Multifunctional sealing element testing device and testing method thereof

Abstract

The invention provides a multifunctional sealing element test device and a test method thereof. The device comprises a pressure test chamber and a safety monitoring pressure relief assembly, the pressure test chamber comprises an upper die holder and a lower die holder which are detachably clamped, the lower die holder is integrally formed with a medium cavity and is filled with a liquid or gas test medium, and a to-be-tested sealing ring is placed in a sealing groove in the periphery of the cavity; an air inlet and an air outlet in the upper portion of the medium cavity are sequentially connected with a first pipe connector, a copper pipe, a second pipe connector, a first valve block, a third pipe connector and a second valve block, a pressure gauge and a pressure sensor are arranged on the top of the first valve block, the lateral ball valve is a first-stage pressure relief opening, the second valve block is provided with a thermometer and a temperature sensor, and the ball valve on the other side forms a second-stage pressure relief opening. Therefore, temperature-pressure dual-redundancy monitoring and graded pressure relief are realized. The device is compact in structure and easy and convenient to assemble and disassemble, high-temperature corrosive medium and high-pressure coupling loading can be completed in a single platform, data can be collected in real time, and the safety and efficiency of reliability evaluation of the sealing element are remarkably improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of reliability testing of seals, and particularly relates to a multi-functional seal test device and a test method thereof. Background Art

[0002] Seals are widely used in industries such as aerospace, automotive, petrochemical, and high-end manufacturing. Their long-term service environment often involves coupled loads such as alternating pressure, temperature shock, and chemical medium corrosion. With the continuous improvement of the airtightness level of equipment, the traditional evaluation method of single-factor segmented testing has become difficult to accurately characterize the failure mechanism of seals during their entire life cycle.

[0003] The existing common practice is to first conduct aging treatment in an incubator or an oil bath device, then transfer the specimen to a static pressure fixture for a pressure resistance test, or only conduct a constant pressure and temperature test in an autoclave. There are three deficiencies in such a scheme: First, the test process is split into multiple links, and the specimen is prone to deformation or contamination during transportation, disassembly, and assembly, resulting in inconsistent aging states and pressure resistance working conditions, thereby reducing the credibility of the data. Second, most devices can only apply a constant pressure or constant temperature in one direction, and cannot simulate the dynamic coupling effect of pressure-temperature-medium under real working conditions, nor can they capture the transient signals at the initial stage of leakage. Third, the safety protection and data acquisition means are backward. Once the temperature or pressure suddenly changes, the operator relies on manual pressure relief, which poses a risk of explosion. At the same time, usually only a single pressure sensor and a thermocouple are arranged in the medium cavity, lacking real-time multi-dimensional data and failure video records.

[0004] With the development of sealing materials towards polymer composites and test media towards high corrosiveness and high volatility, higher requirements are put forward for the sealing reliability, rapid pressure relief ability, and sensing redundancy of the test device.

[0005] Therefore, there is still a need to provide a general seal test device and its supporting test method that are structurally compact, safe and reliable, can achieve synchronous loading of multiple factors within a single platform, and can collect multi-modal data in real time to make up for the deficiencies of the existing technology. Summary of the Invention

[0006] The present invention provides a multi-functional seal test device and a test method thereof, and the technical problem to be solved is how to synchronously implement the high-pressure, temperature, and medium corrosion coupling tests of the seal within a single device, and ensure operation safety and real-time data collection.

[0007] To achieve the above object, the technical solution of the present invention is as follows:

[0008] In the first aspect, the present invention provides a multi-functional seal test device, including a pressure test chamber and a safety monitoring and pressure relief assembly;

[0009] The pressure test chamber includes an upper die holder and a lower die holder that are detachably clamped and connected. A test cavity is formed between the upper die holder and the lower die holder. A medium cavity is provided at the lower end of the lower die holder. The medium cavity is integrally cast with the lower die holder. A test medium is injected into the medium cavity, and the medium cavity is communicated with the test cavity. A sealing groove is provided at the peripheral edge of the upper end surface of the lower die holder, and a sealing ring to be tested is arranged in the sealing groove. An air inlet and exhaust port is provided at the upper part of the medium cavity, and the air inlet and exhaust port is connected to the safety monitoring and pressure relief assembly.

