Experimental device suitable for observing internal deformation of sealing ring under multi-field coupling

Abstract

The invention discloses an experimental device suitable for observing internal deformation of a sealing ring under multi-field coupling. The experimental device comprises a mechanical loading module, an external field applying module and an observation module. The device is novel and reasonable in structure, the mechanical loading module is constructed to simulate continuous application of radial compression load of the sealing ring from an original state to a sealing working state, and the oil pressure / heating / refrigerating integrated module is constructed to be used for applying oil pressure and high / low temperature load near a sealing interface of the sealing ring; a force-heat-flow field coupling loading platform is jointly formed, quantitative application of multiple external fields can be flexibly carried out on the sealing ring, and the real evolution process of the internal deformation of the sealing ring can be observed under coupling of the multiple external fields in cooperation with building of the observation module. The method is suitable for simulating and establishing an accurate leakage mechanism model for piston sealing rings in hydraulic buffering / actuating devices such as undercarriages and flaps of aircrafts. The invention also has the advantages of compact structure, wide application range to various piston sealing rings, large oil pressure and high / low temperature load variation range and the like.

Description

Technical Field

[0001] The present invention belongs to the field of testing and measurement, relates to deformation measurement technology, and particularly relates to an experimental device suitable for observing the internal deformation of a sealing ring under multi-field coupling. Background Art

[0002] A sealing ring is a common sealing structure. For example, the piston sealing ring in hydraulic buffer / actuating devices such as aircraft landing gears and flaps is a key sealing structure in the equipment. It often faces severe working conditions of radial compression load, wide temperature range (high temperature or low temperature), and high hydraulic pressure coupling during actual flight. Therefore, there is inevitably a leakage problem, which affects flight safety. Therefore, simulating and establishing an accurate leakage mechanism model of the piston sealing ring has become the primary task of guiding the design of the sealing structure and ensuring flight safety.

[0003] In some solutions known to the inventors, researchers proposed a leakage mechanism model based on the mixed lubrication theory, which mainly obtains the sealing state of the piston sealing ring during operation through the stress distribution of the sealing interface calculated by quasi-static finite element. However, under the multi-field coupling of force, heat, flow, etc., the internal deformation and stress state of the piston sealing ring are extremely complex. It is difficult to obtain the accurate stress distribution of the sealing interface by quasi-static finite element means, and thus the leakage mechanism model cannot accurately predict the leakage behavior. Based on this, the present invention innovatively proposes an experimental testing technology for the real evolution process of the internal deformation of the piston sealing ring under multi-field coupling to calculate the accurate stress distribution of the sealing interface and improve the leakage mechanism model. Summary of the Invention

[0004] The purpose of the present invention is to provide an experimental device suitable for observing the internal deformation of a sealing ring under multi-field coupling, which can observe the real evolution process of the internal deformation of the sealing ring under the coupling of multiple external fields, is conducive to further calculating the accurate stress distribution of the sealing interface based on the real interface displacement field, thereby improving the leakage mechanism model, and solving the problem that it is difficult to obtain the accurate stress distribution of the sealing interface by existing quasi-static finite element means, and thus the leakage mechanism model cannot accurately predict the leakage behavior.

[0005] To achieve the above purpose, the present invention provides the following solutions:

[0006] The present invention provides an experimental device suitable for observing the internal deformation of a sealing ring under multi-field coupling, including:

[0007] A mechanical loading module, which includes a support platform, a radial loading drive, a piston, and a sleeve movably assembled outside the piston. A sealing groove for sleeving a test sealing ring is provided on the piston. When the test sealing ring is located in the sealing groove, it can seal the gap between the sleeve and the piston. A pushing structure for moving the test sealing ring is provided on the inner wall of the sleeve. One of the sleeve and the piston is fixedly connected to the support platform, and the other is connected to the radial loading drive. The radial loading drive can make the sleeve and the piston move relative to each other, and use the pushing structure to push the test sealing ring into the sealing groove to achieve radial loading of the test sealing ring;

[0008] An external field application module is provided on the sleeve or the piston. The external field application module can apply at least one external field of a hydraulic flow field, a heating field, and a refrigeration field to the test sealing ring when the test sealing ring is radially loaded;

[0009] An observation module, which can observe the internal deformation process of the test sealing ring during radial loading.

[0010] In some embodiments, an installation partition is provided inside the piston, and the installation partition is located at one end of the sealing groove;

[0011] The external field application module includes a heating component, a refrigeration component, and a hydraulic component, where:

[0012] The heating component is provided on the piston or the sleeve;

[0013] The refrigeration component is provided on the piston or the sleeve;

[0014] The hydraulic component includes a sealing plug ring and a liquid guide pipe provided in the installation partition. The sealing plug ring is sleeved outside the piston and is located at one end of the installation partition away from the sealing groove. One end of the liquid guide pipe penetrates the side wall of the piston and communicates with the gap between the piston and the sleeve. The other end of the liquid guide pipe is located on the end face of the installation partition and is used to connect to a pressure liquid source to apply a hydraulic flow field to the sealing surface of the test sealing ring at the sealing groove.

