Variable density lattice cell, clamp, and method of making a clamp

Abstract

This invention relates to the field of insulator clamp technology, and provides a variable-density lattice unit, including a frame and a support for load transfer. The support is disposed within the frame and occupies 0-100% of the space volume within the frame. A clamp and a method for manufacturing the clamp are also provided. This invention changes the density of the lattice unit by altering the volume occupied by the support within the frame, thus making the load force borne by the lattice unit variable. When applied to a clamp, lattice units of different densities can be filled according to different stress zones of the clamp, significantly reducing the mass of the clamp while meeting the clamp strength requirements.

Description

Technical Field

[0001] This invention relates to the field of clamping technology, specifically to a variable density lattice unit, a clamp, and a method for manufacturing the clamp. Background Technology

[0002] In the operation and maintenance of ultra-high voltage transmission lines, live-line insulator replacement is a crucial task. Insulator clamps, as key tools in the replacement, installation, and disassembly of insulator strings, play an irreplaceable role, placing extremely high demands on their structure in terms of reliability, safety, and ease of operation. Currently, the traditional insulator clamps widely used in engineering practice are mostly integral aluminum alloy or steel solid structures. These clamps generally suffer from problems such as large weight, complex assembly processes, and limited applicability. In field or high-altitude work scenarios, these clamps not only increase the carrying burden and operational difficulty for workers but also significantly increase the risk of worker fatigue and misoperation. Furthermore, the structural design of existing insulator clamps typically uses homogeneous materials and solid filling methods, failing to fully consider the non-uniform characteristics of stress and deformation distribution in different structural areas under actual working conditions, resulting in low material utilization and limited potential for lightweighting. In terms of manufacturing processes, traditional machining technologies are limited by forming paths, internal structural complexity, and parameter customization capabilities, making it difficult to meet the precision manufacturing needs of multi-scale complex structures.

[0003] Therefore, the specific problems with traditional card holders are as follows:

[0004] 1. Heavy structural weight: The aluminum alloy or steel clamps currently in use generally weigh more than 30kg. This not only seriously affects the portability and operational efficiency of live-line work, but also places a heavy physical burden on workers, especially in high-altitude outdoor work environments.

[0005] 2. Low material utilization efficiency: Traditional solid structures fail to optimize the design according to stress distribution, and there is a lack of differentiated treatment between high-stress and low-stress areas, resulting in the accumulation of redundant materials and low resource utilization.

[0006] 3. Poor adaptability and versatility: The fixed clamp structure lacks a flexible adjustment mechanism, making it difficult to be compatible with insulator steel caps of different specifications and models, thus limiting its versatility;

[0007] 4. High manufacturing complexity: Complex components usually require multiple stages of machining and manual assembly, resulting in a cumbersome process and poor consistency of parts, which increases the manufacturing cycle and cost.

[0008] 5. Weak ability to adjust structural performance: It is impossible to carry out local reinforcement design according to the load characteristics of different parts, resulting in an uneven distribution of structural stiffness and safety margin, which affects the reliability of use;

[0009] 6. Significant limitations in manufacturing methods: Existing structural forms lack topology optimization or lattice construction adaptability, making it difficult to achieve structural integration with metal additive manufacturing technology, thus limiting the ability to form functionally integrated and complex structures. Summary of the Invention

[0010] The purpose of this invention is to provide a variable density lattice unit, a fixture, and a method for manufacturing the fixture, which can at least solve some of the defects in the prior art.

[0011] To achieve the above objectives, the present invention provides the following technical solution: a variable density lattice unit, including a frame and a support for load transfer, wherein the support is disposed within the frame and occupies 0 to 100% of the space volume within the frame.

[0012] Furthermore, the support includes a base and at least two inner rods, one end of which is connected to the frame and the other end of which is connected to the base. The base is fixed in the space within the frame by the inner rods.

[0013] Furthermore, the frame includes a plurality of connecting rods, each of which forms a cubic structure.

[0014] Furthermore, some of the connecting rods are arc-shaped rods used to alleviate stress concentration at the corners.