[0010] The safety monitoring and pressure relief assembly includes a first pipe joint, a copper pipe, a second pipe joint, a first valve block, a third pipe joint, and a second valve block connected to the air inlet and exhaust port. A pressure gauge is installed on the top of the first valve block, and a pressure sensor is arranged at the same port. A ball valve is provided at the lateral through port of the first valve block. The lower end of the third pipe joint is communicated with the second valve block. A thermometer is installed at the lower side port of the second valve block, and a temperature sensor is arranged at the same port. A ball valve is provided on the other side of the second valve block.

[0011] Further, a curved guiding boss protrudes downward from the center of the bottom surface of the upper die holder, and a guiding groove matching the curved guiding boss is provided on the lower die holder.

[0012] Further, a corrosion-resistant coating is provided on the inner wall of the medium cavity.

[0013] Further, the upper die holder and the lower die holder are detachably clamped and connected by a plurality of uniformly distributed bolts.

[0014] Further, an electric heating jacket is arranged on the outer periphery of the upper die holder.

[0015] Further, the test medium is a liquid or a gas.

[0016] Further, the interiors of the first valve block and the second valve block are both of a cross-shaped flow channel structure, and the pressure gauge and the pressure sensor, and the thermometer and the temperature sensor are respectively communicated with the side branches of the cross-shaped flow channel.

[0017] Further, the third pipe joint between the first valve block and the second valve block is a rigid connecting pipe arranged vertically.

[0018] Further, the pressure sensor is an electronic pressure transmitter with a measuring range of 0–10 MPa and an accuracy of not less than 0.25% FS.

[0019] In a second aspect, the present invention provides a multifunctional seal test method, including the following steps:

[0020] a) Place the sealing ring to be tested into the sealing groove of the lower die base, close the upper die base and the lower die base and clamp them with bolts, so that the arc-shaped guiding boss of the upper die base cooperates with the guiding groove of the lower die base to complete coaxial positioning;

[0021] b) Inject a predetermined volume of test medium into the medium cavity through the air inlet and exhaust port, and open the first-stage ball valve of the safety monitoring and pressure relief component to exhaust air, so that the test medium fills the medium cavity and the test cavity in sequence. After the pressure gauge indicates zero, close the first-stage ball valve to complete the exhaust;

[0022] c) Start the electric heating jacket on the outer periphery of the upper die base, raise the temperature of the test cavity to the set aging temperature T1, and keep it at a constant temperature for a predetermined aging time t1 to complete the accelerated aging test of the sealing ring;

[0023] d) After the aging is completed, stop heating and stabilize to the set test temperature T2. Then, gradually increase the pressure in the medium cavity to the target pressure P1 through the safety monitoring and pressure relief component, and use the pressure gauge and pressure sensor on the first valve block for real-time monitoring, and maintain it at this pressure for a predetermined pressure holding time t2;

[0024] e) During the whole processes of step c) and step d), the thermometer and the temperature sensor record the temperature data in real time, and the pressure sensor records the pressure data in real time. If the detected pressure or temperature exceeds the preset threshold, the corresponding ball valve is automatically or manually opened for pressure relief;

[0025] f) After the pressure holding is completed, slowly reduce the pressure and temperature, discharge the test medium, disassemble the upper die base, take out the sealing ring, and evaluate its leakage amount, deformation amount and surface state to obtain the comprehensive test result.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] In the present invention, the integrated medium cavity and the lower die base are integrally cast, reducing the possible leakage channels at the traditional threaded joints; a fluororubber O-ring is embedded in the sealing groove, which can maintain elasticity and resilience in high-temperature and various chemical medium environments, ensuring long-term reliable sealing of the cavity; the exhaust passage is sequentially provided with a copper pipe, two-stage valve blocks and ball valves, forming a three-level protection chain of "monitoring, slow release, and cut-off": the pressure gauge and the pressure sensor are compared in real time, and when an abnormality occurs, the pressure relief hole built in the valve block is triggered to release pressure first. If the pressure continues to rise, the ball valve automatically cuts off the pressure source and opens the bypass pressure relief port, minimizing the threat of sudden pressure to the cavity structure and operators; the inner wall of the cavity is sprayed with a corrosion-resistant coating, which can effectively isolate the erosion of highly volatile or highly corrosive media such as diesel and aviation fuel on the metal matrix, extending the service life of the device; an external optional electric heating jacket is provided, significantly improving the temperature control and heating uniformity, and avoiding the distortion of the sealing performance caused by local overheating.

