Real-time cutting force calculation method and device based on cutting simulation

Abstract

The invention belongs to the technical field of cutting machining, and relates to a real-time cutting force calculation method and device based on cutting simulation. Boolean operation is conducted on the tool and the Dexcel model of the to-be-machined workpiece, the cutting length of each Dexcel segment of the to-be-machined workpiece is obtained, and the cutting volume of the tool location point of the tool is obtained through calculation based on the cutting lengths of all the Dexcel segments of the to-be-machined workpiece; each cutter tooth is divided into M cutting edge infinitesimal elements, and the lag angle of the cutter at the axial cutting depth h is calculated; calculating the radial contact angle at each cutting edge infinitesimal element on each cutter tooth and the cutting thickness on the to-be-processed workpiece; calculating tangential, radial and axial cutting force infinitesimal elements acting on each cutting edge infinitesimal element; performing coordinate transformation on the tangential, radial and axial cutting force infinitesimal elements to obtain cutting force components of the cutting edge infinitesimal elements on x, y and z axes; and integrating the cutting edge components of all the cutting edge infinitesimal elements to obtain the instantaneous cutting force acting on the cutter.

Description

Technical Field

[0001] The present invention relates to the technical field of cutting processing, and in particular to a real-time cutting force calculation method and device based on cutting simulation. Background Art

[0002] Cutting force is one of the important physical quantities in milling, which directly affects the dimensional machining accuracy and surface integrity of the workpiece, thereby affecting the workpiece machining quality. Cutting force modeling refers to the description and prediction of the mechanical behavior of the cutting process through mathematical models or experimental methods during the workpiece cutting process, that is, using the cutting force model to calculate the cutting force during the machining process, thereby optimizing the cutting parameters (cutting speed, feed speed, cutting depth, etc.) to achieve accurate machining of the workpiece. Therefore, the accuracy of the cutting force calculation results is crucial to the machining accuracy and quality of the workpiece.

[0003] Experts and scholars at home and abroad have proposed empirical fitting models and machine learning models of empirical methods. By obtaining a large amount of cutting force experimental data, including cutting conditions (such as cutting depth, feed speed, tool material and workpiece material, etc.) and their corresponding cutting force values, the collected data are cleaned to ensure data quality, and then the features related to the cutting force are selected from multiple cutting conditions, and these features are combined or transformed to obtain a data set. Finally, the data in the data set are used to optimize the empirical formula (such as the linear regression model of the cutting force) or the machine learning model to obtain a cutting force prediction model. During the cutting process, the cutting conditions are input into the cutting force prediction model to output the corresponding cutting force value. However, this method is too dependent on the collected cutting force experimental data and needs to be based on a large number of cutting experiments and their result processing. The time cost and material cost are both high. In addition, since the cutting force is affected by multiple factors, and the relationship between these factors may be nonlinear or highly interactive, the model cannot accurately capture the correlation between all influencing factors. Especially when the coverage of the data set is limited, the cutting force accuracy output by the model will also decrease.

[0004] In summary, the existing cutting force calculation methods use empirical fitting models and machine learning models to predict the cutting force values ​​during the cutting process. They need to be based on a large number of cutting experiments and their result processing, with high time and material costs. In addition, they cannot fully capture the correlation between the various parameters that affect the cutting force, resulting in low accuracy of the cutting force values, which in turn affects the machining quality of the workpiece. Summary of the invention

[0005] To this end, the technical problem to be solved by the present invention is to overcome the problem that the cutting force calculation method in the prior art needs to be based on a large number of cutting experiments and their result processing, has high time and material costs, and cannot fully capture the correlation between various parameters affecting the cutting force, resulting in low accuracy of the cutting force value, thereby affecting the processing quality of the workpiece.

[0006] In order to solve the above technical problems, the present invention provides a real-time cutting force calculation method based on cutting simulation, comprising: The tool and the workpiece to be processed are discretized using the Tri-Dexel model to obtain the Dexel model of the tool and the Dexel model of the workpiece to be processed; Performing Boolean operations on the Dexel model of the tool and the Dexel model of the workpiece to be processed to obtain the cutting length on each Dexel segment of the workpiece to be processed, and calculating the cutting volume of the tool position point of the tool based on the cutting lengths on all Dexel segments of the workpiece to be processed; The axial cutting depth and the radial cutting depth are obtained based on the cutting volume of the tool position point of the tool, each tool tooth of the tool is divided into M cutting edge micro-elements along the tool axis direction, and the hysteresis angle of the tool at the axial cutting depth h is calculated based on the cutting edge helix angle and tool radius of the tool; Based on the cutting pitch angle between adjacent cutting edge micro-elements on each tooth, the angular displacement at the end point of the first cutting edge micro-element and the hysteresis angle of the tool at the axial cutting depth h, the radial contact angle at each cutting edge micro-element on the tooth is calculated; Based on the radial contact angle at each cutting edge microelement and the feed per tooth of the tool, the cutting thickness of the cutting edge microelement on the workpiece to be processed is calculated; based on the cutting thickness of the cutting edge microelement on the workpiece, the tangential plowing force coefficient, the radial plowing force coefficient, the axial plowing force coefficient and the unit step function, the tangential cutting force microelement, the radial cutting force microelement and the axial cutting force microelement acting on the cutting edge microelement are calculated using the instantaneous rigid force formula; The tangential cutting force element, radial cutting force element and axial cutting force element on each cutting edge element are converted to the spatial coordinate system to obtain the cutting force component in the x-axis direction, the cutting force component in the y-axis direction and the cutting force component in the z-axis direction of each cutting edge element; The cutting force component in the x-axis direction, the cutting force component in the y-axis direction, and the cutting force component in the z-axis direction of each cutting edge microelement on all the teeth of the tool are integrated to obtain the instantaneous cutting force in the x-axis direction, the instantaneous cutting force in the y-axis direction, and the instantaneous cutting force in the z-axis direction acting on the tool.

[0007] Preferably, the Dexel model of the tool includes the x-axis unidirectional Dexel model, y-axis unidirectional Dexel model and z-axis unidirectional Dexel model of the tool; the Dexel model of the workpiece to be processed includes the x-axis unidirectional Dexel model, y-axis unidirectional Dexel model and z-axis unidirectional Dexel model of the workpiece to be processed.

