Control method for a cold isostatic pressing device

Abstract

The present application relates to the field of material processing technology, through multi-parameter cooperative monitoring, the stable control of dynamic adjustment of pressurizing, pressure maintaining and pressure releasing stages is realized, so as to improve the control efficiency of the cold isostatic pressing device, and particularly relates to a control method of the cold isostatic pressing device; the present application is helpful to ensure no leakage and correct material placement through the detection from "surface inspection" to "intrinsic characteristics", and the pressure in the high-pressure bin is smoothly increased according to the standard pressure increasing rate and the standard real-time pressure value, and accompanied by the segmented pressure maintaining process, that is, through the stage-by-stage adjustment of the control precision and strategy, the whole cycle demand of the material from the rapid densification to the stress release is matched, the problems of "over-densification" or "insufficient densification" caused by the traditional constant pressure maintaining are solved, and the pressure releasing is managed in real time, and then the return rate of the hydraulic oil is controlled, so as to avoid the material damage caused by the too fast rate of the high-pressure section, and shorten the overall pressure reducing time.

Description

Technical Field

[0001] This invention relates to the field of materials processing technology, and in particular to a control method for a cold isostatic pressing device. Background Technology

[0002] Cold isostatic pressing (CIP) technology applies isotropic pressure to materials within a closed mold using a liquid medium to achieve material densification. It is widely used in ceramics, metal powders, composite materials, and other fields. During the CIP process, the precision of pressure and temperature control directly affects the quality of the product, such as density uniformity and mechanical properties.

[0003] Currently, traditional cold isostatic pressing (COP) control methods mostly use fixed pressurization rates, holding times, and depressurization rates, which are difficult to dynamically adjust according to actual pressure and temperature changes. When the pressure or temperature inside the device fluctuates, it can easily lead to defects such as cracks and uneven density in the product, reducing the product qualification rate.

[0004] To address the aforementioned technical shortcomings, a solution is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a control method for a cold isostatic pressing device to solve the aforementioned technical defects. This invention achieves stable control and safe processing of the cold isostatic pressing device through segmented monitoring.

[0006] The objective of this invention can be achieved through the following technical solution: a control method for a cold isostatic pressing device, comprising the following steps:

[0007] Step 1: Load the material to be processed into a sealed elastic mold, place it into the high-pressure chamber of the cold isostatic pressing device, and perform self-inspection and feedback analysis on the sealing status and material placement of the high-pressure chamber to obtain pressure increase command or fault command.

[0008] Step 2: Pressurization stage: Start the pressurization system, control the hydraulic pump through the servo motor to deliver hydraulic oil to the pressurizer, pressurize it and send the high-pressure liquid into the high-pressure chamber. At the same time, pressurization monitoring and evaluation analysis are carried out to obtain pressurization stabilization command or verification command.

[0009] Step 3: Pressure Holding Stage: Based on the pressure stabilization command and after the pressure in the high-pressure chamber reaches the set target pressure value, the pressure is kept stable, so that the material is subjected to isostatic pressing under stable high pressure, accompanied by a pressure holding segment management and analysis process.

[0010] Step 4: Depressurization Stage: After the pressure holding is completed, the depressurization operation begins;

[0011] Step 5: Material Removal Stage: After the pressure inside the high-pressure chamber drops to atmospheric pressure, open the high-pressure chamber and remove the material that has undergone cold isostatic pressing treatment, completing one cold isostatic pressing process.

[0012] Preferably, the self-inspection feedback analysis process for the sealing status and material placement is as follows:

[0013] S1: Sealing status detection process;

[0014] S2: Material placement self-inspection process;

[0015] S3: Information Summarization, Feedback, and Analysis Process

[0016] If an airtight signal, a normal signal, and a uniform signal are generated simultaneously, a pressurization command is obtained; if these three signals are not generated simultaneously, a fault command is obtained.