[0015] In some embodiments, the liquid guide pipe includes a liquid guide main pipe and liquid guide branch pipes. The liquid guide main pipe is provided at the center of the installation partition. A plurality of the liquid guide branch pipes are radially provided in the installation partition. One end of any one of the liquid guide branch pipes is connected to the liquid guide main pipe, and the other end of any one of the liquid guide branch pipes penetrates the side wall of the piston. The liquid guide main pipe is used to connect to the pressure liquid source.

[0016] In some embodiments, both the piston and the mounting partition are of metal structure;

[0017] The heating assembly includes a heating resistance pipe disposed on the mounting partition. A heating resistance capable of heating up is installed inside the heating resistance pipe, and the heating resistance can transfer the temperature to the test sealing ring by means of the mounting partition and the piston;

[0018] The refrigeration assembly includes a liquid nitrogen pipe disposed on the mounting partition. The liquid nitrogen pipe is used to connect to an external low-temperature nitrogen source, and the low-temperature nitrogen source can transfer the temperature to the test sealing ring by means of the mounting partition and the piston.

[0019] In some embodiments, the experimental device applicable to observing the internal deformation of the sealing ring under multi-field coupling further includes a peripheral module, which includes:

[0020] A liquid pump and a hydraulic sensor. The liquid guide pipe is externally connected to the pressure liquid source through the liquid pump and the hydraulic sensor;

[0021] A solenoid valve. The liquid nitrogen pipe is externally connected to the low-temperature nitrogen source through the solenoid valve;

[0022] A temperature sensor is disposed on the piston or the sleeve and is located at the sealing interface between the test sealing ring and the sleeve;

[0023] A controller is communicatively connected to at least one of the liquid pump, the hydraulic sensor, the solenoid valve, the temperature sensor, and the radial loading drive.

[0024] In some embodiments, a stepped groove is provided on the outer wall of the piston. The stepped groove includes a large-head end and a small-head end opposite to the large-head end. The outer diameter of the large-head end is greater than that of the small-head end, and the large-head end and the small-head end are smoothly transitionally connected; the small-head end is used for initially sleeving the test sealing ring, the large-head end serves as the sealing groove position, and the blocking and pushing structure is located at one end of the small-head end away from the large-head end. The blocking and pushing structure can move the test sealing ring from the small-head end to the large-head end when the sleeve and the piston move relative to each other, so as to realize radial loading on the test sealing ring.

[0025] In some embodiments, the blocking and pushing structure is an annular retaining ring disposed on the inner wall of the sleeve.

[0026] In some embodiments, the radial loading drive is disposed on the support platform and is connected to the bottom end of the piston; the bottom end of the sleeve is fixedly connected to the support platform.

[0027] In some embodiments, the radial loading drive is a vertical displacement loading platform, which includes:

[0028] A screw jack is arranged on the support table and is connected to the bottom end of the piston through a force sensor;

[0029] A motor is arranged on the support table and is connected to the screw jack. The motor is used to drive the screw jack to lift and lower, so as to realize the movement of the piston relative to the sleeve.

[0030] In some embodiments, the observation module is a DR image acquisition module, which includes:

[0031] A ray source is arranged outside the sleeve and is used to emit X-rays to the sealing groove position;

[0032] A detector is arranged outside the sleeve, and is respectively located on both sides of the sleeve with the ray source. The detector is used to receive the X-rays passing through the sleeve and convert them into DR images for computer processing;

[0033] A sample rotating table is arranged below the support table. The sample rotating table is used to drive the mechanical loading module to rotate in situ.

[0034] The present invention has achieved the following technical effects compared with the prior art:

[0035] The experimental device suitable for observing the internal deformation of the sealing ring under multi-field coupling proposed by the present invention has a novel and reasonable structure. By constructing a mechanical loading module to simulate the continuous application of the radial compression load of the sealing ring from the original state to the sealing working state, and constructing an integrated oil pressure / heating / cooling module for applying the oil pressure and high / low temperature loads near the sealing interface of the sealing ring, a force-thermal-fluid field coupling loading platform is jointly formed, which can flexibly apply multiple external fields quantitatively to the sealing ring. With the cooperation of the construction of the observation module, it is possible to observe the real evolution process of the internal deformation of the sealing ring under the coupling of multiple external fields, and it is applicable to the simulation and establishment of an accurate leakage mechanism model for the piston sealing rings in hydraulic buffer / actuating devices such as aircraft landing gears and flaps.

[0036] In some technical solutions disclosed by the present invention, not only can the quantitative application of the force-thermal-fluid field coupling effect be realized, but also the observation module is built based on the digital X-ray photography (DR) image acquisition module, and the in-situ observation of the internal deformation of the piston sealing ring under the force-thermal-fluid field coupling can be realized. The present invention also has the advantages of a compact experimental platform structure, a wide applicable range for various piston sealing rings, and a large variation range of oil pressure and high / low temperature loads. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required in the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0038] Figure 1 Schematic diagram of the overall structure of the experimental device for observing the internal deformation of the sealing ring under multi-field coupling disclosed in the embodiments of the present invention;

[0039] Figure 2 Schematic diagram of the main structure of the experimental device for observing the internal deformation of the sealing ring under multi-field coupling disclosed in the embodiments of the present invention;

[0040] Figure 3 Partial structure cross-sectional view of the experimental device for observing the internal deformation of the sealing ring under multi-field coupling disclosed in the embodiments of the present invention;

[0041] Figure 4 For Figure 3 Enlarged structure schematic diagram at position A in

[0042] Figure 5 Assembly schematic diagram of the stepped groove and the blocking and pushing structure disclosed in the embodiments of the present invention;

[0043] Figure 6 Sealing principle schematic diagram of the test sealing ring at the stepped groove disclosed in the embodiments of the present invention;

[0044] Figure 7 Assembly and sealing principle schematic diagram of the test sealing ring and the plugging sealing ring disclosed in the embodiments of the present invention;

[0045] Figure 8 DR image observation principle schematic diagram of the test sealing ring disclosed in the embodiments of the present invention.

