Impeller-type shell drying time determination method, electronic device, and medium

Abstract

The application discloses a kind of impeller shell drying time determination method, electronic equipment and medium, it is related to foundry technology field in manufacturing industry, method includes: obtaining the mapping relationship of water content and reference impeller shell shell mass;Determine the target water content corresponding to target shell mass in mapping relationship;According to the initial water content of target impeller shell at initial time, target water content and drying model corresponding to basic drying environment, determine the basic drying time of target impeller shell;According to the actual water content of target impeller shell at basic drying time, optimize drying model until the actual water content of target impeller shell is consistent with target water content, obtain the drying model corresponding to current drying environment;Utilize the drying model obtained to determine the target drying time of similar target impeller shell under current drying environment.The application has the advantages of adapting to multiple drying environments, intelligently determining drying time, improving shell quality and casting quality.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of foundry technology in manufacturing industry, and in particular to a method for determining drying time of a vane shell, an electronic device and a medium. BACKGROUND

[0002] A shell is a ceramic shell with precise internal cavity used to form the shape of a casting in the precision casting process. The shell-making process includes multiple layers of coating and drying for the replica of the casting "wax film", heating the dried coating to melt the "wax film", and finally obtaining a multi-layer ceramic shell, which is the shell. The drying time determines the quality of the shell, and the quality of the shell directly determines the quality of the casting.

[0003] In the shell-making process of vane products, the method for determining the drying time of each layer (i.e. shell film) of the vane shell includes two types: relying on traditional experience and relying on high-precision control system. In the traditional experience, a fixed drying time or manual touch is adopted to confirm the drying degree of each layer of shell film; the high-precision control system sets the shell-making workshop as a constant temperature and humidity system to control the drying environment, providing a stable drying environment and drying time for the shell film drying.

[0004] According to actual measurement verification, the above methods all have the problem of poor shell quality, which further reduces the quality of the casting. SUMMARY

[0005] The present application aims to solve one of the problems in the related art to some extent. To this end, the present application provides a method for determining the drying time of a vane shell, an electronic device for executing the drying time determination method and a computer readable medium, which has the advantages of adapting to various drying environments, intelligently determining the drying time, improving the consistency of the shell quality and the quality of the casting.

[0006] In order to achieve the above-mentioned purpose, as a first aspect of the present application, a method for determining the drying time of a vane shell is provided, wherein the drying time determination method comprises:

[0007] obtaining a mapping relationship between water content and shell quality of a reference vane shell;

[0008] determining a target water content corresponding to a target shell quality in the mapping relationship;

[0009] determining a basic drying time of a target vane shell according to an initial water content of the target vane shell at an initial time, the target water content and a drying model corresponding to a basic drying environment;

[0010] optimizing the drying model according to the actual water content of the target vane shell at the basic drying time until the actual water content of the target vane shell is consistent with the target water content, to obtain a drying model corresponding to a current drying environment;

[0011] Determine the target drying time of the same type of target impeller shell under the current drying environment by using the obtained drying model.

[0012] Optionally, the drying model comprises drying parameters; and the drying model is optimized according to the actual moisture content of the target impeller shell at the basic drying time until the actual moisture content of the target impeller shell is consistent with the target moisture content, so as to obtain a drying model corresponding to the current drying environment, comprising:

[0013] Determine a target moisture content range according to the preset moisture content window and the target moisture content;

[0014] In a case where it is detected that the actual moisture content of the target impeller shell at the basic drying time is in the target moisture content range, the drying model is taken as the drying model corresponding to the current drying environment;

[0015] In a case where it is detected that the actual moisture content of the target impeller shell at the basic drying time is not in the target moisture content range, the drying parameters of the drying model are fitted by using the initial moisture content and the target moisture content, and the fitted drying parameters are taken as the drying parameters of the drying model corresponding to the current drying environment.

[0016] Optionally, the drying parameters of the drying model are fitted by using the initial moisture content and the target moisture content, and the fitted drying parameters are taken as the drying parameters of the drying model corresponding to the current drying environment, comprising:

[0017] Determine a moisture content sampling interval according to the initial moisture content and the target moisture content range;

[0018] Obtain a plurality of candidate actual moisture contents at intervals in the moisture content sampling interval;

[0019] Substitute the candidate actual moisture contents corresponding to a plurality of interval times into the drying model, and fit the drying parameters of the drying model by using a linear regression algorithm.

[0020] Optionally, the drying model satisfies the following formula (1):

[0021] (1)

[0022] wherein, is an initial moisture content of the target impeller shell at an initial time;

[0023] t is time;

[0024] M(t) is a moisture content of the target impeller shell at time t;

[0025] K is a drying constant of the drying model, in a basic drying environment, K is a drying constant of the drying model corresponding to the basic drying environment; in a current drying environment, K is a drying constant of the drying model corresponding to the current drying environment; wherein at least one of the temperature, humidity and wind speed in the current drying environment is different from the basic drying environment.

