Reciprocating sealing test device and verification method for aviation hydraulic actuator

Abstract

The invention discloses a reciprocating sealing test device of an aviation hydraulic actuator and a verification method, and belongs to the field of aviation airborne equipment test and verification. Comprising an end cover, a nut, an outer cylinder, an inner hexagon screw, a pipe joint, a limiting block, a partition baffle, a piston rod, a lining and the like, and all the parts are assembled to form the complete component-level sealing test device. Performing sealing element inspection before and after an experiment on the to-be-tested sealing element, and inspecting the quality of the movable surface of the test device; then the sealing element is assembled on a test device, and installation technology adaptability inspection is carried out; the test device is installed on a test bench, and sealing characteristic tests including a running-in test, a normal-temperature, high-temperature and low-temperature performance test, a low-pressure static test and a high-pressure static test are carried out; performing environment adaptability tests including low-temperature storage, low-temperature work, high-temperature storage, high-temperature work and temperature shock; sealing life durability tests including normal-temperature, high-temperature and low-temperature motion durability tests are completed; and performing decomposition inspection after the test is finished.

Description

Technical Field

[0001] The invention belongs to the technical field of component-level verification tests, and in particular relates to a reciprocating seal test device and a verification method for an aviation hydraulic actuator. Background Art

[0002] The trend of high pressure and high power in aircraft hydraulic systems is well known. The current mature hydraulic system pressure in China is 21MPa. Although the technical standard system of 28MPa pressure system is still being improved, the domestic hydraulic system has already used 28MPa pressure. Tracking the development of foreign aircraft hydraulic systems, foreign hydraulic system suppliers have successfully used 35MPa in civil aircraft B787 and A380. Through the investigation, statistics and analysis of the current status of sealing of electromechanical products in my country, whether it is dynamic seals or static seals, there is a certain degree of leakage problem.

[0003] The combined seal performance test mainly carries out the sealing performance assessment of the combined seal under the condition of multi-factor coupling, explores the combined seal performance selection criteria, provides data support and verification for the response law and failure model of the force-heat-flow multi-field coupling factors, and provides verification and guidance for the optimization and regulation of the combined seal. For aspects such as seal failure risk, durability and reliability improvement, there is a lack of design methods and means for sealing performance optimization and comprehensive regulation, a lack of effective rapid verification means, a long verification cycle and high cost, and problems with the reliability of the solution. Usually, tests under static and conventional conditions can meet the needs, but under actual working conditions, many problems arise in the use of equipment, such as leakage, eccentric wear, piston rod damage, etc. Summary of the invention

[0004] Purpose of the present invention:

[0005] According to the requirements of aviation hydraulic actuators for verification standards of combined seals, the present invention provides a reciprocating seal test device and verification method for hydraulic actuators, realizes the ability to verify the combined seal of hydraulic actuators in a linear reciprocating test, and promotes the quality improvement of aviation hydraulic actuator seals.

[0006] Technical solution:

[0007] A reciprocating seal test device for an aviation hydraulic actuator, comprising an outer cylinder 3, a piston rod 8 and a bushing 9, wherein the outer cylinder 3 has an oil inlet and an oil outlet, the bushing 9 is coaxially arranged in the outer cylinder 3, and the bushing 9 is provided with a bushing oil through hole 20, wherein the bushing oil through hole 20 corresponds to the oil inlet and the oil outlet of the outer cylinder 3;

[0008] Two inner static sealing grooves 11 are arranged on the outer circle of the bushing 9, and the two inner static sealing grooves are symmetrically arranged on both sides of the bushing oil passage 20, and the inner static sealing grooves 11 are provided with O-rings and retaining rings; outer static sealing grooves 12 are arranged on the outer circle surfaces at both ends of the bushing 9, and the outer static sealing grooves 12 are provided with O-rings and retaining rings;

[0009] The piston rod 8 is slidably arranged in the bushing 9, and piston rod combined sealing grooves 15 are arranged on the outer circumferential surfaces of both ends of the piston rod 8. The two ends of the piston rod 8 are sleeved with the partition baffle 7 and the end cover 1 in sequence from the inside to the outside, and a piston rod support ring groove 16 is formed between the end surface of the partition baffle 7 close to the piston rod combined sealing groove 15 and the piston rod 8; the piston rod combined sealing groove 15 is provided with a combined seal, and the piston rod support ring groove 16 is provided with a support ring;

[0010] The inner surface of the partition baffle 7 is provided with a partition baffle static sealing groove 18, and the outer surface is provided with a partition baffle combined sealing groove 17, the partition baffle combined sealing groove 17 is provided with a combined sealing member, and the partition baffle static sealing groove 18 is provided with an O-ring and a retaining ring;

[0011] An end cover static sealing groove 14 is arranged on the inner circumference of the end cover 1, and an end cover scraper ring groove 13 is arranged on the outer circumference. An O-ring and a retaining ring are arranged in the end cover static sealing groove 14, and a scraper ring is arranged in the scraper ring groove 13.

