Positive and negative pressure general filter test equipment and test method

Abstract

The invention relates to the field of filters, and discloses positive and negative pressure general filter testing equipment and a testing method, and the equipment comprises the following modules: a pressure control module which is equipped with a positive and negative pressure bidirectional pressure pump, a positive and negative pressure collector and a master controller; the flow adjusting module comprises an intelligent flow adjusting valve and a positive and negative pressure collector; the test cavity module adopts a sealed pressure-resistant structure, and an adjustable airflow distribution device is arranged in the test cavity module; the data acquisition and analysis module is used for acquiring pressure, flow, filtering efficiency and resistance data in real time and generating a test report; all the modules are connected through standardized interfaces and can be combined and expanded. By adopting the positive and negative pressure integrated test process, the operation complexity is reduced, the operation error probability is reduced, the test preparation time is shortened, meanwhile, the idle and repeated operation time of equipment is shortened through the coherent test process, seamless transition from positive pressure test to negative pressure test and complex working condition simulation test can also be efficiently completed, the test quantity in unit time is increased, and the test efficiency is improved. The rapid detection requirement is met.

Description

Technical Field

[0001] The present invention relates to the field of filters, in particular to a positive and negative pressure universal filter testing device and a testing method. Background Art

[0002] In modern industrial production, scientific research experiments and many other fields that have requirements for air quality and fluid purity, filters play a vital role. They can effectively remove impurities, particles and other pollutants in the air or fluid to ensure the normal operation of the system and product quality. With the continuous development and progress of related industries, the demand for filter performance testing is growing and becoming more and more stringent, which also drives the continuous updating and iteration of filter testing technology and equipment.

[0003] Related filter testing equipment generally has the problem of single function in positive pressure and negative pressure testing scenarios. Most equipment can only meet the testing requirements of positive pressure conditions or negative pressure conditions in a targeted manner, and cannot achieve universal testing of positive and negative pressure conditions. When the actual application scenario requires a comprehensive evaluation of the performance of the same filter under two different pressure environments, positive pressure and negative pressure, it is necessary to use positive pressure testing equipment and negative pressure testing equipment respectively. This undoubtedly greatly increases the time cost of testing and reduces the test volume per unit time. Summary of the Invention

[0004] In response to the shortcomings of the existing technology, the present invention provides a universal positive and negative pressure filter testing equipment and testing method, which solves the problem of increased testing time cost and reduced test volume per unit time due to the single function of the relevant filter testing equipment in positive and negative pressure testing scenarios.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions: a positive and negative pressure universal filter testing equipment, characterized in that it includes an all-in-one machine, a filter body is provided on the outside of the all-in-one machine, the all-in-one machine is equipped with positive and negative pressure gauges, the all-in-one machine is provided with an air intake interface, the all-in-one machine is equipped with an air storage tank assembly, the air storage tank assembly is equipped with a bidirectional pressure pump, the air storage tank assembly is equipped with an air intake boost valve assembly, the all-in-one machine is equipped with an intelligent flow regulating valve, a positive and negative pressure collector, a proportional valve controller, a main controller, a vacuum generator air intake adjustment, a vacuum generator, a vacuum control valve, a proportional valve, a network switch, a communicator, an air flow distribution device and a control valve, the vacuum generator is electrically connected to the vacuum control valve, the main controller is electrically connected to the vacuum control valve, the communicator and the control valve, the communicator is electrically connected to the positive and negative pressure collector, the proportional valve controller and the network switch, the positive and negative pressure collector is electrically connected to the positive and negative pressure gauges, and the network switch is electrically connected to the all-in-one machine.

[0006] Through the above technical solution, the pressurized gas is input into the proportional valve through the intake boost valve assembly, and the proportional valve adjusts the pressure according to the pressure parameters set by the main controller; the pressure-regulated gas is evenly distributed to the five-way positive and negative pressure gauges, and respectively injected into the filter body to be tested in the five-station test chamber. The airflow treated by the filter is independently adjusted by the five-way independent control valves to adjust the output flow, and finally the airflow is evenly distributed and discharged through the airflow distribution device, and the vacuum generator intake adjustment controls the gas flow input to the vacuum generator. The vacuum generator generates a target negative pressure environment under the coordinated action of the vacuum control valve; the negative pressure acts on the test chamber, participates in the negative pressure working condition performance test of the filter body, and seamlessly transitions from positive pressure test to negative pressure test. Complex working condition simulation test can also be completed efficiently, thereby increasing the test volume per unit time and meeting the needs of rapid detection.

[0007] Preferably, the following modules are included:

[0008] Pressure control module: includes a positive and negative pressure bidirectional pressure pump, a positive and negative pressure collector, and a master controller; the bidirectional pressure pump can output positive or negative pressure airflow, the positive and negative pressure collector monitors the pressure of the integrated machine in real time and feeds back to the master controller, which automatically adjusts the output of the bidirectional pressure pump based on the feedback data;

[0009] Flow regulation module: includes an intelligent flow regulation valve and a positive and negative pressure collector. The intelligent flow regulation valve automatically adjusts the flow according to the filter body type and test conditions. The positive and negative pressure collector monitors the flow data in real time and transmits it to the data acquisition and analysis module.

[0010] Test chamber module: adopts a sealed pressure-resistant structure with an adjustable airflow distribution device inside, used to install the filter body to be tested and withstand pressure changes under positive and negative pressure conditions;

[0011] Data acquisition and analysis module: includes a communicator and a network switch, collects pressure, flow, filtration efficiency and resistance data in real time, and generates a test report;

[0012] Each module is connected through a standardized interface and can be combined and expanded.

[0013] Preferably, the intelligent flow regulating valve is directly connected to the main controller and automatically adapts the flow according to the preset filter body specification parameters; the positive and negative pressure collector uses CRC16 check code to transmit data to the data acquisition and analysis module.

[0014] Preferably, the airflow distribution device of the test chamber module is a porous adjustable guide structure, which supports uniform airflow distribution under alternating positive and negative pressure conditions; the test chamber sealing structure adopts a quick installation interface to avoid leakage errors caused by repeated installation.

