Electric tool lightweight digital research and development method and system based on numerical calculation

Abstract

The invention provides an electric tool lightweight digital research and development method and system based on numerical calculation, belongs to the field of electric tool optimization, and provides the electric tool lightweight digital research and development method based on numerical calculation aiming at the obvious limitation in the research and development of existing bench saw type electric tools. The bench saw type electric tool is divided into different functional parts; constructing a standardized functional analysis module of each functional component based on a finite element analysis method; a digital three-dimensional model of a bench saw type electric tool functional part is obtained, surface feature information and load parameters obtained through interaction of the corresponding functional part are set, and stress, strain and deformation data of the corresponding functional part are output and converted into corresponding cloud picture results. According to the application, each functional part of the electric tool is modularized, different application scenes and customer requirements can be adapted and verified, the pre-processing setting difficulty of finite element analysis is reduced, the cost and the technical threshold can be reduced, and the research and development period is shortened.

Description

Technical Field

[0001] The present invention belongs to the field of power tool optimization, and in particular relates to a lightweight digital research and development method and system for power tools based on numerical calculation. Background Art

[0002] With the continuous advancement of technology and the increasing diversification of market demand, the research and development of table saw power tools has gradually developed towards modularization. This trend not only improves the flexibility and adaptability of products, but also greatly shortens the product development cycle and meets the market's demand 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 demand for digital R&D. Especially in the market environment where power tool products are rapidly iterating and gradually customized, small and medium-sized enterprises are facing tremendous pressure. They need a more efficient and flexible R&D system to cope with the large-scale replacement and optimization needs every year.

[0004] In the current research and development of table saw power tools, traditional technical solutions mainly rely on the trial and error method of mechanical engineers. The core of this method is to gradually optimize the design through continuous experimentation and error, but this process has significant defects. First, the trial and error method requires repeated product proofing design, and each design iteration requires the actual manufacture of a prototype, which not only consumes time, but also consumes materials and human resources, and also prolongs the research and development cycle.

[0005] Simulation engineers use simulation to conduct digital R&D. Although this method can theoretically reduce the need for physical prototypes, it also has its drawbacks. The simulation process needs to rely on a lot of human experience, which means that the accuracy of the results depends largely on the professional level and experience of the operator. In addition, the hardware cost of local simulation calculations is high and the calculation time is long, which is a considerable burden for small and medium-sized enterprises. The high technical difficulty and high requirements on the user's knowledge level limit the scope of application and popularity of simulation technology. The licensing fees for simulation software are 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 research and development of table saw power tools. The cost and time consumption of trial and error, as well as the high threshold and cost of simulation technology, have restricted the efficiency of research and development and the speed of innovation. These problems highlight the need for a lightweight research and development method and system that should be able to reduce costs, shorten the research and development 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 response to the problems of the prior art, the present invention provides a digital R&D method and system for lightweight electric tools based on numerical calculation, aiming to provide a digital solution that is cost-effective, easy to implement and operate. This application will integrate modular design concepts and achieve rapid conversion from conceptual design to product prototype through digital tools and platforms.

[0008] This application provides a digital research and development method for lightweight electric tools based on numerical calculation, including: 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; Among them, the boundary constraints include the constraints of the boundary surface, degree of freedom, force surface and force direction of each functional model. The input quantity of the model includes quantitative and variable. 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 characteristic surface, the load size of the functional module and the load force surface characteristics are variables. 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 functional 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 to realize the strength analysis of the obtained functional components.

[0009] The interactive feature surface and the load-bearing surface are mapped to each other. The mapping relationship between the two is mainly reflected in the existence of specific matching in geometric shapes and the consistency of boundary constraint relationships. The purpose of this setting is to facilitate the subsequent acquisition of the digital three-dimensional model of the functional components of table saw power tools to be able to quickly form a link with the standardized functional analysis modules of each functional component constructed, so as to facilitate subsequent processing.

[0010] The constructed standardized functional model is a universal model. Users can select and set surface feature information so that the connection relationship of the acquired digital geometric model is fixed. Then, the stress, strain and deformation under the set load can confirm the analysis results of the digital three-dimensional model of the input table saw power tool functional components.