[0008] Preferably, a Boolean operation is performed on the Dexel model of the tool and the Dexel model of the workpiece to be processed to obtain the cutting length on each Dexel segment of the workpiece to be processed, and the cutting volume of the tool position point of the tool is calculated based on the cutting length on all Dexel segments of the workpiece to be processed, including: Boolean operations are performed on the x-axis unidirectional Dexel model of the tool and the x-axis unidirectional Dexel model of the workpiece to be processed to obtain the cutting length of each Dexel segment in the x-axis direction of the workpiece to be processed; the cutting volume of the workpiece to be processed under the x-axis perspective is calculated based on the cutting lengths of all Dexel segments in the x-axis direction of the workpiece to be processed; Perform Boolean operations on the y-axis unidirectional Dexel model of the tool and the y-axis unidirectional Dexel model of the workpiece to be processed to obtain the cutting length of each Dexel segment in the y-axis direction of the workpiece to be processed; calculate the cutting volume of the workpiece to be processed from the y-axis perspective based on the cutting lengths of all Dexel segments in the y-axis direction of the workpiece to be processed; Boolean operations are performed on the z-axis unidirectional Dexel model of the tool and the z-axis unidirectional Dexel model of the workpiece to be processed to obtain the cutting length of each Dexel segment in the z-axis direction of the workpiece to be processed; the cutting volume of the workpiece to be processed under the z-axis perspective is calculated based on the cutting lengths of all Dexel segments in the z-axis direction of the workpiece to be processed; The cutting volume of the tool position point of the tool is obtained based on the average of the cutting volume of the workpiece to be processed under the x-axis perspective, the cutting volume under the y-axis perspective, and the cutting volume under the z-axis perspective.

[0009] Preferably, after obtaining the instantaneous cutting force in the x-axis direction / the instantaneous cutting force in the y-axis direction / the instantaneous cutting force in the z-axis direction acting on the tool, the method further comprises: The average instantaneous cutting force in the x-axis direction, the average instantaneous cutting force in the y-axis direction and the average instantaneous cutting force in the z-axis direction of the tool are calculated respectively under a plurality of preset feed rates per tooth; The least squares method is used to perform linear fitting on the average x-axis instantaneous cutting force, the average y-axis instantaneous cutting force and the average z-axis instantaneous cutting force under all preset feed rates per tooth to obtain the cutting force coefficient of the tool.

[0010] Preferably, the calculation formula of the hysteresis angle of the tool at the axial cutting depth h is: , in, Indicates the axial cutting depth of the tool The hysteresis angle at Indicates cutting depth; Indicates the helix angle of the cutting edge of the tool; Indicates the tool radius.

[0011] Preferably, the calculation formula of the radial contact angle at each cutting edge microelement on the cutter tooth is: , , in, Indicates The first tooth Radial contact angle at each cutting edge microelement; represents the angular displacement at the end point of the first cutting edge microelement; Indicates the cutting pitch angle between connected cutting edges; Indicates the helix angle of the cutting edge of the tool; Indicates the tool radius; Indicates the thickness of the cutting edge microelement; Indicates the number of teeth.

[0012] Preferably, the calculation formula for the cutting thickness of the cutting edge microelement on the workpiece to be processed is: , in, Indicates The first tooth The cutting thickness of each cutting edge element on the workpiece to be processed; Indicates the feed per tooth of the tool; Indicates The first tooth Radial contact angle at each cutting edge microelement; The calculation formula of the tangential cutting force element on the cutting edge element is: , , in, Indicates The first tooth The tangential cutting force element on the cutting edge element; represents the unit step function; Indicates the tool cutting angle; Indicates the tool cutting angle; represents the tangential shear force coefficient; represents the tangential plowing force coefficient; The calculation formula of the radial cutting force element on the cutting edge element is: , in, Indicates The first tooth Radial cutting force element on each cutting edge element; represents the radial shear coefficient; represents the radial plowing force coefficient; The calculation formula of the axial cutting force element on the cutting edge element is: , in, Indicates The first tooth The axial cutting force element on each cutting edge element; represents the axial shear coefficient; Represents the axial plowing force coefficient.

[0013] Preferably, the cutting force component of the cutting edge microelement in the x-axis direction is expressed as: , in, Indicates The first tooth The cutting force component of the cutting edge microelement in the x-axis direction; Indicates The first tooth The tangential cutting force element on the cutting edge element; Indicates The first tooth Radial contact angle at each cutting edge microelement; Indicates The first tooth Radial cutting force element on each cutting edge element; The target radial cutting force element on the cutting edge element is expressed as: , in, Indicates The first tooth The cutting force component of the cutting edge microelement in the y-axis direction; The target axial cutting force element on the cutting edge element is expressed as: , in, Indicates The first tooth The cutting force component of the cutting edge microelement in the z-axis direction; Indicates The first tooth The axial cutting force element on the cutting edge element.

[0014] Preferably, the calculation formula of the instantaneous cutting force in the x-axis direction acting on the tool is: , in, It represents the instantaneous cutting force in the x-axis direction acting on the tool; Indicates the number of teeth; Indicates The first tooth The tangential cutting force element on the cutting edge element; No. The first tooth Radial contact angle at each cutting edge microelement; Indicates The first tooth Radial cutting force element on each cutting edge element; The calculation formula of the instantaneous cutting force in the y-axis direction acting on the tool is: , in, It represents the instantaneous cutting force in the y-axis direction acting on the tool; The calculation formula for the instantaneous cutting force in the z-axis direction acting on the tool is: , in, It represents the instantaneous cutting force in the z-axis direction acting on the tool; Indicates The first tooth The axial cutting force element on the cutting edge element.

[0015] The present invention also provides a real-time cutting force calculation device based on cutting simulation, comprising: A Dexel model building module is used to discretize the tool and the workpiece to be processed using the Tri-Dexel model to obtain the Dexel model of the tool and the Dexel model of the workpiece to be processed; A cutting length and volume calculation module, used for performing Boolean operations on the Dexel model of the tool and the Dexel model of the workpiece to be processed, obtaining the cutting length on each Dexel segment of the workpiece to be processed, and calculating the cutting volume of the tool position point of the tool based on the cutting length on all Dexel segments of the workpiece to be processed; A cutting edge element division and hysteresis angle calculation module, for obtaining an axial cutting depth and a radial cutting depth based on the cutting volume of the tool position point, dividing each tooth of the tool into M cutting edge elements along the tool axis direction, and calculating a hysteresis angle of the tool at an axial cutting depth h based on the cutting edge helix angle and tool radius of the tool; A radial contact angle calculation module is used to calculate the radial contact angle at each cutting edge element on each tooth based on the cutting pitch angle between adjacent cutting edge elements on each tooth, the angular displacement at the end point of the first cutting edge element, and the hysteresis angle of the tool at the axial cutting depth h; A cutting force element calculation module is used to calculate the cutting thickness of each cutting edge element on the workpiece based on the radial contact angle at each cutting edge element and the feed per tooth of the tool; and to calculate the tangential cutting force element, radial cutting force element and axial cutting force element acting on the cutting edge element based on the cutting thickness of the cutting edge element on the workpiece, the tangential plowing force coefficient, the radial plowing force coefficient, the axial plowing force coefficient and the unit step function using the instantaneous rigid force formula; A coordinate conversion module is used to convert the tangential cutting force element, radial cutting force element and axial cutting force element on each cutting edge element to a spatial coordinate system to obtain the cutting force component of each cutting edge element in the x-axis direction, the cutting force component of the y-axis direction and the cutting force component of the z-axis direction; The tool instantaneous cutting force calculation module is used to integrate the cutting force component in the x-axis direction / the cutting force component in the y-axis direction / the cutting force component in the z-axis direction of each cutting edge microelement on all the teeth of the tool to obtain the instantaneous cutting force in the x-axis direction / the instantaneous cutting force in the y-axis direction / the instantaneous cutting force in the z-axis direction acting on the tool.

