Topological optimization method for hydraulic valve block of unsupported printing runner and hydraulic valve block

Abstract

The invention belongs to the technical field of hydraulic valve block preparation, and provides a topological optimization method for a hydraulic valve block of an unsupported printing runner and the hydraulic valve block, and the topological optimization method comprises the following steps: firstly, carrying out first topological optimization by taking pressure loss as a hydrodynamic optimization target, and determining a runner axis; secondly, carrying out second topological optimization according to manufacturing feasibility, and determining section parameters and shapes of the runners; and finally, carrying out third topological optimization by taking the structural strength and the function as optimization objectives, reconstructing a valve block redundant entity, and obtaining a final topological optimized hydraulic valve block entity model. Through optimization of flow channel axes and flow channel section parameters and shapes, the mode that a flow channel can only be formed by straight holes which are mutually orthogonal or form a certain angle is replaced, the requirement for the wall thickness of the valve block is guaranteed by taking pressure loss and manufacturing feasibility as targets, and a redundant entity of the valve block is reconstructed by taking structural strength and functional targets; the problems that due to the fact that the reserved safety wall is thick, the safety wall is heavy, and a large number of redundant entities which are not effectively utilized exist in the safety wall are solved.

Description

Technical Field

[0001] This invention belongs to the field of hydraulic valve block manufacturing technology, and particularly relates to a topology optimization method for hydraulic valve blocks with unsupported printed flow channels and a hydraulic valve block. Background Technology

[0002] Traditional valve blocks are generally manufactured using casting or machining processes, primarily using cast iron and aluminum alloys. Their internal flow channels are typically vertically intersecting right-angled channels. This design, constrained by manufacturing processes, results in inherent defects in the flow channel layout. In recent years, topology optimization and additive manufacturing technologies have provided new approaches to forming complex flow channels, and their process characteristics theoretically support the integral manufacturing of arbitrary three-dimensional flow channel structures. However, existing topology optimization algorithms are mostly based on single-field optimization, making it difficult to accurately characterize the multi-physics coupling effects under actual hydraulic valve block operating conditions, and failing to fully utilize the geometric freedom advantages of additive manufacturing.

[0003] While traditional design methods achieve goals such as reduced pressure loss and weight reduction, they fail to incorporate relevant strategies in the early stages of topology optimization iterations, thus undermining the potential for topology weight reduction. Specifically, traditional design methods require compromises in flow channel morphology due to drilling process limitations. Flow channels are essentially limited to orthogonal or angled straight holes, resulting in unavoidable right-angle turns or T-junctions at spatial intersections, leading to high pressure loss and low efficiency. Furthermore, to prevent the drill bit from penetrating adjacent flow channels or the valve block's outer wall during drilling, traditional designs must reserve thick safety walls. Consequently, valve blocks are typically designed as bulky cubes or large solid bodies, containing a large amount of unused redundant material. For complex, large-angle flow channels, additional supports are needed to ensure molding accuracy and surface quality, hindering the application of additive manufacturing in the hydraulic field. Summary of the Invention

[0004] To address the aforementioned problems, this invention proposes a topology optimization method for a hydraulic valve block with unsupported printed flow channels and a hydraulic valve block itself. This invention replaces the previous method of flow channels being composed only of mutually orthogonal or angled straight holes by optimizing the flow channel axis, cross-sectional parameters, and shape. By prioritizing pressure loss and manufacturing feasibility, the invention ensures the required valve block wall thickness. Furthermore, by reconstructing the redundant entities of the valve block based on structural strength and functional objectives, this invention solves the problem of bulkiness caused by reserved safety wall thickness and addresses the issue of a large number of ineffectively utilized redundant entities within the valve block.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution: In a first aspect, the present invention provides a method for topology optimization of a hydraulic valve block with unsupported printed flow channels, comprising: Obtain the initial geometric features of the valve block; discretize the initial geometric features of the valve block to determine the relative positions between relevant physical features; All flow channel axes are extracted from relevant physical features. The first topology optimization is performed with pressure loss as the fluid dynamics optimization objective to determine the flow channel axes. Using the channel axis after the first topology optimization as the sweep path, a second topology optimization is performed based on manufacturing feasibility to determine the channel cross-sectional parameters and shape. Based on the load spectrum of the hydraulic valve block, a third topology optimization is performed with structural strength and function as optimization objectives. The redundant entity of the valve block is reconstructed to obtain the final topology-optimized hydraulic valve block entity model.

