Method and device for designing a protective cover for a numerically controlled machine tool

Abstract

The application provides a design method and device for a protective cover of a numerical control machine tool, and relates to the technical field of numerical control machine tool structure design and optimization. The method comprises the following steps: constructing a machine tool main body, a protective cover and a screw joint of a numerical control machine tool model; determining a finite element model of the protective cover without internal rib plates based on an effective contact area between the screw joint and the protective cover and mechanical performance parameters of the screw joint; analyzing the finite element model based on a plurality of preset working conditions to determine an analysis result, wherein the analysis result comprises deformation parameters and dynamic characteristic parameters of the protective cover under various working conditions; and based on the analysis result, performing collaborative optimization on the rib plate layout at the screw installation position and the support position between the screw joint and the protective cover and the rib plate layout inside the protective cover to complete the design of the protective cover. The application can guarantee the accuracy maintenance and reliability of the numerical control machine tool during service.

Description

Technical Field

[0001] This invention relates to the field of CNC machine tool structure design and optimization technology, and in particular to a design method and device for a protective cover for CNC machine tools. Background Technology

[0002] The CNC machine tool protective cover is a core component for the overall protection of the machine tool. It is constructed from cold-rolled steel plates welded / spliced, with reinforcing ribs added to the inner wall of the steel plate. It is fixed to the machine bed with screws and primarily used to enclose the machining area of ​​the machine tool, achieving safety protection, sound insulation and noise reduction, and a unified appearance. The dynamic stiffness, vibration characteristics, and reliability of the connection points of the CNC machine tool protective cover affect the overall accuracy and operational stability of the CNC machine tool.

[0003] As CNC machine tools develop towards high speed, high precision, and heavy load, the design requirements for protective covers are becoming increasingly stringent. In addition to basic requirements for appearance protection, dust and water resistance, higher requirements are also being placed on the design of the protective cover's structural rigidity, vibration resistance, low noise, and reliability of connections.

[0004] The cutting impact and vibration loads borne by the protective cover need to be transferred to the machine bed and foundation through the stiffeners and screw joints. However, existing design methods usually design the width and stiffener layout of the internal stiffeners, screw connection positions and machine bed support positions based on experience. Moreover, the design process mainly focuses on how to improve and optimize the arrangement of the stiffeners, without fully considering the load transfer path of the protective cover. This makes it difficult to achieve the optimal structural performance of the structural design scheme, and problems such as local stress concentration, loose connections and vibration amplification are likely to occur. The performance of CNC machine tools needs to be improved. Summary of the Invention

[0005] This invention provides a design method and device for a protective cover for CNC machine tools, which solves the problems of existing technologies that make it difficult to achieve optimal structural performance, and that are prone to local stress concentration, loose connections, and vibration amplification, thus hindering the improvement of CNC machine tool performance.

[0006] This invention provides a design method for a protective cover for CNC machine tools, comprising: The machine tool body, protective cover, and screw joints are used to construct the CNC machine tool model; Based on the effective contact area between the screw joint and the protective cover, and the mechanical performance parameters of the screw joint, the finite element model of the protective cover in the case of no internal stiffeners is determined. The finite element model is analyzed based on multiple preset working conditions to determine the analysis results, which include the deformation parameters and dynamic characteristic parameters of the protective cover under various working conditions. Based on the analysis results, the screw installation position between the screw joint and the protective cover, the rib layout at the support position, and the rib layout inside the protective cover are optimized in a coordinated manner to complete the design of the protective cover.

[0007] As one embodiment, determining the finite element model of the protective cover without internal stiffeners based on the effective contact area between the screw joint and the protective cover, and the mechanical property parameters of the screw joint, includes: Based on the effective contact area between the screw joint and the protective cover, the installation position between the protective cover and the machine tool body is determined. Based on the installation location and the mechanical performance parameters, determine the boundary conditions; Based on the boundary conditions, the finite element model of the protective cover is determined when there are no internal stiffeners.

[0008] As an example, based on the analysis results, the coordinated optimization of the screw mounting position between the screw joint and the protective cover, the rib layout at the support position, and the rib layout inside the protective cover includes: Based on the analysis results, the response indicators required for collaborative optimization are determined, and based on the response indicators, the constraints required for collaborative optimization are determined. Based on the constraints and the preset objective function, the screw installation position between the screw joint and the protective cover, the rib layout at the support position, and the rib layout inside the protective cover are optimized collaboratively.

[0009] As an example, the coordinated optimization of the screw mounting position between the screw joint and the protective cover, the rib layout at the support position, and the rib layout inside the protective cover, based on the constraints and a preset objective function, includes: The optimization variables for the rib layout at the screw installation position and the support position are set as the unit density of the screw joint and the support component corresponding to the support position, respectively. The rib layout at the screw installation position and the support position is optimized based on the unit density to satisfy the constraints and the objective function. The optimization variable for the rib layout inside the protective cover is set as the displacement of the nodes inside the protective cover; The layout of the ribs inside the protective cover is optimized by adjusting the displacement to satisfy the constraints and the objective function.

[0010] As one embodiment, after the coordinated optimization of the screw mounting position between the screw joint and the protective cover, the rib layout at the support position, and the rib layout inside the protective cover, the method further includes: An optimized structural model of the protective cover is determined. If the optimized structural model meets the preset installation and processing conditions, the geometric model of the optimized structural model is reconstructed to obtain the geometric model of the protective cover. The geometric model is subjected to stiffener size optimization and sensitivity analysis. If the sensitivity analysis results meet the sensitivity conditions, the optimized geometric model is used as the target model of the protective cover.

