A method and device for adaptive optimization of pressure curve of low-pressure casting of ball valve body

Abstract

The application is suitable for the technical field of parameter optimization, and particularly relates to a ball valve body low-pressure casting pressure curve self-adaptive optimization method and device.The method comprises the following steps: obtaining condensate data corresponding to a main load-bearing structure area of the valve body in a first low-pressure casting stage and thermal node gradient distribution characteristics in a second low-pressure casting stage; determining composite structure data associated with the main load-bearing structure area of the valve body; determining a spatial mapping relationship according to the condensate data, the thermal node gradient distribution characteristics and the composite structure data; determining liquid feeding data of a composite structure transition area based on the expansion characteristics of the valve body; constructing phase change pressure data according to the sealing performance of the valve body under pressure and the viscosity-temperature characteristics of the molten metal and according to the casting process; and determining optimization data based on the spatial mapping relationship, the liquid feeding data and the phase change pressure data.The ball valve body low-pressure casting pressure curve self-adaptive optimization method provided by the application reduces the problems of spatter and gas entrapment caused by high pressure in the thin-wall area and shrinkage caused by low pressure in the thick-wall area.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of parameter optimization, and particularly relates to a ball valve body low-pressure casting pressure curve self-adaptive optimization method and device. BACKGROUND

[0002] The ball valve is a valve with a ball as a core opening and closing element, mainly used for controlling the on-off or flow regulation of fluid (such as liquid, gas, slurry, etc.) in a pipeline. The ball valve body is the core pressure-bearing component of the ball valve, serving as the shell of internal structures such as the ball, valve seat, and sealing assembly. Its design determines the sealing performance and pressure-bearing capacity of the valve. The casting method of the valve body is usually realized through low-pressure casting technology. The core of low-pressure casting is to use low-pressure gas to press the molten metal in the holding furnace into the mold cavity through a riser pipe, and maintain the pressure until the molten metal completely solidifies to obtain a casting.

[0003] The low-pressure casting in the related art only uses a whole pressure curve for control implementation. When parameters are set, the fixed whole pressure curve can only compromise the parameters, so that the thin-walled area produces spatter and gas entrapment due to excessive pressure, or the thick-walled area forms shrinkage due to insufficient pressure, resulting in low reliability of the ball valve. SUMMARY

[0004] The ball valve body low-pressure casting pressure curve self-adaptive optimization method and device provided by the embodiments of the application can solve the problem of spatter and gas entrapment in the thin-walled area due to excessive pressure, or shrinkage in the thick-walled area due to insufficient pressure caused by a fixed pressure curve.

[0005] In a first aspect, the embodiments of the application provide a ball valve body low-pressure casting pressure curve self-adaptive optimization method, comprising:

[0006] Obtaining solidification defect data corresponding to a main load-bearing structure area of a valve body in a first low-pressure casting stage and thermal node gradient distribution characteristics in a second low-pressure casting stage; wherein the solidification defect data includes a pressure spectrum and a solidification defect spectrum, and the thermal node gradient distribution characteristics are used to reflect the distribution of the temperature change rate of the valve body during the solidification process;

[0007] Determining composite structure data associated with the main load-bearing structure area of the valve body; wherein the composite structure data is used to reflect the morphology of the composite structure transition area, and the composite structure transition area includes a flange flow channel intersection and a valve stem mounting boss;

[0008] Determining a spatial mapping relationship according to the solidification defect data, the thermal node gradient distribution characteristics, and the composite structure data; wherein the spatial mapping relationship is used to indicate the correspondence between the defect concentration area and the composite structure transition area;

[0009] determine liquid feeding data of the composite structure transition region based on the expansion characteristics of the valve body; wherein the liquid feeding data comprises pulse boosting parameters of the thin-wall intersection area of the flange runner intersection and pressure maintaining strength parameters of the thick-wall boss area of the valve rod mounting boss;

[0010] construct phase transition pressure data according to the casting process by the pressure-bearing sealing performance of the valve body and the viscosity-temperature characteristics of the molten metal; wherein the phase transition pressure data is used to indicate the dynamic pressure threshold before solidification of the valve body, and the casting process comprises a pressure boosting process, a crystallization process and a pressure releasing process;

[0011] determine optimization data based on the spatial mapping relationship, the liquid feeding data and the phase transition pressure data; wherein the optimization data is used to indicate the optimized low-pressure casting pressure curve of the valve body.

[0012] The ball valve body low-pressure casting pressure curve adaptive optimization method provided by the application obtains the solidification defect data corresponding to the main load-bearing structure region of the valve body in the first low-pressure casting stage and the thermal gradient distribution characteristics in the second low-pressure casting stage, which can improve the defect recognition accuracy of the main load-bearing structure region of the valve body in the casting process. By determining the composite structure data associated with the main load-bearing structure region of the valve body, the structural characteristics of the valve body in the casting process can be more accurately reflected. Determining the composite structure data associated with the main load-bearing structure region of the valve body, determining the spatial mapping relationship according to the solidification defect data, the thermal gradient distribution characteristics and the composite structure data can provide a basis for the subsequent determination of the liquid feeding data and the phase transition pressure data. Based on the expansion characteristics of the valve body, the liquid feeding data of the composite structure transition region is determined, the phase transition pressure data is constructed according to the pressure-bearing sealing performance of the valve body and the viscosity-temperature characteristics of the molten metal, and the optimization data is determined based on the spatial mapping relationship, the liquid feeding data and the phase transition pressure data. The control of the local region in the casting process can be improved, and the defects caused by the fixed pressure curve in the traditional low-pressure casting method can be avoided, thereby effectively reducing the spatter and gas problems caused by the too high pressure in the thin-wall area and the shrinkage problems caused by the insufficient pressure in the thick-wall area, improving the casting quality and use reliability of the ball valve body.

[0013] In a second aspect, the embodiments of the application provide a ball valve body low-pressure casting pressure curve adaptive optimization system, comprising:

[0014] An acquisition unit is configured to acquire solidification defect data corresponding to a main load-bearing structure region of a valve body in a first low-pressure casting stage and thermal gradient distribution characteristics in a second low-pressure casting stage; wherein the solidification defect data comprises a pressure spectrum and a solidification defect spectrum, and the thermal gradient distribution characteristics are used to reflect the distribution of temperature change rate of the valve body during solidification;

[0015] The first determining unit is configured to determine composite structure data associated with the main load-bearing structure region of the valve body; the composite structure data is used to reflect the morphology of a composite structure transition region, and the composite structure transition region includes a flange runner intersection and a valve rod mounting boss;

[0016] The second determining unit is configured to determine a spatial mapping relationship according to the defect cluster data, the thermal gradient distribution characteristics, and the composite structure data; the spatial mapping relationship is used to indicate the correspondence between the defect cluster region and the composite structure transition region.

[0017] The third determining unit is configured to determine liquid feeding data of the composite structure transition region based on the expansion characteristics of the valve body; the liquid feeding data includes pulse pressurization parameters of a thin-wall intersection region of the flange runner intersection and pressure maintaining strength parameters of a thick-wall boss region of the valve rod mounting boss.

[0018] The constructing unit is configured to construct phase transition pressure data by combining the valve body pressure sealing performance and the metal liquid viscosity-temperature characteristics, and according to a casting process; the phase transition pressure data is used to indicate a dynamic pressure threshold before solidification of the valve body; the casting process includes a pressurization process, a crystallization process, and a depressurization process.

[0019] The result unit is configured to determine optimization data based on the spatial mapping relationship, the liquid feeding data, and the phase transition pressure data; the optimization data is used to indicate an optimized low-pressure casting pressure curve of the valve body.

[0020] In a third aspect, an embodiment of the present application provides a ball valve body low-pressure casting pressure curve self-adaptive optimization device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, when the computer program is executed by the processor, the method of any one of the above first aspect is implemented.

[0021] In a fourth aspect, an embodiment of the present application provides a computer program product, when the computer program product is executed on a ball valve body low-pressure casting pressure curve self-adaptive optimization device, the ball valve body low-pressure casting pressure curve self-adaptive optimization device executes the ball valve body low-pressure casting pressure curve self-adaptive optimization method of any one of the above first aspect.

[0022] It can be understood that the beneficial effects of the above-mentioned second aspect to fourth aspect can be referred to the related description in the above-mentioned first aspect, which will not be repeated here. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description only constitute some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort.