[0015] This invention provides another technical solution: a clamping device, including an upper body and a lower body, the upper body and the lower body enclosing a clamping area, and further including the aforementioned variable density lattice unit, wherein the upper body and the lower body are each filled with a plurality of the aforementioned variable density lattice units.

[0016] Furthermore, both the upper body and the lower body have an arched portion and a connecting portion. The arched portion of the upper body and the arched portion of the lower body enclose the clamping area, and the connecting portion of the upper body and the connecting portion of the lower body are connected.

[0017] Furthermore, the arched portion is divided into a top layer, a middle layer, and a bottom layer along the direction from the outer diameter to the inner diameter. The top layer, the middle layer, and the bottom layer are all filled with the variable density lattice units. The number of variable density lattice units filled in the top layer is less than the number of variable density lattice units filled in the middle layer, and the number of variable density lattice units filled in the bottom layer is greater than or equal to the number of variable density lattice units filled in the middle layer.

[0018] Furthermore, it also includes a retaining ring that can hold the insulator in place, the retaining ring being detachably installed in the clamping area.

[0019] This invention provides another technical solution: a method for manufacturing a clamp, comprising the following steps:

[0020] Different stress zones of the fixture to be manufactured are obtained, and each stress zone is divided into a main load-bearing area and an auxiliary support area, wherein the main load-bearing area bears a large stress and the auxiliary support area bears a small stress.

[0021] Variable density lattice units of different densities are prepared for the main bearing area and the auxiliary support area to adjust the weight of the fixture to be manufactured according to the differences in stress areas.

[0022] A three-dimensional model of the variable density lattice unit filling fixture is established, and the density, number and layout of the variable density lattice units on the fixture are gradually adjusted in combination with the feedback data of stress-displacement field to obtain an optimized three-dimensional model.

[0023] Based on the optimized 3D model, an integrated mold is prepared for the production of the fixture;

[0024] A mechanical performance verification system was built to test the prepared fixture.

[0025] Furthermore, the variable density lattice units of different densities include solid variable density lattice units, partially centered variable density lattice units, and hollow variable density lattice units.

[0026] Compared with the prior art, the beneficial effects of the present invention are: by changing the volume of the support body within the frame, the density of the lattice unit can be changed, so that the load force borne by the lattice unit can also be varied. When applied to the fixture, lattice units of different densities can be filled according to different stress areas of the fixture, thereby greatly reducing the mass of the fixture while meeting the strength requirements of the fixture. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of an insulator clamp provided in an embodiment of the present invention;

[0028] Figure 2 for Figure 1 A schematic diagram of its vertical cross-section;

[0029] Figure 3 This is an exploded view of an insulator clamp provided in an embodiment of the present invention;

[0030] Figure 4 This is a schematic diagram of the structure of a variable density lattice unit of an insulator clamp provided in an embodiment of the present invention;

[0031] In the attached figures: 11-Upper body; 12-Lower body; 21-Upper retaining ring; 22-Lower retaining ring; 3-Rotating connecting device; 31-Pin; 32-Bolt; 33-Nut; 4-Variable density lattice unit; 41-Top layer; 42-Middle layer; 43-Bottom layer; 51-First connecting rod; 52-Second connecting rod; 53-Third connecting rod; 54-First arc-shaped rod; 55-Second arc-shaped rod; 56-Inner rod; 57-Base. Detailed Implementation

[0032] 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.

[0033] Please see Figure 4 This invention provides a variable-density lattice unit, including a frame and a support for load transfer. The support is disposed within the frame and occupies 0-100% of the space volume within the frame. In this embodiment, the density of the lattice unit is changed by altering the volume occupied by the support within the frame, thus making the load force borne by the lattice unit variable. When applied to an insulating fixture, lattice units of different densities can be filled according to different stress zones of the insulating fixture, significantly reducing the fixture's mass while meeting the fixture's strength requirements. Specifically, when the density of the lattice unit needs to be changed, the size of the support within the frame is adjusted. For example, if a solid lattice unit is required, the support completely occupies the space within the frame; if a hollow lattice unit is required, the support is eliminated. Of course, the extreme case of a hollow lattice unit is rare. Typically, for low-stress areas, the density can be set between 0.2 and 0.5, that is, occupying 20% ​​to 50% of the space within the frame, but hollow lattice units are not limited to this.