[0046] In the figure, the reference numerals are: 100, experimental device for observing the internal deformation of the sealing ring under multi-field coupling;

[0047] 1, mechanical loading module; 11, support platform; 12, radial loading drive; 1201, screw jack; 1202, motor; 1203, power supply and controller interface; 13, piston; 14, sleeve; 15, stepped groove; 1501, small head end; 1502, sealing groove position; 1503, transition slope; 16, blocking and pushing structure; 17, installation partition; 18, interval; 19, force sensor; 110, connecting device; 111, heat insulation device; 112, rectangular groove;

[0048] 2. External field application module; 21. Main liquid guide pipe; 22. Liquid guide branch pipe; 23. Heating resistance pipe; 24. Liquid nitrogen pipe; 25. Sealing rubber ring for plugging.

[0049] 3. Radiation source

[0050] 4. Detector

[0051] 5. Sample rotating table

[0052] 6. Test rubber ring Specific implementation manner

[0053] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0054] The purpose of the present invention is to provide an experimental device suitable for observing the internal deformation of a rubber ring under multi-field coupling, which can observe the real evolution process of the internal deformation of the rubber ring under the coupling of multiple external fields, is conducive to further calculating the accurate sealing interface stress distribution based on the real interface displacement field, thereby improving the leakage mechanism model, and solving the problem that it is difficult to obtain the accurate sealing interface stress distribution by existing quasi-static finite element methods, and further making the leakage mechanism model unable to accurately predict the leakage behavior.

[0055] In order to make the above objects, features and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the drawings and specific implementation manners.

[0056] Such as Figures 1 to 4As shown, this embodiment provides an experimental device 100 suitable for observing the internal deformation of a sealing ring under multi-field coupling, mainly including a mechanical loading module 1, an external field application module 2, and an observation module. Among them, the mechanical loading module 1 includes a support platform 11, a radial loading drive 12, a piston 13, and a sleeve 14 movably assembled outside the piston 13. Both the sleeve 14 and the piston 13 are standard parts, and their specifications are adapted. After assembly, there is a clearance fit between the sleeve 14 and the piston 13, leaving an appropriate gap 18 (i.e., an annular gap); a sealing groove 1502 for sleeving the test sealing ring 6 to be observed is provided on the piston 13. When the test sealing ring 6 is located in the sealing groove 1502, it can seal the gap 18 between the sleeve 14 and the piston 13. At this time, the test sealing ring 6 is in a sealed working state and is subjected to the radial extrusion force of the sleeve 14 and the piston 13; a pushing structure 16 for moving the test sealing ring 6 is provided on the inner wall of the sleeve 14. One of the sleeve 14 and the piston 13 is fixedly connected to the support platform 11 (this fixed connection is preferably a detachable fixed connection, such as being fixedly assembled with the support platform 11 through connecting parts such as screws), and the other is connected to the radial loading drive 12. During use, the support platform 11 remains stationary in the driving direction of the radial loading drive 12, and the radial loading drive 12 can drive the sleeve 14 and the piston 13 to move relative to each other. In the original state, that is, before the test observation, the test sealing ring 6 is sleeved on the piston 13 but is not located in the sealing groove 1502. At this time, the test sealing ring 6 can be regarded as not being subjected to radial loading, and there is no sealed interface between it and the inner wall of the sleeve 14. By driving the sleeve 14 and the piston 13 to move relative to each other, the pushing structure 16 can be used to push the test sealing ring 6 axially along the piston 13 to the sealing groove 1502 during the movement process, so as to realize the sliding seal between the test sealing ring 6 and the sleeve 14 and complete the radial pressure loading on the test sealing ring 6; thus, it can be seen that the mechanical loading module 1 is essentially used to apply a radial pressure external field to the test sealing ring 6. The external field application module 2 is provided on the sleeve 14 or the piston 13. The external field application module 2 can apply at least one of a hydraulic flow field, a heating field, and a cooling field to the test sealing ring 6 when the test sealing ring 6 is radially loaded, so as to realize the coupling of at least one of the hydraulic flow field, the heating field, and the cooling field with the radial pressure external field and simulate the deformation conditions of the sealing ring under multi-field coupling. The observation module is disposed outside the sleeve 14 and is used to observe the deformation process of the test sealing ring 6 under multi-field coupling.