[0024] Figure 1 is a schematic diagram of the overall structure of the ball valve provided by an embodiment of the present application;

[0025] Figure 2 is a sectional view of the ball valve provided by an embodiment of the present application;

[0026] Figure 3 is a flowchart of the ball valve body low-pressure casting pressure curve self-adaptive optimization method provided by an embodiment of the present application;

[0027] Figure 4 is a flowchart of the implementation of step S300 in the ball valve body low-pressure casting pressure curve self-adaptive optimization method provided by an embodiment of the present application;

[0028] Figure 5 is a flowchart of the implementation of step S400 in the ball valve body low-pressure casting pressure curve self-adaptive optimization method provided by an embodiment of the present application;

[0029] Figure 6 is another flowchart of the implementation of step S400 in the ball valve body low-pressure casting pressure curve self-adaptive optimization method provided by an embodiment of the present application;

[0030] Figure 7 is a flowchart of the implementation of step S500 in the ball valve body low-pressure casting pressure curve self-adaptive optimization method provided by an embodiment of the present application;

[0031] Figure 8 is a flowchart of the implementation of step S600 in the ball valve body low-pressure casting pressure curve self-adaptive optimization method provided by an embodiment of the present application;

[0032] Figure 9 is a structural diagram of the ball valve body low-pressure casting pressure curve self-adaptive optimization system provided by an embodiment of the present application;

[0033] Figure 10 is a structural diagram of the ball valve body low-pressure casting pressure curve self-adaptive optimization device provided by an embodiment of the present application.

[0034] In the drawings, various reference signs represent:

[0035] 100. Ball valve; 10. Valve body; 20. Hand wheel; 30. Limiting block; 40. Bolt; 50. Fixed housing; 60. Threaded rod; 11. Connecting hole. DETAILED DESCRIPTION

[0036] In the following description, for purposes of explanation and not limitation, specific details are set forth such as particular architectures, techniques, etc. in order to provide a thorough understanding of the embodiments of the present application. However, it will be apparent to those skilled in the art that the present application can be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known methods, devices, circuits, and

[0037] It is to be understood that the terminology "includes", "has", "holds", "contains" or variants thereof, when utilized within the present specification and claims, denotes the presence of the stated feature but not the exclusion after the stated feature or addition of further features.

[0038] It is also to be understood that the terminology "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items, and that the term "at least one of" followed by a list of two or more items means any single one of the items in the list individually, as well as any combination of two or more of the items in the list.

[0039] As used in the present specification and claims, the term "if" can be interpreted as meaning "when" or "upon" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrase "if it is determined" or "if [a described condition or event] is detected" can be interpreted to mean "upon determining" or "in response to determining" or "upon detecting [the described condition or event]" or "in response to detecting [the described condition or event]", depending on the context.

[0040] In addition, the terms "first", "second", "third", etc. as used in the description of the specification and the appended claims are only used to distinguish descriptions, and cannot be understood as indicating or implying relative importance.

[0041] Reference within this specification to "one embodiment" or "an embodiment" or "some embodiments" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The appearances of the phrase "in one embodiment" or "in some embodiments" in various places in the specification are not necessarily all referring to the same embodiment, however, are meant to signify that "one or more, but not all" embodiments include the feature, structure, or characteristic. The terms "including," "comprising," "having," and "fronts" and variations thereof do not have a limiting meaning when used in connection with a term or phrase and mean "including, but not limited to."

[0042] At present, the industry generally adopts low-pressure casting process to produce ball valve body, and the process can greatly reduce defects such as gas entrapment and insufficient pouring compared with traditional gravity casting by introducing low-pressure gas (0.02-0.15 MPa) into the sealed metal liquid furnace to push the metal liquid to fill the mold smoothly, which is the mainstream technology for valve body casting; but in the long-term production practice, the research and development team found that the low-pressure casting process always cannot break through the bottleneck of high defect rate in the key area of the valve body, and the root cause of this problem is mainly due to the fixed overall pressure curve control.

[0043] Low-pressure casting technology is mainly applied to simple structure castings (such as aluminum alloy hub, small pipe fittings), and the wall thickness of such castings is uniform and has no obvious "hot spot area" (i.e. thick wall parts with slow heat dissipation and long solidification time). Therefore, technicians form the thought of "overall pressure control", and set a fixed "time-pressure" curve for a certain specification of valve body, which covers the whole process from "metal liquid lifting (from the furnace to the mold) → filling (filling the cavity) → pressure maintaining (supplementing solidification shrinkage) → pressure relief (opening the mold to take out the piece)". The core reason of using this way is two points: first, the control system of the early low-pressure casting machine has low precision and only supports single pressure time output, which cannot realize "regional dynamic pressure regulation"; second, the overall pressure curve is simple to debug, and technicians only need to find a set of parameters that can more or less adapt to most areas through 1-2 rounds of trial and error, and then mass production without analyzing the structural differences of the valve body. This mode is acceptable when dealing with simple castings, but when applied to complex ball valve body, the contradiction begins to emerge. Because the ball valve body is not a uniform wall thickness piece, when setting parameters, the fixed overall pressure curve can only compromise the parameters, which will have a high probability of causing spatter and gas entrapment in the thin wall area due to high pressure or shrinkage in the thick wall area due to insufficient pressure, resulting in low reliability of the ball valve.

[0044] To solve the above problems, the embodiments of the present application provide a low-pressure casting pressure curve self-adaptive optimization method and equipment for ball valve body.

[0045] In the method, the ball valve body low-pressure casting pressure curve self-adaptive optimization method provided by the application obtains the shrinkage data corresponding to the main load-bearing structure area of the valve body in the first low-pressure casting stage and the thermal gradient distribution characteristics in the second low-pressure casting stage, which can improve the defect identification accuracy of the main load-bearing structure area of the valve body in the casting process. By determining the composite structure data associated with the main load-bearing structure area of the valve body, the structural characteristics of the valve body in the casting process can be more accurately reflected. Determining the composite structure data associated with the main load-bearing structure area of the valve body, determining the spatial mapping relationship according to the shrinkage data, the thermal gradient distribution characteristics and the composite structure data can provide a basis for subsequent determination of liquid feeding and phase change pressure data. Based on the expansion characteristics of the valve body, the liquid feeding data of the composite structure transition area is determined, the sealing performance of the valve body under pressure and the viscosity-temperature characteristics of the molten metal are determined, and the phase change pressure data is constructed according to the casting process. Based on the spatial mapping relationship, the liquid feeding data and the phase change pressure data, the optimization data is determined, which can improve the control of local areas in the casting process and avoid defects caused by fixed pressure curve in traditional low-pressure casting method, thereby effectively avoiding the spatter and gas problem caused by high pressure in the thin-walled area and the shrinkage problem caused by insufficient pressure in the thick-walled area, improving the casting quality and use reliability of the ball valve body.

[0046] The ball valve body low-pressure casting pressure curve self-adaptive optimization method provided by the application can be applied to a ball valve body low-pressure casting pressure curve self-adaptive optimization device. At this time, the ball valve body low-pressure casting pressure curve self-adaptive optimization device is the execution subject of the ball valve body low-pressure casting pressure curve self-adaptive optimization method provided by the application. The specific type of the ball valve body low-pressure casting pressure curve self-adaptive optimization device is not limited in the application.

[0047] Exemplarily, Figure 1 The overall structure of the ball valve is shown, Figure 2A cross-sectional view of the ball valve is shown. The ball valve 100 includes a valve body 10, a hand wheel 20, a limiting block 30, a bolt 40, a fixed housing 50, a threaded rod 60, and a connecting hole 11. The valve body 10 is the main part of the ball valve 100, with a specific internal flow passage for controlling the on-off of fluid. The threaded rod 60 is connected with the hand wheel 20; the threaded rod 60 is provided through the center hole of the fixed housing 50, the limiting block 30 is sleeved (or can be clamped) on the middle part of the threaded rod 60, and the limiting block 30 forms a circumferential limiting fit with the inner wall of the fixed housing 50, limiting the circumferential rotation of the threaded rod 60 and allowing only axial movement; the hand wheel 20 is directly driven to rotate the threaded rod 60; the threaded rod 60 is connected with the valve body 10, and by rotating the hand wheel 20, the valve core in the valve body can be driven to move, thereby changing the on-off state of the flow passage. The limiting block 30 is arranged on the valve body 10, which is used to limit the rotation angle of the hand wheel 20, preventing damage caused by excessive rotation. The bolt 40 is used to fix and install the ball valve 100 on the pipeline or other equipment, ensuring the stability and reliability of the ball valve. The connecting hole 11 is arranged on the valve body 10, which is used to connect with other pipelines or components to realize the transmission and control of fluid. The ball valve body low-pressure casting pressure curve self-adaptive optimization device is in communication connection with the casting equipment; the ball valve body low-pressure casting pressure curve self-adaptive optimization device can be a tablet computer, a notebook computer, a netbook, a desktop computer, a smart large screen, a smart television, a computer, a laptop computer, a handheld computing device, etc.

