A test system and method for PCV one-way valve and venturi junction

Abstract

The application discloses a test system and method for PCV one-way valves and Venturi joints, and the system is configured to include a positive pressure pipeline test system for PCV one-way valve forward pressure loss test and Venturi joint desorption test. The system realizes the PCV one-way valve forward pressure loss test and the Venturi joint desorption test, and does not need to replace the test system, thereby improving the test efficiency.

Description

Technical Field

[0001] This invention belongs to the field of testing, and in particular relates to a testing system and method for PCV check valves and venturi connectors. Background Technology

[0002] The integrated crankcase ventilation valve (PCV check valve) is a key connecting component of the engine crankcase ventilation system, and its performance directly affects the engine's operational stability and emission standards. During engine operation, blow-by gas from the piston rings can increase the pressure inside the crankcase, easily leading to malfunctions such as oil seal leakage and valve cover seal failure. The PCV check valve can discharge blow-by gas in real time, maintaining pressure balance inside and outside the crankcase and preventing oil leakage; at the same time, it limits excessive loss of oil vapor, preventing oil deterioration due to oxidation and dilution, and ensuring the stable operation of the lubrication system. In addition, when backfire occurs in the engine, the valve can quickly close, blocking the impact of reverse airflow and preventing safety hazards caused by a sudden increase in crankcase pressure. The PCV check valve can dynamically adjust the ventilation volume according to engine operating conditions: at idle speed or low load, the intake manifold vacuum is high, the valve opening decreases, and the amount of blow-by gas entering is controlled to maintain a stable air-fuel ratio; at high speed and high load, the vacuum decreases, the valve opening increases, and the blow-by gas is ensured to burn completely. This adjustment function improves intake air quality, prevents the throttle body from freezing due to low-temperature fuel vapor buildup, enhances combustion efficiency, and reduces fuel consumption and pollutant emissions. PCV one-way valve failure can lead to a series of problems, including decreased engine power, increased fuel consumption, and excessive emissions.

[0003] The venturi coupling for carbon canister desorption (hereinafter referred to as the Venturi coupling) is a core negative pressure generating component in the evaporative fuel absorption control system (EVAP system) of turbocharged and direct injection engines. It specifically addresses the problem of insufficient positive pressure in the intake manifold to desorb carbon canisters under turbocharged conditions. The Venturi coupling utilizes the Venturi effect: when high-pressure airflow passes through a constricted throat, the flow velocity surges, and the pressure drops sharply, creating a stable negative pressure at the interface on the carbon canister side. This drives the carbon canister to desorb fuel vapor, ensuring the "regeneration" of the carbon canister. Compared to simple manifold vacuum, the Venturi coupling provides stronger and more continuous negative pressure, especially under high loads, where its desorption capacity can be improved by more than 30%. This ensures effective desorption of the carbon canister under all operating conditions, preventing fuel vapor escape and meeting China VI emission standards. Venturi coupling failure can lead to carbon canister saturation, fuel leakage, excessive emissions, and abnormal power and fuel consumption.

[0004] Normally, PCV check valves and Venturi connectors are installed on their respective piping systems, with only a standard vent connector provided on the air filter system. Therefore, functional testing of the PCV check valve and Venturi connector is not involved. However, in many high-end vehicles, due to the compact engine compartment layout, there is no space to install them on the crankcase ventilation pipe and carbon canister desorption pipe. In this case, the PCV check valve and Venturi connector must be integrated into the air filter system. This places the responsibility of the air filter system manufacturer to test the performance design of the PCV check valve and Venturi connector. Since the PCV check valve and Venturi connector are not standard equipment on the air filter system and are only used in certain specific projects, testing is usually done on a simple test bench, with performance tests performed separately on the PCV check valve and Venturi connector, resulting in low testing efficiency. Summary of the Invention

[0005] To address the technical problems existing in the prior art, this invention provides a testing system for PCV check valves and venturi fittings, which can perform performance testing on both products.