[0011] As one embodiment, the geometric model reconstruction of the optimized structural model to obtain the geometric model of the protective shield includes: Based on the rib layout, number of ribs, rib type, screw mounting hole positions and spacing inside the protective cover, the optimized structural model is geometrically reconstructed and locally adjusted to obtain the geometric model of the protective cover. The local adjustments include adjustments to the fillets and chamfers. The process of optimizing the stiffener dimensions and performing sensitivity analysis on the geometric model includes: Based on the stiffness value and natural frequency under preset working conditions, the optimization objective is determined; Based on the sheet metal bending and welding parameters of the stiffener, the key dimensions of the stiffener are determined to optimize the stiffener size; Sensitivity analysis is performed based on the correspondence between the optimized stiffener dimensions and the optimization target.

[0012] The present invention also provides a design device for a protective cover for a CNC machine tool, comprising: The building module is used to construct the machine tool body, protective cover, and screw joints of the CNC machine tool model; The first determining module is used to determine the finite element model of the protective cover without internal stiffeners based on the effective contact area between the screw joint and the protective cover, and the mechanical performance parameters of the screw joint. The second determining module is used to analyze the finite element model based on multiple preset working conditions and determine the analysis results. The analysis results include the deformation parameters and dynamic characteristic parameters of the protective cover under various working conditions. An optimization module is used to collaboratively optimize the screw installation position between the screw joint and the protective cover, the rib layout at the support position, and the rib layout inside the protective cover based on the analysis results, so as to complete the design of the protective cover.

[0013] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the design method of the CNC machine tool protective cover as described above.

[0014] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the design method of the CNC machine tool protective cover as described above.

[0015] The present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the design method of the CNC machine tool protective cover as described above.

[0016] The present invention provides a design method and apparatus for a CNC machine tool protective cover. The method includes: constructing a machine tool body, a protective cover, and a screw joint in the form of a CNC machine tool model; determining a finite element model of the protective cover without internal stiffeners based on the effective contact area between the screw joint and the protective cover, and the mechanical performance parameters of the screw joint; analyzing the finite element model based on various preset working conditions, and determining the analysis results, including the deformation parameters and dynamic characteristic parameters of the protective cover under various working conditions; and based on the analysis results, co-optimizing the screw installation position between the screw joint and the protective cover, the stiffener layout at the support position, and the stiffener layout inside the protective cover to complete the design of the protective cover. Since the cutting impact and vibration loads borne by the protective cover need to be transmitted to the machine bed and foundation through the stiffeners and screw joints, this invention considers the relationship between the stiffener layout, screw joints, and machine bed in the load transmission path of the protective cover. By determining the effective contact area between the screw joints and the protective cover, and the mechanical performance parameters of the screw joints, a finite element model is determined. The finite element model is analyzed to determine the deformation parameters and dynamic characteristic parameters of the protective cover under various working conditions. Then, the stiffener layout at the screw installation position, the support position, and the stiffener layout inside the protective cover are optimized in a coordinated manner. This solves the problem that the existing technology fails to fully consider the load transmission path of the protective cover, which makes it difficult to achieve the optimal structural performance of the structural design scheme, and easily leads to local stress concentration, loose connection, and vibration amplification. This ensures the accuracy and reliability of the CNC machine tool during service. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is one of the flowcharts illustrating the design method of the CNC machine tool protective cover provided by the present invention.

[0019] Figure 2 This is a structural schematic diagram of the CNC machine tool provided by the present invention.

[0020] Figure 3 This is a schematic diagram of the structure of the machine tool body provided by the present invention.

[0021] Figure 4 This is a schematic cross-sectional view of the specimen model provided by the present invention.

[0022] Figure 5 This is a schematic diagram illustrating the process of determining the geometric parameters of the support position provided by the present invention.

[0023] Figure 6 This is a schematic diagram of the parameter identification process for screw joints provided by the present invention.

[0024] Figure 7 This is one of the structural schematic diagrams of the protective cover provided by the present invention.

[0025] Figure 8 This is the second schematic diagram of the structure of the protective cover provided by the present invention.

[0026] Figure 9 This is a schematic diagram of the collaborative optimization process provided by the present invention.

[0027] Figure 10 This is a schematic diagram of the morphological optimization method of rib extension and the rib plate combination form provided by the present invention.

[0028] Figure 11 This is a schematic diagram of the cross-sectional structure of the stiffener plate provided by the present invention.

[0029] Figure 12 This is the second flowchart illustrating the design method of the CNC machine tool protective cover provided by the present invention.

[0030] Figure 13 This is a schematic diagram of the design device for the CNC machine tool protective cover provided by the present invention.

[0031] Figure 14 This is a schematic diagram of the structure of the electronic device provided by the present invention.

[0032] Reference numerals: 1-Machine tool body, 101-Screw joint area, 102-Support position, 2-Protective cover, 201-Top cover of the protective cover, 202-Main body of the protective cover, 203-Front door, 204-Front door glass, 205-Right door, 206-Rear door, 207-Lower cover, 208-Left door, 209-Left door glass, 210-Electrical maintenance door, 211-Electrical maintenance door glass, 212-Right wiring trough, 213-Left wiring trough, 3-Test piece model, 301-Screw, 302-Washer, 303-Sheet metal layer, 304-Damping layer, 305-Structural component. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0034] Figure 1 This is one of the flowcharts illustrating the design method of the CNC machine tool protective cover provided by the present invention, such as... Figure 1 As shown, the present invention provides a design method for a protective cover for a CNC machine tool, which is applied in the design stage of a CNC machine tool. The method includes steps S110-S140.

