Ball core lightweight design method, lightweight ball core, additive manufacturing process and ball valve

Abstract

This invention discloses a lightweight ball core design method, a lightweight ball core, an additive manufacturing process, and a ball valve, relating to the fields of mechanical component design and advanced manufacturing technology. The method achieves design through five steps: defining baseline working conditions, topology optimization of a configuration library, unified simulation comparison, quantitative evaluation and selection, and engineering refinement of the output model. Topology optimization applies process constraints, the truss structure employs a unit decomposition and recombination method, and a quantitative evaluation index system is also constructed. The lightweight ball core of this invention incorporates a single or composite internal support structure selected by this method, preferably a dumbbell-shaped composite structure with a central partition. Its additive manufacturing process uses selective laser melting of metal for integrated forming, with preheated substrate and pre-set powder venting holes in the model. A ball valve incorporating this ball core is also disclosed, enabling pre-manufacturability implementation, data-driven scientific decision-making, forming a design-structure-manufacturing closed loop, balancing lightweighting and mechanical performance, and improving the overall performance of the ball core and ball valve.

Description

Technical Field

[0001] This invention relates to the field of mechanical component design and advanced manufacturing technology, and more specifically to a lightweight ball core design method, a lightweight ball core, an additive manufacturing process, and a ball valve. Background Technology

[0002] As a core moving component in equipment in fields such as valves and aerospace, the structural design of the ball core directly affects the system inertia, drive energy consumption, operating accuracy and reliability of the equipment. Achieving lightweight design of the ball core is a key requirement for the high-performance and energy-saving development of high-end equipment.

[0003] Existing lightweight design methods for spherical cores are mainly divided into two categories: traditional empirical design and general topology optimization design. However, neither has effectively resolved the contradiction between weight reduction requirements, performance assurance, and manufacturing feasibility, making it difficult to apply the design results. The industry still lacks a systematic and engineering-based lightweight design solution for spherical cores, mainly due to the following two major technical pain points:

[0004] First, there is a severe disconnect between design and manufacturing, resulting in insufficient manufacturability. Traditional experience-based design relies on engineers' past design cases for structural improvements, which has limited lightweighting capabilities and makes it difficult to accurately balance the strength and stiffness of the sphere core. While general topology optimization methods can generate internal structures with theoretically excellent lightweighting effects through algorithms, the generated structures are often complex, chaotic, and irregular. They cannot be manufactured using traditional processes such as casting and machining. Even when additive manufacturing is used, issues such as excessively fine features and unreasonable support angles can easily lead to molding defects and loss of precision control, significantly increasing manufacturing costs and product scrap rates, resulting in the industry dilemma of "design feasible, manufacturing infeasible."

[0005] Secondly, design decisions lack scientific basis, and scheme selection is often arbitrary. Currently, the industry lacks systematic design guidelines for specific internal pressure load conditions in spherical cores. For common lightweight internal support configurations such as dumbbell shapes, partitions, trusses, and honeycomb structures, there is a lack of quantitative performance comparison data under unified and stringent standard operating conditions. This makes it impossible to clearly define the mechanical behavior, performance advantages and disadvantages, and key risk points of various configurations in spherical core application scenarios. Designers often rely on subjective judgment when selecting configurations, making it difficult to accurately match the differentiated requirements for lightweighting rate, stiffness, and strength in different application scenarios. This frequently leads to problems such as insufficient lightweighting, performance redundancy, or product failure due to localized stress concentration, resulting in low design efficiency and reliability.

[0006] Meanwhile, in existing technologies, the design and manufacturing of the ball core are separated. The design stage does not fully consider the technical characteristics of advanced processes such as additive manufacturing, and the manufacturing stage also finds it difficult to adapt the design scheme to the process, thus failing to transform the design freedom of advanced manufacturing technology into the performance advantage of the ball core.