[0028] At the test method level, through the closed-loop process of "injecting medium - boosting pressure - raising temperature - cyclic loading - real-time acquisition - automatic pressure relief", the present invention locks the multi-factor test steps such as aging, pressure resistance, and dynamic fatigue in the same cavity and completes them continuously. First, a set volume of corrosive medium is injected, and then the gas-liquid booster pump boosts the pressure at an adjustable rate, which can simulate the sealed environment of the equipment under different depths and pressure conditions. Subsequently, the electric heating jacket heats up and maintains a constant temperature according to a preset gradient, causing the temperature and pressure to rise synchronously, truly restoring the coupled stress field during the service process of the seal. During the whole test, pressure and temperature data are collected and the start time of leakage is recorded. Combining with the automatic pressure relief logic, the failure threshold can be captured and the test can be terminated without manual intervention, which not only improves the data continuity but also ensures the operation safety.

[0029] Of course, it is not necessary for each technical solution of the present invention to achieve all the above-mentioned advantages simultaneously. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0031] Figure 1 is a schematic three-dimensional structure diagram of the multi-functional seal test device according to the embodiment of the present invention;

[0032] Figure 2 is a top view schematic diagram of the multi-functional seal test device according to the embodiment of the present invention.

[0033] In the figure, 1 - upper die holder, 2 - lower die holder, 3 - test medium, 4 - seal groove, 5 - exhaust port, 6 - medium cavity, 7 - first pipe joint, 8 - copper pipe, 9 - second pipe joint, 10 - thermometer, 11 - temperature sensor, 12 - first valve block, 13 - pressure gauge, 14 - pressure sensor, 15 - ball valve, 16 - second valve block, 17 - bolt, 18 - third pipe joint. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] To facilitate the understanding of the present invention, the present invention will be described more comprehensively with reference to the relevant drawings. The preferred embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present invention more thorough and comprehensive.

[0035] In the description of this patent, it should be understood that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing this patent and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to this patent.

[0036] In the description of this patent, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", "joined", "set" should be understood in a broad sense. For example, it can be fixedly connected and set, or detachably connected and set, or integrally connected and set. For those of ordinary skill in the art, the specific meanings of the above terms in this patent can be understood according to specific circumstances. The following will describe the present invention in detail with reference to the drawings and embodiments.

[0037] Embodiment 1:

[0038] See Figure 1 And Figure 2 The multi-functional seal test device is integrally installed in the rigid metal frame support. The upper die base 1 is integrally formed by CNC machining of high-strength aluminum alloy, and an annular step is provided on the outer periphery for installing a stainless steel electric heating jacket. The strip-shaped resistance wire is compounded with mica insulating sheets and then covered with a heat-insulating layer, which can evenly heat the surface of the upper die base to about 180 °C in a short time.

[0039] An arc-shaped guiding boss is formed at the center of the bottom surface of the upper die base, which cooperates with the guiding groove of the lower die base 2 during the clamping process to achieve rough positioning and improve coaxiality. The lower die base 2 is integrally cast from quenched and tempered carbon steel and then precision milled. An annular sealing groove 4 is provided on the peripheral edge of the upper end surface, and a fluororubber O-ring is pre-installed in the groove to ensure the sealing reliability under high-temperature and high-pressure environments.

[0040] The lower die base is integrally formed with the medium cavity 6. The wall thickness of the cavity is thickened and the inner wall is sprayed with a polytetrafluoroethylene coating and then precision polished to a lower roughness to enhance the resistance to medium corrosion and facilitate cleaning; a threaded air inlet and outlet 5 is opened at the top of the cavity for connecting the safety monitoring and pressure relief assembly.

[0041] The safety monitoring and pressure relief assembly includes, in sequence from the exhaust port 5, a pipe joint 7, a buffer copper pipe 8, a pipe joint 9, a first valve block 12, a vertically arranged pipe joint 18, and a second valve block 16. Both valve blocks are made of stainless steel and are provided with a cross-shaped main flow channel and side branches. A mechanical pressure gauge 13 and an electronic pressure sensor 14 are connected in parallel at the top of the first valve block to achieve dual-redundancy pressure monitoring, and the ball valve 15 at its lateral through port serves as a primary pressure relief port. An oil-filled thermometer 10 and a thermocouple temperature sensor 11 are installed at the lower side port of the second valve block and share a temperature measurement cavity to reduce measurement lag and improve temperature accuracy. A ball valve 15 of the same specification as the first valve block is provided on the other side as a secondary pressure relief port. The buffer copper pipe is bent into a U-shaped buffer section to absorb thermal expansion and contraction and vibration. Each pipe joint is a high-pressure quick-thread connection, and the pressure resistance level meets the test requirements. The upper and lower die bases are detachably clamped by symmetrically arranged high-strength bolts 17 and still maintain reliable stiffness and sealing performance within the working pressure range.