[0016] The real-time cutting force calculation method based on cutting simulation provided in the present application uses Tri-Dexel to discretize the tool and the workpiece to be processed, and calculates the cutting length and cutting volume of the tool on each Dexel segment of the workpiece to be processed by performing Boolean operations on the Dexel model of the tool and the Dexel model of the workpiece to be processed. The Tri-Dexel method can not only obtain the Dexel data information of the tool and the workpiece to be processed along the three directions of the x, y and z axes, but also the obtained Dexel model has higher fidelity, reduces the amount of data, can perform Boolean operations more effectively, and improves the computational efficiency and robustness; after obtaining the axial cutting depth and radial cutting depth based on the cutting volume, each tooth on the tool is divided into multiple cutting edge elements. Since the angular difference between the cutting edge of the tool and the cutting direction will affect the cutting force, the lag angle of the tool at the axial cutting depth h is calculated based on the cutting edge helix angle and tool radius of the tool; since the radial contact angles on different cutting edge elements will affect the distribution of cutting force, the cutting pitch angle The angular displacement and cutting edge geometry provide detailed information on the cutting edge. Therefore, the radial contact angle at each cutting edge element on the tooth is calculated by the cutting pitch angle between adjacent cutting edge elements on each tooth, the angular displacement at the endpoint of the first cutting edge element, and the lag angle of the tool at the axial cutting depth h, which can help calculate the cutting force on the entire tool. Then, based on the radial contact angle at each cutting edge element and the feed per tooth of the tool, the cutting thickness of the cutting edge element on the workpiece to be machined can be calculated, and then the tangential, radial and axial cutting force elements of the cutting edge element can be calculated according to the instantaneous rigid force formula. Finally, the tangential, radial and axial cutting force elements of each cutting edge element are converted to the spatial coordinate system to obtain the cutting force component of each cutting edge element in the spatial coordinate system. By accumulating the cutting force components of all cutting edge elements, the instantaneous cutting force acting on the entire tool is obtained. There is no need to obtain cutting force data through a large number of cutting experiments, and the calculated cutting force has high accuracy, thereby enabling precise machining of the workpiece. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein: Figure 1 Schematic diagram of surface reconstruction of the Tri-Dexel model provided in this application; wherein, Figure 1 (a) is a schematic diagram of the workpiece bounding box. Figure 1 (b) is a schematic diagram of the remaining workpiece mesh model. Figure 1 (c) is a schematic diagram of the workpiece mesh model; Figure 2 A flow chart of a real-time cutting force calculation method based on cutting simulation provided in this application; Figure 3 A schematic diagram of the Dexel position relationship between the tool provided in this application and the workpiece to be processed; wherein, Figure 3 (a) is a schematic diagram of the initial Dexel position relationship between the tool and the workpiece to be processed. Figure 3 (b) is a schematic diagram of the Dexel position relationship between the tool and the workpiece to be processed during the cutting process; Figure 4 Schematic diagram of the cutting force simulation interface provided for this application; Figure 5 Schematic diagram of the blank model provided for this application; Figure 6 A schematic diagram of the real-time cutting force interface during the simulation process provided for this application; Figure 7 A schematic diagram of a tool cutting a blank during the simulation process provided in this application; Figure 8 Schematic diagram of cutting force simulation results provided for this application; Fig. 9 A schematic diagram of the predicted results of cutting using the cutting force calculated by the method provided in this application; Fig.10 A schematic diagram of cutting force for cutting using the cutting force calculated by the method provided in the present application; Fig.11 For Fig.10 The schematic diagram of cutting force after drift compensation is shown; Fig.12 A schematic diagram of the structure of a real-time cutting force calculation device based on cutting simulation provided in this application. DETAILED DESCRIPTION

[0018] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0019] In the CNC cutting simulation system, the geometric modeling of the workpiece and the tool determines the accuracy and computational efficiency of the simulation. Although the boundary representation method can accurately represent the geometric model, it is difficult to apply it to real-time cutting simulation because the Boolean operation calculation is too complicated. Among the many entity discrete modeling methods, the Boolean operations of voxel and octree modeling methods are complex and consume a lot of memory. The Z-buffer and Dexel modeling methods cannot change the viewing angle and can only contain unidirectional surface information of the three-dimensional model. Since the Tri-Dexel model not only has the high efficiency of Dexel Boolean operations, but also can represent the Dexel data of the tool or workpiece in the x, y, and z directions, the Dexel data in each direction contains several fragments, each fragment has two nodes, and the nodes store the basic properties of the model surface, such as depth, color, and normal. Depth information can be used to perform fast Boolean operations, and normal and color information can be used to reconstruct and render the surface of the geometric body; therefore, this application performs cutting simulation based on the Tri-Dexel model, and calculates real-time cutting force based on the cutting simulation process; When constructing Tri-Dexel data, a large number of intersection operations are required between rays and geometric bodies. The input is often a mesh model containing a large number of triangles, which greatly increases the difficulty of constructing the Tri-Dexel model. Therefore, the embodiment of the present application adopts a depth peeling algorithm to obtain the geometric surface information of the model at different depth levels. In graphics, the depth peeling algorithm is often used for order-independent semi-transparent object rendering. The basic idea is to render the object multiple times in the order from near to far in the observation direction. Each time a layer is peeled off, the object is rendered once until there is no object position to be rendered. The embodiment of the present application peels the image four times, extracts the Tri-Dexel fragment data in every two layers, and finally completes the construction of the Tri-Dexel model, making full use of the depth cache in the GPU, thereby achieving hundreds of thousands of intersection operations at the millisecond level, greatly improving the real-time performance of cutting simulation.

[0020] Furthermore, in the prior art, when using the Tri-Dexel model for cutting simulation, the constructed Tri-Dexel model is often converted into a voxel model to display the remaining workpiece after cutting in the form of voxels. However, this method is difficult to obtain a smooth geometric surface. Therefore, the embodiment of the present application uses the Marching Cubes method to reconstruct the surface mesh of the Cube in the Tri-Dexel model of the workpiece to be processed, such as Figure 1 The figure shows a schematic diagram of surface reconstruction of the Tri-Dexel model provided in this application; wherein, Figure 1 (a) is a schematic diagram of the workpiece bounding box obtained based on the Tri-Dexel data structure. Figure 1(b) is a schematic diagram of the remaining workpiece mesh model when the workpiece is processed. Figure 1 (c) in the figure is a schematic diagram of the workpiece mesh model; this application uses a depth peeling algorithm to construct the structure of Tri-Dexel data, and then uses the Marching Cubes method to reconstruct the surface mesh of the Tri-Dexel model of the workpiece to be processed, thereby realizing cutting simulation, making full use of the parallel performance of the GPU, and implementing the Tri-Dexel surface reconstruction algorithm in the GPU's geometry shader, thereby meeting the real-time requirements of cutting simulation.