[0007] Therefore, in response to the existing problems, how to provide a lightweight design method for ball cores that can integrate manufacturability into the design process in advance, achieve scientific design decisions through data-driven approaches, and develop a feasible optimized structure and additive manufacturing process, so as to solve the balance between performance and weight reduction from the design source, realize the integration of ball core design and manufacturing, and provide technical support for the lightweight upgrading of key moving parts of high-end equipment, is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0008] Therefore, this invention provides a lightweight design method for sphere cores based on configuration libraries and quantitative evaluation. This method integrates manufacturability into the design process in advance and enables data-driven scientific design decisions. It also forms a feasible optimized structure and additive manufacturing process, solving the balance between performance and weight reduction from the design source. This achieves the integration of sphere core design and manufacturing, providing technical support for the lightweight upgrading of key moving parts in high-end equipment.

[0009] To achieve the above objectives, the present invention adopts the following technical solution: A lightweight design method for a spherical core includes: S1: Define the baseline design domain and extreme conditions: Establish an initial solid model based on the nominal diameter of the target sphere core; set the internal pressure load, fixed constraint boundary conditions, and additive manufacturing-specific material properties it will bear; S2: Topology optimization generation based on the manufacturable configuration library: Under the condition of satisfying the additive manufacturing process constraints, topology optimization is performed to guide the generation of a variety of candidate basic configurations of internal support structures belonging to the preset manufacturable configuration library; the preset manufacturable configuration library includes at least dumbbell-shaped internal support structures, partition structures, truss structures, and honeycomb structures. S3: Comparison of parametric modeling and unified working condition simulation: Parametric modeling is performed on each candidate configuration, and finite element simulation is performed under a unified limit verification condition. The mass, maximum deformation, and maximum equivalent stress of each configuration are extracted and compared. S4: Quantitative comprehensive evaluation and optimal solution selection: Based on simulation data, a quantitative evaluation index system is constructed to calculate the lightweighting rate, relative stiffness, and strength safety factor of each solution; according to application requirements, the index weights are set for weighted scoring, and the overall optimal structure or composite structure is selected from the solutions that meet the strength safety threshold. S5: Engineering Refinement and Manufacturing Model Output: Optimizes the details of the selected solution and outputs a 3D digital model that can be directly used for additive manufacturing.

[0010] Through the above technical solutions, this invention provides a lightweight design method for spherical cores. As the core method claim, it establishes a full-process design method for lightweight spherical cores based on configuration libraries and quantitative evaluation. By defining the working conditions, optimizing the configuration library topology, unifying the simulation, quantitative evaluation, and refining the engineering process, manufacturability is brought forward from the design source. This solves the core pain points of design and manufacturing disconnect and blind solution selection in traditional lightweight spherical core design. It realizes the standardization and datafication of lightweight spherical core design, and can efficiently generate spherical core design schemes with high lightweight ratio, excellent mechanical properties, and compatibility with additive manufacturing. It provides a general and reproducible methodological framework for the subsequent lightweight design of various types of spherical cores.

[0011] Preferably, in the above-mentioned lightweight design method for a spherical core, in step S2, the topology optimization process applies minimum member size constraints and self-supporting angle constraints. The minimum member size is ≥2mm to ensure stable forming of the selective laser melting process. Adding process constraints of a minimum member size ≥2mm and a self-supporting angle to the topology optimization process specifically addresses problems such as forming defects, precision loss, and high scrap rates caused by excessively fine structural features and unreasonable support angles during additive manufacturing (selective laser melting). This ensures that the candidate configurations generated by topology optimization all meet the requirements of additive manufacturing processes, achieving direct matching between design results and manufacturing processes, significantly improving the feasibility of the design scheme, and reducing manufacturing costs.

[0012] Preferably, in the above-mentioned lightweight design method for spherical cores, in step S2, the optimization of the truss structure involves sequentially decomposing the internal space of the spherical core into several units along the main force transmission direction; starting from the constraint end, topology optimization is performed on each unit in sequence, and the nodal reaction forces at the interface of the previous unit optimization results are used as load inputs to the subsequent units; finally, the optimization results of each unit are combined and smoothed to form a complete spatial truss structure. By decomposing units along the main force transmission direction, sequentially optimizing, and transmitting nodal reaction forces, the problems of high overall optimization difficulty, unreasonable force transmission paths, and nodal stress concentration in traditional truss structure optimization are solved. The generated spatial truss structure has a clearer force transmission path and better mechanical performance, while retaining the advantages of high stiffness and high stability of truss structures, providing a precise and efficient optimization method for truss-type spherical core internal support structures.

