Diaphragm pump air tightness detection system

Abstract

The application relates to the technical field of air tightness detection, and discloses a diaphragm pump air tightness detection system. The system comprises a pressure generation module, a pressure detection module and a control module; the pressure generation module is configured to apply positive pressure or negative pressure to an inlet end or an outlet end of a measured diaphragm pump; the pressure detection module is configured to detect pressure information of the inlet end or pressure information of the outlet end of the measured diaphragm pump; the control module is configured to control the pressure generation module to apply positive pressure or negative pressure to the inlet end of the measured diaphragm pump or to apply positive pressure to the outlet end of the measured diaphragm pump, and to generate a corresponding air tightness detection result based on the attenuation amplitude of the pressure information and the pump body type of the measured diaphragm pump. The embodiment of the application can improve the detection efficiency and detection precision of diaphragm pump air tightness detection.

Description

Technical Field

[0001] This application relates to the field of airtightness testing technology, and in particular to an airtightness testing system for diaphragm pumps. Background Technology

[0002] As an important piece of equipment widely used in industrial and agricultural production, the accuracy and convenience of performance testing for miniature diaphragm pumps are particularly crucial. In industrial automation scenarios, the airtightness (external leakage, internal leakage) of miniature diaphragm pumps is a core performance indicator. However, manual or semi-automated airtightness testing in related technologies suffers from low efficiency and data processing lag, failing to meet the real-time quality inspection requirements of mass production. Furthermore, these methods cannot identify micro-leakage signals during testing and lack the ability to locate leak sources. Summary of the Invention

[0003] The purpose of this application is to provide a diaphragm pump air tightness testing system, which aims to improve the testing efficiency and accuracy of diaphragm pump air tightness testing.

[0004] This application provides a diaphragm pump airtightness testing system, including:

[0005] The pressure generating module, connected to the inlet and outlet of the diaphragm pump under test, is configured to apply positive or negative pressure to the inlet or outlet of the diaphragm pump under test.

[0006] The pressure detection module is connected to the inlet and outlet of the diaphragm pump under test and is configured to detect the pressure information at the inlet or outlet of the diaphragm pump under test.

[0007] The control module is configured to control the pressure generating module to apply positive or negative pressure to the inlet end of the diaphragm pump under test or to apply positive pressure to the outlet end of the diaphragm pump under test, and to generate corresponding airtightness test results based on the attenuation magnitude of the pressure information and the pump body type of the diaphragm pump under test.

[0008] In some embodiments, the pressure generating module includes a vacuum generator and a gas source, forming a first gas path, a second gas path, and a third gas path;

[0009] In the first gas path, the gas source and the vacuum generator are connected by a pipeline, and the vacuum generator is connected to the inlet end of the diaphragm pump under test by a pipeline.

[0010] In the second gas path, the gas source is connected to the inlet end of the diaphragm pump under test through a pipeline;

[0011] In the third gas path, the gas source is connected to the outlet end of the diaphragm pump under test via a pipeline;

[0012] The first air passage, the second air passage, and the third air passage are each equipped with at least one pressure regulating valve and at least one switching valve.

[0013] In some embodiments, the pressure detection module includes a first pressure detection device, a flow meter, a second pressure detection device, and a water storage tank, forming a first liquid path and a second liquid path;

[0014] In the first liquid path, the outlet end of the diaphragm pump under test, the first pressure detection device, the flow meter and the water storage tank are connected by a pipeline;

[0015] In the second liquid path, the inlet end of the diaphragm pump under test, the second pressure detection device, and the water storage tank are connected by a pipeline;

[0016] The first liquid path and the second liquid path are each equipped with at least one switching valve.

[0017] In some embodiments, the diaphragm pump air tightness testing system further includes a noise detection device configured to collect noise in a preset frequency band when an external leak is detected at the inlet end of the diaphragm pump under test.

[0018] In some embodiments, before generating the corresponding airtightness test result based on the attenuation magnitude of the pressure information and the pump body type of the diaphragm pump under test, the method further includes:

[0019] Construct type feature information that characterizes the pump body type of the tested diaphragm pump;

[0020] The type feature information is input into a preset pressure decay value prediction model to dynamically determine the corresponding pressure decay threshold based on the pump body type of the diaphragm pump under test; the pressure decay value prediction model is obtained by training a preset support vector machine network based on training feature information.

[0021] In some embodiments, after the pressure generating module applies positive pressure to the inlet of the diaphragm pump under test, the generation of corresponding airtightness test results based on the attenuation magnitude of the pressure information and the pump body type of the diaphragm pump under test includes:

[0022] Obtain a first pressure decay value; the first pressure decay value is the pressure value at the inlet of the diaphragm pump under test when a first preset time has elapsed after applying positive pressure to the inlet of the diaphragm pump under test.

[0023] Determine whether the first pressure attenuation value exceeds a first pressure attenuation threshold; the first pressure attenuation threshold is generated by the pressure attenuation value prediction model.

[0024] If the limit is not exceeded, an airtightness test result indicating that the inlet leakage detection has passed will be generated.

[0025] If the noise level exceeds the preset frequency band noise value, the preset frequency band noise value is obtained by collecting noise from the preset frequency band.

[0026] Determine whether the decibel value of the preset frequency band noise reaches the preset decibel threshold;

[0027] If this is achieved, a leak test result will be generated indicating that there is a visible external leak at the inlet end;

[0028] If the pressure fluctuation information at the inlet of the diaphragm pump under test is not reached, a corresponding airtightness test result is generated based on the pressure fluctuation information at the inlet of the diaphragm pump under test within the first preset time period.

[0029] In some embodiments, generating a corresponding airtightness test result based on the pressure fluctuation information at the inlet of the diaphragm pump under test within the first preset time period includes:

[0030] Wavelet packet decomposition is performed on the pressure fluctuation information to obtain pressure decomposition information;

[0031] Extract pressure fluctuation characteristics of a preset frequency band from the pressure decomposition information;

[0032] Determine whether the pressure fluctuation characteristics meet the preset characteristic fluctuation conditions;

[0033] If the conditions are met, an airtightness test result indicating that the inlet end micro-leakage detection has passed will be generated.