[0021] See also Figure 2 , Figure 2 A flow chart of a real-time cutting force calculation method based on cutting simulation provided in this application, the method specifically includes: S10: discretizing the tool and the workpiece to be processed by using the Tri-Dexel model to obtain a Dexel model of the tool and a Dexel model of the workpiece to be processed; Specifically, the Dexel model of the tool includes an x-axis unidirectional Dexel model, a y-axis unidirectional Dexel model, and a z-axis unidirectional Dexel model of the tool; the Dexel model of the workpiece to be processed includes an x-axis unidirectional Dexel model, a y-axis unidirectional Dexel model, and a z-axis unidirectional Dexel model of the workpiece to be processed; S20: performing Boolean operation on the Dexel model of the tool and the Dexel model of the workpiece to be processed to obtain the cutting length of each Dexel segment of the workpiece to be processed, and calculating the cutting volume of the tool position point of the tool based on the cutting length of all Dexel segments of the workpiece to be processed; S30: obtaining the axial cutting depth and the radial cutting depth based on the cutting volume of the tool position point, dividing each tool tooth into M cutting edge micro-elements along the tool axis direction, and calculating the hysteresis angle of the tool at the axial cutting depth h based on the cutting edge helix angle and tool radius of the tool; Since the number of cutting edges involved in the milling process is related to the axial cutting depth and the radial cutting depth, in order to obtain the cutting force under different cutting parameters, it is necessary to analyze the changes in cutting force caused by different parameters. Specifically, the center of the circle at the bottom of the tool is taken as the coordinate origin, the axis direction is the z-axis, the line connecting the center of the circle and the first cutting edge of the tool is the x-axis, and the direction perpendicular to the x-axis and the z-axis is the y-axis, and a spatial coordinate system is established; Assume that the number of teeth on the cutting edge of the cylindrical spiral force milling cutter is , cutting edge helix angle is , tool radius is , axial cutting depth is , radial cutting depth is In order to calculate the overall cutting force, the residual cutting cutting edge is divided into M cutting edge micro-elements along the milling cutter axis (z axis). Due to the existence of the cutting edge helix angle, the point on the cutting edge will lag behind the tool end point. Therefore, the tool has a certain cutting depth in the axial direction. The calculation formula of the lag angle at is: , in, Indicates the axial cutting depth of the tool The hysteresis angle at Indicates cutting depth; Indicates the helix angle of the cutting edge of the tool; Indicates the tool radius.

[0022] S40: Calculate the radial contact angle at each cutting edge element on the tooth based on the cutting pitch angle between adjacent cutting edge elements on each tooth, the angular displacement at the end point of the first cutting edge element, and the hysteresis angle of the tool at the axial cutting depth h; Specifically, if the teeth on the milling cutter are evenly distributed, the cutting pitch angle between adjacent cutting edge elements is , Indicates the number of teeth; Furthermore, the calculation formula of the radial contact angle at each cutting edge microelement on the cutter tooth is: , in, Indicates The first tooth Radial contact angle at each cutting edge microelement; represents the angular displacement at the end point of the first cutting edge microelement; Indicates the cutting pitch angle between connected cutting edges; Indicates the helix angle of the cutting edge of the tool; Indicates the tool radius; Indicates the thickness of the cutting edge microelement; Indicates the number of teeth; S50: based on the radial contact angle at each cutting edge microelement and the feed per tooth of the tool, the cutting thickness of the cutting edge microelement on the workpiece to be processed is calculated; based on the cutting thickness of the cutting edge microelement on the workpiece, the tangential plowing force coefficient, the radial plowing force coefficient, the axial plowing force coefficient and the unit step function, the tangential cutting force microelement, the radial cutting force microelement and the axial cutting force microelement acting on the cutting edge microelement are calculated using the instantaneous rigid force formula; Specifically, since the cutting thickness is a function of the tooth angle, it will change and vary with the angular position of the cutting edge. Therefore, in some embodiments of the present application, the calculation formula for the cutting thickness of the cutting edge microelement on the workpiece to be processed is: , in, Indicates The first tooth The cutting thickness of each cutting edge element on the workpiece to be processed; Indicates the feed per tooth of the tool; Indicates The first tooth Radial contact angle at each cutting edge microelement; Furthermore, according to the basic formula of instantaneous rigid force, the calculation formula of the tangential cutting force element on the cutting edge element is: , in, Indicates The first tooth The tangential cutting force element on the cutting edge element; represents the unit step function; represents the tangential shear force coefficient; represents the tangential plowing force coefficient; The calculation formula of the radial cutting force element on the cutting edge element is: , in, Indicates The first tooth Radial cutting force element on each cutting edge element; represents the radial shear coefficient; represents the radial plowing force coefficient; The calculation formula of the axial cutting force element on the cutting edge element is: , in, Indicates The first tooth The axial cutting force element on each cutting edge element; represents the axial shear coefficient; represents the axial plowing force coefficient; Specifically, the unit step function is used to indicate whether the current cutting edge element participates in cutting, which is specifically expressed as: , in, Indicates the tool cutting angle; Indicates the tool cutting angle; For reverse milling, the calculation formula for the cutting angle and cutting angle is: , For down milling, the calculation formula for the cut-in angle and cut-out angle is: .

[0023] S60: converting the tangential cutting force element, radial cutting force element and axial cutting force element on each cutting edge element to a spatial coordinate system to obtain the cutting force component in the x-axis direction, the cutting force component in the y-axis direction and the cutting force component in the z-axis direction of each cutting edge element; By converting the tangential cutting force microelement, radial cutting force microelement and axial cutting force microelement into the space coordinate system established according to the tool, the cutting force components acting in the space coordinate system can be obtained; Specifically, the cutting force component of the cutting edge microelement in the x-axis direction is expressed as: , in, Indicates The first tooth The cutting force component of each cutting edge element in the x-axis direction; Indicates The first tooth The tangential cutting force element on the cutting edge element; Indicates The first tooth Radial contact angle at each cutting edge microelement; Indicates The first tooth Radial cutting force element on each cutting edge element; The cutting force component of the cutting edge microelement in the y-axis direction is expressed as: , in, Indicates The first tooth The cutting force component of each cutting edge element in the y-axis direction; The cutting force component of the cutting edge microelement in the z-axis direction is expressed as: , in, Indicates The first tooth The cutting force component of each cutting edge element in the z-axis direction; Indicates The first tooth The axial cutting force element on the cutting edge element.