[0012] Furthermore, the partition baffle 7 and the end cover 1 are locked on the outer circumferential surfaces at both ends of the piston rod 8 by nuts 2 .

[0013] Furthermore, the oil inlet of the outer cylinder 3 is installed with an oil inlet pipe joint 10 through the hexagon socket screw 4, and the oil outlet of the outer cylinder 3 is installed with an oil outlet pipe joint 5 through the hexagon socket screw 4; a pipe joint static sealing groove 19 is provided on the outer circumferential surface of the oil inlet pipe joint 10 that contacts the inner wall of the oil inlet of the outer cylinder 3, and a pipe joint static sealing groove 19 is provided on the outer circumferential surface of the oil outlet pipe joint 5 that contacts the inner wall of the oil outlet of the outer cylinder 3, and an O-ring and a retaining ring are provided in the pipe joint static sealing groove 19.

[0014] Furthermore, limit blocks 6 are provided on both sides of the outer cylinder 3 to limit the bushing 9 .

[0015] Furthermore, leakage oil ports 21 are provided at both ends of the outer tube 3 , and the leakage oil ports 21 are located between the inner end surface of the limit block 6 and the outer end surface of the bushing 9 .

[0016] 6. A verification method for a reciprocating seal test device for an aviation hydraulic actuator, including a sealing property test, an environmental adaptability test and a reciprocating life test of a combined seal.

[0017] Further, the sealing property test of the combined seal comprises the following steps:

[0018] Step 11: Confirm the test conditions, including high temperature T, according to the hydraulic actuator product specifications 高 , low temperature T 低 , and high pressure P 高 , low pressure P 低 ;

[0019] Step 12: Install the sealing test device on the test bench, start the program, and reciprocate the piston rod 8 in the bushing 9 for at least 500 times to complete the running-in test of the combined seal to be verified, and end the program;

[0020] Step 13: Start the program again, and introduce 15-35°C normal temperature oil into the sealed oil chamber between the bushing 9 and the piston rod 8 from the oil inlet pipe joint 10, close the oil outlet pipe joint 5, and perform a 3-minute pressure holding test, and record the leakage;

[0021] Step 14: Set the reciprocating stroke and frequency according to the actual working conditions, so that the combined seal to be verified is under high pressure P 高 and low pressure P 低 The lower piston rod reciprocates 200 times, and the test data is recorded to complete the normal temperature performance test;

[0022] Step 15: Place the test device in a temperature control box and adjust the temperature of the temperature control box to T at a rate of 3°C / min. 高 After the temperature in the temperature control box stabilizes, keep it for a while and wait for the combined seal and oil to reach T 高 After stabilization, carry out a 3-minute pressure test under high pressure and record the leakage;

[0023] Step 16: According to the actual working conditions, 高 and P 低 The lower piston rod 8 reciprocates 200 times, records the leakage test data, and completes the high temperature performance test;

[0024] Step 17: Place the test device in a temperature control box and adjust the temperature of the temperature control box to T at a rate of 3°C / min. 低 Temperature, after the temperature in the temperature control box stabilizes, keep it for a while, and wait for the combined seal and oil to reach T 低 After stabilization, carry out a 3-minute pressure test under high pressure and record the leakage;

[0025] Step 18: According to the actual working conditions, 高 and P 低 The lower piston rod 8 reciprocates 200 times, records the leakage test data, and completes the low temperature performance test;

[0026] Step 19: Install the test device on a low-pressure static sealing test bench, introduce 0.02MPa pressure oil from the oil inlet pipe connection 10 and maintain it for 3 minutes, record the leakage situation, and complete the low-pressure static sealing test; install the test device on a high-pressure static sealing test bench, provide oil pressures of 50%, 100% and 150% of the rated working pressure of the actuator, respectively, maintain them for 3 minutes each, and record the leakage situation.

[0027] Furthermore, the environmental adaptability test of the combined seal is: conducting 5 environmental adaptability tests: low temperature storage, low temperature operation, high temperature storage, high temperature operation, and temperature shock. The test steps are carried out in accordance with GJB150A-2009 Military Equipment Laboratory Environmental Test Method. The environmental adaptability tests are all carried out by installing the combined seal on the test device.