[0034] If it does not meet the requirements, an airtightness test result will be generated indicating a slight external leak at the inlet.

[0035] In some embodiments, after the pressure generating module applies negative pressure to the inlet of the diaphragm pump under test, the generation of corresponding airtightness test results based on the attenuation magnitude of the pressure information and the pump body type of the diaphragm pump under test includes:

[0036] Obtain a second pressure decay value; the second pressure decay value is the root mean square pressure at the inlet of the diaphragm pump under test within a second preset time after a negative pressure is applied to the inlet of the diaphragm pump under test.

[0037] Determine whether the second pressure decay value exceeds the second pressure decay threshold; the second pressure decay threshold is generated by the pressure decay value prediction model.

[0038] If the limit is not exceeded, an airtightness test result indicating that the inlet leakage detection has passed will be generated.

[0039] If the time difference exceeds the limit, the leak source is located using a time difference algorithm. When the leak source is the inlet end of the diaphragm pump under test, an airtightness test result indicating internal leakage at the inlet end is generated.

[0040] In some embodiments, after the pressure generating module applies positive pressure to the outlet end of the diaphragm pump under test, the generation of corresponding airtightness test results based on the attenuation magnitude of the pressure information and the pump body type of the diaphragm pump under test includes:

[0041] Obtain the third pressure decay value; the third pressure decay value is the root mean square pressure at the inlet of the diaphragm pump under test within a third preset time after a positive pressure is applied to the outlet of the diaphragm pump under test.

[0042] Determine whether the third pressure attenuation value exceeds the third pressure attenuation threshold; the third pressure attenuation threshold is generated by the pressure attenuation value prediction model.

[0043] If the limit is not exceeded, an airtightness test result indicating that the internal leakage detection at the outlet end has passed will be generated.

[0044] If the time difference exceeds the limit, the leak source is located using a time difference algorithm. When the leak source is the outlet end of the diaphragm pump under test, an airtightness test result indicating internal leakage at the outlet end is generated.

[0045] In some embodiments, the method of using a time difference algorithm to locate the leakage source includes:

[0046] Determine the time difference between the pressure fluctuations at the inlet and outlet of the diaphragm pump under test;

[0047] The leak source is located based on the time difference of the pressure information fluctuation.

[0048] The beneficial effects of this application are as follows: By dynamically linking pump type characteristics, pressure attenuation amplitude, and airtightness test results, the testing standard can be adaptively adjusted. Unlike fixed testing devices, this system has multi-mode testing capabilities for positive and negative pressure, and can simultaneously complete external and internal leakage detection. It achieves fully automated operation of diaphragm pump airtightness testing, eliminating efficiency bottlenecks caused by manual intervention. The dynamic linking mechanism of pump type characteristics, pressure attenuation amplitude, and airtightness test results effectively solves the compatibility problem of multi-model mixed production lines, and improves the testing efficiency and accuracy of diaphragm pump airtightness testing. Attached Figure Description

[0049] Figure 1 This is a schematic diagram of the structure of the diaphragm pump air tightness testing system provided in the first embodiment of this application.

[0050] Figure 2 This is a schematic diagram of the structure of the diaphragm pump air tightness detection system provided in the second embodiment of this application.

[0051] Figure 3 This is a flowchart of a method for generating airtightness test results provided in the first embodiment of this application.

[0052] Figure 4 This is a flowchart of a method for generating airtightness test results provided in the second embodiment of this application.

[0053] Figure 5 This is a flowchart of a method for generating airtightness test results provided in the third embodiment of this application. Detailed Implementation

[0054] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0055] It should be noted that the terms "first," "second," "third," "fourth," etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a system, product, or device that includes a series of circuits is not necessarily limited to those explicitly listed, but may include other circuits not explicitly listed or inherent to such systems, products, or devices.

[0056] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0057] See Figure 1 In one embodiment, the diaphragm pump airtightness detection system includes a pressure generation module 10, a pressure detection module 20, and a control module 30.

[0058] The pressure generating module 10 is connected to the inlet and outlet of the diaphragm pump under test. The pressure generating module 10 is configured to apply positive or negative pressure to the inlet or outlet of the diaphragm pump. It can be understood that the pressure generating module 10 is a device capable of generating controllable air pressure. Specifically, it can be implemented by combining an air source 12 with a vacuum generator 11. By switching the airflow direction through a solenoid valve, the pressure generating module 10 enables the diaphragm pump airtightness testing system to have dual detection capabilities of positive pressurization and negative pressure suction.

[0059] The pressure detection module 20 is connected to the inlet and outlet of the diaphragm pump under test. The pressure detection module 20 is configured to detect the pressure information at either the inlet or outlet of the diaphragm pump. In essence, the pressure detection module 20 is a device capable of detecting pressure; specifically, it can be implemented using a piezoresistive sensor in conjunction with a data acquisition card. Its function is to accurately capture minute pressure fluctuation signals.

[0060] The control module 30 is configured to control the pressure generation module 10 to apply positive or negative pressure to the inlet of the diaphragm pump under test, or to apply positive pressure to the outlet of the diaphragm pump under test. Based on the attenuation magnitude of the pressure information and the pump body type of the diaphragm pump under test, it generates corresponding airtightness test results. It can be understood that the control module 30 refers to a data processing unit, which can specifically employ an embedded system equipped with a pressure attenuation algorithm. This algorithm dynamically determines the pump body type by establishing a mapping relationship between the pump body type and the pressure threshold, and then generates corresponding airtightness test results based on the attenuation magnitude of the pressure information and the pump body type of the diaphragm pump under test.