[0006] The system is configured to include a positive pressure pipeline testing system for PCV check valve positive pressure loss testing and Venturi joint desorption testing; The positive pressure pipeline testing system includes a ball valve, an air filter, a compressed air switch, a mist separator, an air tank, an electro-proportional valve, a first pneumatic ball valve, a first positive pressure sensor, a second positive pressure sensor, a positive pressure flow test outlet, a positive pressure flow test return port, a large-range mass flow meter, a first pneumatic control valve, a second pneumatic control valve, a Venturi suction port, and pipelines. An air filter, compressed air switch, mist separator, air tank, electro-proportional valve, first pneumatic ball valve, first positive pressure sensor, and second positive pressure sensor are sequentially connected via pipelines between the ball valve and the positive pressure flow test outlet; the second positive pressure sensor, large-range mass flow meter, and second pneumatic control valve are sequentially connected via pipelines between the positive pressure flow test return port and the Venturi suction port; the first pneumatic control valve is connected to the large-range mass flow meter via pipeline; During the positive pressure loss test of the PCV check valve, the PCV check valve under test is connected to the positive pressure flow test outlet and the positive pressure flow test return port through pipelines respectively. During the desorption test of the Venturi connector, the drive port of the Venturi connector under test is connected to the positive pressure flow test outlet through a pipeline, and the suction port of the Venturi connector under test is connected to the Venturi suction port through a pipeline.

[0007] Furthermore, it is also configured to include a shared piping system, which includes a third positive pressure sensor, a solenoid valve, a positive and negative pressure alternating test port, and piping. The positive pressure pipeline testing system also includes a first positive pressure pneumatic control solenoid valve and a second positive pressure pneumatic control solenoid valve; One end of the first positive pressure pneumatic solenoid valve and the second positive pressure pneumatic solenoid valve are connected to the end of the electric proportional valve and the first pneumatic ball valve through a pipeline. The other end of the first positive pressure pneumatic solenoid valve and the second positive pressure pneumatic solenoid valve are connected to one end of the third positive pressure sensor through a pipeline. The solenoid valve is located between the other end of the third positive pressure sensor and the positive and negative pressure alternating test port, and is connected to the third positive pressure sensor and the positive and negative pressure alternating test port through pipelines respectively. The positive pressure pipeline testing system and the shared pipeline system are used together for the positive pulse test of the PCV check valve. During the positive pulse test of the PCV check valve, the positive and negative pressure alternating test port is connected to the PCV check valve under test through the pipeline.

[0008] Furthermore, the pressure range of the first positive pressure sensor and the second positive pressure sensor is -1 to 9 bar.

[0009] Furthermore, the measurement range of the large-range mass flow meter is 1.5~150L / min.

[0010] This invention also provides a test method for PCV check valves and venturi connectors. This method is based on the test system provided by this invention and includes a forward pressure loss test for the PCV check valve and a desorption test for the venturi connector. During the PCV check valve forward pressure loss test, the first pneumatic control valve is open and the second pneumatic control valve is closed. Compressed air passes through a ball valve, air filter, compressed air switch, micro-mist separator, air tank, electro-proportional valve, first pneumatic control ball valve, first positive pressure sensor, positive pressure flow test outlet, PCV check valve under test, positive pressure flow test return port, second positive pressure sensor, large-range mass flow meter, and the first pneumatic control valve before being discharged into the external atmosphere. The pressure readings of the first and second positive pressure sensors upstream and downstream of the PCV check valve under test are collected respectively. The two pressure values ​​are subtracted, and the result is compared with the PCV check valve forward pressure loss standard value. If the result is less than or equal to the PCV check valve forward pressure loss standard value, the PCV check valve under test passes the pressure loss test; otherwise, it fails. During the Venturi joint desorption test, the first pneumatic control valve is closed and the second pneumatic control valve is open. Compressed air flows into the drive port of the Venturi joint under test after passing through the ball valve, air filter, compressed air switch, micro-mist separator, air tank, electro-proportional valve, first pneumatic control ball valve, first positive pressure sensor, and positive pressure flow test outlet. Atmospheric air flows into the suction port of the Venturi joint under test after passing through the second positive pressure sensor, large-range mass flow meter, second pneumatic control valve, and Venturi suction port. When a specified positive pressure is applied to the drive port, the suction port generates a suction force, and the reading of the large-range mass flow meter at this time is the desorbed flow rate.

[0011] The testing method provided by this invention is also used for positive pulse testing of PCV check valves. During the positive pulse test of PCV check valves, a positive pressure pulse is provided to the PCV check valve under test. In this test state, the first pneumatic ball valve is closed, and the first positive pressure pneumatic solenoid valve and the second positive pressure pneumatic solenoid valve are open. Compressed air flows through the ball valve, air filter, compressed air switch, micro-mist separator, air tank, electro-proportional valve, first positive pressure pneumatic solenoid valve, second positive pressure pneumatic solenoid valve, third positive pressure sensor, solenoid valve, positive and negative pressure alternating test port, and the PCV check valve under test before being discharged into the external atmosphere.

[0012] The testing system provided by this invention is applied in an air filter system integrating a crankcase forced ventilation valve and a carbon canister desorption venturi joint for PCV check valves and venturi joints.

