Parameter-driven three-dimensional process model rapid generation method

Abstract

The invention provides a parameter-driven three-dimensional process model rapid generation method, and belongs to the field of computer-aided process planning. The method comprises the following steps: firstly, analyzing structural characteristics and a process route of a part, establishing a three-dimensional process template of each process, and forming a three-dimensional process template library; according to the three-dimensional process template, parameterized control over the structure and size of a process model is achieved by establishing parameter constraint and expression association. Secondly, part parameters are obtained according to geometric and process characteristics of the part, and process parameters of all processes are obtained through calculation according to the parameter mapping relation during part process decision making. And finally, in combination with a CAD (Computer Aided Design) platform, driving an expression in the process template to change by using the process parameters, and realizing rapid generation of a three-dimensional model of each process. According to the method, parameterized reuse and automatic generation of the three-dimensional process model are realized, and the efficiency and consistency of part process modeling are remarkably improved.

Description

Technical Field

[0001] This invention belongs to the field of computer-aided process planning, specifically relating to a parameter-driven method for rapid generation of three-dimensional process models. Background Technology

[0002] With the continuous improvement of the level of intelligence and digitalization in the manufacturing industry, the three-dimensional process model, as the core carrier of three-dimensional process design, carries the dynamic evolution information of the geometric state of parts in each process, and has become a key foundation for realizing process visualization, simulation optimization and digital integration of the manufacturing process.

[0003] Currently, the manufacturing process of complex parts typically involves more than ten machining steps. Each step corresponds to the geometric state of the part at a specific machining stage. Traditional 3D process modeling methods often rely on designers manually modifying the model in the CAD system to generate intermediate models for different stages. This method is inefficient, involves a large amount of repetitive work, and is prone to model deviations due to manual operation errors, making it difficult to meet the requirements of high reliability and high consistency.

[0004] To improve process design efficiency, existing technologies achieve reverse modeling from finished product models to blank models by identifying machining features and combining them with decision information, thus improving modeling efficiency to some extent. This method relies on a feature modeling information database and predefined modeling operations. Existing technologies also propose a feature mapping-based reverse generation method for process models. This method constructs a feature mapping database, extracts the surface topological features of parts, and transforms design features into machining features, thereby generating a 3D process model. While this method mentions "process parameter information," it does not establish a dynamic mapping relationship between process parameters and the process model, leading to significant repetitive work in the process model generation process when dealing with highly similar parts.

[0005] Therefore, a parameter-driven method for rapid generation of 3D process models is proposed, which can balance modeling efficiency, flexibility and consistency, and realize the evolution of 3D process modeling of parts from design model to blank model, thereby serving subsequent simulation, process verification and manufacturing process integration. Summary of the Invention

[0006] The technical problem to be solved: To avoid the shortcomings of existing technologies, this invention provides a parameter-driven method for rapid generation of 3D process models. By combining parameter-driven methods, template libraries, and parameter mapping relationships, efficient and consistent generation of 3D process models is achieved.

[0007] The technical solution of this invention is: a parameter-driven method for rapid generation of three-dimensional process models, comprising the following steps: Step 1. Building a 3D process template library: For a target family of parts, analyze its part features and process features, and extract part parameters, including structural parameters and process parameters. The typical process route of the part family is established based on the part composite method. The part composite method includes: creating a composite part model that contains all structural elements in the part family, and sorting out and determining typical process routes covering various types of parts based on the composite part model. For each step in the typical process route, a parameter-driven three-dimensional process template is created; wherein, the three-dimensional process template is associated with predefined parameter constraints and expressions to achieve parameterized control of the process model structure and size; Establish and store parameter mapping relationships, which define the mathematical or rule-based transformation relationships between the part parameters and the process parameters of each process, and associate them with the corresponding three-dimensional process templates to form a reusable three-dimensional process template library. Step 2. Initialization of New Part Process Design: Obtain the design model of the new part, analyze it, and extract its part parameters; Based on the part parameters, a template matching mechanism is used to retrieve and select matching typical process routes and corresponding three-dimensional process template sets from the three-dimensional process template library; Step 3. Automatic calculation of process parameter chain: For the selected process route, based on the parameter mapping relationship, and with the part parameters of the new part as input, the process parameters of each process covering the blanking process to the finished product process are automatically calculated to form a process parameter chain. Step 4. Automatic generation of 3D process model: Map each process parameter in the process parameter chain to drive the expression in the corresponding three-dimensional process template; By utilizing a parametric modeling engine integrated with a 3D CAD platform, the geometric model is automatically reconstructed based on the driven expression, and a 3D process model covering each process state from blank to finished product is generated sequentially. A further technical solution of the present invention is that, in step 1, the construction of the three-dimensional process template library shall at least satisfy the following constraints: The three-dimensional process templates are classified, stored, and named according to a three-level index structure of "part family - process category - feature type", which enables hierarchical retrieval of templates based on part family tags, process categories, and feature types; Each 3D process template predefines the dimensional parameters, positional parameters, and process parameters required to drive its geometric model, and associates these parameters with template features through geometric topological constraints, so that the template maintains the consistency and integrity of its geometric topology when the parameters change.