[0057] In some embodiments, such as Figure 3 and Figure 4As shown, an installation partition 17 is provided inside the piston 13, and the installation partition 17 is located at one end of the sealing groove 1502. Based on this, the external field application module 2 includes a heating component, a refrigeration component, and a hydraulic component, where: The heating component is provided on the piston 13 or the sleeve 14 and can apply a heating field to the test sealing ring 6; The refrigeration component is provided on the piston 13 or the sleeve 14 and can apply a cooling field to the test sealing ring 6; The hydraulic component includes a sealing plug 25 and a liquid guiding pipe provided in the installation partition 17. As Figure 4 and Figure 7 shown, the sealing plug 25 is sleeved outside the piston 13 and is located at the end of the installation partition 17 away from the sealing groove 1502. Generally, it is preferred that the installation partition 17 is adjacent to the sealing groove 1502 and is arranged axially lower than the sealing groove 1502 on the piston 13. At the same time, a rectangular groove 112 is provided on the outer wall of the piston 13 below the installation partition 17. The sealing plug 25 is embedded and installed in the rectangular groove 112. The piston 13 is sealed with the inner wall of the sleeve 14 through the sealing plug 25. During the test, the sealing plug 25 and the test sealing ring 6 are respectively located at the two axial ends of the installation partition 17 to block the liquid with a certain pressure discharged through the liquid guiding pipe and ensure that the liquid accurately flows to the test sealing ring 6. One end of the liquid guiding pipe penetrates the side wall of the piston 13 and communicates with the space 18 between the piston 13 and the sleeve 14. The other end of the liquid guiding pipe is located on the end face of the installation partition 17 and is used to connect to an external pressure liquid source to apply a hydraulic flow field to the sealing surface of the test sealing ring 6 at the sealing groove 1502 (i.e., the sealing interface between the test sealing ring 6 and the sleeve 14). The aforementioned pressure liquid source includes but is not limited to an oil supply device, and the oil supply device can provide oil with a certain pressure to the liquid guiding pipe, thereby realizing the application of the oil pressure external field.

[0058] In some embodiments, in order to ensure sufficient liquid application, it is preferred that the liquid guiding pipe includes a liquid guiding main pipe 21 and liquid guiding branch pipes 22. As Figure 4 shown, the liquid guiding main pipe 21 is provided at the center of the installation partition 17. A plurality of liquid guiding branch pipes 22 are radially provided in the installation partition 17. One end of any liquid guiding branch pipe 22 converges and connects to the liquid guiding main pipe 21. The other end of any liquid guiding branch pipe 22 penetrates the side wall of the piston 13 and communicates with the space 18. The liquid guiding main pipe 21 is used to connect to the aforementioned pressure liquid source.

[0059] In some embodiments, to improve the structural compactness of the entire test bench and avoid interference of the heating component and the refrigeration component with other components, it is preferred that both the heating component and the refrigeration component are arranged inside the piston 13 and integrally arranged with the aforementioned hydraulic component. Specifically: both the piston 13 and the mounting partition 17 are made of heat-conductive metal structures. The heating component includes a heating resistance pipe 23 arranged on the mounting partition 17. A heating resistance capable of heating up is installed inside the heating resistance pipe 23. After the heating resistance is powered on, it generates heat, and the temperature can be transmitted to the test sealing ring 6 by using the mounting partition 17 and the piston 13 to achieve high-temperature heating load; similarly, the refrigeration component includes a liquid nitrogen pipe 24 arranged on the mounting partition 17. The liquid nitrogen pipe 24 is used to connect to an external low-temperature nitrogen source. The low-temperature liquid nitrogen supplied to the liquid nitrogen pipe 24 can transmit the temperature to the test sealing ring 6 by using the mounting partition 17 and the piston 13 to achieve low-temperature refrigeration load.

[0060] In some embodiments, it is preferred that the mounting partition 17 and the piston 13 are integrally formed.

[0061] In some embodiments, it is preferred that the heating resistance pipe 23 is opened on the mounting partition 17 and avoids the liquid guide branch pipe 22. The heating resistance pipe 23 penetrates through the axial two ends of the mounting partition 17, and a heating resistance can be installed inside it.

[0062] In some embodiments, the liquid nitrogen pipe 24 can be a blind pipe structure opened inside the mounting partition 17 and avoids the liquid guide branch pipe 22 and the heating resistance pipe 23. After the liquid nitrogen pipe 24 is connected to the nitrogen source, the liquid nitrogen flows inside the liquid nitrogen pipe 24 and will not leak, only serving to cool the mounting partition 17. In addition, the liquid nitrogen pipe 24 can also be arranged outside the mounting partition 17, that is, one end of the liquid nitrogen pipe 24 is hermetically connected to one end face of the mounting partition 17, the other end of the liquid nitrogen pipe 24 is connected to an external nitrogen source, and the liquid nitrogen reaches the mounting partition 17 through the liquid nitrogen pipe 24 and cools the mounting partition 17.

[0063] In some embodiments, the aforementioned experimental device 100 for observing the internal deformation of the sealing ring under multi-field coupling further includes a peripheral module, which mainly includes a liquid pump, a hydraulic sensor, a solenoid valve, a temperature sensor, and a controller. The aforementioned liquid guiding main pipe 21 can be externally connected to a pressure liquid source through a pipeline, and a liquid pump for providing power for liquid flow and a hydraulic sensor for liquid pressure detection are arranged on this pipeline. The liquid nitrogen pipeline 24 can be externally connected to a low-temperature nitrogen source through a solenoid valve. The temperature sensor is arranged on the piston 13 or the sleeve 14 and is located at the sealing interface between the test sealing ring 6 and the sleeve 14. At least one of the aforementioned liquid pump, hydraulic sensor, solenoid valve, temperature sensor, and radial loading drive 12 is communicatively connected to the controller, where: the oil pressure pump is connected to the oil guiding pipeline through the controller, and the controller and the hydraulic sensor can jointly control the oil pressure at the sealing interface; the controller can control the liquid nitrogen supply amount by controlling the solenoid valve; a temperature sensor is installed near the sealing interface and can jointly control the application of high / low temperature loads with the controller.