[0017] Preferably, S1 further includes S11: detecting the pre-tightening torque of the locking bolt by a torque sensor installed on the door locking mechanism, and monitoring the fitting gap between the door and the body by a displacement sensor, and processing the pre-tightening torque and fitting gap to obtain a sealing signal or an unsealed signal;

[0018] S12: Based on the sealing signal, inject hydraulic medium into the pressure chamber, obtain the pressure change in the chamber within a preset time t, where t is a natural number greater than zero, and determine whether the pressure change exceeds the preset pressure change threshold. If yes, generate a sealing failure signal; otherwise, generate an airtight signal.

[0019] Preferably, S2 further includes S21: recording the weight of the empty bin bottom before the mold is placed in, and automatically calculating the total weight G of the mold and material after the mold is placed in;

[0020] S22: Obtain the standard self-weight of the mold and the preset filling weight range of the corresponding material. Obtain whether the value obtained by subtracting the standard self-weight from the total weight G belongs to the preset filling weight range. If yes, generate a normal signal; otherwise, generate an abnormal signal.

[0021] S23: After the mold is placed in place, the low-frequency sinusoidal vibration applied by the electromagnetic vibrator on the side wall of the chamber is collected in real time by the piezoelectric acceleration sensor attached to the surface of the mold, generating a vibration spectrum diagram. The vibration spectrum diagram is compared and analyzed with the preset vibration spectrum diagram to obtain the similarity between the two. At the same time, the ultrasonic attenuation is obtained by symmetrically installing ultrasonic sensors at the top and bottom of the high-pressure chamber. The similarity and ultrasonic attenuation are discriminated to obtain a non-uniform signal or a uniform signal.

[0022] Preferably, the pressurization monitoring and assessment analysis process is as follows: obtain the health information of the booster during the pressurization process, including operating current, unit energy consumption, etc., input the health information into a pre-set health assessment model, obtain the booster health score output by the health assessment model, and determine whether the booster health score exceeds the preset booster health score threshold. If it does, generate a progressive signal; if not, generate a risk instruction.

[0023] Preferably, when a progressive signal is generated, the pressurization rate and real-time pressure value in the high-pressure chamber during the pressurization process are obtained. Based on the time series, a pressurization rate characteristic curve and a real-time pressure value characteristic curve are constructed. The overlapping parts of the pressurization rate characteristic curve and the real-time pressure value characteristic curve with the preset standard pressurization rate characteristic curve and the standard real-time pressure value characteristic curve are respectively set as pressurization fit degree and pressure fit degree. The pressurization fit degree and the pressure fit degree are judged and processed to obtain a pressurization stabilization command or a verification command.

[0024] Preferably, the pressure holding segment management and analysis process is as follows: read the real-time pressure value P_final and temperature value T_final at the end of the pressurization stage; perform discrimination processing on the real-time pressure value P_final and temperature value T_final to obtain feedback signals or fine-tuning signals;

[0025] When a feedback signal is generated, the pressure holding stage is divided into the initial pressure holding stage, the middle pressure holding stage, and the final pressure holding stage.

[0026] Preferably, in the initial stage of pressure holding: the real-time pressure Pactual, maximum temperature difference ΔTmax, and radial deformation rate of the mold in the high-pressure chamber are obtained during the pressure holding stage. The real-time pressure Pactual, maximum temperature difference ΔTmax, and radial deformation rate of the mold are collectively referred to as key parameters. The key parameters are then processed for discrimination. If an alarm signal is obtained, the alarm signal comparison process is set as an anomaly comparison. The alarm signal + anomaly comparison is set as an alarm report. Based on the alarm report, a pre-stored solution is obtained.

[0027] Mid-pressure holding stage: Obtain pressure compensation information and material stress information in the high-pressure chamber during the pressure holding stage. The pressure compensation information is the pressure value at the last acquisition time minus the pressure value at the current acquisition time; the material stress information is the value calculated from the difference between the radial stress and axial stress inside the material collected by the pre-embedded stress sensor.