[0008] A further technical solution of the present invention is that the parameter mapping relationship includes at least one of the following forms: Linear mapping relationship: Based on linear addition and subtraction operations of machining allowance, the outer diameter of the process = the outer diameter of the part + the roughing allowance, that is, proc_wj = p_wj + m_roughing, where proc_wj is the outer diameter of the process, p_wj is the outer diameter of the part, and m_roughing is the roughing allowance; the thickness of the process = the thickness of the part + the roughing allowance + the semi-finishing allowance, that is, proc_hd = p_hd + m_roughing + m_semifine, where proc_hd is the thickness of the process, p_hd is the thickness of the part, m_roughing is the roughing allowance, and m_semifine is the semi-finishing allowance; Nonlinear mapping relationship: The process parameter is a function of the part parameter or process parameter. The process inner diameter = part inner diameter × (1 + finishing allowance coefficient), that is, proc_nj = p_nj × (1 + m_fine), where proc_nj is the process inner diameter, p_nj is the part inner diameter, and m_fine is the finishing allowance coefficient; the process chamfer size is a function of the surface roughness grade, that is, c_chamfer = f(Ra), where Ra is the surface roughness grade, and f(Ra) is a nonlinear function, expressed as follows:

[0009] This function is applicable to surface roughness grades in the range of Ra = 0.8 to 6.3 μm; Rule table mapping relationship: The process parameters are determined based on the process decision rules. The condition items of the process decision rules include at least one of the following: processing method, tool type, machine tool capability, and clamping method.

[0010] A further technical solution of the present invention is that the specific value of the nonlinear function f(Ra) is: When Ra = 0.8, c_chamfer = 0.5mm; When Ra = 1.6, c_chamfer = 0.3mm; When Ra = 3.2, c_chamfer = 0.2mm; When Ra = 6.3, c_chamfer = 0.1mm.

[0011] A further technical solution of the present invention is: the structural parameters in the part parameters are a subset of the part parameters, used to characterize the main geometric features of the part, and as direct variables in the template expression. The structural parameters include at least the outer diameter, inner diameter, thickness and dimensions of key features. Process parameters are attributes related to machining requirements or resources, including machining allowance, tolerance, rough / finishing classification, surface roughness grade, and tool type selection constraints.

[0012] A further technical solution of the present invention is: the template matching mechanism in step 2 is: based on the part family label, structural similarity and process characteristics of the new part, it is matched with the template classification information in the three-dimensional process template library, and the most suitable set of typical process templates and corresponding parameter mapping relationships are retrieved and selected.

[0013] A further technical solution of the present invention is: in step 3, the calculation of the process parameter chain adopts a backward algorithm, specifically as follows: Starting with the process parameters of the finished product process, and combining the machining allowance and process method determined by the parameter mapping relationship, the geometric dimensions and process parameters of the previous process are calculated back step by step until the blank process.

[0014] A further technical solution of the present invention is: in the back calculation, the value of the machining allowance is determined by querying a predefined rule table, wherein the condition item of the rule table is the part structure parameter, and the corresponding rough machining allowance and semi-finishing allowance are matched according to the part thickness range.