[0048] In order to better understand the ball valve body low-pressure casting pressure curve self-adaptive optimization method provided by the embodiments of the present application, the specific implementation process of the ball valve body low-pressure casting pressure curve self-adaptive optimization method provided by the embodiments of the present application will be exemplarily introduced below.

[0049] Figure 3 A schematic flow chart of the ball valve body low-pressure casting pressure curve self-adaptive optimization method provided by the embodiments of the present application is shown, and the ball valve body low-pressure casting pressure curve self-adaptive optimization method comprises:

[0050] S100, obtaining the solidification defect data corresponding to the valve body main load-bearing structure area in the first low-pressure casting stage and the thermal gradient distribution characteristics in the second low-pressure casting stage; wherein the solidification defect data includes a pressure spectrum and a solidification defect spectrum, and the thermal gradient distribution characteristics are used to reflect the distribution of the temperature change rate of the valve body in the solidification process.

[0051] It can be understood that the first low-pressure casting stage refers to the stage in which the molten metal fills the valve body main load-bearing structure area and begins to solidify initially; the second low-pressure casting stage refers to the stage in which the main load-bearing structure area is from initial solidification to complete solidification; the valve body main load-bearing structure area refers to the core part of the valve body that bears the main working load (for example, the fluid passage pressure bearing wall or the force column connected with the actuator); the solidification defect data is a data set reflecting the correlation between the casting defects of the area and the pressure.

[0052] Exemplarily, obtaining the shrinkage data corresponding to the main load-bearing structure region of the valve body in the first low-pressure casting stage can be achieved by simulation, i.e., importing a three-dimensional casting model of the valve body into a casting simulation software (e.g., ProCAST, MAGMAsoft), setting the process parameters of the first low-pressure casting stage (e.g., pouring temperature 680℃, holding pressure 0.6MPa, pouring speed 50mm / s), running the simulation, and then exporting the solidification process data of the main load-bearing structure region of the valve body; screening the solidification shrinkage defect information of the region from the simulation data (e.g., by marking the coordinates of the shrinkage cavity (e.g., X100, Y80, Z50), diameter 3mm, distribution range of shrinkage (e.g., X95-105, Y75-85, Z48-52)), and arranging it into "shrinkage data"; the thermal gradient distribution characteristics in the second low-pressure casting stage are obtained by, i.e., at the beginning of the second low-pressure casting stage (corresponding to 10-30 minutes after the completion of the metal liquid filling in the simulation), collecting the real-time temperature data of each region of the valve body (e.g., collecting 1 time every 5 seconds, a total of 300 groups) through the temperature field monitoring module of the software, and then calculating the temperature gradient of the thermal node based on these data, and finally arranging the thermal gradient distribution characteristics, for example, the thermal gradient of the valve rod mounting boss region is 4℃ / mm, and the thermal gradient of the flange runner intersection is 3.5℃ / mm.

[0053] In one possible implementation, S100, the shrinkage data corresponding to the main load-bearing structure region of the valve body in the first low-pressure casting stage and the thermal gradient distribution characteristics in the second low-pressure casting stage are obtained, including:

[0054] S110, analyzing the solidification shrinkage defect distribution pattern of the main load-bearing structure region of the valve body in the casting simulation result.

[0055] It can be understood that the solidification shrinkage defect distribution pattern refers to the spatial distribution law of shrinkage cavities, shrinkage porosities and other defects in the main load-bearing structure region of the valve body. For example, concentrated in a specific position, distributed in a specific shape;

[0056] Exemplarily, the spatial position of the defect is observed, and then the shape law of the defect is analyzed, and the distribution pattern is obtained according to the shape law; wherein, the spatial position of the defect can be observed by recording whether the defect is concentrated in the connecting part of the main load-bearing structure and the flange, the bottom corner of the main load-bearing structure, etc., and the number of defects at each position is counted (e.g., 8 shrinkage cavities at the connecting part, 5 shrinkage porosities at the bottom corner); the shape law of the defect can be analyzed by measuring the size of the defect (e.g., the diameter of the shrinkage cavity at the connecting part is 2-4mm, and it is spherical; the shrinkage porosity at the bottom corner is net-shaped, and the area is 5-8mm²), and the law of the defect and the structure wall thickness is obtained; finally, the distribution pattern can be determined as that the solidification shrinkage defects of the main load-bearing structure region of the valve body are mainly concentrated in the thick wall part connected with the flange, and the spherical shrinkage cavity is mainly supplemented by the net-shaped shrinkage porosity.

[0057] S120, generating a pressure spectrum and a solidification defect spectrum according to the solidification shrinkage defect distribution pattern.

[0058] It can be understood that the pressure spectrum refers to a graph formed by arranging the pressure values of different positions in the main load-bearing structure area of the valve body in the casting process according to the spatial positions (reflecting the correlation between pressure distribution and defects); and the solidification defect spectrum refers to a visual graph formed by arranging the types (shrinkage holes / shrinkage porosity), positions, sizes, and severity of solidification shrinkage defects according to spatial coordinates (intuitively displaying the defect distribution).

[0059] Exemplarily, generating the pressure spectrum can be to derive the real-time pressure data of each coordinate point in the main load-bearing structure area of the valve body in the first low-pressure casting stage from the casting simulation software, to screen out the coordinate points in the defect concentrated area in the solidification shrinkage defect distribution pattern, to extract the pressure values of these points, to draw a pressure distribution curve with spatial coordinates (X, Y) as the horizontal axis and pressure values (MPa) as the vertical axis, to mark the pressure anomaly section with a pressure lower than 0.6 MPa, and to form the pressure spectrum. Generating the solidification defect spectrum can be to establish a defect type (shrinkage hole / shrinkage porosity), spatial coordinate (X, Y, Z), size (diameter / area), and severity level (light / medium / heavy, divided by size: diameter less than 2 mm is light, 2 to 4 mm is medium, and greater than 4 mm is heavy), and then to mark the defect position (shrinkage hole is marked with a red dot, and shrinkage porosity is marked with an orange mesh ring) on the graph according to the two-dimensional section view of the main load-bearing structure of the valve body, and to mark the defect size and severity level beside the graph, to arrange the marked section view into a series of graphs according to the Z-axis height, and to form the solidification defect spectrum.

[0060] S130, collecting the solidification temperature field, and calculating the temperature change rate spatial distribution according to the solidification temperature field to determine the thermal gradient distribution characteristics.

[0061] It can be understood that the solidification temperature field refers to the temperature spatial distribution field (such as different coordinate points corresponding to different temperatures) formed by the temperature of all positions inside the valve body at a certain moment in the second low-pressure casting stage; and the temperature change rate spatial distribution refers to the distribution of the temperature change amount (℃ / s) per unit time at different positions in space.