[0026] Optionally, the target impeller type shell includes a plurality of layer films, and the drying time determination method further includes:

[0027] In a case where the target drying time of the target impeller type shell of the same type is determined, the determined target drying time is adjusted according to the position of the layer film in the impeller type shell;

[0028] In a case where the layer film is a surface layer of the target impeller type shell, the determined target drying time is reduced according to a first proportion parameter; wherein the surface layer is the innermost layer film of the target impeller type shell;

[0029] In a case where the layer film is a sealing layer of the target impeller type shell, the determined target drying time is reduced according to a second proportion parameter; wherein the sealing layer is the outermost layer film of the target impeller type shell; and the second proportion parameter is greater than the first proportion parameter;

[0030] In a case where the layer film is any layer between the surface layer and the sealing layer of the target impeller type shell, the determined target drying time is maintained.

[0031] Optionally, the shell quality includes defect probabilities corresponding to each defect type of the shell;

[0032] The target moisture content corresponding to the target shell quality in the mapping relationship includes:

[0033] Each defect type of the shell corresponding to the moisture content in the mapping relationship is assigned a weight;

[0034] A weighted sum corresponding to the moisture content is determined according to the defect probability of each defect type and the assigned weight, and the weighted sum is taken as the shell quality, so as to obtain the shell quality corresponding to each moisture content one by one;

[0035] The lowest weighted sum is taken as the target shell quality, and the moisture content corresponding to the target shell quality is taken as the target moisture content.

[0036] Optionally, the assigning of the weight to each defect type of the shell corresponding to the moisture content in the mapping relationship includes:

[0037] A probability average value is determined according to the defect probability of each defect type in the mapping relationship;

[0038] determining a probability standard deviation according to the defect probability of each moisture content in the mapping relationship;

[0039] dividing the probability standard deviation by the probability average value to obtain a moisture content sensitivity of the defect type;

[0040] assigning a weight to the defect type according to the moisture content sensitivity; wherein the higher the moisture content sensitivity, the higher the weight assigned to the corresponding defect type.

[0041] Optionally, the moisture content satisfies the following formula (2):

[0042] (2)

[0043] wherein, is the moisture content; is the weight of the mold shell before drying, is the weight of the mold shell after drying.

[0044] As a second aspect of the present application, an electronic device is provided, comprising:

[0045] one or more processors;

[0046] a memory having one or more computer programs stored thereon, wherein when the one or more computer programs are executed by the one or more processors, the one or more processors implement the drying time determination method according to the first aspect of the present application.

[0047] In addition, as a third aspect of the present application, a computer readable medium having a computer program stored thereon is also provided, wherein when the computer program is executed by a processor, the drying time determination method according to the first aspect of the present application is implemented.

[0048] The drying time determination method for the impeller mold shell provided by the present application provides accurate and sufficient data support for the subsequent drying time determination method through the mapping relationship established based on a large amount of mold shell quality (such as embrittlement and cracking) data of reference impeller mold shells at different moisture contents. Then, the target moisture content is determined in reverse according to the expected target mold shell quality in the mapping relationship, and the basic drying time is determined in combination with the initial moisture content of the target impeller mold shell of the same category as the reference impeller mold shell, the target moisture content, and the preset drying model. Considering that the preset drying model is a factor for establishing the basic drying environment, therefore, in the case that the current drying environment is different from the basic drying environment, the drying model is optimized through the actual moisture content feedback of the target impeller mold shell at the basic drying time until the actual moisture content is consistent with the target moisture content, and finally the drying model matched with the current drying environment is obtained. Finally, the target drying time of the batch of impeller mold shells of the same category in the current drying environment is determined according to the optimized drying model.

[0049] Compared with the traditional method of determining the drying time depending on experience, the method does not need to rely on manual judgment, can actively adapt to different drying environments, intelligently adjusts the drying time according to different drying environments, fundamentally avoids the quality problems of the shell such as brittleness and cracks caused by the subjectivity of experience judgment, greatly improves the stability of the shell quality, and further ensures the consistency of the casting quality. In addition, compared with the method of controlling the drying environment of the shell making workshop based on a high-precision control system, the method does not need to additionally invest in the cost of workshop environment regulation and control equipment, reduces the cost while reducing the harsh requirements for the environmental parameter variables in the drying environment (that is, improves the adaptability to different drying environments), further simplifies the operation process of the shell making process, and in addition, although the high-precision control workshop can provide a relatively stable drying environment, the drying time still needs to rely on manual determination, and therefore the shell quality problem still exists. The method can adapt to different drying environments, actively adjusts the determined drying time for different drying environments, effectively solves the problem of uneven drying caused by unreasonable drying time setting, and improves the shell quality, the yield of castings and the stability of the quality.

