Production method of large-caliber multichannel ultrasonic water meter shell fused with stress regulation and control

Abstract

The invention relates to the technical field of precision manufacturing, and discloses a large-caliber multichannel ultrasonic water meter shell production method fusing stress regulation and control, which comprises the following steps: acquiring a target stress field of a water meter shell workpiece; acquiring an initial actual stress field of the workpiece; based on the difference between the target stress field and the actual stress field, performing closed-loop iterative local energy application on the workpiece so as to drive the actual stress field to approach the target stress field until the difference is smaller than a preset threshold value; and carrying out precision machining on the workpiece after the stress field regulation and control is completed to obtain a finished watchcase. According to the method, an ideal target stress field of the water meter shell is designed in advance through a performance-driven topological optimization algorithm, and compared with the prior art that residual stress is generally reduced or homogenized by means of annealing or vibration aging and the like, the residual stress is reduced or homogenized; the technical bottleneck that specific beneficial stress cannot be accurately generated in different areas according to product performance requirements is solved.

Description

Technical Field

[0001] The present invention relates to the field of precision manufacturing technology, and in particular to a method for producing a large-caliber multi-channel ultrasonic water meter case integrating stress regulation. Background Art

[0002] Large-diameter, multi-channel ultrasonic water meters, core equipment in modern fluid measurement, are crucial for long-term measurement accuracy and stability. These meters are typically cast from materials such as ductile iron, and their complex internal structure includes ultrasonic signal propagation channels that require extremely high dimensional and positional accuracy.

[0003] During the manufacturing process of watch cases, from the casting stage where high-temperature molten iron solidifies and cools to the subsequent machining to remove excess material, complex residual stresses are inevitably introduced and accumulated within the workpiece. The presence of these residual stresses has become a recognized technical challenge that affects the ultimate performance and long-term reliability of these precision instruments.

[0004] To address this issue, existing technologies typically employ stress relief measures. For example, processes such as bulk annealing or vibration aging are commonly used. However, the inventors of the present invention have discovered through research and practice that these existing technologies suffer from a series of profound and interrelated deficiencies.

[0005] First, existing technologies are fundamentally limited. They view residual stress as a purely harmful byproduct, and their goal is simply to eliminate or equalize it. Whether using thermal or mechanical energy, these methods aim to reduce overall peak stress. They fail to proactively and purposefully create a favorable stress distribution based on the performance requirements of different parts of the product.

[0006] Secondly, existing processes lack the necessary precision. For example, furnace annealing indiscriminately heats and cools the entire workpiece. This not only consumes enormous amounts of energy but can also cause undesirable metallographic changes. Vibrational aging, likewise, applies mechanical vibrations to the entire workpiece, requiring global energy input rather than local control.

[0007] Furthermore, the consistency of existing processes is difficult to guarantee. The material composition and cooling conditions of each casting batch vary slightly, leading to widely varying initial stress states. Traditional processes often rely on a fixed, empirically based set of annealing curves or vibration parameters. This open-loop, "one-size-fits-all" approach is unable to adapt to the individual differences of each workpiece. The result is inconsistent product quality, making it difficult to effectively guarantee yield rates.

[0008] Finally, these technological limitations forced product designers to adopt a conservative strategy from the outset. Unable to rely on an optimized stress field to improve component load-bearing capacity and fatigue resistance, designers were left with the most primitive methods—increasing wall thickness and reinforcing flanges—to ensure product safety. This over-design directly resulted in unnecessary weight, significant material waste, and a significant increase in manufacturing costs. Summary of the Invention

[0009] In response to the shortcomings of the existing technology, the present invention provides a method for producing large-diameter multi-channel ultrasonic water meter cases that integrates stress regulation. Due to the uncontrollable residual stress generated during the casting and machining processes, the water meter case is deformed after precision machining, which seriously affects the measurement accuracy and product yield.

[0010] To achieve the above objectives, the present invention is implemented through the following technical solutions: a method for producing a large-caliber multi-channel ultrasonic water meter case integrating stress regulation, comprising the following steps: S1: obtaining a target stress field of the water meter case workpiece; S2: obtaining the initial actual stress field of the workpiece; S3: Based on the difference between the target stress field and the actual stress field, performing closed-loop iterative local energy application on the workpiece to drive the actual stress field to approach the target stress field until the difference is less than a preset threshold; S4: After the stress field is regulated, the workpiece is precision-processed to obtain a finished watch case.

