Self-circulation loading device for casing pressure fatigue test and test system

Abstract

The invention discloses a self-circulation loading device and test system for a casing pressure fatigue test, and the device comprises a basic test platform which is used as a structural support and is used for installing a test piece to carry out the pressure fatigue test; the tester oil source is used for providing hydraulic oil as a power source; the oil supply oil source is used for providing test oil; the hydraulic loading executing mechanism is respectively connected with the tester oil source, the oil supply oil source and a test cavity of the test piece, and is used for loading under the action of the pressure input by the tester oil source so as to input test oil into the test cavity and further apply a pressure load to the test piece, or is used for carrying out a return stroke resetting action under the action of the pressure input by the tester oil source; and the circulating oil supplementing device is used for enabling the output end of the hydraulic loading execution mechanism to be communicated with the test cavity when the hydraulic loading execution mechanism carries out loading action, and is also used for enabling the output end of the hydraulic loading execution mechanism to be disconnected from the test cavity and connected with an oil supply source when the hydraulic loading execution mechanism carries out return action.

Description

Technical Field

[0001] The present invention relates to the technical field of aero-engine testing, and in particular to a self-circulating loading device for casing pressure fatigue testing. In addition, the present invention also relates to a testing system comprising the self-circulating loading device for casing pressure fatigue testing. Background Art

[0002] The casing is the load-bearing part of the engine, an important part for supporting the rotor and fixing the stator, and an important load-bearing component of the engine. It bears mechanical loads such as engine thrust, inertia, torque, and internal gas pressure loads. According to the provisions of standard documents, it must be subjected to pressure tests, including static pressure tests and cyclic pressure fatigue tests.

[0003] In the pressure test, the static pressure test often uses a hand-operated hydraulic pump to pressurize the casing cavity with oil. For static pressure tests and fatigue pressure tests with large leakage, the existing test method uses an independent hydraulic oil source system to pressurize the casing. Figure 1 . The hydraulic oil source system has high power and large flow, and can be used to carry out static pressure tests and fatigue pressure tests with large leakage. However, the equipment has a complex structure, occupies a large area, has high energy consumption, and one set of equipment can only apply one pressure load. The cleanliness of the hydraulic oil running in the system is required to be above level 6. The hydraulic oil leaking from the casing during the test cannot be reused, and new oil needs to be continuously injected into the oil source system, which is extremely costly. In addition, pressure fatigue tests often use linear actuators for pressure loading. As the hydraulic oil inside the casing leaks, the hydraulic oil inside the actuator needs to be continuously injected into the casing. When the actuator stroke reaches the limit, the test equipment stops due to the limit alarm. It is necessary to manually disconnect the oil pipe connecting the actuator and the casing, re-inject hydraulic oil into the actuator cavity, and then connect the oil pipe between the actuator and the test piece to restart the test. This test method is inefficient. Summary of the invention

[0004] The present invention provides a self-circulating loading device and a testing system for a casing pressure fatigue test, so as to solve the technical problems in the prior art that when the casing fatigue cycle test actuator stroke reaches the limit, oil needs to be refilled and a set of equipment can only apply one load path, resulting in high testing cost and low efficiency.

[0005] According to one aspect of the present invention, there is provided a self-circulating loading device for a casing pressure fatigue test, comprising: The basic test platform is used as a structural support for mounting the test specimens for pressure fatigue testing; The tester oil source system is used to provide hydraulic oil as a power source; Oil supply source, used to provide test oil; A hydraulic loading actuator is respectively connected to the tester oil source system, the oil supply source and the test cavity of the test piece, and is used for performing a loading action under the pressure input from the tester oil source system to input the test oil into the test cavity of the test piece and thereby apply a pressure load to the test piece, or for performing a return stroke reset action under the pressure input from the tester oil source system; The circulating oil replenishing device is used to connect the output end of the hydraulic loading actuator with the test cavity of the test piece when the hydraulic loading actuator is in loading action, and is also used to disconnect the output end of the hydraulic loading actuator from the test cavity of the test piece and connect it to an oil supply source when the hydraulic loading actuator is in return action.

[0006] As a further improvement of the above technical solution, the circulating oil replenishing device includes a shell, a reversing seal assembly and a driving mechanism, the shell having an inner cavity, and is respectively provided with a first interface for connecting to a hydraulic loading actuator, a second interface for connecting to an oil supply source and a third interface for connecting to a test piece; the first interface, the second interface and the third interface are respectively connected to the inner cavity; the reversing seal assembly is arranged in the inner cavity, and the driving mechanism is used to drive the reversing seal assembly to move in the inner cavity to block the passage between the first interface and the second interface while connecting the first interface and the third interface, or to drive the reversing seal assembly to move in the inner cavity to block the passage between the first interface and the third interface while connecting the first interface and the second interface.