[0050] The features and advantages of the present application will be described in detail in the following specific embodiments and drawings. The best mode or means of the present application will be fully described in conjunction with the drawings, but it is not a limitation on the technical solutions of the present application. In addition, the features, elements and components appearing in each of the following text and drawings are multiple, and different symbols or numbers are marked for convenience of representation, but all represent the same or similar structure or function parts. BRIEF DESCRIPTION OF DRAWINGS

[0051] The present application will be further described below in conjunction with the drawings:

[0052] Figure 1 A flowchart of a drying time determination method for a shell of an impeller provided by the present application;

[0053] Figure 2 A flowchart of an embodiment of the drying time determination method step S140 provided by the present application;

[0054] Figure 3 A flowchart of an embodiment of the drying time determination method step S143 provided by the present application;

[0055] Figure 4 A flowchart of an embodiment of the drying time determination method step S120 provided by the present application;

[0056] Figure 5 A flowchart of an embodiment of the drying time determination method step S121 provided by the present application;

[0057] Figure 6 A module diagram of an electronic device is provided.

[0058] Explanation of reference signs

[0059] Wherein, 101, a processor; 102, a memory; 103, an I / O interface; 104, a bus. DETAILED DESCRIPTION

[0060] Embodiments of the present application are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout. Based on the embodiments in the embodiments, it is intended to explain the present application, and cannot be understood as a limitation on the present application.

[0061] In this specification, "one embodiment" or "an example" or "an example" means that a specific feature, structure or characteristic described in connection with the embodiment itself can be included in at least one embodiment of the present disclosure. The appearance of the phrase "in one embodiment" at various places in the specification does not necessarily refer to the same embodiment.

[0062] For the method of relying on traditional experience to determine the drying time, it is obvious that the artificial judgment standard is inconsistent, which leads to different drying time conclusions for the same state of the impeller shell. After drying the shell according to the artificial determination of the drying time, it is difficult to avoid the quality problems such as cracks and burrs of the shell. For the method of relying on high-precision control system, although the shell making workshop can be set to a relatively stable environment, reducing the disturbance of temperature and humidity and other environmental factors on the drying process and the quality of the dried shell, the drying time directly affecting the quality of the shell still needs to be set by artificial, which cannot fundamentally solve the problem of inaccurate drying time set by human. The quality of the shell is still poor.

[0063] Therefore, in order to solve the problem of poor shell quality caused by artificial determination of drying time, as a first aspect of the present application, a drying time determination method for an impeller shell is provided, as shown in Figure 1 The drying time determination method comprises:

[0064] In step S110, a mapping relationship between water content and shell quality of a reference impeller shell is obtained;

[0065] In step S120, a target water content corresponding to a target shell quality in the mapping relationship is determined;

[0066] In step S130, a basic drying time of a target impeller shell is determined according to an initial water content of the target impeller shell at an initial time, the target water content and a drying model corresponding to a basic drying environment;

[0067] In step S140, the drying model is optimized according to the actual moisture content of the target impeller shell at the basis drying time until the actual moisture content of the target impeller shell is consistent with the target moisture content, obtaining a drying model corresponding to the current drying environment;

[0068] In step S150, the target drying time of the target impeller shell of the same type under the current drying environment is determined by using the obtained drying model.

[0069] The method for determining the drying time of the impeller shell provided by the application provides accurate and sufficient data support for the subsequent drying time determination method through the mapping relationship established based on the shell quality (such as brittleness and cracking) data of a large number of reference impeller shells at different moisture contents, and then the target moisture content is determined in reverse according to the expected target shell quality in the mapping relationship, and the basis drying time is determined in combination with the initial moisture content of the target impeller shell of the same type as the reference impeller shell, the target moisture content and the preset drying model. Considering that the preset drying model is a factor established under the basis drying environment, therefore, in the case that the current drying environment is different from the basis drying environment, the drying model is optimized through the actual moisture content of the target impeller shell at the basis drying time until the actual moisture content is consistent with the target moisture content, and finally the drying model matched with the current drying environment is obtained. Finally, the target drying time of the batch of impeller shells of the same type under the current drying environment is determined according to the optimized drying model.