[0013] Preferably, in the aforementioned lightweight ball core design method, in step S3, the unified limit verification condition involves the inner surface of the ball core fluid channel being subjected to uniform hydrostatic pressure, and a fixed constraint being applied to the channel opening at one end of the simulated valve stem connection. This unifies the limit verification condition for lightweight ball core design, clarifies the standardized simulation conditions of uniform hydrostatic pressure and fixed constraint at the valve stem end, and solves the problems of inconsistent conditions and lack of reference for performance data in simulation comparisons of different configurations. This makes the mass, deformation, and stress data of each candidate configuration directly comparable, providing an objective and unified benchmark for subsequent quantitative evaluation and ensuring the scientific nature of design decisions.

[0014] Preferably, in the above-mentioned lightweight design method for the ball core, in step S4, the calculation method of the quantitative evaluation index system is: lightweight rate η = (M0) / ( ... Mi) / M0, relative stiffness Krel=Dmax / Di, strength safety factor n=σs / σmax; weighted scoring formula is Si=wk Krel,i+wη ηi. A quantitative evaluation index system was constructed and the calculation method was clarified. By combining the quantitative calculation of lightweight rate, relative stiffness, and strength safety factor with weighted scoring, the core design decision was transformed from experience-based judgment to data-driven scientific selection. This solved the contradiction of difficulty in accurately balancing lightweight, stiffness, and strength in traditional design. It can select the optimal solution based on the weight requirements of different application scenarios, ensuring that the design results achieve the optimal balance of core performance indicators while meeting the strength safety threshold.

[0015] A lightweight ball core, wherein the ball core has an internal support structure selected and determined by the above design method, wherein the internal support structure is a single structure or a composite structure composed of multiple structures selected from a library of manufacturable configurations.

[0016] Through the above technical solution, the present invention provides a lightweight spherical core, which strongly correlates the lightweight spherical core structure with the aforementioned design method, ensuring that the internal support structure of the spherical core is the optimal result after standardized design, unified simulation, and quantitative evaluation and screening. This solves the problems of arbitrary design and unreliable performance of traditional spherical core internal support structures. The generated spherical core internal support structure can be a single configuration or a composite configuration, which can adapt to the differentiated requirements of lightweight and mechanical performance in different application scenarios. Moreover, the structure is highly compatible with additive manufacturing processes, laying a structural foundation for the high performance and lightweight of the spherical core.

[0017] Preferably, in the aforementioned lightweight spherical core, the internal support structure is a composite structure consisting of a dumbbell-shaped internal support structure and a central partition structure. The dumbbell-shaped internal support structure is provided with a support unit having an enlarged connecting part and a slender transmission part. The enlarged connecting part is connected to the inner wall of the spherical core, and the central partition structure is a continuous plate-shaped partition connected to the inner wall of the spherical core. This composite internal support structure, which defines the dumbbell-shaped internal support and the central partition, combines the advantages of the dumbbell-shaped structure (high axial force transmission efficiency and good lightweight effect) with the partition structure (high lateral stiffness and strong deformation resistance). It solves the problems of insufficient lightweighting, insufficient stiffness, or stress concentration in single-configuration spherical cores, achieving the optimal engineering balance between the spherical core's lightweight rate, stiffness, and strength safety margin. This composite structure, while ensuring extremely low deformation and low stress, is lighter than high-performance dense truss structures, significantly reducing material costs and system drive energy consumption, making it the optimal spherical core structure solution for general engineering scenarios.

[0018] An additive manufacturing process for lightweight spherical cores is disclosed, characterized by the use of selective laser melting (SLM) to integrally form a three-dimensional digital model of the lightweight spherical core, with preheating of the substrate during the forming process. This paper proposes an integrated SLM forming process adapted for lightweight spherical cores and clarifies the process requirements for substrate preheating. It solves the problems of traditional manufacturing processes being unable to form complex internally supported spherical cores, resulting in low precision and poor mechanical properties after forming. Through integrated additive manufacturing, the design features of the complex internal support structure of the spherical core are fully preserved. Simultaneously, substrate preheating effectively reduces thermal stress and warpage during printing, improving the forming accuracy and density of the spherical core, thus achieving integrated design and manufacturing of the spherical core.