[0007] As a further improvement of the above technical solution, the reversing seal assembly includes a rod body axially inserted into the inner cavity and extending from one end of the inner cavity, sealing matching structures are symmetrically distributed at both ends of the inner cavity, and an outer wall of the rod body is provided with an elastic sealing plug for matching with the sealing matching structure at a preset interval, and the first interface is arranged on the shell at a position corresponding to the middle of the inner cavity, and the driving mechanism is used to drive the rod body to move from the second interface to the third interface direction to drive the elastic sealing plug near one end of the third interface to match with the corresponding sealing matching structure and drive the elastic sealing plug near one end of the second interface to disengage from the matching with the corresponding sealing matching structure, thereby blocking the passage between the first interface and the third interface while connecting the first interface and the second interface, and also used to drive the rod body to move from the third interface to the second interface direction to drive the elastic sealing plug near one end of the second interface to match with the corresponding sealing matching structure and drive the elastic sealing plug near one end of the third interface to disengage from the matching with the corresponding sealing matching structure, thereby blocking the passage between the first interface and the second interface while connecting the first interface and the third interface.

[0008] As a further improvement of the above technical solution, the circulating oil replenishing device also includes a first detection unit arranged between the reversing seal assembly and the driving mechanism, which is used to detect and feedback the pressure applied to the inner cavity by the driving mechanism through the reversing seal assembly.

[0009] As a further improvement of the above technical solution, the self-circulating loading device also includes a second detection unit for detecting and feeding back the liquid level height in the test chamber.

[0010] As a further improvement of the above technical solution, the hydraulic loading actuator includes an active linear actuator and a driven linear actuator, and the fourth interface and the fifth interface are respectively provided at both ends of the active linear actuator, and the fourth interface and the fifth interface are respectively connected to the oil source system of the tester, and the free end of the piston rod of the active linear actuator is transmission-connected to the free end of the piston rod of the driven linear actuator; the sixth interface and the seventh interface are respectively provided at both ends of the driven linear actuator, and the seventh interface is located at one end of the driven linear actuator away from the active linear actuator, and the The sixth interface is used to connect to the oil supply source, and the seventh interface is used as the output end of the hydraulic loading actuator to be connected to the test cavity of the test piece and the oil supply source respectively through the circulating oil replenishing device; the piston rod of the active linear actuator is used to receive the loading action of the input pressure of the tester oil source system to drive the piston rod of the driven linear actuator to press the test oil of the driven linear actuator into the test cavity, and is also used to receive the return action of the input pressure of the tester oil source system to drive the piston rod of the driven linear actuator to draw the test oil from the oil supply source for replenishing.

[0011] As a further improvement of the above technical solution, the self-circulating loading device also includes a collecting device, which is arranged on the basic test platform and is used to collect and filter the test oil leaked from the surface of the test piece during the test. The oil supply source is integrated with the collecting device.

[0012] As a further improvement of the above technical solution, the collecting device includes an oil collecting ring arranged on the working surface of the basic test platform and sleeved on the outside of the test piece, a filter assembly with a top opening arranged below the working surface of the basic test platform, and an oil storage container connected to the bottom of the filter assembly.

[0013] As a further improvement of the above technical solution, the filter assembly includes a filter cartridge and a connector, and the two ends of the connector are used to connect to the filter cartridge and the basic test platform respectively; a plurality of filter screens are layered in the filter cartridge, and the filtration level of the filter screens in the filter cartridge increases from top to bottom.

[0014] According to another aspect of the present invention, a test system is also provided, which includes the above-mentioned self-circulating loading device for casing pressure fatigue test.

