Valve casting gradient cooling control method and system

Abstract

The embodiment of the application provides a valve casting gradient cooling control method and system, relates to the technical field of valve casting gradient cooling, and comprises the following steps: obtaining first temperature information and second temperature information, wherein the first temperature information represents temperature information of a thick wall area of the casting, and the second temperature information represents temperature information of a thin wall area of the casting; obtaining an actual temperature difference value according to the first temperature information and the second temperature information; generating a control adjustment amount according to the actual temperature difference value and a preset target temperature difference value; and adjusting the cooling intensity of the thick wall area according to the control adjustment amount, the actual temperature difference value and the preset target temperature difference value. The embodiment of the application can improve the quality and reliability of the casting.

Description

Technical Field

[0001] This application relates to the field of gradient cooling technology for valve castings, and in particular to a gradient cooling control method and system for valve castings. Background Technology

[0002] In existing technologies, for castings with complex structures and large differences in wall thickness, such as valve castings, the heat dissipation rate varies significantly between different regions during the cooling process. Thin-walled areas cool quickly, while thick-walled areas cool slowly, resulting in different microstructures and hardnesses in different regions. This leads to significant residual stress at the interface where wall thickness changes drastically. This residual stress may cause cracks during subsequent processing, affecting product yield. While simple overall slow cooling can reduce microstructure differences, it may cause the material to remain in a specific temperature range for too long, inducing the precipitation of harmful phases and impairing material properties. Attempts to locally accelerate cooling thick-walled areas are difficult to control precisely in terms of cooling intensity and timing, easily leading to thermal fatigue cracks on the casting surface or insufficient cooling, failing to effectively eliminate internal stress. Especially for areas with complex geometries (such as sharp internal angles), their cooling behavior is affected by multiple factors, and simple local cooling schemes cannot accurately manage the temperature drop rate in these areas. Furthermore, in mass production, the local environmental heat dissipation conditions of the castings vary, and a preset fixed control strategy cannot adapt to these individual differences, resulting in poor product quality consistency. Summary of the Invention

[0003] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a gradient cooling control method and system for valve castings, aiming to improve the quality and reliability of the castings.

[0004] In a first aspect, embodiments of this application provide a gradient cooling control method for valve castings, applied to castings, including:

[0005] Acquire first temperature information and second temperature information, wherein the first temperature information represents the temperature information of the thick-walled region of the casting, and the second temperature information represents the temperature information of the thin-walled region of the casting.

[0006] Based on the first temperature information and the second temperature information, the actual temperature difference value is obtained;

[0007] Based on the actual temperature difference and the preset target temperature difference, a control adjustment amount is generated;

[0008] The cooling intensity of the thick-walled region is adjusted according to the control adjustment amount, the actual temperature difference value, and the preset target temperature difference value.

[0009] According to some embodiments of this application, obtaining the actual temperature difference value based on the first temperature information and the second temperature information includes:

[0010] Based on the second temperature information and the preset reference temperature correspondence, the first predicted temperature information is determined, wherein the preset reference temperature correspondence characterizes the temperature relationship between the thick-walled region and the thin-walled region of the casting under natural cooling conditions;

[0011] Based on the first predicted temperature information and the first temperature information, the measurement deviation value is obtained;

[0012] The first temperature information is corrected based on the measurement deviation value to obtain the corrected first temperature information;

[0013] Based on the corrected first temperature information and the second temperature information, the actual temperature difference value is obtained.

[0014] According to some embodiments of this application, the preset target temperature difference value is obtained through the following steps:

[0015] Obtain a reference temperature difference relationship, wherein the reference temperature difference relationship characterizes the relationship of the thermophysical properties of the reference material batch;

[0016] During the preset cooling phase, a first series of temperature information for the thick-walled region and a second series of temperature information for the thin-walled region of the casting are acquired.

[0017] Based on the first series of temperature information and the second series of temperature information, the actual cooling characteristic parameters are determined.

[0018] The reference temperature difference relationship is adjusted based on the actual cooling characteristic parameters to generate the adjusted temperature difference relationship;

[0019] The preset target temperature difference value is determined based on the preset cooling stage and the adjusted temperature difference relationship.

[0020] According to some embodiments of this application, determining the actual cooling characteristic parameters based on the first series of temperature information and the second series of temperature information includes:

[0021] Based on the second series of temperature information, environmental heat dissipation parameters are obtained, wherein the environmental heat dissipation parameters are parameters that characterize the local environmental heat dissipation conditions of the casting.

[0022] Based on the first series of temperature information and the second series of temperature information, intermediate characteristic parameters are obtained;

[0023] The actual cooling characteristic parameters are determined based on the environmental heat dissipation parameters and the intermediate characteristic parameters.

[0024] According to some embodiments of this application, adjusting the reference temperature difference relationship based on the actual cooling characteristic parameters to generate an adjusted temperature difference relationship includes:

[0025] Obtain process constraints, wherein the process constraints characterize the conditions of multiple process target boundaries during the cooling process of the casting;

[0026] The reference temperature difference relationship is adjusted based on the actual cooling characteristic parameters and the process constraints to generate the adjusted temperature difference relationship.

[0027] According to some embodiments of this application, the process constraints are obtained through the following steps:

[0028] Obtain the partition information of multiple functional partitions of the casting;

[0029] Based on the partition information, the partition process constraints corresponding to each functional partition are obtained;

[0030] The process constraints are generated by combining the process constraints corresponding to each functional partition.