[0028] The pressure compensation information and material stress information are processed to obtain a preset pressure compensation rate step curve or pressure adjustment command.

[0029] At the end of the pressure holding period: stop active pressure replenishment. When the real-time pressure P is less than the preset standard value, start the preset minimum rate pressure replenishment. At the same time, collect the current average shrinkage rate of the material and process the average shrinkage rate to obtain the pressure relief rate curve of the delay command or process command.

[0030] Preferably, the depressurization operation process is as follows: the pressure value of the hydraulic oil in the high-pressure chamber is obtained, and the pressure value in the chamber is processed to obtain the high-pressure section, medium-pressure section and low-pressure section, and then the set depressurization rate corresponding to the high-pressure section, medium-pressure section and low-pressure section is obtained.

[0031] Based on the current pressure value inside the chamber, the current set pressure relief rate and the actual pressure relief rate are obtained. If the actual pressure relief rate is less than the set pressure relief rate, an opening increase signal is generated. If the actual pressure relief rate is greater than or equal to the set pressure relief rate, an opening decrease signal is generated.

[0032] The beneficial effects of this invention are as follows:

[0033] (1) This invention conducts safety monitoring and analysis on the sealing and material placement of the cold isostatic pressing device, that is, from "surface inspection" to "internal characteristics" detection, which helps to ensure no leakage and correct material placement. At the same time, through vibration response, ultrasonic penetration and other means, it indirectly reflects the internal filling state of the material, so as to prompt the operator to handle according to the information feedback.

[0034] (2) This invention monitors the pressure from the perspective of pressurization safety, thereby controlling the amount and pressure of hydraulic oil discharged by the hydraulic pump, so that the pressure in the high-pressure chamber rises steadily according to the standard pressurization rate and standard real-time pressure value, accompanied by a segmented pressure holding process. That is, by adjusting the control precision and strategy in stages, it matches the full cycle requirements of the material from rapid densification to stress release, solving the problem of "over-densification" or "insufficient densification" caused by traditional constant pressure holding. At the same time, it manages the pressure relief in real time, thereby controlling the return rate of hydraulic oil, which avoids material damage caused by excessively fast high-pressure section and shortens the overall pressure reduction time. Attached Figure Description

[0035] The invention will now be further described with reference to the accompanying drawings;

[0036] Figure 1 This is a reference diagram of the method of the present invention;

[0037] Figure 2 This is a partial analytical diagram of Embodiment 1 of the present invention;

[0038] Figure 3 This is a reference schematic diagram of the material placement self-inspection process of the present invention. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments;

[0041] Example 1: Please refer to Figures 1 to 3 As shown, the present invention is a control method for a cold isostatic pressing device, comprising the following steps:

[0042] Step 1: Load the material to be processed into a sealed elastic mold, place it into the high-pressure chamber of the cold isostatic pressing device, and perform self-inspection and feedback analysis on the sealing status and material placement of the high-pressure chamber to obtain pressure increase command or fault command.

[0043] Step 2: Pressurization stage: Start the pressurization system, control the hydraulic pump through the servo motor to deliver hydraulic oil to the pressurizer, pressurize it and send the high-pressure liquid into the high-pressure chamber. At the same time, pressurization monitoring and evaluation analysis are carried out to obtain pressurization stabilization command or verification command.

[0044] Step 3: Pressure Holding Stage: Based on the pressure stabilization command and after the pressure in the high-pressure chamber reaches the set target pressure value, the pressure is kept stable, so that the material is subjected to isostatic pressing under stable high pressure, accompanied by a pressure holding segment management and analysis process.

[0045] Step 4: Depressurization Stage: After the pressure holding is completed, the depressurization operation begins;

[0046] Step 5: Material Removal Stage: After the pressure inside the high-pressure chamber drops to atmospheric pressure, open the high-pressure chamber and remove the material that has undergone cold isostatic pressing treatment, completing one cold isostatic pressing process;

[0047] The material to be processed is loaded into a sealed elastic mold and placed into the high-pressure chamber of the cold isostatic pressing device. The sealing status of the high-pressure chamber and the material placement are detected by sensors. The self-check feedback analysis of the sealing status and material placement is used to obtain pressure increase command or fault command, which helps to ensure no leakage and correct material placement. If a fault command is detected, the system issues an alarm and stops subsequent operations, prompting the operator to handle the situation.