[0015] Preferably, the data acquisition and analysis module supports six test mode data analyses:

[0016] Specify pressure mode: analyze pressure value, holding time and qualification judgment;

[0017] Step pressure mode: analyze the number of steps, number of cycles and single cycle / multi-cycle judgment;

[0018] Start-stop shock mode: analyze shock cycle times and interruption and continuation data;

[0019] Fatigue cycle mode: analysis time interval and test duration;

[0020] Factory test mode: Analyzes the response characteristics of the air supply pressure step signal, including the linearity deviation between the proportional valve input voltage and output pressure, and the step response time of the positive and negative pressure collectors;

[0021] Self-test mode: Analyzes the internal gas path sealing data of the equipment, including the internal leakage rate of the equipment and the adjustment accuracy fluctuation range of the proportional valve at a pressure of 0.5MPa.

[0022] Preferably, a testing method for a positive and negative pressure universal filter testing device comprises the following steps:

[0023] S1: Install the filter body to be tested in the test chamber to ensure sealing;

[0024] S2: Set test parameters and start device self-test;

[0025] S3: Perform stress testing, including any of the following modes;

[0026] Specified pressure mode: adjust the step air pressure to the target value through the proportional valve;

[0027] Step pressure mode: adjust the pressure step by step in ≤5 steps;

[0028] Start-stop impact mode: cyclic execution of the change from "0→target pressure→maintaining pressure→0";

[0029] Fatigue cycle mode: periodically start and stop the pressure at fixed time intervals;

[0030] Factory test mode: detect the response characteristics of the air supply pressure step signal and verify the dynamic adjustment performance of the proportional valve;

[0031] Self-test mode: disconnect the filter body and directly connect the air path to test the internal sealing and pressure holding capacity of the equipment;

[0032] S4: Real-time monitoring of pressure and flow, collection of filtration efficiency and resistance data;

[0033] S5: If it is a complex working condition test, perform the positive and negative pressure alternation procedure and record the performance changes;

[0034] S6: The data acquisition and analysis module generates a test report and outputs the judgment results.

[0035] Preferably, when the specified pressure mode is selected in S3, the detection pressure value and fluctuation range are set; a step pressure signal is output through the proportional valve; it is determined whether the pressure drop exceeds the limit during the pressure holding time, and the qualified / unqualified result and the effective pressure holding time are output.

[0036] Preferably, when the step pressure mode is selected in S3, the number of steps is set to ≤ 5, the pressure value of each step and the holding time; a single cycle or multi-cycle mode is executed; when a step test fails, the current cycle number is paused and recorded, and the accumulation is continued after manual intervention.

[0037] Preferably, when the start-stop impact mode is selected in S3, the target pressure value and the number of cycles are set; the "0→target pressure→maintaining pressure→0" process is executed in a single cycle; the current number is recorded when the cycle is interrupted, and the accumulation is continued after manual intervention; when the fatigue cycle mode is selected in S3, the pressure start-stop time interval and the total test time are set; the pressure increase-maintaining-pressure reduction process is executed periodically; the pressure decay curve is recorded in real time and the sealing failure point is determined.

[0038] Preferably, when the factory test mode is selected in S3, a 1V to 10V step voltage signal is input to the proportional valve to verify whether the output pressure matches the linear correspondence of 100kPa to 2MPa, and the response time of the positive and negative pressure collectors from the initial supply pressure value to the detection pressure change is recorded. The fluctuation of the supply pressure step signal curve is analyzed by the upper computer software, and a linear deviation report is output; when the self-test mode is selected in S3, the filter body is disconnected, and the test chamber air path is directly connected to the atmosphere. A pressure of 0.5MPa is applied inside the equipment and the pressure is maintained for 10 seconds. If the pressure drop is greater than 0.5kPa, it is determined that the air path leakage is abnormal, and the fluctuation range of the proportional valve adjustment accuracy is monitored at the same time.

[0039] The present invention provides a positive and negative pressure universal filter testing device and testing method. It has the following beneficial effects:

[0040] 1. The present invention adopts an integrated positive and negative pressure testing process, which eliminates the need for testers to frequently switch equipment and reinstall filters, and operators do not need to master two sets of operating specifications, thereby reducing operational complexity, reducing the probability of operational errors, and shortening test preparation time. At the same time, the coherent testing process reduces equipment idleness and repeated operation time, and seamlessly transitions from positive pressure testing to negative pressure testing. Complex working condition simulation tests can also be completed efficiently, thereby increasing the test volume per unit time and meeting the needs of rapid detection.

[0041] 2. The present invention avoids human errors by reducing equipment switching and repeated installation of filters. At the same time, intelligent flow regulation and monitoring ensure stable airflow during the test. High-precision positive and negative pressure bidirectional pressure control ensures accurate pressure conditions, providing reliable test conditions for filter performance evaluation. Through positive and negative pressure testing and complex working condition simulation, the performance data of the filter under various pressure environments can be obtained. Combined with real-time data collection and analysis, accurate and comprehensive data support is provided for filter research and development and production.

[0042] 3. The present invention uses modular integrated design to enable one set of equipment to meet the needs of positive and negative pressure testing. Enterprises do not need to purchase positive and negative pressure testing equipment separately, reducing equipment procurement capital investment. The modular structure of the equipment facilitates maintenance, and the maintenance and management of one set of equipment is simpler than that of two sets of equipment, reducing the consumption of manpower and material resources, and reducing equipment maintenance costs and time costs.

[0043] 4. The present invention adapts to the testing requirements of filters of different types and specifications by adjusting the modular structure of the configuration; the complex working condition simulation function enables the equipment to simulate the complex pressure environment in actual use of the filter, providing an effective testing means for the development of new filters, helping testers to efficiently test and optimize filter performance, accelerate the development process of new filters, and improve the quality and performance of filter products. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 A three-dimensional diagram of a positive and negative pressure universal filter testing device of the present invention;

[0045] Figure 2 This is a system framework diagram of a positive and negative pressure universal filter testing device of the present invention;

[0046] Figure 3 A schematic diagram of pressure changes during a specified pressure test of a testing method for a positive and negative pressure universal filter testing device according to the present invention;

[0047] Figure 4 A schematic diagram of pressure changes in a step pressure test of a testing method for a positive and negative pressure universal filter testing device of the present invention;

[0048] Figure 5 A schematic diagram of pressure changes during a start-stop impact test of a positive and negative pressure universal filter testing device according to the present invention;

[0049] Figure 6 A schematic diagram of pressure changes during a fatigue cycle test of a testing method for a positive and negative pressure universal filter testing device according to the present invention;

[0050] Figure 7 A schematic diagram of factory test pressure changes in a test method for a positive and negative pressure universal filter test device of the present invention;

[0051] Figure 8 A schematic diagram of test pressure changes in a self-test mode of a test method for a positive and negative pressure universal filter test device according to the present invention;

[0052] Figure 9 A schematic diagram of a testing process of a testing method for a positive and negative pressure universal filter testing device of the present invention;

[0053] Figure 10 A schematic diagram of data collection and analysis of a testing method for a positive and negative pressure universal filter testing device according to the present invention;

[0054] Figure 11 A schematic diagram of an air circuit diagram of a testing method for a positive and negative pressure universal filter testing device of the present invention;

[0055] Figure 12 This is a partial structural diagram of a positive and negative pressure collector of a testing method for a positive and negative pressure universal filter testing device of the present invention.