[0031] According to some embodiments of this application, obtaining the partitioning process constraints corresponding to each functional partition based on the partitioning information includes:

[0032] Obtain the initial partitioning process constraints for each of the functional partitions and the adjacent functional partition pairs among the multiple functional partitions;

[0033] In the event of a conflict between the initial partitioning process constraints corresponding to the adjacent functional partition pairs, a transition region at the boundary of the adjacent functional partition pairs is determined.

[0034] Based on the initial partitioning process constraints, the transition process constraints for the transition region are generated.

[0035] Based on the transition process constraints and the transition region, the partition process constraints corresponding to each functional partition are obtained.

[0036] According to some embodiments of this application, the partitioned process constraints include at least one cooling rate constraint and at least one temperature difference constraint.

[0037] According to some embodiments of this application, determining the actual cooling characteristic parameters based on the first series of temperature information and the second series of temperature information includes:

[0038] Calculate the series of actual temperature differences between the first series of temperature information and the second series of temperature information;

[0039] Based on the series of actual temperature difference values, determine the decay characteristic parameters of the series of actual temperature difference values ​​over time;

[0040] The actual cooling characteristic parameters are obtained based on the attenuation characteristic parameters.

[0041] Secondly, embodiments of this application provide a gradient cooling control system for valve castings, comprising:

[0042] The acquisition module is used to acquire first temperature information and second temperature information, wherein the first temperature information represents the temperature information of the thick-walled region of the casting, and the second temperature information represents the temperature information of the thin-walled region of the casting.

[0043] The calculation module is used to calculate the actual temperature difference value based on the first temperature information and the second temperature information.

[0044] The generation module is used to generate a control adjustment amount based on the actual temperature difference value and the preset target temperature difference value;

[0045] The adjustment module adjusts the cooling intensity of the thick-walled region according to the control adjustment amount, the actual temperature difference value, and the preset target temperature difference value.

[0046] According to the technical solution of the embodiments of this application, at least the following beneficial effects are achieved: The embodiments of the present invention first obtain first temperature information and second temperature information, wherein the first temperature information represents the temperature information of the thick-walled region of the casting, and the second temperature information represents the temperature information of the thin-walled region of the casting; based on the first temperature information and the second temperature information, an actual temperature difference value is obtained; based on the actual temperature difference value and a preset target temperature difference value, a control adjustment amount is generated; and based on the control adjustment amount, the actual temperature difference value, and the preset target temperature difference value, the cooling intensity of the thick-walled region is adjusted. The embodiments of this application can improve the quality and reliability of castings.

[0047] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0048] The accompanying drawings are used to provide a further understanding of the technical solutions of this application and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of this application and do not constitute a limitation on the technical solutions of this application.

[0049] Figure 1 A schematic flowchart of a gradient cooling control method for valve castings provided in one embodiment of this application;

[0050] Figure 2This is a schematic diagram of the process for obtaining the actual temperature difference value according to one embodiment of this application;

[0051] Figure 3 This is a schematic diagram of a process for obtaining a preset target temperature difference value according to an embodiment of this application;

[0052] Figure 4 This is a schematic diagram of a process for obtaining actual cooling characteristic parameters according to one embodiment of this application;

[0053] Figure 5 This is a schematic diagram of the process for generating the adjusted temperature difference relationship according to one embodiment of this application;

[0054] Figure 6 A schematic flowchart illustrating the process of obtaining process constraints according to one embodiment of this application;

[0055] Figure 7 This is a flowchart illustrating the process constraints for obtaining the partitioning process conditions corresponding to each functional partition, provided as an embodiment of this application.

[0056] Figure 8 This is a schematic diagram illustrating the process of obtaining actual cooling characteristic parameters according to one embodiment of this application;

[0057] Figure 9 This is a schematic diagram of a gradient cooling control system for valve castings provided in one embodiment of this application. Detailed Implementation

[0058] To make the objectives, technical methods, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0059] It should be noted that the meaning of "multiple" (or "more than") in the description of the embodiments of this application refers to two or more, and "greater than," "less than," "exceeding," etc. are understood to exclude the number itself, while "above," "below," "within," etc. are understood to include the number itself. If "first," "second," etc. are used in the description, they are only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated or the order of the technical features indicated.

[0060] In this application embodiment, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent the existence of A alone, the simultaneous existence of A and B, or the existence of B alone. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of singular or plural items. For example, at least one of a, b, and c can represent: the existence of a alone, the existence of b alone, the existence of c alone, the simultaneous existence of a and b, the simultaneous existence of a and c, the simultaneous existence of b and c, or the simultaneous existence of a, b, and c, where a, b, and c can be single or multiple.

[0061] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0062] Based on the above, this application proposes a gradient cooling control method and system for valve castings, aiming to improve the quality and reliability of the castings.

[0063] The gradient cooling control method for valve castings provided in this application can be applied to a terminal, a server, or software running on either a terminal or a server. In some embodiments, the terminal can be a smartphone, tablet, laptop, desktop computer, etc.; the server can be configured as an independent physical server, a server cluster or distributed system composed of multiple physical servers, or a cloud server providing basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, content delivery networks (CDN), and big data and artificial intelligence platforms; the software can be an application that implements the gradient cooling control method for valve castings, but is not limited to the above forms.