[0024] S70: Integrate the cutting force component in the x-axis direction / the cutting force component in the y-axis direction / the cutting force component in the z-axis direction of each cutting edge microelement on all teeth of the tool to obtain the instantaneous cutting force in the x-axis direction / the instantaneous cutting force in the y-axis direction / the instantaneous cutting force in the z-axis direction acting on the tool; By summing up the cutting force elements on all cutting edge elements on each tooth of the tool along the axial integration, the instantaneous cutting force acting on the entire tool along the x-axis, y-axis and z-axis directions can be obtained; Specifically, the calculation formula of the instantaneous cutting force in the x-axis direction acting on the tool is: , in, It represents the instantaneous cutting force in the x-axis direction acting on the tool; Indicates the number of teeth; Indicates The first tooth The tangential cutting force element on the cutting edge element; No. The first tooth Radial contact angle at each cutting edge microelement; Indicates The first tooth Radial cutting force element on each cutting edge element; The calculation formula of the instantaneous cutting force in the y-axis direction acting on the tool is: , in, It represents the instantaneous cutting force in the y-axis direction acting on the tool; The calculation formula for the instantaneous cutting force in the z-axis direction acting on the tool is: , in, It represents the instantaneous cutting force in the z-axis direction acting on the tool; Indicates The first tooth The axial cutting force element on the cutting edge element.

[0025] The real-time cutting force calculation method based on cutting simulation provided in the present application divides each tooth on the tool into multiple cutting edge elements. Since the angular difference between the cutting edge of the tool and the cutting direction will affect the cutting force, the lag angle of the tool at the axial cutting depth h is calculated based on the cutting edge helix angle and tool radius of the tool; since the radial contact angles on different cutting edge elements will affect the distribution of cutting force, and the cutting pitch angle and angular displacement provide detailed information on the geometric characteristics of the cutting edge, the radial contact angle at each cutting edge element on the tooth is calculated through the cutting pitch angle between adjacent cutting edge elements on each tooth, the angular displacement at the endpoint of the first cutting edge element, and the lag angle of the tool at the axial cutting depth h, which can help calculate the cutting force on the entire tool; then, based on the radial contact angle at each cutting edge element and the feed rate per tooth of the tool, the cutting force of the cutting edge element on the workpiece to be processed can be calculated. Thickness, and then the tangential, radial and axial cutting force elements of the cutting edge element can be calculated according to the instantaneous rigid force formula. Finally, the tangential, radial and axial cutting force elements of each cutting edge element are converted to the spatial coordinate system, and the cutting force components of each cutting edge element in the spatial coordinate system can be obtained. By accumulating the cutting force components of all cutting edge elements, the instantaneous cutting force acting on the entire tool can be obtained. The present application performs local analysis on each cutting edge element, calculates the cutting force of each cutting edge element during the cutting process, and accumulates the cutting forces of all cutting edge elements. The cutting force of the tool is directly calculated based on the processing parameters during the cutting process. Not only can the cutting force be calculated in real time during the cutting process, there is no need to obtain cutting force data through a large number of cutting experiments, and the calculated cutting force has high accuracy. The cutting parameters are optimized based on the calculated cutting force, thereby achieving precise processing of the workpiece.

[0026] In some embodiments of the present application, step S20 specifically includes: Boolean operations are performed on the x-axis unidirectional Dexel model of the tool and the x-axis unidirectional Dexel model of the workpiece to be processed to obtain the cutting length of each Dexel segment in the x-axis direction of the workpiece to be processed; the cutting volume of the workpiece to be processed under the x-axis perspective is calculated based on the cutting lengths of all Dexel segments in the x-axis direction of the workpiece to be processed; Perform Boolean operations on the y-axis unidirectional Dexel model of the tool and the y-axis unidirectional Dexel model of the workpiece to be processed to obtain the cutting length of each Dexel segment in the y-axis direction of the workpiece to be processed; calculate the cutting volume of the workpiece to be processed from the y-axis perspective based on the cutting lengths of all Dexel segments in the y-axis direction of the workpiece to be processed; Boolean operations are performed on the z-axis unidirectional Dexel model of the tool and the z-axis unidirectional Dexel model of the workpiece to be processed to obtain the cutting length of each Dexel segment in the z-axis direction of the workpiece to be processed; the cutting volume of the workpiece to be processed under the z-axis perspective is calculated based on the cutting lengths of all Dexel segments in the z-axis direction of the workpiece to be processed; The cutting volume of the tool position point of the tool is obtained based on the average of the cutting volume of the workpiece to be processed under the x-axis perspective, the cutting volume under the y-axis perspective, and the cutting volume under the z-axis perspective.

[0027] Specifically, when the Tri-Dexel model of the tool and the Tri-Dexel model of the workpiece to be processed are subjected to Boolean operations during the NC simulation process, there are six cases of their relative positions: The workpiece to be processed does not intersect with the tool, and no cutting is performed. The Dexel segment (DexelSegment) of the workpiece to be processed remains in its original state; As in the first case, the workpiece to be processed is not cut, and the DexelSegment of the workpiece to be processed remains in its original state; The upper end point of the workpiece to be processed is smaller than the lower end point of the tool, and the portion from the upper end point of the workpiece to be processed to the lower end point of the tool is cut; The lower end point of the workpiece to be processed is larger than the upper end point of the tool, and the portion from the lower end point of the workpiece to be processed to the upper end point of the tool is cut; The upper and lower endpoints of the workpiece to be processed are between the upper and lower endpoints of the tool, and the workpiece to be processed is completely cut; The upper and lower end points of the tool are between the upper and lower end points of the workpiece to be processed, and the workpiece to be processed is cut into two ends.

[0028] Since the Dexel in each direction of the workpiece and the tool is composed of several DexelSegments parallel to the direction, and each DexelSegment has two endpoints VertexMax and VertexMin, in order to facilitate the expression that each endpoint only contains the Z value and the normal, the upper and lower endpoints of the tool DexelSegment are CMax and CMin, and the upper and lower endpoints of the workpiece DexelSegment are WMax and WMin, respectively. After the interference cutting of each tool and the DexelSegment of the workpiece to be processed, the cutting length of the workpiece to be processed in the corresponding direction is The calculation formula is: , Furthermore, after obtaining the cutting length, the line segment DexelSegment set in Dexel is regarded as a set of rectangular cylinders. In the initial state, the volume of the workpiece to be processed is evenly divided by all DexelSegments, that is, the bottom area of ​​all DexelSegments is equal. The cutting length of each DexelSegment of the workpiece to be processed is obtained from the relative position relationship between the tool and the workpiece DexelSegment. , and the volume of the cut part is equivalent to the sum of the volumes of all DexelSegments cut from the workpiece to be processed, so the calculation formula for the cutting volume V is: , in, Indicates the bottom area of ​​the DexelSegment.

[0029] For example, Figure 3 As shown, the initial Dexel position relationship between the tool and the workpiece to be processed is as follows Figure 3 As shown in (a) in the figure, the Dexel position relationship between the tool and the workpiece to be processed during the cutting process is as follows: Figure 3 As shown in (b) in .