[0019] Preferably, in the above-mentioned additive manufacturing process for lightweight ball cores, the three-dimensional digital model of the ball core has pre-set powder drainage holes. Pre-setting powder drainage holes in the three-dimensional model of the ball core solves the problem of unremovable powder inside the ball core during additive manufacturing, and the problem of residual powder affecting the assembly and operational accuracy of the ball core. This ensures that residual powder can be thoroughly cleaned through the powder drainage holes after printing, guaranteeing the internal cleanliness and assembly accuracy of the ball core. Furthermore, the pre-set powder drainage holes provide process adaptability design for additive manufacturing, further improving the process feasibility and finished product yield of the ball core manufacturing.

[0020] A ball valve, characterized in that it comprises the aforementioned lightweight ball core.

[0021] Through the above technical solution, this invention provides a ball valve that incorporates a lightweight ball core, integrating the core advantages of a lightweight ball core. This solves the problems of large ball core mass, high system inertia, high drive energy consumption, and low operating accuracy in traditional ball valves. It significantly reduces the drive energy consumption and system inertia of the ball valve, improves the opening and closing response speed and operating accuracy, and ensures the reliability and service life of the ball valve under high-pressure conditions through the excellent mechanical properties of the lightweight ball core. This upgrades the overall performance of the ball valve and makes it suitable for ball valve products in high-end equipment fields such as valves and aerospace.

[0022] As can be seen from the above technical solution, compared with the prior art, the present invention discloses a lightweight design method for spherical cores based on configuration library and quantitative evaluation, which has the following beneficial effects: 1. This invention constructs a systematic design process with manufacturability in the lead-in stage. By pre-setting a manufacturable configuration library adapted to additive manufacturing and applying process constraints in the topology optimization stage, it ensures from the design source that the internal support structure of the generated sphere core can be directly formed through additive manufacturing. This completely solves the industry pain point of the disconnect between design and manufacturing in traditional design, achieves seamless connection between design and manufacturing, and significantly reduces manufacturing costs and product scrap rate.

[0023] 2. This invention establishes a data-driven scientific design decision-making mechanism. It obtains quantitative performance data of each candidate configuration through finite element simulation under unified extreme working conditions, and performs weighted scoring by combining a quantitative evaluation index system constructed with lightweighting rate, relative stiffness, and strength safety factor. This transforms the spherical core design decision from subjective judgment based on experience into objective selection based on data, accurately balancing the core contradictions of lightweighting, stiffness, and strength, and ensuring that the selected scheme achieves optimal performance while meeting strength and safety requirements.

[0024] 3. This invention achieves standardization and reproducibility in lightweight sphere core design. From the definition of the baseline design domain and extreme conditions to the entire process of topology optimization, simulation comparison, and quantitative evaluation, clear technical specifications and calculation methods have been formulated. At the same time, specific optimization strategies for typical configurations such as truss structures have been defined, making this design method adaptable to lightweight sphere core designs of different specifications and application scenarios, providing the industry with a general and scalable technical paradigm.

[0025] 4. This invention forms a closed-loop solution encompassing the entire technology chain of design, structure, and manufacturing. It not only provides a scientific lightweight design method but also identifies the optimal composite spherical core structure combining a dumbbell-shaped internal support with a central partition. Furthermore, it is equipped with a suitable selective laser melting additive manufacturing process for metals, achieving integrated implementation from design to finished part. This composite structure integrates the performance advantages of different individual configurations, ensuring high rigidity and low stress while also achieving lightweight effects. The accompanying manufacturing process fully preserves the structural design features, improves the spherical core forming accuracy and density, and ultimately achieves a dual improvement in both high performance and lightweight design for the spherical core product.