[0064] This application can be applied to numerous general-purpose or special-purpose computer system environments or configurations. Examples include: personal computers, server computers, handheld or portable devices, tablet devices, multiprocessor systems, microprocessor-based systems, set-top boxes, programmable consumer electronics devices, network PCs, minicomputers, mainframe computers, and distributed computing environments including any of the above systems or devices. This application can be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform specific tasks or implement specific abstract data types. This application can also be practiced in distributed computing environments where tasks are performed by remote processing devices connected via communication networks. In distributed computing environments, program modules can reside in local and remote computer storage media, including storage devices. It should be noted that in various specific embodiments of this invention, when processing is required based on data related to the characteristics of an object (e.g., user attributes or sets of attribute information), permission or consent from the corresponding object is obtained first, and the collection, use, and processing of this data comply with relevant laws and standards. Furthermore, when the embodiments of the present invention need to obtain the attribute information of an object, they will obtain the separate permission or separate consent of the corresponding object through pop-up windows or redirection to a confirmation page. After obtaining the separate permission or separate consent of the corresponding object, they will then obtain the relevant data of the object necessary for the embodiments of the present invention to operate normally.

[0065] See Figure 1 , Figure 1 This is a flowchart illustrating a gradient cooling control method for valve castings according to an embodiment of this application. The gradient cooling control method for valve castings provided in this embodiment includes, but is not limited to, steps S110 to S140, which are described below.

[0066] Step S110: Obtain first temperature information and second temperature information, wherein the first temperature information represents the temperature information of the thick-walled region of the casting, and the second temperature information represents the temperature information of the thin-walled region of the casting.

[0067] Step S120: Obtain the actual temperature difference value based on the first temperature information and the second temperature information;

[0068] Step S130: Generate a control adjustment amount based on the actual temperature difference value and the preset target temperature difference value;

[0069] Step S140: Adjust the cooling intensity of the thick-walled region according to the control adjustment amount, the actual temperature difference value, and the preset target temperature difference value.

[0070] It should be noted that the first temperature information represents the temperature of the thick-walled region of the casting, and can be implemented using contact or non-contact temperature sensors, such as thermocouples or infrared thermometers; the second temperature information represents the temperature of the thin-walled region of the casting, and can also be implemented using contact or non-contact temperature sensors, such as thermocouples or infrared thermometers; the actual temperature difference is the temperature difference calculated based on the first and second temperature information; the preset target temperature difference refers to the desired temperature difference between the thick and thin-walled regions during the casting cooling process, which can be preset based on process requirements or simulation results, providing a reference benchmark for cooling control; the control adjustment quantity is a control signal generated based on the deviation between the actual temperature difference and the preset target temperature difference, and can be generated using proportional, integral, or derivative control algorithms; adjusting the cooling intensity of the thick-walled region refers to changing the strength of the cooling effect applied to the thick-walled region of the casting, which can be achieved by changing the flow rate, temperature, spray area, or duration of the cooling medium, mainly to affect the temperature difference between the thick and thin walls by changing the heat dissipation rate of the thick-walled region.

[0071] In one embodiment, when the actual temperature difference is greater than the target temperature difference, it may be necessary to increase the cooling intensity of the thick-walled region to reduce the temperature difference; conversely, when the actual temperature difference is less than the target temperature difference, it may be necessary to reduce the cooling intensity of the thick-walled region. The entire process forms a feedback loop, where the system continuously monitors the temperature difference and dynamically adjusts the cooling intensity, ensuring that the actual temperature difference value continuously approaches or remains near the preset target temperature difference value. This achieves precise management of the cooling rate in both thick and thin-walled regions of the casting, avoiding stress concentration and cracking caused by uneven cooling. This dynamic adjustment mechanism can adapt to changes in heat dissipation of the casting under different cooling environments, ensuring the stability and consistency of the cooling process.

[0072] It is worth noting that the first and second temperature information can be obtained in real time by thermocouples arranged on the surfaces of the thick-walled and thin-walled regions of the casting or by a non-contact infrared thermometer. The actual temperature difference can be calculated in a control unit, and the preset target temperature difference can be stored in the memory of the control unit. The preset target temperature difference can be determined in the casting process design stage according to the material properties and structural characteristics. The control adjustment can be calculated and generated by the PID controller running in the control unit based on the deviation between the actual temperature difference and the preset target temperature difference. The cooling intensity of the thick-walled region can be adjusted by controlling the valve opening of the cooling device (e.g., spray head) connected to the thick-walled region or the power of the cooling medium pump, thereby changing the flow rate or spray rate of the cooling medium.

[0073] See Figure 2 , Figure 2This is a schematic diagram of the process for obtaining the actual temperature difference value according to an embodiment of this application; regarding the above step S120, which obtains the actual temperature difference value based on the first temperature information and the second temperature information, it includes, but is not limited to, steps S210 to S240, and each step will be described in turn below.

[0074] Step S210: Determine the first predicted temperature information based on the second temperature information and the preset reference temperature correspondence, wherein the preset reference temperature correspondence characterizes the temperature relationship between the thick-walled region and the thin-walled region of the casting under natural cooling conditions.

[0075] Step S220: Obtain the measurement deviation value based on the first predicted temperature information and the first temperature information;

[0076] Step S230: Correct the first temperature information based on the measurement deviation value to obtain the corrected first temperature information;

[0077] Step S240: Based on the corrected first and second temperature information, obtain the actual temperature difference value.

[0078] It should be noted that the preset reference temperature correspondence represents a preset relationship between the temperatures of the thick-walled and thin-walled regions of the casting under natural cooling conditions. This relationship can be implemented using a lookup table, mathematical functions, or a model based on historical data / simulation results. The first predicted temperature information is a predicted temperature value representing the thick-walled region under natural cooling conditions, obtained based on the second temperature information and the preset reference temperature correspondence. The measurement deviation value is the difference between the first predicted temperature information and the first temperature information, which can be obtained by calculating the difference between the two. The corrected first temperature information refers to the temperature information after adjusting the first temperature information based on the measurement deviation value. This can reduce the impact of measurement errors on the temperature value of the thick-walled region and improve the accuracy of the temperature information.