[0011] The prior art usually builds a model of the entire power tool, rather than modeling each functional component of the power tool separately. This results in the need for overall simulation when changing some working conditions, which takes a long time and is inefficient. The invention of this application is to modularize the various functional components of table saw power tools to facilitate the combination and reconfiguration of different components to adapt to and verify different application scenarios and customer needs. In addition, it can also facilitate data management and sharing.

[0012] In this application, the functional components of the power tool are separated, and the connection relationship between the functional components forms the constraints of the functional model, which can realize the separate modeling of each functional component. When one or several functional modules are changed separately, the working state under different working conditions can be obtained, which reduces the difficulty of setting the pre-processing of finite element analysis. This method can also 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.

[0013] Furthermore, the table saw type power tool is divided into five functional components for key analysis according to their functional roles and connection relationships, namely, a die-cast turntable, a rocker arm, a saw blade, a connecting head and a die-cast base, wherein two ends of the die-cast base are respectively connected to the table top and the die-cast turntable, two ends of the die-cast turntable are respectively connected to the die-cast base and the rocker arm, two ends of the rocker arm are respectively connected to the die-cast turntable and the sliding rod, 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.

[0014] Furthermore, a standardized functional analysis module for die-casting turntables is constructed based on the 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.

[0015] Furthermore, a standardized functional analysis model of the rocker arm is constructed 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.

[0016] Furthermore, a functional analysis module for saw blade standardization is constructed based on the finite element analysis method: 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.

[0017] Furthermore, a standardized functional analysis model of the connector is constructed based on the finite element analysis method: 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.

[0018] Furthermore, a standardized functional analysis module for the die-casting base is constructed based on the 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; According to the load conditions of the functional modules of the die-casting base, the direction and magnitude of the load are preset, and the mapping relationship between the interactive characteristics of the die-casting turntable and the load bearing surface is preset; 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.

[0019] Furthermore, 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, the stress and deformation distribution diagram of the corresponding functional components and the digital verification report are obtained by rendering in the Paraview open source environment. The stress, strain and deformation data are converted into corresponding cloud map results to form stress distribution diagrams and analysis reports, which can help engineers obtain intuitive data.

[0020] A lightweight system for electric tools based on numerical calculation, comprising: 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 interaction characteristics 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; 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.

[0021] A lightweight system for electric tools based on numerical calculation, comprising: 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 above-mentioned digital research and development method for lightweight electric tools based on numerical calculation.

[0022] Beneficial effects: This application is a lightweight digital R&D method and system for electric tools based on numerical calculations, which modularizes the various functional components of electric tools to facilitate the combination and reconfiguration of different components to adapt to and verify different application scenarios and customer needs. The connection relationship between the various functional components forms the constraints of the functional model, which can realize the separate modeling of each functional component and reduce the difficulty of setting up the pre-processing of finite element analysis. This method can also 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the process of Example 1; Figure 2 It is a schematic diagram of the results of application example 1; Figure 3 This is a schematic diagram of the results of Application Example 2. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with 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 intended to limit the present invention.

[0025] In the specific solution of this application, a modular table saw type power tool lightweight R&D system is proposed, which aims to assist engineers to complete the R&D tasks of most parts through standardized solutions. The core of this system lies in its five modules, each of which performs strength analysis on key parts of power tools to ensure the reliability and optimization of the design.

[0026] Example 1 This embodiment provides a digital research and development method for lightweight electric tools based on numerical calculation, and the flow chart is as follows: Figure 1 As shown, the specific process includes: S1, deconstructing table saw-type power tools into different functional components according to their functional roles and connection relationships; the table saw-type power tools are divided into five functional components for key analysis, namely, a die-cast turntable, a rocker arm, a saw blade, a connector 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 connector are respectively connected to the sliding rod and the saw head, and the saw blade is connected to the saw head; each module aims to provide a standardized solution to assist engineers in efficiently completing R&D tasks.

[0027] S2, based on the finite element analysis method, builds standardized functional analysis modules for each functional component: In this embodiment, the boundary constraints include the constraints of the boundary surfaces, degrees of freedom, force 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 modules are quantitative, and the material assignments of the functional modules, the boundary constraint mapping characteristic surfaces, the load sizes and load force surface characteristics of the functional modules are variables.