[0013] Compared with the prior art, the present invention has the following beneficial effects: This system enables forward pressure loss testing of PCV check valves and desorption testing of Venturi connectors without requiring replacement of the testing system, thus improving testing efficiency.

[0014] This system is also equipped with a shared piping system to build a positive pulse test loop for the PCV check valve with the positive piping test system, providing the required positive pressure pulse for the PCV check valve during the positive pulse test. Attached Figure Description

[0015] To more clearly illustrate the embodiments of this application, the accompanying drawings used or involved in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application, and other drawings can be obtained based on these drawings without creative effort: Figure 1 This is a schematic diagram of the hardware system of the present invention; Figure 2 This is a schematic diagram of the positive pressure pipeline testing system of the present invention; Figure 3 This is a schematic diagram of the negative pressure pipeline testing system of the present invention; Figure 4 This is a schematic diagram of the shared piping system of the present invention; Figure 5 This is a schematic diagram of the positive pressure loss test of the PCV check valve of the present invention; Figure 6 This is a schematic diagram of the Venturi joint desorption test of the present invention; Figure 7 This is a schematic diagram of the negative pressure leakage test of the PCV check valve of the present invention; Figure 8 This is a schematic diagram of the positive and negative pressure pulse test of the PCV check valve of the present invention; Figure 9This is a schematic diagram of the positive pressure pulse test of the PCV check valve of the present invention; Figure 10 This is a schematic diagram of the negative pressure pulse test of the PCV check valve of the present invention. Detailed Implementation

[0016] This section describes the invention more fully with reference to the accompanying drawings, in which illustrative embodiments of the invention are shown. However, the invention is also embodied in many different forms and should not be construed as limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure is thorough and complete, and to fully convey the scope of the invention to those skilled in the art.

[0017] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprising” and “including,” as used herein, specify the presence of the illustrated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof.

[0018] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0019] In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0020] Unless defined to the contrary, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It will be further understood that terms such as those defined in common dictionaries should be interpreted as having the meaning consistent with their meaning in the context of the relevant field, and will not be interpreted in an idealized or highly formal sense unless specifically defined herein.

[0021] The testing system provided by this invention can be used for performance testing of two products: PCV check valves and Venturi connectors. The performance testing of PCV check valves includes PCV positive pressure loss testing, PCV check valve negative pressure leakage testing, and PCV check valve positive and negative pressure pulse testing. The performance testing of Venturi connectors includes Venturi connector desorption testing.

[0022] This testing system mainly consists of three parts: a positive pressure pipeline testing system, a negative pressure pipeline testing system, and a shared pipeline system.

[0023] Please refer to Figure 1 , 2 The positive pressure pipeline testing system includes a ball valve 1, an air filter 2, a compressed air switch 3, a mist separator 4, an air tank 5, an electro-proportional valve 6, a first positive pressure pneumatic control solenoid valve 7-1, a second positive pressure pneumatic control solenoid valve 7-2, a first pneumatic control ball valve 8, a first positive pressure sensor 9-1, a positive pressure flow test outlet 10, a positive pressure flow test return port 11, a second positive pressure sensor 9-2, a large-range mass flow meter 12, a first pneumatic control valve 13, a second pneumatic control valve 14, a Venturi suction port 16, and pipelines.

[0024] The function of ball valve 1 is to open and close the compressed air supply. When open, it operates the positive pressure pipeline system; when closed, it operates the negative pressure pipeline system. The function of air filter 2 is to filter the compressed air and prevent dust from entering the test pipeline. The function of compressed air switch 3 is to automatically release pressure when the resistance of the test piece is too high, thus protecting the system. The function of mist separator 4 is to separate air and water in the compressed air, preventing water vapor from adhering to and corroding the metal pipeline. The function of air tank 5 is to store compressed air and stabilize the pressure. The function of electro-proportional valve 6 is to control the flow rate of compressed air. The function of the first pneumatic ball valve 8 and the second pneumatic valve 14 is to open and close the corresponding test pipeline and switch to other test pipelines to meet other test requirements.

[0025] The functions of the positive pressure pipeline testing system include: 1) independently completing the positive pressure loss test of the PCV check valve; 2) independently completing the venturi joint desorption test; and 3) combining with the negative pressure pipeline testing system and the shared pipeline system to complete the positive and negative pulse test of the PCV check valve.