[0015] The present invention has the following beneficial effects: The self-circulating loading device is provided with a tester oil source system and an oil supply source respectively. The tester oil source system provides pressure to drive the hydraulic loading actuator to perform loading action or return reset action. The oil supply source provides test oil. The hydraulic loading actuator performs loading action under the pressure input from the tester oil source system to input test oil into the test cavity of the test piece and then apply a pressure load to the test piece or performs return reset action under the pressure input from the tester oil source system. By providing a circulating oil replenishing device, the output end of the hydraulic loading actuator is connected to the test cavity of the test piece when the hydraulic loading actuator is in loading action, and the test oil inside the hydraulic loading actuator is loaded into the test cavity of the test piece. When the hydraulic loading actuator returns, the circulating oil replenishing device connects the output end of the hydraulic loading actuator to the test cavity of the test piece. The output end is disconnected from the test cavity of the test piece and connected to the oil supply source, and then the oil supply source is sucked during the return process to realize the oil replenishment of the output cavity of the hydraulic loading actuator. The circulating oil replenishing device is switched synchronously according to the action direction of the hydraulic loading actuator to realize the application of the casing pressure load and the oil replenishment from the hydraulic loading actuator to the test piece. The replenishment oil is provided by the oil supply source and does not participate in the circulation of the tester oil supply system, that is, there is no need to replenish the oil of the tester oil source system that provides the power part, thereby reducing the test cost and improving the test efficiency. On the other hand, the device can be connected to the tester oil source system and the oil supply system respectively by setting a plurality of groups of hydraulic loading actuators and circulating oil replenishing devices, thereby carrying out a plurality of groups of casing pressure tests with the power support of only one tester oil source system, thereby significantly reducing the test cost.

[0016] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings: Figure 1 This is the working principle diagram of the existing casing pressure fatigue test; Figure 2 It is a structural schematic diagram of a self-circulating loading device according to a preferred embodiment of the present invention; Figure 3 It is a structural schematic diagram of an oil collecting ring of a preferred embodiment of the present invention; Figure 4It is a schematic structural diagram of a filter cartridge of a preferred embodiment of the present invention; Figure 5 is a cross-sectional view of a filter cartridge according to a preferred embodiment of the present invention; Figure 6 is a schematic structural diagram of an oil storage container according to a preferred embodiment of the present invention; Figure 7 It is a structural schematic diagram of a hydraulic loading actuator according to a preferred embodiment of the present invention; Figure 8 is a structural schematic diagram of a circulating oil replenishing device according to a preferred embodiment of the present invention; Fig. 9 It is a cross-sectional view of a circulating oil replenishing device according to a preferred embodiment of the present invention.

[0018] Legend: 1. Basic test platform; 2. Hydraulic loading actuator; 21. Active linear actuator; 22. Driven linear actuator; 221. Sixth interface; 222. Seventh interface; 3. Circulating oil replenishing device; 31. Housing; 311. First interface; 312. Second interface; 313. Third interface; 32. Driving mechanism; 33. Rod; 34. Elastic sealing plug; 4. Collecting device; 41. Oil collecting ring; 42. Filter cartridge; 421. Step structure; 422. Filter; 43. Connector; 44. Oil storage container; 5. Test piece; 6. First detection unit; 7. Second detection unit; 8. Third detection unit; 9. Hydraulic oil pipe. DETAILED DESCRIPTION

[0019] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0020] Figure 2 It is a structural schematic diagram of a self-circulating loading device according to a preferred embodiment of the present invention; Figure 3 It is a structural schematic diagram of an oil collecting ring of a preferred embodiment of the present invention; Figure 4 It is a schematic structural diagram of a filter cartridge of a preferred embodiment of the present invention; Figure 5 is a cross-sectional view of a filter cartridge according to a preferred embodiment of the present invention; Figure 6 is a schematic structural diagram of an oil storage container according to a preferred embodiment of the present invention; Figure 7 It is a structural schematic diagram of a hydraulic loading actuator according to a preferred embodiment of the present invention; Figure 8 is a structural schematic diagram of a circulating oil replenishing device according to a preferred embodiment of the present invention; Fig. 9 It is a cross-sectional view of a circulating oil replenishing device according to a preferred embodiment of the present invention.

[0021] like Figures 2 to 9 As shown, the self-circulating loading device for casing pressure fatigue test of this embodiment includes: The basic test platform 1 is used as a structural support for installing the test piece 5 for the pressure fatigue test; the test platform can be constructed by using steel beams, test fixtures, etc., and the test piece 5 can be connected and fixed on the test platform to carry out the test work; The tester oil source system is used to provide hydraulic oil as a power source; Oil supply source, used to provide test oil; The hydraulic loading actuator 2 is respectively connected to the tester oil source system, the oil supply source and the test cavity of the test piece 5, and is used for performing a loading action under the pressure input from the tester oil source system to input the test oil into the test cavity of the test piece 5 and thus apply a pressure load to the test piece 5, or for performing a return reset action under the pressure input from the tester oil source system; The circulating oil replenishing device 3 is used to connect the output end of the hydraulic loading actuator 2 with the test cavity of the test piece 5 when the hydraulic loading actuator 2 is in loading action, and is also used to disconnect the output end of the hydraulic loading actuator 2 from the test cavity of the test piece 5 and connect it to the oil supply source when the hydraulic loading actuator 2 is in return action.