[0070] Compared with the traditional method of determining the drying time depending on experience, this method does not need to rely on manual judgment, can actively adapt to different drying environments, intelligently adjusts the drying time according to different drying environments, fundamentally avoids the quality problems of shell brittleness, cracking and the like caused by the subjectivity of experience judgment, greatly improves the stability of shell quality, and further ensures the consistency of casting quality. In addition, compared with the method of controlling the drying environment of the shell making workshop based on a high-precision control system, no additional investment is required for the cost of workshop environment control equipment, which reduces the cost while reducing the harsh requirements for environmental parameter variables in the drying environment (i.e. improves the adaptability to different drying environments), further simplifies the operation process of the shell making process, and in addition, although the high-precision control workshop can provide a relatively stable drying environment, the drying time still needs to rely on manual determination, so there will still be problems of poor shell quality. The method can adapt to different drying environments, actively adjust the determined drying time for different drying environments, effectively solve the problem of uneven drying caused by unreasonable setting of the drying time, and improve the shell quality, the yield and the quality stability of the castings.

[0071] The mapping relationship is the core premise and data basis of the drying time determination method of the application, and directly determines the accuracy of the target moisture content and the determined final drying time. The construction process of the mapping relationship is described in detail as follows: during the shell making process of the impeller type shell, at the beginning of the drying process of each layer of coating slurry and sanding, the moisture content of the shell during the drying process is continuously monitored and calculated. For shells with different moisture contents, samples with the same variables in the same batch are extracted for casting, the surface quality of the castings after casting is detected, the types of defects on the surface of the castings and the probability of each type of defect occurring under the corresponding moisture content are counted, and finally the distribution table of different moisture contents and the quality of the reference impeller shell (the extracted shell) is obtained as shown in Table 1. Table 1 is the probability of defects in the reference impeller shell when the same impeller shell is cast at different moisture contents. In Table 1, the moisture content is measured in %, and the probability of all defect types is also measured in %. The data in the table is omitted to simplify presentation.

[0072] Table 1

[0073]

[0074] In Table 1 above, the defect types include burrs or sand sticking, inclusions or iron inclusion, shell swelling, cracking, cracking, layer falling, collapse or bulging, and air holes, which are several defect types that directly affect the quality of the castings. The probability of the above defect types occurring ranges from 1% to 3%, 0.5% to 2%, 20% to 25%, 15% to 30%, 0.1% to 1%, 20% to 30%, 0.1% to 0.3%, and 4% to 8% respectively. It should be noted that the above data takes into account the effect of water vapor on shell quality during the dewaxing process. In addition, it should be noted that the quality of the castings and the quality of the shell. In the casting process, the quality of the shell directly determines the quality of the castings, and since it is not possible to directly observe whether there are hidden problems such as uneven drying and cracking inside the shell, these problems are directly exposed on the surface of the castings. Therefore, the quality of the shell is evaluated by the indirect and reliable method of statistical casting quality defects and defect occurrence probability.

[0075] The drying time of the shell is closely related to the drying environment (temperature, humidity, wind speed, etc.) in which it is placed, and the current drying environment in which the actual shell building process is placed is often different from the basic drying environment in which the mapping relationship is constructed. If the drying model corresponding to the basic drying environment is directly used to determine the basic drying time, the drying time will not be able to adapt to the actual situation of the current drying environment, resulting in the shell being difficult to reach the preset target moisture content, and thus causing quality defects such as cracking, layering, burrs, etc. Therefore, in order to ensure the accuracy of the drying time and the quality of the shell, it is necessary to optimize the drying model for different drying environments to obtain a target drying time that adapts to the current environment. The drying parameters in the drying model reflect the variable information of temperature, humidity, wind speed, etc., and as an optional implementation of step S140, the drying model is optimized according to the actual moisture content of the target impeller shell at the basic drying time, until the actual moisture content of the target impeller shell is consistent with the target moisture content, as shown in Figure 2

[0076] In step S141, a target moisture content range is determined according to a preset moisture content window and the target moisture content.

[0077] In step S142, in the case where the actual moisture content of the target impeller shell at the basic drying time is detected to be in the target moisture content range, the drying model is taken as the drying model corresponding to the current drying environment.

[0078] In step S143, in the case where the actual moisture content of the target impeller shell at the basic drying time is detected to be not in the target moisture content range, the drying parameters of the drying model are fitted using the initial moisture content and the target moisture content, and the fitted drying parameters are taken as the drying parameters of the drying model corresponding to the current drying environment.