[0028] Among them, low-temperature storage, high-temperature storage and temperature shock tests require that the test device be naturally filled with working medium without applying additional liquid pressure; low-temperature working and high-temperature working tests require that the test device be filled with working medium at rated working pressure.

[0029] Before and after each environmental adaptability test, the combined seal is subjected to a normal temperature performance test.

[0030] Further, the reciprocating life test of the combined seal includes the following steps:

[0031] Step 21: Determine the normal temperature and high temperature T according to the proportion of each operating condition during the entire life cycle of the hydraulic product in which the combined seal is applied. 高 , low temperature T 低 The number of reciprocating motions in the reciprocating motion durability test is a multi-stage life test, and N is defined as 常 is the number of reciprocating motions at room temperature, N 高 is the number of high temperature reciprocating motions, N 低 The number of low temperature reciprocating motions;

[0032] Step 22: Install the test device on the test bench, start the program, set the stroke and frequency of the electric cylinder on the test bench according to the actual working conditions, start the electric cylinder, and the combined seal to be verified is placed in the P 高 and P 低 The following reciprocating work N 常 / 2 times, record the leakage at the end of the test and complete the normal temperature reciprocating motion durability test;

[0033] Step 23: Place the test device in a temperature control box and adjust the temperature of the temperature control box to T at a rate not exceeding 3°C / min. 高 After the temperature in the temperature control box stabilizes, wait for the combined seal and oil to reach T 高 And stable, set the electric cylinder stroke and frequency according to the actual working conditions, start the electric cylinder, and the combined seal is in high pressure P高 and P 低 The following reciprocating work N 高 / 2 times, record the leakage at the end of the test and complete the high temperature reciprocating motion durability test;

[0034] Step 24: Place the test device in a temperature control box and adjust the temperature of the temperature control box to T at a rate not exceeding 3°C / min. 低 After the temperature in the temperature control box stabilizes, wait for the combined seal and oil to reach T 低 And stable, set the electric cylinder stroke and frequency according to the actual working conditions, start the electric cylinder, and the combined seal is in high pressure P 高 and P 低 The following reciprocating work N 高 / 2 times, record the leakage situation at the end of the test and complete the low-temperature reciprocating motion durability test.

[0035] Furthermore, the combined seals that have completed the sealing characteristics test, environmental adaptability test and reciprocating life test are disassembled and inspected, photographed for evidence and recorded.

[0036] Beneficial Effects

[0037] The present invention proposes a test device for verifying the combined seal of an aviation hydraulic actuator, including an end cover, a nut, an outer cylinder, a hexagon socket screw, a pipe joint, a stopper, a partition baffle, a piston rod and a bushing, etc., and a complete component-level sealing test device is formed by assembling the various components; first, the seal to be tested is inspected before and after the experiment, including appearance inspection, size inspection, and the quality inspection of the active surface of the test device; then the seal is assembled on the test device, and the installation process adaptability inspection is carried out; the test device is installed on the test bench, and a sealing characteristic test is carried out, including a running-in test, a normal temperature, high temperature and low temperature performance test, a low pressure static test and a high pressure static test; then an environmental adaptability test is carried out, including low temperature storage, low temperature operation, high temperature storage, high temperature operation, and temperature shock; then a sealing life durability test is completed, including normal temperature, high temperature, and low temperature motion durability tests; finally, a disassembly inspection is carried out after the test is completed. The present invention solves the demand for sealing component-level test verification of high-quality hydraulic actuators in the modern aviation field, has a high degree of integration and specificity in the structure and verification method of the device, and has a good prospect for practical engineering application. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 Schematic diagram of the test device of the present invention;

[0039] Figure 2 It is a schematic diagram of the appearance of the test device of the present invention;

[0040] Figure 3 This is the test method flow of the present invention. DETAILED DESCRIPTION

[0041] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. The described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] The present invention will be further described in detail below with reference to the accompanying drawings and specific examples: Figure 1-2 As shown, the present invention proposes a reciprocating seal test device for an aviation hydraulic actuator, and the component-level verification device includes an end cover 1, a nut 2, an outer cylinder 3, a hexagon socket screw 4, an oil outlet pipe joint 5, a limit block 6, a partition baffle 7, a piston rod 8, a bushing 9, an oil inlet pipe joint 10, a bushing inner static sealing groove 11, a bushing outer static sealing groove 12, an end cover scraper ring groove 13, an end cover static sealing groove 14, a piston rod combined sealing groove 15, a piston rod support ring groove 16, a partition baffle combined sealing groove 17, a partition baffle static sealing groove 18, a pipe joint static sealing groove 19, a bushing oil port 20, an oil leakage port 21, etc.

