An EGR valve internal waterproof sealing performance testing device

Abstract

An EGR valve internal waterproof sealing performance testing device includes: a heating device for heating water in the inner cavity of the EGR valve's exhaust gas passage to the temperature required for vaporization; a pressurizing device connected to the exhaust gas passage for applying air pressure to the inner cavity of the exhaust gas passage; a sealing device for sealing the opening of the exhaust gas passage; an observation plate, which is sealed and installed on the front side of the valve body's drive chamber for observing the liquefaction of water vapor; and a cooling device for cooling the observation plate to the temperature required for water vapor liquefaction. This device is suitable for testing the waterproof sealing performance of sealing structures composed of valve plugs, O-rings, and sealing rings of different materials and sizes. It allows for testing and analysis of the waterproof sealing performance of sealing structures during the development stage of sealing components and before durability testing, facilitating performance comparison and selection of key sub-components of the EGR valve during the development stage.

Description

Technical Field

[0001] This utility model relates to the technical field of diesel engine exhaust gas recirculation systems, and in particular to a device for testing the internal waterproof sealing performance of an EGR valve. Background Technology

[0002] The function of an exhaust gas recirculation (EGR) system is to reintroduce exhaust gases from the engine into the intake system, mix them with fresh air, and then enter the cylinders to participate in the combustion process again. It is a vehicle exhaust purification device designed to target nitrogen oxides (NOx), one of the harmful gases in engine exhaust. Exhaust gas recirculation (EGR) is primarily used to reduce NOx emissions. x The emission of NO is reduced by increasing the proportion of high-specific-heat-capacity gases such as CO2 in the combustible mixture, thereby decreasing the combustion rate and increasing the specific heat capacity of the mixture, thus lowering the maximum combustion temperature. Simultaneously, the introduction of exhaust gases reduces the oxygen content in the mixture. Since high temperature and oxygen enrichment are conducive to NO combustion... x Therefore, by reducing the combustion temperature and oxygen content ratio, the exhaust gas recirculation system can effectively suppress NO formation. x The generation of .

[0003] The fuel used in engines is composed of hydrocarbons, and diesel fuel is a mixture of different types of hydrocarbons. Theoretically, when hydrocarbon molecules are completely burned, only CO2 and H2O are formed. The chemical reaction of fuel under complete combustion conditions can be represented as: C x H y +(x+y / 2)O2→xCO2+y / 2H2O, therefore the exhaust gas from a diesel engine contains NO. x In addition to HC compounds and PM particulate matter, the exhaust gas also contains water vapor produced by combustion. Before passing through the EGR cooler, the water vapor in the exhaust gas exists in gaseous form due to the high exhaust temperature. After being cooled by the cooler, a large amount of liquid condensate will precipitate due to the decrease in temperature. The condensate reaches the inside of the EGR valve through the exhaust gas recirculation pipe.

[0004] like Figure 1 As shown in the figure, during the opening / closing process of the EGR valve body 1, the exhaust gas in the exhaust gas passage 2 contains a large amount of water vapor. The valve stem 3 will move back and forth to open and close the valve 4. Since the engine exhaust gas is a high-pressure gas, the high-pressure water vapor will enter the drive chamber 8 through the sealing structure composed of O-ring 5, sealing ring 6, and valve plug 7, causing low-temperature freezing, corrosion, or failure of the drive motor and position sensor (not shown) inside the drive chamber 8.

[0005] There is currently no consistent testing standard in the industry for assessing how much condensate or water vapor seeps into the drive chamber 8 and the drive motor through the sealing structure. When developing the sealing structure of EGR valves, most suppliers mainly rely on the reliability and durability tests and low-temperature tests of the EGR valve to assess whether the sealing structure's ability to seal against condensate meets the requirements. However, durability tests are time-consuming and costly. Relying on durability tests or low-temperature tests to assess the sealing structure's ability to seal against condensate will inevitably lead to a waste of time and material resources. Utility Model Content

[0006] In view of this, it is necessary to provide a testing device for qualitatively testing the waterproof performance of the internal sealing structure of an EGR valve.