[0006] Furthermore, the relevant physical features include valve block flow channels, valve seat holes, process holes, mounting holes, and redundant physical structures.

[0007] Furthermore, the first topology optimization includes: designing the flow channel axis as a smooth cubic B-spline curve; and using a gradient descent optimization method to adjust the curve coordinates with the goal of minimizing pressure loss along the flow path.

[0008] Furthermore, after the first topology optimization is completed, the minimum Euclidean distance between the spatial relative positions of the flow channel axes is calculated. If the minimum Euclidean distance at any position is greater than the preset safety margin, the second topology optimization is performed; otherwise, the first topology optimization is continued.

[0009] Furthermore, the second topology optimization includes: determining the printing overhang angle based on the angle between the printing direction and the channel axis; the channel cross-section at an overhang angle < 45° is circular, and the channel cross-section at an overhang angle of 90° is teardrop-shaped.

[0010] Furthermore, multiple channels with inner diameters smaller than preset values ​​are set in parallel at the redundant solids on the inner wall of the optimized flow channel.

[0011] Furthermore, after the second topology optimization is completed, it is determined whether the minimum wall thickness between the flow channels is greater than the preset value. If it is, the third topology optimization is performed; otherwise, the first and second topology optimizations are performed.

[0012] Furthermore, the third topology optimization includes: setting the valve block flow channel, valve seat hole and mounting hole as unchangeable non-design areas, and the remaining redundant entities of the valve block as design areas that can be topologically optimized, and establishing a three-dimensional solid finite element model of the valve block; according to the property parameters of the valve body material, by setting the constraint condition of maximizing the stiffness of the anisotropic material, iteratively calculating the redundant entities of the valve block.

[0013] Furthermore, after the third topology optimization is completed, the system's maximum working pressure, bolt preload, and external vibration excitation conditions are simulated according to the valve block's working load spectrum. Functional tests are conducted through structural mechanics simulation and interference checks to determine whether the valve block meets the usage requirements. If it does, the optimization is completed; otherwise, the valve block's physical structure is re-optimized in the topology.

[0014] Secondly, the present invention also provides a hydraulic valve block without support printing channels, which is optimized by the hydraulic valve block topology optimization method without support printing channels as described in the first aspect.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention first performs a first topology optimization with pressure loss as the fluid dynamics optimization objective to determine the flow channel axis; then, a second topology optimization is performed based on manufacturing feasibility to determine the flow channel cross-sectional parameters and shape; finally, a third topology optimization is performed with structural strength and function as optimization objectives to reconstruct the redundant entity of the valve block and obtain the final topology-optimized hydraulic valve block entity model; by optimizing the flow channel axis and flow channel cross-sectional parameters and shape, the method of flow channels being composed only of mutually orthogonal or angled straight holes is replaced; by targeting pressure loss and manufacturing feasibility, the valve block wall thickness requirements are guaranteed; and the redundant entity of the valve block is reconstructed with structural strength and function objectives, solving the problem of bulkiness caused by reserved safety wall thickness and the problem of a large number of ineffectively utilized redundant entities inside the valve block.

[0016] 2. This invention reconstructs the flow channel axis, cross-sectional shape, and redundant entity of the valve block in sequence, and determines the optimization objective function through multi-physics coupling simulation, so as to systematically achieve progressive optimization of the flow stability, structural stiffness and additive formability of the high-performance hydraulic valve block.

[0017] 3. Traditional techniques simply use diameter as the threshold for optimization, which changes the cross-sectional shape of some unnecessary optimized flow channels. Based on this, in addition to diameter, this invention introduces overhang angle to determine whether to use a teardrop-shaped flow channel, which can reduce the decrease in fluid dynamics characteristics caused by the reduction in cross-sectional area of ​​the flow channel after printing. Attached Figure Description

[0018] The accompanying drawings, which form part of this embodiment, are used to provide a further understanding of this embodiment. The illustrative embodiments and their descriptions are used to explain this embodiment and do not constitute an improper limitation of this embodiment.