[0034] Please see Figure 4 To elaborate on the aforementioned support structure, the support structure includes a base 57 and at least two inner rods 56. One end of each inner rod 56 is connected to the frame, and the other end is connected to the base 57. The base 57 is fixed within the space of the frame by the inner rods 56. In this embodiment, the base can be designed at any position within the space of the frame, typically at the very center, such as... Figure 4As shown, four inner rods 56 can be used, with one end of each inner rod 56 connected to the four corners of the cubic frame structure. The other ends of the four inner rods 56 then work together to position the base in the center of the frame space. The inner rods 56 enable the continuous transmission of force, while the abutment 57, as the core of the node aggregation, can effectively transfer the load. In this way, the entire variable-density lattice unit 4 is structurally stable and can withstand different stresses depending on the strength of the support. The density can be changed by altering the size and material of the inner rods 56 and the abutment 57, thereby increasing the strength of the lattice unit.

[0035] Please see Figure 4 The frame includes several connecting rods, each forming a cubic structure. In this embodiment, the frame is preferably cubic, as this structure is more stable and facilitates the installation of supports within the interior space. The connecting rods constituting the frame can be straight rods, providing support in different directions depending on their orientation, thus ensuring structural stability. For example, the longitudinal third connecting rod 53 provides longitudinal support, while the transverse first connecting rod 51 and second connecting rod 52 provide transverse support. Alternatively, they can be curved rods, such as the first curved rod 54 and the second curved rod 55, which can alleviate stress concentration at the corners.

[0036] Please see Figure 4 The side length of the variable-density lattice unit 4 is inversely proportional to the stress function σ(x, y, z). In the high-stress region, the diameter of the rods and the connection area of ​​the variable-density lattice unit 4 increase with the stress gradient. The structural density distribution is controlled through a local recursive refinement mechanism to ensure that the minimum feature size of the lattice unit is not lower than the limit value of the LPBF process (≥0.5mm). Manufacturing constraints include: adding tapered support structures in areas with a droop angle of less than 45°, and controlling thermal deformation within the range of ≤0.5mm. The optimization objective function comprehensively considers design indicators such as minimizing structural mass, maximizing buckling strength, and maximizing energy absorption performance.

[0037] Please see Figures 1 to 4This invention provides a clamping fixture, including an upper body 11 and a lower body 12, which enclose a clamping area. It also includes the aforementioned variable-density lattice units 4, with a plurality of these units filling both the upper body 11 and the lower body 12. In this embodiment, by filling or integrating multiple variable-density lattice units 4 within the upper body 11 and lower body 12, localized reinforcement and lightweight load-bearing in critical areas can be achieved. Compared to traditional solid clamps, this design satisfies both strength and lightweight requirements. Specifically, by introducing a variable-density lattice unit 4 filling structure, the internal density is adjusted according to the clamp's stress distribution (solid filling in high-stress areas and hollow optimization in low-stress areas), achieving weight reduction (15%-30% weight reduction compared to traditional clamps) while ensuring strength. This lightweight design effectively reduces operator fatigue at heights and significantly improves replacement efficiency, making it particularly suitable for rapid insulator replacement in high-voltage transmission lines. Of course, in addition to being used as an insulator clamp in ultra-high voltage live-line work, this clamp can also be extended to fields such as power fittings and aerospace load-bearing structures that require optimized strength-to-weight ratio.