[0064] In some embodiments, preferably, a stepped groove 15 is provided on the outer wall of the piston 13 for assembling the aforementioned test sealing ring 6. Specifically, the stepped groove 15 is a two-stage stepped groove, which includes a large-head end and a small-head end 1501 opposite to the large-head end. As Figure 5 and Figure 6 shown, the outer diameter of the large-head end is larger than the outer diameter of the small-head end 1501, and the large-head end and the small-head end 1501 can be smoothly transitionally connected through a transition ramp 1503; the small-head end 1501 is used for initially sleeving the test sealing ring 6. At this time, the test sealing ring 6 is in its original state and is not subject to radial pressure. The large-head end serves as a sealing groove position 1502, and the blocking and pushing structure 16 is located at one end of the small-head end 1501 away from the large-head end. The blocking and pushing structure 16 can move the test sealing ring 6 from the small-head end 1501 to the large-head end when the sleeve 14 and the piston 13 move relative to each other, realizing the switching of the test sealing ring 6 from the original state to the sealing working state and completing the radial loading of the test sealing ring 6.

[0065] In some embodiments, as Figure 5 shown, the blocking and pushing structure 16 is preferably an annular retaining ring provided on the inner wall of the sleeve 14.

[0066] In some embodiments, preferably, the aforementioned radial loading drive 12 is fixedly installed on the support platform 11 through connecting members such as bolts and is connected to the bottom end of the piston 13; at the same time, the bottom end of the sleeve 14 is fixedly connected to the support platform 11 through connecting members such as bolts to provide a piston chamber for the piston 13. Based on this, preferably, the aforementioned stepped groove 15, the mounting partition 17, and the rectangular groove 112 are arranged in sequence from the top end to the bottom end of the piston 13, and the small-head end 1501 faces the top end of the piston 13, and the sealing groove position 1502 faces the bottom end of the piston 13; the blocking and pushing structure 16 is always located above the sealing groove position 1502 or flush with the sealing groove position 1502. AsFigure 6 As described above, six sets of test sealing rings in the original state are sleeved on the small head end 1501. By lifting the piston 13 upward through the aforementioned radial loading drive 12, the piston 13 can move upward relative to the sleeve 14. During the upward movement, the blocking and pushing structure 16 first contacts the top of the test sealing ring 6 in the original state. After that, the test sealing ring 6 is pushed under the blocking and pushing structure 16. However, the piston 13 continues to move upward, so that relative movement occurs between the piston 13 and the test sealing ring 6 until the test sealing ring 6 reaches the sealing groove 1502 of the piston 13.

[0067] In some embodiments, the radial loading drive 12 is preferably a vertical displacement loading table, such as a jack, a vertically arranged electric slide table, an electric telescopic cylinder, a cylinder, a hydraulic cylinder, etc. In this embodiment, the vertical displacement loading table preferably adopts a jack structure, which specifically includes a screw jack 1201 and a motor 1202. The screw jack 1201 is fixedly installed on the support table 11 and is connected to the bottom end of the piston 13 through a force sensor 19. The motor 1202 is arranged on the support table 11 and is connected to the screw jack 1201. The motor 1202 is used to drive the screw jack 1201 to lift and lower, so as to realize the movement of the piston 13 relative to the sleeve 14. The above screw jack is an existing finished product, and its specific structure and working principle will not be elaborated here. The motor 1202 is preferably a servo motor, which is configured with a power supply and a controller interface 1203, and can be connected to the controller in the peripheral module through the power supply and the controller interface 1203, so as to accurately control the position and movement rate of the test sealing ring 6 on the piston 13. The force sensor 19 can monitor the friction force at the sealing interface during the continuous application of the radial compression load on the test sealing ring 6 in real time. In practical applications, the aforementioned controller can also have data receiving and processing functions, and the force sensor 19, the hydraulic sensor and the temperature sensor can all be communicatively connected to the controller.

[0068] In some embodiments, considering that a heating component and a refrigerating component are integrally arranged in the piston 13, in order to avoid heat dissipation, it is preferred that the force sensor 19 is connected to the bottom end of the piston 13 through a connecting device 110 and a heat insulation device 111 in sequence. The aforementioned connecting device 110 and heat insulation device 111 are both preferably in a cylindrical structure, and the two can be connected and assembled through connecting parts such as bolts. The heat insulation device 111 can adopt a ceramic heat insulation ring, etc.