[0015] A further technical solution of the present invention is: in step 4, the synchronous modeling technology of the 3D CAD platform is used to write the parameters of each process into the model expression in the 3D process template, and trigger the expression evaluation and synchronous modeling engine of the 3D CAD platform to automatically complete the reconstruction and updating of the geometric model, so as to realize the rapid generation of the 3D process model. A three-dimensional process model generation system, comprising: A template library construction module is used to build and store a 3D process template library for a target part family; wherein, the 3D process template library includes: A multi-parameter-driven 3D process template created based on the typical process route of the part family; In addition, a predefined parameter mapping relationship, which defines the conversion rules between part parameters and process parameters of each process; The parameter extraction and template matching module is used to obtain the design model of the new part and extract the part parameters from it; based on the part parameters, it automatically retrieves and matches the corresponding typical process route and three-dimensional process template set from the three-dimensional process template library; The process parameter chain calculation module is used to automatically calculate and generate the process parameters for each process from the blanking process to the finished product process based on the parameter mapping relationship and the part parameters of the new part as input, thereby forming a complete process parameter chain. The model generation driver module is used to transmit each process parameter in the process parameter chain and drive the corresponding three-dimensional process template. Through the integration interface with the three-dimensional software platform, it triggers the three-dimensional software platform to automatically reconstruct the geometric model, thereby generating all three-dimensional process models of the new part in batches.

[0016] A further technical solution of the present invention is that the system is integrated with at least one of the three-dimensional CAD platforms, such as UG / NX, CATIA, or SolidWorks, and parameter transfer and model driving are realized by calling the secondary development interface of the platform.

[0017] Beneficial effects The beneficial effects of this invention are as follows: By constructing a parameterized three-dimensional process template library and establishing a dynamic mapping relationship from part parameters to process parameters, this invention achieves the automated and intelligent generation of three-dimensional process models, and has the following significant beneficial effects: 1. In practical applications, for disc-shaped parts, the generation time of the three-dimensional process model of the present invention can be significantly shortened, such as from the traditional hour level to the minute level, and the efficiency is significantly improved.

[0018] 2. This invention associates predefined parameter mapping relationships with expressions, and all process models are automatically generated by the same set of parameter chains, ensuring a high degree of consistency and accuracy in geometric dimensions and process logic for all intermediate states from blank to finished product, fundamentally avoiding human error.

[0019] 3. The three-dimensional process template library constructed in this invention is a digital realization of the "part composite method" and group process concept. It encapsulates excellent process design experience and best practices for a certain type of part family into parameterizable and reusable intelligent assets. When process engineers are dealing with new parts, they do not need to start from scratch; they can simply use template matching to call up mature process solutions. A typical disk-type part template library can cover the process design of 20 to 40 similar parts, significantly reducing the threshold for process design and the dependence on specific expert experience, thus realizing the preservation and appreciation of enterprise knowledge assets. Attached Figure Description

[0020] Figure 1 This is a flowchart illustrating the overall process of a parameter-driven method for rapidly generating a three-dimensional process model according to an embodiment of the present invention. Figure 2 This is a flowchart illustrating the reverse generation process of a 3D process model in an embodiment of the present invention. Figure 3 This is a process model generation diagram in an embodiment of the present invention. Detailed Implementation

[0021] The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the invention, and should not be construed as limiting the invention.

[0022] To improve efficiency, the industry has proposed several automated or semi-automated solutions. For example: Methods based on feature recognition and reverse deletion (such as CN118314279A) generate the preceding process model by identifying machining features (such as holes, slots, and fillets) on the finished product model and reversing these features according to the process route. This method is effective for simple parts, but its core is geometric "subtraction," lacking support for process decision-making logic (such as allowance allocation and tolerance transfer). It is poorly adaptable to complex parts that require dynamic calculation of intermediate dimensions and have nonlinear mapping relationships, and it is difficult to handle scenarios where "addition" (such as process bosses) is required during the process.

[0023] Methods based on fixed process templates (such as CN119376335A) utilize predefined process knowledge bases and resource libraries to generate toolpaths and process cards by matching machining features. These methods focus on the "information flow" of process planning, but their outputs are process documents and toolpaths, rather than the 3D process model itself, thus failing to solve the fundamental problem of automatic 3D model construction.