[0079] It is worth noting that the method in this application avoids directly using potentially biased original measurements to calculate the temperature difference, resulting in a more accurate actual temperature difference value. Using this more accurate actual temperature difference value for subsequent control adjustment and cooling intensity regulation allows the control system to respond more precisely to temperature differences in different areas of the casting, thereby more effectively managing the temperature gradient, reducing residual stress, lowering the risk of cracking, and improving product quality consistency. This correction mechanism, combined with the basic temperature difference control method, forms a more robust and precise gradient cooling control strategy.

[0080] See Figure 3 , Figure 3This is a schematic diagram of a process for obtaining a preset target temperature difference value according to an embodiment of this application. The preset target temperature difference value in step S130 includes, but is not limited to, steps S310 to S350, which will be described in detail below.

[0081] Step S310: Obtain the reference temperature difference relationship, wherein the reference temperature difference relationship characterizes the relationship of the thermophysical properties of the reference material batch;

[0082] Step S320: During the preset cooling stage, acquire the first series of temperature information of the thick-walled region and the second series of temperature information of the thin-walled region of the casting.

[0083] Step S330: Based on the first series of temperature information and the second series of temperature information, determine the actual cooling characteristic parameters;

[0084] Step S340: Adjust the reference temperature difference relationship according to the actual cooling characteristic parameters to generate the adjusted temperature difference relationship;

[0085] Step S350: Determine the preset target temperature difference value based on the preset cooling stage and the adjusted temperature difference relationship.

[0086] In one embodiment, the reference temperature difference relationship reflects the thermophysical properties of a reference material batch. Since different batches of material may have slight differences in composition or microstructure, their thermophysical properties differ, thus affecting the temperature difference distribution during cooling. By monitoring the temperature changes in thick-walled and thin-walled regions during actual cooling, the actual cooling situation of the casting can be understood. The actual cooling characteristic parameters reflect the heat dissipation capacity and temperature distribution characteristics of the casting under specific cooling conditions. By analyzing the actual temperature data, parameters closely related to the cooling process can be extracted, such as the heat dissipation coefficient and temperature gradient. By combining the actual cooling characteristic parameters with the reference temperature difference relationship, the reference temperature difference relationship can be corrected to better reflect the actual situation of the current casting. This adjustment considers various factors in the actual cooling process, including ambient temperature and cooling medium, thereby improving the accuracy of the preset target temperature difference value. By applying the adjusted temperature difference relationship to a preset cooling stage, the preset target temperature difference value to be set in that stage can be obtained. Therefore, the preset target temperature difference value can be dynamically adjusted according to different cooling stages, thereby achieving more precise cooling control.

[0087] In one embodiment, a standard cooling experiment is conducted using a reference material casting. The temperatures of thick-walled and thin-walled regions are measured simultaneously, and their changes over time or temperature are recorded. These curves or their mathematical models are used as a reference temperature difference relationship. During a preset cooling phase, the first and second series of temperature information are acquired. This can begin when the casting temperature drops to 800°C and ends at 400°C. Using an infrared thermometer or thermocouple, surface temperature data for thick-walled regions (e.g., the outer wall of the main cavity) and thin-walled regions (e.g., the outer wall of the guide sleeve) are continuously collected at a frequency of once per second, forming two temperature sequences. Based on the first and second series of temperature information, the actual cooling characteristic parameters are determined. Alternatively, based on the collected first and second series of temperature information, the actual temperature difference sequence between the two regions is calculated. The rate of change or decay trend of this temperature difference sequence over time is analyzed, and the exponential decay constant of the temperature difference over time is calculated. This constant is used as the actual cooling characteristic parameter. Alternatively, the equivalent heat dissipation coefficient of the current environment can be estimated based on the temperature change rate of the thin-walled region, combined with a heat transfer model, and used as the actual cooling characteristic parameter. Adjusting the baseline temperature difference relationship based on actual cooling characteristic parameters to generate the adjusted temperature difference relationship can be achieved by establishing a mathematical model. This model is based on the baseline temperature difference relationship and incorporates actual cooling characteristic parameters as correction factors. For example, if the actual cooling characteristic parameters indicate that the current heat dissipation conditions are worse than the baseline conditions, the model will predict that the thick-wall temperature will be relatively higher at the same thin-wall temperature, thereby adjusting the baseline temperature difference relationship and generating an adjusted temperature difference relationship curve that reflects the current actual situation. Alternatively, a lookup table can be established in advance, and the corresponding adjustment coefficient can be found in the table based on the actual cooling characteristic parameters. Then, the baseline temperature difference relationship can be multiplied by the adjustment coefficient to obtain the adjusted temperature difference relationship. Based on the preset cooling stage and the adjusted temperature difference relationship, the preset target temperature difference value can be determined within the preset cooling stage. According to the current thin-walled area temperature or time, the preset target temperature difference value between the thick-walled area and the thin-walled area can be found in the adjusted temperature difference relationship curve or lookup table. For example, if the thin-walled area temperature is 600℃ at a certain moment in the preset cooling stage, the preset target temperature difference value corresponding to the thin-walled area temperature of 600℃ can be found in the adjusted temperature difference relationship. For example, if it is 50℃, then the preset target temperature difference value at this time is 50℃.

[0088] See Figure 4 , Figure 4 This is a schematic flowchart illustrating the process of obtaining actual cooling characteristic parameters according to an embodiment of this application. Regarding step S310, which determines the actual cooling characteristic parameters based on the first series of temperature information and the second series of temperature information, this includes, but is not limited to, steps S410 to S430, which will be described in detail below.