[0043] In this embodiment, leakage oil ports 21 are left at the lower sides of the outer cylinder for collecting the leaked medium.

[0044] In this embodiment, a bushing oil passage 20 is provided in the middle of the bushing, and O-rings and retaining rings are installed at the positions of the bushing inner static sealing groove 11 and the bushing outer static sealing groove 12. The bushing with the installed sealing ring is inserted from the center of the outer tube, and a sealed oil chamber is formed between the bushing and the outer tube by the inner sealing of the bushing inner static sealing groove 11.

[0045] In this embodiment, a combined seal is installed in the piston rod combined seal groove 15 , and a support ring is installed in the piston rod support ring groove 16 .

[0046] In this embodiment, a combined seal is installed in the combined sealing groove 17 of the partition baffle, and an O-ring and a retaining ring are installed in the static sealing groove 18 of the partition baffle. The partition baffle 7 with the installed seal is inserted from both ends of the piston rod 8, and the flat end surface of the partition baffle 7 is tightly fitted with the piston head end surface of the piston rod 8, so that the support ring groove forms a complete groove.

[0047] In this embodiment, a scraper ring is installed in the scraper ring groove 13 of the end cover, and an O-ring and a retaining ring are installed in the static sealing groove 14 of the end cover. The end cover 1 with the seal installed is inserted from both ends of the piston rod 8, and the flat end surface of the end cover 1 is tightly fitted with the flat end surface of the partition baffle 7, so that the scraper ring groove forms a complete groove.

[0048] In this embodiment, the nut 2 is installed to both sides of the piston rod 8 through the threads at both ends of the piston rod 8, and the nut 2 is tightened to make the end faces of the piston rod 8, the partition baffle 7 and the end cover 1 fit tightly, thereby completing the assembly of the piston rod 8.

[0049] In this embodiment, the fully assembled piston rod 8 is passed through the center of the bushing 9, and a sealed oil chamber is formed between the area between the piston rod assembly sealing groove 15 and the bushing.

[0050] In this embodiment, the limit block 6 is installed to the outer cylinder 3 through threads on both sides of the outer cylinder 3, and the limit block 6 is tightened so that the inner end surface of the limit block 6 is tightly fitted with the end surfaces on both sides of the bushing 9.

[0051] In this embodiment, the oil inlet pipe joint 10 is the same as the oil outlet pipe joint 5, an O-ring and a retaining ring are installed at the static sealing groove 19 of the pipe joint, the pipe joint equipped with the seal is installed at the oil inlet and outlet positions of the outer tube 3, and the pipe joint and the outer tube 3 are fixed with the hexagon socket screw 4, so that the working medium passes through the pipe joint, through the oil through-port of the outer tube and the bushing, and enters and exits the sealed oil chamber.

[0052] In this embodiment, a test verification method for a combined seal assembly of an aviation hydraulic actuator is also proposed, which specifically includes the following steps:

[0053] Step 1: Check seals before and after testing

[0054] Visually inspect the appearance quality of all combined seals to be verified piece by piece. Before the test, the surface of the seals to be verified must be free of obvious burrs, obvious color difference of the material, and surface damage such as pits and cracks. There are no requirements after the test. Use a universal tool microscope and other tools to measure the dimensions of all combined seals (including rubber parts and plastic parts), support rings and scraper rings piece by piece, check the dimensions of the seals and support rings in the free state, and ensure that the dimensions of the combined seals are consistent with the drawings. Use roughness testers and other equipment to measure the surface quality of the inner surface of the bushing (five elements: profile arithmetic mean deviation Ra, profile maximum peak Rp, profile maximum height Rz, profile support length rate Tp, surface inclination Rsk) to ensure that it meets the roughness requirements noted on the drawings.

[0055] Step 2: Installation process adaptability

[0056] The combined seal is installed into the piston rod combined seal groove 15 and the partition baffle combined seal groove 17 by thermal installation. The main sealing surface of the combined seal is required to have no irreversible deformation damage and bending marks, smooth surface without damage, and no axial penetration and crease on the sealing lip. After the test, the seal is no longer removed from the test device and can be directly tested for functional performance.

[0057] Step 3: Sealing characteristics test

[0058] According to the hydraulic actuator product specifications and other materials, confirm the product test conditions, including high temperature T 高 , low temperature T 低 , and high pressure P 高 , low pressure P 低 .