[0026] 5. This invention reveals the mechanical behavior and risk points of different lightweight configurations under internal pressure loads in the sphere core. Through simulation comparison under unified working conditions, it clarifies the inapplicability of honeycomb structures under this working condition and the edge stress concentration of partition structures. It provides important theoretical guidance and practical basis for the selection and targeted optimization of lightweight configurations for sphere cores and similar mechanical components, effectively avoids design blindness, and improves the overall design efficiency and reliability of the industry. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present 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 only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0028] Figure 1 The attached figure is a cross-sectional view of the spherical dumbbell-shaped inner support structure provided by the present invention; Figure 2 The attached figure is a cloud diagram showing the total deformation distribution of the spherical core under stress in the dumbbell-shaped inner support structure provided by the present invention. Figure 3 The attached figure is a cloud diagram showing the equivalent stress distribution on the core of the dumbbell-shaped inner support structure provided by the present invention. Figure 4 The attached figure shows the point of maximum equivalent stress in the spherical dumbbell-shaped inner support structure provided by the present invention; Figure 5 The attached figure is a cross-sectional view of the partition-shaped spherical core structure provided by the present invention; Figure 6 The attached figure is a cloud diagram showing the total deformation distribution of the spherical core under stress in the spherical core structure provided by the present invention; Figure 7 The attached figure is a cloud diagram showing the equivalent stress distribution of the sphere core of the partition-shaped sphere core structure provided by the present invention; Figure 8The attached figure shows the point of maximum equivalent stress in the spherical core structure provided by this invention; Figure 9 The attached figure shows the truss-shaped internal support structure provided by the present invention; Figure 10 The attached figure is a cloud diagram showing the total deformation distribution of the spherical core under stress in the truss-shaped internal support structure provided by the present invention. Figure 11 The attached figure is a cloud diagram showing the equivalent stress distribution on the spherical core of the truss-shaped internal support structure provided by the present invention; Figure 12 The attached figure shows the point of maximum equivalent stress in the truss-shaped internal support structure provided by the present invention. Figure 13 The attached figure is a cross-sectional view of the honeycomb internal support structure provided by the present invention; Figure 14 The attached figure is a cloud diagram showing the total deformation distribution of the spherical core under stress in the honeycomb-shaped internal support structure provided by the present invention; Figure 15 The attached figure is a cloud diagram showing the equivalent stress distribution on the spherical core of the honeycomb internal support structure provided by the present invention; Figure 16 The attached figure shows the point of maximum equivalent stress in the honeycomb internal support structure provided by this invention; Figure 17 The attached figure is a structural cross-sectional view of the encrypted truss-shaped internal support structure provided by the present invention; Figure 18 The attached figure is a cloud diagram showing the total deformation distribution of the spherical core under stress in the encrypted truss-shaped internal support structure provided by the present invention. Figure 19 The attached figure is a cloud diagram showing the equivalent stress distribution on the spherical core of the encrypted truss-shaped internal support structure provided by the present invention; Figure 20 The attached figure shows the point of maximum equivalent stress in the encrypted truss-shaped internal support structure provided by the present invention. Figure 21 The attached figure is a flowchart of the lightweight design method for the sphere core of the present invention. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Example 1: See appendix Figure 1-21 This invention discloses a lightweight design method for a spherical core. This embodiment uses a DN50 ball valve core as the implementation object. The material selected is 316L stainless steel, which is specially used for additive manufacturing. Its elastic modulus is 193GPa, Poisson's ratio is 0.28, and yield strength is 560MPa. The technical solution of the present invention will be described in detail.

[0031] Specifically, the internal support structure can be a dumbbell-shaped internal support structure, including at least one support unit with an enlarged connection and an elongated transmission part; the internal support structure can be a partition structure, including at least one continuous plate-shaped partition that divides the cavity; the internal support structure can be a truss structure, including a spatial truss system composed of multiple members connected by nodes; the internal support structure can be a composite structure, composed of two or more of the following: dumbbell-shaped internal support structure, partition structure, truss structure, and honeycomb structure.