[0022] It can be understood that the self-circulating loading device is respectively provided with a tester oil source system and an oil supply source, the tester oil source system provides pressure to drive the hydraulic loading actuator 2 to perform loading action or return reset action, the oil supply source provides test oil, the hydraulic loading actuator 2 is loaded under the pressure input by the tester oil source system to input test oil into the test cavity of the test piece 5 and then apply a pressure load to the test piece 5 or perform a return reset action under the pressure input by the tester oil source system, and by providing a circulating oil replenishing device 3, when the hydraulic loading actuator 2 is in loading action, the output end of the hydraulic loading actuator 2 is connected to the test cavity of the test piece 5, and the test oil inside the hydraulic loading actuator 2 is loaded into the test cavity of the test piece 5, and when the hydraulic loading actuator 2 is in return action, the circulating oil replenishing device 3 enables the hydraulic loading actuator 2 to be connected to the test cavity of the test piece 5. The output end of the actuator 2 is disconnected from the test chamber of the test piece 5 and connected to the oil supply source, and then the oil supply source is sucked during the return process to achieve oil replenishment of the output chamber of the hydraulic loading actuator 2. According to the movement direction of the hydraulic loading actuator 2, the circulating oil replenishing device 3 synchronously matches the action to switch to achieve the application of the casing pressure load and the oil replenishment from the hydraulic loading actuator 2 to the test piece 5. The replenishment oil is provided by the oil supply source and does not participate in the circulation of the tester oil supply system, that is, there is no need to replenish the tester oil source system that provides the power part, thereby reducing the test cost and improving the test efficiency. On the other hand, the device can be connected to the tester oil source system and the oil supply system respectively by setting multiple groups of hydraulic loading actuators 2 and circulating oil replenishing devices 3, thereby carrying out multiple groups of casing pressure tests with the power support of only one tester oil source system, thereby significantly reducing the test cost.

[0023] In one embodiment, the self-circulating loading device further includes a collecting device 4, which is arranged on the basic test platform 1 and is used to collect and filter the oil leaked from the surface of the test piece 5 during the test. The oil supply source and the collecting device 4 are integrated; that is, the oil supply source contains the test oil and collects the oil leaked from the casing test piece 5 during the test. Based on the action process of the circulating oil replenishing device 3, the oil supply source and the oil leaked during the test are collected and circulated only between the output chamber of the hydraulic loading actuator 2, the test piece 5 and the collecting device 4. That is, the device not only allows the test oil and the power oil to circulate independently, but also does not need to continuously replenish new oil to the oil source system, thereby reducing the test cost and greatly improving the test efficiency. In one embodiment, the collecting device 4 includes an oil collecting ring 41 arranged on the working surface of the basic test platform 1 and sleeved on the outside of the test piece 5, a filter assembly arranged below the working surface of the basic test platform 1 and having a top opening, and an oil storage container 44 connected to the bottom of the filter assembly. The oil storage container 44 is preferably an oil storage tank, and can also be an oil storage container 44 of other structural forms; the oil collecting ring 41 limits the flow range of the oil leaking out of the surface of the casing test piece 5, so that the oil is concentrated in the area of ​​the oil collecting ring 41 and flows downward through the holes on the basic test platform 1 to fall into the filter assembly. The oil is filtered by the filter assembly under the action of gravity and flows into the oil storage container 44, thereby collecting the oil leaking from the casing during the test, so that the self-circulating loading device can realize the application of pressure load to the test piece 5, oil collection, filtration and automatic oil replenishment, and realize the cyclic reciprocating loading of the casing pressure fatigue test without the need to continuously replenish new oil, thereby reducing the test cost and improving the test efficiency.

[0024] In one embodiment, the filter assembly includes a filter cartridge 42 and a connector 43, the two ends of the connector 43 are used to connect to the filter cartridge 42 and the basic test platform 1 respectively. Preferably, the connector 43 adopts a hook structure, and hooks are respectively provided on the basic test platform 1 and the filter cartridge 42, and the filter cartridge 42 is hung below the basic test platform 1, which is convenient for disassembly and assembly, and is convenient for cleaning, maintenance and other operations; in other embodiments, the connector 43 can also be connected by means of snap-fit, threaded connection, etc., and there is no restriction on it; a plurality of filter screens 422 are layered in the filter cartridge 42, and the filtration level of the filter screens 422 in the filter cartridge 42 increases from top to bottom, that is, the fineness of the filter screens 422 increases layer by layer, to ensure that the cleanliness of the oil collected in the oil storage tank meets the use requirements; Furthermore, a step structure 421 is provided in the filter cartridge 42, and the circumferential dimension of the step structure 421 gradually decreases from top to bottom, that is, the size of the installed filter screen 422 gradually decreases from top to bottom to match the step structure 421, which is convenient for installation and removal for cleaning while also matching the permeability of the oil.