[0028] S2.1, construct a standardized functional analysis module for die-casting turntables based on finite element analysis: 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 process of setting the rotational and translational degrees of freedom includes: The z-axis rotational freedom (i.e., the rotation of the turntable around the axis of the bolt hole) is set according to the rotation matrix; the rotation matrix expression is:

[0029] in, It 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 turntable surface, and the transformed coordinates are obtained after conversion to ensure that the rotation state of the turntable can be accurately simulated; In addition to releasing the rotational freedom of the Z axis, the module also limits the other five degrees of freedom of the inner wall of the bolt hole, including the translational freedom of the X axis, Y axis and Z axis, as well as the rotational freedom of the X axis and Y axis, to ensure the accuracy of the simulation. The translational freedom of the x axis and y axis and the rotational freedom of the x axis and y axis are set according to the constraint equation. The constraint equation is:

[0030] in, , , represents the translational degrees of freedom of the X, Y, and Z axes, , Indicates the rotational freedom about the X and Y axes.

[0031] In order to more realistically reflect the load conditions of the overall structure under actual working conditions, the inner wall surface of the central axis connecting the turntable and the rocker arm was selected as the load-bearing surface, and the force direction was controlled to the standard gravity direction.

[0032] 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; The distribution of load in the Z-axis direction can be expressed as:

[0033] in, ρ is the material density, g is the gravitational acceleration, and A(x,y) is the area distribution function of the force-bearing surface on the x,y plane. Through the numerical integration method, the load value of each point on the force-bearing surface can be obtained and applied to the finite element model of the turntable surface for stress and deformation analysis.

[0034] The formula based on the turntable geometry and the load distribution is:

[0035] in, is the vector from the force application point to the center of the turntable, is the force acting on the point, dA is a small area element on the force-bearing surface, and the moment M represents the force condition of the turntable. In actual calculations, the load distribution will be discretized according to the shape characteristics and working state of the turntable, and the distribution diagram of the moment and stress is calculated by numerical calculation method, so as to accurately simulate the force condition of the turntable in actual work.

[0036] The force direction is set to the standard gravity direction. The load value of each point on the force surface is obtained through the numerical integration method. 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.

[0037] Through numerical calculation method, the stress, strain value and stress distribution diagram of the die-casting turntable under different working conditions are output, thereby forming a standardized functional analysis module for the die-casting turntable.

[0038] S2.2, construct a standardized functional model of the rocker arm based on finite element analysis: Construct a standardized functional analysis module 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 each functional model are formed according to the connection relationship: the inner wall surface connecting the rocker arm and the central axis of the turntable is preset as the constraint surface, and the rotational freedom and translational freedom of the constraint surface are set, and the inner wall surface of the hole where the rocker arm and the slide bar are connected is set as the load-bearing surface; the inner wall surface connected to the central axis of the turntable (the central axis is set as the Z-axis rotational freedom of this component) is set as the constraint application surface, limiting five degrees of freedom (X-axis translational freedom, Y-axis translational freedom, Z-axis translational freedom, X-axis rotational freedom and Y-axis rotational freedom) to ensure the stability of the rocker arm. This process can be achieved through the following constraint equations:

[0039] in, , , represents the translational degrees of freedom of the X, Y, and Z axes, , Indicates the rotational freedom about the X and Y axes.

[0040] 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; According to the material properties, contact area and relative motion between the slide bar and the rocker arm, the length of the slide bar is more important. The coupling point simulates the action of the slide bar, applies force to the coupling point, sets the coupling point for force transmission, and sets the force coupling point by the rod length provided by the engineer (along the slide bar direction, the distance is the input rod length value). By applying downward force to the coupling point and transmitting it to the load-bearing surface, the force situation in actual work is simulated. Specifically, the calculation of the force at the coupling point depends on the following formula:

[0041] in, is the force at the coupling point, and k is the coupling coefficient, which is determined by factors such as the coupling system velocity and is fitted by experimental data or material parameters (specifically, it is analyzed in the finite element analysis model and obtained by calculation). This coefficient ensures that the input pressure can be accurately transmitted to the coupling point and further act on the force-bearing surface.