[0059] After the sealing test device is installed on the test bench, the program is started. The piston rod reciprocates in the bushing for at least 500 times to complete the running-in test of the combined seal to be verified. Then the program is started again, and the oil at room temperature of 15-35℃ is introduced to carry out a 3-minute pressure holding test, and the leakage situation is recorded. The reciprocating stroke and frequency are set according to the actual working conditions so that the combined seal can be tested under high pressure P 高 and low pressure P 低 The test device was placed in a temperature control box and the temperature of the temperature control box was adjusted to T at a rate of 3°C / min. 高 After the temperature in the temperature control box stabilizes, keep it for a while and wait for the combined seal and oil to reach T 高 And stabilize, first carry out a 3-minute pressure holding test under high pressure, record the leakage situation, and then according to the actual working conditions, 高 and P 低 The test device was placed in a temperature control box and the temperature of the temperature control box was adjusted to T at a rate of 3°C / min. 低 Temperature, after the temperature in the temperature control box stabilizes, keep it for a while, and wait for the combined seal and oil to reach T 低 And stabilize, first carry out a 3-minute pressure holding test under high pressure, record the leakage situation, and then according to the actual working conditions, 高 and P 低 The test device is installed on a low-pressure static sealing test bench, and 0.02MPa oil pressure is provided from the oil inlet pipe joint for 3 minutes, and the leakage situation is recorded to complete the low-pressure static sealing test; the test device is installed on a high-pressure static sealing test bench, and oil pressures of 50%, 100% and 150% of the rated working pressure of the actuator are provided respectively, and each is maintained for 3 minutes, and the leakage situation is recorded.

[0060] Step 4: Environmental adaptability test

[0061] Five environmental adaptability tests are carried out, including low-temperature storage, low-temperature operation, high-temperature storage, high-temperature operation and temperature shock. The test steps are carried out in accordance with GJB150A-2009 Military Equipment Laboratory Environmental Test Method. All environmental adaptability tests are carried out with the device.

[0062] Among them, low-temperature storage, high-temperature storage and temperature shock tests require that the test device be naturally filled with working medium without applying additional liquid pressure; low-temperature working and high-temperature working tests require that the test device be filled with working medium at rated working pressure.

[0063] Before and after each environmental test, the combined seal is subjected to a normal temperature performance test.

[0064] Step 5: Reciprocating life test

[0065] Determine the normal temperature and high temperature T according to the proportion of each working condition during the entire life cycle of the hydraulic product. 高 , low temperature T 低 The number of reciprocating motions in the reciprocating motion durability test is N. 常 is the number of reciprocating motions at room temperature, N 高 is the number of high temperature reciprocating motions, N 低 The number of low-temperature reciprocating motions.

[0066] Install the test device on the test bench, start the program, set the stroke and frequency of the electric cylinder on the test bench according to the actual working conditions, start the electric cylinder, seal P 高 and P 低 The following reciprocating work N 常 / 2 times, record the leakage at the end of the test, and complete the room temperature reciprocating motion durability test; put the test device into the temperature control box, and adjust the temperature of the temperature control box to T at a rate not exceeding 3℃ / min. 高 After the temperature in the temperature control box stabilizes, wait for the combined seal and oil to reach T 高 And stable, set the electric cylinder stroke and frequency according to the actual working conditions, start the electric cylinder, seal high pressure P 高 and P 低 The following reciprocating work N 高 / 2 times, record the leakage at the end of the test, and complete the high-temperature reciprocating motion durability test; put the test device into the temperature control box, and adjust the temperature of the temperature control box to T at a rate not exceeding 3℃ / min. 低 After the temperature in the temperature control box stabilizes, wait for the tested seal and oil to reach T 低 And stable, set the electric cylinder stroke and frequency according to the actual working conditions, start the electric cylinder, seal high pressure P 高 and P 低 The following reciprocating work N 高 / 2 times, record the leakage situation at the end of the test and complete the low-temperature reciprocating motion durability test.

[0067] Step 6: Disassembly and inspection

[0068] The combined seals that have completed all test items shall be disassembled and inspected, and photographs shall be taken for evidence collection and written records shall be made.

[0069] The second embodiment of the present invention is to provide a component-level test verification method for an aviation hydraulic actuator, which is performed using the test device of the present invention; Figure 2 As shown, a component-level test verification method for an aviation hydraulic actuator of this embodiment includes the following steps:

[0070] Step 1: Visually inspect the appearance quality of all double-triangle combination seals to be verified piece by piece. Before the test, the surface of the seals to be verified must be free of obvious burrs, obvious color difference of the material, and surface damage such as pits and cracks. There are no requirements after the test. Use a universal tool microscope and other tools to measure the dimensions of all double-triangle combination seals, support rings and scraper rings to be verified piece by piece, check the dimensions of the seals and support rings in the free state, and ensure that the dimensions of the combination seals are consistent with the drawings. Use roughness testers and other equipment to measure the surface quality of the inner surface of the bushing (five elements: profile arithmetic mean deviation Ra, profile maximum peak Rp, profile maximum height Rz, profile support length rate Tp, surface inclination Rsk) to ensure that it meets the roughness requirements noted on the drawings.