[0026] Please refer to Figure 2 , Figure 5During the positive pressure loss test of the PCV check valve, the airflow direction is as shown by the arrow. The first pneumatic control valve 13 is open, the second pneumatic control valve 14 is closed, and the first positive pressure pneumatic control solenoid valve 7-1 and the second positive pressure pneumatic control solenoid valve 7-2 are closed. The compressed air from the outside passes through the ball valve 1, air filter 2, compressed air switch 3, micro-mist separator 4, air tank 5, electro-proportional valve 6, first pneumatic control ball valve 8, first positive pressure sensor 9-1, positive pressure flow test outlet 10, PCV check valve 15a under test, positive pressure flow test return port 11, second positive pressure sensor 92, large range mass flow meter 12, and first pneumatic control valve 13, and is finally discharged into the outside atmosphere. External compressed air, approximately 8 bar, is used to generate a stable airflow required for the test after being stabilized by the air tank 5 and regulated by the electro-proportional valve 6. Pressure readings from the positive pressure sensors 9-1 and 9-2 upstream and downstream of the PCV check valve 15a under test are collected. The difference between these two values ​​is the forward pressure loss test result for the PCV check valve 15a. Whether the pressure loss meets the requirements is determined based on the performance of the PCV check valve under test. One test condition provided in this paper is: room temperature, test flow rate 100 L / min, and a pressure loss of ≤0.8 kPa for the check valve. In other words, the difference between the pressure values ​​from the first positive pressure sensor 9-1 and the second positive pressure sensor 9-2 is ≤0.8 kPa, indicating that the forward pressure loss of the PCV check valve under test meets the requirements.

[0027] Because both the first positive pressure sensor 9-1 and the second positive pressure sensor 9-2 detect positive pressure, it is called positive pressure loss.

[0028] Please refer to Figure 2 , Figure 6During the Venturi connector desorption test, the first pneumatic control valve 13 is closed, the second pneumatic control valve 14 is open, and the first positive pressure pneumatic control solenoid valve 7-1 and the second positive pressure pneumatic control solenoid valve 7-2 are closed. The ball valve 1, air filter 2, compressed air switch 3, mist separator 4, air tank 5, electro-proportional valve 6, first pneumatic control ball valve 8, first positive pressure sensor 9-1, and positive pressure flow test outlet 10 constitute the Venturi pressure input pipeline. Compressed air from outside flows into the drive port 15b-1 of the Venturi connector 15b under test via the ball valve 1, air filter 2, compressed air switch 3, mist separator 4, air tank 5, electro-proportional valve 6, first pneumatic control ball valve 8, first positive pressure sensor 9-1, and positive pressure flow test outlet 10. The Venturi desorption flow detection pipeline consists of a first positive pressure sensor 9-2, a large-range mass flow meter 12, and a second pneumatic control valve 14. Atmospheric air flows into the suction port 15b-2 of the Venturi connector 15b under test after passing through the second positive pressure sensor 9-2, the large-range mass flow meter 12, the second pneumatic control valve 14, and the Venturi suction port 16. The external compressed air is approximately 8 bar, and the positive pressure required for the test can be generated after being stabilized by the air tank 5 and regulated by the electro-proportional valve 6.

[0029] The desorption flow rate test utilizes the Venturi effect principle. When a specified positive pressure is applied to the drive port 15b-1, due to the special structure of the Venturi connector, a suction force is generated at the suction port 15b-2. Since the drive port 15b-1 and the first positive pressure sensor 9-1 are connected by pipes of equal diameter and are very close, the pressures at these two locations are equal. Compressed gas flows into the pipeline through ball valve 1, creating positive pressure in the pipeline. This positive pressure is then supplied to the drive port 15b-1 via the first positive pressure sensor 9-1 and the pipeline. At this time, the suction port 15b-2 generates a suction force. Since the suction port 15b-2 and the large-range mass flow meter 12 are connected in series, the flow meter reading is the desorbed flow rate. The requirements for the desorption performance of the Venturi connector are determined based on the performance of the Venturi connector.

[0030] Please refer to Figure 1 , Figure 3 The negative pressure pipeline testing system consists of a negative pressure flow test port 17, a small-range mass flow meter 18, a second pneumatic control solenoid valve 19, a negative pressure sensor 20, a pressure stabilizing tank 21, a first negative pressure pneumatic control solenoid valve 22-1, a second negative pressure pneumatic control solenoid valve 22-2, a vacuum electro-proportional valve 23, a vacuum tank 24, an oil mist filter 25, a vacuum pump 26, and pipelines.

[0031] The functions of the negative pressure pipeline testing system include: 1) independently completing the leakage test of the PCV check valve, and 2) combining with the positive pressure pipeline testing system and the shared pipeline system to complete the positive and negative pulse test of the PCV check valve.