[0025] Preferably, there is space below the constructed basic test platform 1 to prevent the oil storage container 44 from entering, the structure is compact and reasonable, and the oil flows into the oil storage container 44 more efficiently, which is more convenient for oil collection.

[0026] In one embodiment, the circulating oil replenishing device 3 includes a housing 31, a reversing seal assembly and a driving mechanism 32. The housing 31 has an inner cavity. The housing 31 is provided with a first interface 311 for connecting to the hydraulic loading actuator 2, a second interface 312 for connecting to the oil supply source and a third interface 313 for connecting to the test piece 5; the first interface 311, the second interface 312 and the third interface 313 are respectively connected to the inner cavity; the reversing seal assembly is arranged in the inner cavity, and the driving mechanism 32 is used to drive the reversing seal assembly to move in the inner cavity to block the first interface 311 The passage between the first interface 311 and the second interface 312 simultaneously connects the first interface 311 and the third interface 313, or is used to drive the reversing seal component to move in the inner cavity to block the passage between the first interface 311 and the third interface 313 and simultaneously connect the first interface 311 and the second interface 312; when the hydraulic loading actuator 2 is loading, the driving mechanism 32 of the circulating oil replenishing device 3 controls the action of the reversing seal component to realize oil circuit switching, so as to block the passage between the first interface 311 and the second interface 312 and simultaneously connect the first interface 311 and the third interface 313. The oil in the output chamber of the hydraulic loading actuator 2 is loaded into the test piece 5, and a pressure load is applied to the test piece 5. During the test, the oil continues to leak. The leaked oil is filtered by the collecting device 4 and stored in the oil storage tank for reuse. After the test oil in the output chamber of the hydraulic loading actuator 2 is used up, it is necessary to refill the oil, control the hydraulic loading actuator 2 to perform a return reset action, and control the reversing seal assembly to switch the oil circuit through the driving mechanism 32 of the circulating oil replenishing device 3, and drive the reversing seal assembly to act in the inner cavity to block the first interface 311 and the third interface 312. The passage between the ports 313 simultaneously connects the first port 311 and the second port 312, and the hydraulic loading actuator 2 draws the oil in the oil storage tank into the output chamber to replenish the oil. After the oil replenishment is completed, the above action is repeated to replace the connecting channel again, and the test is continued to be carried out to realize the self-circulating loading of the casing pressure fatigue test. The leaked oil in the test is collected and circulated only between the output chamber of the hydraulic loading actuator 2, the test piece 5 and the oil storage tank, and does not participate in the circulation of the oil source system of the tester. Both oil source systems do not need to be continuously replenished with new oil, thereby reducing the test cost and improving the test efficiency.