[0038] As an optimized solution for an embodiment of the present invention, please refer to Figures 1 to 4Both the upper body 11 and the lower body 12 have arched portions and connecting portions. The arched portions of the upper body 11 and the lower body 12 enclose the clamping area, and the connecting portions of the upper body 11 and the lower body 12 are connected. In this embodiment, the retaining ring can be further refined into arched portions and connecting portions. The upper body 11 and the lower body 12 are slightly different, but both contain these two components. The variable density lattice unit 4 in the above embodiment can be filled in the arched portions and connecting portions. Specifically, there are two integration methods. One method involves layering the arched portion, specifically designating the layer closest to the clamping area as the bottom layer 43, the middle layer as the middle layer 42, and the layer furthest from the clamping area as the top layer 41. That is, the arched portion is divided into a top layer 41, a middle layer 42, and a bottom layer 43 along the direction from the outer diameter to the inner diameter. The top layer 41, the middle layer 42, and the bottom layer 43 are all filled with variable density lattice units 4. Then, the number of variable density lattice units 4 filled in the top layer 41 is controlled to be less than the number of variable density lattice units 4 filled in the middle layer 42, and the number of variable density lattice units 4 filled in the bottom layer 43 is greater than or equal to the number of variable density lattice units 4 filled in the middle layer 42. The stress is greater closer to the clamping area, so a larger number of variable density lattice units 4 can be designed. The second method involves selecting the density of the filled variable density lattice units 4 according to the key areas. That is, the stress is greater closer to the middle area, so a higher density of variable density lattice units 4 can be filled in these areas to withstand greater stress. In addition, since the stress on the connecting part is relatively small, it can also be modified into a filling variable density lattice unit 4 to achieve the purpose of weight reduction.

[0039] As an optimized solution for an embodiment of the present invention, please refer to Figures 1 to 4 The clamp also includes a retaining ring for holding the insulator, which is detachably installed in the clamping area. In this embodiment, the retaining ring is designed to hold the insulator. Its detachable installation allows for the replacement of different retaining rings to hold different types of insulators, thus improving the versatility of this insulator clamp compared to traditional insulator clamps without retaining rings.

[0040] Please see Figures 1 to 4 The upper body 11 and lower body 12 are hinged together by a rotating connecting device 33, achieving an openable clamping structure. Both the upper body 11 and lower body 12 are made of AlMgScZr aluminum alloy, possessing excellent lightweight and corrosion resistance. Upper retaining ring 21 and lower retaining ring 22 are respectively provided in the contact area of ​​the upper body 11 and lower body 12 for positioning and clamping the insulator string. The retaining rings are made of TC4 titanium alloy, possessing high strength and wear resistance. The rotating connecting device 3, also made of TC4 titanium alloy, consists of a pin 31, bolt 32, and nut 33, facilitating assembly and quick disassembly.

[0041] Please see Figures 1 to 4 This invention provides a method for manufacturing a clamp, comprising the following steps: obtaining different stress zones of the clamp to be manufactured, and dividing each stress zone into a main load-bearing region and an auxiliary support region, wherein the main load-bearing region bears a large stress and the auxiliary support region bears a small stress; preparing variable-density lattice units 4 of different densities for the main load-bearing region and the auxiliary support region to adjust the weight of the clamp to be manufactured according to the differences in stress zones; establishing a three-dimensional model of the clamp filled with the variable-density lattice units 4, and gradually adjusting the density, number, and layout of the variable-density lattice units 4 on the clamp based on the feedback data of the stress-displacement field to obtain an optimized three-dimensional model; molding the clamp to be manufactured in one piece based on the optimized three-dimensional model; and building a mechanical performance verification system to test the manufactured clamp. In this embodiment, this method combines the actual stress characteristics and deformation response of the insulator clamp under typical working conditions to construct an adjustable density filling strategy for multi-stress regions, realizing the synergistic optimization of the structure in different functional regions. Guided by variable-density lattice unit 4 filling design, stress feedback control, and topology optimization results, the overall material distribution optimization is completed during the design phase, and the integrated forming of the clamp is achieved using metal additive manufacturing technology. This insulator clamp structure design not only significantly improves the clamp's comprehensive performance in terms of stress distribution, strength maintenance, stiffness control, and lightweight capabilities, but also greatly expands the structure's adaptability and enhances its manufacturability, demonstrating excellent engineering practicality and broad application prospects. Especially in the replacement of insulators for ultra-high voltage transmission lines, this invention can be widely applied to various complex operating scenarios, effectively reducing operational difficulty and alleviating the burden on workers, demonstrating significant technical advantages and practical application value.