[0048] The self-inspection feedback analysis process for sealing status and material placement is as follows:

[0049] S1: Sealing condition detection process:

[0050] S11: The pre-tightening torque of the locking bolt is detected by a torque sensor installed on the door locking mechanism. At the same time, the fitting gap between the door and the body is monitored by a displacement sensor. The pre-tightening torque and the fitting gap are judged and processed. If the pre-tightening torque reaches the preset threshold and the fitting gap is less than the preset fitting gap threshold, a sealing signal is generated. If the pre-tightening torque does not reach the preset threshold, or the fitting gap is greater than or equal to the preset fitting gap threshold, an unsealed signal is generated. The unsealed signal is responded to and the corresponding operation is performed to prompt the operator to handle the situation.

[0051] S12: Based on the sealing signal, inject hydraulic medium into the pressure chamber, obtain the pressure change in the chamber within a preset time t, where t is a natural number greater than zero, and determine whether the pressure change exceeds the preset pressure change threshold. If so, generate a sealing failure signal; otherwise, generate an airtight signal.

[0052] This process avoids the risk of high-pressure leakage through low-pressure pre-detection;

[0053] S2: Material placement self-inspection process:

[0054] S21: Record the weight of the empty bin bottom before placing the mold, and automatically calculate the total weight G of the mold and material after placing the mold;

[0055] S22: Obtain the standard self-weight of the mold and the preset filling weight range of the corresponding material. Obtain whether the value obtained by subtracting the standard self-weight from the total weight G belongs to the preset filling weight range. If yes, generate a normal signal; otherwise, generate an abnormal signal.

[0056] S23: After the mold is placed in place, the low-frequency sinusoidal vibration applied by the electromagnetic vibrator on the side wall of the chamber is collected in real time by the piezoelectric accelerometer attached to the surface of the mold, generating a vibration spectrum. The vibration spectrum is compared and analyzed with the preset vibration spectrum to obtain the similarity between the two. At the same time, the ultrasonic attenuation is obtained by ultrasonic sensors symmetrically installed at the top and bottom of the high-pressure chamber. The similarity and ultrasonic attenuation are judged. If the similarity is less than the preset similarity threshold, or the ultrasonic attenuation is greater than the preset ultrasonic attenuation threshold, a non-uniform signal is generated. If the similarity is greater than or equal to the preset similarity threshold, and the ultrasonic attenuation is less than or equal to the preset ultrasonic attenuation threshold, a uniform signal is generated.

[0057] S3: Information Summarization, Feedback, and Analysis Process

[0058] If an airtight signal, a normal signal, and a uniform signal are generated simultaneously, a pressurization command is obtained. If an airtight signal, a normal signal, and a uniform signal are not generated simultaneously, a fault command is obtained. The fault command is responded to and the corresponding operation is executed to prompt the operator to handle the situation.

[0059] In this embodiment of the invention, the detection method shifts from "surface inspection" to "internal characteristics": existing technologies often rely on manual observation of whether the mold is full or simply weighing to determine the filling amount, which cannot identify problems such as internal voids and uneven density; this method indirectly reflects the internal filling state of the material through vibration response, ultrasonic penetration, and other means.