[0042] The signals of the electronic pressure sensor and the temperature sensor are uploaded to the host computer in real time through the reserved DC power supply and bus interface. When the pressure or temperature exceeds the set threshold, the control logic first slightly opens the primary ball valve for pressure relief. If it continues to exceed the limit, the secondary ball valve is quickly opened, forming a three-level safety chain of "monitoring - slow release - cut-off" to improve the test safety and data integrity.

[0043] The multi-functional seal test device of this embodiment can be widely applied to the seal test and evaluation fields such as aerospace, automotive, and petrochemical industries. In the structural design of this device, efficient heat equalization, electro-hydraulic dual-redundancy monitoring, and hierarchical rapid pressure relief are integrated. It not only ensures the long-term seal reliability under the coupling loading of high pressure - high temperature - corrosive medium, but also reduces the maintenance difficulty through modular valve blocks and quick connectors. The actual measurement shows that its pressure relief response time is less than 0.3 s, the temperature uniformity is better than ±2 °C, and the pressure resistance limit is higher than 10 MPa, and the comprehensive performance is significantly improved compared with the traditional split test fixture.

[0044] Embodiment 2:

[0045] The aging - pressure resistance comprehensive test of a fluororubber O-ring is carried out by using the device of Embodiment 1. The test process is as follows:

[0046] S1. At the beginning of the test, place a clean and dry O-ring into the sealing groove 4, close the upper die base 1 and the lower die base 2, and tighten the bolts 17 diagonally. After the guiding boss and the groove are matched to complete coaxial positioning, a test cavity is formed.

[0047] S2. Slowly inject a predetermined volume of denatured diesel into the medium cavity 6 through the air inlet and outlet 5. Open the primary ball valve 15 to exhaust until the pressure gauge 13 returns to zero. The medium fills the medium cavity and the test cavity in sequence, and then close the primary ball valve 15 to complete the exhaust.

[0048] S3. Start the electric heating jacket, at about 4 °C·min-1 Heat up to the set aging temperature of 150°C at a certain rate and keep it constant for 2 hours; the thermometer 10 and the thermocouple 11 sample every 5 seconds and upload the data to the host computer, and the measured fluctuation is kept within ±1°C.

[0049] S4. After the aging is completed, wait for the temperature to naturally drop to 90°C, keep the exhaust passage closed, connect the gas-liquid booster pump, and increase the pressure to the target pressure of 4 MPa at a rate of about 0.03 MPa·s -1 and keep it for 1 hour, and the pressure gauge 13 and the pressure sensor 14 monitor the pressure change in a dual-channel manner.

[0050] S5. If the pressure exceeds 4.2 MPa or the temperature exceeds 95°C, the control system immediately slightly opens the first-stage ball valve 15 to relieve the pressure slowly. If it still exceeds the limit, the second-stage ball valve 15 is fully opened to quickly relieve the pressure, avoiding the out-of-control damage of the seal.

[0051] S6. After the test is completed, slowly reduce the pressure to atmospheric pressure and drain the medium. Remove the upper mold base 1 and take out the O-ring. After the leakage test, the leakage rate is less than 1×10-3 mL·min -1 , the cross-sectional compression permanent deformation rate is about 7%, and no cracks are generated.

[0052] This method continuously completes 150°C heat-medium aging and 4 MPa pressure holding in a single cavity, shortening the test cycle by about one-third compared with the traditional oil bath-hydrostatic pressure segmented process; the 5-second cycle data acquisition during the whole process of heating and pressurizing provides a high-resolution sample for subsequent life modeling. The hierarchical pressure relief strategy effectively suppresses the risk of O-ring bursting in case of instantaneous overpressure, verifying the fast response and safety protection capabilities of the device-method combination under complex coupled loads.

[0053] The above uses specific examples to elaborate on the present invention, which is only used to help understand the present invention and is not intended to limit the present invention. For those skilled in the technical field to which the present invention belongs, according to the idea of the present invention, several simple deductions, deformations or substitutions can also be made.