[0071] Step 2: Use heat installation to install the combined seal into the piston rod combined seal groove 15 and the partition baffle combined seal groove 17. The main sealing surface of the combined seal is required to have no irreversible deformation damage and bending marks, the surface is smooth and undamaged, and the sealing lip has no axial penetration and creases. After the test, the seal is no longer removed from the test device and can be directly tested for functional performance.

[0072] Step 3: According to the hydraulic actuator product specifications and other materials, confirm the product test conditions, including high temperature 75℃, low temperature -55℃, high pressure 35MPa, and low pressure 0.02MPa.

[0073] After installing the sealing test device on the test bench, start the program to make the seal work back and forth 500 times to complete the seal running-in test; then start the program again, pass 35MPa normal temperature oil, carry out a 3-minute pressure holding test, and record the leakage situation; set the reciprocating stroke and frequency according to the actual working conditions, make the seal work back and forth 200 times at high pressure 35MPa and low pressure 0.02MPa, record the leakage situation, and complete the normal temperature performance test; put the test device into the temperature control box, adjust the temperature of the temperature control box to 75℃ high temperature at a rate of 3℃ / min, and continue to keep warm for 2 hours after the temperature in the temperature control box stabilizes, wait for the combined seal and oil to reach 75℃ high temperature and stabilize, first carry out a 3-minute pressure holding test under high pressure, record the leakage situation, and then according to the actual working conditions, reciprocate 200 times at high pressure 35MPa and low pressure 0.02MPa, record the leakage situation The test device is placed in a temperature control box, and the temperature of the temperature control box is adjusted to a low temperature of -55°C at a rate of 3°C / min. After the temperature in the temperature control box is stable, continue to keep warm for 2 hours, wait for the combined seal and oil to reach a low temperature of -55°C and stabilize, first carry out a 3-minute pressure holding test under high pressure, record the leakage, and then according to the actual working conditions, reciprocate 200 times under high pressure 35MPa and low pressure 0.02MPa, record the leakage, and complete the low temperature performance test; install the test device on a low-pressure static pressure sealing test bench, provide 0.02MPa oil pressure for 3 minutes, record the test conditions to complete the low-pressure static sealing test; install the test device on a 35MPa high-pressure static sealing test bench, provide 50%, 100% and 150% of the rated working pressure oil pressure, respectively, maintain for 3 minutes, and record the test conditions.

[0074] Step 4: Conduct five environmental adaptability tests: low-temperature storage, low-temperature operation, high-temperature storage, high-temperature operation, and temperature shock. The test steps refer to GJB150A-2009 Military Equipment Laboratory Environmental Test Methods. All environmental adaptability tests are carried out with the device.

[0075] Among them, low-temperature storage, high-temperature storage and temperature shock tests require that the test device be naturally filled with working medium without applying additional liquid pressure; low-temperature working and high-temperature working tests require that the test device be filled with working medium at rated working pressure.

[0076] Before and after each environmental test, the combined seal is subjected to a normal temperature performance test.

[0077] Step 5: Determine the number of reciprocating motions for the reciprocating motion durability test at normal temperature, high temperature 75°C, and low temperature -55°C according to the proportion of each operating condition during the entire life cycle of the hydraulic product used, and conduct a multi-stage life test with 50,000 reciprocating motions at normal temperature, 60,000 reciprocating motions at high temperature, and 30,000 reciprocating motions at low temperature.

[0078] Install the test device on the test bench, start the program, set the stroke and frequency of the electric cylinder according to the actual working conditions, start the electric cylinder, and reciprocate 25,000 times under the high pressure of 35MPa and the low pressure of 0.02MPa for the seal. After the test, record the leakage situation and complete the normal temperature reciprocating motion durability test; put the test device into the temperature control box, adjust the temperature of the temperature control box to 75℃ at a rate not exceeding 3℃ / min, and keep it warm for 2 hours after the temperature in the temperature control box stabilizes, wait for the combined seal and oil to reach 75℃ and stabilize, set the stroke and frequency of the electric cylinder according to the actual working conditions, start the electric cylinder, and seal 35MPa The machine reciprocates 30,000 times under high pressure and 0.02MPa low pressure respectively. At the end of the test, record the leakage situation and complete the high-temperature reciprocating motion durability test. Place the test device in a temperature control box, adjust the temperature of the temperature control box to -55°C at a rate not exceeding 3°C / min, and after the temperature in the temperature control box stabilizes, continue to keep warm for 2 hours, wait for the combined seal and oil to reach -55°C and stabilize, set the stroke and frequency of the electric cylinder according to the actual working conditions, start the electric cylinder, and the seal reciprocates 15,000 times under 35MPa high pressure and 0.02MPa low pressure respectively. At the end of the test, record the leakage situation and complete the low-temperature reciprocating motion durability test.