[0035] Step S110: Construct the machine tool body, protective cover, and screw joint of the CNC machine tool model.

[0036] like Figures 2-4 As shown, the present invention constructs a three-dimensional geometric model of the CNC machine tool body 1, protective cover 2, and test piece model 3 in geometric modeling software. The test piece model 3 includes screws 301, washers 302, sheet metal layer 303, damping layer 304, and structural components 305. The damping layer 304 includes, but is not limited to, rubber pads, manganese copper alloy, ceramic foam, and composite constraint damping layers.

[0037] Structural component 305 is a partial structure at the support position 102 of the machine tool body 1, and sheet metal layer 303 is a partial structure of protective cover 2. The machine tool body 1 is provided with a screw joint area 101. At the screw joint area 101, screw 301 passes through washer 302 and sheet metal layer 303 from top to bottom, and is tightened into the damping layer 304 and structural component 305 below. The washer 302 disperses the locking pressure of screw 301, and the damping layer 304 plays a role in vibration reduction and buffering, so that the protective cover 2 can be installed firmly and reliably on the machine tool body 1.

[0038] The protective cover 2 is installed on the machine tool body 1 and requires multiple screws 301. Each screw 301 is fixed according to the test piece model 3. The screw joint includes the screw 301, the screw head joint formed by the screw 301 and the washer 302, and the threaded joint.

[0039] Step S120: Based on the effective contact area between the screw joint and the protective cover, and the mechanical performance parameters of the screw joint, determine the finite element model of the protective cover in the case of no internal stiffeners.

[0040] The effective contact area refers to the area around the screw, screw head joint, and threaded joint where the contact pressure is non-zero. The contact pressure of the screw joint is obtained by analyzing the two-plane joint under preload through nonlinear statics.

[0041] The effective contact area of ​​the screw joint can be obtained through nonlinear static analysis of the specimen model, thereby determining the geometric parameters of the support position. Specifically, the friction coefficient and locking torque in the nonlinear static analysis model are obtained based on experiments and actual working conditions, and the width of the support position is not less than the width of the effective contact area.

[0042] like Figure 5 As shown, a nonlinear static analysis is performed. Given the screw specifications, machining accuracy between mating surfaces, and tightening torque of the screw connection, the effective contact range of the screw joint is obtained, and the equivalent mechanical performance parameters of the screw joint are further determined to determine the width of the protective cover support position.

[0043] Mechanical performance parameters can be obtained based on techniques such as modal testing, and are used to match the mode shapes and natural frequencies of modal testing. Modal testing includes, but is not limited to, free modes and supported modes.

[0044] like Figure 6 As shown, numerical modal analysis and experimental modal analysis are performed on the actual structure of the screw joint. The results of the two analyses are then compared in terms of modal shape matching and natural frequencies, and a given threshold is set for comparison. If the comparison results do not meet the threshold requirements, the joint surface parameter values ​​are corrected, and the corrected parameters are re-input into the numerical modal analysis to form an iterative optimization closed loop. If the threshold requirements are met, the final parameter identification results are directly output.

[0045] The equivalent methods for screw joints include, but are not limited to, spring element equivalence, beam element equivalence, shell element equivalence, linear virtual material equivalence, and nonlinear virtual material equivalence; the equivalent design parameters of the spring element include, but are not limited to, tangential stiffness, normal stiffness, tangential damping, and normal damping; the mechanical parameters of the virtual material element include elastic modulus, tangential modulus, Poisson's ratio, etc., in order to determine the contact optimization area between the main body of the screw joint plane and to optimize the design of the screw installation location.

[0046] Since the cutting impact and vibration loads borne by the protective cover need to be transmitted to the machine bed and foundation through the ribs and screw joints, based on the effective contact area between the screw joints and the protective cover, and the mechanical performance parameters of the screw joints, the finite element model of the protective cover without internal ribs is determined. In subsequent steps, the screw installation positions between the screw joints and the protective cover, the rib layout at the support positions, and the rib layout inside the protective cover are optimized in a coordinated manner. This can achieve a high rigidity and low vibration design for the protective cover, ensuring the accuracy and reliability of the CNC machine tool during service.

[0047] Step S130: Analyze the finite element model based on multiple preset working conditions and determine the analysis results. The analysis results include the deformation parameters and dynamic characteristic parameters of the protective cover under various working conditions.

[0048] Taking into account the pose changes of the protective cover under various working conditions, the finite element model is analyzed based on various working conditions to obtain analysis results. Subsequent collaborative optimization using the analysis results can make the optimized protective cover more closely match the pose changes of the protective cover during the use stage, eliminating the need for further optimization during the use stage. This can reduce R&D costs, reduce version iterations, and enable CNC machine tools to achieve higher machining accuracy.

[0049] Step S140: Based on the analysis results, the screw installation position between the screw joint and the protective cover, the rib layout at the support position, and the rib layout inside the protective cover are optimized collaboratively to complete the design of the protective cover. Here, the support position refers to the support position of the machine tool body.