[0032] The lightweight design of the DN50 sphere core according to the design method of this invention is carried out in the following steps: S1: Define the baseline design domain and extreme working conditions: Establish an initial solid model of the sphere core with a nominal diameter of DN50. The initial model mass is about 1.36 kg. Set the extreme working condition as the inner surface of the fluid channel of the sphere core is subjected to a uniform hydrostatic pressure of 3 MPa. Apply a fixed constraint to the channel opening at one end of the valve stem connection. The material properties adopt the performance parameters of the above-mentioned additive manufacturing-specific 316L stainless steel. S2: Topology optimization generation based on the manufacturable configuration library: Apply process constraints of minimum member size ≥ 2 mm and truss structure self-support angle > 45°, perform topology optimization, and guide the generation of six candidate internal support structures, including dumbbell-shaped internal support, diaphragm, basic truss, honeycomb, densified optimized truss, dumbbell-shaped and central diaphragm composite structure. The truss structure is optimized by the element decomposition and recombination method. The internal space of the sphere core is sequentially decomposed into several elements along the main force transmission direction. Starting from the constraint end, each element is optimized in turn and the reaction force of the interface node is transmitted. Finally, the elements are combined smoothly to form a complete spatial truss. S3: Comparison of Parametric Modeling and Unified Working Condition Simulation: Parametric 3D modeling was performed on the six candidate configurations. Finite element simulation was conducted under the unified limit condition in step S1 to extract the mass, maximum deformation, and maximum equivalent stress of each configuration. The simulation results are as follows: ① Dumbbell-shaped internal support: mass 0.246 kg, maximum deformation 0.0285 mm, maximum stress 190.37 MPa; ② Partition structure: mass 0.261 kg, maximum deformation 0.0196 mm, maximum stress 291.84 MPa; ③ Foundation truss structure ① Frame structure: mass 0.271kg, maximum deformation 0.0182mm, maximum stress 209.17MPa; ② Honeycomb structure: mass 0.335kg, maximum deformation 0.0173mm, maximum stress 369.10MPa; ③ Optimized truss structure: mass 0.372kg, maximum deformation 0.0111mm, maximum stress 116.60MPa; ④ Composite structure (dumbbell shape and partition): mass 0.350kg, maximum deformation 0.0112mm, maximum stress 189.36MPa.S4: Quantitative Comprehensive Evaluation and Optimal Scheme Selection: Setting a strength safety threshold n≥2.0, stiffness weight wk=0.5, and lightweighting rate weight wη=0.5, calculate the lightweighting rate, relative stiffness, strength safety factor, and weighted total score for each configuration. The results are: ① Dumbbell-shaped internal support: η=0.819, Krel=1.00, n=2.94, S=0.910; ② Partition structure: η=0.808, Krel=1.45, n=1.92, S=1.129; ③ Basic truss structure: η=0.801, Krel=1.57, n=2.68, S=1.185; ④ Honeycomb structure: η=0.754, Krel=1.65, n=1.52, S=1.202; ⑤ Dense optimized truss structure: η=0.726, Krel=2.57, n=4.80, S=1.648; ⑥ Composite structure (dumbbell shape and partition): η=0.743, Krel=2.54, n=2.96, S=1.642. First, the partition structure (②) and honeycomb structure (④) were excluded because their strength safety factors did not meet the requirements. Among the remaining compliant configurations, the weighted total score of the composite structure (⑥) was close to that of the dense optimized truss structure (⑤), and it was approximately 5.9% lighter, resulting in the best overall engineering benefits. Therefore, it was selected as the final design scheme. S5: Engineering Refinement and Manufacturing Model Output: Optimize the details of the selected composite structure sphere core, open a Φ3mm powder discharge hole on the sphere core body, and after completing the process feature design, output a three-dimensional digital model that can be directly used for additive manufacturing.

[0033] In some specific examples, in step S2, the topology optimization process applies minimum member size constraints and self-supporting angle constraints, wherein the minimum member size is ≥2mm, to ensure stable forming of the selective laser melting process.

[0034] In some other embodiments, in step S2, the optimization of the truss structure involves sequentially decomposing the internal space of the sphere core into several units along the main force transmission direction; starting from the constraint end, performing topology optimization on each unit in sequence, and using the nodal reaction force at the interface of the previous unit optimization result as a load input to the subsequent unit; finally, combining and smoothing the optimization results of each unit to form a complete space truss structure.

[0035] In a specific embodiment, in step S3, the unified limit verification condition is that the inner surface of the ball core fluid channel is subjected to uniform hydrostatic pressure, and a fixed constraint is applied to the channel opening at one end of the simulated valve stem connection.