[0011] Preferably, the preset performance indicators of the water meter case are converted into mathematical constraints, and a multi-objective topology optimization algorithm is used to solve and obtain the target stress field.

[0012] Preferably, the step S2 of obtaining the initial actual stress field specifically includes: Multimodal sensing is performed on the physical workpiece to obtain its surface strain and global modal data; and the digital model is calibrated in combination with the finite element simulation results of the casting and rough machining processes to instantiate a digital twin corresponding to the physical workpiece, thereby obtaining the initial actual stress field.

[0013] Preferably, in step S3, the full-field strain distribution of the workpiece surface is acquired in real time by three-dimensional digital image correlation technology, so as to update the actual stress field in each iteration.

[0014] Preferably, the local energy application in step S3 is specifically: High-frequency acoustic energy is applied through an acoustic array composed of multiple independently drivable transducer units; and by adjusting the driving parameters of each unit, the acoustic beam is formed and focused, and the energy is accurately projected to a predetermined area of ​​the workpiece.

[0015] Preferably, the acoustic array is a conformal phased array acoustic tool head, which can adaptively fit the curved surface of the workpiece.

[0016] Preferably, step S3 includes: A stress regulation optimization problem is solved in each iteration to calculate an energy application scheme that minimizes the error between the predicted next-state stress field and the target stress field.

[0017] Preferably, the stress control optimization problem includes a dynamic system response matrix, which describes the effect of energy application on the stress field of the workpiece; In step S3, the dynamic system response matrix is ​​corrected online using a machine learning algorithm according to the deviation between the predicted result and the actual measurement result in each iteration.

[0018] Preferably, the target stress field is a spatially heterogeneous stress field, wherein: The acoustic channel area related to the propagation of ultrasonic signals is set as a zero stress area; while the pressure-bearing areas such as flanges are set as enhanced areas with preset compressive stress.

[0019] Preferably, the precision machining step S4 is performed after the internal stress field of the workpiece has been actively constructed into a stable and ideal state, so as to prevent machining deformation caused by residual stress release, thereby ensuring the final dimensional accuracy of the finished product.

[0020] The present invention provides a method for producing a large-caliber multi-channel ultrasonic water meter case with integrated stress regulation. It has the following beneficial effects: 1. This invention pre-designs the ideal target stress field for the water meter case using a performance-driven topology optimization algorithm. This approach achieves a fundamental shift from passive stress elimination to active, on-demand stress generation. Compared to existing technologies that rely on annealing or vibration aging to generally reduce or equalize residual stress, this invention overcomes the technical bottleneck of precisely generating specific, favorable stresses in different areas according to product performance requirements.

[0021] 2. This invention utilizes a closed-loop control scheme that combines a conformal phased array acoustic tool head with real-time 3D digital image feedback. Its technical benefit lies in the ability to apply high-resolution, localized energy to the workpiece, precisely driving the actual stress field toward the design target. This contrasts with existing, crude, monolithic processing methods such as heating furnaces or integral vibration tables, resolving the inherent drawbacks of these methods, which are uncontrollable and unable to achieve spatially heterogeneous stress distribution.

[0022] 3. This invention innovatively places the final precision machining step after the workpiece's internal stress field has been actively stabilized. This fundamentally eliminates workpiece deformation and dimensional springback caused by the release of residual stress induced during the cutting process. Existing techniques typically perform fine machining directly on workpieces with uncontrollable stress states, resulting in unpredictable warping of the finished product after removal from the fixture, seriously affecting the dimensional accuracy of key features such as the ultrasonic sound channel.

[0023] 4. This invention incorporates digital twinning and online machine learning technologies. The digital model is calibrated using physical measurement data, and the system response model is adaptively modified based on the actual effects of each adjustment. This gives each workpiece a unique, learnable process path. This differs from existing open-loop production models that rely on fixed process parameters, overcoming the inherent issues of poor product quality consistency and low yield rates caused by the inability to adapt to material batch differences or environmental changes.