[0061] The diaphragm pump airtightness testing system provided in this application embodiment can perform external leakage detection, internal leakage detection, and internal leakage detection at the inlet and outlet of the diaphragm pump under test. In practical applications, the inlet and outlet of the diaphragm pump under test are respectively connected to a pressure generating module 10 and a pressure detection module 20. When performing external leakage detection at the inlet of the diaphragm pump under test, the pressure generating module 10 applies positive pressure to the inlet of the diaphragm pump under test, and the pressure detection module 20 continuously records the pressure information at the inlet of the diaphragm pump under test. When performing internal leakage detection at the inlet of the diaphragm pump under test, the pressure generating module 10 applies negative pressure to the inlet of the diaphragm pump under test, and the pressure detection module 20 continuously records the pressure information at the inlet of the diaphragm pump under test. When performing internal leakage detection at the outlet of the diaphragm pump under test, the pressure generating module 10 applies positive pressure to the inlet of the diaphragm pump under test, and the pressure detection module 20 continuously records the pressure information at the outlet of the diaphragm pump under test. The control module 30 calculates the pressure decay of the corresponding pressure information within a preset time. It then retrieves the corresponding pressure decay threshold based on the pump type of the diaphragm pump being tested. If the pressure decay exceeds the threshold, a failure result is generated for the corresponding airtightness test; otherwise, a pass result is generated. Thus, through the dynamic correlation between pump type characteristics, pressure decay amplitude, and airtightness test results, the testing standard is adaptively adjusted. Unlike fixed testing devices, this system has multi-mode testing capabilities (positive and negative pressure), and can simultaneously complete external and internal leakage detection. This achieves fully automated operation of diaphragm pump airtightness testing, eliminating efficiency bottlenecks caused by manual intervention. The dynamic correlation mechanism between pump type characteristics, pressure decay amplitude, and airtightness test results effectively solves compatibility issues in multi-model mixed-line production, improving the testing efficiency and accuracy of diaphragm pump airtightness testing.

[0062] See also Figure 1 and Figure 2 In one embodiment, the pressure generating module 10 includes a vacuum generator 11 and an air source 12, and the pressure generating module 10 forms a first air path, a second air path, and a third air path. It can be understood that the vacuum generator 11 is a device that generates negative pressure by compressing air, specifically implemented using a venturi tube structure. Its function is to create a negative pressure environment driven by the air source 12, used to apply negative pressure test conditions to the inlet end.

[0063] In the first gas path, the gas source 12 and the vacuum generator 11 are connected via a pipe, and the vacuum generator 11 is connected to the inlet of the diaphragm pump under test via a pipe. In the second gas path, the gas source 12 is connected to the inlet of the diaphragm pump under test via a pipe. In the third gas path, the gas source 12 is connected to the outlet of the diaphragm pump under test via a pipe.

[0064] The first, second, and third air passages are each equipped with at least one pressure regulating valve. Figure 2 (T1 to T3) and at least one switching valve ( Figure 2 (P1 to P3 in the diagram). A pressure regulating valve is a device used to adjust gas pressure, specifically a proportional control valve. Its function is to precisely control the pressure applied to the diaphragm pump according to testing requirements, ensuring the stability of testing conditions. A switching valve is a device that controls the opening and closing of gas paths, specifically a solenoid valve. Its function is to achieve rapid switching between positive and negative pressure application modes by independently controlling the opening and closing of each gas path.

[0065] When negative pressure needs to be applied to the inlet of the diaphragm pump under test, the switch valve on the first gas path is opened, and the gas source 12 drives the vacuum generator 11 to generate negative pressure, which is then transmitted to the inlet of the diaphragm pump under test through the four-way port. When positive pressure needs to be applied to the inlet of the diaphragm pump under test, the switch valve on the second gas path is opened, and the gas source 12 delivers positive pressure gas to the inlet of the diaphragm pump under test through the second gas path and the four-way port. When positive pressure needs to be applied to the outlet of the diaphragm pump under test, the switch valve on the third gas path is opened, and the gas source 12 delivers positive pressure gas to the outlet of the diaphragm pump under test through the third gas path and the three-way port. The pressure regulating valves of each gas path can independently adjust the pressure value. For example, the negative pressure of the first gas path can be set to -90 kPa, and the positive pressure of both the second and third gas paths can be set to 350 kPa to meet the testing requirements. Through the three-gas-path discrete design, the test mode can be quickly switched without disassembling the device under test. Therefore, by using a separate gas path structure, the positive and negative pressure gas paths are completely isolated, eliminating mutual interference during pressure switching. Simultaneously, each gas path is independently equipped with a pressure regulating valve, allowing for real-time adjustment of pressure parameters during testing without interrupting the test process. This enables independent application of different pressure types at the diaphragm pump inlet and outlet, solving the problems of low pressure switching efficiency and unstable test conditions in traditional testing. The three-gas-path parallel structure allows for simultaneous completion of inlet positive pressure external leakage testing, inlet negative pressure internal leakage testing, and outlet positive pressure internal leakage testing, significantly improving testing efficiency. The combined control of the pressure regulating valve and the on / off valve further ensures the accuracy and repeatability of the pressure application process, meeting the diverse testing needs of diaphragm pumps of different specifications.

[0066] See also Figure 1 and Figure 2In one embodiment, the pressure detection module 20 includes a first pressure detection device 21, a flow meter 22, a second pressure detection device 23, and a water storage tank 24. The pressure detection module 20 forms a first liquid path and a second liquid path. The first pressure detection device 21 is a sensor used to detect the liquid pressure at the outlet of the diaphragm pump under test. Specifically, it can be implemented using a piezoelectric pressure sensor, and determines whether there is an internal leak by monitoring changes in the outlet pressure in real time. The flow meter 22 is a device used to measure the liquid flow rate. Specifically, it can be implemented using a turbine flow meter 22, and assists in determining the location of the leak by detecting abnormal liquid flow. The second pressure detection device 23 is a sensor used to detect the liquid pressure at the inlet of the diaphragm pump under test. Specifically, it can be implemented using a strain gauge pressure sensor, and identifies external leaks by comparing the pressure difference between the inlet and outlet. The water storage tank 24 is a container that provides circulating medium for the liquid path. Specifically, it can be implemented using a sealed stainless steel water tank, ensuring the consistency of the detection environment by maintaining the stability of the liquid path medium.