[0032] Please refer to Figure 3 , Figure 7 When performing a negative pressure leakage test on a PCV check valve, the PCV check valve 15a under test must be placed in a high and low temperature environment test chamber. The leakage test usually requires testing leakage under three operating conditions: low temperature, normal temperature and high temperature. Therefore, the PCV check valve 15a under test needs to be placed in a high and low temperature environment test chamber to provide the required low temperature, normal temperature and high temperature for the test.

[0033] Negative pressure flow test port 17 is connected to the experimental chamber. Vacuum pump 26 is activated to evacuate air from the experimental chamber, creating a negative pressure. During evacuation, the air in the experimental chamber passes through negative pressure flow test port 17, small-range mass flow meter 18, second pneumatic control solenoid valve 19, negative pressure sensor 20, pressure stabilizing tank 21, vacuum electro-proportional valve 23, vacuum tank 24, and vacuum pump 26 before being discharged into the external atmosphere. After being regulated by vacuum tank 24 and pressure stabilizing tank 21, the air in the experimental chamber is brought to an initial negative pressure of -90 kPa to close the tested PCV check valve 15a. Then, vacuum electro-proportional valve 23 automatically adjusts to a small opening, maintaining the pressure of negative pressure sensor 20 at the set value (e.g., -5 kPa), ensuring that the tested PCV check valve 15a is just closed. At this point, the flow rate indicated by small-range mass flow meter 18 is the negative pressure leakage. The air flow direction is as follows... Figure 7 As indicated by the arrows in the diagram. In this example, the maximum allowable leakage is ≤0.75L / min at 150℃, ≤1.1L / min at 23℃, and ≤4L / min at -30℃; the specific maximum leakage is set according to the PCV check valve 15a under test.

[0034] The function of the pressure stabilizing tank 21 is to stabilize the pressure and eliminate pressure fluctuations. The function of the vacuum tank 24 is to store the negative pressure of the vacuum pump. The function of the vacuum pump 26 is to draw in air to create negative pressure in the pipeline and test chamber to meet the test conditions.

[0035] Please refer to Figure 1 , Figure 4 The shared piping system includes a third positive pressure sensor 27, a solenoid valve 28, a positive and negative pressure alternating test port 29, and piping. The shared piping system, combined with the positive pressure piping test system and the negative pressure piping test system, can perform positive and negative pulse tests on the PCV check valve.

[0036] Please refer to Figure 2 , Figure 3 , Figure 8 The principle behind the positive and negative pressure pulses in this system is as follows: airflow direction... Figure 8As shown by the arrowed curves, different pressures and frequencies of positive and negative pressures are achieved through the interaction of the first positive pressure pneumatic control solenoid valve 7-1, the second positive pressure pneumatic control solenoid valve 7-2, the first negative pressure pneumatic control solenoid valve 22-1, and the second negative pressure pneumatic control solenoid valve 22-2. Throughout the process, the electro-proportional valve 6, the vacuum electro-proportional valve 23, the first positive pressure sensor 9-1, the second positive pressure sensor 9-2, the third positive pressure sensor 27, and the negative pressure sensor 20 form a closed-loop control. Under the action of a given output electrical signal, the opening sizes of the electro-proportional valve 6 and the vacuum electro-proportional valve 23 continuously change, resulting in the test pressure waveform. During the PCV one-way valve positive and negative pressure pulse test, the test piece must be placed in a high and low temperature environment test chamber to meet the testing requirements of different temperature conditions.

[0037] Please refer to Figure 2 , Figure 9 The positive pressure pulse test uses a combination of a positive pressure pipeline testing system and a shared pipeline system. During testing, the first pneumatic ball valve 8 is closed, while the first positive pressure pneumatic solenoid valve 7-1 and the second positive pressure pneumatic solenoid valve 7-2 are open. External compressed air flows through ball valve 1, air filter 2, compressed air switch 3, mist separator 4, air tank 5, electro-proportional valve 6, first positive pressure pneumatic solenoid valve 7-1, second positive pressure pneumatic solenoid valve 7-2, third positive pressure sensor 27, solenoid valve 28, alternating positive and negative pressure test port 29, and the PCV check valve 15a under test, finally being discharged into the external atmosphere. The air flow direction is as follows: Figure 9 As indicated by the arrow.

[0038] Compressed air, after passing through the positive pressure pipeline testing system, acts on the PCV check valve 15a under test. The pressure formed in the pipeline is positive pressure, therefore the pulse supplied to the PCV check valve 15a under test is a positive pulse. When the pressure in the pipeline reaches a certain positive pressure value, it indicates that the positive pressure pulse mode of the system is activated, and the system provides a positive pressure pulse to the PCV check valve 15a under test. For example, if the pressure in the pipeline is 10 kPa, this pressure can be understood as the driving force of the positive pulse. As long as the positive pulse mode is switched, the pressure in the pipeline will be 10 kPa, which is the driving force for the opening mode. The driving force of the positive pulse can be any value; the 10 kPa described here is an example.