[0024] 5. By optimizing the internal stress field through non-uniform design, this invention creates high-intensity pre-set compressive stress in critical load-bearing areas such as the flange root, while achieving a near-zero stress state in functional areas such as the sound channel. This eliminates the need to rely solely on increasing material thickness to improve product performance. Existing technologies often employ excessive and conservative material designs to ensure reliability. This invention addresses the resulting material waste, high costs, and unnecessary product bulk. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the method steps of the present invention; Figure 2 A schematic diagram of the workpiece stress field construction process of the present invention; Figure 3 Schematic diagram of the structure of the acoustic tool head of the present invention; Figure 4 It is a schematic diagram of the precision machining process of the present invention; Figure 5 It is a schematic diagram of the quality inspection process of the present invention. DETAILED DESCRIPTION

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the present specification. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0027] Please see the attached Figure 1-5 The embodiment of the present invention provides a method for producing a large-caliber multi-channel ultrasonic water meter case integrating stress regulation, comprising the following steps: S1: obtaining a target stress field of the water meter case workpiece; Specifically, in one exemplary embodiment of the present invention, the step of obtaining the target stress field focuses on reverse engineering the desired performance of the final product and converting it into a quantitative, three-dimensional stress field distribution map that can be accurately implemented during the manufacturing process. This step is completed in a digital computing environment before any machining operations are performed on the physical workpiece.

[0028] First, a high-fidelity finite element digital model of the water meter case is created. This model, based on the workpiece's 3D CAD geometry, accurately reproduces all its geometric features, including, for example, the pipe body, connecting flanges, multiple ultrasonic transducer mounting bases, and the ultrasonic signal propagation path through the pipe body.

[0029] The digital model is then imbued with detailed physical properties consistent with the actual material being used. For ductile iron, these properties include, but are not limited to, a nonlinear stress-strain constitutive relationship, temperature-dependent elastic modulus, Poisson's ratio, coefficient of thermal expansion, thermal conductivity, specific heat capacity, and fatigue S-N curve data characterizing the material's behavior under cyclic loading.

[0030] Unlike existing approaches that passively eliminate stress or rely on empirical methods, this paper adopts a performance-driven optimization design method. This method converts the key performance indicators of water meter products in actual applications into mathematical constraints that can be recognized and processed by the optimization algorithm.

[0031] For example, the performance indicators and the converted mathematical constraints may include: Dimensional stability index: To ensure the long-term accuracy of the water meter under different pipe network pressures, it is required that under the working condition of 1.5 times the nominal pressure, the longitudinal strain value of any ultrasonic sound channel must be less than a preset minimum threshold.

[0032] Fatigue life index: In order to resist the impact of cyclic loads such as water hammer effect in the pipeline network, it is required that under the action of a preset load spectrum, the cumulative fatigue damage in stress concentration areas such as the flange root must be less than the failure threshold of the material.

[0033] After establishing a digital model with precise geometry and material properties and defining performance-driven mathematical constraints, the present invention uses a multi-objective topology optimization algorithm to solve an ideal stress field that achieves optimal resource allocation while satisfying all performance constraints. The optimization problem can be formally described as: ; ; ; ; In the formula, is the stress tensor field to be solved and distributed in the workpiece volume domain, To optimize the objective function, is the volume of the workpiece, is the corresponding weight function, is the dimensional stability constraint, is the axial strain in any channel area, is the preset strain limit value, is the nominal pressure, is the fatigue life constraint condition, is the cumulative damage factor calculated based on Miner’s linear cumulative damage law, For stress levels The actual number of cycles under is the allowable number of cycles determined by the material SN curve at this stress level, is the static strength constraint, is the von Mises equivalent stress at any point, is the yield strength of the material, is the safety factor.

[0034] By solving the above optimization problem, the final output solution is the target stress field The target stress field is a three-dimensional spatially heterogeneous tensor matrix, and the stress distribution within it is actively designed to achieve specific engineering purposes.

[0035] Furthermore, the spatially heterogeneous nature of the target stress field is specifically reflected in the fact that within the acoustic channel region directly related to the ultrasonic signal propagation path, the principal stress components of the target stress field are set to values ​​close to zero. This setting minimizes the impact of stress on the speed of sound, thereby ensuring the core accuracy of water metering.