[0067] In the first liquid path, the outlet end of the diaphragm pump under test, the first pressure sensing device 21, the flow meter 22, and the water storage tank 24 are connected by pipes. In the second liquid path, the inlet end of the diaphragm pump under test, the second pressure sensing device 23, and the water storage tank 24 are connected by pipes. Each of the first and second liquid paths is equipped with at least one on / off valve. Figure 2 (P4 and P5 in the text).

[0068] During airtightness testing, the first liquid path connects to the outlet of the diaphragm pump under test via a switch valve and a three-way port, allowing the liquid to flow sequentially through the first pressure detection device 21 and the flow meter 22 before returning to the water storage tank 24. During this time, the first pressure detection device 21 continuously collects the outlet pressure data of the diaphragm pump under test, and the flow meter 22 simultaneously records the liquid flow rate. The second liquid path connects to the inlet of the diaphragm pump under test via a switch valve and a four-way port, allowing the liquid to flow through the second pressure detection device 23 before returning to the water storage tank 24. The second pressure detection device 23 collects the inlet pressure data of the diaphragm pump under test. When the diaphragm pump under test has internal leakage, the pressure fluctuations and flow abnormalities at the outlet of the diaphragm pump under test will be simultaneously detected by the first pressure detection device 21 and the flow meter 22. When external leakage exists, the pressure difference between the inlet and outlet of the diaphragm pump under test is identified through comparative analysis between the second pressure detection device 23 and the first pressure detection device 21. Therefore, by setting up independent first and second fluid paths for pressure testing, simultaneous monitoring of the inlet and outlet pressures of the tested diaphragm pump and cross-verification of flow parameters are achieved, significantly improving the accuracy of leak type identification. Through independent fluid path design and multi-parameter testing, inlet pressure, outlet pressure, and flow data can be acquired simultaneously in a single test, providing multi-dimensional evidence for leak type identification. For example, when the outlet pressure drops but the flow rate does not change significantly, it can be identified as an internal leak; when the inlet and outlet pressures are synchronously abnormal and the flow rate fluctuates, it can be identified as an external leak. Furthermore, the configuration of the switching valve allows for flexible switching of the fluid paths according to testing needs, avoiding the cumbersome operation of manually changing test lines required in traditional testing.

[0069] See also Figure 1 and Figure 2 In one embodiment, the diaphragm pump airtightness testing system further includes a noise detection device 40, configured to collect noise within a preset frequency band when an external leak is detected at the inlet end of the diaphragm pump under test. It is understood that the noise detection device 40 refers to a device for collecting acoustic signals within a specific frequency range, specifically a high-sensitivity microphone or acoustic sensor, used to capture the noise characteristics generated by the leak. Collecting noise within a preset frequency band means directionally collecting acoustic signals within a specific frequency range that may be generated when the diaphragm pump leaks externally. This can be achieved by setting a bandpass filter or a frequency domain analysis algorithm, for example, setting the frequency band to 1kHz to 5kHz to match the typical noise frequency of an external leak in the diaphragm pump.

[0070] When the pressure detection module 20 detects that the pressure at the inlet of the diaphragm pump under test exceeds a preset attenuation threshold, the noise detection device 40 is triggered and starts collecting noise in a preset frequency band. The control module 30 analyzes the collected noise signal to distinguish between overt and minor external leaks. For example, overt external leaks may be accompanied by a significant increase in high-frequency noise, while minor external leaks may manifest as noise fluctuations in a specific frequency band. The combination of data from the noise detection device 40 and the pressure detection module 20 helps determine the type of leak and the location of the leak source. Therefore, by introducing the noise detection device 40 and combining the analysis of both pressure and noise signals, accurate identification of the type of external leak is achieved, and the reliability of leak source location is improved. It effectively distinguishes between overt and minor external leaks, avoiding misjudgments caused by similar pressure attenuation amplitudes. Simultaneously, noise characteristic analysis provides auxiliary evidence for leak source location, significantly improving the accuracy and operability of airtightness testing.

[0071] In some embodiments, before generating the corresponding airtightness test results based on the attenuation magnitude of pressure information and the pump body type of the diaphragm pump under test, the method further includes: constructing type feature information characterizing the pump body type of the diaphragm pump under test; inputting the type feature information into a preset pressure attenuation value prediction model to dynamically determine the corresponding pressure attenuation threshold based on the pump body type of the diaphragm pump under test. It can be understood that the type feature information refers to a set of quantitative parameters used to distinguish the differences in different pump body structures. Specifically, it can be implemented using a combination of parameters such as pump body material code, number of diaphragm layers, and inlet / outlet diameter ratio. These parameters, after normalization, form a multi-dimensional feature vector used to characterize the influence of pump body structure on pressure attenuation characteristics.

[0072] The pressure decay prediction model is obtained by training a pre-defined support vector machine network based on training feature information. In essence, the pressure decay prediction model is a dynamic threshold calculation tool built through machine learning. Specifically, it can use a support vector machine network as its basic architecture, and input pressure decay curves and leakage annotation information corresponding to different pump types from historical detection data as training feature information. This allows the model to establish a mapping relationship between pump type and allowable pressure decay range, thereby replacing the traditional fixed threshold judgment method.

[0073] Before conducting airtightness testing, the structural parameters of the diaphragm pump under test are automatically obtained by scanning its model code. These parameters are then converted into standardized feature vectors as type feature information. This feature vector is input into a pre-trained pressure decay prediction model, which outputs a corresponding dynamic pressure decay threshold based on the pump's structural characteristics. For example, for a multi-layer diaphragm pump, the model may output a higher allowable decay threshold to accommodate its inherent elastic deformation characteristics; for metal pumps, the model outputs a lower threshold to match its rigid structural characteristics. This dynamic threshold determination method avoids the misjudgment problems caused by traditional fixed thresholds. Therefore, by establishing a dynamic correlation between pump type and pressure decay threshold, interference from structural differences can be eliminated, improving accuracy and effectively solving the misjudgment problem caused by traditional testing methods ignoring pump structural differences. The dynamic adaptation of the pressure decay threshold through a machine learning model ensures that the airtightness test results accurately reflect the actual leakage state rather than structural deformation interference, while avoiding the tedious manual threshold adjustment, significantly improving the automation level and batch testing efficiency of the testing process.