[0042] The dynamic response of the contact surface and contact point is processed using a nonlinear contact algorithm. The calculation of the contact force depends on the contact stiffness matrix. The deformation of the contact point is described by the following equation:

[0043] in, is the deformation of the contact point, is the force applied to the contact point, and K is the contact stiffness matrix. The algorithm iteratively updates the position and state of the contact point to ensure that the mechanical transmission between the force-bearing surface and the coupling point meets the actual working conditions during the simulation. This digitized process enhances the accuracy of the rocker arm strength analysis and provides strong support for optimized design.

[0044] The above-mentioned nonlinear contact algorithm is used to obtain the stress, strain and deformation data of the rocker arm under different working conditions.

[0045] S2.3, construct a functional analysis module for saw blade standardization based on finite element analysis: Construct a standardized functional analysis module for saw blades; 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 mode, the outer edge of the saw blade is set as the constraint surface. All degrees of freedom of the constraint surface are limited 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 axial loading mode, the load direction is usually determined by the saw blade axis direction, and the direction vector is used. Indicates the load direction. The numerical calculation of the load is achieved through the following formula:

[0046] Where P is the magnitude of the applied load, is the load direction vector, and The calculation is defined by the geometric relationship between the axis and the load application surface.

[0047] 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, the sawtooth surface is set as the load force surface, and the force direction is set; In the sawtooth loading mode, the load direction defaults to the combined normal vector of the selected surface or surface combination on the side of the saw blade. The load is calculated numerically through the surface normal vector And the combination of payload size P is achieved:

[0048] in, is the normal vector of the selected surface or surface combination, and P is the load size. 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 digital processing method achieves a reasonable distribution of loads through numerical solution, thereby effectively simulating the force conditions of the saw blade in actual work.

[0049] When loading the sawtooth, the constraint is fixed on the inner wall of the saw blade center hole, the load is applied to the sawtooth surface, and the load direction defaults to the comprehensive normal vector of the selected surface or surface combination on the side of the saw blade; the load magnitude 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 digitized processing method achieves a reasonable distribution of the load through numerical solution, thereby effectively simulating the force conditions of the saw blade in actual work.

[0050] 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 above numerical calculation method is used to output the stress, strain and deformation data of the saw blade under different working conditions.

[0051] S2.4, construct a standardized functional analysis model of the connector based on the finite element analysis method: 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; The constraint part of this part is located at the inner wall of the hole connected to the slide rod. Since the connector and the saw head housing are connected by bolts (the central axis is set as the Z axis), the five degrees of freedom (X-axis translational freedom, Y-axis translational freedom, Z-axis translational freedom, X-axis rotational freedom and Y-axis rotational freedom) of the inner wall of the bolt axis connecting the connector and the saw head are set during this part of the setting process, and the Z-axis rotational freedom is released. This process can be achieved through the following constraint equations:

[0052] in, , , represents the translational degrees of freedom of the X, Y, and Z axes, , Indicates the rotational freedom of the X and Y axes. The load is applied to the corresponding saw head handle and the load direction is assumed to be the direction of gravity.

[0053] 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.

[0054] S2.5, constructing a standardized functional analysis module for die-casting bases based on finite element analysis: 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.

[0055] The main purpose is to perform static pressure simulation on the die-casting base. The supporting feet of the die-casting 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-casting base in the direction of gravity.

[0056] 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 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.

[0057] The analysis results are accurately converted into the widely supported VTK visualization file format by post-processing results in the Paraview open source environment for rendering and display. It provides stress and deformation distribution diagrams of the power tool die-casting turntable under working conditions and issues corresponding digital verification reports, providing engineers with intuitive analysis results.

[0058] When constructing each standardized functional model based on the finite element analysis method, the model is corrected by the measured data to ensure the accuracy of the model. The specific means 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. During the collection, the real-time electrical signal is collected through eddy current, and the fast Fourier transform (FFT) algorithm is used to obtain the frequency and distribution of the electrical signal (sine harmonics of different frequencies); the Fourier transform formula is:

[0059] 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; Based on the frequency and distribution of the electrical signal (sine harmonics of different frequencies), the phase is extracted according to the phase demodulation method; the frequency component and phase information of the signal can be obtained through Fourier transform. The phase demodulation technology relies on the analysis of this phase information. The formula for phase extraction can be expressed as:

[0060] in, is the frequency component The phase angle at Represents the phase of a complex number.