[0039] Please refer to Figure 3 , Figure 10The negative pressure pulse test uses a combination of a negative pressure pipeline testing system and a shared pipeline system. During testing, the second pneumatic solenoid valve 19 is closed, while the first negative pressure pneumatic solenoid valve 22-1 and the second negative pressure pneumatic solenoid valve 22-2 are open. Airflow passes through the PCV check valve 15a under test, the positive and negative pressure alternating test port 29, the solenoid valve 28, the third positive pressure sensor 27, the first negative pressure pneumatic solenoid valve 22-1, the second negative pressure pneumatic solenoid valve 22-2, the vacuum electro-proportional valve 23, the vacuum tank 24, the oil mist filter 25, and the vacuum pump 26. The airflow direction is as follows: Figure 10 As indicated by the arrow.

[0040] During a negative pressure pulse, vacuum pump 26 is activated, drawing in air that has entered the pipeline through the tested PCV check valve 15a. This creates negative pressure within the pipeline, thus providing a negative pulse to the tested PCV check valve 15a. When the pressure within the pipeline reaches a certain negative pressure value, it indicates that the system's negative pressure pulse mode has been activated, at which point the system provides a negative pressure pulse to the tested PCV check valve 15a. For example, if the pressure within the pipeline is -90 kPa, this pressure can be considered the driving force of the negative pulse. Switching to the negative pulse mode will result in a pressure of -90 kPa within the pipeline, representing the driving force for the open operation. The driving force of the negative pulse can be any value; the -90 kPa described here is an example.

[0041] The frequency of the positive and negative pressure pulse switching is 1Hz.

[0042] The requirements for positive and negative pressure pulse tests are as follows: Under maximum negative pressure of -90 kPa and positive pressure of 10 kPa, ensure the check valve plate is fully open and closed, with a test cycle frequency of 1 Hz: Under temperature conditions of 150°C±5°C, the number of opening and closing cycles was completed 100,000; Under temperature conditions of 110°C±5°C, the number of opening and closing cycles was completed 2,600,000. Under temperature conditions of -30°C±5°C, the number of opening and closing cycles was completed 300,000; Under temperature conditions of -40°C±5°C, 30,000 opening and closing cycles were completed; After the positive and negative pressure pulse test, the positive pressure loss and negative pressure leakage tests are then performed. If the test results are qualified, the test is considered qualified.

[0043] The above provides a comprehensive description of all the functions of this testing system. However, this testing system may include only a positive pressure pipeline testing system to perform positive pressure loss testing and Venturi joint desorption testing of PCV check valves; it may also include a positive pressure pipeline testing system and a shared pipeline system to perform positive pressure loss testing, Venturi joint desorption testing, and positive and negative pulse testing of PCV check valves; it may also include a positive pressure pipeline testing system and a negative pressure pipeline testing system to perform positive pressure loss testing, Venturi joint desorption testing, and leakage testing of PCV check valves; or it may include a positive pressure pipeline testing system, a negative pressure pipeline testing system, and a shared pipeline system to perform positive pressure loss testing, Venturi joint desorption testing, leakage testing, and positive and negative pulse testing of PCV check valves.

[0044] The positive pressure pipeline testing system in this test system is equipped with a large flow meter of 1.5~150L / min and a positive pressure sensor of -1~9bar, while the negative pressure pipeline testing system is equipped with a small flow meter of 0.05~5L / min and a negative pressure sensor of -1~9bar. It also has the testing capabilities for PCV check valves and Venturi connectors.

[0045] When in use, the high-precision components can meet the accuracy requirements of the test, with the mass flow meter measuring accuracy being ±0.5%FS and the pressure sensor measuring accuracy being ±0.5%FS.

[0046] This testing system can be applied to test PCV check valves and venturi fittings in any state. It can also be used to test the performance of PCV check valves and venturi fittings in air filter systems integrating crankcase ventilation valves and carbon canister desorption venturi fittings. When used in air filter systems integrating crankcase ventilation valves and carbon canister desorption venturi fittings, the testing system is connected to the PCV check valve and venturi fitting installed on the air filter system as shown in the attached diagram to achieve the corresponding performance tests.