[0060] Example 2: Step 2: Pressurization Stage: When a pressurization command is generated, the pressurization system is started. The hydraulic pump is controlled by a servo motor to deliver hydraulic oil to the pressurizer. After being pressurized by the pressurizer, the high-pressure liquid is sent into the high-pressure chamber. At the same time, pressurization monitoring and evaluation analysis are performed to obtain a pressurization stabilization command or verification command. The specific pressurization monitoring and evaluation analysis process is as follows:

[0061] The system acquires health information of the turbocharger during the boosting process, including operating current and unit energy consumption. This health information is then input into a pre-set health assessment model to obtain a boosting health score. The system then determines whether the boosting health score exceeds a preset boosting health score threshold. If it does, a progressive signal is generated; otherwise, a risk command is generated, and the corresponding preset warning operation is immediately executed. This allows for targeted management of the turbocharger based on information feedback, ensuring the stability and reliability of the boosting process.

[0062] When a progressive signal is generated, the pressurization rate and real-time pressure value within the high-pressure chamber during the pressurization process are acquired. Based on the time series, a pressurization rate characteristic curve and a real-time pressure value characteristic curve are constructed. These curves are then overlaid with preset standard pressurization rate and real-time pressure value characteristic curves. The overlapping portions of these curves are designated as the pressurization fit and pressure fit, respectively. The pressurization fit and pressure fit are then analyzed. The force fit is judged and processed. If the pressure fit is greater than or equal to the pressure fit threshold and the pressure fit is greater than or equal to the preset pressure fit threshold, a pressure increase and stabilization command is generated. If the pressure fit is less than the pressure fit threshold or the pressure fit is less than the preset pressure fit threshold, a verification command is generated. The system responds immediately to the verification command and precisely adjusts the speed and torque of the servo motor through the servo motor controller, thereby controlling the discharge volume and discharge pressure of the hydraulic pump, so that the pressure in the high-pressure chamber rises steadily according to the standard pressure increase rate and standard real-time pressure value.

[0063] Example 3: Pressure Holding Stage: Based on the pressure stabilization command and after the pressure inside the high-pressure chamber reaches the set target pressure value, the pressure is maintained stable, allowing the material to undergo isostatic pressing under stable high pressure, accompanied by a pressure holding segment management and analysis process:

[0064] Read the real-time pressure value P_final and temperature value T_final at the end of the pressurization phase;

[0065] The system performs discrimination processing on the real-time pressure value P_final and the temperature value T_final. If the real-time pressure value P_final is within the preset real-time pressure value range and the temperature value T_final is within the preset temperature value range, a feedback signal is generated. If the real-time pressure value P_final is not within the preset real-time pressure value range or the temperature value T_final is not within the preset temperature value range, a fine-tuning signal is generated. The system responds to the fine-tuning signal by performing pressure replenishment / depressurization operations or heating / cooling operations.

[0066] When a feedback signal is generated, the pressure holding stage is divided into the initial pressure holding stage, the middle pressure holding stage, and the final pressure holding stage.

[0067] Initial pressure holding phase: The real-time pressure Pactual, maximum temperature difference ΔTmax, and radial deformation rate of the mold in the high-pressure chamber are obtained during the pressure holding phase. These parameters are collectively referred to as key parameters. The key parameters are then processed for judgment. If at least one of the following occurs: real-time pressure Pactual is less than the minimum value in the preset real-time pressure range, or real-time pressure Pactual is greater than the maximum value in the preset real-time pressure range, or maximum temperature difference ΔTmax is greater than the preset maximum temperature difference threshold, or radial deformation rate of the mold is greater than the preset radial deformation rate threshold, an alarm signal is generated. The comparison process corresponding to the alarm signal is set as an anomaly comparison, and the alarm signal + anomaly comparison is set as an alarm report. Based on the alarm report, a pre-stored solution is obtained, and then the pre-stored solution is executed to adjust the parameters in the key parameters.

[0068] For example: Alarm report: If the alarm signal + real-time pressure P is less than the minimum value in the preset real-time pressure range, then the pre-stored solution is to open the micro-pressure relief valve; Alarm report: If the alarm signal + maximum temperature difference ΔTmax is greater than the preset maximum temperature difference threshold, then the pre-stored solution is to open the temperature equalization stirring device to make the temperature in the high-pressure chamber uniform, and so on.