[0089] Step S410: Based on the second series of temperature information, obtain the environmental heat dissipation parameters, wherein the environmental heat dissipation parameters characterize the parameters of the local environmental heat dissipation conditions of the casting.

[0090] Step S420: Based on the first series of temperature information and the second series of temperature information, obtain intermediate characteristic parameters;

[0091] Step S430: Determine the actual cooling characteristic parameters based on the environmental heat dissipation parameters and intermediate characteristic parameters.

[0092] It should be noted that temperature changes in thin-walled regions are more susceptible to environmental heat dissipation conditions. By monitoring temperature changes in these regions, the local environmental heat dissipation conditions of the casting can be deduced. Incorporating environmental heat dissipation parameters allows for a more comprehensive assessment of the overall cooling state of the casting, overcoming the shortcomings of traditional methods that neglect environmental factors and making subsequent cooling control strategies more targeted. Since temperature information from both thick-walled and thin-walled regions contains information about the casting's cooling characteristics, comprehensively considering the temperature information from both regions provides a more complete reflection of the casting's overall cooling state. Combining these two factors allows for a more accurate assessment of the casting's actual cooling characteristics. By integrating environmental heat dissipation parameters with intermediate characteristic parameters, the actual cooling characteristics of the casting can be more accurately assessed, providing a more reliable basis for subsequent adjustments to temperature difference relationships.

[0093] See Figure 5 , Figure 5 This is a schematic flowchart illustrating the process of generating an adjusted temperature difference relationship according to an embodiment of this application. The above step S340, which adjusts the baseline temperature difference relationship based on actual cooling characteristic parameters to generate the adjusted temperature difference relationship, includes, but is not limited to, steps S510 to S520. Each step will be described in turn below.

[0094] Step S510: Obtain process constraints, wherein the process constraints characterize the conditions of multiple process target boundaries during the casting cooling process;

[0095] Step S520: Adjust the baseline temperature difference relationship according to the actual cooling characteristic parameters and process constraints to generate the adjusted temperature difference relationship.

[0096] It should be noted that process constraints characterize the boundary conditions of multiple process objectives during the casting cooling process. These conditions may include cooling rate requirements for different functional zones, temperature gradient limitations, etc. Obtaining these process constraints provides important reference for subsequent temperature difference relationship adjustments. After initially adjusting the baseline temperature difference relationship using actual cooling characteristic parameters, the influence of process constraints needs to be further considered to correct the adjustment results. If a certain functional zone has a high cooling rate requirement, the cooling intensity of that area needs to be appropriately increased to meet the process requirements. By comprehensively considering actual cooling characteristic parameters and process constraints, an adjusted temperature difference relationship that better meets actual needs can be generated, thereby better controlling the casting cooling process.

[0097] In one embodiment, when actual cooling characteristic parameters indicate that the casting cools relatively quickly, but process constraints require that the cooling rate in certain areas cannot be too fast, the cooling intensity in these areas needs to be appropriately reduced to meet the process requirements. Conversely, when actual cooling characteristic parameters indicate that the casting cools relatively slowly, but process constraints require that the cooling rate in certain areas must reach a certain level, the cooling intensity in these areas needs to be appropriately increased to ensure that the process requirements are met.

[0098] See Figure 6 , Figure 6 This is a schematic flowchart illustrating the process of obtaining process constraints according to an embodiment of this application. The process constraint acquisition step S510 described above includes, but is not limited to, steps S610 to S630, which will be described in detail below.

[0099] Step S610: Obtain the partition information of multiple functional partitions of the casting;

[0100] Step S620: Based on the partition information, obtain the partition process constraints corresponding to each functional partition;

[0101] Step S630: Combine the process constraints corresponding to each functional partition to generate process constraints.

[0102] It should be noted that functional zones are relatively independent regions within a casting, defined by its structure, function, or process requirements. These zones can be determined based on factors such as the casting's geometry, wall thickness variations, stress concentration areas, or subsequent processing requirements. Zone information is structured data describing the geometric location, boundaries, shape, and relationships between these functional zones and other zones. It can be represented using 3D model data, zone division diagrams, or coordinate ranges. Zone process constraints are specific process requirements, such as temperature, temperature difference, or cooling rate, that each functional zone needs to meet during the cooling process. These constraints can be set based on material properties, expected microstructure, residual stress control targets, or subsequent processing performance requirements.

[0103] The proposed solution obtains the partition information of multiple functional zones in a casting, derives the corresponding process constraints for each functional zone based on this information, and combines these partition process constraints to generate overall process constraints. Therefore, when adjusting the baseline temperature difference relationship based on actual cooling characteristic parameters, the process constraints used are no longer singular and potentially inadequate for local needs, but rather a comprehensive set considering the specific requirements of each functional zone of the casting. This method of generating process constraints based on partition information allows the adjusted temperature difference relationship and the determined preset target temperature difference value to more accurately reflect the actual needs and process objectives of different areas in the cooling process of complex castings. This enables more effective guidance for adjusting the cooling intensity of thick-walled areas, avoiding defects caused by neglecting local differences. This method, combined with a basic approach that relies solely on overall cooling characteristic parameters for adjustment, forms an effective means of refined management of the cooling process of complex structure castings. It can simultaneously meet the requirement of rapid overall passage through the sensitization temperature range and the specific cooling rate and temperature difference constraints of local areas, thus solving the problem of difficulty in simultaneously considering the process objectives of different areas during the cooling process of complex structure castings.