[0062] Exemplarily, the solidification temperature field can be collected by pre-installing 20 K-type thermocouples (with a spacing of 5 mm between each position) at the main load-bearing structure area of the valve body mold, the flange flow channel intersection, or / and the valve stem mounting boss, and connecting a data acquisition instrument (such as Agilent 34970A), starting the second low-pressure casting stage (after the metal liquid completes filling), setting the acquisition frequency of the data acquisition instrument to 10 seconds / time, and continuously collecting for 30 minutes (a total of 180 groups of data), recording the position coordinates of each thermocouple (such as thermocouple 1: X80, Y60, Z40; thermocouple 2: X85, Y60, Z40) and the temperature value at the corresponding time, sorting out the solidification temperature field data, and obtaining the collected solidification temperature field according to the solidification temperature field data; the temperature change rate spatial distribution can be calculated by calculating the temperature difference of two adjacent time points for each thermocouple (such as a temperature difference of -20°C between t1 time point temperature 600°C and t2 time point temperature 580°C), and then dividing by the time interval (10 seconds) to obtain the temperature change rate of the position (-2°C / s), and then taking the valve body spatial coordinates (X, Y) as the horizontal axis and the temperature change rate (°C / s) as the vertical axis to draw a rate distribution thermodynamic map (red represents a slow rate < -1°C / s, and blue represents a fast rate > -3°C / s), forming a temperature change rate spatial distribution map; wherein, the rate distribution thermodynamic map can be drawn by communicating and connecting the low-pressure casting pressure curve self-adaptive optimization equipment of the ball valve body and the Origin software.

[0063] In this way, the heat check area can be accurately positioned, providing a direct basis for subsequent identification of defects caused by temperature abnormalities, and the heat check gradient data can also reflect the influence of the structure on cooling.

[0064] S200, determining composite structure data associated with the main load-bearing structure area of the valve body; wherein the composite structure data is used to reflect the morphology of the composite structure transition area, and the composite structure transition area includes the flange flow channel intersection and the valve stem mounting boss.

[0065] Exemplarily, by determining the flange and the internal flow passage features, locating the intersection of the two (the part where the annular structure of the flange connects with the cylindrical structure of the flow passage), and according to the valve stem mounting boss features (the protruding cylindrical structure in the model, with a mounting hole at the top), confirming the connection position with the main load-bearing structure of the valve body (for example, the connection of the bottom of the boss with the upper surface of the main load-bearing structure), the inner diameter of the flange, the diameter of the flow passage, the transition fillet radius at the intersection, the wall thickness at the intersection, the distance from the intersection to the main load-bearing structure, the boss height, the boss bottom diameter, the boss top diameter, the boss top mounting hole diameter, the boss wall thickness, and the like are determined, and the above data are compared to determine the composite structure data.

[0066] In one possible implementation, S200, the composite structure data associated with the main load-bearing structure region of the valve body is determined, including:

[0067] S210, the geometric boundary conditions of the flange flow passage intersection and the valve stem mounting boss in the structural model of the valve body are determined.

[0068] It can be understood that the geometric boundary conditions refer to the key parameters (including boundary coordinates, size ranges, shape features, and connection boundaries with other structures) used to define the geometric shape of the structure in engineering analysis (such as casting simulation and structural mechanics analysis); here, it refers to the geometric parameters of the geometric boundaries of the flange flow passage intersection and the valve stem mounting boss, i.e., the geometric parameters of the outer contour, the inner hole, and the connection surface with other structures of the region.

[0069] Exemplarily, the geometric boundary conditions of the flange flow passage intersection and the valve stem mounting boss in the structural model of the valve body can be determined by opening the structural model of the valve body by using a three-dimensional modeling software (such as SolidWorks or Pro / E), measuring the outer contour size (such as the flange outer diameter, the flow passage width, and the transition fillet radius at the intersection) of the flange flow passage intersection, the inner hole size (such as the flange inner diameter and the flow passage diameter), and the connection surface size (such as the intersection wall thickness and the connection surface size of the intersection with the main load-bearing structure) by using a measurement tool (such as a distance, angle, and area measurement tool), and recording the measurement data; at the same time, the geometric parameters of the valve stem mounting boss are measured, including the boss height, the boss bottom diameter, the boss top diameter, the boss top mounting hole diameter, the boss wall thickness, and the like, and the measurement data are recorded, and the above measurement data are sorted to obtain the geometric boundary conditions of the flange flow passage intersection and the valve stem mounting boss.

[0070] S220, based on the geometric boundary conditions and the main load-bearing structure region of the valve body, the state is determined to obtain the composite structure data.

[0071] Exemplarily, the connection state is determined by comparing the geometric boundary conditions with the main load-bearing structure region through the geometric parameters of the main load-bearing structure region of the valve body, and then the composite structure data is obtained; specifically, the determination of the connection state can be through coordinate comparison to determine that the connection surface at the intersection completely falls on the upper surface of the main load-bearing structure region, which belongs to face-to-face bonding connection, to determine the gradual transition state according to the transition length of the wall thickness of the intersection and the wall thickness of the main load-bearing structure, to determine the center positioning and face covering connection state when the coordinates of the center of the boss bottom and the key stress point coordinates of the main load-bearing structure completely coincide, and the boss connection surface covers the local upper surface of the main load-bearing structure, and to determine the round corner transition (reducing stress concentration) when the transition of the boss wall thickness and the wall thickness of the main load-bearing structure has a round corner, and then the state is formed into composite structure data to supplement the connection information through the state determination, so that the composite structure data is more complete.

[0072] S300, determine the spatial mapping relationship according to the defect data, the thermal gradient distribution characteristics and the composite structure data; wherein the spatial mapping relationship is used to indicate the corresponding relationship between the defect concentration area and the composite structure transition area.

[0073] Exemplarily, according to the defect position coordinates in the defect data, the thermal gradient distribution characteristics in the thermal gradient distribution characteristics and the geometric boundary conditions in the composite structure data, the feature points are positioned in the three-dimensional space, the defect concentration area (such as the shrinkage hole and shrinkage porosity concentration area) is associated with the composite structure transition area (such as the intersection of the flange flow channel and the connection area of the valve rod mounting boss and the main load-bearing structure), and the relative position and spatial relationship between them are determined; wherein this spatial mapping relationship can be realized by marking feature points, drawing connection lines or surfaces in three-dimensional modeling software, or can be automatically calculated and generated through algorithm program; by determining the spatial mapping relationship, the corresponding relationship between the defect concentration area and the composite structure transition area can be determined, which can provide an important basis for subsequent analysis of defect causes and optimization of casting process.

[0074] In one possible implementation, please refer to Figure 4 , S300, determine the spatial mapping relationship according to the defect data, the thermal gradient distribution characteristics and the composite structure data, comprising:

[0075] S310, determine the pressure abnormal data according to the pressure spectrum and the solidification defect spectrum included in the defect data, and determine the temperature mutation area according to the thermal gradient distribution characteristics; wherein the pressure abnormal data is used to indicate the pressure abnormal area.

[0076] Exemplarily, according to the abnormal section determined according to the pressure lower than 0.6 MPa marked in the pressure spectrum and the defect, the pressure abnormal area is determined according to the abnormal section, that is, the area in which the pressure value is lower than the set threshold value in the main bearing structure area of the valve body; at the same time, according to the area with slow rate represented by red in the temperature change rate spatial distribution diagram, the temperature mutation area, that is, the hot spot area, is determined.

[0077] S320, the pressure abnormal area and the temperature mutation area are spatially superimposed to obtain a defect area; wherein the defect area is used to indicate the potential defect concentration area of the valve body in the casting process.

[0078] Exemplarily, the pressure abnormal area and the temperature mutation area are superimposed to determine the overlapping area of the pressure abnormal area and the temperature mutation area in space, and the overlapping area is determined as the defect area, that is, the potential defect concentration area of the valve body in the casting process; in addition, through the defect area, it can be shown that there are problems of insufficient pressure and slow cooling rate in these areas in the casting process.

[0079] S330, the defect area and the form condition reflected by the composite structure data are analyzed to obtain a spatial mapping relationship.

[0080] Exemplarily, the spatial coordinates of the defect area and the geometric boundary conditions of the flange flow channel intersection and the valve rod mounting boss in the composite structure data are compared and analyzed to determine whether the defect area falls within the composite structure transition area or has a direct adjacent relationship with the transition area; at the same time, according to the relative position of the defect area and the composite structure transition area, for example, above, below or side of the intersection, and the relative positional relationship of the defect area and the boss connecting surface, for example, covering the boss connecting surface, having a gap with the boss connecting surface or being adjacent, and according to the corresponding relationship between the size and form of the defect area and the size and form of the composite structure transition area, for example, the ratio of the diameter of the defect area to the diameter of the flow channel, the relationship between the shape of the defect area and the transition fillet shape of the intersection, etc., the spatial mapping relationship is finally obtained to clearly indicate the corresponding relationship between the defect concentration area and the composite structure transition area, providing accurate guidance for subsequent optimization of the casting process.