[0030] Furthermore, according to the mechanical method proposed by Budak for rapid calibration of the cutting force coefficient of the milling cutter, the milling experiment was carried out by changing the feed rate under a fixed contact angle and axial cutting depth, and the average cutting force of each tooth cycle was measured. In order to avoid the influence of tool eccentricity during measurement, the total cutting force per spindle revolution was first measured and then divided by the number of teeth. The cutting force coefficient was identified by equating the measured average cutting force to the theoretical average cutting force. Optionally, in some embodiments of the present application, after obtaining the instantaneous x-axis cutting force / y-axis cutting force / z-axis cutting force acting on the tool, the method further includes: The average instantaneous cutting force in the x-axis direction, the average instantaneous cutting force in the y-axis direction and the average instantaneous cutting force in the z-axis direction of the tool are calculated respectively under a plurality of preset feed rates per tooth; Specifically, the calculation formula for the average x-axis instantaneous cutting force of the tool at each preset feed per tooth is: , in, Indicates the feed rate per tooth of the tool Average x-axial instantaneous cutting force under; Indicates the number of teeth; Indicates the axial cutting depth; represents the radial shear coefficient; represents the radial plowing force coefficient; The calculation formula for the average instantaneous cutting force in the y-axis direction of the tool at each preset feed per tooth is: , in, Indicates the feed rate per tooth of the tool Average instantaneous cutting force in the y-axis direction under ; represents the tangential shear force coefficient; represents the tangential plowing force coefficient; The calculation formula for the average instantaneous cutting force in the z-axis direction of the tool at each preset feed per tooth is: , in, Indicates the feed rate per tooth of the tool Average instantaneous cutting force in z-axis direction under ; represents the axial shear coefficient; represents the axial plowing force coefficient; From the above formula, it can be seen that by changing the feed per tooth , calculate the average instantaneous cutting force of the tool corresponding to each tooth feed, and then perform linear regression on these average instantaneous cutting forces of the tool to obtain the cutting force coefficient; The least squares method is used to perform linear fitting on the average x-axis instantaneous cutting force, the average y-axis instantaneous cutting force and the average z-axis instantaneous cutting force under all preset feed rates per tooth to obtain the cutting force coefficient of the tool.

[0031] For example, in a Code 800 CNC machine tool with A swing head and C rotary table, the blank material is high temperature alloy GH4169, the tool is a solid carbide flat bottom milling cutter with a diameter of 10mm, the number of cutting edges is 4, the cutting speed is 70m / min, the feed per tooth is 0.04mm, the cutting depth is 0.10mm, and the cutting width is 10mm. The experimental specimen is a block material; The cutting force measurement equipment is a Kistler rotary dynamometer, the experimental sampling frequency is 10kHz, the data is collected by a Kistler signal acquisition instrument, the spindle speed corresponding to the experiment is 2229r / min, the axial cutting depth is 0.1mm, and the slot milling cutting force experimental results of 0.01mm / z, 0.02mm / z, 0.03mm / z, 0.04mm / z, and 0.05mm / z per tooth feed are collected by the dynamometer equipment. The experimental measurement scheme is shown in Table 1: Table 1 Serial number Feed per tooth / mm Cutting speed / (m / min) <![CDATA[Depth of cut a p / mm]]> 1 0.01 70 0.1 2 0.02 70 0.1 3 0.03 70 0.1 4 0.04 70 0.1 5 0.05 70 0.1 The calculated average instantaneous cutting force of the tool under different feed rates per tooth is shown in Table 2: Table 2 Feed per tooth fz / (mm / r) Average value of force in x direction Fx / N Average value of force in y direction Fy / N Average value of z-direction force Fz / N 0.01 39.34191 -8.31119 -4.26183 0.02 40.02551 -0.23732 -5.93607 0.03 42.8452 -3.22158 -4.12484 0.04 47.45139 -1.4445 -7.17212 0.05 54.02823 -0.39702 -3.94362 The cutting force coefficient obtained by fitting the average instantaneous cutting force of the tool in Table 2 using the least squares method is shown in Table 3: Table 3 Cutting depth (mm) <![CDATA[K tc (N / mm²)]]> <![CDATA[K rc (N / mm²)]]> <![CDATA[K ac (N / mm²)]]> <![CDATA[K te (N / mm)]]> <![CDATA[K rc (N / mm)]]> <![CDATA[K ae (N / mm)]]> 0.1 3679.9 1462.1 60.0 265 55.8 38.5 The following is a specific example to further explain the above-mentioned real-time cutting force calculation method based on cutting simulation: like Figure 4 The figure shows a schematic diagram of the cutting simulation interface provided in this embodiment. By clicking "Select blank file", the blank model STL file is imported and the appropriate cutting accuracy is set, and the blank material is selected. Figure 5 Shown is the blank model selected in this embodiment; Start cutting simulation and click "Show machining parameters", you can see the real-time cutting force calculated based on the real-time cutting force calculation method provided by this application, such as Figure 6 As shown, at the same time, you can see the schematic diagram of the blank model being cut by the tool, such as Figure 7 As shown; After the simulation is finished, click "Export Cutting Force" and select a suitable storage path to store it, and you can obtain the cutting force record of the tool during the cutting simulation process, such as Figure 8 As shown, X, Y, and Z represent the location of the tool. , , are the component forces and resultant forces acting on the tool in the x, y, and z directions, respectively, and V represents the volume of the blank being cut; Next, the accuracy of the above cutting simulation is verified. The cutting of the fine-machined S part is used as the verification object. In the actual processing, a 10mm milling cutter is still used. The cutting parameters of 3mm cutting depth, 0.1mm cutting width, 70m / min cutting speed and 0.04mm feed per tooth are input into the above cutting simulation process. The following results are obtained: Fig. 9 The schematic diagram of the cutting result prediction is shown; Then, the above cutting parameters were used as actual cutting parameters to carry out cutting experiments in block materials, and the following results were obtained: Fig.10 The cutting force diagram is shown in Fig.10 The cutting force after 25 seconds is taken as the analysis object, and the drift compensation is performed to obtain the following Fig.11 Schematic diagram of cutting force shown; The maximum value of the deformation during machining is the force deformation corresponding to the maximum cutting force moment. Therefore, the maximum cutting force is taken as the analysis object to verify the rationality of the cutting modeling and fitting parameters. As can be seen from the figure, The cutting force at the absolute maximum value is -68.23N, which is 19.6% less than the -84.82N obtained by the method provided in this application. The cutting force at the absolute maximum value is -74.17N, which is 20.3% less than the -93.11N obtained by the method provided in this application. The cutting force at the absolute maximum value is 11.58N, which has an error of 0.6% compared with 11.65N obtained using the method provided in this application. The errors in the three directions are basically less than 20%, indicating that the real-time cutting force calculation method based on cutting simulation provided in this application has high accuracy.