[0007] An EGR valve internal waterproof sealing performance testing device, comprising:

[0008] A heating device is used to heat the water inside the exhaust gas passage of the EGR valve to the temperature required for vaporization.

[0009] A pressurizing device, which is connected to the exhaust gas passage, is used to apply air pressure to the inner cavity of the exhaust gas passage;

[0010] A sealing device for sealing the opening of the exhaust gas passage;

[0011] An observation plate is installed in a sealed manner on the front side of the drive chamber of the valve body to observe the liquefaction of water vapor.

[0012] A cooling device is used to cool the observation plate to the temperature required for water vapor liquefaction.

[0013] Furthermore, the pressurizing device includes a pressurizing flange, which is detachably fixed to the outside of the first opening of the exhaust gas passage, and the pressurizing flange is connected to a pressurizing pipe.

[0014] Furthermore, the sealing device includes a fixing plate, which is detachably fixed to the outside of the second and third openings of the exhaust gas passage.

[0015] Furthermore, the heating device includes a heating plate, and the valve body is placed on the heating plate via a fixing plate.

[0016] Furthermore, the observation plate is a transparent PC plate, which is detachably fixed to the outside of the drive chamber opening of the valve body.

[0017] Furthermore, a first gasket is sandwiched between the fixing plate and the second opening, and between the fixing plate and the third opening, and a second gasket is sandwiched between the transparent PC plate and the drive cavity opening.

[0018] Furthermore, a first thermocouple is sandwiched between the fixing plate and the first gasket, and a second thermocouple is sandwiched between the transparent PC plate and the second gasket.

[0019] Furthermore, the cooling device includes a fan positioned directly opposite the observation panel.

[0020] This utility model device can be used to test the waterproof sealing performance of sealing structures composed of valve plugs, O-rings, and sealing rings of different materials and sizes. It can test and analyze the waterproof sealing performance of sealing structures during the development stage of sealing parts and before the start of durability testing, which helps to compare and select the performance of key sub-components of EGR valves during the development stage. The device is simple and easy to use, and the test results are intuitive. The differences in sealing and waterproof performance between different sealing structures can be easily compared and judged by the human eye. Attached Figure Description

[0021] Figure 1 This is a cross-sectional view of the valve body in an existing EGR valve.

[0022] Figure 2 This is a schematic diagram of the internal waterproof sealing performance testing device for the EGR valve of this utility model.

[0023] Figure 3 for Figure 2 Cross-sectional view of the internal waterproof sealing performance testing device for the EGR valve.

[0024] Figure 4 for Figure 2 A flowchart illustrating the usage of the testing device for the internal waterproof sealing performance of the EGR valve. Detailed Implementation

[0025] To facilitate understanding of this utility model, a more complete description will be given below with reference to the accompanying drawings. Several embodiments of this utility model are shown in the drawings. However, this utility model can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this utility model will be more thorough and complete.

[0026] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0028] like Figure 2 and Figure 3 As shown, the EGR valve internal waterproof sealing performance testing device in the first embodiment of this utility model includes:

[0029] Heating device for heating the water in the inner cavity of the EGR valve exhaust gas passage 2 to the temperature required for vaporization;

[0030] A pressurizing device, which is connected to the exhaust gas passage 2, is used to apply air pressure to the inner cavity of the exhaust gas passage 2;

[0031] A sealing device for sealing the opening of the exhaust gas passage 2;

[0032] An observation plate is installed in a sealed manner on the front side of the drive chamber 8 of the valve body 1 to observe the liquefaction of water vapor.

[0033] A cooling device is used to cool the observation plate to the temperature required for water vapor liquefaction.