[0042] Specifically, based on the finite element stress analysis results under typical working conditions, the fixture structure can be divided into a main load-bearing region (high stress region) and an auxiliary support region (low stress region). Based on this, variable-density lattice unit 4 is selected as the basic internal filling configuration. This lattice unit structure possesses excellent spatial recursive refinement capabilities, enabling dynamic adjustment of the node density distribution according to stress changes. To achieve regionally differentiated control of the material, a filling density function ρ(x, y, z)∈(0,1] is defined to guide the spatial distribution of lattice units. Specifically, the settings are as follows: in the high-stress region, ρ=1 is set, and solid material is used to ensure structural strength; in the medium-stress region, ρ=0.6~0.9 is set, and medium- to high-density lattice units are selected to balance performance and material usage; in the low-stress region, ρ=0.2~0.5 is set, and a low-density lattice structure is constructed to reduce weight and provide basic support. In this embodiment, Von-Mises stress field and deformation response data are extracted using finite element analysis and used as the function input for lattice unit density control, realizing a "solid-medium-dense-cavitation" regional allocation strategy. This design not only achieves efficient material utilization but also further reduces weight while ensuring load-bearing strength.

[0043] Then, based on the given density function ρ(x, y, z), the material distribution is mapped to the spatial distribution of the lattice unit, achieving stress-response-driven geometric configuration control. Specifically, high-density regions employ fully dense, small-feature-size lattice units to enhance local structural stiffness; medium-density regions use medium-scale lattice units to achieve a balance between mechanical performance and material efficiency; and low-density regions use large-scale hollow lattice units to effectively reduce mass load. For each gradient region, finite element models are established to systematically evaluate the maximum equivalent stress σmax and displacement field Δu distribution characteristics under various conditions, including clamping loads, eccentric shear loads, and dynamic vibrations. Through an iterative feedback mechanism, the lattice unit size parameters and spatial arrangement are continuously optimized to achieve the optimal lightweight design goal while ensuring structural load-bearing performance.

[0044] Next, a three-dimensional model of the lattice unit filling fixture was established, with overall dimensions set at 580mm × 231mm × 80mm. AlMgScZr aluminum alloy or TC4 titanium alloy, possessing excellent mechanical properties and additive manufacturing compatibility, were selected as the forming materials. Through 3-5 rounds of structural iteration optimization, combined with stress-displacement field feedback data, the regional density and layout of the lattice units were gradually adjusted to achieve synergistic optimization of quality and strength. The optimization objectives were: reducing the fixture structure mass by 15%-30%; maintaining or exceeding 85% of the original structure's strength level; and controlling the overall stiffness within the set range to ensure that safety margins and actual operational rigidity requirements are met. In this embodiment, additive manufacturing direct forming technology was adopted, avoiding the cumulative errors caused by multiple processes in traditional machining, ensuring dimensional accuracy, and supporting the rapid manufacturing of complex irregular structures.

[0045] Finally, additive manufacturing and performance verification were performed. Based on the optimized model, LPBF additive manufacturing was used for integrated forming. In the high-density solid regions, an interleaved scanning strategy was employed to improve density and deformation resistance; in the low-density lattice-filled regions, a unidirectional scanning strategy was used to control heat input and reduce residual stress. After forming, hot isostatic pressing was performed to further eliminate microcracks and residual stress fields, significantly improving fatigue performance and structural consistency. Finally, a servo-hydraulic loading system was built to verify the mechanical properties of the fabricated fixture, including static load response and dynamic load response tests, ensuring that the physical structure matches the simulated performance and fully meets the engineering application requirements for UHV insulator replacement operations.

[0046] As an optimized solution of this invention embodiment, when manufacturing the upper body 11 and lower body 12, a closed model containing a shell and lattice unit filling is constructed using 3D CAD modeling technology; in terms of support design, a combination of point support and conical support is set at the hanging part inside the lattice unit, and block support is used on the outside of the shell to improve the overall rigidity; AlMgScZr alloy powder is selected as the printing material; post-processing steps include support removal, hot isostatic pressing, machining and finishing of interface holes, and anodizing or sandblasting. When manufacturing the upper retaining ring 21 and lower retaining ring 22, TC4 titanium alloy rods are used and machined; the shape error is controlled within ±0.3mm, and the assembly gap is less than 0.1mm; the connection method is that the retaining ring is installed on the body through a positioning pin structure or a plug-in structure, with appropriate fit tolerances reserved. When manufacturing the rotating connection device 3, industrial-grade TC4 fasteners are selected for standard parts; non-standard parts (such as irregular pins) can be made of TC4 rods and finished by precision machining; key connection areas are strengthened by rolling or nitriding processes to improve fatigue life and loading / unloading durability.