[0050] The layout of the ribs at the screw installation location and the support location can be combined into topology optimization, and the layout of the ribs inside the protective cover can be understood as morphology optimization. In the preferred embodiment, the topology optimization and morphology optimization design analysis processes can be defined separately, the optimization design areas of the protective cover and the screw joint can be defined separately, and the morphology optimization reinforcing rib parameters can be set. Furthermore, the weights of the topology optimization and morphology optimization working conditions can be determined separately, the optimization algorithm can be defined, and the collaborative topology optimization design of the ribs inside the machine protective cover, the rib layout at the support location, and the screw installation location can be performed.

[0051] In current machine tool protective cover designs, the protective cover, screw connections, and bed support layout are generally designed separately and independently. The protective cover only considers protection and sealing, the screw connections only meet assembly and locking requirements, and the bed support layout only checks the rigidity of the bed body. Furthermore, the protective cover is generally considered to be an external accessory and does not participate in the main load transfer. Existing technologies rarely analyze the load transfer path of the protective cover, screw connection positions, and bed support layout as a coupled system. This results in individual parts passing simulation, but under actual working conditions, the protective cover is prone to vibration, and stress concentration occurs at the screw connection points. The additional load transferred by the protective cover causes local deformation of the bed, affecting the machine tool accuracy. This invention considers the relationship between the rib layout, screw joints, and machine bed in the load transmission path of the protective cover. By determining the effective contact area between the screw joints and the protective cover, and the mechanical performance parameters of the screw joints, a finite element model is established. This model is then analyzed to determine the deformation and dynamic characteristics of the protective cover under various working conditions. Furthermore, the rib layout at the screw installation positions, support positions, and the internal rib layout of the protective cover is optimized collaboratively. This invention changes the design concept of the protective cover serving only as an external protective cover and the screws only for tightening. By controlling the interface load distribution through screw point positioning, it solves the problems of existing technologies failing to fully consider the load transmission path of the protective cover and the machine bed support layout not matching the load applied to the protective cover. It also eliminates the problems of localized stress concentration, loose connections, and vibration amplification in machine tool protective covers caused by modular independent design, ensuring the accuracy and reliability of CNC machine tools during service.

[0052] As one embodiment, determining the finite element model of the protective cover without internal stiffeners based on the effective contact area between the screw joint and the protective cover, and the mechanical property parameters of the screw joint, includes: Based on the effective contact area between the screw joint and the protective cover, the installation position between the protective cover and the machine tool body is determined. Based on the installation location and the mechanical performance parameters, determine the boundary conditions; Based on the boundary conditions, the finite element model of the protective cover is determined when there are no internal stiffeners.

[0053] Specifically, the installation position between the protective cover and the machine tool body ensures that the effective contact area is located at the center of the support position, which allows the clamping force to be transmitted evenly along the symmetrical plane and avoids eccentric bending moment, thereby ensuring symmetrical pressure distribution on the mating surface, preventing loosening and making it less likely to cause the parts to tilt or be crushed locally.

[0054] The finite element model refers to the main structure of the protective cover except for the support position. The protective cover includes the main frame, the tool magazine protective door, the pneumatic protective door, the left and right sliding doors, the lubrication tool magazine door, the observation window, the door handle, the automatic protective door, the bellows mounting plate, etc. According to the actual situation of each component, spring units, RBE3 / RBR2, screw units, etc. are used to connect the components equivalently. The wall thickness of the main frame can be determined according to the thin wall thickness of the specimen model.

[0055] Boundary conditions include loads and constraints. Constraints include restrictions on the support location and degrees of freedom of moving parts, while loads include, but are not limited to, static loads, dynamic loads, and thermal loads. When determining boundary conditions, the support method of the protective shield is first mapped to the corresponding displacement / rotation constraints. Then, the mechanical performance data is converted into stiffness coefficients and load terms. Next, equilibrium conditions, geometric compatibility conditions, and physical relationships are used to determine which boundaries have known displacements and which are natural force boundaries. If the support contains gaps, friction, or nonlinear contact, the boundaries are written as constraint equations with state variables based on the performance data. If the reaction force at a certain support location conflicts with the performance data, that location is degenerated from simply supported / fixed support to an elastic support or the corresponding degrees of freedom are released. Thus, under the premise of mechanical equivalence, the boundary conditions reflect both the support location and satisfy the performance constraints.

[0056] Specifically, the protective cover model is meshed, and displacement / rotation constraints are applied to the corresponding nodes or element surfaces based on the support location and actual connection form. Then, concentrated forces, distributed pressures, temperature fields, or inertial loads are added as boundaries according to the load conditions. When contact, gap, or nonlinear supports are involved, contact pairs and spring elements are used to represent their mechanical behavior. It is checked whether the constraints eliminate rigid body displacement and whether the load and constraints are self-balancing. The finite element model is then constructed and the boundary conditions are injected.

[0057] This invention, in its embodiments, determines the installation position between the protective cover and the machine tool body based on the effective contact area between the screw joint and the protective cover; determines boundary conditions based on the installation position and the mechanical performance parameters; and determines the finite element model of the protective cover in the case of no internal stiffeners based on the boundary conditions. As one embodiment, the analysis of the finite element model based on multiple preset working conditions to determine the analysis results includes: The various working conditions are set as various positions of the moving parts of the protective cover and various mechanical states of the machine tool body; Finite element analysis is performed on the finite element model under any position of the moving part of the protective cover and any mechanical state of the machine tool body, and the deformation parameters and dynamic characteristic parameters of the protective cover under any working condition are used as the analysis results.