[0074] See Figure 3 In one embodiment, after the control pressure generating module applies positive pressure to the inlet end of the diaphragm pump under test, the method for generating airtightness test results includes, but is not limited to, steps S301 to S307.

[0075] Step S301: Obtain the first pressure attenuation value.

[0076] The first pressure decay value is the pressure at the inlet of the diaphragm pump under test, reached after a first preset time interval following the application of positive pressure. In essence, the first pressure decay value refers to the pressure drop at a specific point in time after the application of positive pressure. Specifically, it can be achieved by using a pressure sensor to collect the inlet pressure value at the end of the first preset time interval and comparing it with the initial pressure value to calculate the difference. This parameter is used to quantify the degree of external leakage, and its time window setting avoids the influence of transient interference on the detection results.

[0077] Step S302: Determine whether the first pressure attenuation value exceeds the first pressure attenuation threshold.

[0078] If the time limit is not exceeded, proceed to step S303; if the time limit is exceeded, proceed to step S304.

[0079] The first pressure attenuation threshold is generated by a pressure attenuation value prediction model. It can be understood that the first pressure attenuation threshold refers to a dynamically adjusted judgment standard based on the pump type. Specifically, it can be generated by training a support vector machine model on pressure attenuation data for different pump types, thus solving the problem of poor adaptability of traditional fixed thresholds to different pump types.

[0080] Step S303: Generate the airtightness test result indicating that the external leakage detection at the inlet has passed.

[0081] Step S304: Obtain the noise value of the preset frequency band obtained by collecting noise in the preset frequency band.

[0082] It is understandable that the preset frequency band noise value refers to the acoustic signal intensity within a specific frequency range. Specifically, it can be achieved by using a bandpass filter in conjunction with a microphone array to collect the sound pressure level of the target frequency band, which is used to distinguish between explicit external leakage and background noise.

[0083] Step S305: Determine whether the decibel value of the preset frequency band noise value reaches the preset decibel threshold.

[0084] If the condition is met, proceed to step S306; otherwise, proceed to step S307.

[0085] Step S306: Generate the airtightness test result indicating that there is a visible external leak at the inlet end.

[0086] Step S307: Generate corresponding airtightness test results based on the pressure fluctuation information at the inlet of the diaphragm pump under test within the first preset time period.

[0087] It can be understood that pressure fluctuation information refers to the dynamic characteristics of pressure changes over time. Specifically, it can be achieved by extracting high-frequency components through wavelet packet decomposition, which is used to detect pressure disturbances caused by micro-leakage.

[0088] After the control pressure generation module applies positive pressure to the inlet of the diaphragm pump under test, it continuously monitors the inlet until the end of a first preset time period, obtaining the first pressure attenuation value. For example, the first preset time period can be 60 seconds. The pressure detected at the inlet of the diaphragm pump after applying positive pressure and waiting 60 seconds is the first pressure attenuation value. When the first pressure attenuation value does not exceed the first pressure attenuation threshold, the external leakage detection is directly determined to be qualified, and an airtightness test result indicating that the external leakage detection at the inlet has passed is generated. When the first pressure attenuation value exceeds the first pressure attenuation threshold, noise detection is initiated. The presence of obvious leakage sound is determined by analyzing the noise intensity of a preset frequency band. When the decibel value of the noise in the preset frequency band reaches the preset decibel threshold, a visible external leakage is determined, and an airtightness test result indicating that there is a visible external leakage at the inlet is generated. When the decibel value of the preset frequency band noise does not reach the preset decibel threshold, the pressure fluctuation characteristics of both the inlet and outlet ends of the tested diaphragm pump are further analyzed. High-frequency components are extracted using wavelet packet decomposition to determine the presence of micro-leakage, generating corresponding airtightness test results. This multi-level detection mechanism sequentially eliminates environmental interference and gradually narrows the fault determination range, ensuring both detection efficiency and accuracy. Thus, the three-level verification mechanism—dynamic prediction of pressure attenuation threshold, noise frequency band screening, and pressure fluctuation characteristic analysis—effectively improves detection accuracy. Simultaneously, the introduction of frequency band noise detection can quickly locate obvious leak sources, while wavelet packet decomposition technology can capture micro-leakage signals that are difficult to identify using traditional methods, achieving accurate differentiation of external leak types. Obvious leaks are quickly determined through noise detection, while micro-leakages are identified through pressure fluctuation characteristics, solving the problems of high false positive rates and missed micro-leakage detection in traditional detection methods. The multi-level detection process, while ensuring detection efficiency, raises the leak detection sensitivity to the micro-leakage level, while effectively eliminating environmental noise interference through frequency band screening.

[0089] In some embodiments, generating a corresponding airtightness test result based on the pressure fluctuation information at the inlet of the diaphragm pump under test within a first preset time period includes: performing wavelet packet decomposition on the pressure fluctuation information to obtain pressure decomposition information; extracting pressure fluctuation features in a preset frequency band from the pressure decomposition information; determining whether the pressure fluctuation features meet preset feature fluctuation conditions; if they meet, generating an airtightness test result indicating that the inlet micro-leakage detection has passed; if they do not meet, generating an airtightness test result indicating that the inlet has micro-leakage.

[0090] Wavelet packet decomposition refers to the process of decomposing pressure fluctuation signals into sub-signals of different frequency bands using multi-scale time-frequency analysis. Specifically, it can be implemented using the Daubechies wavelet basis function, which obtains the energy distribution characteristics of different frequency bands by decomposing the signal layer by layer, and is used to capture high-frequency weak leakage signals in pressure fluctuations.