[0056] Among them, 1. Bidirectional pressure pump; 2. Filter body; 3. Intelligent flow control valve; 4. Positive and negative pressure collector; 5. Proportional valve controller; 6. Main controller; 7. Vacuum generator air intake adjustment; 8. Vacuum generator; 9. Vacuum control valve; 10. Proportional valve; 11. Network switch; 12. Communicator; 13. Air flow distribution device; 14. Control valve; 15. Air intake interface; 16. Positive and negative pressure gauges; 17. All-in-one machine; 18. Air storage tank assembly; 19. Intake boost valve assembly. DETAILED DESCRIPTION

[0057] The following will clearly and completely describe the technical solution of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0058] Please see the attached Figure 1 , Attachment Figure 10 , Attachment Figure 11 and attached Figure 12The embodiment of the present invention provides a positive and negative pressure universal filter testing device, including an all-in-one machine 17, a filter body 2 is provided on the outside of the all-in-one machine 17, a positive and negative pressure gauge 16 is installed on the all-in-one machine 17, an air inlet interface 15 is provided on the all-in-one machine 17, an air storage tank assembly 18 is installed on the air storage tank assembly 18, a bidirectional pressure pump 1 is installed on the air storage tank assembly 18, an air intake boost valve assembly 19 is installed on the air storage tank assembly 18, an intelligent flow regulating valve 3, a positive and negative pressure collector 4, a proportional valve controller 5, a master controller 6, a vacuum pump 7, a vacuum pump 8, a vacuum pump 9, a vacuum pump 10, a vacuum pump 11, a vacuum pump 12, a vacuum pump 13, a vacuum pump 14, a vacuum pump 15, a vacuum pump 16, a vacuum pump 17, a vacuum pump 18, a vacuum pump 1 ...8, a vacuum pump 19, a vacuum pump 18, a vacuum pump 19, a vacuum pump 11, a vacuum pump 12, a vacuum pump 13, a vacuum pump 14, a vacuum pump 15, a vacuum pump 16, a vacuum pump 18, a vacuum pump 18, a vacuum pump 18, a vacuum pump 18, a vacuum pump 18, a vacuum pump 19, a vacuum pump 18, a vacuum pump 18, a vacuum pump 18, a vacuum pump 18, a vacuum pump 18, a vacuum pump 18, a vacuum pump 18, a vacuum pump 18, a vacuum pump 18 Air generator air intake adjustment 7, vacuum generator 8, vacuum control valve 9, proportional valve 10, network switch 11, communicator 12, air flow distribution device 13 and control valve 14, the vacuum generator 8 is electrically connected to the vacuum control valve 9, the main controller 6 is electrically connected to the vacuum control valve 9, the communicator 12 and the control valve 14, the communicator 12 is electrically connected to the positive and negative pressure collector 4, the proportional valve controller 5 and the network switch 11, the positive and negative pressure collector 4 is electrically connected to the positive and negative pressure gauges 16, and the network switch 11 is electrically connected to the all-in-one machine 17.

[0059] Specifically, the gas from the external air supply source is introduced through the air inlet interface 15, flows through the air inlet pressure regulating valve assembly 19 to achieve initial pressure stabilization, and then enters the air storage tank assembly 18 for buffer storage after the initial flow is regulated by the intelligent flow regulating valve 3; the gas output by the air storage tank assembly 18 is pressurized by the bidirectional pressure pump 1, and then diverted to two independent test channels for positive pressure and negative pressure; in the positive pressure channel, the pressurized gas is delivered to the proportional valve 10 through the air inlet boosting valve assembly 19, and the proportional valve 10 adjusts the gas pressure according to the set parameters, and then evenly distributes the pressure-stabilized gas. Equipped with five-way positive and negative pressure gauges 16, and respectively input into the filter body 2 to be tested, which is installed in the five-station test chamber; the airflow processed by the filter body 2 is adjusted by the corresponding five-way independent control valves 14 to adjust its output flow, and finally discharged evenly from the test chamber through the airflow distribution device 13; in the negative pressure channel, the vacuum generator air inlet adjustment 7 controls the gas flow input to the vacuum generator 8. The vacuum generator 8 generates and maintains the required negative pressure environment under the coordinated action of the vacuum control valve 9. This negative pressure directly acts on the test chamber, participating in the negative pressure working condition test of the filter body 2;

[0060] During the positive and negative pressure dual-channel test, the intelligent flow regulating valve 3 continuously receives instructions from the main controller 6, dynamically adjusts the gas flow in the positive and negative pressure channels, and ensures that the test flow always meets the preset requirements; at the same time, the positive and negative pressure collector 4 collects pressure data from the five-way positive and negative pressure gauges 16 in real time, and these data are transmitted to the network switch 11 through the communicator 12; the main controller 6 sets and adjusts the pressure range required for the test through the proportional valve 10 on the one hand, and receives the real-time feedback data of the positive and negative pressure collectors 4 collected by the network switch 11 on the other hand, forming a closed-loop control circuit to achieve stable control of the test pressure; the airflow distribution device 13 set inside the test chamber guides The airflow passes through the filter body 2 of each workstation evenly to ensure the representativeness and accuracy of the test results; in order to simulate actual complex working conditions, the vacuum generator 8, vacuum control valve 9 and proportional valve 10 work together under the coordination of the main controller 6, and the pressure in the test chamber is switched between positive and negative pressure states stably and quickly through the switching of positive and negative dual channels; the main controller 6 integrates the real-time operating data from the intelligent flow control valve 3, positive and negative pressure collector 4 and proportional valve 10 through the network switch 11, executes the preset test logic sequence, and dynamically analyzes and generates the final test report based on the continuously collected flow and pressure parameters, thereby completing the qualified judgment of the product performance of the filter body 2.