[0079] ​With the water content in Table 1 as 2% as the target water content, the preset water content window is set to ±0.2% according to experience, and the target water content range is 1.8%-2.2%, and the corresponding basic drying time is 16.8 hours. Based on the drying model corresponding to the basic drying environment, the actual water content after 16.8 hours of drying from the initial drying time after the target impeller shell coating process is calculated: if the actual water content is 1.9%, it is within the target water content range of 1.8%-2.2%, indicating that the current drying environment is less different from the basic drying environment, and the drying model corresponding to the basic drying environment can be used as the drying model corresponding to the previous drying environment; if the actual water content is 2.5%, which is outside the range of 1.8%-2.2%, it indicates that the target impeller shell is not dry enough, and compared with the basic drying environment, the current drying environment may be relatively humid, the temperature is relatively low, or the wind speed is relatively low, etc. At this time, a plurality of water content data from the initial drying time to the target water content is obtained, and the drying parameters of the drying model are fitted again to obtain a drying model adapted to the current drying environment. As an optional implementation of step S143, as shown in Figure 3 The drying parameters of the drying model are fitted using the initial water content and the target water content, and the fitted drying parameters are used as the drying parameters of the drying model corresponding to the current drying environment, including:

[0080] In step S143a, the water content sampling interval is determined according to the initial water content and the target water content range;

[0081] In step S143b, a plurality of candidate actual water contents are obtained at intervals within the water content sampling interval;

[0082] In step S143c, the candidate actual water contents corresponding to the plurality of interval times are substituted into the drying model, and the drying parameters of the drying model are fitted using a linear regression algorithm.

[0083] Considering that the drying degree of the target impeller shell at the basic drying time may be divided into two cases of over-drying (long drying time) or under-drying (short drying time), the above steps S143a-S143c aim to explain how to reasonably optimize the drying model for these two cases. The drying model satisfies the following formula (1):

[0084] (1)

[0085] Wherein, is the initial moisture content of the target impeller type shell measured at the initial drying time (i.e., initial time); t is time; M(t) is the moisture content of the target impeller type shell at time t; K is a drying constant of the drying model, under a basic drying environment, K is a drying constant of the drying model corresponding to the basic drying environment; under a current drying environment, K is a drying constant of the drying model corresponding to the current drying environment; it should be noted that the drying constant comprehensively reflects temperature, humidity and wind speed closely related to the drying environment; the higher the temperature, the greater the wind speed, and the lower the humidity, the greater the corresponding K value, and the faster the drying rate. The following embodiments will explain in detail how the present application compensates for the drying time under environmental changes based on the drying model.

[0086] Assuming that the basic drying environment is temperature 25℃, humidity 50%, and wind speed 0.5m / s, the initial moisture content M0=25% (measured initial moisture content after the pulp immersion and draining process) corresponds to the drying constant K=0.15h -1 , and the target moisture content M=2.0%, the basic drying time t calculated according to formula (1) is 16.8h.

[0087] For the case of insufficient drying: after 16.8h, the measured moisture content of the target impeller type shell is 2.5% (greater than the maximum value of the target moisture content range 1.8%-2.2%), and the current drying environment parameters are temperature 22℃, humidity 60%RH, and wind speed 0.2m / s. The environment is more humid and the wind speed is slower, so the drying rate is reduced, and therefore the target impeller type shell needs to be dried until the moisture content of the dried target impeller type shell is within the target moisture content range, and the corresponding moisture content sampling interval is from the initial moisture content to the maximum value of the target moisture content range, i.e., 25%-2.2%. Taking an interval time of 2h as an example, the obtained multiple candidate actual moisture contents are shown in Table 2, which is a table of candidate actual moisture contents changing with sampling drying time under the condition of insufficient drying. The sampling drying time includes the initial time to the compliance time of reaching the target moisture content.

[0088] Table 2

[0089]

[0090] Substituting the data in Table 2 above into formula (1), the drying constant K fitted by the linear regression algorithm is 0.098h -1, the drying constant corresponds to the current basic environment parameter, the drying time expected to reach the target moisture content range under the current environment is calculated by using the fitted drying constant and formula (1). The time t1 to reach the upper limit of 2.2% is 19.5h, and the time t2 to reach the lower limit of 1.8% is 25.8h. Therefore, under the current environment, the target drying time range is 19.5h-25.8h. According to the target moisture content range and the basic drying environment corresponding to the basic drying time range of 15.93h-17.86h.

[0091] For the case of over-drying: after 16.8h, the measured moisture content of the target impeller shell is 1.5% (less than the minimum value of the target moisture content range 1.8%-2.2%), the current drying environment parameters are temperature 28℃, humidity 40% RH, and wind speed 0.8m / s, the environment is drier and the wind speed is faster, so the drying rate is improved, therefore, the target impeller shell does not need to be dried further, and the time point when the actual moisture content of the target impeller shell just drops to the lower limit of the target moisture content range 1.8% is directly traced back to the drying process, and the corresponding moisture content sampling interval is from the initial moisture content to the minimum value of the target moisture content range, i.e. 25%-1.8%. Taking an interval time of 2h as an example, the obtained multiple candidate actual moisture contents are shown in Table 3, which is a table showing the change of candidate actual moisture content with sampling drying time under the condition of over-drying. The sampling drying time includes the initial time, the time to reach the target moisture content, and the drying time exceeding the target moisture content.

