A folding rudder torque element accelerated life testing device

Abstract

This invention discloses an accelerated life testing device for a folding rudder torque element, comprising a torque element fixing unit, an oil bath container, a data acquisition and processing unit, and a circulating oil bath. The circulating oil bath is connected to the oil bath container, and the torque element is installed inside the oil bath container via the torque element fixing unit. The data acquisition and processing unit is connected to the torque element fixing unit via a data cable. This invention can automatically measure the torque data of the torque element during accelerated life testing without removing it from the testing device; and only a few parts need to be replaced to perform accelerated life testing on torque elements of different lengths or interfaces, making it highly versatile; the oil bath container has multiple heat insulation protection measures, ensuring high safety; the torque element is immersed in the oil, and the heated oil transfers temperature to the torque element, making it more evenly heated; by setting the oil heating temperature, the storage environment temperature of the torque element can be precisely controlled, effectively improving the accuracy and validity of the test data.

Description

Technical Field

[0001] This invention belongs to the field of testing technology for torsion components of folding rudders, and specifically relates to an accelerated life testing device for torsion components of folding rudders. Background Technology

[0002] A folding rudder is a control mechanism installed on an aircraft to control its flight direction. During storage, when subjected to external loads, the folding rudder's torque element undergoes elastic deformation and stores elastic potential energy. When the aircraft launches, the external load is removed, and the torque element converts the stored elastic potential energy into mechanical energy, driving the folding rudder to deploy rapidly. The torque element plays a crucial role in this process, and studying its storage lifespan is beneficial for assessing the safety and reliability of the aircraft.

[0003] If the torque element fails during long-term storage, its torque will gradually decrease, causing the folding rudder to malfunction. Under normal storage conditions, the stress relaxation of the torque element is extremely slow and difficult to detect, posing a risk of aircraft launch accidents. Although stress relaxation tests on naturally stored torque elements can reveal their stress relaxation patterns, these tests often take several years.

[0004] To determine the stress relaxation characteristics of torque components in a short period for studying storage life, accelerated life testing can be conducted. This involves increasing the ambient temperature or introducing other accelerating stresses during storage to expedite stress relaxation. The storage life under normal operating conditions can then be predicted using stress relaxation models and accelerated life models. Some accelerated life tests place the torque component in a heating chamber to increase the storage temperature and accelerate stress relaxation. However, this method requires repeatedly removing the torque component from the heating chamber during the test to measure its torque, making real-time torque data measurement difficult. Furthermore, uneven heating of the torque component in the heating chamber can lead to inaccurate test data.

[0005] Existing accelerated testing technologies mainly use air-heated chambers to accelerate temperature: Chinese patent CN112504588A discloses an accelerated stress relaxation test device for torsion springs, which uses a heating chamber and requires stopping the machine and opening the cover to measure the torque; Chinese patent CN110873643A discloses an accelerated storage test system for spiral springs, which also uses a chamber for heating and cannot achieve continuous online temperature data acquisition; Chinese patent CN107458580B discloses a manufacturing method for a folding rudder torsion bar, but does not involve an accelerated life test device.

[0006] Although the above-mentioned existing technologies use temperature as an accelerating stress to achieve accelerated life testing, they also have obvious drawbacks: 1) uneven heating of air and large temperature fluctuations; 2) the components must be removed for measurement during the test, and real-time data acquisition is not possible; 3) large data errors and low test efficiency; 4) it is difficult to apply both temperature and load as accelerating stresses at the same time. Summary of the Invention

[0007] The purpose of this invention is to provide an accelerated life testing device for folding rudder torque components, addressing the technical problems described in the background art.

[0008] The technical solution of this invention: A folding rudder torque element accelerated life test device includes a torque element fixing unit, an oil bath container, a data acquisition and processing unit, and a circulating oil bath pot. The circulating oil bath pot is connected to the oil bath container. The torque element is installed inside the oil bath container through the torque element fixing unit. The data acquisition and processing unit is connected to the torque element fixing unit through a data cable.

[0009] The torque element fixing unit includes a support part and a torque measuring part; The support unit includes a base, a torque element mounting seat, a support cylinder, an auxiliary mounting plate, and a flange. The torque element mounting seat and the support cylinder are respectively mounted on the base with screws. The auxiliary mounting plate is mounted below the flange, and the flange is mounted on the support cylinder with screws. The torque measurement unit includes a bearing mounting base, bearing A, a support base, a pin, a loading connector, bearing B, a torque sensor, and a torque element connector. The bearing mounting base has an interface adapted to the flange. Bearing A is mounted on the bearing mounting base. The support base is mounted to the bearing mounting base by screws. The pin is detachably inserted into the loading connector. One end of the loading connector is mounted to the torque sensor by screws, and the other end is mounted in the support base through bearing B. One side of the torque element connector is mounted to the torque sensor by screws, and the other side passes through bearing A and connects to the torque element.

[0010] The torque element mounting base is provided with a torque element mounting groove, and a torque element is matched and installed in the torque element mounting groove. The torque element is installed on one side of the torque sensor, and the support cylinder is provided with a through hole.

[0011] A heat insulation pad A is installed between the support base and the bearing mounting base. A bearing washer A is installed on the loading joint. A bearing washer B is installed on the torque element joint. A heat insulation pad B is installed on the outside of the torque sensor.