[0081] In this way, the pressure distribution, temperature change and morphological characteristics of the composite structure in the casting process can be considered comprehensively, so that the potential defect concentration area can be accurately identified, and strong support can be provided for subsequent targeted optimization measures, which not only can improve the casting efficiency, but also can effectively reduce the scrap rate caused by defects, and improve the product quality and overall competitiveness.

[0082] S400, liquid feeding data of the composite structure transition area is determined based on the expansion characteristics of the valve body; wherein the liquid feeding data includes pulse pressurization parameters of the thin-wall intersection area of the flange flow channel intersection and pressure holding strength parameters of the thick-wall boss area of the valve rod mounting boss.

[0083] For example, based on the thermal expansion characteristics of the valve body material during the casting process, the volume change of the composite structure transition area during the solidification stage is analyzed, and then the required liquid metal feeding amount is determined. For the thin-walled intersection area at the intersection of the flange flow channel, due to the complex structure and thin wall thickness of this area, shrinkage and porosity defects are easily generated during solidification; therefore, the solidification sequence and feeding requirement of this area need to be determined through simulation analysis, and then the pulse pressure parameters are set to inject an appropriate amount of liquid metal into this area to fill the gap generated due to solidification shrinkage; the pulse pressure parameters should include the pressure timing, pressure amplitude and pressure frequency, etc., so as to achieve the best feeding effect. For the thick-walled boss area of the valve rod mounting boss, due to the large wall thickness, the solidification time is long, and shrinkage defects are easily generated inside; therefore, appropriate pressure holding strength parameters need to be set to maintain a certain pressure at the late solidification stage to promote the feeding of liquid metal to this area; the pressure holding strength parameters should include the pressure holding start time, pressure holding pressure value and pressure holding duration, etc., so as to enable the area to be fully fed to reduce defect generation.

[0084] In one possible implementation, referring to Figure 5 , S400, determining the liquid feeding data of the composite structure transition area based on the expansion characteristics of the valve body, including:

[0085] S410, determining the metal liquid flow resistance coefficient of the thin-walled intersection area at the intersection of the flange flow channel and the solidification shrinkage compensation amount of the thick-walled boss area of the valve rod mounting boss according to the expansion characteristics.

[0086] It can be understood that the thin-walled intersection area at the intersection of the flange flow channel refers to the area where the flange flow channels intersect and the wall thickness is thin; the thick-walled boss area of the valve rod mounting boss refers to the core area with thick wall thickness in the boss for mounting the valve rod. The metal liquid flow resistance coefficient is a parameter reflecting the degree of hindrance of the metal liquid when flowing in the thin-walled intersection area; the solidification shrinkage compensation amount is the amount of metal liquid that needs to be supplemented due to the volume reduction of the metal liquid when solidifying in the thick-walled boss area.

[0087] For example, according to the expansion characteristic data (such as the volume change value at different temperatures) of the valve body material, a flow channel model of the thin-walled intersection area is established by using a fluid simulation software, the metal liquid temperature, viscosity and expansion characteristic data are input, and the flow resistance coefficient is obtained by simulating the metal liquid flow process; then a three-dimensional model of the thick-walled boss area is established, the volume shrinkage trend of the material during solidification (which is inversely calculated from the expansion characteristics, and the expansion coefficient is negative when cooling, i.e. shrinkage) is input, and the volume shrinkage difference is calculated by simulating the solidification process, which is the solidification shrinkage compensation amount.

[0088] S420, determining the amplitude adjustment range of the pulse pressure parameters based on the flow resistance coefficient.

[0089] Exemplarily, according to the flow resistance coefficient, if the coefficient is large (the molten metal is difficult to flow), the minimum pressure value of the material molten metal overcoming the corresponding resistance is determined, which is the minimum amplitude; combined with the structure pressure limit of the thin-walled intersection area of the valve body (to avoid pressure cracking), the maximum amplitude is determined, and the amplitude adjustment range of the pulse pressure boosting parameter is between the two.

[0090] S430, determining a gradient change curve of the pressure maintaining strength parameter according to the solidification shrinkage compensation amount; wherein the gradient change curve is used to indicate the change trend of the pressure maintaining strength parameter in the thick-walled boss area of the valve rod.

[0091] It can be understood that the gradient change curve is the change trend line of the pressure maintaining strength at different positions in the thick-walled boss area, for example, the pressure difference between the center and the edge.

[0092] Exemplarily, it is determined that the shrinkage is the most serious at the center of the thick-walled boss area (i.e. the compensation amount is the largest), and the shrinkage is lighter at the edge (i.e. the compensation amount is small), and then according to the solidification shrinkage compensation amount calculation, the pressure maintaining strength values of the center, the middle and the edge are distributed in the way of high pressure maintaining strength corresponding to large compensation amount, and the position coordinates and the corresponding pressure maintaining strength values are corresponded to draw the gradient change curve.

[0093] S440, determining the liquid feeding data according to the amplitude adjustment range and the gradient change curve.

[0094] Exemplarily, the amplitude adjustment range (for example, 0.8-1.2MPa) is combined with the curve (for example, the center pressure maintaining 1.2MPa, the edge 0.8MPa), the pressure maintaining pressure of each area is determined according to the curve, the pulse pressure boosting starting time (when the thick-walled area starts to solidify) is determined according to the amplitude range, and then the feeding amount of each area is calculated according to the solidification shrinkage compensation amount, and the pressure, the time and the amount are integrated to form the liquid feeding data.

[0095] In this way, the characteristics of the flange flow channel intersection and the valve rod mounting boss and other composite structure transition areas can be targeted to develop appropriate liquid feeding schemes, so that these areas can be fully fed during the casting process to reduce the generation of defects; by accurately controlling the pulse pressure boosting parameters and the pressure maintaining strength parameters, the flow and feeding effect of the liquid metal can be optimized, and the casting quality and efficiency can be improved.

[0096] In one possible implementation, please refer to Figure 6 S400, determining the liquid feeding data of the composite structure transition area based on the expansion characteristics of the valve body, comprising:

[0097] S401, determining the change curve of the expansion coefficient in the expansion characteristics of the material of the valve body at different temperatures; wherein the change curve of the expansion coefficient is used to indicate the volume expansion trend of the material of the valve body in the heating process.

[0098] It can be understood that the expansion coefficient refers to the relative change in the volume of the material caused by a unit temperature change, which reflects the volume expansion trend of the material during heating.

[0099] Exemplarily, by obtaining the volume expansion data of the valve body material at different temperatures, the data is plotted into a change curve of the expansion coefficient. Through the change curve, the expansion characteristics of the valve body material at different temperature stages can be determined, including the change of the expansion rate, the accumulation of the expansion amount, etc.

[0100] S402, determining a volume expansion difference value of the material of the valve body based on the change curve of the expansion coefficient; wherein the volume expansion difference value is used to indicate the volume change amplitude caused by temperature change.

[0101] Exemplarily, the pouring temperature of the molten metal and the room temperature after solidification are determined, the expansion coefficients of the two temperatures are determined from the curve, and the volumes at the two temperatures are calculated respectively by using the formula volume = initial volume x (1+expansion coefficient x temperature difference), and the volume expansion difference value is obtained by subtracting the two.

[0102] S403, generating liquid feeding data according to the volume expansion difference value.

[0103] Exemplarily, for the complex structure transition areas such as the intersection of flange runner and the mounting boss of valve stem, the liquid metal feeding amount corresponding to the size of the volume expansion difference value is obtained according to the size of the volume expansion difference value, so that these areas can be fully fed during solidification. Specifically, the corresponding feeding parameters such as feeding time, feeding pressure and feeding amount can be set, and these parameters are integrated to form the liquid feeding data.

[0104] In this way, the volume change of the valve body material during casting can be more accurately reflected, so that a more reasonable liquid feeding scheme can be developed. After determining the volume expansion difference value, the influence of the expansion difference of different areas on the liquid metal feeding demand can be further analyzed. For example, for the areas with larger expansion difference, larger feeding amount and higher feeding pressure may be needed to ensure that the liquid metal can fully fill the gap caused by solidification shrinkage. At the same time, according to the change curve of the expansion coefficient, the thermal stress and deformation of the valve body during casting can also be predicted.