[0027] In one embodiment, the reversing seal assembly includes a rod body 33 that is axially inserted into the inner cavity and extends from one end of the inner cavity. Sealing matching structures are symmetrically distributed at both ends of the inner cavity. The outer wall of the rod body 33 is provided with elastic sealing plugs 34 for matching with the sealing matching structure at a preset interval. The first interface 311 is provided at a position corresponding to the middle of the inner cavity on the shell 31. The preset interval is preferably smaller than the interval between the two sealing matching structures. The driving mechanism 32 is used to drive the rod body 33 to move from the second interface 312 to the third interface 313 to drive the elastic sealing plug 34 near one end of the third interface 313 to match with the corresponding sealing matching structure and drive the elastic sealing plug 34 near one end of the second interface 312 to disengage from the corresponding sealing matching structure to block the passage between the first interface 311 and the third interface 313. At the same time, the first interface 311 and the second interface 312 are connected, and the rod body 33 is also used to drive the rod body 33 to move from the third interface 313 to the second interface 312 to drive the elastic sealing plug 34 near one end of the second interface 312 to cooperate with the corresponding sealing matching structure and drive the elastic sealing plug 34 near one end of the third interface 313 to disengage from the corresponding sealing matching structure to block the passage between the first interface 311 and the second interface 312 and connect the first interface 311 and the third interface 313. By driving the rod body 33 to move toward one end, the elastic sealing plug 34 is driven to cooperate closely with the sealing structure to achieve the blocking of the corresponding oil circuit at that location and at the same time make the oil circuit at the other end conductive to achieve rapid oil circuit switching. The driving mechanism 32 can obtain power from the oil source system of the tester. The overall action is simple to execute, the implementation cost is low, and the operation is stable. In other embodiments, the preset spacing may be slightly greater than or equal to the spacing between the two sealing matching structures, and the driving mechanism 32 is used to drive the rod body 33 to move from the second interface 312 to the third interface 313 so as to drive the elastic sealing plug 34 near one end of the third interface 313 to cooperate with the corresponding sealing matching structure and generate compression, thereby simultaneously driving the elastic sealing plug 34 near one end of the second interface 312 to disengage from the cooperation with the corresponding sealing matching structure, and is also used to drive the rod body 33 to move from the third interface 313 to the second interface 312 so as to drive the elastic sealing plug 34 near one end of the second interface 312 to cooperate with the corresponding sealing matching structure and generate compression, thereby simultaneously driving the elastic sealing plug 34 near one end of the third interface 313 to disengage from the cooperation with the corresponding sealing matching structure, which also has the effect of realizing rapid switching of the oil circuit, and when the rod body 33 is not powered by the driving mechanism 32, the elastic sealing plugs 34 at both ends maintain the sealing cooperation with the corresponding sealing structure so that the oil circuits at both ends are in a blocked state, which facilitates the plugging and unplugging operations at the oil circuit interface in the state of fault shutdown, etc. It should be noted that the outer periphery of the elastic sealing plug 34 and the inner wall of the sealing structure are both constructed in a conical structure, so that when the elastic sealing plug 34 moves in the corresponding blocking direction, it gradually fits tightly with the sealing structure to achieve sealing, and when it is disengaged, a channel with sufficient space is opened for oil to pass through, with strong sealing and oil permeability; the structures at both ends are symmetrically distributed, the structure is simple, the action is simple to execute, and the reliability is strong.

[0028] In some embodiments, the rod body 33 and the elastic sealing plug 34 may be integrated, that is, the reversing sealing assembly is an integrally formed elastic structure, preferably made of elastic materials such as rubber that are low in cost, good in sealing and have a long service life.

[0029] In one embodiment, the circulating oil replenishing device 3 further includes a first detection unit 6 disposed between the reversing seal assembly and the driving mechanism 32, which is used to detect and feedback the pressure applied to the inner cavity by the driving mechanism 32 through the reversing seal assembly. Specifically, based on the setting of the first detection unit 6, the load applied to the sealing structure by the driving mechanism 32 through the elastic sealing plug 34 during the test can be verified, thereby verifying the sealing performance of the elastic sealing plug 34, and the output pressure of the driving mechanism 32 can be controlled based on the setting of the first detection unit 6, thereby adjusting the compression amount of the elastic sealing plug 34, thereby ensuring that the elastic sealing plug 34 and the sealing structure are always in a good sealing state during the test; preferably, the first detection unit 6 is implemented by a force sensor in the prior art; It should be noted that before the test, the load applied by the driving mechanism 32 is detected by the first detection unit 6 to verify the sealing performance of the rubber plug. During the test, the numerical value of the applied load can be adjusted to ensure that the test seal is always in good condition.

[0030] It should be understood that the sealing connection surfaces on the device, test piece 5 and the test tooling are sealed by setting rubber O-rings, which is a relatively mature sealing method in the prior art. It is easy and quick to install and has a service life of more than 6 months, meeting the fatigue test duration requirements.

[0031] In one embodiment, the self-circulating loading device also includes a second detection unit 7 for detecting and feeding back the liquid level height in the test chamber. Preferably, the second detection unit 7 uses a liquid level sensor of the prior art to continuously monitor the internal liquid level of the test chamber of the casing to ensure that the medium storage inside the casing meets the test requirements during the test and improve the safety of the test.