[0091] Pressure decomposition information refers to the energy distribution data of each frequency band sub-signal obtained after wavelet packet decomposition. Specifically, it can be achieved by calculating the root mean square value or energy proportion of each sub-frequency band, which is used to quantify the pressure fluctuation intensity of different frequency bands.

[0092] The pressure fluctuation characteristics of the preset frequency band refer to the signal characteristics within a specific frequency range related to micro-external leakage, such as the energy amplitude of 1kHz-5kHz, corresponding to the turbulent noise signal generated by the micro-leakage. The characteristic fluctuation condition refers to the quantification threshold for determining the existence of micro-external leakage; for example, it could be whether the ratio of the high-frequency energy amplitude to the reference value exceeds a set threshold. This condition is determined through statistical analysis of experimental data. When the decibel value of the noise in the preset frequency band does not reach the preset decibel threshold, the control module acquires the pressure fluctuation information continuously collected by the pressure detection module at the inlet of the tested diaphragm pump. Then, wavelet packet decomposition is performed on the pressure fluctuation information, decomposing it into multiple sub-signals of different frequency bands, i.e., pressure decomposition information. For example, using three-level wavelet packet decomposition can divide the signal into eight frequency bands, where the preset frequency band can be selected as the high-frequency sub-band after the third level of decomposition. The energy amplitude in the pressure decomposition information is extracted as the pressure fluctuation characteristic and compared with the preset threshold range. If the pressure fluctuation characteristics meet preset characteristic fluctuation conditions, such as the characteristic value of the pressure fluctuation characteristics being within a preset characteristic threshold range, then the pressure fluctuation is determined to be caused by environmental noise or inherent system vibration, and a conclusion of passing the micro-external leak detection is generated, resulting in an airtightness test result indicating that the inlet end micro-external leak detection has passed. If it exceeds the threshold range, then a micro-external leak is determined to exist, resulting in an airtightness test result indicating that the inlet end has a micro-external leak. Thus, by extracting pressure fluctuation characteristics in a specific frequency band through wavelet packet decomposition, high-frequency leakage signals and low-frequency system noise can be effectively separated. For example, when there are tiny cracks, the leaking airflow will generate high-frequency turbulent noise, which conventional pressure attenuation detection may not be able to capture.

[0093] See Figure 4 In one embodiment, after the control pressure generating module applies negative pressure to the inlet end of the diaphragm pump under test, the method for generating airtightness test results includes, but is not limited to, steps S401 to S404.

[0094] Step S401: Obtain the second pressure attenuation value.

[0095] The second pressure attenuation value is the root mean square (RMS) of the pressure at the inlet of the diaphragm pump under test within a second preset time period after applying negative pressure. In essence, the second pressure attenuation value is a statistical measure of the pressure change at the inlet after applying negative pressure. Specifically, it can be achieved by calculating the RMS value after collecting pressure data using a pressure sensor, and is used to quantify the pressure fluctuation amplitude.

[0096] Step S402: Determine whether the second pressure attenuation value exceeds the second pressure attenuation threshold.

[0097] If the time limit is not exceeded, proceed to step S403; if the time limit is exceeded, proceed to step S404.

[0098] The second pressure attenuation threshold is generated by the pressure attenuation value prediction model. It can be understood that the second pressure attenuation threshold refers to a dynamically adjusted judgment criterion, which can be generated by the pressure attenuation value prediction model based on the pump type. For example, a support vector machine model can be used to train historical data of different types of diaphragm pumps and then output the threshold.

[0099] Step S403: Generate the airtightness test result indicating that the internal leakage detection at the inlet has passed.

[0100] Step S404: Use the time difference algorithm to locate the leakage source. When the leakage source is the inlet end of the diaphragm pump under test, generate an airtightness test result indicating that there is an internal leakage at the inlet end.

[0101] It is understandable that the time difference algorithm refers to a method for locating the leakage source based on the difference in pressure wave propagation time. Specifically, it can be achieved by comparing the pressure fluctuation time difference between the inlet and outlet ends, for example, by using cross-correlation analysis to determine the time difference.

[0102] After the control pressure generation module applies negative pressure to the inlet of the diaphragm pump under test, the control module continuously collects the pressure information at the inlet of the diaphragm pump under test through the pressure detection module, and calculates the root mean square value of the pressure within a second preset time period as the second pressure decay value, for example, the second preset time period is 10 seconds. The control module calls the pressure decay value prediction model to generate the corresponding second pressure decay threshold according to the type characteristics of the diaphragm pump under test. If the second pressure decay value does not exceed the second pressure decay threshold, the internal leakage detection is determined to be passed, and an airtightness detection result indicating that the internal leakage detection at the inlet has passed is generated. If the second pressure decay value exceeds the second pressure decay threshold, the leakage source location process is initiated. The time difference algorithm is used to analyze the pressure fluctuation time difference between the inlet and outlet of the diaphragm pump under test. When the time difference matches the leakage characteristics at the inlet, it is determined that there is an internal leakage at the inlet, and an airtightness detection result indicating that there is an internal leakage at the inlet is generated. Therefore, the detection accuracy is improved by using a dynamic threshold generation model, and the leak source is accurately located by combining it with a time difference algorithm. This solves the problems of high false positive rate and inability to distinguish the location of leaks in traditional methods. It can automatically generate appropriate detection thresholds for different models of diaphragm pumps, avoiding false positives caused by differences in pump structure. At the same time, the leak source is accurately located by pressure fluctuation time difference analysis, effectively distinguishing internal leakage at the inlet end from other potential leakage situations, and improving the reliability of detection results.

[0103] See Figure 5 In one embodiment, after the control pressure generating module applies positive pressure to the outlet end of the diaphragm pump under test, the method for generating airtightness test results includes, but is not limited to, steps S501 to S504.

[0104] Step S501: Obtain the third pressure attenuation value.

