight digital research and development method of electric tools based on numerical calculation as described in any one of claims 1-8.

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