[0079] Step 6: Disassemble and inspect the test products that have completed all test items, take photos for evidence, and make written records.

Claims

1. A reciprocating seal test device for an aviation hydraulic actuator, characterized in that: It includes an outer cylinder, a piston rod and a bushing, wherein the outer cylinder has an oil inlet and an oil outlet, the bushing is coaxially arranged in the outer cylinder, and a bushing oil through hole is arranged on the bushing, and the bushing oil through hole corresponds to the oil inlet and the oil outlet of the outer cylinder; Two inner static sealing grooves are arranged on the outer circle of the bushing, and the two inner static sealing grooves are symmetrically arranged on both sides of the bushing oil passage, and O-shaped sealing rings and retaining rings are arranged in the inner static sealing grooves of the bushing; outer static sealing grooves of the bushing are arranged on the outer circle surfaces of both ends of the bushing, and O-shaped sealing rings and retaining rings are arranged in the outer static sealing grooves of the bushing; The piston rod is slidably arranged in the bushing, and piston rod combined sealing grooves are arranged on the outer circumferential surfaces at both ends of the piston rod. The two ends of the piston rod are sleeved with a partition baffle and an end cover in sequence from the inside to the outside, and a piston rod support ring groove is formed between the end surface of the partition baffle close to the piston rod combined sealing groove and the piston rod; a combined sealing member is arranged in the piston rod combined sealing groove, and a support ring is arranged in the piston rod support ring groove; The inner circular surface of the partition baffle is provided with a partition baffle static sealing groove, the outer circular surface is provided with a partition baffle combined sealing groove, the partition baffle combined sealing groove is provided with a combined sealing member, and the partition baffle static sealing groove is provided with an O-ring and a retaining ring; An end cover static sealing groove is arranged on the inner circular surface of the end cover, an end cover scraper ring groove is arranged on the outer circular surface, an O-ring and a retaining ring are arranged in the end cover static sealing groove, and a scraper ring is arranged in the scraper ring groove.

2. The reciprocating seal test device for an aviation hydraulic actuator according to claim 1, characterized in that: The partition baffle and the end cover are locked on the outer circumferential surfaces at both ends of the piston rod through nuts.

3. The reciprocating seal test device for an aviation hydraulic actuator according to claim 1, characterized in that: The oil inlet of the outer cylinder is installed with an oil inlet pipe joint through a hexagon socket screw, and the oil outlet of the outer cylinder is installed with an oil outlet pipe joint through a hexagon socket screw; a pipe joint static sealing groove is arranged on the outer circumferential surface of the oil inlet pipe joint that contacts the inner wall of the oil inlet of the outer cylinder, and a pipe joint static sealing groove is arranged on the outer circumferential surface of the oil outlet pipe joint that contacts the inner wall of the oil outlet of the outer cylinder, and an O-ring and a retaining ring are arranged in the pipe joint static sealing groove.

4. The reciprocating seal test device for an aviation hydraulic actuator according to claim 1, characterized in that: Limit blocks are arranged on both sides of the outer cylinder to limit the bushing.

5. The reciprocating seal test device for an aviation hydraulic actuator according to claim 4, characterized in that: The two ends of the outer cylinder are provided with leakage oil ports, and the leakage oil ports are located between the inner end surface of the limit block and the outer end surface of the bushing.

6. A verification method for a reciprocating seal test device for an aviation hydraulic actuator according to any one of claims 1 to 5, characterized in that: It includes sealing property test, environmental adaptability test and reciprocating life test of combined seals.