[0032] Based on the real-time cutting force calculation method based on cutting simulation provided in the above embodiment, the embodiment of the present application also provides a real-time cutting force calculation device based on cutting simulation, such as Fig.12 As shown, the device specifically includes: A Dexel model building module 10 is used to discretize the tool and the workpiece to be processed by using a Tri-Dexel model to obtain a Dexel model of the tool and a Dexel model of the workpiece to be processed; The cutting length and volume calculation module 20 is used to perform Boolean operations on the Dexel model of the tool and the Dexel model of the workpiece to be processed to obtain the cutting length of each Dexel segment of the workpiece to be processed, and calculate the cutting volume of the tool position point of the tool based on the cutting length of all Dexel segments of the workpiece to be processed; The cutting edge micro-element division and hysteresis angle calculation module 30 is used to obtain the axial cutting depth and the radial cutting depth based on the cutting volume of the tool position point, divide each tool tooth of the tool into M cutting edge micro-elements along the tool axis direction, and calculate the hysteresis angle of the tool at the axial cutting depth h based on the cutting edge helix angle and tool radius of the tool; A radial contact angle calculation module 40 is used to calculate the radial contact angle at each cutting edge element on each tooth based on the cutting pitch angle between adjacent cutting edge elements on each tooth, the angular displacement at the end point of the first cutting edge element, and the hysteresis angle of the tool at the axial cutting depth h; The cutting force microelement calculation module 50 is used to calculate the cutting thickness of the cutting edge microelement on the workpiece based on the radial contact angle at each cutting edge microelement and the feed per tooth of the tool; and calculate the tangential cutting force microelement, radial cutting force microelement and axial cutting force microelement acting on the cutting edge microelement based on the cutting thickness of the cutting edge microelement on the workpiece, the tangential plowing force coefficient, the radial plowing force coefficient, the axial plowing force coefficient and the unit step function by using the instantaneous rigid force formula; A coordinate conversion module 60 is used to convert the tangential cutting force element, radial cutting force element and axial cutting force element on each cutting edge element to a spatial coordinate system to obtain the cutting force component in the x-axis direction, the cutting force component in the y-axis direction and the cutting force component in the z-axis direction of each cutting edge element; The tool instantaneous cutting force calculation module 70 is used to integrate the cutting force components in the x-axis direction / the cutting force components in the y-axis direction / the cutting force components in the z-axis direction of each cutting edge microelement on all the teeth of the tool to obtain the instantaneous cutting force in the x-axis direction / the instantaneous cutting force in the y-axis direction / the instantaneous cutting force in the z-axis direction acting on the tool.

[0033] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0034] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0035] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0036] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0037] Obviously, the above embodiments are merely examples for the purpose of clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the present invention.

Claims

1. A real-time cutting force calculation method based on cutting simulation, characterized in that: include: The tool and the workpiece to be processed are discretized using the Tri-Dexel model to obtain the Dexel model of the tool and the Dexel model of the workpiece to be processed; Performing Boolean operations on the Dexel model of the tool and the Dexel model of the workpiece to be processed to obtain the cutting length on each Dexel segment of the workpiece to be processed, and calculating the cutting volume of the tool position point of the tool based on the cutting lengths on all Dexel segments of the workpiece to be processed; The axial cutting depth and the radial cutting depth are obtained based on the cutting volume of the tool position point of the tool, each tool tooth of the tool is divided into M cutting edge micro-elements along the tool axis direction, and the hysteresis angle of the tool at the axial cutting depth h is calculated based on the cutting edge helix angle and tool radius of the tool; Based on the cutting pitch angle between adjacent cutting edge micro-elements on each tooth, the angular displacement at the end point of the first cutting edge micro-element and the hysteresis angle of the tool at the axial cutting depth h, the radial contact angle at each cutting edge micro-element on the tooth is calculated; Based on the radial contact angle at each cutting edge microelement and the feed per tooth of the tool, the cutting thickness of the cutting edge microelement on the workpiece to be processed is calculated; By using the instantaneous rigid force formula, based on the cutting thickness of the cutting edge microelement on the workpiece, the tangential plowing force coefficient, the radial plowing force coefficient, the axial plowing force coefficient and the unit step function, the tangential cutting force microelement, the radial cutting force microelement and the axial cutting force microelement acting on the cutting edge microelement are calculated; The tangential cutting force element, radial cutting force element and axial cutting force element on each cutting edge element are converted to the spatial coordinate system to obtain the cutting force component in the x-axis direction, the cutting force component in the y-axis direction and the cutting force component in the z-axis direction of each cutting edge element; The cutting force component in the x-axis direction, the cutting force component in the y-axis direction, and the cutting force component in the z-axis direction of each cutting edge microelement on all the teeth of the tool are integrated to obtain the instantaneous cutting force in the x-axis direction, the instantaneous cutting force in the y-axis direction, and the instantaneous cutting force in the z-axis direction acting on the tool.

2. The real-time cutting force calculation method based on cutting simulation according to claim 1 is characterized in that: The Dexel model of the tool includes the x-axis unidirectional Dexel model, the y-axis unidirectional Dexel model and the z-axis unidirectional Dexel model of the tool; the Dexel model of the workpiece to be processed includes the x-axis unidirectional Dexel model, the y-axis unidirectional Dexel model and the z-axis unidirectional Dexel model of the workpiece to be processed.

3. The real-time cutting force calculation method based on cutting simulation according to claim 2 is characterized in that: The Dexel model of the tool and the Dexel model of the workpiece to be processed are subjected to Boolean operation to obtain the cutting length of each Dexel segment of the workpiece to be processed. Based on the cutting length of all Dexel segments of the workpiece to be processed, the cutting volume of the tool position point of the tool is calculated, including: Boolean operations are performed on the x-axis unidirectional Dexel model of the tool and the x-axis unidirectional Dexel model of the workpiece to be processed to obtain the cutting length of each Dexel segment in the x-axis direction of the workpiece to be processed; the cutting volume of the workpiece to be processed under the x-axis perspective is calculated based on the cutting lengths of all Dexel segments in the x-axis direction of the workpiece to be processed; Perform Boolean operations on the y-axis unidirectional Dexel model of the tool and the y-axis unidirectional Dexel model of the workpiece to be processed to obtain the cutting length of each Dexel segment in the y-axis direction of the workpiece to be processed; calculate the cutting volume of the workpiece to be processed from the y-axis perspective based on the cutting lengths of all Dexel segments in the y-axis direction of the workpiece to be processed; Boolean operations are performed on the z-axis unidirectional Dexel model of the tool and the z-axis unidirectional Dexel model of the workpiece to be processed to obtain the cutting length of each Dexel segment in the z-axis direction of the workpiece to be processed; the cutting volume of the workpiece to be processed under the z-axis perspective is calculated based on the cutting lengths of all Dexel segments in the z-axis direction of the workpiece to be processed; The cutting volume of the tool position point of the tool is obtained based on the average of the cutting volume of the workpiece to be processed under the x-axis perspective, the cutting volume under the y-axis perspective, and the cutting volume under the z-axis perspective.