[0019] Figure 1 This is a schematic diagram of the hydraulic valve block topology optimization process according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the hydraulic valve block topology optimization process in Embodiment 1 of the present invention; Figure 3 This is a schematic diagram of the flow channel axis in Embodiment 1 of the present invention; Figure 4 This is a schematic diagram of the flow channel after the first topology optimization in Embodiment 1 of the present invention; Figure 5 This is a schematic diagram of the flow channel cross-section of the hydraulic valve block in Embodiment 1 of the present invention, wherein (a) is a schematic diagram of the circular flow channel cross-section, and (b) is a schematic diagram of the water droplet flow channel cross-section. Figure 6 This is a structural diagram of the valve block after the third topology optimization in Embodiment 1 of the present invention; Among them, 1. First valve seat hole; 2. Second valve seat hole; 3. Third valve seat hole; 4. Fourth valve seat hole; 5. Fifth valve seat hole; 6. First process hole; 7. Second process hole; 8. Third process hole; 9. First flow channel; 10. Second flow channel; 11. Third flow channel; 12. Fourth flow channel; 13. Circular flow channel cross section; 14. Water droplet flow channel cross section. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0022] As the core control unit of a hydraulic system, the hydraulic valve block undertakes the critical functions of flow distribution, pressure regulation, and directional control. Traditional valve blocks are generally manufactured using casting or machining processes, primarily using cast iron and aluminum alloys. Their internal flow channels are typically vertically intersecting right-angled channel structures. This design, constrained by manufacturing processes, results in the following inherent defects in the flow channel layout: right-angle bends induce turbulence effects, causing significant pressure loss; redundant material accumulation leads to excessive valve block volume; and multi-body assembly introduces the risk of leakage at the sealing interface. As hydraulic systems evolve towards higher pressure and integration, traditional structures can no longer meet the demands for compact space layouts and high energy efficiency.

[0023] In recent years, topology optimization and additive manufacturing technologies have provided new approaches for the forming of complex flow channels, and their process characteristics theoretically support the integral manufacturing of arbitrary three-dimensional flow channel structures. However, existing topology optimization algorithms are mostly based on single-field optimization, which makes it difficult to accurately characterize the multi-physics coupling effect under actual working conditions of hydraulic valve blocks, and therefore cannot fully utilize the geometric degrees of freedom advantages of additive manufacturing.

[0024] As a key basic component integrating control elements in a hydraulic system, the performance of the hydraulic valve block directly affects the system's efficiency, reliability, and spatial layout. As described in the background section, traditional design methods require setting the flow channel shape within the constraints of drilling processes. The flow channels are essentially limited to mutually orthogonal or angled straight holes, resulting in unavoidable right-angle turns or T-junctions at spatial intersections, leading to high pressure loss and low efficiency. Furthermore, to ensure the drill bit doesn't penetrate adjacent flow channels or the valve block's outer wall during drilling, traditional designs must reserve a thick safety wall thickness. Therefore, valve blocks are typically designed as bulky cubes or large solid bodies, containing a large amount of unused redundant material. Currently, lightweight design methods for hydraulic valve blocks lack systematic structural optimization techniques. For complex, large-angle flow channels, additional supports are needed to ensure molding accuracy and surface quality, hindering the application of additive manufacturing in the hydraulic field.

[0025] Based on this, the present invention addresses the inherent shortcomings of traditional hydraulic valve blocks in terms of fluid performance, structural efficiency, lightweight design, manufacturing complexity, and adaptability. Figure 1 As shown, a topology optimization method for a hydraulic valve block with unsupported printed flow channels is provided. The method adopts a three-stage topology optimization approach and obtains the optimal design method for the hydraulic valve block through a collaborative design strategy of fluid dynamics optimization, manufacturing constraint driving, and structural performance reconstruction.

[0026] The method employs step-by-step topology optimization constrained by the hydraulic valve block's function and additive manufacturing process. It sequentially reconstructs the flow channel axis, cross-sectional shape, and redundant valve block entities. The optimization objective function is determined through multiphysics coupled simulation, systematically achieving progressive optimization of the flow stability, structural stiffness, and additive formability of the high-performance hydraulic valve block. The method includes the following steps: S1. Define the load spectrum of the hydraulic valve block, input the initial valve block geometric model, discretize the initial valve block geometric features, and define the spatial relative positions between the relevant physical features such as the valve block flow channel, valve seat hole, process hole, mounting hole and redundant solid structure.

[0027] S2. Extract all flow channel axes individually, and perform the first topology optimization with pressure loss as the fluid dynamics optimization objective to determine the flow channel axes.