[0092] Table 3

[0093]

[0094] Substitute the data in Table 3 above into formula (1), and use the linear regression algorithm to fit the drying constant K=0.21h -1 , the drying constant corresponds to the current basic environment parameter, the drying time expected to reach the target moisture content range under the current environment is calculated by using the fitted drying constant and formula (1). The time t1 to reach the upper limit of 2.2% is 19.5h, and the time t2 to reach the lower limit of 1.8% is 25.8h. Therefore, under the current environment, the target drying time range is 19.5h-25.8h. According to the target moisture content range and the basic drying environment corresponding to the basic drying time range of 15.93h-17.86h.

[0095] Compared with the determination of drying quality according to the drying time known by the traditional method, the application determines the drying time according to the drying quality, and reversely adapts the environmental parameters with the shell quality as the anchor point: firstly, the mapping relationship between the moisture content and the shell quality is determined through a large number of reference impeller shell, to determine the target moisture content quality standard which does not change with the environment; secondly, a single target impeller shell is used as an "environmental probe", and the drying model is optimized according to the actual moisture content of the basic drying time of the single target impeller shell, to quickly obtain the adaptive parameters of the current environment; finally, the drying time determined by the optimized model is reused for similar products, without the need to repeat a large number of tests for each environment, while ensuring the consistency of the shell quality, greatly reducing the research and production cost of multi-environment adaptation, and solving the pain points of the traditional method, such as high cost, low quality of the dried shell, insufficient consistency, and inability to adapt to the environment.

[0096] In addition, considering that different layer film processes and effects are different in the actual shell making process, as a more preferred embodiment, the drying time can be determined layer by layer. The surface layer, as the innermost layer directly attached to the wax mold, needs to consider both the smoothness and the bonding strength, and the drying time is too long to easily brittle and crack, so it is shortened according to the first proportion parameter, such as a proportion coefficient of 0.5; the sealing layer, as the outermost layer, its core function is to seal and shape, and the drying degree has less effect on the size of the casting, and it needs to be quickly shaped to avoid damage during transportation, so a larger second proportion parameter is used to shorten the time, such as a proportion coefficient of 0.8; the middle layer, as the shell bearing layer, has the largest thickness of slurry and needs to be fully dried to ensure stiffness, so the drying time is kept unchanged, such as a proportion coefficient of 1.0. By differentiating the drying time of each layer of the shell, the casting yield can be further improved, and the overall shell making cycle can be shortened.

[0097] As described above, the determination of the target shell quality and the target moisture content is the standard for measuring whether the drying time is reasonable and whether the drying process meets the standard, and the determination of the target shell quality and the target moisture content directly determines the precision and surface finish of the impeller casting. As shown in Table 1, the shell quality includes defect probabilities corresponding to each defect type of the shell, and as an optional embodiment of step S120, as shown in Table 2, the target moisture content corresponding to the target shell quality in the mapping relationship includes: Figure 4

[0098] In step S121, weights are assigned to each defect type of the shell corresponding to the moisture content in the mapping relationship;

[0099] In step S122, the weighted sum corresponding to the moisture content is determined according to the defect probabilities of each defect type and the assigned weights, and the weighted sum is taken as the shell quality, to obtain the shell quality corresponding to each moisture content;

[0100] ​In step S123, the lowest weighted sum is taken as the target shell quality, and the moisture content corresponding to the target shell quality is taken as the target moisture content.

[0101] As can be seen from the distribution trend in Table 1, the probability of occurrence of a defect type does not have a fixed upward or downward trend with the moisture content. For a low moisture content, such as 1%, the occurrence rate of defects such as shell cracking, cracking, and layering is high due to over-drying. For a high moisture content, such as 5%, the occurrence rate of defects such as burr / stick sand, clip iron / impurities, and shell expansion is high due to insufficient drying. Therefore, it is necessary to determine the sensitivity of the occurrence probability of each defect type to the moisture content, and after assigning weights to the occurrence probability of each defect type according to the sensitivity, the weighted sum of the weights and the probabilities is taken as the shell quality, and the lowest shell quality is taken as the target shell quality, and the moisture content corresponding thereto is taken as the target moisture content. As an optional implementation of step S121, as shown in Table 2, the weights assigned to each defect type of the shell corresponding to the moisture content in the mapping relationship include: Figure 5

[0102] In step S121a, the average probability is determined according to the defect probability of the defect type at each moisture content in the mapping relationship;

[0103] In step S121b, the standard deviation of the probability is determined according to the defect probability of the defect type at each moisture content in the mapping relationship;

[0104] In step S121c, the standard deviation of the probability is divided by the average probability to obtain the moisture content sensitivity of the defect type;

[0105] In step S121d, the weight is assigned to the defect type according to the moisture content sensitivity; wherein the higher the moisture content sensitivity, the higher the weight assigned to the corresponding defect type.