[0061] See attached Figure 1 , Attachment Figure 2 , Attachment Figure 10 , Attachment Figure 11 and attached Figure 12 , including the following modules:

[0062] Pressure control module: includes a positive and negative pressure bidirectional pressure pump 1, a positive and negative pressure collector 4 and a main controller 6; the bidirectional pressure pump 1 can output positive or negative pressure airflow, the positive and negative pressure collector 4 monitors the pressure of the integrated machine 17 in real time and feeds back to the main controller 6, and the main controller 6 automatically adjusts the output of the bidirectional pressure pump 1 according to the feedback data;

[0063] Flow regulation module: includes an intelligent flow regulation valve 3 and a positive and negative pressure collector 4. The intelligent flow regulation valve 3 automatically adjusts the flow according to the type of the filter body 2 and the test conditions. The positive and negative pressure collector 4 monitors the flow data in real time and transmits it to the data acquisition and analysis module;

[0064] Test chamber module: adopts a sealed pressure-resistant structure, with an adjustable airflow distribution device 13 inside, used to install the filter body 2 to be tested and withstand pressure changes under positive and negative pressure conditions;

[0065] Data acquisition and analysis module: including a communicator 12 and a network switch 11, which collects pressure, flow, filtration efficiency and resistance data in real time and generates a test report;

[0066] Each module is connected through a standardized interface and can be combined and expanded.

[0067] Specifically, the pressure control module: the external air supply is input through the air inlet interface 15, and after the pressure is stabilized by the air inlet pressure regulating valve assembly 19, the initial flow is regulated by the intelligent flow regulating valve 3 and delivered to the air storage tank assembly 18; the gas in the air storage tank assembly 18 is pressurized by the bidirectional pressure pump 1 and then diverted to the positive and negative paths: in the positive pressure path, the gas enters the proportional valve 10 through the air inlet boosting valve assembly 19, and the proportional valve 10 adjusts the pressure according to the voltage instruction of the main controller 6, outputs to the five-way positive and negative pressure gauge 16, and passes into the filter body 2 of the five-station test chamber; in the negative pressure path, the vacuum generator air inlet adjustment 7 controls the gas input to the vacuum generator 8, and the vacuum control valve 9 cooperates to generate negative pressure and act on the test chamber. The positive and negative pressure collector 4 monitors the data of the five-way pressure gauge 16 in real time, and transmits it to the network switch 11 through the communicator 12. The main controller 6 dynamically adjusts the proportional valve 10 and the bidirectional pressure pump 1 based on the feedback data to achieve pressure control;

[0068] Flow regulation module: The intelligent flow regulating valve 3 receives instructions from the main controller 6 and synchronously adjusts the airflow rate of the positive pressure channel and the negative pressure channel; the positive and negative pressure collector 4 collects flow data in real time and feeds it back to the network switch 11 through the communicator 12. The main controller 6 dynamically adjusts the flow parameters based on the data to ensure that the test flow is consistent with the set value;

[0069] Test chamber module: The test chamber adopts a sealed and pressure-resistant structure, with an adjustable airflow distribution device 13 installed inside. After the five-station filter body 2 is fixed to the chamber, the airflow is distributed to each station through a proportional valve 10. After passing through the filter body 2, the output is adjusted by five independent control valves 14, and finally discharged evenly through the airflow distribution device 13. This device ensures uniform airflow distribution under positive and negative pressure conditions, and the chamber can withstand pressure fluctuations of -100kPa to 2MPa.

[0070] Data acquisition and analysis module: The communicator 12 collects pressure and flow data from the positive and negative pressure collector 4 through the 485 protocol, and aggregates the data to the main controller 6 through the network switch 11. The main controller 6 analyzes the data and links the host computer software for real-time analysis. That is, multiple sets of data for a single product are collected at set time intervals to generate a pressure fluctuation curve. The product qualification is determined by the stability of the curve, and the parameters collected by each module are integrated to automatically output positive pressure, negative pressure, and positive and negative pressure alternating test reports:

[0071] Modular integration: Each module is connected through a standardized electrical / pneumatic interface. The main controller 6 is connected to the proportional valve 10, the positive and negative pressure collector 4 and the five-way control valve 14 through the network switch 11 and the communicator 12 through the electrical interface; and the gas tank assembly 18, the two-way pressure pump 1, the proportional valve 10, etc. are connected in series through quick-connect pipelines to support rapid disassembly and expansion.

[0072] See attached Figure 12 The intelligent flow regulating valve 3 is directly connected to the main controller 6, and automatically adapts the flow according to the preset specification parameters of the filter body 2; the positive and negative pressure collector 4 uses CRC16 check code to transmit data to the data acquisition and analysis module.

[0073] Specifically, the intelligent flow control valve 3 is directly connected to the main controller 6 through an independent line and receives instructions issued by the main controller 6 in real time. The instructions are based on the type, specification parameters and test conditions of the filter body 2 preset by the host computer, and automatically calculate and output the corresponding flow setting value. The intelligent flow control valve 3 dynamically adjusts the valve opening according to the setting value to control the initial flow of gas entering the gas storage tank assembly 18, providing a flow reference for the subsequent pressure control module; during the test process, the positive and negative pressure collector 4 monitors the pressure and flow data of the five-way positive and negative pressure gauges 16 in real time, and the positive and negative pressure collector 4 encapsulates the raw data:

[0074] Data formatting: convert each pressure value into hexadecimal text;

[0075] CRC16 checksum generation: Calculate the CRC16 checksum for the complete data frame and append it to the end of the data frame;

[0076] Data frame transmission: The encapsulated data frame is sent to the communicator 12 via the 485 communication protocol, and the communicator 12 forwards the data to the network switch 11;

[0077] The network switch 11 then transmits the received data frame to the main controller 6, which performs the following operations:

[0078] Checksum verification: Perform CRC16 checksum calculation on the data frame and compare it with the attached checksum to confirm the integrity of the data transmission. If the checksum fails, the retransmission mechanism is triggered.

[0079] Data parsing: After stripping the checksum, parse the hexadecimal value in 4-byte groups;

[0080] Real-time analysis: The analyzed pressure data is compared with the threshold value set by the host computer, and a fluctuation curve is dynamically generated. The sealing performance of the filter body 2 is determined by the stability of the curve;

[0081] The main controller 6 compares the analyzed flow data with the set value. If a deviation is detected, a correction instruction is generated and sent to the intelligent flow control valve 3 through a direct line to adjust the valve opening in real time to ensure that the test flow is stable throughout the entire process; at the same time, the pressure data is used to feedback and adjust the opening of the proportional valve 10 to achieve pressure-flow dual parameter control.