[0032] In one embodiment, the hydraulic loading actuator 2 includes an active linear actuator 21 and a driven linear actuator 22, and a fourth interface and a fifth interface are respectively provided at both ends of the active linear actuator 21, and the fourth interface and the fifth interface are respectively connected to the oil source system of the tester, and the free end of the piston rod of the active linear actuator 21 is transmission-connected to the free end of the piston rod of the driven linear actuator 22; a sixth interface 221 and a seventh interface 222 are respectively provided at both ends of the driven linear actuator 22, and the seventh interface 222 is located at one end of the driven linear actuator 22 away from the active linear actuator 21, and the sixth interface 221 is used to connect to the oil supply source, and the seventh interface 222 is used as the output end of the hydraulic loading actuator 2 to connect to the test cavity of the test piece 5 and the oil supply source through the circulating oil replenishing device 3; based on the action process and principle of the aforementioned circulating oil replenishing device 3, The piston rod of the active linear actuator 21 is loaded by the input pressure of the tester oil source system, driving the piston rod of the driven linear actuator 22 to move and then press the oil of the driven linear actuator 22 into the test chamber. The active linear actuator 21 is returned by the input pressure of the tester oil source system. At the same time, the oil circuit of the circulating oil replenishing device 3 is switched. The active linear actuator 21 drives the piston rod of the driven linear actuator 22 to draw oil from the oil supply source, that is, the oil storage container 44 for oil replenishment. It should be noted that the test chamber of the casing is provided with a third detection unit 8 to detect the pressure in the test chamber, and the action of the active linear actuator 21 is controlled based on the pressure signal fed back by the pressure sensor. The active linear actuator 21 is independently connected to the tester oil source system, and the power is provided by the tester oil source system. The driven linear actuator 22 is respectively connected to the test piece 5 and the oil storage container 44.

[0033] Preferably, the modules are connected by hydraulic oil pipes 9, and the hydraulic oil pipes 9 and the joints are connected by quick-change joints in the prior art, which are easy to plug and unplug and convenient to operate.

[0034] Preferably, the driving mechanism 32 is a third linear actuator, and is connected to the tester oil source system, powered by the tester oil source system, and controls the movement direction according to the movement direction of the active linear actuator 21 to achieve oil circuit switching control.

[0035] On the other hand, a preferred embodiment of the present invention further provides a test system, which is equipped with the above-mentioned self-circulating loading device for casing pressure fatigue testing. It should be understood that the control system, data transmission and processing system, circuit connection and related components of this test system are implemented with reference to the casing pressure fatigue cycle test system of the prior art, and will not be elaborated on in detail.

[0036] In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper", "lower", "front", "rear", etc. are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0037] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A self-circulating loading device for casing pressure fatigue test, characterized in that: include: A basic test platform (1) is used as a structural support for mounting a test piece (5) for performing a pressure fatigue test; The tester oil source system is used to provide hydraulic oil as a power source; Oil supply source, used to provide test oil; A hydraulic loading actuator (2) is respectively connected to the tester oil source system, the oil supply source and the test cavity of the test piece (5), and is used for performing a loading action under the pressure input from the tester oil source system to input test oil into the test cavity of the test piece (5) and thereby apply a pressure load to the test piece (5), or for performing a return stroke reset action under the pressure input from the tester oil source system; The circulating oil replenishing device (3) is used to connect the output end of the hydraulic loading actuator (2) with the test cavity of the test piece (5) when the hydraulic loading actuator (2) is in loading action, and is also used to disconnect the output end of the hydraulic loading actuator (2) from the test cavity of the test piece (5) and connect it to an oil supply source when the hydraulic loading actuator (2) is in return action.

2. The self-circulating loading device for casing pressure fatigue test according to claim 1 is characterized in that: The circulating oil replenishing device (3) comprises a housing (31), a reversing seal assembly and a driving mechanism (32); the housing (31) has an inner cavity; the housing (31) is provided with a first interface (311) for connecting to a hydraulic loading actuator (2), a second interface (312) for connecting to an oil supply source and a third interface (313) for connecting to a test piece (5); the first interface (311), the second interface (312) and the third interface (313) are respectively connected to the inner cavity; the reversing seal assembly ... second interface (312) for connecting to an oil supply source and a third interface (313) for connecting to a test piece (5); the first interface (311), the second interface (312) and the third interface (313) are respectively connected to the inner cavity; the reversing seal assembly is provided with a second interface (311) for connecting to an oil supply source and a third interface (313) for connecting to a test piece (5); the first interface (311), the second interface (312) and the third interface (313) are respectively connected to the inner cavity; the reversing seal assembly is provided with a second interface (311) for connecting to an oil supply source and a third interface (313) for connecting to a test piece (5); the first interface (311), the second interface (312) and the third interface (313) are respectively connected to the inner cavity; the reversing seal assembly is provided with a second interface (311) for connecting to an oil supply source and a third interface (313) for connecting to a test piece (5); the first interface (311), the second interface (312) and The component is arranged in the inner cavity, and the driving mechanism (32) is used to drive the reversing sealing component to move in the inner cavity to block the passage between the first interface (311) and the second interface (312) while enabling communication between the first interface (311) and the third interface (313), or to drive the reversing sealing component to move in the inner cavity to block the passage between the first interface (311) and the third interface (313) while enabling communication between the first interface (311) and the second interface (312).