4. The real-time cutting force calculation method based on cutting simulation according to claim 1 is characterized in that: After obtaining the instantaneous cutting force in the x-axis direction, the instantaneous cutting force in the y-axis direction, and the instantaneous cutting force in the z-axis direction acting on the tool, it also includes: The average instantaneous cutting force in the x-axis direction, the average instantaneous cutting force in the y-axis direction and the average instantaneous cutting force in the z-axis direction of the tool are calculated respectively under a plurality of preset feed rates per tooth; The least squares method is used to perform linear fitting on the average x-axis instantaneous cutting force, the average y-axis instantaneous cutting force and the average z-axis instantaneous cutting force under all preset feed rates per tooth to obtain the cutting force coefficient of the tool.

5. The real-time cutting force calculation method based on cutting simulation according to claim 1 is characterized in that: The calculation formula of the tool lag angle at the axial cutting depth h is: ， in, It represents the lag angle of the tool at the axial cutting depth h; Indicates cutting depth; Indicates the helix angle of the cutting edge of the tool; Indicates the tool radius.

6. The real-time cutting force calculation method based on cutting simulation according to claim 1 is characterized in that: The calculation formula of the radial contact angle at each cutting edge microelement on the cutter tooth is: ， ， in, Indicates The first tooth Radial contact angle at each cutting edge microelement; represents the angular displacement at the end point of the first cutting edge microelement; Indicates the cutting pitch angle between connected cutting edges; Indicates the helix angle of the cutting edge of the tool; Indicates the tool radius; Indicates the thickness of the cutting edge microelement; Indicates the number of teeth.

7. The real-time cutting force calculation method based on cutting simulation according to claim 1 is characterized in that: The calculation formula for the cutting thickness of the cutting edge microelement on the workpiece to be processed is: ， in, Indicates The first tooth The cutting thickness of each cutting edge element on the workpiece to be processed; Indicates the feed per tooth of the tool; Indicates The first tooth Radial contact angle at each cutting edge microelement; The calculation formula of the tangential cutting force element on the cutting edge element is: ， ， in, Indicates The first tooth The tangential cutting force element on the cutting edge element; represents the unit step function; Indicates the tool cutting angle; Indicates the tool cutting angle; represents the tangential shear force coefficient; represents the tangential plowing force coefficient; The calculation formula of the radial cutting force element on the cutting edge element is: ， in, Indicates The first tooth Radial cutting force element on each cutting edge element; represents the radial shear coefficient; represents the radial plowing force coefficient; The calculation formula of the axial cutting force element on the cutting edge element is: ， in, Indicates The first tooth The axial cutting force element on each cutting edge element; represents the axial shear coefficient; Represents the axial plowing force coefficient.

8. The real-time cutting force calculation method based on cutting simulation according to claim 1 is characterized in that: The cutting force component of the cutting edge microelement in the x-axis direction is expressed as: ， in, Indicates The first tooth The cutting force component of the cutting edge microelement in the x-axis direction; Indicates The first tooth The tangential cutting force element on the cutting edge element; Indicates The first tooth Radial contact angle at each cutting edge microelement; Indicates The first tooth Radial cutting force element on each cutting edge element; The target radial cutting force element on the cutting edge element is expressed as: ， in, Indicates The first tooth The cutting force component of the cutting edge microelement in the y-axis direction; The target axial cutting force element on the cutting edge element is expressed as: ， in, Indicates The first tooth The cutting force component of the cutting edge microelement in the z-axis direction; Indicates The first tooth The axial cutting force element on the cutting edge element.

9. The real-time cutting force calculation method based on cutting simulation according to claim 1 is characterized in that: The calculation formula of the instantaneous cutting force in the x-axis direction acting on the tool is: ， in, It represents the instantaneous cutting force in the x-axis direction acting on the tool; Indicates the number of teeth; Indicates The first tooth The tangential cutting force element on the cutting edge element; No. The first tooth Radial contact angle at each cutting edge microelement; Indicates The first tooth Radial cutting force element on each cutting edge element; The calculation formula of the instantaneous cutting force in the y-axis direction acting on the tool is: ， in, It represents the instantaneous cutting force in the y-axis direction acting on the tool; The calculation formula for the instantaneous cutting force in the z-axis direction acting on the tool is: ， in, It represents the instantaneous cutting force in the z-axis direction acting on the tool; Indicates The first tooth The axial cutting force element on the cutting edge element.

10. A real-time cutting force calculation device based on cutting simulation, characterized in that: include: A Dexel model building module is used to discretize the tool and the workpiece to be processed using the Tri-Dexel model to obtain the Dexel model of the tool and the Dexel model of the workpiece to be processed; A cutting length and volume calculation module, used for performing Boolean operations on the Dexel model of the tool and the Dexel model of the workpiece to be processed, obtaining the cutting length on each Dexel segment of the workpiece to be processed, and calculating the cutting volume of the tool position point of the tool based on the cutting length on all Dexel segments of the workpiece to be processed; A cutting edge element division and hysteresis angle calculation module, for obtaining an axial cutting depth and a radial cutting depth based on the cutting volume of the tool position point, dividing each tooth of the tool into M cutting edge elements along the tool axis direction, and calculating a hysteresis angle of the tool at an axial cutting depth h based on the cutting edge helix angle and tool radius of the tool; A radial contact angle calculation module is used to calculate the radial contact angle at each cutting edge element on each tooth based on the cutting pitch angle between adjacent cutting edge elements on each tooth, the angular displacement at the end point of the first cutting edge element, and the hysteresis angle of the tool at the axial cutting depth h; A cutting force microelement calculation module is used to calculate the cutting thickness of each cutting edge microelement on the workpiece based on the radial contact angle at each cutting edge microelement and the feed rate per tooth of the tool; By using the instantaneous rigid force formula, based on the cutting thickness of the cutting edge microelement on the workpiece, the tangential plowing force coefficient, the radial plowing force coefficient, the axial plowing force coefficient and the unit step function, the tangential cutting force microelement, the radial cutting force microelement and the axial cutting force microelement acting on the cutting edge microelement are calculated; A coordinate conversion module is used to convert the tangential cutting force element, radial cutting force element and axial cutting force element on each cutting edge element to a spatial coordinate system to obtain the cutting force component of each cutting edge element in the x-axis direction, the cutting force component of the y-axis direction and the cutting force component of the z-axis direction; The tool instantaneous cutting force calculation module is used to integrate the cutting force component in the x-axis direction / the cutting force component in the y-axis direction / the cutting force component in the z-axis direction of each cutting edge microelement on all the teeth of the tool to obtain the instantaneous cutting force in the x-axis direction / the instantaneous cutting force in the y-axis direction / the instantaneous cutting force in the z-axis direction acting on the tool.

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