[0082] See attached Figure 3 -Attached Figure 8 , the data acquisition and analysis module supports six test mode data analysis:

[0083] Specify pressure mode: analyze pressure value, holding time and qualification judgment;

[0084] Step pressure mode: analyze the number of steps, number of cycles and single cycle / multi-cycle judgment;

[0085] Start-stop shock mode: analyze shock cycle times and interruption and continuation data;

[0086] Fatigue cycle mode: analysis time interval and test duration;

[0087] Factory test mode: Analyze the response characteristics of the air supply pressure step signal, including the linearity deviation between the input voltage and output pressure of the proportional valve 10, and the step response time of the positive and negative pressure collector 4;

[0088] Self-test mode: Analyzes the internal gas path sealing data of the equipment, including the internal leakage rate of the equipment and the adjustment accuracy fluctuation range of the proportional valve 10 at a pressure of 0.5MPa.

[0089] Specifically, in the specified pressure mode, the main controller 6 adjusts the test chamber pressure to the target value through the proportional valve 10. The positive and negative pressure collector 4 collects the pressure holding data from the five-way positive and negative pressure gauges 16, and transmits it to the network switch 11 after CRC16 verification. The main controller 6 analyzes the pressure fluctuation range and determines that it is qualified when the fluctuation value is ≤±1%;

[0090] Step pressure mode: The main controller 6 adjusts the output pressure of the proportional valve 10 in stages according to the preset number of steps and number of cycles. Based on the step data of the positive and negative pressure collector 4, if the single step deviation is ≤±2% and the difference between cycles is ≤±1.5%, it is judged as qualified;

[0091] Start-stop shock mode: the main controller 6 controls the proportional valve 10 to quickly switch between 0.5MPa and 0MPa for ≥100 cycles, and the positive and negative pressure collector 4 records the pressure decay curve and recovery time. It is judged to be qualified when the recovery time is ≤50ms and the overshoot is ≤5%;

[0092] In fatigue cycle mode, positive and negative pressure are switched periodically according to the set time interval and total duration. A time-pressure curve is drawn based on the 12 sets of data collected by the positive and negative pressure collector 4 at intervals. It is judged as qualified when there is no abnormal fluctuation of ≥10% throughout the process;

[0093] In the factory test mode, the main controller 6 sends a step voltage signal to test the linearity of the proportional valve 10. If the deviation is ≤±1.5%, it is judged to be qualified. The proportional valve 10 is used to instantly switch the pressure to test the step response time of the positive and negative pressure collector 4. If it is ≤30ms, it is judged to be qualified.

[0094] In the self-test mode, after closing the proportional valve 10, the bidirectional pressure pump 1 outputs 0.5 MPa to the gas storage tank assembly 18. The positive and negative pressure collector 4 monitors the leakage rate of the valve gas path front end. If it is ≤0.005 MPa / min, the sealing is judged to be qualified. The pressure fluctuation range of the proportional valve 10 at a fixed voltage is also measured. If the fluctuation is ≤±0.2%, the adjustment accuracy is judged to be qualified.

[0095] All modes send CRC16 check data frames to the network switch 11 through the communicator 12, and the main controller 6 completes data analysis, fluctuation curve generation and qualification determination.

[0096] See attached Figure 3 -Attached Figure 9 , a testing method for a positive and negative pressure universal filter testing device, comprising the following steps:

[0097] S1: Install the filter body 2 to be tested in the test chamber to ensure sealing;

[0098] S2: Set test parameters and start device self-test;

[0099] S3: Perform stress testing, including any of the following modes;

[0100] Specified pressure mode: adjust the step air pressure to the target value through the proportional valve 10;

[0101] Step pressure mode: adjust the pressure step by step in ≤5 steps;

[0102] Start-stop impact mode: cyclic execution of the change from "0→target pressure→maintaining pressure→0";

[0103] Fatigue cycle mode: periodically start and stop the pressure at fixed time intervals;

[0104] Factory test mode: detects the response characteristics of the air supply pressure step signal and verifies the dynamic adjustment performance of the proportional valve 10;

[0105] Self-test mode: disconnect the filter body 2 and directly connect the air path to test the internal sealing and pressure holding capacity of the equipment;

[0106] S4: Real-time monitoring of pressure and flow, collection of filtration efficiency and resistance data;

[0107] S5: If it is a complex working condition test, perform the positive and negative pressure alternation procedure and record the performance changes;

[0108] S6: The data acquisition and analysis module generates a test report and outputs the judgment results.

[0109] Specifically, in S1, the filter body 2 to be tested is fixed to the sealing position of the test chamber, and the airtightness of the test chamber is ensured by a quick-connect sealing interface; the air flow distribution device 13 inside the test chamber adjusts the angle of the air flow guide plate according to the specifications of the filter body 2 to ensure uniform airflow;

[0110] In S2, the test parameters are set on the upper computer interface of the main controller 6, the self-test mode is started, and the air circuit sealing is tested: the proportional valve 10 is closed, the bidirectional pressure pump 1 outputs 0.5MPa to the gas tank assembly 18, and the positive and negative pressure collector 4 monitors the pressure changes inside the equipment. If the leakage rate is ≤0.005MPa / min within 5 minutes, the sealing is judged to be qualified; component performance verification: the main controller 6 sends a fixed voltage to the proportional valve 10, and the positive and negative pressure collector 4 records the pressure fluctuation range. The fluctuation is ≤±0.2%, which determines that the adjustment accuracy is qualified.

[0111] In S3, the pressure mode is specified: the main controller 6 sends the instruction "0106" and the voltage value to the proportional valve 10, adjusting the test chamber pressure to the target value. The positive and negative pressure collector 4 collects 20 consecutive sets of data from the five-way positive and negative pressure gauges 16, and transmits them to the network switch 11 after CRC16 verification. The main controller 6 calculates the fluctuation value during the pressure holding time, and the value is considered qualified if it is ≤±1%;

[0112] Step pressure mode: The main controller 6 adjusts the proportional valve 10 in stages according to the preset number of steps and number of cycles. During each step pressure holding period, the positive and negative pressure collector 4 collects 12 groups of 4-byte data. The main controller 6 analyzes the single step deviation and the difference between cycles. If all meet the standards, it is judged to be qualified;

[0113] Start-stop shock mode: the main controller 6 controls the proportional valve 10 to quickly switch between 0MPa and 0.5MPa. The positive and negative pressure collector 4 records the decay curve and recovery time of each pressure interruption. If the recovery time is ≤50ms and the overshoot is ≤5%, it is judged to be qualified.