[0061] According to the phase changes at different time points, the extreme value and difference of displacement are calculated, and the displacement change The calculation formula is:

[0062] in, and Respectively in time and The phase of It is the frequency component related to the displacement change. And the extreme value and difference of displacement are obtained based on it.

[0063] The constructed finite element model adopts unstructured mesh generation algorithms, including the Delaunay method and the Advancing-Front method (wavefront method), to ensure that the mesh properties can be dynamically adjusted during the generation process, with good controllability and good quality of the final generated mesh.

[0064] The Delaunay triangulation used is a triangulation method based on the Delaunay condition, that is, for any triangle in the triangulation, its circumscribed circle should not contain any other points. This method can ensure that the generated triangle is as close to an equilateral triangle as possible, thereby improving the quality of the mesh.

[0065] Algorithm steps: 1. Start with a large triangle that contains all the points.

[0066] 2. Insert the points into the triangulation one by one. Each time you insert a point, check whether the point is within the circumcircle of the existing triangle.

[0067] 3. If the point is within the circumcircle of a triangle, split the triangle into three new triangles so that the new point becomes the vertex of one of the triangles.

[0068] 4. Repeat the above steps until all points have been inserted.

[0069] The Advancing-Front method is a layer-by-layer mesh generation method that starts from an initial boundary and gradually expands inward to form new mesh units. Algorithm steps: 1. Define an initial boundary, usually the geometric boundary of the problem.

[0070] 2. Select a point on the boundary as the vertex of the new triangle.

[0071] 3. Select an edge from the border and connect it with the new vertex to form a new triangle.

[0072] 4. Update the boundary and add the opposite side of the newly formed triangle to the boundary.

[0073] 5. Repeat the above steps until all areas are meshed.

[0074] The connection between the turntable and the rocker arm is realized through the central axis bolt. This connection state is set as a fixed connection between the geometric bodies, with the turntable as the fixed target and the rocker arm as the contact target, and a coordinate system based on the central axis of the two is automatically generated. This involves determining the position and direction of the connection point. The following formula can be used to define the origin and direction of the coordinate system:

[0075]

[0076] in, is the position vector of the origin of the coordinate system, is a unit vector along the medial axis; is the position vector of the center of gravity of the turntable geometry, is the position vector of the center of gravity of the rocker arm geometry.

[0077] Example 2 A lightweight system for electric tools based on numerical calculation, comprising: 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 functional modules for each functional component separately; 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 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.

[0078] Example 3 A lightweight system for electric tools based on numerical calculation, comprising: 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 above-mentioned digital research and development method for lightweight electric tools based on numerical calculation.

[0079] Application Example 1 Strength analysis of die-cast turntable for power tools.

[0080] The background of the digital verification project for the strength analysis of die-cast turntables for power tools stems from the continuous improvement of the performance and safety requirements of power tools. With the expansion of the user group of power tools, from professional craftsmen to ordinary families, the portability, ease of use and reliability of the tools have become important design considerations. As a key component in power tools, the strength and durability of the die-cast turntable are directly related to the performance and service life of the tool. However, the die-cast turntable needs to withstand complex loads and torques in actual work, which requires its design to meet specific technical requirements to ensure reliability and durability during the working process. Therefore, it is crucial to conduct strength analysis on the die-cast turntable through digital verification technologies such as finite element analysis, and simulate its stress distribution and deformation under different working conditions to ensure that its design meets safety standards and performance requirements. Such analysis can also help identify the weak links of the structure and provide a scientific basis for the structural optimization of the die-cast turntable, thereby improving its load-bearing capacity and overall stability, and ensuring the safety of users during use.

[0081] The specific implementation process of the application example is: input the geometry of the die-casting turntable (digital three-dimensional model) into the constructed standardized functional analysis model of the die-casting turntable, and select the material of the die-casting turntable and its physical numerical type, as shown in Tables 1 and 2.

[0082] Table 1

[0083] Table 2

[0084] In Table 2, is the density, is the elastic modulus, is Poisson's ratio, is the yield strength, For ultimate strength.

[0085] The surface feature information and load parameters (load position, size and direction) obtained by interaction with the corresponding functional components are set, as shown in Table 3.