[0036] At the same time, the target stress field is set to a specific preset compressive stress value in the workpiece's main structural load-bearing areas, such as the flange connection root and the pressure-bearing pipe wall. This preset compressive stress effectively offsets the tensile stress generated by the workpiece's internal water pressure during operation, significantly improving the workpiece's fatigue resistance and structural reliability.

[0037] In summary, the present invention transforms a qualitative performance requirement into a quantitative target stress field with precise distribution in three-dimensional space and clear engineering orientation through the above-mentioned implementation methods. This target stress field serves as the only and clear target map for all subsequent physical control steps. It provides the necessary technical prerequisite for the active and precise construction of the stress field and has the objective effect of significantly improving the performance of the final product.

[0038] S2: obtaining the initial actual stress field of the workpiece; Specifically, this step aims to provide an accurate and reliable initial state benchmark for the subsequent active construction of the stress field.

[0039] This step of the invention begins with a physical workpiece that has undergone initial manufacturing. Simultaneously, a corresponding finite element digital model, incorporating simulation results from the casting and rough machining processes, has also been initially constructed. The core of this step is to calibrate this preliminary digital model using measured data from the physical world, thereby instantiating a digital twin that closely matches the physical workpiece's state.

[0040] First, multimodal sensing is performed on the physical workpiece to obtain global and local physical response data of the workpiece in a non-contact manner.

[0041] In one exemplary embodiment, multimodal sensing includes global modal analysis. Specifically, a laser Doppler vibrometer can be used to sweep the workpiece and measure its vibration response. This measurement accurately determines the workpiece's first few natural frequencies, damping ratio, and corresponding global vibration modes. These modal parameters are a comprehensive reflection of the workpiece's overall stiffness, mass distribution, and boundary constraint state, and are highly sensitive to the overall distribution of the internal stress field.

[0042] Furthermore, multimodal sensing also includes local full-field strain measurement. Exemplarily, this involves the use of three-dimensional digital image correlation technology. This process first creates a random speckle pattern on the workpiece surface to be measured. A binocular or multi-camera system then simultaneously captures digital images of the workpiece surface from different angles. By matching and calculating the displacement of the speckle pattern in the images under different conditions, a high-resolution, full-field three-dimensional displacement and strain field of the workpiece surface can be obtained.

[0043] The data obtained from physical sensing is then integrated and calibrated with the digital model. This process aims to address the inherent deviations between pure simulation models and physical reality, such as batch variations in material properties and subtle differences in actual boundary conditions.

[0044] The calibration process is constructed as an optimization problem, whose goal is to find an optimal set of model correction parameters so that the difference between the simulation output of the digital model under these parameters and the measurement results in the physical world is minimized. This optimization problem can be formally described as: ; In the formula, Represents a variable The minimization operation, is the model parameter vector to be optimized, For digital models in parameters The calculated order natural frequency, The first order natural frequency, For the The weight coefficient of the order frequency error can be set according to the sensitivity of different order frequencies. is the modal order used for calibration, Indicates the area Integrate the error on For digital models in parameters The surface strain field calculated under is the surface strain field actually measured by 3D-DIC technology. represents the square difference between the strain calculated by FEM and the strain measured by DIC, is the measured surface area.

[0045] By solving the above formula using efficient optimization algorithms such as conjugate gradient method or sequential quadratic programming, a set of optimal model correction parameters can be obtained. .

[0046] The optimal parameters of this group After updating to the original finite element digital model, the model evolves from a general predictive model to a high-fidelity digital twin that corresponds one-to-one to the current physical workpiece.

[0047] Finally, the complete three-dimensional stress field distribution inside the instantiated digital twin is extracted. This stress field is the initial actual stress field defined in this invention. . Since the stress field is a product that integrates dual information of simulation prediction and physical measurement, it can more accurately and comprehensively reflect the actual stress state of the physical workpiece before entering the active control link than a single simulation or measurement method. In summary, the present invention, through the above-mentioned implementation method, systematically combines multimodal physical sensing technology and digital simulation model correction technology, and can obtain a high-precision initial actual stress field that is synchronized with the state of the physical workpiece. This step provides a reliable initial condition for the subsequent closed-loop iterative stress control, and is a necessary prerequisite for ensuring the accuracy and effectiveness of the entire production method.