[0024] The method of secondary development based on a specific CAD platform (such as CN102722614A) achieves the conversion of design models into process models through secondary development in environments such as Pro / E. This method is limited by specific software platforms, has poor versatility, high development and maintenance costs, and its dynamic feature creation process still does not break away from the underlying interactive modeling logic, failing to form a reusable parametric knowledge system.

[0025] In summary, existing technologies have shortcomings in areas such as automatic geometry generation, process logic encapsulation, and system versatility. In particular, they lack a mechanism for deeply, dynamically, and automatically associating part design parameters, process decision rules, and the geometric representation of the 3D model. This results in significant repetitive work during process design when dealing with families of parts with similar structures and standard process routes, hindering the rapid, accurate, and consistent generation of 3D process models. Therefore, this invention proposes a parameter-driven method for rapid generation of 3D process models, comprising the following steps: Step 1. Building a 3D process template library: For a target family of parts, analyze its part features and process features, and extract part parameters, including structural parameters and process parameters. The typical process route of the part family is established based on the part composite method. The part composite method includes: creating a composite part model that contains all structural elements in the part family, and sorting out and determining typical process routes covering various types of parts based on the composite part model. For each step in the typical process route, a parameter-driven three-dimensional process template is created; wherein, the three-dimensional process template is associated with predefined parameter constraints and expressions to achieve parameterized control of the process model structure and size; Establish and store parameter mapping relationships, which define the mathematical or rule-based transformation relationships between the part parameters and the process parameters of each process, and associate them with the corresponding three-dimensional process templates to form a reusable three-dimensional process template library. Step 2. Initialization of New Part Process Design: Obtain the design model of the new part, analyze it, and extract its part parameters; Based on the part parameters, a template matching mechanism is used to retrieve and select matching typical process routes and corresponding three-dimensional process template sets from the three-dimensional process template library; Step 3. Automatic calculation of process parameter chain: For the selected process route, based on the parameter mapping relationship, and with the part parameters of the new part as input, the process parameters of each process covering the blanking process to the finished product process are automatically calculated to form a process parameter chain. Step 4. Automatic generation of 3D process model: Map each process parameter in the process parameter chain to drive the expression in the corresponding three-dimensional process template; By utilizing a parametric modeling engine integrated with a 3D CAD platform, the geometric model is automatically reconstructed based on the driven expression, and a 3D process model covering each process state from blank to finished product is generated sequentially. This invention also proposes a three-dimensional process model generation system, comprising: A template library construction module is used to build and store a 3D process template library for a target part family; wherein, the 3D process template library includes: A multi-parameter-driven 3D process template created based on the typical process route of the part family; In addition, a predefined parameter mapping relationship, which defines the conversion rules between part parameters and process parameters of each process; The parameter extraction and template matching module is used to obtain the design model of the new part and extract the part parameters from it; based on the part parameters, it automatically retrieves and matches the corresponding typical process route and three-dimensional process template set from the three-dimensional process template library; The process parameter chain calculation module is used to automatically calculate and generate the process parameters for each process from the blanking process to the finished product process based on the parameter mapping relationship and the part parameters of the new part as input, thereby forming a complete process parameter chain. The model generation driver module is used to transmit each process parameter in the process parameter chain and drive the corresponding three-dimensional process template. Through the integration interface with the three-dimensional software platform, it triggers the three-dimensional software platform to automatically reconstruct the geometric model, thereby generating all three-dimensional process models of the new part in batches.

[0026] The above technical solution will be further illustrated with examples below: In one embodiment, refer to Figure 1 As shown in the figure, a parameter-driven method for rapid generation of 3D process models in this embodiment includes the following steps: Step 1: Analyze the part characteristics and process characteristics of this type of part to extract part parameters, including structural and process parameters. Based on the "part composite method," establish a typical process for this type of part, including process routes and typical operations. Using the part parameters, calculate the operation parameters for each operation. For each operation, establish a parameter-driven 3D operation template, determine the mapping relationship between operation parameters and the 3D operation model, and form a reusable 3D operation model template library, referred to as the operation template library.

[0027] Step 2: When designing the process for a new part, first analyze and extract the part parameters from the design model, and then use a template matching mechanism to retrieve and select the most suitable process route and corresponding process template.