[0028] Topology optimization is performed on the flow channels of the hydraulic valve block. The flow channels on the hydraulic valve block can be divided into two categories: the first category is the functional flow channel connecting the valve seat hole port, and the second category is the process flow channel that runs through the functional flow channel. To ensure that the position of the control valve mounting port is not changed after the hydraulic valve block is optimized, the overall installation method of the valve block is the same as that of the initial valve block. Based on the discretized geometric features of the valve block, the relative positions of the valve seat hole and the flow channel space of the valve block are determined and not changed. Only the topology optimization is performed on the functional flow channel connecting the valve seat hole port. The process holes and corresponding process flow channels on the valve block used to run through the flow channel are removed to prevent the generation of redundant solid features.

[0029] The first topology optimization preserves the valve seat hole and valve block flow channel, and the spatial relative position of the valve seat hole is not changed. The flow channel axis is optimized according to the objective function. After each optimization, the flow channel entity cross interference check must be performed to ensure that there is no cross interference before proceeding to the next step.

[0030] In some embodiments, the dynamic evolution of the flow channel axis is realized by establishing the fluid-structure interaction dynamic equation of the flow channel and solving the extrema of the generalized function of the equation. Compared with purely data-driven empirical regression methods, this method provides a mathematical guarantee for the continuity of the physical field.

[0031] S2.1 Topology optimization of the valve block flow channel is divided into optimization of the flow channel axis and optimization of the flow channel cross-section. As the main guiding structure for fluid flow, the geometry of the flow channel axis directly affects key fluid dynamic parameters such as flow separation, pressure loss, and turbulence intensity. Optionally, the curvature of the axis can be optimized by parametric cubic B-spline curves, achieving asymptotic changes in the radius of curvature. During optimization, a pressure loss objective function is established, and a gradient descent optimization method is used to adjust the curve coordinates with the goal of minimizing pressure loss along the flow path. Multi-condition optimization iterations are then performed using fluid simulation software. Topology optimization of the flow channel axis avoids right-angle turns or T-shaped intersections formed by traditional manufacturing processes, preventing severe turbulence, vortices, and flow separation at corners, thus improving system efficiency.

[0032] Optionally, the flow channel axis is constructed using a parametric cubic B-spline curve. Based on physical constraints such as curvature continuity and minimum turning radius, the fluid velocity gradient field is extracted using the Navier-Stokes equations to correct the curvature of the cubic B-spline curve. The control points of the cubic B-spline are iteratively optimized using the gradient descent method to ensure that the rate of curvature change meets manufacturing requirements. Compared with conventional techniques, this embodiment uses local shape approximation to replace static spline curves, which can synergistically optimize the multi-objective optimization problem of flow channel performance and manufacturing feasibility.

[0033] The pressure loss function in this embodiment, based on the fluid-structure interaction dynamics equation, can realize the pressure loss gradient of the flow field, which reacts on the solid domain and drives the flow channel shape to evolve towards a lower resistance direction.

[0034] ; in, Let the pressure loss objective function be... For fluid dynamic viscosity, For the velocity gradient tensor, For the fluid domain volume, For the flow channel pressure difference, This represents the boundary of the fluid domain.

[0035] The flow channel axis is designed as a gentle cubic B-spline curve. The main objective of flow channel axis optimization is to minimize the pressure loss along the flow path, and the pressure loss of the flow channel is analyzed through fluid simulation software or methods.

[0036] S2.2 After the flow channel axis topology is completed, the spatial intersection of the axis needs to be checked by the geometric interference verification mechanism. The safety margin is determined based on the original valve block flow channel diameter. The minimum Euclidean distance between the spatial relative positions of the flow channel axis is calculated. If the minimum Euclidean distance at any position is greater than the safety margin, the process can proceed to step S3. Otherwise, return to step S2 to re-optimize the flow channel axis topology.

[0037] S3. Using the channel axis after the first topology optimization as the sweep path, perform a second topology optimization based on manufacturing feasibility to determine the channel cross-sectional parameters and shape.

[0038] S3.1 Before the second topology optimization, the printing direction of the valve block must be determined. The printing overhang angle is determined according to the angle between the printing direction and the flow channel axis. The flow channel cross section with an overhang angle < 45° is circular, and the flow channel cross section with an overhang angle of 90° is teardrop-shaped. The intermediate transition area is optimized with an overhang angle < 45° as the objective function. Parallel micro-channels are set at the redundant solids on the inner wall of the optimized flow channel to prevent the flow channel cross section from decreasing and the weight from increasing.