[0069] Mid-pressure holding stage: Obtain pressure compensation information and material stress information within the high-pressure chamber during the pressure holding stage;

[0070] Pressure compensation information represents the pressure value at the last acquisition time minus the pressure value at the current acquisition time;

[0071] Material stress information is represented by the value calculated from the difference between the radial and axial stresses inside the material, which are collected by pre-embedded stress sensors.

[0072] The pressure compensation information and material stress information are processed and judged. If the pressure compensation information is greater than the preset pressure compensation information, the preset pressure compensation rate step curve is obtained, and the pressure compensation is adjusted according to the preset pressure compensation rate step curve.

[0073] If the material stress information is greater than the preset material stress information, a pressure adjustment command is generated and executed to make the material stress information less than the preset value, thereby reducing the risk of cracking later.

[0074] End of pressure holding period: Stop active pressure replenishment. When the real-time pressure P is less than the preset standard value, start the preset minimum rate pressure replenishment to ensure that the material will not cause structural rebound due to low pressure.

[0075] Simultaneously, the current average shrinkage rate of the material is collected, and the average shrinkage rate is judged. If the average shrinkage rate is less than the minimum value in the preset target shrinkage rate range, a delay command is generated, and pressure holding delay processing is performed in response to the delay command. If the average shrinkage rate is within the preset target shrinkage rate range, a process command is generated, and the process is performed according to the normal process in response to the process command. If the average shrinkage rate is greater than the maximum value in the preset target shrinkage rate range, the difference between the average shrinkage rate and the maximum value in the preset target shrinkage rate range is obtained, and the difference is set as the pressure relief matching value. If the pressure relief matching value is within the corresponding preset pressure relief matching value range, it is set as the pressure relief rate curve, and the pressure relief rate curve is used for pressure relief in the pressure relief stage.

[0076] It should be noted that each preset pressure relief matching value range has a corresponding pressure relief rate curve, and the pressure relief rate curve is different depending on the pressure relief matching value.

[0077] Example 4: In this embodiment of the invention, the core of the depressurization stage is to control the return rate of hydraulic oil by adjusting the opening of the high-pressure chamber drain valve, so that the pressure in the high-pressure chamber decreases steadily at a preset depressurization rate.

[0078] Depressurization Phase: After pressure holding is completed, the depressurization operation begins. The specific depressurization process is as follows:

[0079] The pressure value of the hydraulic oil in the high-pressure chamber is obtained and processed. If the pressure value is greater than the maximum value in the preset pressure range, it is determined to be in the high-pressure section. If the pressure value is within the preset pressure range, it is determined to be in the medium-pressure section. If the pressure value is less than the minimum value in the preset pressure range, it is determined to be in the low-pressure section. The set pressure relief rate corresponding to the high-pressure section, medium-pressure section and low-pressure section is obtained.

[0080] Based on the current pressure value inside the chamber, the current set pressure relief rate and the actual pressure relief rate are obtained. If the actual pressure relief rate is less than the set pressure relief rate, an opening increase signal is generated to increase the opening of the drain valve. If the actual pressure relief rate is greater than or equal to the set pressure relief rate, an opening decrease signal is generated to decrease the opening of the drain valve. This controls the return flow rate of the hydraulic oil, which avoids material damage caused by excessively fast flow in the high-pressure section and shortens the overall pressure reduction time.

[0081] Material removal stage: After the pressure in the high-pressure chamber drops to normal pressure, the high-pressure chamber is opened, and the material that has undergone cold isostatic pressing is removed, completing one cold isostatic pressing process.