[0105] S500, by the valve body pressure sealing performance and the metal liquid viscosity temperature characteristics, and according to the casting process, the phase transition pressure data is constructed; wherein the phase transition pressure data is used to indicate the dynamic pressure threshold of the valve body before solidification, and the casting process includes the pressure increasing process, the crystallization process and the pressure relief process.

[0106] It can be understood that the valve body pressure sealing performance refers to the ability of the valve body to prevent medium leakage when subjected to pressure; the metal liquid viscosity-temperature characteristic refers to the law of change of the viscosity of the metal liquid with temperature (the viscosity generally increases with the decrease of temperature);

[0107] Exemplarily, through the valve body pressure sealing performance test data (such as the leakage pressure of the pressure test) and the viscosity data of the metal liquid at different temperatures, the data is processed in stages according to the casting process, that is, the temperature of the viscosity mutation of the metal liquid is recorded in the pressure increasing stage, the relationship between the pressure and the metal liquid advancing speed is recorded in the crystallization stage, and the critical value of the sealing performance is combined in the pressure releasing stage, that is, the dynamic pressure threshold table changing with temperature or time is generated, that is, the phase change pressure data is obtained.

[0108] In a possible implementation, please refer to Figure 7 , S500, the phase change pressure data is constructed by the valve body pressure sealing performance and the metal liquid viscosity-temperature characteristic and according to the casting process, including:

[0109] S510, the critical value of the pressure sealing performance in the design index of the valve body is determined; wherein the critical value is used to indicate the requirement of the valve body to maintain the sealing state when subjected to a specific pressure.

[0110] Exemplarily, the critical value of the pressure sealing performance can be determined by referring to the valve body design drawing or product standard to obtain the rated sealing pressure, then the valve body sealing surface is fitted, the pressure is slowly increased in the valve body, 0.1 MPa is increased every 5 minutes, and it is observed whether there is leakage on the sealing surface (soap water can be used to detect bubbles), when the bubbles appear for the first time, the pressure value is the critical value of the pressure sealing performance.

[0111] S520, the critical transition point of the metal liquid viscosity-temperature characteristic is determined in the pressure increasing process; wherein the critical transition point is used to represent the temperature point at which the viscosity of the metal liquid changes significantly with temperature in the solidification process.

[0112] Exemplarily, the rotational viscometer measures the viscosity value every 20℃ from the metal liquid pouring temperature (for example, 1450℃) in the pressure increasing environment (for example, 0.5-1 MPa simulating the pressure increasing pressure of casting), records the corresponding data of temperature and viscosity, and then determines the temperature point of the viscosity mutation through the corresponding data, and the temperature point of the viscosity mutation is determined as the critical transition point.

[0113] In a possible implementation, please refer to Figure 2 , S520, the critical transition point of the metal liquid viscosity-temperature characteristic is determined in the pressure increasing process, including:

[0114] S521, the derivative curve of the viscosity change rate changing with temperature is constructed in the pressure increasing process.

[0115] Exemplarily, by the original data of different temperatures and viscosities, the viscosity difference (the viscosity at the next temperature minus the viscosity at the previous temperature) of each two adjacent temperature points is calculated, and then divided by the temperature difference, to obtain the viscosity change rate of each temperature interval. The temperature and the corresponding viscosity change rate are corresponded one by one to obtain a smooth curve, that is, the derivative curve of the viscosity change rate with respect to the temperature.

[0116] S522, identifying the inflection point position of the slope mutation in the derivative curve.

[0117] Exemplarily, the derivative curve obtained in step S521 is subjected to piecewise fitting, the slope of each segment of the curve is calculated, and the slope values of adjacent two segments are compared. If the slope difference at a position exceeds a set threshold value (for example, the slope suddenly increases from 5 mPa·s / ℃² to 20 mPa·s / ℃²), the position is the inflection point of the slope mutation in the derivative curve.

[0118] S523, determining the temperature value corresponding to the inflection point position as the critical transition point.

[0119] Exemplarily, the temperature value corresponding to the inflection point position can be determined as the critical transition point, which can be that, according to the determined inflection point position, a straight line perpendicular to the horizontal axis (temperature axis) is drawn from the inflection point, and the intersection point of the straight line and the horizontal axis corresponds to the temperature value of the critical transition point of the viscosity-temperature characteristic of the metal liquid.

[0120] S530, determining the pressure change data in the phase change process of the metal liquid during the crystallization process; wherein the pressure change data is used to reflect the relationship between the propelling speed before solidification of the valve body and the pressure.

[0121] It can be understood that the crystallization process refers to the process of cooling the metal liquid from liquid state to solid state, and the atomic arrangement changes from disorder to order. The pressure change data in the phase change process of the metal liquid records the corresponding relationship between the pressure in the mold and the propelling speed (the speed of filling the mold cavity) of the metal liquid during the crystallization stage.

[0122] Exemplarily, in the crystallization stage of casting, the pressure sensor is used to collect the pressure in the mold in real time (1 record per 10 seconds), and the propelling speed of the metal liquid is calculated according to the process of filling the mold cavity by image analysis (for example, 5 mm per second), so as to correspond the pressure value and the propelling speed at the same time point one by one to obtain the corresponding result. The corresponding result is arranged to obtain the corresponding relationship between the pressure and the propelling speed, that is, the pressure change data.

[0123] S540, determining the phase transition pressure data according to the pressure change data, the critical value and the critical transition point during the pressure relief process.

[0124] It can be understood that the pressure relief process refers to the process of gradually reducing the pressure in the mold to atmospheric pressure after the crystallization stage is completed.

[0125] Exemplarily, the pressure sealing critical value is taken as the upper limit of the phase change pressure; then, the critical transition point is taken as the boundary, when the temperature is higher than 1250℃, the pressure value corresponding to the propelling rate of ≥3mm / s is taken as the pressure threshold value of the temperature segment, when the temperature is lower than 1250℃, the pressure value corresponding to the propelling rate of ≥2mm / s is taken as the threshold value, then the pressure threshold values of different temperature segments are arranged in time sequence to obtain the phase change pressure data.

[0126] In this way, the pressure sealing performance of the valve body, the viscosity-temperature characteristics of the molten metal, and the pressure rising, crystallization and pressure relief stages in the casting process can be comprehensively considered to formulate more accurate phase change pressure data. When formulating the phase change pressure data, not only the design indicators of the valve body and the physical characteristics of the molten metal are considered, but also the actual situation of the casting process is combined, so that the obtained data can more accurately reflect the pressure change of the valve body in the casting process. By setting the pressure threshold value in sections, the pressure value corresponding to the propelling rate of the molten metal in different temperature segments can be determined, thereby improving the casting quality.

[0127] S600, determining optimization data based on the spatial mapping relationship, the liquid feeding data and the phase change pressure data; wherein the optimization data is used to indicate the optimized low-pressure casting pressure curve of the valve body.

[0128] Exemplarily, the spatial mapping relationship is taken as a constraint (for example, the thick-walled boss area corresponds to higher pressure retention), the liquid feeding data is adjusted, and then the time distribution of the pulse pressure increasing parameter and the pressure retention intensity parameter is adjusted according to the phase change pressure data. The adjusted pressure parameters are arranged in the casting time sequence to obtain the optimization data.

[0129] In summary, the control of the local area in the casting process can be improved, and the defects caused by the fixed pressure curve in the traditional low-pressure casting method can be avoided, thereby effectively avoiding the spatter and gas entrapment problem caused by the too high pressure in the thin-walled area and the shrinkage problem caused by the insufficient pressure in the thick-walled area, and improving the casting quality and use reliability of the valve body.

[0130] In a possible implementation, please refer to Figure 8 S600, determining optimization data based on the spatial mapping relationship, the liquid feeding data and the phase change pressure data, comprising:

[0131] S610, taking the spatial mapping relationship as a constraint condition for spatial distribution of the liquid feeding data.

[0132] It can be understood that the constraint condition for spatial distribution refers to the spatial rules (for example, the feeding amount in the thick-walled area is greater than that in the thin-walled area, and the feeding pressure near the runner area is greater than that away from the runner area) that need to be followed when the feeding amount and feeding pressure are allocated to different areas of the valve body.