[0086] Table 3

[0087] The standardized functional analysis model of the die-casting turntable was used for verification, and the verification results are shown in Table 4. Figure 2 As shown in the figure, it is the deformation cloud diagram of the die-casting turntable. The judgment logic is as follows: If the maximum stress value is less than the yield strength of the material, it can be determined that no plastic deformation will occur, so the reference recommendation is qualified.

[0088] When the maximum stress value is between the yield strength and the ultimate strength of the material, although plastic deformation will occur, it will not cause damage. At this time, the reference recommendation is a warning.

[0089] When the maximum stress value is greater than the ultimate strength of the material, damage is inevitable and the reference recommendation is unqualified.

[0090] Table 4

[0091] In Table 4, the standard value refers to the minimum yield strength of all materials, and the verification result value refers to the simulation result value.

[0092] Application Example 2 This application example is the strength analysis of the power tool rocker arm.

[0093] The digital verification report of the strength analysis of the power tool rocker arm is designed to simulate the stress distribution of the rocker arm under different load conditions through an accurate and effective finite element analysis algorithm. As a key mechanical device in the power tool, the rocker arm's main functions include realizing rotation or swinging, transmitting power, supporting and fixing other components, and controlling the movement of other components. Therefore, ensuring the strength and rigidity of the rocker arm is the key to maintaining the performance and safety of the power tool. In actual applications, the rocker arm needs to withstand certain loads and torques, which requires that the design of the rocker arm must meet specific technical requirements to ensure its reliability and durability during the working process.

[0094] This scenario will simulate the maximum design load that the rocker arm bears in a static state according to the working standard of the power tool to test its stress under uniformly distributed load. By accurately setting the material properties, geometry and boundary conditions of the rocker arm, various working conditions that the rocker arm may encounter in actual use can be predicted. In the geometric modeling stage, a three-dimensional model is 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. Each geometric feature will be represented in the data to ensure that the model is accurate. Material property data also needs to be input, including elastic modulus, Poisson's ratio and yield strength, which are usually provided by experimental data or material standards. For example, assume that the rocker arm uses aluminum alloy with an elastic modulus of 70 GPa and a Poisson's ratio of 0.33. The boundary conditions are set in accordance with the boundary settings related to the rocker arm in the previous article. In the load simulation stage, it is assumed 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, uniformly distributed loads can be distributed by distributing the overall load size PPP by length, area or volume. Here we assume that the rocker arm length is 300 mm and the load size is 500 N. The size of the uniformly distributed load is:

[0095] This load q will be distributed on the entire load-bearing surface of the rocker arm, and the effect of the load on each small area will be solved by integration according to the geometric shape. During the analysis, the finite element method (FEA) is used for discretization to divide the rocker arm into several finite units. The stress, strain, and displacement states of each unit will be calculated by the finite element solver. For example, by considering the material stiffness matrix and load matrix of each unit, the displacement field and stress field are solved. The calculation of the displacement field and stress field is based on the following formula:

[0096] 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 properties of the material, and the load vector is determined by the uniform load distribution and boundary conditions.

[0097] The stress field calculation uses the stress-strain relationship:

[0098] in, is the stress, E is the elastic modulus of the material, is the strain. The strain is calculated by the displacement gradient, which is combined with the shape function and the node displacement to obtain the strain field. Finally, the stress field obtained by solving can evaluate the stress distribution of the rocker arm under uniform load and find possible high stress areas.

[0099] The geometric figure of the rocker arm is input into the standardized functional model of the constructed rocker arm, the material of the rocker arm and its physical numerical type are selected, and the surface feature information and load parameters (load position, size and direction) obtained by the interaction of the corresponding functional components are set, as shown in Table 5.

[0100] Table 5

[0101] The standardized function model of the rocker arm is used for operation, and the output result is as shown in the figure Figure 3 As shown, it is the deformation cloud diagram of the rocker arm.

[0102] Through these data processing processes and corresponding algorithms, the stress conditions that the rocker arm will withstand in actual use can be accurately predicted, helping engineers optimize the design and ensure the reliability and durability of the rocker arm.

[0103] The report will record the key parameters of the simulation process in detail, such as stress distribution diagrams, 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.

[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field can still modify or replace the specific implementation methods of the present invention with equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be included in the scope of protection 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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