[0058] like Figure 7 and Figure 8As shown, the protective cover includes a top cover 201, a main body 202, a front door 203, a front door glass 204, a right door 205, a rear door 206, a lower cover 207, a left door 208, a left door glass 209, an electrical maintenance door 210, an electrical maintenance door glass 211, a right wiring trough 212, and a left wiring trough 213. The top cover 201 is installed on top of the main body 202, which sits on top of the lower cover 207. The front door 203 is located on the front of the protective cover, the right door 205 is located on the right side of the protective cover, and the rear door 206 is located on the back of the protective cover. The left side is provided with a left door 208 with an observation window, a left door glass 209, and an electrical maintenance door 210. Furthermore, the top of the protective cover has a right wiring trough 212 and a left wiring trough 213 on both sides for wiring arrangement and routing.

[0059] The moving parts have multiple positions, including the origin, midpoint, and full stroke position. The equivalent methods of the moving parts include, but are not limited to, center of mass equivalence and force equivalence. To reduce the scale of the analysis, the tool magazine protective door, pneumatic protective door, left and right sliding door, lubrication tool magazine door, observation window, door handle, etc. in the protective cover can be equivalent by mass point. Center of mass equivalence includes, but is not limited to, the position of the center of mass and the three-dimensional rotational inertia.

[0060] Multiple mechanical states include dynamic, static, and thermodynamic states. Dynamic states include, but are not limited to, modal analysis, harmonic response analysis, and start-stop impact characteristics. External loads include, but are not limited to, servo motor electromagnetic torque, cutting force, and thermal load. The magnitude of external loads can be calculated through experiments and relevant theoretical formulas.

[0061] Finite element analysis includes mesh generation, material parameter assignment, load equivalence, connection and contact settings, analysis settings, and obtaining analysis results. Mesh generation includes, but is not limited to, solid mesh generation, beam element mesh generation, and shell element mesh generation. Connection and contact settings include, but are not limited to, spring elements and contact elements.

[0062] The analysis results include, but are not limited to, static deformation values, thermal deformation values, frequency response results, and machine tool natural frequencies of key parts of the protective cover.

[0063] In this embodiment of the invention, the various working conditions are set as multiple positions of the moving parts of the protective cover and multiple mechanical states of the machine tool body. Under any position of the moving parts of the protective cover and any mechanical state of the machine tool body, finite element analysis is performed on the finite element model, and the deformation parameters and dynamic characteristic parameters of the protective cover under any working condition are used as the analysis results. By analyzing multiple working conditions, version iterations can be reduced, and the CNC machine tool can achieve higher machining accuracy during the use stage.

[0064] As an example, such as Figure 9 As shown, based on the analysis results, the coordinated optimization of the screw mounting position between the screw joint and the protective cover, the rib layout at the support position, and the rib layout inside the protective cover includes: Based on the analysis results, the response indicators required for collaborative optimization are determined, and based on the response indicators, the constraints required for collaborative optimization are determined. Based on the constraints and the preset objective function, the screw installation position between the screw joint and the protective cover, the rib layout at the support position, and the rib layout inside the protective cover are optimized collaboratively.

[0065] Optionally, the response indicators include the deformation value, modal frequency value, compliance index, temperature value, volume fraction, and mass fraction of the key nodes of the protective cover. The compliance index is used to characterize the optimization weight coefficient of the various working conditions. The objective function includes maximizing structural stiffness, minimizing temperature standard deviation, minimizing volume fraction, minimizing comprehensive weight coefficient, and minimizing compliance index. The constraints include modal frequency constraints, deformation value constraints, mass fraction constraints, process performance constraints, and stiffener height constraints.

[0066] Design constraints include, but are not limited to, modal frequency constraints, deformation value constraints of nodes in different locations, and mass fraction constraints. Topology optimization constraints include minimum member size constraints and minimum gap constraints, among which the minimum gap is used to ensure the spacing between screws after optimization. Morphology optimization constraints include rib height constraints. Process constraints are implemented using simple processes, which can ensure material cost savings without increasing process costs, so that the new design is likely to be approved. These constraints include, but are not limited to, symmetry constraints and linear constraints.

[0067] Optionally, based on the constraints and a preset objective function, the coordinated optimization of the screw mounting position between the screw joint and the protective cover, the rib layout at the support position, and the rib layout inside the protective cover includes: The optimization variables for the rib layout at the screw installation position and the support position are set as the unit density of the screw joint and the support component corresponding to the support position, respectively. The rib layout at the screw installation position and the support position is optimized based on the unit density to satisfy the constraints and the objective function. The optimization variable for the rib layout inside the protective cover is set as the displacement of the nodes inside the protective cover; The layout of the ribs inside the protective cover is optimized by adjusting the displacement to satisfy the constraints and the objective function.

[0068] like Figure 10 The diagram illustrates the structural principles and specific classifications of rib plate combinations. The foundation is the combination of morphological optimization of rib formation with the original sheet metal shape, resulting in three different layout forms: U-shaped, linear, and V-shaped. The topology optimization design variable is the element density of each element at the screw joint and support positions; the morphological optimization design variable is the displacement of internal nodes. The structural shape of the finite element model is continuously adjusted until the optimal combination of nodes that meets the design objectives is obtained. Morphological optimization requires determining parameters such as the area requiring rib formation, rib height, width, and rib angle. The rib formation can be set according to actual working conditions, including but not limited to cross-shaped ribs, grid-like ribs, and radiating ribs. Based on the actual situation, the relevant rib plates are welded to the inside of the protective cover.