[0114] Fatigue cycle mode: positive and negative pressures are switched periodically according to fixed intervals and total durations. The positive and negative pressure collectors 4 collect data at intervals, and the main controller 6 draws a time-pressure curve. If there is no ≥10% mutation during the whole process, it is considered qualified.

[0115] Factory test mode: The main controller 6 sends a step voltage signal to the proportional valve 10, and the positive and negative pressure collector 4 records the output pressure linearity deviation; at the same time, the proportional valve 10 switches the pressure, and the positive and negative pressure collector 4 records the step response time;

[0116] Self-test mode: Disconnect the filter body 2, directly connect the test chamber air path, the bidirectional pressure pump 1 outputs 0.5MPa, the internal leakage rate of the positive and negative pressure collector 4 equipment and the adjustment accuracy of the proportional valve 10, if the fluctuation is ≤±0.2%, it is judged to be qualified.

[0117] In S4, the intelligent flow control valve 3 dynamically adjusts the flow according to the instruction of the main controller 6; the positive and negative pressure collector 4 sends the CRC16 check data frame to the network switch 11 through the communicator 12; the main controller 6 analyzes the actual value and synchronously collects the filtration efficiency and resistance data;

[0118] In S5, the positive and negative pressure alternation program is started: the vacuum generator 8 generates negative pressure through the vacuum control valve 9, and the proportional valve 10 outputs positive pressure. The two are periodically switched under the coordination of the main controller 6, and the positive and negative pressure collector 4 records the performance changes of the filter body 2 under the pressure mutation;

[0119] In S6, the master controller 6 integrates the flow data of the intelligent flow control valve 3 and the pressure / efficiency / resistance data of the positive and negative pressure collector 4 and performs the following operations:

[0120] Fluctuation analysis: draw pressure-time curve;

[0121] Qualified judgment: output a single result based on the preset threshold;

[0122] Report generation: Automatically summarize positive pressure, negative pressure and complex working condition test data, and generate a test report including curve graphs and judgment conclusions.

[0123] See attached Figure 3 When the specified pressure mode is selected in S3, the detection pressure value and fluctuation range are set; a step pressure signal is output through the proportional valve 10; whether the pressure drop exceeds the limit during the pressure holding time is determined, and a pass / fail result and the effective pressure holding time are output.

[0124] Specifically, the target detection pressure value and the allowable fluctuation range are set on the upper computer interface of the main controller 6, and the pressure holding time parameter is set at the same time; the voltage instruction is generated by the main controller 6 and sent to the proportional valve 10 through the proportional valve controller 5, where the instruction format is a hexadecimal data frame, and then the CRC16 check code of the complete instruction is calculated and appended to the end of the data frame. After receiving it, the proportional valve 10 outputs the step air pressure to the test chamber; in this process, the positive and negative pressure collector 4 monitors the data of the five-way positive and negative pressure gauges 16 in real time, collects 20 groups of pressure values ​​at fixed intervals during the pressure holding time, and sends them to the network switch 11 through the 485 communicator 12, and the main controller 6 verifies the validity of the check code, and triggers retransmission if it fails; if the fluctuation range of 20 consecutive groups of data is ≤±1%, it is judged to be qualified, and a report containing the effective pressure holding time and the judgment conclusion is generated.

[0125] See attached Figure 4 When the step pressure mode is selected in S3, set the number of steps ≤ 5, the pressure value of each step and the holding time; execute single cycle or multi-cycle mode; when a step test fails, pause and record the current cycle number, and continue to accumulate after manual intervention.

[0126] Specifically, when the step pressure mode is selected in S3, the main controller 6 sets the number of steps to no more than 5, the target pressure value for each step, and the holding time. The holding time can be set from 5 seconds to 300 seconds per step. The execution process is divided into two modes:

[0127] Single cycle mode: The proportional valve 10 outputs step pressure signals in sequence, increasing the pressure step by step according to the set steps, and the response time for each step switching is 200 milliseconds;

[0128] Multi-cycle mode: Repeat the single-cycle process, and the total number of cycles can be set from 1 to 10,000 times. After each cycle is completed, the data acquisition and analysis module records the current cumulative number of times. When a step test fails, the main controller 6 pauses the test and closes the proportional valve 10, while the five-way control valve 14 simultaneously cuts off the airflow, stores the current number of cycles, and triggers an audible and visual alarm. After manual intervention to troubleshoot the fault, the operator confirms the continuation instruction on the main controller 6, and the equipment continues to execute from the breakpoint step, and the cumulative number of cycles continues.

[0129] Output after the test is completed:

[0130] Qualification judgment: All step pressure decays meet the standards and the number of cycles is completed;

[0131] Failure determination: Mark the failure step position, actual holding time and number of cycles when interrupted;

[0132] Data recording: peak pressure, minimum pressure value, holding time error and cumulative number of cycles for each step;

[0133] The original data is encapsulated with a CRC16 check code, and the master controller 6 transmits the check code to the host computer to generate a pressure-step curve diagram.

[0134] See attached Figure 5 and attached Figure 6 When the start-stop impact mode is selected in S3, the target pressure value and the number of cycles are set; a single cycle executes the "0→target pressure→maintain pressure→0" process; the current number is recorded when the cycle is interrupted, and the accumulation is continued after manual intervention; when the fatigue cycle mode is selected in S3, the pressure start-stop time interval and the total test time are set; the pressure increase-maintain pressure-decrease process is executed periodically; the pressure decay curve is recorded in real time and the sealing failure point is determined.

[0135] Specifically, when the start-stop impact mode is selected in S3, the main controller 6 sets the target pressure value and the number of cycles, wherein the target pressure value is set in the range of 100 kPa to 2 MPa, and the number of cycles is set in the range of 1 to 10,000 times; the single cycle execution process is:

[0136] Pressure boosting stage: The proportional valve 10 receives the command from the master controller 6 and outputs a step pressure signal, increasing the pressure to the target value at a rate of 1 MPa / s;

[0137] Pressure holding stage: Maintain the target pressure for 30 seconds, and the positive and negative pressure collector 4 verifies the pressure decay rate at 100 samples per second;

[0138] Depressurization stage: the vacuum control valve 9 opens the negative pressure channel and the pressure drops to normal pressure within 200 milliseconds;

[0139] The total duration of a single loop is 60 seconds, and the interval between loops is 5 seconds;

[0140] If the pressure decay exceeds the limit or the device fails during the cycle:

[0141] Interrupt processing: the main controller 6 suspends the test, stores the current number of cycles, and triggers the sound and light alarm;

[0142] Reconnection process: After manual intervention to eliminate the fault, the operator confirms the reconnection instruction on the main controller 6 interface, and the equipment continues to execute the cycle from the breakpoint, and automatically reconnects after the cumulative number of times;

[0143] Test completion output: cycle completion status: actual number of completions / set number of completions; abnormal records: cycle number at the time of interruption, over-limit pressure value and failure pressure holding time; performance data: peak pressure of each cycle, average pressure rise rate and pressure relief response time;

[0144] The original data is encapsulated with a CRC16 check code, and the main controller 6 transmits the check code to the host computer to generate a pressure-time impact waveform.