[0028] Step 3: For each process, based on the parameter mapping relationship, calculate the process parameters of the last process from the part parameters, and then calculate the required geometric dimensions and related parameters of the previous process in turn, until the blank process.

[0029] Step 4: Map the calculated process parameters to the expressions in the model construction, realize the dynamic change of the 3D model through parameter-driven method, generate the 3D process model of the corresponding process, until the complete process model chain from design model to blank model is completed.

[0030] Step 5: Transfer the generated process model back to each process to complete the process design of the new part.

[0031] Step one is the stage of establishing the three-dimensional process template library, and steps two to five are the stages of rapid generation of three-dimensional process models.

[0032] Specifically, the construction mechanism of the process template library in step one follows the following specific constraints: (1) Template classification and naming conventions: The templates are categorized into three levels: "Part Family - Process Category - Feature Type," including templates for blanks, rough machining, semi-finishing, and finishing, making them reusable and searchable. Template names follow a unified naming convention: [Part Type]_[Process Type]_[Process Sequence], ensuring uniqueness, readability, and searchability.

[0033] (2) Completeness of template parameter constraints: Each template must contain all the parameters required to drive the process model, including dimensional parameters (such as outer diameter and thickness), positional parameters, and process parameters (such as allowances and chamfer radii). Missing parameters that prevent the expression from being solved are prohibited. Furthermore, geometric features must satisfy geometric topological constraints (such as concentricity and parallelism between holes and outer diameters).

[0034] Specifically, the part parameters in step one are: a set of parameters describing the overall or stage-specific geometric state of the part, which can be divided into structural parameters and process parameters.

[0035] Specifically, the structural parameters in step one are a subset of the part parameters used to characterize the main geometric features of the part (such as step height, boss width, hole coordinates, etc.) and serve as direct variables in the template expression.

[0036] Specifically, the process parameters in step one are attributes related to processing requirements or resources, such as machining allowance, allowable tolerance, rough / finishing classification, surface roughness grade, tool type selection constraints, etc.

[0037] Specifically, the process parameters in step one are: a set of parameters used to describe the geometry and process state of a part under a certain process, which are direct values ​​that drive the three-dimensional process template expression (such as the hole diameter, chamfer size, allowance value, positioning datum, etc. of a certain process).

[0038] In one embodiment, the parameter mapping relationship in step one refers to the mathematical or rule-based relationship (which can be an expression, linear / nonlinear mapping, or rule table) between part parameters, structural parameters, process parameters, and operation parameters, defined and stored in the template library during the library construction phase. Specifically, it includes the following forms: The linear mapping relationship is as follows: Process outer diameter = part outer diameter + roughing allowance, i.e., proc_wj = p_wj + m_roughing, where proc_wj is the process outer diameter, p_wj is the part outer diameter, and m_roughing is the roughing allowance; Process thickness = part thickness + roughing allowance + semi-finishing allowance, i.e., proc_hd = p_hd + m_roughing + m_semifine, where proc_hd is the process thickness, p_hd is the part thickness, m_roughing is the roughing allowance, and m_semifine is the semi-finishing allowance. The nonlinear mapping relationship is as follows: Process inner diameter = Part inner diameter × (1 + Finishing allowance coefficient), i.e., proc_nj = p_nj × (1 + m_fine), where proc_nj is the process inner diameter, p_nj is the part inner diameter, and m_fine is the finishing allowance coefficient; Process chamfer size = a function of surface roughness grade, i.e., c_chamfer = f(Ra), where Ra is the surface roughness grade, and f(Ra) is a nonlinear function, expressed as follows:

[0039] This function is applicable to surface roughness grades in the range of Ra = 0.8 to 6.3 μm; Preferably, when Ra = 0.8, c_chamfer = 0.5mm; When Ra = 1.6, c_chamfer = 0.3mm; When Ra = 3.2, c_chamfer = 0.2mm; When Ra = 6.3, c_chamfer = 0.1mm.