[0048] S3: Based on the difference between the target stress field and the actual stress field, performing closed-loop iterative local energy application on the workpiece to drive the actual stress field to approach the target stress field until the difference is less than a preset threshold; Specifically, within a closed-loop iterative control framework, this step drives the workpiece's actual stress field toward the pre-designed target stress field by precisely applying local energy. This step begins with the initial actual stress field obtained in step S2 and ends with the target stress field defined in step S1.

[0049] First, in order to implement this closed-loop iterative control, it is necessary to deploy a physical system including an energy application unit and a state perception unit.

[0050] In one exemplary embodiment, the energy application unit is specifically an acoustic actuator system. This system includes a conformal phased array acoustic tool head comprising a flexible substrate on which are integrated an array of multiple independently drivable piezoelectric transducer units. The properties of the flexible substrate enable it to adaptively conform to the complex curved surface of the workpiece, ensuring good acoustic coupling.

[0051] Furthermore, the state sensing unit is specifically a real-time strain measurement system. For example, a three-dimensional digital image correlation system is employed. This system operates continuously throughout the entire control process, capable of acquiring the full-field strain distribution of the workpiece surface in real time with high temporal and spatial resolution, providing timely state feedback for closed-loop control.

[0052] After system deployment, the method enters a closed-loop iterative control cycle consisting of a series of consecutive "decision-execution-perception-evaluation" sub-steps until the difference between the actual stress field of the workpiece and the target stress field meets the convergence condition.

[0053] In the At the beginning of the iteration cycle, the control system first executes the decision-making sub-step. The core of this step is to solve a stress control optimization problem, whose goal is to calculate the energy application scheme that can most efficiently push the actual stress field to the target stress field under the current state. This optimization problem can be formally described as: ; In the formula, is the acoustic intervention parameter vector to be solved. This vector contains the driving parameters of each transducer unit in the acoustic array in this iteration, such as the amplitude, frequency, and phase of the driving signal.

[0054] For the At the beginning of the iteration, the current actual stress tensor field obtained by the real-time strain measurement system is is the final target stress tensor field determined in the previous step, is a diagonal spatial weight matrix, is a dynamic system response matrix, is the small action time step of an acoustic intervention, is the Hadamard product (element-wise multiplication), is the Frobenius norm, which is used to quantify the overall gap between the predicted next-state stress field and the target stress field.

[0055] A key technical feature is that the dynamic system response matrix It is not static, but has the ability to learn and adapt online. After each iteration of energy application is completed, the system will compare Using the deviation between the predicted stress field changes and the stress field changes actually measured by the perception system, a machine learning model can correct the The correction process can be expressed as follows: ; In the formula, is a machine learning algorithm model, It is the new stress field actually measured by the sensing system after energy is applied. is the stress field predicted after energy is applied based on the expression in the brackets of the above formula.

[0056] This adaptive correction mechanism enables the present invention to autonomously compensate for the impact of uncertain factors such as slight differences in material properties and changes in ambient temperature, thereby significantly improving the robustness and accuracy of control.

[0057] In the decision sub-step, the optimal intervention parameter vector is obtained by solving the above formula After that, the system enters the execution substep. The control system converts this parameter vector into a physical drive signal and applies it to each transducer element of the conformal phased array acoustic tool head. By precisely controlling the phase of the drive signal to each element, the acoustic array can achieve acoustic beam shaping and focusing, precisely projecting high-frequency acoustic energy in a controlled manner to a predetermined area on the workpiece surface, subsurface, or interior, thereby modifying local stress.

[0058] The 3D digital image correlation technology system immediately performs a new full-field strain measurement to obtain the new actual stress field after energy application. , and feeds the data back to the control system as the initial state for the next iteration.