[0069] In some embodiments, the observation module is preferably a DR image acquisition module (the full name of DR is "digital radiography", that is, digital X-ray radiography), specifically a micro-CT device. This device specifically includes a radiation source 3, a detector 4, and a sample rotating stage 5. The radiation source 3 is arranged outside the sleeve 14 and can be supported and installed through corresponding mounting brackets and other structures. The radiation source 3 is generally arranged at the same height as the sealing groove position 1502 and is used to emit X-rays to the sealing groove position 1502. The detector 4 is arranged outside the sleeve 14 and can be supported and installed through corresponding mounting brackets and other structures. The detector 4 and the radiation source 3 are respectively located on both sides of the sleeve 14. The detector 4 is used to receive the X-rays penetrating the sleeve 14 and convert them into DR images for computer processing (that is, the real-time DR image of the test sealing ring 6). The sample rotating stage 5 is arranged below the support table 11 and is used to support and install the entire mechanical loading module 1. The sample rotating stage 5 is an existing finished product and is mainly used to drive the mechanical loading module 1 to rotate in place, facilitating the radiation source 3 to emit X-rays at multiple angles to the sleeve 14 and realizing a 360-degree omnidirectional observation of the test sealing ring 6. The aforementioned micro-CT device can specifically select the Zeiss Xradia 520 Versa X-ray microscope device.

[0070] As can be seen from the above, the observation module selects a DR image acquisition module. Its radiation source 3 emits X-rays to the sleeve 14, enabling transmission observation of the cross-section of the sealing ring and achieving the purpose of observing the internal deformation of the sealing ring, thus solving the problem of the "invisibility" of the internal deformation of the current sealing ring. The coupling of this observation module with the aforementioned multi-field coupling loading device realizes the rapid in-situ observation of the internal deformation of the sealing ring under the coupling of force-thermal-fluid fields.

[0071] In some embodiments, the experimental device 100 applicable to the observation of the internal deformation of the sealing ring under multi-field coupling can be specifically configured with heating resistors, liquid nitrogen supply sources, oil supply devices, etc. Among them, the heating resistor can adopt a finished product resistance wire or other heating resistors; the liquid nitrogen supply source can adopt a liquid nitrogen tank.

[0072] To sum up, in this solution, the mechanical loading module 1 is used to apply a radial compression load to the test sealing ring 6 from the original state to the sealing working state. The test sealing ring 6 is installed inside the stepped groove 15 on the outer wall of the piston 13, and in the original state, it is located at the smaller-diameter small head end 1501, so that the test sealing ring 6 is in the original undeformed state. When the piston 13 moves upward, the test sealing ring 6 is pushed from the small head end 150 to the larger-diameter sealing groove position 1502, thereby realizing the continuous application of the radial compression load to the test sealing ring 6. The design principle of the stepped groove 15 to achieve the continuous application of the radial compression load is as Figure 5 and Figure 6 shown.

[0073] The external field application module 2 is simultaneously provided with a heating component, a refrigerating component, and a hydraulic component. Innovatively, the functions of oil pressure loading and temperature loading are integrated onto the piston 13, achieving the integration of oil pressure / heating / refrigeration. It can be used to apply oil pressure loads and high / low temperature loads near the sealing interface of the sealing ring, thereby realizing the quantitative application of the force-thermal-fluid field coupling effect. Specifically: By arranging an installation partition 17 between the rectangular groove 112 and the stepped groove 15, and opening an oil guiding pipeline in the installation partition 17 for liquid oil transportation, the oil pressure loading at the sealing interface is realized. This design can also effectively avoid the high-pressure effect of liquid oil on the piston and the force loading device in the traditional testing device; By machining a liquid nitrogen pipeline 24 and a heating resistance pipeline 23 inside the piston 13, the application of high / low temperature loads can be realized by utilizing the relatively high heat conduction efficiency of the metal material.

[0074] The DR image acquisition module is used to continuously acquire DR images of the internal deformation evolution of the test sealing ring 6 during the application of the force-thermal-fluid field coupling external field. The continuous acquisition of DR images mainly targets the following two processes: the process of applying radial compression load to the test sealing ring 6 from the original state to the sealing working state, and the process of applying oil pressure load and high / low temperature load in the sealing working state. The entire mechanical loading module 1 equipped with the test sealing ring 6 is fixed on the sample rotating table 5. The X-rays emitted by the radiation source 3 pass through the test sealing ring 6, and the transmitted X-rays are received on the detector 4 and converted into DR images for computer processing. This micro-CT device can acquire DR images at a rate of at least 2 seconds per frame. The principle of the DR image continuous acquisition module for in-situ observation of the internal deformation of the sealing ring is as Figure 8 shown.

[0075] Taking the piston sealing ring in hydraulic buffer / actuating devices such as aircraft landing gears and flaps as the test sealing ring 6, the usage method and experimental principle of the experimental device 100 applicable to the observation of the internal deformation of the sealing ring under multi-field coupling are specifically described below. The usage process is as follows:

[0076] Step 1: Prepare the test sealing ring 6 to be tested, and check whether there are damages on the surface of the sealing structure that affect the sealing performance; Check off-site whether the components such as the mechanical loading module 1, the external field application module 2, and the observation module are complete, and verify off-site whether they can normally achieve extreme working conditions such as high oil pressure and high / low temperature, to avoid dangerous situations such as personal injury and equipment damage during the experiment.

[0077] Step 2: Install the test sealing ring 6 into the stepped groove 15 on the piston 13. At this time, a plugging sealing ring 25 is arranged in the rectangular groove 112, and then push the piston 13 into the sleeve 14. Further check whether the test sealing ring 6 in the stepped groove 15 is located at the stepped part with a smaller diameter, whether the upper end of the test sealing ring 6 is located below the stop structure 16 of the sleeve 14, and whether the plugging sealing ring 25 is in a normal interference fit state.