[0104] In one embodiment, for a valve casting having a thick-walled main cavity, a thin-walled guide sleeve, and a sharp inner radius connecting area between them, the casting can be divided into at least three functional zones: a thick-walled main cavity zone, a thin-walled guide sleeve zone, and a connecting area zone. First, the zone information for these three zones is obtained, for example, by reading the three-dimensional CAD model data of the casting to identify and extract the geometric boundaries and volume information of each zone. Then, based on this zone information, the corresponding process constraints for each functional zone are obtained. For example, based on material properties and the requirement to avoid sensitization, minimum cooling rate constraints are set for the thick-walled main cavity zone and the thin-walled guide sleeve zone within a specific temperature range; based on the requirement to avoid thermal fatigue cracks, maximum cooling rate constraints are set for the thick-walled main cavity zone at high temperatures; based on the requirement to avoid residual stress concentration and microcracks, temperature difference constraints or cooling rate change rate constraints are set for the connecting area zone within the phase transition temperature range. Finally, the process constraints corresponding to these three functional zones are combined to generate overall process constraints.

[0105] In one embodiment, a priority rule is used to set the stress constraints of the connection area as the highest priority; alternatively, a weighted average method can be used to integrate cooling rate constraints by assigning different weights to each partition based on its volume or importance; or an optimization algorithm can be used to obtain an overall cooling strategy that satisfies or optimally approximates the constraints of all partitions. This combined set of process constraints is then used to adjust the baseline temperature difference relationship based on actual cooling characteristic parameters, thereby determining a preset target temperature difference value that can guide the precise cooling of thick-walled regions.

[0106] See Figure 7 , Figure 7 This is a flowchart illustrating the process of obtaining the partitioning process constraints corresponding to each functional partition according to one embodiment of this application. The step S630, which obtains the partitioning process constraints corresponding to each functional partition based on the partitioning information, includes, but is not limited to, steps S710 to S740, which will be described in detail below.

[0107] Step S710: Obtain the initial partitioning process constraints for each functional partition and the adjacent functional partition pairs among multiple functional partitions;

[0108] Step S720: In the event of a conflict between the initial partitioning process constraints of adjacent functional partition pairs, determine the transition region at the boundary of adjacent functional partition pairs.

[0109] Step S730: Based on the initial partitioning process constraints, generate the transition process constraints for the transition region;

[0110] Step S740: Based on the transition process constraints and the transition region, obtain the partition process constraints corresponding to each functional partition.

[0111] It should be noted that by obtaining the initial process constraints of each functional zone and adjacent functional zone pairs among multiple functional zones, regions where process constraint conflicts may exist are identified. In cases where conflicts exist between the initial process constraints of adjacent functional zone pairs, a transition region at the boundary of the adjacent functional zone pairs is further determined; this region represents the most significant mutual influence between adjacent zones. Then, based on the initial process constraints, transition process constraints for the transition region are generated. These transition constraints aim to coordinate the different requirements of adjacent zones and achieve a smooth transition. Finally, based on the transition process constraints and the transition region, the process constraints corresponding to each functional zone are obtained. After considering the special characteristics of the transition region and introducing coordinating transition constraints, the original process constraints are modified or supplemented. In this way, the embodiments of this application can more precisely handle the mutual influence between adjacent functional zones in complex casting structures, especially in boundary regions where process constraints conflict, avoiding unreasonable situations that may result from simply applying a single zone constraint. This optimization of the zoned process constraints makes the overall process constraints generated by combining the constraints of each zone more accurate and reasonable. This allows for more effective guidance in adjusting the baseline temperature difference relationship, generating an adjusted temperature difference relationship that is more adapted to the actual cooling process. It solves the problem of ignoring the influence of adjacent zones when directly obtaining the zoned process constraints based on the zoned information, and improves the accuracy and reliability of the overall cooling control scheme.

[0112] In one embodiment, the initial partitioning process constraints for the thick-walled main cavity and the thin-walled guide sleeve are obtained. Based on the wall thickness and material properties of the thick-walled main cavity, its initial constraint is determined to be slow cooling to avoid stress concentration. Based on the wall thickness and material properties of the thin-walled guide sleeve, its initial constraint is determined to be a faster cooling rate under natural air cooling. Simultaneously, the thick-walled main cavity and the thin-walled guide sleeve are identified as forming an adjacent functional partition pair. Detection reveals a conflict between the two initial constraints of slow cooling and faster cooling at the interface. In this case, a transition region at the interface between the thick-walled main cavity and the thin-walled guide sleeve is determined. For example, this region may include the inner radius of the connection and a certain range nearby. Based on the initial partitioning process constraints of the thick-walled main cavity and the thin-walled guide sleeve, transition process constraints for the transition region are generated. For example, through simulation calculations or consulting empirical data, it is determined that the cooling rate of the transition region should be between slow cooling and faster cooling, and may gradually change with distance from the center point of the interface. Finally, based on the generated transition process constraints and the determined transition region, the partition process constraints corresponding to each functional partition are obtained. For example, the generated transition process constraints are applied in the transition region, while the initial partition process constraints are applied in the parts far from the transition region. Alternatively, the transition constraints can be smoothly integrated into the constraints of adjacent partitions to form the final partition process constraints that take into account the influence of adjacent partitions.

[0113] In one embodiment, the partitioned process constraints include at least one cooling rate constraint and at least one temperature difference constraint.