[0059] Finally, the system performs the evaluation sub-step. The new actual stress field is calculated. With the target stress field If the difference is less than a preset convergence threshold , then the entire closed-loop iteration process ends. If the convergence condition is not met, the iteration index After adding one, the system returns to the decision-making substep and begins a new round of control loop. Through the above-mentioned embodiments, the present invention can perform surgical-like precise energy application on the workpiece in a closed-loop, iterative, and adaptive manner, thereby actively and deterministically reconstructing the internal stress field of the workpiece from any initial state to a pre-designed ideal target state.

[0060] S4: Precision machining the workpiece after stress field control is completed to obtain a finished watch case; Specifically, this step is performed on a workpiece whose internal stress field has been actively structured into a stable and ideal state, with the aim of giving the workpiece final, high-precision geometric dimensions to obtain the finished watch case.

[0061] This step is followed by the completion of step S3. At this point, the actual stress field inside the workpiece has been accurately driven to the preset target stress field under closed-loop control. Highly consistent state. In this state, the internal stress distribution of the workpiece is engineered, stable, and well adapted to subsequent processing.

[0062] First, the workpiece, after stress field manipulation, is removed from the specialized flexible tooling used for stress manipulation and transferred to precision machining equipment. For example, this precision machining equipment can be a five-axis CNC machining center with high-precision positioning and repeatability. The workpiece is re-clamped and positioned on this equipment using non-critical features or specialized fixtures. Because the workpiece is already in a stress-stable state, the rigid clamping force applied here will not cause subsequent unintended deformation.

[0063] The workpiece is then subjected to final machining operations on this precision machining equipment according to a pre-set CNC program. These operations are designed to remove the machining allowances (e.g., 1mm) reserved in the previous process and to produce the precise geometric features with the tight tolerances required by the final design drawings.

[0064] In an exemplary embodiment, the precision machining operations include, but are not limited to: The inner walls of the multiple ultrasonic signal propagation sound channels of the water meter case are finally precisely bored or reamed to ensure that their final diameter, roundness, cylindricity and inner wall surface roughness meet the design requirements.

[0065] The flange sealing surfaces and sealing ring grooves at both ends of the case are precisely turned or milled to ensure their flatness, parallelism and perpendicularity to the axis of the tube body.

[0066] The end faces and positioning holes of the transducer mounting base are precisely milled and bored to ensure high consistency in the mounting positions and angles of all transducers.

[0067] Complete the drilling and tapping operations of all remaining connecting holes and functional holes.

[0068] A key technical feature of the present invention lies in the timing of precision machining, which involves performing high-material-removal finishing operations after the workpiece's internal stresses have been actively stabilized. This timing fundamentally addresses the problem of machining deformation caused by residual stress release, a common problem in traditional processes.

[0069] Specifically, in traditional processes, finishing cuts themselves can become a trigger for releasing unbalanced residual stresses introduced by processes like casting or heat treatment, causing dimensional springback or warping in the workpiece after it is released from the fixture. However, in the present invention, because the stress field has already been reshaped to an engineered, stable equilibrium state in the previous steps, material removal during finishing does not disrupt this pre-set equilibrium, allowing the workpiece to maintain its macroscopic geometry both before and after machining and after release from the fixture.

[0070] The dimensional accuracy and shape stability that can be achieved in this step can be objectively described and verified using the following formula: ; In the formula, After the processing is completed in this step, the actual value of any key geometric dimension is measured by a measuring device such as a three-coordinate measuring machine. is the theoretical value of the geometric dimension specified in the design drawing, It is the design tolerance zone of the geometric dimension.

[0071] After all precision machining operations are completed, the workpiece becomes a finished watch case that meets the requirements of its final use.

[0072] Furthermore, to verify the overall effectiveness of the present invention and establish a quality profile for each product, the finished watch case can undergo a final quality inspection. This inspection includes full-scale inspection of all key geometric dimensions and form and position tolerances using a coordinate measuring machine, generating a complete geometric dimension inspection report to verify compliance with the above formula.

[0073] At the same time, the residual stress of key areas of the finished product (such as the inner wall of the sound channel and the root of the flange) can be measured by random inspection using an X-ray diffraction stress analyzer. The purpose of this measurement is to verify that the precision machining process itself does not introduce new and harmful surface residual stresses, and that the workpiece as a whole still maintains the target stress field. The corresponding stress state.