[0078] Step 3: Fix the support table 11 of the mechanical loading module 1 to the sample rotating table 5 of the micro-CT device through bolts. Synchronously adjust the xyz coordinates and rotation angle of the sample rotating table 5, and the z coordinates of the radiation source 3 and the detector 4 to ensure that the circumferential section of the test sealing ring 6 is included within the field of view, and the pixel resolution is lower than 5μm. The sample rotating table 5, the radiation source 3, and the detector 4 are all existing finished products, and their specific structures and working principles will not be elaborated here.

[0079] Step 4: The radial loading drive 12 lifts the piston 13, so that the piston 13 moves upward at a uniform speed of 0.5 mm / s until the stop structure 16 completely pushes the test sealing ring 6 in the stepped groove 15 to the stepped part with a larger diameter (i.e., the sealing groove position 1502), reaching the sealing working state of the test sealing ring 6, and synchronously record the value of the force sensor 19.

[0080] Step 5: At this time, the test sealing ring 6 and the plugging sealing ring 25 are in the same working state. Keep the current room temperature unchanged and gradually apply oil pressure at a rate of 0.5 MPa / s. The range of oil pressure application is 0 MPa to 38 MPa.

[0081] Step 6: When the piston 13 starts to move in Step 4, synchronously control the micro-CT device to continuously collect DR images of the internal deformation evolution of the test sealing ring 6 at a rate of 2 frames per second.

[0082] Step 7: To further study the influence of different temperatures on the internal deformation evolution of the test sealing ring 6, repeat Steps 2 to 6, and adjust the temperature load in Step 5. The range of temperature load application is -50°C to 160°C.

[0083] Step 8: After completing all the tests, reduce the oil pressure to zero and remove the mechanical loading module 1; after the temperature of the device returns to room temperature, disassemble the test sealing ring 6.

[0084] As described above, the experimental device 100 for observing the internal deformation of the sealing ring under multi-field coupling in this solution constructs a mechanical loading module to continuously apply the radial compression load of the piston sealing ring from the original state to the sealing working state, and constructs an integrated oil pressure / heating / cooling module for applying the oil pressure and high / low temperature loads near the sealing interface of the piston sealing ring. Together, they form a force-thermal-fluid field coupling loading platform, which can quantitatively apply the force-thermal-fluid field coupling effect. With the construction of a digital X-ray radiography (DR) image acquisition module based on a micro-CT device, the in-situ observation of the internal deformation of the piston sealing ring under the force-thermal-fluid field coupling is realized. This solution has the significant advantages of quantitatively applying the force-thermal-fluid field coupling effect and in-situ observing the internal deformation of the piston sealing ring, and also has the advantages of a compact experimental platform structure, a wide range of applicability to various piston sealing rings, and a large range of changes in oil pressure and high / low temperature loads.

[0085] It should be noted that the structures, proportions, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the conditions under which the present invention can be implemented. Therefore, they do not have a substantial technical meaning. Any modification of the structure, change in the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle", and "one" cited in this specification are only for the convenience of description and are not used to limit the scope of implementation of the present invention. The change or adjustment of their relative relationships, without substantial change in the technical content, should also be regarded as the scope within which the present invention can be implemented.

[0086] Specific examples are used in the present invention to elaborate on the principles and implementation manners of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, there will be changes in the specific implementation manners and application scopes according to the idea of the present invention. In summary, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. An experimental device suitable for observing the internal deformation of a sealing ring under multi-field coupling, characterized in that: include: A mechanical loading module (1) comprises a support platform (11), a radial loading drive (12), a piston (13) and a sleeve (14) movably mounted on the outside of the piston (13); the piston (13) is provided with a sealing groove (1502) for mounting a test sealing ring (6); when the test sealing ring (6) is located in the sealing groove (1502), the gap (18) between the sleeve (14) and the piston (13) can be sealed; the inner wall of the sleeve (14) is provided with a sealing groove (1502) for mounting a test sealing ring (6); The push-block structure (16) of the test sealing ring (6) is driven, one of the sleeve (14) and the piston (13) is fixedly connected to the support platform (11), and the other is connected to the radial loading drive (12), the radial loading drive (12) can make the sleeve (14) and the piston (13) move relative to each other, and use the push-block structure (16) to push the test sealing ring (6) to the sealing groove (1502), so as to realize radial loading of the test sealing ring (6); An external field applying module (2) is arranged on the sleeve (14) or the piston (13), and the external field applying module (2) is capable of applying at least one external field of a hydraulic flow field, a heating field and a cooling field to the test sealing ring (6) when the test sealing ring (6) is radially loaded; An observation module is capable of observing the internal deformation process of the test sealing ring (6) when radial loading is performed.