Claims

1. Multifunctional seal test device, characterized in that, Includes pressure test chamber and safety monitoring pressure relief assembly; The pressure test chamber comprises an upper die base (1) and a lower die base (2) which are detachably clamped and connected, and a test cavity is formed between the upper die base (1) and the lower die base (2); a medium cavity (6) is provided at the lower end of the lower die base (2), and the medium cavity (6) and the lower die base (2) are cast in one body, and a test medium (3) is injected into the medium cavity (6), and the medium cavity (6) and the test cavity are communicated; a sealing groove (4) is provided on the periphery of the upper end surface of the lower die base (2), and a sealing ring to be tested is provided in the sealing groove (4); an air inlet and exhaust port (5) is provided on the upper part of the medium cavity (6), and the air inlet and exhaust port (5) is connected to the safety monitoring pressure relief assembly; The safety monitoring pressure relief assembly comprises a first pipe joint (7) connected to the air inlet and exhaust port (5), a copper tube (8), a second pipe joint (9), a first valve block (12), a third pipe joint (18) and a second valve block (16); a pressure gauge (13) is installed on the top of the first valve block (12), and a pressure sensor (14) is provided at the same port; a ball valve (15) is provided at the side opening of the first valve block (12); the lower end of the third pipe joint (18) is communicated with the second valve block (16), a temperature gauge (10) is installed at the side lower port of the second valve block (16), and a temperature sensor (11) is provided at the same port; a ball valve (15) is provided on the other side of the second valve block (16).

2. The multifunctional seal test device according to claim 1, characterized in that An arc-shaped guide boss is protruding downwardly from the center of the bottom surface of the upper die seat (1), and a guide groove matching the arc-shaped guide boss is provided on the lower die seat (2).

3. The multifunctional seal testing device according to claim 1, characterized in that: The inner wall of the medium cavity (6) is provided with a corrosion-resistant coating.

4. The multifunctional seal test device according to claim 1, characterized in that, The upper die base (1) and the lower die base (2) are detachably clamped and connected via a plurality of evenly distributed bolts (17).

5. The multifunctional seal test device according to claim 1, wherein, An electric heating jacket is provided on the outer periphery of the upper die seat (1).

6. The multifunctional seal test device according to claim 1, characterized in that, The test medium (3) is liquid or gas.

7. The multifunctional seal testing device according to claim 1, characterized in that: The interiors of the first valve block (12) and the second valve block (16) are both cross-shaped flow channel structures, and the pressure gauge (13) and the pressure sensor (14), and the temperature gauge (10) and the temperature sensor (11) are respectively connected to the side branches of the cross-shaped flow channel.

8. The multifunctional seal testing device according to claim 7, characterized in that: The third pipe joint (18) between the first valve block (12) and the second valve block (16) is a vertically arranged rigid connecting pipe.

9. The multifunctional seal test device according to claim 1, characterized in that The pressure sensor (14) is an electronic pressure transmitter with a measuring range of 0-10 MPa and an accuracy of not less than 0.25% FS.

10. Multifunctional seal test method, characterized in that: The following steps are involved: a) Place the sealing ring to be tested into the sealing groove (4) of the lower die base (2), close the upper die base (1) and the lower die base (2) and clamp them with bolts (17) so that the arc-shaped guide boss of the upper die base (1) and the guide groove of the lower die base (2) cooperate to complete coaxial positioning; b) injecting a predetermined volume of test medium (3) into the medium cavity (6) through the air inlet and outlet port (5), and opening the first-level ball valve (15) of the safety monitoring pressure relief assembly to exhaust the test medium, so that the test medium fills the medium cavity (6) and the test cavity in turn, and closing the first-level ball valve (15) to complete the exhaust after the pressure gauge (13) indicates zero; c) Start the electric heating jacket on the periphery of the upper die base (1), raise the temperature of the test cavity to the set aging temperature T1, and maintain the constant temperature for the predetermined aging time t1 to complete the accelerated aging test of the sealing ring; d. After the aging is completed, the heating is stopped and the temperature is stabilized to the set test temperature T2. Then, the pressure in the medium cavity (6) is gradually increased to the target pressure P1 through the safety monitoring pressure relief component. The pressure gauge (13) and the pressure sensor (14) on the first valve block (12) are used for real-time monitoring. The pressure is maintained at this pressure for a predetermined pressure resistance time t2; e) During the entire process of step c) and step d), the temperature meter (10) and the temperature sensor (11) record the temperature data in real time, and the pressure sensor (14) records the pressure data in real time. If it is detected that the pressure or temperature exceeds a preset threshold, the corresponding ball valve (15) is automatically or manually opened to release the pressure; f) After the pressure resistance is maintained, the pressure and temperature are slowly reduced, the test medium (3) is discharged, the upper die seat (1) is disassembled, the sealing ring is taken out, and its leakage, deformation and surface condition are evaluated to obtain a comprehensive test result.

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