[0105] The third pressure attenuation value is the root mean square (RMS) of the pressure at the inlet of the diaphragm pump under test within a third preset time period after positive pressure is applied to the outlet of the diaphragm pump under test. In other words, the third pressure attenuation value is a quantitative index of pressure fluctuation calculated by continuously collecting pressure data at the inlet of the diaphragm pump under test through a pressure detection module and then performing the RMS calculation. Specifically, it can be implemented using a pressure sensor combined with a data processor, and is used to characterize the pressure stability at the inlet after positive pressure is applied to the outlet.

[0106] Step S502: Determine whether the third pressure attenuation value exceeds the third pressure attenuation threshold.

[0107] If the time limit is not exceeded, proceed to step S503; if the time limit is exceeded, proceed to step S504.

[0108] The third pressure attenuation threshold is generated by the pressure attenuation value prediction model. It can be understood that the third pressure attenuation threshold refers to a dynamically adjusted judgment criterion, which can be generated by the pressure attenuation value prediction model based on the pump type. For example, a support vector machine model can be used to train historical data of different types of diaphragm pumps and then output the threshold.

[0109] Step S503: Generate the airtightness test result indicating that the internal leakage detection at the outlet end has passed.

[0110] Step S504: Use the time difference algorithm to locate the leakage source. When the leakage source is the outlet end of the diaphragm pump under test, generate an airtightness test result indicating that there is internal leakage at the outlet end.

[0111] After the control module applies positive pressure to the outlet of the diaphragm pump under test through the pressure generation module, it continuously collects the pressure information at the outlet of the diaphragm pump under test through the pressure detection module. It calculates the root mean square (RMS) value of the pressure within a third preset time period (e.g., 10 seconds) as the third pressure attenuation value. The control module then calls the pressure attenuation value prediction model to generate a corresponding third pressure attenuation threshold based on the type characteristics of the diaphragm pump under test. If the third pressure attenuation value does not exceed the third pressure attenuation threshold, the internal leakage detection is deemed successful, and an airtightness test result indicating successful internal leakage at the outlet is generated. If the third pressure attenuation value exceeds the third pressure attenuation threshold, the leak source location process is initiated. A time difference algorithm is used to analyze the pressure fluctuation time difference between the inlet and outlet of the diaphragm pump under test. When the time difference matches the leakage characteristics at the outlet, an internal leakage is determined at the outlet, and an airtightness test result indicating internal leakage at the outlet is generated. Thus, by calculating the root mean square pressure, precise quantification of pressure fluctuations is achieved. Combined with a machine learning model to dynamically adjust the judgment criteria, it can adapt to the testing needs of different types of diaphragm pumps. The time difference algorithm replaces manual sound-based leak detection, enabling automatic location of the leak source. It effectively solves the problems of high misjudgment rate and difficulty in locating the leak source in the internal leak detection at the outlet end. The root mean square pressure calculation eliminates the influence of instantaneous interference on the detection results, and the pressure decay value prediction model improves the detection adaptability of different pump types. The time difference algorithm enables precise location of the leak, making the detection process fully automated.

[0112] In some embodiments, a time difference algorithm is used to locate the leak source, including: determining the time difference of pressure information fluctuations between the inlet and outlet ends of the diaphragm pump under test; and locating the leak source based on the time difference of pressure information fluctuations. It can be understood that the time difference of pressure information fluctuations refers to the difference in the time interval between the inlet and outlet ends when a leak occurs, and can be specifically implemented using a high-precision pressure sensor combined with a timer module, calculating the time difference by capturing the starting point of the pressure change.

[0113] When an internal leak occurs in the diaphragm pump under test, the pressure fluctuations generated at the leak point will be transmitted to the inlet and outlet ends of the pump at different times. For example, if the leak source is located near the inlet end of the pump, the pressure fluctuations will first be detected by the pressure sensor at the inlet end, and then propagate to the outlet end. The leak direction can then be determined by calculating the time difference between the pressure signals at both ends. Furthermore, the pressure sensor inputs the real-time collected pressure data to the control module, which uses a cross-correlation function to determine the maximum offset of the time difference, thereby locating the leak source. A positive time difference indicates that the leak source is closer to the inlet end, while a negative time difference indicates it is closer to the outlet end. Thus, the leak direction can be automatically identified directly through an algorithm, significantly shortening the fault diagnosis time and solving the problem of not being able to locate the leak source in existing technologies. This achieves automated judgment of the diaphragm pump leak direction, making it particularly suitable for quickly identifying defect locations in mass production scenarios and avoiding efficiency losses caused by manual inspection. Furthermore, this solution can distinguish between the leak types at the inlet and outlet ends, providing clear guidance for subsequent maintenance and enhancing the practical value of airtightness testing.

[0114] In summary, the diaphragm pump airtightness testing system provided in this application achieves adaptive adjustment of testing standards through the dynamic correlation between pump type characteristics, pressure attenuation amplitude, and airtightness testing results. Unlike fixed testing devices, this system has multi-mode testing capabilities for positive and negative pressure, and can simultaneously complete external and internal leakage detection, realizing fully automated operation of diaphragm pump airtightness testing, eliminating efficiency bottlenecks caused by manual intervention. The dynamic correlation mechanism between pump type characteristics, pressure attenuation amplitude, and airtightness testing results effectively solves the compatibility problem of multi-model mixed production lines, improving the testing efficiency and accuracy of diaphragm pump airtightness testing.

[0115] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0116] The preferred embodiments of the present application have been described above with reference to the accompanying drawings, but this does not limit the scope of the claims of the present application. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and substance of the embodiments of the present application shall be within the scope of the claims of the present application.