[0145] When the fatigue cycle mode is selected in S3, the main controller 6 sets the pressure start and stop time interval, the single pressure holding time and the total test time.

[0146] Execution process:

[0147] Periodic cycle: Pressure increasing stage: the proportional valve 10 increases the pressure to the target pressure at a rate of 0.5 MPa / s, which takes 2 seconds;

[0148] Pressure holding stage: Maintain the target pressure for 5 seconds, and the positive and negative pressure collector 4 monitors the pressure decay at 100 samples per second;

[0149] Depressurization stage: the vacuum control valve 9 opens the negative pressure channel and the pressure drops to normal pressure within 300 milliseconds;

[0150] In this process, the total duration of a single loop is 10 seconds, and the loop interval is zero to achieve seamless looping;

[0151] Real-time monitoring:

[0152] The data acquisition and analysis module records the pressure value in MPa every 100 milliseconds and generates a pressure-time decay curve; compares the peak pressure difference of adjacent cycles according to the formula: Calculate the decay rate, where ΔP is the percentage decay rate, Pn and Pn+1 are the peak pressure values ​​of two consecutive tests, and the numerator Pn-Pn+1 is equivalent to the pressure loss; when the decay rate exceeds 5% for three consecutive cycles, it is determined to be the seal failure point and the timestamp is recorded with a timestamp accuracy of seconds;

[0153] Interruption and continuation:

[0154] If the total test time does not reach the set value but the seal failure has been triggered, the test will be automatically terminated; if the equipment fails, the test will be paused and the current number of cycles executed will be saved. After manual intervention, the accumulated test time will be continued from the interruption point.

[0155] Test completion output:

[0156] Seal failure point: mark the failure occurrence time and the corresponding cycle number;

[0157] Performance report: Generate peak pressure change curve, average decay rate, and effective cycle number, where the horizontal axis of the curve is time in hours and the vertical axis is pressure in MPa;

[0158] Raw data: CRC16 checksum package, stored in CSV format and PDF curve chart.

[0159] See attached Figure 7 -Attached Figure 11 When the factory test mode is selected in S3, a 1V to 10V step voltage signal is input to the proportional valve 10 to verify whether the output pressure matches the linear correspondence of 100kPa to 2MPa. The response time of the positive and negative pressure collector 4 from the initial supply pressure value to the detection pressure change is recorded. The fluctuation of the supply pressure step signal curve is analyzed by the host computer software, and a linear deviation report is output. When the self-test mode is selected in S3, the filter body 2 is disconnected, the test chamber gas path is directly connected to the atmosphere, and a pressure of 0.5MPa is applied inside the equipment and maintained for 10 seconds. If the pressure drop is greater than 0.5kPa, it is determined that the gas path leaks abnormally. At the same time, the fluctuation range of the adjustment accuracy of the proportional valve 10 is monitored.

[0160] Specifically, in the factory test mode, the operator needs to input a step voltage signal of 1V to 10V to the proportional valve 10. The system will automatically verify whether the output pressure follows the linear correspondence between 100kPa and 2MPa. During this process, the positive and negative pressure collector 4 will record the response time from the initial supply pressure value to the detection pressure change. The upper computer software collects the supply pressure step signal curve in real time, analyzes its fluctuation characteristics and generates a linear deviation report to ensure that the accuracy of the pressure control module meets the design standards.

[0161] In the factory test mode, the step voltage signal parameters are set on the upper computer interface of the main controller 6, and the main controller 6 sends a step voltage instruction to the proportional valve 10. During this process, the positive and negative pressure collector 4 records the response process from the initial value of the supply pressure to the target pressure in real time, and measures the response time of the pressure rising from 10% to 90%. If it is ≤30ms, it is judged to be qualified, and the CRC16 check data frame is sent to the network switch 11 through the communicator 12. The main controller 6 synchronously receives and parses the data to draw the supply pressure step signal curve, calculates the full linear deviation, and if the deviation is ≤±1.5%, it is judged to be qualified, and generates a report including the response time and linear deviation value.

[0162] In the self-test mode, disconnect the filter body 2 and connect the test chamber gas line directly to the atmosphere:

[0163] Leakage test: bidirectional pressure pump 1 outputs 0.5 MPa to the air storage tank assembly 18, and closes the proportional valve 10;

[0164] Pressure monitoring: The positive and negative pressure collector 4 monitors the pressure changes inside the equipment. If the pressure drop is greater than 0.5kPa within 10 seconds of pressure maintenance, it is determined that the gas circuit is leaking abnormally;

[0165] Adjustment accuracy test: the main controller 6 sends a fixed voltage to the proportional valve 10, and the positive and negative pressure collector 4 records the pressure fluctuation range. When the fluctuation is greater than ±0.2%, the proportional valve 10 is marked as abnormally adjusted;

[0166] Result output: All data are transmitted to the network switch 11 after CRC16 verification, and the main controller 6 generates a self-test report including the leakage rate and the adjustment accuracy fluctuation range.

[0167] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A positive and negative pressure universal filter testing equipment, characterized in that: The invention comprises an integrated machine (17), wherein a filter body (2) is provided on the outside of the integrated machine (17), a positive and negative pressure gauge (16) is installed on the integrated machine (17), an air intake interface (15) is provided on the integrated machine (17), an air storage tank assembly (18) is installed on the air storage tank assembly (18), a bidirectional pressure pump (1) is installed on the air storage tank assembly (18), an air intake boost valve assembly (19) is installed on the integrated machine (17), an intelligent flow regulating valve (3), a positive and negative pressure collector (4), a proportional valve controller (5), a master controller (6), a vacuum generator air intake adjustment (7), a vacuum generator The invention relates to a vacuum generator (8), a vacuum control valve (9), a proportional valve (10), a network switch (11), a communicator (12), an air flow distribution device (13) and a control valve (14), wherein the vacuum generator (8) is electrically connected to the vacuum control valve (9), the main controller (6) is electrically connected to the vacuum control valve (9), the communicator (12) and the control valve (14), the communicator (12) is electrically connected to the positive and negative pressure collector (4), the proportional valve controller (5) and the network switch (11), the positive and negative pressure collector (4) is electrically connected to the positive and negative pressure gauges (16), and the network switch (11) is electrically connected to the all-in-one machine (17).