[0040] Rule table mapping relationship: Rules for determining process parameters based on process parameters (such as machining method, tool type, machine tool capability), for example: When the machining method is "rough turning" and the tool type is "carbide", the process outer diameter tolerance is ±0.05mm; When the machining method is "finish turning" and the tool type is "ceramic", the process outer diameter tolerance is ±0.02mm; When the clamping method is a "three-jaw chuck" and the part thickness is >100mm, the process thickness tolerance is ±0.03mm.

[0041] The above mapping relationships are defined through parameter constraints and expression association during the template library establishment phase and stored as structured data to ensure that the process parameters of each process can be calculated accurately and quickly during the process decision-making phase.

[0042] Preferably, the component composite method in step one is: for a class of similar components, construct a virtual composite component that includes all the typical structural elements of that class of components, and perform a unified process analysis on the composite component to obtain a group process design method that can cover the typical process routes of that class of components.

[0043] Preferably, the template matching mechanism in step two refers to: retrieving and selecting the most suitable set of typical process templates and their corresponding parameter mapping relationships based on part family tags, structural similarity, and process feature matching.

[0044] Preferably, the back-calculation method for process parameters in step three is as follows: A backward-calculation or forward-recursive algorithm is used to calculate the process parameter value for each process based on the selected decision strategy and parameter mapping relationship. The back-calculation method (commonly used in reverse engineering scenarios) starts with the finished product process and, combined with process information such as machining allowance, machining method, machine tool capabilities, and clamping limitations, calculates the geometric and process parameters required for the previous process step by step. Preferably, the parameter-driven mechanism in step four is as follows: using the engine of 3D CAD, the parameters of each process are mapped to the expression of model construction, such as stretching height, chamfer size, hole size, etc., and the dynamic change of the 3D model is realized through numerical driving, and the corresponding process model is automatically generated.

[0045] In one embodiment, taking a certain type of turbine disk in aircraft engine disk-type parts as an example, the implementation details of this method (parameter-driven rapid generation method of 3D process model) are explained completely and step by step: Step 1: Analyze the part characteristics and process characteristics of disc-shaped parts, establish typical processes, and define their typical process routes (blank - rough turning - semi-finish turning - finish turning - finished product).

[0046] Step 2: Import the turbine disk design model into UG / NX software. The part parameters will be automatically identified through the UG embedded parameter interface, including: ① Structural parameters: outer diameter, inner diameter, disk thickness, annular groove width, annular groove depth, etc.

[0047] ② Process parameters: roughing / finishing allowance, tool nose radius, surface roughness, etc.

[0048] The parameters are categorized, and the identification results are written into the "Part Parameter Table" using structured records, including name / content / standard value / superscript / subscript / parameter type / parameter category, to provide data input for subsequent process decisions and template mapping.

[0049] Step 3: Establish a turbine disk process model template library I. Process Model Template Library: In the UG / NX environment, based on the process analysis results, corresponding process models are established for the key processes of various parts. Using UG's Product Template Studio (PTS) function, the above process models are uniformly named and classified according to part type and process category, and stored uniformly in UG's reuse library to build a typical part process model template library, realizing centralized management and resource reuse of templates.

[0050] Table 1:

[0051] Step 3: Calculation of process parameters 1. Example of linear mapping based on machining allowance Starting with the "finished product process", and combining the machining allowance and process sequence, a recursive algorithm is used to calculate the geometric and process parameters of the preceding process to form a "process parameter chain".

[0052] The finished outer diameter of this turbine disk is (p3_wj = 612) mm, with a final allowance of 0.5 mm. The semi-finished outer diameter is (p2_wj = p3_wj + 0.5 = 612.5) mm; The rough outer diameter is (p1_wj = p2_wj + 1.0 = 613.5) mm; The outer diameter of the wool fabric is (p0_wj = p1_wj + 1.5 = 615) mm.

[0053] By using a similar recursive relationship, the geometric parameters required for each process can be derived step by step, realizing the layer-by-layer transfer of parameters.

[0054] 2. Example of process decision parameter mapping based on rule tables For disc-shaped parts with different thickness ranges, this invention uses a rule table to determine the machining allowance. For example:

[0055] For the turbine disk thickness in this embodiment: hd=122 mm (belonging to hd ≥ 60), therefore, it is automatically determined that: .

[0056] Generate parameter chains for processes such as roughing and semi-finishing.