[0039] Specifically, after completing the topology optimization of the flow channel axis, the flow channel cross-section is then optimized according to manufacturing requirements. Before cross-section optimization, the valve block printing direction needs to be determined. Parameters are discretely sampled along the flow channel axis, and the angle between the tangent direction of the axis at each point and the printing direction is calculated. The flow channel cross-section is then classified based on the angle value. Specifically, areas with an overhang angle <45° are classified as the bottom overhang zone, where the flow channel cross-section remains unchanged, using the initial circular cross-section. Areas with an overhang angle of 90° are classified as the high overhang zone; to prevent collapse during printing, a different design is adopted. Figure 5The teardrop-shaped cross-section shown has a transition zone defined by overhang angles between 45° and 90°. To ensure continuity in cross-sectional position, sectional plane, and curvature, a surface lofting algorithm is used, with the cross-sectional curve and printing direction angle <45° as the objective function for transition surface fitting. Simultaneously, to prevent increased flow velocity due to reduced flow channel cross-section and the increase in redundant entities after flow channel optimization, and to minimize the impact of flow channel cross-section optimization on valve block performance, parallel micro-channels with an inner diameter <8mm are set at the redundant entities on the inner wall of the optimized flow channel, ensuring that the channels can be printed without support.

[0040] It should be noted that traditional techniques use diameter to determine whether to use a teardrop-shaped flow channel. Flow channels smaller than 8mm can be printed at any overhang angle. However, flow channels with an overhang angle <45° can be printed smoothly even if the diameter is greater than 8mm without changing the cross-sectional shape. Therefore, simply using diameter as the threshold for optimization will change the cross-sectional shape of some flow channels that do not require optimization. Based on this, this embodiment introduces an overhang angle, in addition to diameter, to determine whether to use a teardrop-shaped flow channel. This can reduce the decrease in hydrodynamic characteristics caused by the reduction in the cross-sectional area of ​​the flow channel after printing.

[0041] S3.2 After the flow channel cross-section topology optimization is completed, the minimum wall thickness of the flow channel must be checked to ensure that the flow channel wall thickness is not less than the preset value and can meet the working pressure requirements before proceeding to the next step.

[0042] Specifically, to prevent the hydraulic valve block from being punctured during use, after the flow channel cross-section is fitted, the distance between the fitted surfaces of the flow channels should be checked according to the load spectrum of the hydraulic valve block. Generally, the minimum wall thickness between flow channels should not be less than 5mm, and it can be multiplied by the corresponding safety factor based on the highest working pressure in the flow channel. If the distance between all fitted surfaces of the flow channels is greater than the safe wall thickness, then step S4 can be performed; otherwise, return to steps S2 and S3 to re-optimize the flow channel axis and flow channel cross-section.

[0043] S4. Based on the load spectrum of the hydraulic valve block, a third topology optimization is performed with structural strength and function as optimization objectives. The redundant entity of the valve block is reconstructed to obtain the final topology-optimized hydraulic valve block entity model.

[0044] S4.1 The third topology optimization reconstructs redundant entities based on the functional and manufacturing constraints of the hydraulic valve block. The solid surface adopts a smooth arc surface to reduce the existence of stress concentration structures.

[0045] Specifically, the completed flow channels, valve seat holes, and mounting holes are designated as unchangeable non-design regions, while the remaining redundant valve block entities are treated as topology-optimizable design domains. A three-dimensional solid finite element model of the valve block is established, and the elastic modulus, Poisson's ratio, yield strength, and other property parameters of the valve body material are input. Iterative calculations are performed on the redundant valve block entities by setting constraints to maximize the stiffness of anisotropic materials. Iteration stops and the optimization results are output when the structural stress concentration factor falls below a safe value. During the optimization process, a smooth-transition irregular structure is generated using surface fitting technology. Reinforcing ribs are added to the pressure-bearing wall surface, and an arc-shaped transition structure for stress dispersion is constructed in the intersecting channel region to prevent stress concentration.