[0114] It should be noted that cooling rate constraint refers to the limitation set on the rate of temperature decrease of a specific functional area of ​​a casting within a specific temperature range. Specifically, this can be achieved by setting an upper or lower limit for temperature change over time. For example, limiting the temperature drop per minute of a certain area from high temperature to medium temperature to no more than a certain value, or requiring its cooling rate to be no less than a certain value. The purpose is to control the microstructure transformation process of that functional area or to avoid defects caused by excessively fast or slow cooling. Temperature difference constraint is the limitation set on the temperature difference between different functional areas of a casting or between different locations within the same functional area. This can be achieved by setting the maximum allowable temperature difference between adjacent functional areas at any given time. For example, limiting the temperature difference between thick-walled and thin-walled areas to no more than a certain value, or limiting the maximum temperature difference within a certain area to no more than a certain value. The purpose is to control the thermal stress during the cooling process of the casting and to avoid deformation or cracking caused by excessive temperature difference.

[0115] See Figure 8 , Figure 8This is a schematic flowchart illustrating the process of obtaining actual cooling characteristic parameters according to an embodiment of this application. Regarding step S330, which determines the actual cooling characteristic parameters based on the first series of temperature information and the second series of temperature information, this includes, but is not limited to, steps S810 to S830, which will be described in detail below.

[0116] Step S810: Calculate the series of actual temperature differences between the first series of temperature information and the second series of temperature information;

[0117] Step S820: Based on the series of actual temperature difference values, determine the decay characteristic parameters of the series of actual temperature difference values ​​over time;

[0118] Step S830: Obtain the actual cooling characteristic parameters based on the attenuation characteristic parameters.

[0119] It should be noted that by calculating a series of actual temperature differences between the thick-walled and thin-walled regions at different time points, a data sequence reflecting the dynamic changes in the internal temperature distribution of the casting was obtained. Since the temperature difference over time is directly related to the heat loss rate and internal heat conduction efficiency of the casting, analyzing this series of actual temperature difference values ​​can determine its decay characteristic parameters over time. These decay characteristic parameters capture the dynamic characteristics of the casting's heat dissipation capacity and thermal equilibrium process under the current actual cooling environment. Based on these decay characteristic parameters, which accurately reflect the dynamic cooling process, more precise actual cooling characteristic parameters can be obtained. Compared to relying solely on a single time point temperature difference or a preset model to determine cooling characteristic parameters, this embodiment analyzes the entire decay process of the temperature difference, enabling a more comprehensive and accurate assessment of the casting's current actual cooling state. Applying the actual cooling characteristic parameters obtained through this scheme to the step of adjusting the baseline temperature difference relationship based on these parameters allows the adjusted temperature difference relationship to more accurately reflect the actual cooling behavior of the casting, thereby determining a more realistic preset target temperature difference value. This allows the entire gradient cooling control method to better adapt to differences in individual castings and environmental conditions, improving the accuracy and stability of cooling control and helping to solve the problem of inconsistent product quality caused by subtle changes in initial conditions.

[0120] In one embodiment, during a preset cooling phase, for a period of time starting from the casting demolding, a first series of temperature information for the thick-walled region and a second series of temperature information for the thin-walled region are collected at fixed time intervals of 10 seconds. At each collection time point, the temperature difference between the thick-walled region and the thin-walled region is calculated, thereby obtaining a series of actual temperature difference values ​​that change over time. This series of actual temperature difference values ​​is correlated with the corresponding collection time to form a data curve of temperature difference changing over time. A curve fitting method can be used, including using an exponential decay model or a polynomial model, to fit the data curve, thereby determining the parameters describing the temperature difference decay trend, including the exponential decay constant or polynomial coefficients. These parameters are the decay characteristic parameters of the series of actual temperature difference values ​​changing over time. Based on the determined decay characteristic parameters, they can be converted into parameters characterizing the actual cooling capacity of the casting through a preset lookup table, empirical formula, or physical model.

[0121] It is worth noting that by calculating and analyzing the decay characteristics of the actual temperature difference between the thick-walled and thin-walled regions over time, the dynamic heat dissipation capacity and thermal balance process of the casting under actual cooling conditions can be reflected more accurately. This allows for more effective control of the temperature difference between the thick-walled and thin-walled regions, reduction of residual stress, and improvement of product quality stability.

[0122] See Figure 9 , Figure 9 This is a schematic diagram of a gradient cooling control system for valve castings according to an embodiment of this application. The gradient cooling control system 900 for valve castings includes:

[0123] The acquisition module 910 is used to acquire first temperature information and second temperature information, wherein the first temperature information represents the temperature information of the thick-walled region of the casting, and the second temperature information represents the temperature information of the thin-walled region of the casting.

[0124] The calculation module 920 is used to calculate the actual temperature difference value based on the first temperature information and the second temperature information.

[0125] The generation module 930 is used to generate control adjustment quantities based on the actual temperature difference value and the preset target temperature difference value;

[0126] The adjustment module 940 adjusts the cooling intensity of the thick-walled region according to the control adjustment amount, the actual temperature difference value, and the preset target temperature difference value.

[0127] It should be noted that the information interaction and execution process between the above modules are based on the same concept as the method embodiments of this application. For details on their specific functions and technical effects, please refer to the method embodiments section, which will not be repeated here.

[0128] It will be understood by those skilled in the art that all or some of the steps and systems in the methods disclosed above can be implemented as software, firmware, hardware, and suitable combinations thereof. Some or all of the physical components can be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on a computer-readable medium, which can include computer storage media (or non-transitory media) and communication media (or transient media). As is known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and is accessible to a computer. Furthermore, as is known to those skilled in the art, communication media typically include computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

[0129] The foregoing has provided a detailed description of the preferred embodiments of this application. However, this application is not limited to the above-described embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of this application. All such equivalent modifications or substitutions are included within the scope defined in this application.