[0057] Raw material process parameters

[0058] Roughing process parameters

[0059] Step 4: Process Model Template Matching and Parameter Mapping Match the turbine disk corresponding process model template from the process model template library, and then bind the process parameters generated by the process decision to the template expression driving point to establish a parameter mapping relationship table to ensure the accuracy of parameter transmission.

[0060] The bound process parameter values ​​are written into the UG model expression. The UG system automatically triggers the UG expression evaluation / synchronous modeling engine according to the change of the expression. The geometric structure in the template is automatically reconstructed according to the new parameters to generate the three-dimensional process model of the process.

[0061] Step 5: Starting from the final process model (finished product), generate each process model in the order of "finished product - rear end of machine - front end of machine - process ring groove - blank". Save each process model as an intermediate version and update the parameters. When the model backtracks to the point of no machining features, the blank model generation is completed.

[0062] To highlight the advantages of this invention, the embodiments of this invention are compared with the background technology below: 1. Compare with the "Automatic Synchronous Modeling Reverse Generation Method" (201910981667.7)

[0063] 2. Compare with the "Reverse Generation Method of Process Model Based on Feature Mapping" (202310415288.8)

[0064] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. A parameter-driven method for rapid generation of 3D process models, characterized in that, Includes the following steps: Step 1. Building a 3D process template library: For a target family of parts, analyze its part features and process features, and extract part parameters, including structural parameters and process parameters. The typical process route of the part family is established based on the part composite method. The part composite method includes: creating a composite part model that contains all structural elements in the part family, and sorting out and determining typical process routes covering various types of parts based on the composite part model. For each step in the typical process route, a parameter-driven three-dimensional process template is created; wherein, the three-dimensional process template is associated with predefined parameter constraints and expressions to achieve parameterized control of the process model structure and size; Establish and store parameter mapping relationships, which define the mathematical or rule-based transformation relationships between the part parameters and the process parameters of each process, and associate them with the corresponding three-dimensional process templates to form a reusable three-dimensional process template library. Step 2. Initialization of New Part Process Design: Obtain the design model of the new part, analyze it, and extract its part parameters; Based on the part parameters, a template matching mechanism is used to retrieve and select matching typical process routes and corresponding three-dimensional process template sets from the three-dimensional process template library; Step 3. Automatic calculation of process parameter chain: For the selected process route, based on the parameter mapping relationship, and with the part parameters of the new part as input, the process parameters of each process covering the blanking process to the finished product process are automatically calculated to form a process parameter chain. Step 4. Automatic generation of 3D process model: Map each process parameter in the process parameter chain to drive the expression in the corresponding three-dimensional process template; By utilizing a parametric modeling engine integrated with a 3D CAD platform, the geometric model is automatically reconstructed based on the driven expression, and a 3D process model covering each process state from blank to finished product is generated sequentially.

2. The parameter-driven method for rapid generation of three-dimensional process models according to claim 1, characterized in that: In step 1, the construction of the three-dimensional process template library shall at least satisfy the following constraints: The three-dimensional process templates are classified, stored, and named according to a three-level index structure of "part family - process category - feature type", which enables hierarchical retrieval of templates based on part family tags, process categories, and feature types; Each 3D process template predefines the dimensional parameters, positional parameters, and process parameters required to drive its geometric model, and associates these parameters with template features through geometric topological constraints, so that the template maintains the consistency and integrity of its geometric topology when the parameters change.

3. The parameter-driven method for rapid generation of three-dimensional process models according to claim 2, characterized in that: The parameter mapping relationship includes at least one of the following forms: Linear mapping relationship: Based on linear addition and subtraction operations of machining allowance, the outer diameter of the process = the outer diameter of the part + the roughing allowance, that is, proc_wj = p_wj + m_roughing, where proc_wj is the outer diameter of the process, p_wj is the outer diameter of the part, and m_roughing is the roughing allowance; the thickness of the process = the thickness of the part + the roughing allowance + the semi-finishing allowance, that is, proc_hd = p_hd + m_roughing + m_semifine, where proc_hd is the thickness of the process, p_hd is the thickness of the part, m_roughing is the roughing allowance, and m_semifine is the semi-finishing allowance; Nonlinear mapping relationship: The process parameter is a function of the part parameter or process parameter. The process inner diameter = part inner diameter × (1 + finishing allowance coefficient), that is, proc_nj = p_nj × (1 + m_fine), where proc_nj is the process inner diameter, p_nj is the part inner diameter, and m_fine is the finishing allowance coefficient; the process chamfer size is a function of the surface roughness grade, that is, c_chamfer = f(Ra), where Ra is the surface roughness grade, and f(Ra) is a nonlinear function, expressed as follows: This function is applicable to surface roughness grades in the range of Ra = 0.8 to 6.3 μm; Rule table mapping relationship: The process parameters are determined based on the process decision rules. The condition items of the process decision rules include at least one of the following: processing method, tool type, machine tool capability, and clamping method.