[0046] When stress concentration in the valve block exceeds the preset safety value, a third topology optimization is performed. It's important to note that the location of stress concentration exceeding the preset safety value varies. If only the location with stress concentration exceeding the preset safety value is optimized during the third topology optimization, it can easily lead to increased stress in other locations. Therefore, optimization should be limited to critical locations. When stress concentration exceeds the preset safety value at the connection between the first flow channel 9, the second flow channel 10, the third flow channel 11, or the fourth flow channel 12 and the first valve seat hole 1, in order not to affect the overall fluid performance, only the connection is reinforced, such as by adding weld points or increasing the external wall thickness of the flow channel connection. If the stress concentration is lower than the safety value after reinforcement, the process iterates and outputs the optimization result; otherwise, the optimization continues. If the number of optimizations exceeds the preset number, it means that the reinforcement method cannot meet the requirements, and the direction, wall thickness, etc. of the first flow channel 9, the second flow channel 10, the third flow channel 11, or the fourth flow channel 12 are then considered for optimization until the stress concentration is lower than the safety value after reinforcement.

[0047] When the stress concentration exceeds the preset safety value at the middle position of the first flow channel 9, the second flow channel 10, the third flow channel 11, or the fourth flow channel 12, which is prone to stress concentration, in order not to affect the overall fluid performance, priority should be given to optimizing the wall thickness and other parameters of the first flow channel 9, the second flow channel 10, the third flow channel 11, or the fourth flow channel 12. If the stress concentration is lower than the safe value after optimization, iterate and output the optimization result; otherwise, continue to optimize. If the number of optimizations exceeds the preset number, it means that the wall thickness optimization method cannot meet the requirements, and then optimize the corresponding flow channel direction until the stress concentration is lower than the safe value after reinforcement.

[0048] S4.2 After the redundant entity topology optimization is completed, mechanical simulation analysis and functional verification must be performed against the hydraulic valve block load spectrum to ensure that the optimized valve block can meet the usage requirements before proceeding to the next step.

[0049] Specifically, after the hydraulic valve block optimization is completed in step S4, simulations of typical working conditions such as the system's maximum working pressure, bolt preload, and external vibration excitation need to be performed according to the valve block's working load spectrum. Functional tests are then conducted through structural mechanics simulation and interference checks to determine if the valve block meets the usage requirements. If the tests fail, the process must return to step S4 to perform topology optimization on the valve block's physical structure again.

[0050] S5. Based on the solid model of the hydraulic valve block, laser powder bed melting technology is used to complete the printing process.

[0051] Optionally, before preparing the solid model of the hydraulic valve block, the printing parameters need to be determined according to the material of the hydraulic valve block, and supports and slicing processes are added in sequence. Finally, the model is prepared using laser powder bed melting technology.

[0052] Specifically, after the functional test in step S4 is completed, step S5 uses laser powder bed melting technology to prepare the valve block entity. Before printing, the printing parameters need to be determined based on experience, and supports need to be added to the external solid structure with a droop angle greater than 45° in sequence. The valve block entity model after adding supports is then sliced.

[0053] The present invention also provides a hydraulic valve block with unsupported printed flow channels, which is obtained by the hydraulic valve block topology optimization method with unsupported printed flow channels of the present invention.

[0054] This invention optimizes the flow channel axis shape, cross-sectional shape, and redundant solid structure sequentially and precisely through multi-objective and multi-step collaborative optimization. This effectively reduces the pressure loss and mass of the valve block along the flow path and ensures the self-supporting manufacturability and pressure-bearing reliability of the flow channel. This progressive and goal-oriented optimization strategy eliminates the dilemma of not being able to fully unify fluid, manufacturing, and structural objectives in traditional valve block design, and achieves the optimal solution for overall performance.

[0055] Driven by optimization of three physical objectives—fluid performance, manufacturing constraints, and structural strength—this invention can ultimately output a solid model that can be directly used in laser powder bed melting (LPBF) equipment. By combining fluid simulation, mechanical simulation, and constraint checks, a high-quality conversion from model to solid is ensured.

[0056] Example 1: This embodiment provides a topology optimization method for a hydraulic valve block with unsupported printed flow channels, and will be specifically illustrated using the design and manufacturing method of a hydraulic valve block in a specific embodiment.

[0057] like Figure 2As shown, a hydraulic valve block designed and manufactured using traditional machining methods includes a first valve seat hole 1, a second valve seat hole 2, a third valve seat hole 3, a fourth valve seat hole 4, a fifth valve seat hole 5, a first process hole 6, a second process hole 7, and a third process hole 8. The valve seat holes are used to install the control valve, and the process holes are machining holes remaining on the valve block surface after machining the process flow channels; they are generally plugged using plugs. The optimization and manufacturing method of the hydraulic valve block in this embodiment includes: S1. Define the load spectrum of the hydraulic valve block and the typical working conditions of the valve block. Discretize the valve block features and define the relative spatial positions between the valve block features.