Claims

1. A diaphragm pump airtightness testing system, characterized in that, include: The pressure generating module, connected to the inlet and outlet of the diaphragm pump under test, is configured to apply positive or negative pressure to the inlet or outlet of the diaphragm pump under test. The pressure detection module is connected to the inlet and outlet of the diaphragm pump under test and is configured to detect the pressure information at the inlet or outlet of the diaphragm pump under test. The control module is configured to control the pressure generating module to apply positive or negative pressure to the inlet end of the diaphragm pump under test or to apply positive pressure to the outlet end of the diaphragm pump under test, and to generate corresponding air tightness test results based on the attenuation magnitude of the pressure information and the pump body type of the diaphragm pump under test. Before generating the corresponding airtightness test result based on the attenuation magnitude of the pressure information and the pump body type of the diaphragm pump under test, the method further includes: Construct type feature information that characterizes the pump body type of the tested diaphragm pump; The type feature information is input into a preset pressure decay value prediction model to dynamically determine the corresponding pressure decay threshold based on the pump body type of the diaphragm pump under test; the pressure decay value prediction model is obtained by training a preset support vector machine network based on training feature information. The diaphragm pump air tightness testing system also includes a noise detection device, configured to collect noise in a preset frequency band when an external leak is detected at the inlet end of the diaphragm pump under test.

2. The diaphragm pump airtightness testing system according to claim 1, characterized in that, The pressure generating module includes a vacuum generator and a gas source, forming a first gas path, a second gas path and a third gas path; In the first gas path, the gas source and the vacuum generator are connected by a pipeline, and the vacuum generator is connected to the inlet end of the diaphragm pump under test by a pipeline. In the second gas path, the gas source is connected to the inlet end of the diaphragm pump under test through a pipeline; In the third gas path, the gas source is connected to the outlet end of the diaphragm pump under test via a pipeline; The first air path, the second air path, and the third air path are each equipped with at least one pressure regulating valve and at least one switching valve.

3. The diaphragm pump airtightness testing system according to claim 1, characterized in that, The pressure detection module includes a first pressure detection device, a flow meter, a second pressure detection device, and a water storage tank, forming a first liquid path and a second liquid path; In the first liquid path, the outlet end of the diaphragm pump under test, the first pressure detection device, the flow meter and the water storage tank are connected by a pipeline; In the second liquid path, the inlet end of the diaphragm pump under test, the second pressure detection device, and the water storage tank are connected by a pipeline; The first liquid path and the second liquid path are each equipped with at least one switching valve.

4. The diaphragm pump airtightness testing system according to claim 1, characterized in that, After the pressure generating module applies positive pressure to the inlet of the diaphragm pump under test, the corresponding airtightness test result is generated based on the attenuation magnitude of the pressure information and the pump body type of the diaphragm pump under test, including: Obtain a first pressure decay value; the first pressure decay value is the pressure value at the inlet of the diaphragm pump under test when a first preset time has elapsed after applying positive pressure to the inlet of the diaphragm pump under test. Determine whether the first pressure attenuation value exceeds a first pressure attenuation threshold; the first pressure attenuation threshold is generated by the pressure attenuation value prediction model. If the limit is not exceeded, an airtightness test result indicating that the inlet leakage detection has passed will be generated. If the noise level exceeds the preset frequency band noise value, the preset frequency band noise value is obtained by collecting noise from the preset frequency band. Determine whether the decibel value of the preset frequency band noise reaches the preset decibel threshold; If this is achieved, a leak test result will be generated indicating that there is a visible external leak at the inlet end; If the pressure fluctuation information at the inlet of the diaphragm pump under test is not reached, a corresponding airtightness test result is generated based on the pressure fluctuation information at the inlet of the diaphragm pump under test within the first preset time period.

5. The diaphragm pump airtightness testing system according to claim 4, characterized in that, The generation of corresponding airtightness test results based on the pressure fluctuation information at the inlet of the diaphragm pump under test within the first preset time period includes: Wavelet packet decomposition is performed on the pressure fluctuation information to obtain pressure decomposition information; Extract pressure fluctuation characteristics of a preset frequency band from the pressure decomposition information; Determine whether the pressure fluctuation characteristics meet the preset characteristic fluctuation conditions; If the conditions are met, an airtightness test result indicating that the inlet end micro-leakage detection has passed will be generated. If it does not meet the requirements, an airtightness test result will be generated indicating a slight external leak at the inlet.

6. The diaphragm pump airtightness testing system according to claim 1, characterized in that, After the pressure generating module applies negative pressure to the inlet of the diaphragm pump under test, the corresponding airtightness test result is generated based on the attenuation magnitude of the pressure information and the pump body type of the diaphragm pump under test, including: Obtain a second pressure decay value; the second pressure decay value is the root mean square pressure at the inlet of the diaphragm pump under test within a second preset time after a negative pressure is applied to the inlet of the diaphragm pump under test. Determine whether the second pressure decay value exceeds the second pressure decay threshold; the second pressure decay threshold is generated by the pressure decay value prediction model. If the limit is not exceeded, an airtightness test result indicating that the inlet leakage detection has passed will be generated. If the time difference exceeds the limit, the leak source is located using a time difference algorithm. When the leak source is the inlet end of the diaphragm pump under test, an airtightness test result indicating internal leakage at the inlet end is generated.

7. The diaphragm pump airtightness testing system according to claim 1, characterized in that, After the pressure generating module applies positive pressure to the outlet end of the diaphragm pump under test, the corresponding airtightness test result is generated based on the attenuation magnitude of the pressure information and the pump body type of the diaphragm pump under test, including: Obtain the third pressure decay value; the third pressure decay value is the root mean square pressure at the inlet of the diaphragm pump under test within a third preset time after a positive pressure is applied to the outlet of the diaphragm pump under test. Determine whether the third pressure attenuation value exceeds the third pressure attenuation threshold; the third pressure attenuation threshold is generated by the pressure attenuation value prediction model. If the limit is not exceeded, an airtightness test result indicating that the internal leakage detection at the outlet end has passed will be generated. If the time difference exceeds the limit, the leak source is located using a time difference algorithm. When the leak source is the outlet end of the diaphragm pump under test, an airtightness test result indicating internal leakage at the outlet end is generated.

8. The diaphragm pump airtightness testing system according to claim 6 or 7, characterized in that, The method of using a time difference algorithm to locate the leakage source includes: Determine the time difference between the pressure fluctuations at the inlet and outlet of the diaphragm pump under test; The leak source is located based on the time difference of the pressure information fluctuation.

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