[0082] In summary, this invention provides safety monitoring and analysis of the sealing and material placement of the cold isostatic pressing device, from "surface inspection" to "internal characteristic" testing. This helps ensure no leakage and correct material placement. Simultaneously, through vibration response and ultrasonic penetration, it indirectly reflects the internal filling state of the material, providing feedback to operators for appropriate action. From a pressurization perspective, it monitors pressurization safety, controlling the discharge volume and pressure of the hydraulic pump. This ensures the pressure in the high-pressure chamber rises steadily according to the standard pressurization rate and real-time pressure value, accompanied by a segmented pressure holding process. By adjusting the control precision and strategy in stages, it matches the full-cycle requirements of the material from rapid densification to stress release, solving the problems of "over-densification" or "insufficient densification" caused by traditional constant pressure holding. Furthermore, it manages depressurization in real time, controlling the hydraulic oil return rate. This avoids material damage caused by excessively rapid depressurization in the high-pressure section and shortens the overall depressurization time.

[0083] The threshold is set for comparative analysis of results to determine whether they are good or bad. The value of the threshold is determined by a combination of large-scale model analysis of sample data and human experience. It can also be adjusted appropriately based on seasonal or common-sense influencing factors.

[0084] The size of the coefficient is a specific value obtained by quantifying each parameter to facilitate subsequent comparison. The size of the coefficient depends on the amount of sample data and the corresponding operating coefficient initially set by those skilled in the art for each set of sample data; as long as it does not affect the proportional relationship between the parameter and the quantified value.

[0085] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A control method for a cold isostatic pressing device, characterized in that, Includes the following steps: Step 1: Load the material to be processed into a sealed elastic mold, place it into the high-pressure chamber of the cold isostatic pressing device, and perform self-inspection and feedback analysis on the sealing status and material placement of the high-pressure chamber to obtain pressure increase command or fault command. Step 2: Pressurization stage: Start the pressurization system, control the hydraulic pump through the servo motor to deliver hydraulic oil to the pressurizer, pressurize it and send the high-pressure liquid into the high-pressure chamber. At the same time, pressurization monitoring and evaluation analysis are carried out to obtain pressurization stabilization command or verification command. Step 3: Pressure Holding Stage: Based on the pressure stabilization command and after the pressure in the high-pressure chamber reaches the set target pressure value, the pressure is kept stable, so that the material is subjected to isostatic pressing under stable high pressure, accompanied by a pressure holding segment management and analysis process. Step 4: Depressurization Stage: After the pressure holding is completed, the depressurization operation begins; Step 5: Material Removal Stage: After the pressure inside the high-pressure chamber drops to atmospheric pressure, open the high-pressure chamber and remove the material that has undergone cold isostatic pressing treatment, completing one cold isostatic pressing process; The self-inspection feedback analysis process for sealing status and material placement is as follows: S1: Sealing status detection process; S2: Material placement self-inspection process; S3: Information Summarization, Feedback, and Analysis Process If an airtight signal, a normal signal, and a uniform signal are generated simultaneously, a pressurization command is obtained; if an airtight signal, a normal signal, and a uniform signal are not generated simultaneously, a fault command is obtained. S1 also includes S11: the pre-tightening torque of the locking bolt is detected by a torque sensor installed on the door locking mechanism, and the fitting gap between the door and the body is monitored by a displacement sensor. The pre-tightening torque and the fitting gap are processed to obtain a sealing signal or an unsealed signal. S12: Based on the sealing signal, inject hydraulic medium into the pressure chamber, obtain the pressure change in the chamber within a preset time t, where t is a natural number greater than zero, and determine whether the pressure change exceeds the preset pressure change threshold. If so, generate a sealing failure signal; otherwise, generate an airtight signal. S2 also includes S21: Record the weight of the empty bin bottom before the mold is placed in, and automatically calculate the total weight G of the mold and material after the mold is placed in. S22: Obtain the standard self-weight of the mold and the preset filling weight range of the corresponding material. Obtain whether the value obtained by subtracting the standard self-weight from the total weight G belongs to the preset filling weight range. If yes, generate a normal signal; otherwise, generate an abnormal signal. S23: After the mold is placed in place, the low-frequency sinusoidal vibration applied by the electromagnetic vibrator on the side wall of the chamber is collected in real time by the piezoelectric acceleration sensor attached to the surface of the mold, generating a vibration spectrum diagram. The vibration spectrum diagram is compared and analyzed with the preset vibration spectrum diagram to obtain the similarity between the two. At the same time, the ultrasonic attenuation is obtained by symmetrically installing ultrasonic sensors at the top and bottom of the high-pressure chamber. The similarity and ultrasonic attenuation are discriminated to obtain a non-uniform signal or a uniform signal.