[0058] S2, such as Figure 3 As shown, the valve seat hole and process hole features are preserved, the flow channel axis is extracted, and the location and quantity of right-angle flow channels and T-shaped flow channels are analyzed.

[0059] Remove the process holes and corresponding flow channels, connect each valve seat port through a cubic B-spline curve according to the through relationship, and perform topology optimization on the flow channel axis to minimize pressure loss.

[0060] After the flow channel axis is optimized, the overall layout is as follows: Figure 4 As shown, the middle port of the first valve seat hole 1 is connected to the bottom ports of the second valve seat hole 2, the third valve seat hole 3 and the fourth valve seat hole 4 respectively to form the third flow channel 11, the fourth flow channel 12 and the first flow channel 9; the bottom port of the first valve seat hole 1 and the bottom port of the fifth valve seat hole 5 are connected to form the second flow channel 10.

[0061] Using the original valve block diameter as a safety margin, the spatial intersectingity of the first flow channel 9, the second flow channel 10, the third flow channel 11, and the fourth flow channel 12 is tested. The distance between flow channels that do not enter the same valve seat port should be less than the safety margin; otherwise, the flow channel axis is re-optimized.

[0062] Output the optimized flow channel axis features.

[0063] S3. Calculate the diameter of the flow channel cross-section. For flow channels with a diameter < 8mm, no support is needed for printing; step S3 can be skipped, and all steps can proceed as follows. Figure 5 The circular flow channel section 13 shown in the figure; for flow channels with a diameter ≥ 8 mm, flow channel section topology optimization is still required to achieve supportless printing.

[0064] The 3D printing direction is determined to be the axis direction of the first valve seat hole 1, and the angle between the axis of each flow channel after optimization and the printing direction is calculated as the overhang angle.

[0065] The optimization targets are divided according to the overhang angle value, and the axial region with an overhang angle < 45° is used as follows: Figure 5 The circular flow channel section 13 shown; the axial region with a 90° overhang angle adopts the following... Figure 5The water droplet flow channel section 14 shown requires that the angle between the straight line on the upper side of the teardrop-shaped section and the printing direction be less than 45°. The middle area is a transition area, and the transition surface is fitted using a surface lofting algorithm with the cross-sectional curve and the printing direction being less than 45° as the objective function. Simultaneously, circular channels with a diameter of less than 8mm are provided in the flow channel of the water droplet flow channel section 14, forming parallel channels with the teardrop-shaped channels to reduce the impact of flow channel section optimization on valve block performance.

[0066] The minimum wall thickness is determined based on the operating pressure of the valve block. The distance between the inner walls of the optimized flow channel should be greater than the minimum wall thickness; otherwise, the flow channel axis should be optimized again.

[0067] Output the optimized flow channel entity features.

[0068] S4. Set the valve seat hole obtained in step S1 and the flow channel obtained in step S3 as unchangeable non-design areas, and establish a parametric three-dimensional model based on the actual size of the original valve block. Use Boolean operations to retain redundant entities as design domains.

[0069] Based on the valve block load spectrum, input the elastic modulus, Poisson's ratio, yield strength and other property parameters of the valve body material.

[0070] A volume reduction target is set, and the redundant solid is geometrically reconstructed under the constraint of maximizing anisotropic stiffness. For walls subjected to pulsating pressure, stiffeners are arranged along the principal stress traces, and a double curvature transition structure is adopted in the intersecting channel area to ensure the continuity of surface curvature.

[0071] Perform multiphysics simulation on the valve block after topology optimization according to the typical working conditions of the valve block in step S1 to ensure that the valve block can meet the usage requirements; otherwise, re-optimize the topology of the redundant entities of the valve block.

[0072] Output the optimized solid model of the valve block.

[0073] S5. To ensure the assembly accuracy between the valve block and other components, machining allowances are added to features with high machining accuracy requirements, such as valve seat holes.

[0074] Based on the printing direction determined in step S3, add supports to the protruding parts, inclined surfaces and end faces of the valve block with an overhang angle >45°, and select columnar or grid-shaped supports according to the position differences.