[0106] Specifically, the process of obtaining the target shell quality and the target moisture content according to the mapping relationship in Table 1 is as follows: In order to facilitate quantitative analysis, the intermediate values of each probability in Table 1 are taken to obtain Table 4 as follows, in Table 4, the unit of moisture content is %, and the unit of the occurrence probability of all defect types is %, and the % symbol is omitted in the table to simplify the presentation.

[0107] Table 4

[0108]

[0109] ​According to the mean and standard deviation of the probability of each defect type occurring at different moisture contents, the moisture content sensitivity is obtained. For example, the mean of the probability of the burr defect type occurring at different moisture contents is (2+3.5+11.5+25+55) / 5=19.4, and the standard deviation is 22.5; and the moisture content sensitivity of each defect type is obtained in the same way, as shown in Table 5. Table 5 describes the moisture content sensitivity and weight corresponding to each defect type.

[0110] Table 5

[0111]

[0112] The higher the moisture content sensitivity, the higher the weight. According to the weight corresponding to each defect type in Table 5 and the weighted sum of the probability of each defect type occurring at different moisture contents in Table 4, the shell mass corresponding to the moisture content is obtained. For example, in Table 4, the shell mass corresponding to a moisture content of 1% is 2.0x9+1.25x10+22.5x9+22.5x7+0.55x10+25.0x8+0.20x9+6.0x8=645.8, and the relationship between different moisture contents and shell masses is shown in Table 6. Table 6 illustrates the relationship between different moisture contents and shell masses.

[0113] Table 6

[0114]

[0115] According to Table 6 above, at a moisture content of 2%, the combined effect of various defects on the shell is the smallest, and the total mass evaluation value is 341.25, so the shell mass at this state is set as the target shell mass, and the corresponding target moisture content is 2%.

[0116] More specifically, one of the moisture content calculation methods of the present application is as formula (2):

[0117] (2)

[0118] wherein, is the moisture content; is the weight of the shell before drying, is the weight of the shell after drying.

[0119] The drying time determination method for the impeller shell provided by the present application can also divide the impeller shell into different parts, such as "recesses, holes, thin-walled parts", which are more difficult to dry than "flat surfaces" (water is easy to stay, easy to cause cracks, loose defects, etc.), and by establishing a mapping relationship between the moisture content and the part shell mass of different parts, the drying time of each part can be further refined and adjusted regionally. Similarly, the method provided by the present application is also applicable to the shell making process of complex castings such as pump bodies and valve bodies, and has universality.

[0120] As a second aspect of the present application, there is provided an electronic device, such as Figure 6 as shown, comprising:

[0121] one or more processors 101;

[0122] a memory 102 having stored thereon one or more computer programs which, when executed by the one or more processors 101, cause the one or more processors 101 to carry out the drying time determination method according to the first aspect of the present application.

[0123] The tool can further comprise one or more I / O interfaces 103 connected between the processor 101 and the memory 102 and configured to enable information interaction between the processor 101 and the memory 102.

[0124] wherein the processor 101 is a device having data processing capability, including but not limited to a central processing unit 101 (CPU) and the like; the first memory 102 is a device having data storage capability, including but not limited to a random access memory 102 (RAM, more specifically SDRAM, DDR, and the like), a read-only memory 102 (ROM), an electrically erasable programmable read-only memory 102 (EEPROM), a flash memory (FLASH); the I / O interface 103 (read-write interface) is connected between the processor 101 and the memory 102 and can enable information interaction between the processor 101 and the memory 102, including but not limited to a data bus 104 (Bus) and the like.

[0125] In some embodiments, the processor 101, the memory 102, and the I / O interface 103 are connected to each other through the bus 104, and further connected to other components of the computing device.

[0126] Further, as a third aspect of the present application, there is provided a computer readable medium having stored thereon a computer program which, when executed by a processor, implements the drying time determination method according to the first aspect of the present application.

[0127] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program. Accordingly, the computer program can be stored in a non-volatile computer readable storage medium, and when the computer program is executed, the method of any one of the above embodiments can be implemented. In the embodiments provided in the present application, any reference to memory, storage, database or other medium can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration but not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM) and memory bus dynamic RAM (RDRAM), etc.

[0128] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto. Those skilled in the art should understand that the present application includes but is not limited to the contents described in the above specific embodiments and the accompanying drawings. Any modification that does not deviate from the functional and structural principles of the present application will be included in the scope of the claims.