Claims

1. A gradient cooling control method for valve castings, applied to castings, characterized in that, include: Acquire first temperature information and second temperature information, wherein the first temperature information represents the temperature information of the thick-walled region of the casting, and the second temperature information represents the temperature information of the thin-walled region of the casting. Based on the first temperature information and the second temperature information, the actual temperature difference value is obtained; Based on the actual temperature difference and the preset target temperature difference, a control adjustment amount is generated; The cooling intensity of the thick-walled region is adjusted according to the control adjustment amount, the actual temperature difference value, and the preset target temperature difference value. The preset target temperature difference value is obtained through the following steps: Obtain a reference temperature difference relationship, wherein the reference temperature difference relationship characterizes the relationship of the thermophysical properties of the reference material batch; During the preset cooling phase, a first series of temperature information for the thick-walled region and a second series of temperature information for the thin-walled region of the casting are acquired. Based on the first series of temperature information and the second series of temperature information, the actual cooling characteristic parameters are determined. The reference temperature difference relationship is adjusted based on the actual cooling characteristic parameters to generate the adjusted temperature difference relationship; The preset target temperature difference value is determined based on the preset cooling stage and the adjusted temperature difference relationship.

2. The method according to claim 1, characterized in that, The step of obtaining the actual temperature difference value based on the first temperature information and the second temperature information includes: Based on the second temperature information and the preset reference temperature correspondence, the first predicted temperature information is determined, wherein the preset reference temperature correspondence characterizes the temperature relationship between the thick-walled region and the thin-walled region of the casting under natural cooling conditions; Based on the first predicted temperature information and the first temperature information, the measurement deviation value is obtained; The first temperature information is corrected based on the measurement deviation value to obtain the corrected first temperature information; Based on the corrected first temperature information and the second temperature information, the actual temperature difference value is obtained.

3. The method according to claim 1, characterized in that, The determination of actual cooling characteristic parameters based on the first series of temperature information and the second series of temperature information includes: Based on the second series of temperature information, environmental heat dissipation parameters are obtained, wherein the environmental heat dissipation parameters are parameters that characterize the local environmental heat dissipation conditions of the casting. Based on the first series of temperature information and the second series of temperature information, intermediate characteristic parameters are obtained; The actual cooling characteristic parameters are determined based on the environmental heat dissipation parameters and the intermediate characteristic parameters.

4. The method according to claim 1, characterized in that, The step of adjusting the reference temperature difference relationship based on the actual cooling characteristic parameters to generate the adjusted temperature difference relationship includes: Obtain process constraints, wherein the process constraints characterize the conditions of multiple process target boundaries during the cooling process of the casting; The reference temperature difference relationship is adjusted based on the actual cooling characteristic parameters and the process constraints to generate the adjusted temperature difference relationship.

5. The method according to claim 4, characterized in that, The process constraints are obtained through the following steps: Obtain the partition information of multiple functional partitions of the casting; Based on the partition information, the partition process constraints corresponding to each functional partition are obtained; The process constraints are generated by combining the process constraints corresponding to each functional partition.

6. The method according to claim 5, characterized in that, The step of obtaining the partitioning process constraints corresponding to each functional partition based on the partitioning information includes: Obtain the initial partitioning process constraints for each of the functional partitions and the pairs of adjacent functional partitions among the multiple functional partitions; In the event of a conflict between the initial partitioning process constraints corresponding to the adjacent functional partition pairs, a transition region at the boundary of the adjacent functional partition pairs is determined. Based on the initial partitioning process constraints, the transition process constraints for the transition region are generated. Based on the transition process constraints and the transition region, the partition process constraints corresponding to each functional partition are obtained.

7. The method according to claim 5, characterized in that, The partitioned process constraints include at least one cooling rate constraint and at least one temperature difference constraint.

8. The method according to claim 1, characterized in that, The determination of actual cooling characteristic parameters based on the first series of temperature information and the second series of temperature information includes: Calculate the series of actual temperature differences between the first series of temperature information and the second series of temperature information; Based on the series of actual temperature difference values, determine the decay characteristic parameters of the series of actual temperature difference values ​​over time; The actual cooling characteristic parameters are obtained based on the attenuation characteristic parameters.

9. A gradient cooling control system for valve castings, characterized in that, include: The acquisition module is used to acquire first temperature information and second temperature information, wherein the first temperature information represents the temperature information of the thick-walled region of the casting, and the second temperature information represents the temperature information of the thin-walled region of the casting. The calculation module is used to calculate the actual temperature difference value based on the first temperature information and the second temperature information. The generation module is used to generate a control adjustment amount based on the actual temperature difference value and the preset target temperature difference value; The adjustment module adjusts the cooling intensity of the thick-walled region according to the control adjustment amount, the actual temperature difference value, and the preset target temperature difference value; The preset target temperature difference value is obtained through the following steps: Obtain a reference temperature difference relationship, wherein the reference temperature difference relationship characterizes the relationship of the thermophysical properties of the reference material batch; During the preset cooling phase, a first series of temperature information for the thick-walled region and a second series of temperature information for the thin-walled region of the casting are acquired. Based on the first series of temperature information and the second series of temperature information, the actual cooling characteristic parameters are determined. The reference temperature difference relationship is adjusted based on the actual cooling characteristic parameters to generate the adjusted temperature difference relationship; The preset target temperature difference value is determined based on the preset cooling stage and the adjusted temperature difference relationship.

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