2. The control method for a cold isostatic pressing device according to claim 1, characterized in that, The pressurization monitoring and assessment analysis process is as follows: the health information of the booster during the pressurization process is obtained, including operating current, unit energy consumption, etc. The health information is input into the pre-set health assessment model to obtain the booster health score output by the health assessment model. The booster health score is then judged to see if it exceeds the preset booster health score threshold. If it does, a progressive signal is generated; otherwise, a risk instruction is generated.

3. The control method for a cold isostatic pressing device according to claim 1, characterized in that, When a progressive signal is generated, the pressurization rate and real-time pressure value in the high-pressure chamber during the pressurization process are obtained. Based on the time series, a pressurization rate characteristic curve and a real-time pressure value characteristic curve are constructed. The overlapping parts of the pressurization rate characteristic curve and the real-time pressure value characteristic curve with the preset standard pressurization rate characteristic curve and the standard real-time pressure value characteristic curve are set as pressurization fit degree and pressure fit degree, respectively. The pressurization fit degree and the pressure fit degree are then processed to obtain a pressurization stabilization command or a verification command.

4. The control method for a cold isostatic pressing device according to claim 1, characterized in that, The pressure holding segment management and analysis process is as follows: Read the real-time pressure value P_final and temperature value T_final at the end of the pressurization stage; perform discrimination processing on the real-time pressure value P_final and temperature value T_final to obtain feedback signals or fine-tuning signals; When a feedback signal is generated, the pressure holding stage is divided into the initial pressure holding stage, the middle pressure holding stage, and the final pressure holding stage.

5. The control method for a cold isostatic pressing device according to claim 4, characterized in that, Initial pressure holding stage: The real-time pressure Pactual, maximum temperature difference ΔTmax, and radial deformation rate of the mold in the high-pressure chamber are obtained during the pressure holding stage. The real-time pressure Pactual, maximum temperature difference ΔTmax, and radial deformation rate of the mold are collectively referred to as key parameters. The key parameters are then processed for discrimination. If an alarm signal is obtained, the alarm signal comparison process is set as an anomaly comparison. The alarm signal + anomaly comparison is set as an alarm report. Based on the alarm report, a pre-stored solution is obtained. Mid-pressure holding stage: Obtain pressure compensation information and material stress information in the high-pressure chamber during the pressure holding stage. The pressure compensation information represents the pressure value at the last acquisition time minus the pressure value at the current acquisition time. Material stress information is represented by the value calculated from the difference between the radial and axial stresses inside the material, which are collected by pre-embedded stress sensors. The pressure compensation information and material stress information are processed to obtain a preset pressure compensation rate step curve or pressure adjustment command. At the end of the pressure holding period: stop active pressure replenishment. When the real-time pressure P is less than the preset standard value, start the preset minimum rate pressure replenishment. At the same time, collect the current average shrinkage rate of the material and process the average shrinkage rate to obtain the pressure relief rate curve of the delay command or process command.

6. The control method for a cold isostatic pressing device according to claim 1, characterized in that, The pressure relief operation process is as follows: the pressure value of the hydraulic oil in the high-pressure chamber is obtained, and the pressure value in the chamber is processed to obtain the high-pressure section, medium-pressure section and low-pressure section, and then the set pressure relief rate corresponding to the high-pressure section, medium-pressure section and low-pressure section is obtained. Based on the current pressure value inside the chamber, the current set pressure relief rate and the actual pressure relief rate are obtained. If the actual pressure relief rate is less than the set pressure relief rate, an opening increase signal is generated. If the actual pressure relief rate is greater than or equal to the set pressure relief rate, an opening decrease signal is generated.

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