4. The parameter-driven method for rapid generation of three-dimensional process models according to claim 3, characterized in that: The specific values ​​of the nonlinear function f(Ra) are as follows: When Ra = 0.8, c_chamfer = 0.5mm; When Ra = 1.6, c_chamfer = 0.3mm; When Ra = 3.2, c_chamfer = 0.2mm; When Ra = 6.3, c_chamfer = 0.1mm.

5. The parameter-driven method for rapid generation of three-dimensional process models according to claim 1, characterized in that: The structural parameters in the part parameters are a subset of the part parameters used to characterize the main geometric features of the part and serve as direct variables in the template expression. The structural parameters include at least the outer diameter, inner diameter, thickness, and dimensions of key features. Process parameters are attributes related to machining requirements or resources, including machining allowance, tolerance, rough / finishing classification, surface roughness grade, and tool type selection constraints.

6. The parameter-driven method for rapid generation of three-dimensional process models according to claim 1, characterized in that: The template matching mechanism in step 2 is as follows: based on the part family label, structural similarity and process characteristics of the new part, it is matched with the template classification information in the three-dimensional process template library, and the most suitable set of typical process templates and corresponding parameter mapping relationships are retrieved and selected.

7. The parameter-driven method for rapid generation of three-dimensional process models according to claim 1, characterized in that: In step 3, the calculation of the process parameter chain adopts a backward algorithm, specifically as follows: Starting with the process parameters of the finished product process, and combining the machining allowance and process method determined by the parameter mapping relationship, the geometric dimensions and process parameters of the previous process are calculated back step by step until the blank process.

8. The parameter-driven method for rapid generation of three-dimensional process models according to claim 1, characterized in that: In the back calculation, the value of the machining allowance is determined by querying a predefined rule table. The condition items of the rule table are the structural parameters of the part, and the corresponding roughing allowance and semi-finishing allowance are matched according to the thickness range of the part.

9. The parameter-driven method for rapid generation of three-dimensional process models according to claim 1, characterized in that: In step 4, the synchronous modeling technology of the 3D CAD platform is used to automatically reconstruct and update the geometric model by writing the parameters of each process into the model expression in the 3D process template and triggering the expression evaluation and synchronous modeling engine of the 3D CAD platform, so as to achieve rapid generation of the 3D process model.

10. A three-dimensional process model generation system, used to execute the parameter-driven rapid generation method for three-dimensional process models according to any one of claims 1-9; characterized in that, include: A template library construction module is used to build and store a 3D process template library for a target part family; wherein, the 3D process template library includes: A multi-parameter-driven 3D process template created based on the typical process route of the part family; In addition, a predefined parameter mapping relationship, which defines the conversion rules between part parameters and process parameters of each process; The parameter extraction and template matching module is used to obtain the design model of the new part and extract the part parameters from it; based on the part parameters, it automatically retrieves and matches the corresponding typical process route and three-dimensional process template set from the three-dimensional process template library; The process parameter chain calculation module is used to automatically calculate and generate the process parameters for each process from the blanking process to the finished product process based on the parameter mapping relationship and the part parameters of the new part as input, thereby forming a complete process parameter chain. The model generation driver module is used to transmit each process parameter in the process parameter chain and drive the corresponding three-dimensional process template. Through the integration interface with the three-dimensional software platform, it triggers the three-dimensional software platform to automatically reconstruct the geometric model, thereby generating all three-dimensional process models of the new part in batches.

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