[0047] This system utilizes modular hardware combinations to perform four tests on engine PCV check valves and carbon canister venturi connectors: positive pressure loss, leakage, positive and negative pressure pulses, and venturi connector desorption. The positive pressure pipeline testing system uses external compressed air, eliminating the need for a separate air compressor and excluding the environmental testing chamber. This results in a compact device with minimal installation space requirements.

[0048] This system can be flexibly assembled with external high and low temperature test chambers to support product performance testing under different temperature conditions.

[0049] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0050] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on these embodiments, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art can still combine, add, delete, or otherwise adjust the features of the various embodiments of the present invention according to the circumstances without conflict or creative effort, thereby obtaining different technical solutions that do not fundamentally depart from the concept of the present invention. These technical solutions also fall within the scope of protection of the present invention.

Claims

1. A test system for PCV check valves and venturi connectors, characterized in that: The system is configured to include a positive pressure pipeline testing system for PCV check valve positive pressure loss testing and Venturi joint desorption testing; The positive pressure pipeline testing system includes a ball valve (1), an air filter (2), a compressed air switch (3), a mist separator (4), an air tank (5), an electric proportional valve (6), a first pneumatic ball valve (8), a first positive pressure sensor (9-1), a second positive pressure sensor (9-2), a positive pressure flow test outlet (10), a positive pressure flow test return port (11), a large-range mass flow meter (12), a first pneumatic control valve (13), a second pneumatic control valve (14), a Venturi suction port (16), and pipelines. An air filter (2), a compressed air switch (3), a mist separator (4), an air tank (5), an electric proportional valve (6), a first pneumatic ball valve (8), a first positive pressure sensor (9-1), and a second positive pressure sensor (9-2) are connected in sequence through pipelines between the ball valve (1) and the positive pressure flow test outlet (10); a second positive pressure sensor (9-2), a large-range mass flow meter (12), and a second pneumatic control valve (14) are connected in sequence through pipelines between the positive pressure flow test return port (11) and the Venturi suction port (16); a first pneumatic control valve (13) is connected to the large-range mass flow meter (12) through a pipeline; During the positive pressure loss test of the PCV check valve, the PCV check valve (15a) under test is connected to the positive pressure flow test outlet (10) and the positive pressure flow test return port (11) through pipelines respectively; During the Venturi joint desorption test, the drive port (15b-1) of the Venturi joint under test (15b) is connected to the positive pressure flow test outlet (10) through a pipeline, and the suction port (15b-2) of the Venturi joint under test (15b) is connected to the Venturi suction port (16) through a pipeline.

2. The test system for PCV check valves and venturi connectors according to claim 1, characterized in that: It is also configured to include a shared piping system, which includes a third positive pressure sensor (27), a solenoid valve (28), a positive and negative pressure alternating test port (29), and piping; The positive pressure pipeline testing system also includes a first positive pressure pneumatic control solenoid valve (7-1) and a second positive pressure pneumatic control solenoid valve (7-2). One end of the first positive pressure pneumatic control solenoid valve (7-1) and the second positive pressure pneumatic control solenoid valve (7-2) are connected to the end of the electric proportional valve (6) and the first pneumatic control ball valve (8) through a pipeline. The other end of the first positive pressure pneumatic control solenoid valve (7-1) and the second positive pressure pneumatic control solenoid valve (7-2) are connected to one end of the third positive pressure sensor (27) through a pipeline. The solenoid valve (28) is located between the other end of the third positive pressure sensor (27) and the positive and negative pressure alternating test port (29), and is connected to the third positive pressure sensor (27) and the positive and negative pressure alternating test port (29) through pipelines respectively. The positive pressure pipeline test system and the shared pipeline system are used together for the positive pulse test of the PCV check valve. During the positive pulse test of the PCV check valve, the positive and negative pressure alternating test port (29) is connected to the PCV check valve (15a) under test through the pipeline.

3. The test system for PCV check valves and venturi fittings according to claim 1 or 2, characterized in that, The pressure range of the first positive pressure sensor (9-1) and the second positive pressure sensor (9-2) is -1 to 9 bar.

4. The test system for PCV check valves and venturi connectors according to claim 1 or 2, characterized in that, The measurement range of the large-range mass flow meter (12) is 1.5~150L / min.