2. The experimental device for observing the internal deformation of the sealing ring under multi-field coupling according to claim 1 is characterized in that: A mounting baffle (17) is provided inside the piston (13), and the mounting baffle (17) is located at one end of the sealing groove (1502); The external field application module (2) comprises a heating component, a refrigeration component and a hydraulic component, wherein: The heating component is arranged on the piston (13) or the sleeve (14); The refrigeration component is arranged on the piston (13) or the sleeve (14); The hydraulic assembly includes a sealing ring (25) and a fluid conduit opened in the mounting baffle (17); the sealing ring (25) is sleeved on the outside of the piston (13) and is located at the end of the mounting baffle (17) away from the sealing groove (1502); one end of the fluid conduit passes through the side wall of the piston (13) and is connected to the gap (18) between the piston (13) and the sleeve (14); the other end of the fluid conduit is located on the end face of the mounting baffle (17) and is used to connect an external pressure liquid source to apply a hydraulic flow field to the sealing surface of the test sealing ring (6) at the sealing groove (1502).

3. The experimental device for observing the internal deformation of the sealing ring under multi-field coupling according to claim 2 is characterized in that: The liquid guiding pipeline comprises a liquid guiding main pipe (21) and liquid guiding branch pipes (22). The liquid guiding main pipe (21) is opened at the center of the mounting partition (17). A plurality of liquid guiding branch pipes (22) are opened in the mounting partition (17) along its radial direction. One end of any liquid guiding branch pipe (22) is connected to the liquid guiding main pipe (21), and the other end of any liquid guiding branch pipe (22) passes through the side wall of the piston (13). The liquid guiding main pipe (21) is used for externally connecting to the pressure liquid source.

4. The experimental device for observing the internal deformation of the sealing ring under multi-field coupling according to claim 2 is characterized in that: The piston (13) and the mounting partition (17) are both metal structures; The heating assembly comprises a heating resistor pipe (23) arranged on the mounting baffle (17), wherein a heating resistor capable of heating and raising the temperature is installed in the heating resistor pipe (23), and the heating resistor can transfer the temperature to the test sealing ring (6) by using the mounting baffle (17) and the piston (13); The refrigeration assembly comprises a liquid nitrogen pipeline (24) arranged on the mounting baffle (17), wherein the liquid nitrogen pipeline (24) is used to be externally connected to a low-temperature nitrogen source, and the low-temperature nitrogen source can transfer temperature to the test sealing ring (6) by using the mounting baffle (17) and the piston (13).

5. The experimental device for observing the internal deformation of the sealing ring under multi-field coupling according to claim 4 is characterized in that: Also included are peripheral modules, which include: A liquid pump and a hydraulic pressure sensor, wherein the liquid guide pipe is externally connected to the pressure liquid source through the liquid pump and the hydraulic pressure sensor; A solenoid valve, wherein the liquid nitrogen pipeline (24) is externally connected to the low-temperature nitrogen source through the solenoid valve; a temperature sensor, which is arranged on the piston (13) or the sleeve (14) and is located at the sealing interface between the test sealing ring (6) and the sleeve (14); A controller is communicatively connected to at least one of the liquid pump, the hydraulic pressure sensor, the solenoid valve, the temperature sensor and the radial loading drive (12).

6. The experimental device for observing the internal deformation of a sealing ring under multi-field coupling according to any one of claims 1 to 5, characterized in that: The outer wall of the piston (13) is provided with a stepped groove (15), and the stepped groove (15) includes a large head end and a small head end (1501) opposite to the large head end, the outer diameter of the large head end is larger than the outer diameter of the small head end (1501), and the large head end and the small head end (1501) are smoothly transitioned and connected; the small head end (1501) is used for initially fitting the test sealing ring (6), the large head end serves as the sealing groove (1502), and the push-blocking structure (16) is located at the end of the small head end (1501) away from the large head end. When the sleeve (14) and the piston (13) move relative to each other, the push-blocking structure (16) can move the test sealing ring (6) from the small head end (1501) to the large head end, thereby realizing radial loading of the test sealing ring (6).

7. The experimental device for observing the internal deformation of a sealing ring under multi-field coupling according to any one of claims 1 to 5, characterized in that: The thrust-blocking structure (16) is an annular retaining ring arranged on the inner wall of the sleeve (14).

8. The experimental device for observing the internal deformation of a sealing ring under multi-field coupling according to any one of claims 1 to 5, characterized in that: The radial loading drive (12) is arranged on the support platform (11) and is connected to the bottom end of the piston (13); the bottom end of the sleeve (14) is fixedly connected to the support platform (11).

9. The experimental device for observing the internal deformation of a sealing ring under multi-field coupling according to claim 8, characterized in that: The radial loading drive (12) is a vertical displacement loading platform, which comprises: A screw jack (1201) is disposed on the support platform (11) and connected to the bottom end of the piston (13) via a force sensor (19); The motor (1202) is arranged on the support platform (11) and connected to the screw jack (1201). The motor (1202) is used to drive the screw jack (1201) to rise and fall, so as to realize the movement of the piston (13) relative to the sleeve (14).

10. The experimental device for observing the internal deformation of a sealing ring under multi-field coupling according to any one of claims 1 to 5, characterized in that: The observation module is a DR image acquisition module, which includes: A ray source (3) is arranged outside the sleeve (14) and is used to emit X-rays toward the sealing groove (1502); a detector (4) disposed outside the sleeve (14) and located on both sides of the sleeve (14) together with the radiation source (3); the detector (4) is used to receive X-rays transmitted through the sleeve (14) and convert them into DR images for computer processing; A sample rotating platform (5) is arranged below the supporting platform (11), and the sample rotating platform (5) is used to drive the mechanical loading module (1) to rotate in situ.

Images