2. A positive and negative pressure universal filter testing device according to claim 1, characterized in that: Includes the following modules: The pressure control module comprises a positive and negative pressure bidirectional pressure pump (1), a positive and negative pressure collector (4) and a master controller (6); the bidirectional pressure pump (1) is capable of outputting positive or negative pressure airflow, the positive and negative pressure collector (4) monitors the pressure of the integrated machine (17) in real time and feeds back to the master controller (6), and the master controller (6) automatically adjusts the output of the bidirectional pressure pump (1) according to the feedback data; Flow regulating module: comprising an intelligent flow regulating valve (3) and a positive and negative pressure collector (4), wherein the intelligent flow regulating valve (3) automatically adjusts the flow according to the type of the filter body (2) and the test conditions, and the positive and negative pressure collector (4) monitors the flow data in real time and transmits it to the data acquisition and analysis module; The test chamber module adopts a sealed pressure-resistant structure, and is provided with an adjustable air flow distribution device (13) inside, and is used to install the filter body (2) to be tested and withstand pressure changes under positive and negative pressure conditions; Data acquisition and analysis module: including a communicator (12) and a network switch (11), collecting pressure, flow, filtration efficiency and resistance data in real time and generating a test report; Each module is connected through a standardized interface and can be combined and expanded.

3. The positive and negative pressure universal filter testing device according to claim 1, characterized in that: The intelligent flow regulating valve (3) is directly connected to the main controller (6) and automatically adapts the flow according to the preset specification parameters of the filter body (2); the positive and negative pressure collector (4) uses a CRC16 check code to transmit data to the data acquisition and analysis module.

4. The positive and negative pressure universal filter testing device according to claim 1, characterized in that: The airflow distribution device (13) of the test chamber module is a porous adjustable flow guide structure, which supports uniform airflow distribution under positive and negative pressure alternating working conditions; the test chamber sealing structure adopts a quick installation interface to avoid leakage errors caused by repeated installation.

5. The positive and negative pressure universal filter testing equipment according to claim 1, characterized in that: The data acquisition and analysis module supports six test mode data analysis: Specify pressure mode: analyze pressure value, holding time and qualification judgment; Step pressure mode: analyze the number of steps, number of cycles and single cycle / multi-cycle judgment; Start-stop shock mode: analyze shock cycle times and interruption and continuation data; Fatigue cycle mode: analysis time interval and test duration; Factory test mode: Analyze the response characteristics of the air supply pressure step signal, including the linearity deviation between the input voltage and output pressure of the proportional valve (10), and the step response time of the positive and negative pressure collector (4); Self-check mode: Analyze the internal gas path sealing data of the equipment, including the internal leakage rate of the equipment and the adjustment accuracy fluctuation range of the proportional valve (10) at a pressure of 0.5 MPa.

6. A method for testing a positive and negative pressure universal filter test device, used for a positive and negative pressure universal filter test device according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1: Install the filter body (2) to be tested in the test chamber to ensure sealing; S2: Set test parameters and start device self-test; S3: Perform stress testing, including any of the following modes; Specified pressure mode: adjust the step air pressure to the target value through the proportional valve (10); Step pressure mode: adjust the pressure step by step in ≤5 steps; Start-stop impact mode: cyclic execution of "0→target pressure→maintaining pressure→0" changes; Fatigue cycle mode: periodically start and stop the pressure at fixed time intervals; Factory test mode: detect the response characteristics of the air supply pressure step signal and verify the dynamic adjustment performance of the proportional valve (10); Self-test mode: disconnect the filter body (2) and directly connect the air path to test the internal sealing and pressure holding capacity of the equipment; S4: Real-time monitoring of pressure and flow, collection of filtration efficiency and resistance data; S5: If it is a complex working condition test, perform the positive and negative pressure alternation procedure and record the performance changes; S6: The data acquisition and analysis module generates a test report and outputs the judgment results.

7. The testing method of a positive and negative pressure universal filter testing device according to claim 6, characterized in that: When the designated pressure mode is selected in S3, the detection pressure value and the fluctuation range are set; a step pressure signal is output through the proportional valve (10); and whether the pressure drop exceeds the limit during the pressure holding time is determined, and a pass / fail result and the effective pressure holding time are output.

8. The testing method of a positive and negative pressure universal filter testing device according to claim 6, characterized in that: When step pressure mode is selected in S3, set the number of steps to ≤ 5, the pressure value of each step and the holding time; execute single cycle or multi-cycle mode; when a step test fails, pause and record the current cycle number, and continue accumulation after manual intervention.

9. The testing method of a positive and negative pressure universal filter testing device according to claim 6, characterized in that: When the start-stop impact mode is selected in S3, the target pressure value and the number of cycles are set; a single cycle executes the "0→target pressure→maintain pressure→0" process; the current number is recorded when the cycle is interrupted, and the accumulation continues after manual intervention; when the fatigue cycle mode is selected in S3, the pressure start-stop time interval and the total test time are set; the pressure increase-maintain pressure-decrease process is periodically executed; the pressure decay curve is recorded in real time and the seal failure point is determined.

10. The testing method of a positive and negative pressure universal filter testing device according to claim 6, characterized in that: When the factory test mode is selected in S3, a 1V to 10V step voltage signal is input to the proportional valve (10) to verify whether the output pressure matches the linear correspondence of 100kPa to 2MPa, and the response time of the positive and negative pressure collector (4) from the initial value of the supply pressure to the detection pressure change is recorded. The fluctuation of the supply pressure step signal curve is analyzed by the upper computer software, and a linear deviation report is output; when the self-test mode is selected in S3, the filter body (2) is disconnected, the test chamber air path is directly connected to the atmosphere, and a pressure of 0.5MPa is applied inside the device and maintained for 10 seconds. If the pressure drop is greater than 0.5kPa, it is determined that the air path leakage is abnormal, and the adjustment accuracy fluctuation range of the proportional valve (10) is monitored at the same time.

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