3. The self-circulating loading device for casing pressure fatigue test according to claim 2 is characterized in that: The reversing seal assembly comprises a rod body (33) axially inserted into the inner cavity and extending from one end of the inner cavity, sealing matching structures are symmetrically arranged at both ends of the inner cavity, and an elastic sealing plug (34) for matching with the sealing matching structure is arranged at a preset interval on the outer wall of the rod body (33), the first interface (311) is arranged at a position corresponding to the middle of the inner cavity on the shell (31), and the driving mechanism (32) is used to drive the rod body (33) to move from the second interface (312) to the third interface (313) so as to drive the elastic sealing plug (34) near one end of the third interface (313) to match with the corresponding sealing matching structure and drive the elastic sealing plug (34) near one end of the second interface (312) to separate from the corresponding sealing matching structure. The sealing matching structure cooperates with the sealing matching structure to thereby block the passage between the first interface (311) and the third interface (313) and simultaneously connect the first interface (311) and the second interface (312), and is also used to drive the rod body (33) to move from the third interface (313) to the second interface (312) to drive the elastic sealing plug (34) near one end of the second interface (312) to cooperate with the corresponding sealing matching structure and drive the elastic sealing plug (34) near one end of the third interface (313) to disengage from the corresponding sealing matching structure to thereby block the passage between the first interface (311) and the second interface (312) and simultaneously connect the first interface (311) and the third interface (313).

4. The self-circulating loading device for casing pressure fatigue test according to claim 2 is characterized in that: The circulating oil replenishing device (3) further comprises a first detection unit (6) arranged between the reversing seal assembly and the driving mechanism (32), for detecting and feeding back the pressure applied to the inner cavity by the driving mechanism (32) via the reversing seal assembly.

5. The self-circulating loading device for casing pressure fatigue test according to claim 1, characterized in that: The self-circulating loading device also includes a second detection unit (7) for detecting and feeding back the liquid level height in the test chamber.

6. The self-circulating loading device for casing pressure fatigue test according to any one of claims 1 to 5, characterized in that: The hydraulic loading actuator (2) comprises an active linear actuator (21) and a driven linear actuator (22); a fourth interface and a fifth interface are respectively provided at two ends of the active linear actuator (21); the fourth interface and the fifth interface are respectively connected to the oil source system of the tester; the free end of the piston rod of the active linear actuator (21) is transmission-connected to the free end of the piston rod of the driven linear actuator (22); a sixth interface (221) and a seventh interface (222) are respectively provided at two ends of the driven linear actuator (22); the seventh interface (222) is located at one end of the driven linear actuator (22) away from the active linear actuator (21); The sixth interface (221) is used to connect to the oil supply source, and the seventh interface (222) is used as the output end of the hydraulic loading actuator (2) to be connected to the test cavity of the test piece (5) and the oil supply source through the circulating oil replenishing device (3); the piston rod of the active linear actuator (21) is used to receive the input pressure of the tester oil source system to drive the piston rod of the driven linear actuator (22) to press the test oil of the driven linear actuator (22) into the test cavity, and is also used to receive the input pressure of the tester oil source system to drive the piston rod of the driven linear actuator (22) to draw the test oil of the oil supply source into the return stroke for replenishing the oil.

7. The self-circulating loading device for casing pressure fatigue test according to any one of claims 1 to 5, characterized in that: The self-circulating loading device also includes a collecting device (4) disposed on the basic test platform (1) and used for collecting and filtering the test oil leaked from the surface of the test piece (5) during the test process. The oil supply source is integrated with the collecting device (4).

8. The self-circulating loading device for casing pressure fatigue test according to claim 7, characterized in that: The collecting device (4) comprises an oil collecting ring (41) arranged on the working surface of the basic test platform (1) and sleeved on the outside of the test piece (5), a filter assembly arranged below the working surface of the basic test platform (1) and having a top opening, and an oil storage container (44) connected to the bottom of the filter assembly.

9. The self-circulating loading device for casing pressure fatigue test according to claim 8, characterized in that: The filter assembly comprises a filter cartridge (42) and a connecting piece (43), wherein two ends of the connecting piece (43) are respectively used to connect to the filter cartridge (42) and the basic test platform (1); a plurality of filter screens (422) are arranged in layers in the filter cartridge (42), and the filter grades of the filter screens (422) in the filter cartridge (42) increase from top to bottom.

10. A test system, characterized in that: A self-circulating loading device for casing pressure fatigue testing as described in any one of claims 1 to 9 is used.

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