5. A test method for a PCV check valve and a venturi connector, characterized in that, This method is implemented based on the test system described in any one of claims 1-4, including PCV check valve forward pressure loss test and Venturi joint desorption test. During the positive pressure loss test of the PCV check valve, the first pneumatic control valve (13) is open and the second pneumatic control valve (14) is closed. Compressed air passes through the ball valve (1), air filter (2), compressed air switch (3), mist separator (4), air tank (5), electric proportional valve (6), first pneumatic control ball valve (8), first positive pressure sensor (9-1), positive pressure flow test outlet (10), PCV check valve under test (15a), positive pressure flow test return port (11), and second positive pressure sensor (9-1). -2) After the large-range mass flow meter (12) and the first pneumatic control valve (13) are discharged into the outside atmosphere; the pressure readings of the first positive pressure sensor (9-1) and the second positive pressure sensor (9-2) upstream and downstream of the PCV check valve (15a) under test are collected respectively. The two pressure values ​​are subtracted and the result of the subtraction is compared with the standard value of positive pressure loss of PCV check valve. If the result of the subtraction is less than or equal to the standard value of positive pressure loss of PCV check valve, the pressure loss test of PCV check valve (15a) under test is qualified; otherwise, it is unqualified. During the Venturi joint desorption test, the first pneumatic control valve (13) is closed and the second pneumatic control valve (14) is open. Compressed air flows into the drive port (15b-1) of the Venturi joint under test (15b) after passing through the ball valve (1), air filter (2), compressed air switch (3), micro-mist separator (4), air tank (5), electric proportional valve (6), first pneumatic control ball valve (8), first positive pressure sensor (9-1), and positive pressure flow test outlet (10). Atmosphere flows into the suction port (15b-2) of the Venturi joint under test (15b) after passing through the second positive pressure sensor (9-2), large range mass flow meter (12), second pneumatic control valve (14), and Venturi suction port (16). When a specified positive pressure is applied to the drive port (15b-1), the suction port (15b-2) generates a suction force, and the reading of the large-range mass flow meter (12) at this time is the desorbed flow rate.

6. A test method for a PCV check valve and a venturi connector, characterized in that, This method is implemented based on the test system described in claim 2, including PCV check valve forward pressure loss test, Venturi joint desorption test and PCV check valve positive pulse test; During the positive pressure loss test of the PCV check valve, the first pneumatic control valve (13) is open and the second pneumatic control valve (14) is closed. Compressed air passes through the ball valve (1), air filter (2), compressed air switch (3), mist separator (4), air tank (5), electric proportional valve (6), first pneumatic control ball valve (8), first positive pressure sensor (9-1), positive pressure flow test outlet (10), PCV check valve under test (15a), positive pressure flow test return port (11), and second positive pressure sensor (9-1). -2) After the large-range mass flow meter (12) and the first pneumatic control valve (13) are discharged into the outside atmosphere; the pressure readings of the first positive pressure sensor (9-1) and the second positive pressure sensor (9-2) upstream and downstream of the PCV check valve (15a) under test are collected respectively. The two pressure values ​​are subtracted and the result of the subtraction is compared with the standard value of positive pressure loss of PCV check valve. If the result of the subtraction is less than or equal to the standard value of positive pressure loss of PCV check valve, the pressure loss test of PCV check valve (15a) under test is qualified; otherwise, it is unqualified. During the Venturi joint desorption test, the first pneumatic control valve (13) is closed and the second pneumatic control valve (14) is open. Compressed air flows into the drive port (15b-1) of the Venturi joint under test (15b) after passing through the ball valve (1), air filter (2), compressed air switch (3), micro-mist separator (4), air tank (5), electric proportional valve (6), first pneumatic control ball valve (8), first positive pressure sensor (9-1), and positive pressure flow test outlet (10). Atmosphere flows into the suction port (15b-2) of the Venturi joint under test (15b) after passing through the second positive pressure sensor (9-2), large range mass flow meter (12), second pneumatic control valve (14), and Venturi suction port (16). When a specified positive pressure is applied to the drive port (15b-1), the suction port (15b-2) generates a suction force, and the reading of the large-range mass flow meter (12) at this time is the desorbed flow rate. During the positive pulse test of the PCV check valve, a positive pressure pulse is provided to the PCV check valve (15a) under test. In this test state, the first pneumatic ball valve (8) is closed, and the first positive pressure pneumatic solenoid valve (7-1) and the second positive pressure pneumatic solenoid valve (7-2) are open. Compressed air flows through the ball valve (1), air filter (2), compressed air switch (3), mist separator (4), air tank (5), electric proportional valve (6), first positive pressure pneumatic solenoid valve (7-1), second positive pressure pneumatic solenoid valve (7-2), third positive pressure sensor (27), solenoid valve (28), positive and negative pressure alternating test port (29) and the PCV check valve (15a) under test before being discharged into the outside atmosphere.

7. The application of the test system for PCV check valves and venturi joints as described in any one of claims 1-5 in an air filter system integrating a crankcase forced ventilation valve and a carbon canister desorption venturi joint.

Images