[0069] like Figure 11 As shown, the design parameters of the stiffener include the width, height and rib angle of the stiffener. Each design parameter can be set according to the actual situation. In order to ensure that the machine tool protective cover has a flat and beautiful appearance, the stretching direction of the stiffener is along the normal direction of the unit and points to the inside of the protective cover.

[0070] In a preferred embodiment, the optimized area of ​​the protective cover can also be determined according to the installation position of the protective cover. The optimized area of ​​the protective cover is any position other than the installation position and the connection area, including but not limited to the front, rear, upper, left, right and lower sides of the protective cover and the various components that make up the protective cover. Each optimized area can be realized by segmentation model.

[0071] In a preferred embodiment, the present invention can also determine the weights of topology optimization and morphology optimization conditions respectively, define optimization algorithms, and perform collaborative topology optimization design on the internal stiffeners of the protective cover, the screw joints at the support positions, and the layout of the stiffeners. The weights of each condition are determined according to the actual situation of the condition. The higher the frequency of each condition during operation, the higher its topology optimization weight coefficient.

[0072] This invention fully considers the mutual influence between the installation position of the machine tool protective cover, the screw layout, and the internal rib layout. It collaboratively optimizes the screw installation position between the screw joint and the protective cover, the rib layout at the support position, and the rib layout inside the protective cover. Topology optimization is used to optimize the optimal number of screws and rib layout. Shape optimization is used to arrange the ribs of the protective cover, and welding is used to attach the ribs to the inside of the protective cover, reducing the use of stamping processes, further reducing space occupation and manufacturing costs, increasing the rigidity of the protective cover, and reducing weight. Optimizing the rib arrangement can shorten the development cycle. This invention can provide the support width, rib layout, screw layout and number, and a reasonable internal rib layout of the protective cover during the design phase, reducing the number of expensive prototype productions and whole-machine tests, avoiding repeated version iterations in later stages, and improving the efficiency of machine tool design.

[0073] As an example, such as Figure 12 As shown, after the coordinated optimization of the rib layout at the screw mounting position and support position between the screw joint and the protective cover, as well as the rib layout inside the protective cover, the method further includes: An optimized structural model of the protective cover is determined. If the optimized structural model meets the preset installation and processing conditions, the geometric model of the optimized structural model is reconstructed to obtain the geometric model of the protective cover. The geometric model is subjected to stiffener size optimization and sensitivity analysis. If the sensitivity analysis results meet the sensitivity conditions, the optimized geometric model is used as the target model of the protective cover.

[0074] The optimized structural model includes the layout and number of screw joints between the machine tool body and the protective cover, as well as the layout and form of the ribs that make up the inside of the protective cover.

[0075] In this embodiment of the invention, an optimized structural model of the protective cover is determined. When the optimized structural model meets preset installation and processing conditions, a geometric model reconstruction is performed on the optimized structural model to obtain the geometric model of the protective cover. The geometric model undergoes rib size optimization and sensitivity analysis. If the sensitivity analysis results meet the sensitivity conditions, the optimized geometric model is used as the target model of the protective cover. The optimized structural model is then verified to ensure the accuracy and reliability of the CNC machine tool during service.

[0076] As one embodiment, the geometric model reconstruction of the optimized structural model to obtain the geometric model of the protective shield includes: Based on the rib layout, number of ribs, rib type, and screw mounting hole positions and spacing inside the protective cover, the optimized structural model is geometrically reconstructed and locally adjusted to obtain the geometric model of the protective cover. The local adjustments include adjustments to the fillets and chamfers.

[0077] In this embodiment of the invention, a new dimensional model is established for the optimized structural model that meets the requirements, reinforcing ribs and screw mounting holes are arranged, and local adjustments are made. The new dimensional model is a complete protective cover model that meets the installation and processing requirements, including the internal rib layout, number and form of the ribs, and the screw mounting hole positions and spacing of the protective cover. The screw mounting holes are designed according to the topology optimization material distribution to open the protective cover, and the local adjustments include, but are not limited to, the adjustment of sheet metal bending rounded corners and chamfers.

[0078] As one embodiment, the step of optimizing the stiffener dimensions and performing sensitivity analysis on the geometric model includes: Based on the stiffness value and natural frequency under preset working conditions, the optimization objective is determined; Based on the sheet metal bending and welding parameters of the stiffener, the key dimensions of the stiffener are determined to optimize the stiffener size; Sensitivity analysis is performed based on the correspondence between the optimized stiffener dimensions and the optimization target.

[0079] Specifically, dimensional optimization includes sensitivity analysis of key dimensions such as stiffener thickness and optimization targets to obtain the correspondence between each structural dimension and the optimization target. The value range of key dimensions should be comprehensively evaluated in conjunction with the actual sheet metal bending and welding difficulty. The sensitivity analysis optimization targets include, but are not limited to, stiffness values ​​and natural frequencies under given working conditions. The stiffness values ​​at different locations are equivalently calculated based on the parameters of the actual operating conditions of the machine tool.

[0080] The table below compares the relevant performance indicators before and after the optimization of this invention. As can be seen from the table, this invention can reduce deformation, increase the first-order frequency, and improve the performance of the protective cover.

[0081] Table 1

[0082] This invention determines the optimization target based on the stiffness value and natural frequency under preset working conditions; it determines the key dimensions of the stiffener based on the sheet metal bending and welding parameters of the stiffener to optimize the stiffener size; and it performs sensitivity analysis based on the correspondence between the optimized stiffener size and the optimization target, which can further optimize the protective cover.