Claims

1. A method for determining the drying time of an impeller-shaped shell, characterized in that, The method for determining the drying time includes: Obtain the mapping relationship between water content and the shell mass of the reference impeller shell; The target water content corresponding to the target shell mass is determined in the mapping relationship; The basic drying time of the target impeller shell is determined based on the initial moisture content of the target impeller shell at the initial time, the target moisture content, and the drying model corresponding to the basic drying environment. The drying model is optimized based on the actual moisture content of the target impeller shell during the basic drying time until the actual moisture content of the target impeller shell is consistent with the target moisture content, thus obtaining a drying model corresponding to the current drying environment. The target drying time for similar impeller shells is determined using the obtained drying model under the current drying environment.

2. The method for determining drying time according to claim 1, characterized in that, The drying model includes drying parameters; The process of optimizing the drying model based on the actual moisture content of the target impeller shell during the initial drying time, until the actual moisture content of the target impeller shell matches the target moisture content, yields a drying model corresponding to the current drying environment, including: The target moisture content range is determined based on the preset moisture content window and the target moisture content. If the actual moisture content of the target impeller shell is detected to be within the target moisture content range during the basic drying time, the drying model will be used as the drying model corresponding to the current drying environment. If the actual moisture content of the target impeller shell during the basic drying time is not within the target moisture content range, the drying parameters of the drying model are fitted using the initial moisture content and the target moisture content, and the fitted drying parameters are used as the drying parameters of the drying model corresponding to the current drying environment.

3. The method for determining drying time according to claim 2, characterized in that, The process of fitting the drying parameters of the drying model using the initial moisture content and the target moisture content, and using the fitted drying parameters as the drying parameters of the drying model corresponding to the current drying environment, includes: Determine the moisture content sampling interval based on the initial moisture content and the target moisture content range; Within the moisture content sampling range, multiple candidate actual moisture contents are obtained at intervals; The candidate actual moisture content corresponding to multiple time intervals is substituted into the drying model, and the drying parameters of the drying model are fitted using a linear regression algorithm.

4. The method for determining drying time according to any one of claims 1 to 3, characterized in that, The drying model satisfies the following formula (1): (1) in, The initial water content of the target impeller shell at the initial time; t represents time; M(t) is the water content of the target impeller shell at time t; K is the drying constant of the drying model. Under the basic drying environment, K is the drying constant of the drying model corresponding to the basic drying environment; under the current drying environment, K is the drying constant of the drying model corresponding to the current drying environment; wherein, at least one of the temperature, humidity and wind speed in the current drying environment is different from that in the basic drying environment.

5. The method for determining drying time according to any one of claims 1 to 3, characterized in that, The target impeller shell comprises multiple film layers, and the method for determining the drying time further includes: Given a target drying time for a similar impeller shell, the target drying time is adjusted based on the position of the film on the target impeller shell. When the film is the surface layer of the target impeller shell, the determined target drying time is reduced according to the first proportional parameter; wherein, the surface layer is the film located at the innermost layer of the target impeller shell; When the film is a sealing layer of the target impeller shell, the determined target drying time is reduced according to the second proportional parameter; wherein, the sealing layer is the outermost film located on the target impeller shell; the second proportional parameter is greater than the first proportional parameter; With the film layer located between the surface layer and the sealing layer of the target impeller shell, the determined target drying time is maintained.

6. The method for determining drying time according to claim 1, characterized in that, The shell quality includes the defect probability corresponding to each defect type of the shell; Determining the target water content corresponding to the target shell mass in the mapping relationship includes: Assign weights to each defect type of the shell corresponding to the moisture content in the mapping relationship; The weighted sum corresponding to the moisture content is determined based on the defect probability and assigned weight of each defect type, and the weighted sum is used as the shell mass to obtain the shell mass corresponding to multiple moisture contents. The lowest weighted sum is taken as the target shell mass, and the moisture content corresponding to the target shell mass is taken as the target moisture content.

7. The method for determining drying time according to claim 6, characterized in that, The process of assigning weights to each defect type of the shell corresponding to the moisture content in the mapping relationship includes: The average probability is determined based on the defect probability at each moisture content in the mapping relationship according to the defect type; The probability standard deviation is determined based on the defect probability at each moisture content in the mapping relationship according to the defect type; Divide the probability standard deviation by the probability mean to obtain the moisture content sensitivity of the defect type; Defect types are assigned weights based on the moisture content sensitivity; where the higher the moisture content sensitivity, the higher the weight assigned to the corresponding defect type.

8. The method for determining drying time according to any one of claims 1 to 3, characterized in that, The moisture content satisfies the following formula (2): （2） in, Moisture content; This is the weight of the shell before drying. This is the weight of the dried shell.

9. An electronic device, characterized in that, include: One or more processors; A memory having stored one or more computer programs that, when executed by one or more processors, cause the one or more processors to implement the drying time determination method according to any one of claims 1 to 8.

10. A computer-readable medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the drying time determination method according to any one of claims 1 to 8.

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