7. The verification method according to claim 6, characterized in that: The sealing property test of the combined seal includes the following steps: Step 11: Confirm the test conditions, including high temperature T, according to the hydraulic actuator product specifications 高 , low temperature T 低 , and high pressure P 高 , low pressure P 低 ; Step 12: Install the sealing test device on the test bench, start the program, and reciprocate the piston rod in the bushing for at least 500 times to complete the running-in test of the combined seal to be verified, and end the program; Step 13: Start the program again, and introduce 15-35℃ normal temperature oil into the sealing oil chamber between the bushing and the piston rod from the oil inlet pipe joint, close the oil outlet pipe joint, and perform a 3-minute pressure test, recording the leakage situation; Step 14: Set the reciprocating stroke and frequency according to the actual working conditions, so that the combined seal to be verified is under high pressure P 高 and low pressure P 低 The lower piston rod reciprocates 200 times, and the test data is recorded to complete the normal temperature performance test; Step 15: Place the test device in a temperature control box and adjust the temperature of the temperature control box to T at a rate of 3°C / min. 高 After the temperature in the temperature control box stabilizes, keep it for a while and wait for the combined seal and oil to reach T 高 After stabilization, carry out a 3-minute pressure test under high pressure and record the leakage; Step 16: According to the actual working conditions, 高 and P 低 The lower piston rod reciprocates 200 times, records the leakage test data, and completes the high temperature performance test; Step 17: Place the test device in a temperature control box and adjust the temperature of the temperature control box to T at a rate of 3°C / min. 低 Temperature, after the temperature in the temperature control box stabilizes, keep it for a while, and wait for the combined seal and oil to reach T 低 After stabilization, carry out a 3-minute pressure test under high pressure and record the leakage; Step 18: According to the actual working conditions, 高 and P 低 The lower piston rod reciprocates 200 times, records the leakage test data, and completes the low-temperature performance test; Step 19: Install the test device on a low-pressure static sealing test bench, connect 0.02MPa pressure oil from the oil inlet pipe and maintain it for 3 minutes, record the leakage situation, and complete the low-pressure static sealing test; install the test device on a high-pressure static sealing test bench, provide oil pressures of 50%, 100% and 150% of the rated working pressure of the actuator, respectively, maintain them for 3 minutes each, and record the leakage situation.

8. The verification method according to claim 7, characterized in that: The environmental adaptability test of the combined seal is: five environmental adaptability tests are carried out: low temperature storage, low temperature operation, high temperature storage, high temperature operation, and temperature shock. The test steps are carried out in accordance with GJB150A-2009 military equipment laboratory environmental test method. The environmental adaptability test is carried out by installing the combined seal on the test device. Among them, low-temperature storage, high-temperature storage and temperature shock tests require that the test device be naturally filled with working medium without applying additional liquid pressure; low-temperature working and high-temperature working tests require that the test device be filled with working medium at rated working pressure; Before and after each environmental adaptability test, the combined seal is subjected to a normal temperature performance test.

9. The verification method according to claim 8, characterized in that: The reciprocating life test of the combined seal includes the following steps: Step 21: Determine the normal temperature and high temperature T according to the proportion of each operating condition during the entire life cycle of the hydraulic product in which the combined seal is applied. 高 , low temperature T 低 The number of reciprocating motions in the reciprocating motion durability test is a multi-stage life test, and N is defined as 常 is the number of reciprocating motions at room temperature, N 高 is the number of high temperature reciprocating motions, N 低 The number of reciprocating motions at low temperature; Step 22: Install the test device on the test bench, start the program, set the stroke and frequency of the electric cylinder on the test bench according to the actual working conditions, start the electric cylinder, and the combined seal to be verified is placed in the P 高 and P 低 The following reciprocating work N 常 / 2 times, record the leakage at the end of the test, and complete the normal temperature reciprocating motion durability test; Step 23: Place the test device in a temperature control box and adjust the temperature of the temperature control box to T at a rate not exceeding 3°C / min. 高 After the temperature in the temperature control box stabilizes, wait for the combined seal and oil to reach T 高 And stable, set the electric cylinder stroke and frequency according to the actual working conditions, start the electric cylinder, and the combined seal is in high pressure P 高 and P 低 The following reciprocating work N 高 / 2 times, record the leakage at the end of the test and complete the high temperature reciprocating motion durability test; Step 24: Place the test device in a temperature control box and adjust the temperature of the temperature control box to T at a rate not exceeding 3°C / min. 低 After the temperature in the temperature control box stabilizes, wait for the combined seal and oil to reach T 低 And stable, set the electric cylinder stroke and frequency according to the actual working conditions, start the electric cylinder, and the combined seal is in high pressure P 高 and P 低 The following reciprocating work N 高 / 2 times, record the leakage situation at the end of the test and complete the low-temperature reciprocating motion durability test.

10. The verification method according to claim 8, characterized in that: The combined seals that have completed the sealing characteristics test, environmental adaptability test and reciprocating life test are disassembled and inspected, photographed for evidence and recorded.

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