[0036] In a specific example, in step S4, the calculation method of the quantitative evaluation index system is: lightweight rate η = (M0) / (M0) Mi) / M0, relative stiffness Krel=Dmax / Di, strength safety factor n=σs / σmax; weighted scoring formula is Si=wk Krel,i+wη ηi.

[0037] Specifically, the calculation method for the quantitative evaluation index system is as follows: Lightweighting rate η = (M0) The formulas are: Mi / M0, relative stiffness Krel=Dmax / Di, strength safety factor n=σs / σmax; where M0 is the initial solid model mass, Mi is the candidate configuration mass, Dmax is the maximum deformation of all candidate configurations, Di is the deformation of a single candidate configuration, σs is the material yield strength, and σmax is the maximum equivalent stress of the candidate configuration; the weighted scoring formula is Si=wk Krel,i+wη ηi and wk are stiffness weights, and wη is a weight for lightweighting rate.

[0038] Example 2: See appendix Figure 1-21 This invention discloses a lightweight sphere core, wherein the sphere core has an internal support structure selected and determined by the design method in Embodiment 1. The internal support structure is a single structure or a composite structure composed of multiple structures selected from the manufacturable configuration library.

[0039] In some examples, the lightweight sphere core is a DN50 specification, comprising a sphere core body. Inside the sphere core body is a composite internal support structure consisting of a dumbbell-shaped inner support structure and a central partition structure. Fluid channels are provided on the sphere core body, and powder drainage holes are located on its sidewalls. The dumbbell-shaped inner support structure includes two symmetrically arranged support units. Each support unit has an enlarged connection portion that connects to the inner wall of the sphere core body and a slender transmission portion connecting the two, achieving efficient axial force transmission. The central partition structure is a continuous plate-shaped partition that connects to both the inner wall of the sphere core body and the outer wall of the fluid channels, enhancing lateral stiffness. The two structures work synergistically to ensure high stiffness and low stress mechanical properties while maintaining a lightweight sphere core.

[0040] Example 3: See appendix Figure 1-21 This invention discloses an additive manufacturing process for a lightweight ball core, used to manufacture the lightweight ball core in Example 2. The process involves using selective laser melting (SLM) to integrally form the three-dimensional digital model of the lightweight ball core, with the substrate being preheated during the forming process.

[0041] In a specific embodiment, selective laser melting (SLM) of metal is used to integrally form the lightweight sphere core of Example 2. The specific steps are as follows: Process preparation: The three-dimensional digital model of the sphere core output from Example 1 is imported into the additive manufacturing equipment, and the model slicing and processing path planning are completed; Equipment debugging: The substrate is preheated to 80°C, nitrogen gas is introduced into the forming cavity until the oxygen content is <0.1%, the laser power is set to 200W, the scanning speed is 800mm / s, the scanning spacing is 0.06mm, the powder layer thickness is 30μm, and the interlayer scanning vector is rotated by 67°; Integral forming: The equipment is started, and selective laser melting is performed according to the planned path to complete the integral printing of the sphere core; Post-processing: After printing, the sphere core is sandblasted to remove powder, and the residual powder inside the sphere core is cleaned through the powder discharge hole 8; The sphere core is separated from the substrate by wire cutting; The powder discharge hole 8 is welded and sealed; Finally, the necessary surface treatment is performed to obtain the finished sphere core. The finished ball core was tested and found to have a dimensional accuracy error of <0.1mm, a density of >99.5%, and a microhardness of 205±8HV0.1, which fully meets the design and engineering requirements.

[0042] Example 4: See appendix Figure 1-21 This invention discloses a ball valve comprising the lightweight ball core of Embodiment 2, and is equipped with conventional ball valve components such as a valve stem, valve body, and seals. The valve stem is fixedly connected to the valve stem connection end of the lightweight ball core, enabling the rotational opening and closing of the ball core. Due to the use of the lightweight ball core of this invention, the system inertia of this ball valve is significantly reduced, the driving energy consumption is reduced by approximately 60% compared to traditional ball valves, and the opening and closing response speed is increased by approximately 50%. Furthermore, under high pressure conditions of 3MPa, the ball core exhibits no significant deformation or stress concentration, significantly improving the operating accuracy and reliability of the ball valve. It is suitable for high-pressure, high-precision applications in aerospace, high-end fluid control, and other fields.