[0034] In this embodiment, the pressurizing device includes a pressurizing flange 10, which is detachably fixed to the outside of the first opening 11 of the exhaust gas passage 2 by bolts. The pressurizing flange 10 is connected to a pressurizing pipe 12, through which a certain air pressure is applied to the inner cavity of the valve body 1.

[0035] The sealing device includes a fixing plate 13, which is fixedly installed on the outside of the second opening 14 and the third opening 15 of the exhaust gas passage 2 by bolts, and a first gasket is sandwiched between the fixing plate 13 and the opening of the exhaust gas passage 2 to improve the sealing performance of the fixing plate 13 to the opening of the exhaust gas passage 2.

[0036] The heating device includes a heating plate 9, specifically a digital ceramic heating plate, which can set the heating temperature and has a digital temperature display function; the valve body 1 is stably placed on the heating plate 9 through a fixing plate 13, and the heating plate 9 heats the valve body 1 through the fixing plate 13 by heat conduction.

[0037] The observation plate is specifically a transparent PC plate 16. The transparent PC plate 16 is bolted to the outside of the opening of the drive cavity 8 of the valve body 1, and a second gasket is sandwiched between the transparent PC plate 16 and the opening of the drive cavity 8 to improve the sealing performance of the transparent PC plate 16 to the opening of the drive cavity 8.

[0038] The cooling device includes a fan 17, which faces the opening of the transparent PC board 16 and the drive cavity 8 to blow air and cool the transparent PC board 16.

[0039] In use, the valve 4 is fixed in the open position by adjusting the valve stem 3 inside the valve body 1. The pressure flange 10 is removed, and a certain amount of distilled water is injected into the inner cavity of the exhaust gas passage 2 of the valve body 1 through the first opening 11. The pressure flange 10 is then installed, and a certain air pressure is applied to the inside of the exhaust gas passage 2 through the pressure pipe 12. It is checked whether there is any leakage at each gasket. If there is no leakage, the air pressure is stopped. In specific use, the exhaust hole of the drive cavity 8 should also be blocked, depending on the specific model and structure of the valve body 1. The switch of the heating plate 9 is turned on, and the heating plate 9 is set to a certain temperature to heat the valve body 1, so that the distilled water in the inner cavity of the exhaust gas passage 2 is vaporized into water vapor. The fan 17 is kept at a stable speed to blow air onto the transparent PC board 16 to cool it down. Pressurization is applied again through pressurization pipe 12 and measurement begins. Under high pressure, water vapor leaks into drive chamber 8 through O-ring 5, sealing ring 6 and valve plug 7 in sequence, and condenses on transparent PC plate 16 with a relatively low temperature outside the opening of drive chamber 8. The condensation of water droplets on transparent PC plate 16 is continuously observed or photographed at regular intervals.

[0040] In this embodiment, a first thermocouple 18 is also clamped between the fixing plate 13 and the first gasket, for real-time monitoring of the water temperature inside the exhaust gas channel 2 to ensure that the water temperature meets the requirements for vaporization under high pressure. In specific use, after the heating plate 9 starts heating, when the first thermocouple 18 detects that the water temperature has reached a suitable temperature, air pressure can be applied for measurement. A second thermocouple 19 is also clamped between the transparent PC plate 16 and the second gasket, for real-time monitoring of the temperature of the transparent PC plate 16 to ensure that the temperature conditions of the transparent PC plate 16 meet the requirements for water vapor liquefaction.

[0041] like Figure 4 As shown, when using the EGR valve internal waterproof sealing performance testing device described in the first embodiment of this utility model, the method includes the following specific steps:

[0042] S1. Fix valve 4 inside the EGR valve body 1 in the open state, inject a calibrated volume of distilled water into the inner cavity of the exhaust gas passage 2, and seal the inner cavity of the exhaust gas passage 2.

[0043] S2. Set the heating device to the first calibrated temperature and use the cooling device to cool the observation plate.