[0075] After adding the supporting valve block solid model using slicing software, slice the model into a series of horizontal layers according to the set layer thickness.

[0076] The valve block was prepared using laser powder bed melting technology.

[0077] The key features of the valve block and the support removal are completed using CNC machine tools.

[0078] Figure 6 As shown, the topology-optimized hydraulic valve block mechanism manufactured using the method of this embodiment minimizes the weight of the hydraulic valve block, improves the lightweight level of the hydraulic valve block, reduces flow channel pressure loss, and improves flow efficiency.

[0079] The above description is merely a preferred embodiment of this practice and is not intended to limit the scope of this practice. Various modifications and variations can be made to this practice by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this practice should be included within the protection scope of this practice.

Claims

1. A method for topology optimization of a hydraulic valve block with unsupported printed flow channels, characterized in that, include: Obtain the initial valve block geometry; Discretize the initial valve block geometry to determine the relative positions between relevant physical features; All flow channel axes are extracted from relevant physical features. The first topology optimization is performed with pressure loss as the fluid dynamics optimization objective to determine the flow channel axes. Using the channel axis after the first topology optimization as the sweep path, a second topology optimization is performed based on manufacturing feasibility to determine the channel cross-sectional parameters and shape. Based on the load spectrum of the hydraulic valve block, a third topology optimization is performed with structural strength and function as optimization objectives. The redundant entity of the valve block is reconstructed to obtain the final topology-optimized hydraulic valve block entity model.

2. The method for topology optimization of a hydraulic valve block with unsupported printed flow channels as described in claim 1, characterized in that, The relevant physical features include valve block flow channels, valve seat holes, process holes, mounting holes, and redundant physical structures.

3. The method for topology optimization of a hydraulic valve block with unsupported printed flow channels as described in claim 1, characterized in that, The first topology optimization includes: designing the flow channel axis as a smooth cubic B-spline curve; and using the gradient descent optimization method to adjust the curve coordinates with the goal of minimizing pressure loss along the flow path.

4. The method for topology optimization of a hydraulic valve block with unsupported printed flow channels as described in claim 3, characterized in that, After the first topology optimization is completed, the minimum Euclidean distance between the spatial relative positions of the flow channel axes is calculated. If the minimum Euclidean distance at any position is greater than the preset safety margin, the second topology optimization is performed; otherwise, the first topology optimization is continued.

5. The method for topology optimization of a hydraulic valve block with unsupported printed flow channels as described in claim 1, characterized in that, The second topology optimization includes: determining the printing overhang angle based on the angle between the printing direction and the channel axis; the channel cross-section at an overhang angle < 45° is circular, and the channel cross-section at an overhang angle of 90° is teardrop-shaped.

6. The method for topology optimization of a hydraulic valve block with unsupported printed flow channels as described in claim 5, characterized in that, In the redundant solid area of ​​the optimized flow channel inner wall, multiple channels with an inner diameter smaller than the preset value are set in parallel.

7. The method for topology optimization of a hydraulic valve block with unsupported printed flow channels as described in claim 5, characterized in that, After the second topology optimization is completed, it is determined whether the minimum wall thickness between the flow channels is greater than the preset value. If it is, the third topology optimization is performed; otherwise, the first and second topology optimizations are performed.

8. The method for topology optimization of a hydraulic valve block with unsupported printed flow channels as described in claim 1, characterized in that, The third topology optimization includes: setting the valve block flow channel, valve seat hole and mounting hole as unchangeable non-design areas, and the remaining redundant entities of the valve block as design areas that can be topologically optimized, and establishing a three-dimensional solid finite element model of the valve block; according to the property parameters of the valve body material, iterative calculations are performed on the redundant entities of the valve block by setting constraints to maximize the stiffness of anisotropic materials.

9. The method for topology optimization of a hydraulic valve block with unsupported printed flow channels as described in claim 8, characterized in that, After the third topology optimization is completed, the system's maximum working pressure, bolt preload, and external vibration excitation conditions are simulated according to the valve block's working load spectrum. Functional tests are conducted through structural mechanics simulation and interference checks to determine whether the valve block meets the usage requirements. If it does, the optimization is completed; otherwise, the valve block's physical structure is re-optimized in the topology.

10. A hydraulic valve block with unsupported printed flow channels, characterized in that, The topology of the hydraulic valve block with unsupported printed flow channels as described in any one of claims 1-9 was optimized.

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