[0043] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0044] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A lightweight design method for a spherical core, characterized in that, include: S1: Define the baseline design domain and limit conditions: Establish an initial solid model based on the nominal diameter of the target sphere core; Define the internal pressure load it can withstand, the fixed constraint boundary conditions, and the properties of additive manufacturing-specific materials; S2: Topology optimization generation based on the manufacturable configuration library: Under the condition of satisfying the additive manufacturing process constraints, topology optimization is performed to guide the generation of a variety of candidate basic configurations of internal support structures belonging to the preset manufacturable configuration library; the preset manufacturable configuration library includes at least dumbbell-shaped internal support structures, partition structures, truss structures, and honeycomb structures. S3: Comparison of parametric modeling and unified working condition simulation: Parametric modeling is performed on each candidate configuration, and finite element simulation is performed under a unified limit verification condition. The mass, maximum deformation, and maximum equivalent stress of each configuration are extracted and compared. S4: Quantitative comprehensive evaluation and optimal solution selection: Based on simulation data, a quantitative evaluation index system is constructed to calculate the lightweighting rate, relative stiffness, and strength safety factor of each solution; according to application requirements, the index weights are set for weighted scoring, and the overall optimal structure or composite structure is selected from the solutions that meet the strength safety threshold. S5: Engineering Refinement and Manufacturing Model Output: Optimizes the details of the selected solution and outputs a 3D digital model that can be directly used for additive manufacturing.

2. The lightweight design method for a spherical core according to claim 1, characterized in that, In step S2, the topology optimization process applies minimum member size constraints and self-supporting angle constraints, wherein the minimum member size is ≥2mm, to ensure stable forming of the selective laser melting process.

3. The lightweight design method for a spherical core according to claim 2, characterized in that, In step S2, the optimization of the truss structure involves sequentially decomposing the internal space of the sphere core into several units along the main force transmission direction; starting from the constraint end, topology optimization is performed on each unit in sequence, and the nodal reaction force at the interface of the previous unit optimization result is used as a load input to the subsequent unit; finally, the optimization results of each unit are combined and smoothed to form a complete space truss structure.

4. The lightweight design method for a spherical core according to claim 3, characterized in that, In step S3, the unified limit verification condition is that the inner surface of the ball core fluid channel is subjected to uniform hydrostatic pressure, and a fixed constraint is applied to the channel opening at one end of the simulated valve stem connection.

5. The lightweight design method for a spherical core according to claim 4, characterized in that, In step S4, the calculation method for the quantitative evaluation index system is: lightweight rate η = (M0) / ( ... Mi) / M0, relative stiffness Krel=Dmax / Di, strength safety factor n=σs / σmax; The weighted scoring formula is Si=wk Krel,i+wη ηi.

6. A lightweight sphere core, wherein the sphere core has an internal support structure selected and determined by the design method of any one of claims 1-5, wherein the internal support structure is a single structure or a composite structure composed of multiple structures selected from a library of manufacturable configurations.

7. A lightweight spherical core according to claim 6, characterized in that, The internal support structure is a composite structure consisting of a dumbbell-shaped internal support structure and a central partition structure. The dumbbell-shaped internal support structure is provided with a support unit having an enlarged connecting part and a slender transmission part. The enlarged connecting part is connected to the inner wall of the sphere core. The central partition structure is a continuous plate-shaped partition connected to the inner wall of the sphere core.

8. An additive manufacturing process for a lightweight spherical core, characterized in that, For manufacturing the lightweight spherical core according to any one of claims 6-7, characterized in that a three-dimensional digital model of the lightweight spherical core is integrally formed by selective laser melting of metal, and the substrate is preheated during the forming process.

9. The additive manufacturing process for a lightweight spherical core according to claim 8, characterized in that, The three-dimensional digital model of the ball core has a pre-set powder discharge hole.

10. A ball valve, characterized in that, It includes the lightweight ball core as described in claim 6 or 7.

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