[0083] The design apparatus for CNC machine tool protective covers provided by the present invention is described below. The design apparatus for CNC machine tool protective covers described below and the design method for CNC machine tool protective covers described above can be referred to in correspondence with each other.

[0084] Figure 13 This is a structural schematic diagram of the design device for the CNC machine tool protective cover provided by the present invention, as shown below. Figure 13 As shown, the present invention also provides a design device for a CNC machine tool protective cover, comprising: Module 1310 is used to construct the machine tool body, protective cover, and screw joints of the CNC machine tool model; The first determining module 1320 is used to determine the finite element model of the protective cover without internal stiffeners based on the effective contact area between the screw joint and the protective cover, and the mechanical performance parameters of the screw joint. The second determining module 1330 is used to analyze the finite element model based on multiple preset working conditions and determine the analysis results. The analysis results include the deformation parameters and dynamic characteristic parameters of the protective cover under various working conditions. The optimization module 1340 is used to perform collaborative optimization on the screw installation position between the screw joint and the protective cover, the rib layout at the support position, and the rib layout inside the protective cover based on the analysis results, so as to complete the design of the protective cover.

[0085] As one embodiment, the first determining module 1320 is configured to: Based on the effective contact area between the screw joint and the protective cover, the installation position between the protective cover and the machine tool body is determined. Based on the installation location and the mechanical performance parameters, determine the boundary conditions; Based on the boundary conditions, the finite element model of the protective cover is determined when there are no internal stiffeners.

[0086] As one embodiment, the optimization module 1340 is used for: Based on the analysis results, the response indicators required for collaborative optimization are determined, and based on the response indicators, the constraints required for collaborative optimization are determined. Based on the constraints and the preset objective function, the screw installation position between the screw joint and the protective cover, the rib layout at the support position, and the rib layout inside the protective cover are optimized collaboratively.

[0087] As one embodiment, the optimization module 1340 is used for: The optimization variables for the rib layout at the screw installation position and the support position are set as the unit density of the screw joint and the support component corresponding to the support position, respectively. The rib layout at the screw installation position and the support position is optimized based on the unit density to satisfy the constraints and the objective function. The optimization variable for the rib layout inside the protective cover is set as the displacement of the nodes inside the protective cover; The layout of the ribs inside the protective cover is optimized by adjusting the displacement to satisfy the constraints and the objective function.

[0088] As one embodiment, the optimization module 1340 is used for: An optimized structural model of the protective cover is determined. If the optimized structural model meets the preset installation and processing conditions, the geometric model of the optimized structural model is reconstructed to obtain the geometric model of the protective cover. The geometric model is subjected to stiffener size optimization and sensitivity analysis. If the sensitivity analysis results meet the sensitivity conditions, the optimized geometric model is used as the target model of the protective cover.

[0089] As one embodiment, the optimization module 1340 is used for: Based on the layout, number, type, and screw mounting hole positions and spacing of the internal ribs of the protective cover, the optimized structural model is geometrically reconstructed and locally adjusted to obtain the geometric model of the protective cover. The local adjustments include adjustments to the fillets and chamfers. Based on the stiffness value and natural frequency under preset working conditions, the optimization objective is determined; Based on the sheet metal bending and welding parameters of the stiffener, the key dimensions of the stiffener are determined to optimize the stiffener size; Sensitivity analysis is performed based on the correspondence between the optimized stiffener dimensions and the optimization target.

[0090] It should be noted that the design device for CNC machine tool protective covers provided by the present invention has the same technical effects as the design method for CNC machine tool protective covers described above, and will not be repeated here.

[0091] Figure 14 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 14 As shown, the electronic device may include: a processor 1410, a communications interface 1420, a memory 1430, and a communication bus 1440, wherein the processor 1410, the communications interface 1420, and the memory 1430 communicate with each other via the communication bus 1440. The processor 1410 can call logical instructions in the memory 1430 to execute a design method for a CNC machine tool protective cover, the method including: The machine tool body, protective cover, and screw joints are used to construct the CNC machine tool model; Based on the effective contact area between the screw joint and the protective cover, and the mechanical performance parameters of the screw joint, the finite element model of the protective cover in the case of no internal stiffeners is determined. The finite element model is analyzed based on multiple preset working conditions to determine the analysis results, which include the deformation parameters and dynamic characteristic parameters of the protective cover under various working conditions. Based on the analysis results, the screw installation position between the screw joint and the protective cover, the rib layout at the support position, and the rib layout inside the protective cover are optimized in a coordinated manner to complete the design of the protective cover.

[0092] Furthermore, the logical instructions in the aforementioned memory 1430 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0093] On the other hand, the present invention also provides a computer program product, the computer program product comprising a computer program that can be stored on a non-transitory computer-readable storage medium, wherein when the computer program is executed by a processor, the computer is able to execute the design method for the CNC machine tool protective cover provided by the above methods, the method comprising: The machine tool body, protective cover, and screw joints are used to construct the CNC machine tool model; Based on the effective contact area between the screw joint and the protective cover, and the mechanical performance parameters of the screw joint, the finite element model of the protective cover in the case of no internal stiffeners is determined. The finite element model is analyzed based on multiple preset working conditions to determine the analysis results, which include the deformation parameters and dynamic characteristic parameters of the protective cover under various working conditions. Based on the analysis results, the screw installation position between the screw joint and the protective cover, the rib layout at the support position, and the rib layout inside the protective cover are optimized in a coordinated manner to complete the design of the protective cover.