[0047] As an optimized embodiment of the present invention, the variable-density lattice units 4 include solid variable-density lattice units 4, partially centered variable-density lattice units 4, and hollow variable-density lattice units 4. In this embodiment, by introducing lattice unit structures of different densities, the consumption of raw materials can be significantly reduced, thereby effectively reducing the overall manufacturing cost.

[0048] Thus, this invention solves the core problems of traditional clamps, such as material waste, unbalanced force distribution, low manufacturing efficiency, and weak adaptability. It can achieve:

[0049] 1. While maintaining the functional and external constraints of the fixture, the strength of key areas is improved and the overall weight is significantly reduced by optimizing the internal structural design;

[0050] 2. Based on the force field distribution under typical operating conditions, a stress-driven variable density lattice structure design is constructed to improve the precise control capability of the structural response;

[0051] 3. Achieve deep integration of structural design and metal additive manufacturing processes, and improve manufacturing efficiency and structural performance by integrally forming complex lattice structures and shell systems through additive manufacturing technology.

[0052] 4. Construct a complete closed-loop lightweight design process from virtual simulation modeling, lattice unit distribution optimization, physical manufacturing to structural testing and verification, to ensure the practicality, manufacturability and verifiability of the design.

[0053] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A clamping device, comprising an upper body and a lower body, wherein the upper body and the lower body enclose a clamping area, characterized in that: Both the upper and lower main bodies are filled with a plurality of variable-density lattice units. Each variable-density lattice unit includes a frame and a support for load transfer. The support is disposed within the frame and occupies 0 to 100% of the space volume within the frame. Both the upper body and the lower body have an arched portion and a connecting portion. The arched portions of the upper body and the lower body enclose the clamping area. The connecting portions of the upper body and the lower body are connected. The arched portion is divided into a top layer, a middle layer, and a bottom layer along the direction from the outer diameter to the inner diameter. The top layer, the middle layer, and the bottom layer are all filled with the variable density lattice units. The number of variable density lattice units filled in the top layer is less than the number of variable density lattice units filled in the middle layer, and the number of variable density lattice units filled in the bottom layer is greater than or equal to the number of variable density lattice units filled in the middle layer.

2. The clamp as described in claim 1, characterized in that: The support includes a base and at least two inner rods. One end of each inner rod is connected to the frame, and the other end is connected to the base. The base is fixed in the space within the frame by the inner rods.

3. The clamp as described in claim 1, characterized in that: The frame includes several connecting rods, each of which forms a cubic structure.

4. The clamp as described in claim 3, characterized in that: Some of the connecting rods are arc-shaped rods used to alleviate stress concentration at the corners.

5. The clamp as described in claim 1, characterized in that: It also includes a retaining ring that can hold an insulator in place, the retaining ring being detachably installed in the clamping area.

6. The method for manufacturing the clamp as described in claim 1, characterized in that, Includes the following steps: Different stress zones of the fixture to be manufactured are obtained, and each stress zone is divided into a main load-bearing area and an auxiliary support area, wherein the main load-bearing area bears a large stress and the auxiliary support area bears a small stress. Variable density lattice units of different densities are prepared for the main bearing area and the auxiliary support area to adjust the weight of the fixture to be manufactured according to the differences in stress areas. A three-dimensional model of the variable density lattice unit filling fixture is established, and the density, number and layout of the variable density lattice units on the fixture are gradually adjusted in combination with the feedback data of stress-displacement field to obtain an optimized three-dimensional model. Based on the optimized 3D model, an integrated mold is prepared for the production of the fixture; A mechanical performance verification system was built to test the prepared fixture.

7. The method for manufacturing the clamp as described in claim 6, characterized in that: Variable density lattice units of different densities include solid variable density lattice units, partially solid variable density lattice units, and hollow variable density lattice units.

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