[0074] Finally, the geometric dimension inspection report and stress state verification report generated in this step are associated and archived with all the data recorded for the unique serial number workpiece in previous steps S1, S2, and S3 (including the target stress field definition, digital twin calibration data, and stress control iteration process data) to form a complete digital birth certificate.

[0075] In summary, the present invention effectively solves the problem of processing deformation caused by residual stress release in traditional manufacturing through a specific process sequence of precision processing after active construction of the stress field, thereby reliably obtaining a finished watch case with high dimensional accuracy and high shape stability, and providing complete traceable data for the entire life cycle of the product.

[0076] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for producing a large-caliber multi-channel ultrasonic water meter case integrating stress regulation, characterized in that: The following steps are involved: S1: obtaining a target stress field of the water meter case workpiece; S2: obtaining the initial actual stress field of the workpiece; S3: Based on the difference between the target stress field and the actual stress field, performing closed-loop iterative local energy application on the workpiece to drive the actual stress field to approach the target stress field until the difference is less than a preset threshold; S4: After the stress field is regulated, the workpiece is precision-processed to obtain a finished watch case.

2. The method for producing a large-caliber multi-channel ultrasonic water meter case with integrated stress regulation according to claim 1 is characterized in that: The preset performance indicators of the water meter case are converted into mathematical constraints, and a multi-objective topology optimization algorithm is used to solve and obtain the target stress field.

3. The method for producing a large-caliber multi-channel ultrasonic water meter case with integrated stress regulation according to claim 1 is characterized in that: The step S2 of obtaining the initial actual stress field specifically includes: Multimodal sensing is performed on the physical workpiece to obtain its surface strain and global modal data; and the digital model is calibrated in combination with the finite element simulation results of the casting and rough machining processes to instantiate a digital twin corresponding to the physical workpiece, thereby obtaining the initial actual stress field.

4. The method for producing a large-caliber multi-channel ultrasonic water meter case with integrated stress regulation according to claim 1 is characterized in that: In step S3, the full-field strain distribution of the workpiece surface is acquired in real time by using a three-dimensional digital image correlation technique, so as to update the actual stress field in each iteration.

5. The method for producing a large-caliber multi-channel ultrasonic water meter case with integrated stress regulation according to claim 1 is characterized in that: The local energy application in step S3 is specifically as follows: High-frequency acoustic energy is applied through an acoustic array composed of multiple independently drivable transducer units; and by adjusting the driving parameters of each unit, the acoustic beam is formed and focused, and the energy is accurately projected to a predetermined area of ​​the workpiece.

6. The method for producing a large-caliber multi-channel ultrasonic water meter case with integrated stress regulation according to claim 5 is characterized in that: The acoustic array is a conformal phased array acoustic tool head that can adaptively fit the curved surface of the workpiece.

7. The method for producing a large-caliber multi-channel ultrasonic water meter case with integrated stress regulation according to claim 1 is characterized in that: The step S3 comprises: A stress regulation optimization problem is solved in each iteration to calculate an energy application scheme that minimizes the error between the predicted next-state stress field and the target stress field.

8. The method for producing a large-caliber multi-channel ultrasonic water meter case with integrated stress regulation according to claim 7, characterized in that: The stress control optimization problem includes a dynamic system response matrix, which describes the effect of energy application on the stress field of the workpiece; In step S3, the dynamic system response matrix is ​​corrected online using a machine learning algorithm according to the deviation between the predicted result and the actual measurement result in each iteration.

9. The method for producing a large-caliber multi-channel ultrasonic water meter case with integrated stress regulation according to claim 2, characterized in that: The target stress field is a spatially heterogeneous stress field, wherein: The acoustic channel area related to the propagation of ultrasonic signals is set as a zero stress area; while the pressure-bearing areas such as flanges are set as enhanced areas with preset compressive stress.

10. The method for producing a large-caliber multi-channel ultrasonic water meter case with integrated stress regulation according to claim 1, characterized in that: The step S4 of performing precision machining is performed after the internal stress field of the workpiece has been actively constructed into a stable and ideal state, so as to prevent machining deformation caused by residual stress release, thereby ensuring the final dimensional accuracy of the finished product.

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