[0133] Exemplarily, according to the liquid feeding data and the mapping relationship, 60% of the feeding amount is allocated to the thick-wall boss area and 40% of the feeding amount is allocated to the thin-wall area, and the feeding pressure of the thick-wall area is set to 1.2 MPa and the feeding pressure of the thin-wall area is set to 0.8 MPa, so as to be able to allocate the feeding amount in accordance with the spatial structure requirement.

[0134] In S620, the time sequence distribution of the pulse pressurization parameter and the pressure holding intensity parameter is adjusted based on the dynamic pressure threshold in the phase transition pressure data to obtain allocation data; wherein the allocation data is used to indicate the pressure allocation strategy.

[0135] It can be understood that the time sequence distribution refers to the arrangement order of the pulse pressurization parameter (such as the pressure amplitude and the interval time) and the pressure holding intensity parameter (such as the pressure holding pressure and the pressure holding time) on the casting time axis.

[0136] Exemplarily, when the temperature of the metal liquid decreases to the critical transition point, the viscosity increases significantly, at this time, the pulse pressurization needs to be started to avoid poor filling caused by the increase of the viscosity; in the crystallization phase of the casting, the pressure holding intensity is dynamically adjusted according to the corresponding relationship between the pressure change data and the metal liquid advancing rate, so that the metal liquid can smoothly advance and fully fill the cavity; in the pressure relief phase of the casting, the pressure in the mold is gradually reduced in combination with the pressure-bearing sealing critical value, so that the valve body does not produce defects due to the sudden change of the pressure in the solidification process, and then the distribution of the pulse pressurization parameter and the pressure holding intensity parameter on the time axis can be optimized according to the adjustment to obtain more reasonable allocation data.

[0137] In S630, the allocation data and the spatial allocation result are integrated to obtain optimization data.

[0138] Exemplarily, the pulse pressurization parameter and the pressure holding intensity parameter in the allocation data are one-to-one corresponding to the feeding amount and the feeding pressure in the spatial allocation result, a curve is drawn according to the allocation data, and then the pressure value and the change rate of the key time point on the curve are extracted, that is, the integration is the optimization data.

[0139] In this way, the optimization data can not only meet the spatial structure characteristics of the valve body, but also adapt to the dynamic pressure change in the casting process, the allocation of the liquid feeding data can be constrained through the spatial mapping relationship, the feeding requirements of different areas can be met, and the conditions of excessive feeding or insufficient feeding can be avoided.

[0140] It should be understood that the size of the serial number of each step in the above embodiment does not mean the execution order, the execution order of each process should be determined according to its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0141] Corresponding to the ball valve body low-pressure casting pressure curve self-adaptive optimization method described in the above embodiments, the ball valve body low-pressure casting pressure curve self-adaptive optimization system is also provided, and each unit of the system can realize each step of the ball valve body low-pressure casting pressure curve self-adaptive optimization method. Figure 9 The structural block diagram of the ball valve body low-pressure casting pressure curve self-adaptive optimization system provided by the embodiments of the application is shown, and only the parts related to the embodiments of the application are shown for ease of illustration.

[0142] Referring to Figure 9 The ball valve body low-pressure casting pressure curve self-adaptive optimization system comprises:

[0143] The acquisition unit is configured to acquire the shrinkage data corresponding to the main load-bearing structure region of the valve body in the first low-pressure casting stage and the thermal gradient distribution characteristics in the second low-pressure casting stage; wherein the shrinkage data comprises a pressure spectrum and a shrinkage defect spectrum, and the thermal gradient distribution characteristics are used to reflect the distribution of the temperature change rate of the valve body during the solidification process;

[0144] The first determination unit is configured to determine the composite structure data associated with the main load-bearing structure region of the valve body; wherein the composite structure data is used to reflect the morphology of the composite structure transition region, and the composite structure transition region comprises a flange runner intersection and a valve rod mounting boss;

[0145] The second determination unit is configured to determine the spatial mapping relationship according to the shrinkage data, the thermal gradient distribution characteristics and the composite structure data; wherein the spatial mapping relationship is used to indicate the corresponding relationship between the defect concentration area and the composite structure transition region;

[0146] The third determination unit is configured to determine the liquid feeding data of the composite structure transition region based on the expansion characteristics of the valve body; wherein the liquid feeding data comprises the pulse pressure increasing parameters of the thin-walled intersection area of the flange runner intersection and the pressure maintaining strength parameters of the thick-walled boss area of the valve rod mounting boss;

[0147] The construction unit is configured to construct the phase change pressure data according to the valve body pressure sealing performance and the metal liquid viscosity-temperature characteristics and the casting process; wherein the phase change pressure data is used to indicate the dynamic pressure threshold before the solidification of the valve body, and the casting process comprises a pressure increasing process, a crystallization process and a pressure releasing process;

[0148] The result unit is configured to determine the optimization data based on the spatial mapping relationship, the liquid feeding data and the phase change pressure data; wherein the optimization data is used to indicate the optimized valve body low-pressure casting pressure curve.

[0149] It should be noted that the information interaction and execution process between the above systems / units 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, and they will not be repeated here.

[0150] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the system can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0151] This application also provides an adaptive optimization device for the low-pressure casting pressure curve of a ball valve body. Figure 10 This is a schematic diagram of the structure of an adaptive optimization device for the low-pressure casting pressure curve of a ball valve body provided in an embodiment of this application. Figure 10 As shown, the adaptive optimization device 6 for the low-pressure casting pressure curve of the ball valve body in this embodiment includes: at least one processor 60 ( Figure 10 Only one is shown in the image), at least one memory 61 ( Figure 10 (Only one is shown in the image) and a computer program 62 stored in the at least one memory 61 and executable on the at least one processor 60. When the processor 60 executes the computer program 62, it causes the ball valve body low-pressure casting pressure curve adaptive optimization device 6 to implement the steps in any of the above embodiments of the ball valve body low-pressure casting pressure curve adaptive optimization method, or causes the ball valve body low-pressure casting pressure curve adaptive optimization device 6 to implement the functions of each module / unit in the above embodiments of the system.

[0152] For example, the computer program 62 may be divided into one or more modules / units, which are stored in the memory 61 and executed by the processor 60 to complete this application. The one or more modules / units may be a series of computer program instruction segments capable of performing specific functions, which describe the execution process of the computer program 62 in the ball valve body low-pressure casting pressure curve adaptive optimization device 6.

[0153] The ball valve body low-pressure casting pressure curve self-adaptive optimization device 6 can be a desktop computer, a notebook computer, or the like. The ball valve body low-pressure casting pressure curve self-adaptive optimization device can include, but is not limited to, a processor 60, a memory 61. Those skilled in the art can understand that, Figure 10 The ball valve body low-pressure casting pressure curve self-adaptive optimization device 6 is only an example and does not constitute a limitation on the ball valve body low-pressure casting pressure curve self-adaptive optimization device 6, which can include more or fewer components than those shown, or combine certain components, or different components, for example, can also include input / output devices, network access devices, buses, etc.

[0154] The processor 60 can be a central processing unit (CPU), and can also be other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or can also be any conventional processor.

[0155] The memory 61 can be an internal storage unit of the ball valve body low-pressure casting pressure curve self-adaptive optimization device 6 in some embodiments, such as a hard disk or a memory of the ball valve body low-pressure casting pressure curve self-adaptive optimization device 6. The memory 61 can also be an external storage device of the ball valve body low-pressure casting pressure curve self-adaptive optimization device 6 in other embodiments, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. Further, the memory 61 can include both the internal storage unit and the external storage device of the ball valve body low-pressure casting pressure curve self-adaptive optimization device 6. The memory 61 is used to store an operating system, application programs, a boot loader, data, and other programs, such as program codes of the computer program, etc. The memory 61 can also be used to temporarily store data that has been output or will be output.

[0156] The embodiment of the present application further provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the steps in any of the above method embodiments.

[0157] The embodiment of the present application provides a computer program product, when the computer program product is run on the ball valve body low-pressure casting pressure curve adaptive optimization device, the ball valve body low-pressure casting pressure curve adaptive optimization device implements the steps in any of the above method embodiments.