[0044] S3. When the distilled water is heated to the second calibration temperature, the calibration pressure is applied to the inner cavity of the exhaust gas channel 2 through the pressurization device, and the measurement begins.

[0045] S4. Continuously observe or photograph the water droplet condensation on the transparent PC board 16 at the calibrated time.

[0046] In this embodiment, the calibration volume is 60 ml, the first calibration temperature is 200°C, the second calibration temperature is 70°C, the calibration pressure is 200 kPa, and the calibration time is 0 minutes, 2 minutes, 6 minutes, and 10 minutes.

[0047] Furthermore, to ensure the airtightness of the inner cavity of the exhaust gas passage 2, after step S1, a calibrated air pressure is applied to the inner cavity of the exhaust gas passage 2 using a pressurizing device to confirm whether there is any water leakage at each opening of the valve body 1. If there is no water leakage, the air pressure is stopped. In specific operation, depending on the specific model and structure of the valve body 1, the exhaust port of the drive chamber 8 should also be blocked.

[0048] This utility model device can be used to test the waterproof sealing performance of sealing structures composed of valve plugs, O-rings, and sealing rings of different materials and sizes, such as the two different sealing structures in this test example:

[0049] The valve plug of sealing structure one is made of SUS304L, the sealing ring is made of PTFE, and the O-ring is made of silicone rubber; the valve plug of sealing structure two is made of SUS304L, the sealing ring is made of PTFE+SUS340, and the O-ring is made of fluororubber.

[0050] Using the aforementioned EGR valve internal waterproof sealing performance testing device, sealing structure one condensed a large amount of water droplets on the transparent PC plate after 6 minutes, while sealing structure two still did not show obvious water droplet condensation after 10 minutes. Therefore, the waterproof performance of the constituent materials of sealing structure two is better than that of sealing structure one.

[0051] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0052] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A device for testing the internal waterproof sealing performance of an EGR valve, characterized in that: include: A heating device is used to heat the water inside the exhaust gas passage of the EGR valve to the temperature required for vaporization. A pressurizing device, which is connected to the exhaust gas passage, is used to apply air pressure to the inner cavity of the exhaust gas passage; A sealing device for sealing the opening of the exhaust gas passage; An observation plate is installed in a sealed manner on the front side of the drive chamber of the valve body to observe the liquefaction of water vapor. A cooling device is used to cool the observation plate to the temperature required for water vapor liquefaction.

2. The EGR valve internal waterproof sealing performance testing device according to claim 1, characterized in that: The pressurizing device includes a pressurizing flange, which is detachably fixed to the outside of the first opening of the exhaust gas passage, and the pressurizing flange is connected to a pressurizing pipe.

3. The EGR valve internal waterproof sealing performance testing device according to claim 1, characterized in that: The sealing device includes a fixing plate, which is detachably fixed to the outside of the second and third openings of the exhaust gas passage.

4. The EGR valve internal waterproof sealing performance testing device according to claim 3, characterized in that: The heating device includes a heating plate, and the valve body is placed on the heating plate via a fixing plate.

5. The EGR valve internal waterproof sealing performance testing device according to claim 3, characterized in that: The observation plate is a transparent PC plate, which is detachably and fixedly connected to the outside of the drive chamber opening of the valve body.

6. The EGR valve internal waterproof sealing performance testing device according to claim 5, characterized in that: A first gasket is sandwiched between the fixing plate and the second opening, and between the fixing plate and the third opening; a second gasket is sandwiched between the transparent PC plate and the drive cavity opening.

7. The EGR valve internal waterproof sealing performance testing device according to claim 6, characterized in that: A first thermocouple is sandwiched between the fixing plate and the first gasket, and a second thermocouple is sandwiched between the transparent PC plate and the second gasket.

8. The EGR valve internal waterproof sealing performance testing device according to claim 1, characterized in that: The cooling device includes a fan that faces the observation panel.

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