[0094] In another aspect, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements a method for designing a CNC machine tool protective cover provided by the methods described above, the method comprising: The machine tool body, protective cover, and screw joints are used to construct the CNC machine tool model; Based on the effective contact area between the screw joint and the protective cover, and the mechanical performance parameters of the screw joint, the finite element model of the protective cover in the case of no internal stiffeners is determined. The finite element model is analyzed based on multiple preset working conditions to determine the analysis results, which include the deformation parameters and dynamic characteristic parameters of the protective cover under various working conditions. Based on the analysis results, the screw installation position between the screw joint and the protective cover, the rib layout at the support position, and the rib layout inside the protective cover are optimized in a coordinated manner to complete the design of the protective cover.

[0095] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0096] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0097] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A design method for a protective cover for a CNC machine tool, characterized in that, include: The machine tool body, protective cover, and screw joints are used to construct the CNC machine tool model; Based on the effective contact area between the screw joint and the protective cover, and the mechanical performance parameters of the screw joint, the finite element model of the protective cover in the case of no internal stiffeners is determined. The finite element model is analyzed based on multiple preset working conditions to determine the analysis results, which include the deformation parameters and dynamic characteristic parameters of the protective cover under various working conditions. Based on the analysis results, the screw installation position between the screw joint and the protective cover, the rib layout at the support position, and the rib layout inside the protective cover are optimized in a coordinated manner to complete the design of the protective cover.

2. The design method of the CNC machine tool protective cover according to claim 1, characterized in that, The determination of the finite element model of the protective cover without internal stiffeners, based on the effective contact area between the screw joint and the protective cover, and the mechanical property parameters of the screw joint, includes: Based on the effective contact area between the screw joint and the protective cover, the installation position between the protective cover and the machine tool body is determined. Based on the installation location and the mechanical performance parameters, determine the boundary conditions; Based on the boundary conditions, the finite element model of the protective cover is determined when there are no internal stiffeners.

3. The design method of the CNC machine tool protective cover according to claim 1, characterized in that, Based on the analysis results, the screw installation position between the screw joint and the protective cover, the rib layout at the support position, and the rib layout inside the protective cover are optimized collaboratively, including: Based on the analysis results, the response indicators required for collaborative optimization are determined, and based on the response indicators, the constraints required for collaborative optimization are determined. Based on the constraints and the preset objective function, the screw installation position between the screw joint and the protective cover, the rib layout at the support position, and the rib layout inside the protective cover are optimized collaboratively.

4. The design method of the CNC machine tool protective cover according to claim 3, characterized in that, Based on the constraints and a preset objective function, the following collaborative optimization is performed on the screw installation position between the screw joint and the protective cover, the rib layout at the support position, and the rib layout inside the protective cover: The optimization variables for the rib layout at the screw installation position and the support position are set as the unit density of the screw joint and the support component corresponding to the support position, respectively. The rib layout at the screw installation position and the support position is optimized based on the unit density to satisfy the constraints and the objective function. The optimization variable for the rib layout inside the protective cover is set as the displacement of the nodes inside the protective cover; The layout of the ribs inside the protective cover is optimized by adjusting the displacement to satisfy the constraints and the objective function.

5. The design method of the CNC machine tool protective cover according to claim 1, characterized in that, After optimizing the rib layout at the screw mounting position and support position between the screw joint and the protective cover, as well as the rib layout inside the protective cover, the process further includes: An optimized structural model of the protective cover is determined. If the optimized structural model meets the preset installation and processing conditions, the geometric model of the optimized structural model is reconstructed to obtain the geometric model of the protective cover. The geometric model is subjected to stiffener size optimization and sensitivity analysis. If the sensitivity analysis results meet the sensitivity conditions, the optimized geometric model is used as the target model of the protective cover.

6. The design method of the CNC machine tool protective cover according to claim 5, characterized in that, The step of reconstructing the geometric model of the optimized structural model to obtain the geometric model of the protective shield includes: Based on the rib layout, number of ribs, rib type, screw mounting hole positions and spacing inside the protective cover, the optimized structural model is geometrically reconstructed and locally adjusted to obtain the geometric model of the protective cover. The local adjustments include adjustments to the fillets and chamfers. The process of optimizing the stiffener dimensions and performing sensitivity analysis on the geometric model includes: Based on the stiffness value and natural frequency under preset working conditions, the optimization objective is determined; Based on the sheet metal bending and welding parameters of the stiffener, the key dimensions of the stiffener are determined to optimize the stiffener size; Sensitivity analysis is performed based on the correspondence between the optimized stiffener dimensions and the optimization target.

7. A design device for a protective cover for CNC machine tools, characterized in that, include: The building module is used to construct the machine tool body, protective cover, and screw joints of the CNC machine tool model; The first determining module is used to determine the finite element model of the protective cover without internal stiffeners based on the effective contact area between the screw joint and the protective cover, and the mechanical performance parameters of the screw joint. The second determining module is used to analyze the finite element model based on multiple preset working conditions and determine the analysis results. The analysis results include the deformation parameters and dynamic characteristic parameters of the protective cover under various working conditions. An optimization module is used to collaboratively optimize the screw installation position between the screw joint and the protective cover, the rib layout at the support position, and the rib layout inside the protective cover based on the analysis results, so as to complete the design of the protective cover.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, When the processor executes the computer program, it implements the design method of the CNC machine tool protective cover as described in any one of claims 1 to 6.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the design method of the CNC machine tool protective cover as described in any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the design method of the CNC machine tool protective cover as described in any one of claims 1 to 6.

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