[0158] The integrated unit, if realized in the form of a software functional unit and sold or used as an independent product, can be stored in a computer readable storage medium. Based on such understanding, the present application implements all or part of the processes in the above embodiment methods, which can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a computer readable storage medium, and the computer program, when executed by a processor, can implement the steps of the above method embodiments. The computer program includes computer program code, which can be in the form of source code, object code, executable files or some intermediate forms. The computer readable medium at least includes any entity or device capable of carrying the computer program code to the ball valve body low-pressure casting pressure curve adaptive optimization device, a recording medium, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunications signal and a software distribution medium. For example, a U disk, a mobile hard disk, a magnetic disk or an optical disk.

[0159] In the above embodiments, the description of each embodiment has its own focus, and the parts not described or recorded in detail in a certain embodiment can be referred to the relevant description of other embodiments.

[0160] Those skilled in the art can realize that the units and algorithm steps of the examples described in combination with the embodiments disclosed herein can be realized by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are realized in hardware or software depends on the specific application and design constraints of the technical solution. The skilled person can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0161] In the embodiments provided by the present application, it should be understood that the disclosed ball valve body low-pressure casting pressure curve adaptive optimization system, device and method can be implemented in other manners. For example, the ball valve body low-pressure casting pressure curve adaptive optimization system and device embodiments described above are merely illustrative. For example, the division of the modules or units is merely a logical function division. There can be another division manner in actual implementation. For example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the display or discussion of the coupling or direct coupling or communication connection between the modules can be indirect coupling or communication connection through some interfaces, devices or units. The coupling or communication connection can be electrical, mechanical or in other forms.

[0162] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, i.e., can be located in one place or can be distributed on a plurality of network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiments.

[0163] The above-described embodiments are merely used to illustrate the technical solutions of the present application, but not limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A ball valve body low pressure casting pressure curve self-adaptive optimization method, characterized in that, The method comprises: obtaining the shrinkage data corresponding to the main load-bearing structure region of the valve body in the first low-pressure casting stage and the thermal gradient distribution characteristics in the second low-pressure casting stage; wherein the shrinkage data comprises a pressure spectrum and a solidification defect spectrum, and the thermal gradient distribution characteristics are used to reflect the distribution of the temperature change rate of the valve body during solidification; determining the composite structure data associated with the main load-bearing structure region of the valve body; wherein the composite structure data is used to reflect the morphology of the composite structure transition region, and the composite structure transition region includes the flange runner intersection and the valve rod mounting boss; determining the spatial mapping relationship according to the shrinkage data, the thermal gradient distribution characteristics and the composite structure data; wherein the spatial mapping relationship is used to indicate the correspondence between the defect concentration area and the composite structure transition region; determining the liquid feeding data of the composite structure transition region based on the expansion characteristics of the valve body; wherein the liquid feeding data comprises the pulse pressure increasing parameters of the thin-walled intersection area of the flange runner intersection and the pressure holding strength parameters of the thick-walled boss area of the valve rod mounting boss; constructing the phase change pressure data according to the valve body pressure sealing performance and the metal liquid viscosity-temperature characteristics and the casting process; wherein the phase change pressure data is used to indicate the dynamic pressure threshold before the valve body solidifies, and the casting process comprises a pressure increasing process, a crystallization process and a pressure relief process; determining the optimization data based on the spatial mapping relationship, the liquid feeding data and the phase change pressure data; wherein the optimization data is used to indicate the optimized low-pressure casting pressure curve of the valve body; wherein the determination of the composite structure data associated with the main load-bearing structure region of the valve body comprises: determining the geometric boundary conditions of the flange runner intersection and the valve rod mounting boss in the structure model of the valve body; determining the state of the main load-bearing structure region of the valve body based on the geometric boundary conditions to obtain the composite structure data; the determination of the spatial mapping relationship according to the shrinkage data, the thermal gradient distribution characteristics and the composite structure data comprises: determining the pressure abnormal data according to the pressure spectrum and the solidification defect spectrum included in the shrinkage data, and determining the temperature mutation area according to the thermal gradient distribution characteristics; wherein the pressure abnormal data is used to indicate the pressure abnormal area; spatially superimposing the pressure abnormal area and the temperature mutation area to obtain the defect area; wherein the defect area is used to indicate the potential defect concentration area of the valve body during the casting process; analyzing the defect area and the morphology reflected by the composite structure data to obtain the spatial mapping relationship.

2. The ball valve body low pressure casting pressure curve self-adaptive optimization method of claim 1, wherein, the determination of the liquid feeding data of the composite structure transition region based on the expansion characteristics of the valve body comprises: determining the metal liquid flow resistance coefficient of the thin-walled intersection area of the flange runner intersection and the solidification shrinkage compensation amount of the thick-walled boss area of the valve rod mounting boss according to the expansion characteristics; determining the amplitude adjustment range of the pulse pressure increasing parameters based on the flow resistance coefficient; determining a gradient variation curve of the holding strength parameter according to the solidification shrinkage compensation amount; wherein the gradient variation curve is used to indicate a variation trend of the holding strength parameter in the thick-wall boss area of the valve stem; determining the liquid feeding data according to the amplitude adjustment range and the gradient variation curve.

3. The ball valve body low pressure casting pressure curve self-adaptive optimization method of claim 2, wherein, determining the liquid feeding data of the transition area of the composite structure based on the expansion characteristics of the valve body, comprising: determining a variation curve of the expansion coefficient in the expansion characteristics of the material of the valve body at different temperatures; wherein the variation curve of the expansion coefficient is used to indicate a volume expansion trend of the material of the valve body in the heating process; determining a volume expansion difference value of the material of the valve body based on the variation curve of the expansion coefficient; wherein the volume expansion difference value is used to indicate a volume change amplitude caused by temperature change; generating the liquid feeding data according to the volume expansion difference value.

4. The ball valve body low pressure casting pressure curve self-adaptive optimization method of claim 3, wherein, determining the phase transition pressure data according to the pressure containment sealing performance of the valve body and the viscosity-temperature characteristics of the molten metal, comprising: determining a critical value of the pressure containment sealing performance in the design index of the valve body; wherein the critical value is used to indicate a requirement for the valve body to maintain a sealed state when bearing a specific pressure; determining a critical transition point of the viscosity-temperature characteristics of the molten metal in the pressure increasing process; wherein the critical transition point is used to represent a temperature point at which the viscosity of the molten metal significantly changes with temperature in the solidification process; determining pressure change data in the phase transition process of the molten metal in the crystallization process; wherein the pressure change data is used to reflect a relationship between the pushing rate of the valve body before solidification and pressure; determining the phase transition pressure data according to the pressure change data, the critical value and the critical transition point in the pressure releasing process.

5. The ball valve body low pressure casting pressure curve self-adaptive optimization method of claim 2, wherein, determining the optimization data based on the spatial mapping relationship, the liquid feeding data and the phase transition pressure data, comprising: taking the spatial mapping relationship as a constraint condition for spatial distribution of the liquid feeding data; adjusting a time sequence distribution of the pulse pressure increasing parameter and the holding strength parameter based on a dynamic pressure threshold in the phase transition pressure data to obtain distribution data; wherein the distribution data is used to indicate a pressure distribution strategy; determining the optimization data according to the distribution data.

6. The ball valve body low pressure casting pressure curve self-adaptive optimization method of claim 4, wherein, determining the critical transition point of the viscosity-temperature characteristics of the molten metal in the pressure increasing process, comprising: constructing a derivative curve of the viscosity change rate with respect to temperature change in the pressure increasing process; identifying an inflection point position of the derivative curve where the slope suddenly changes; determining a temperature value corresponding to the inflection point position as the critical transition point.

7. The ball valve body low pressure casting pressure curve self-adaptive optimization method according to any one of claims 1 to 6, characterized in that, acquiring solidification defect data corresponding to a main load-bearing structure area of the valve body in a first low-pressure casting stage and thermal gradient distribution characteristics in a second low-pressure casting stage, comprising: analyzing a solidification shrinkage defect distribution pattern of the main load-bearing structure area of the valve body in the casting simulation result; generating the pressure spectrum and the solidification defect spectrum according to the solidification shrinkage defect distribution pattern; acquiring a solidification temperature field, and calculating a temperature change rate spatial distribution according to the solidification temperature field to determine the thermal gradient distribution characteristics.

8. A device for adaptive optimization of low pressure casting pressure curves for ball valve bodies, comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that, The processor implements the method as claimed in any one of claims 1 to 7 when executing the computer program.

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