[0012] The oil bath container includes a top panel, a container body, side panels, and a frame. The container body is installed inside the frame, the top panel is installed on the container body and the frame with screws, and the side panels are installed on the side of the frame.

[0013] An asbestos rubber gasket is installed between the top panel and the container body, and casters are installed at the bottom of the frame.

[0014] The container body includes an outer shell, an inner shell, a cylindrical container, a support plate A, a support plate B, a pipe interface A, a pipe interface B, and a connecting flange. The support plate A is installed on the lower side of the cylindrical container, the cylindrical container is installed inside the inner shell, the support plate B is installed between the outer shell and the inner shell, the connecting flange is located on the top of the cylindrical container and on the outside of the inner shell, the pipe interface A is installed on the bottom side of the inner shell, and the pipe interface B is installed on the top side of the inner shell.

[0015] The data acquisition and processing unit includes a computer and a temperature sensor. The computer is connected to the torque sensor and the temperature sensor via data cables. The temperature sensor is mounted on the support.

[0016] Pipe interface A is connected to pipe C, pipe interface B is connected to pipe D, pipe C is connected to the outlet end of the lower part of the circulating oil bath, and pipe D is connected to the inlet end of the upper part of the circulating oil bath.

[0017] The support base is integrally provided with a hexagonal boss A, and the loading connector is integrally provided with a hexagonal boss B.

[0018] The beneficial effects of this invention are: This invention can automatically measure the torque data of torque elements during accelerated life testing without removing them from the testing device; it can perform accelerated life testing on torque elements of different lengths or interfaces by replacing only a few parts, making it highly versatile; the oil bath container of this invention has multiple heat insulation protection measures, ensuring high safety; by immersing the torque element in oil, the heated oil transfers temperature to the torque element, making it more evenly heated; by setting the oil heating temperature, the ambient temperature of the torque element can be precisely controlled, improving the accuracy and validity of the test data; this invention can simultaneously apply both load and ambient temperature as accelerated stress to the torque element. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a partial cross-sectional view of the torque element fixing unit in this invention; Figure 3 This is an exploded view of the torque element fixing unit in this invention; Figure 4 This is a schematic diagram of the structure of the torque element mounting base in this invention; Figure 5 This is an exploded view of the oil bath container in this invention; Figure 6 This is a cross-sectional view of the container body of the present invention; Figure 7 This is a schematic diagram of oil circulation in this invention.

[0020] Reference numerals: 10-Torque element fixing unit, 11-Support, 12-Torque measuring unit, 20-Oil bath container, 30-Data acquisition and processing unit, 40-Circulating oil bath, 101-Base, 102-Torque element mounting seat, 103-Torque element, 104-Support cylinder, 105-Auxiliary mounting plate, 106-Flange, 107-Bearing mounting seat, 108-Heat insulation pad A, 109-Bearing A, 110-Support seat, 111-Bearing washer A, 112-Pin, 113-Loading joint, 114-Bearing B, 115-Torque sensor, 116-Heat insulation pad B, 117-Torque element joint, 11 8-Bearing washer B, 201-Top panel, 202-Asbestos rubber washer, 203-Container body, 204-Side plate, 205-Frame, 206-Cast wheel, 301-Computer, 302-Data cable, 303-Temperature sensor, 401-Pipe C, 402-Pipe D, 1021-Torque element mounting groove, 1101-Hexagonal boss A, 1131-Hexagonal boss B, 2031-Outer shell, 2032-Inner shell, 2033-Cylindrical container, 2034-Support plate A, 2035-Support plate B, 2036-Pipe interface A, 2037-Pipe interface B, 2038-Connecting flange. Detailed Implementation

[0021] Example 1 refer to Figure 1 This embodiment discloses an accelerated life testing device for a folding rudder torque element, including a torque element fixing unit 10, an oil bath container 20, a data acquisition and processing unit 30, and a circulating oil bath 40. The torque element fixing unit 10 is used to fix the torque element at a specified angle and has the function of measuring torque. The oil bath container 20 is used to install the torque element fixing unit 10 and is connected to the circulating oil bath 40 through two pipes to transfer temperature. The stored torque and temperature data of the torque element are periodically measured by a torque sensor 115 and a temperature sensor 303. After the test, the data can be directly calculated and analyzed using a computer 301. The circulating oil bath 40 is used to heat the oil to a specified temperature and pump it out. The oil circulation method is as follows: Figure 7 As shown.

[0022] The structure of the torque element fixing unit 10 is as follows: Figures 2-4 As shown, it consists of a support part 11 and a torque measuring part 12.

[0023] The support unit 11 provides support and mounting interfaces for the torque element 103 and the torque measuring unit 12, and consists of a base 101, a torque element mounting seat 102, a support cylinder 104, an auxiliary mounting plate 105, and a flange 106. The torque element mounting seat 102 and the support cylinder 104 are respectively mounted on the base 101 with screws. The torque element mounting seat 102 is provided with a torque element mounting groove 1021 for mounting the torque element 103. The auxiliary mounting plate 105 is installed below the flange 106 for mounting the torque element fixing unit 10 onto the oil bath container 20 and also has a heat insulation function. The flange 106 is mounted on the support cylinder 104 with screws for connecting to the torque measuring unit 12.

[0024] The torque measuring unit 12 is used to limit the movement of the torque element 103 and measure the torque. It consists of a bearing mounting base 107, a heat insulation pad A 108, a bearing A 109, a support base 110, a bearing washer A 111, a pin 112, a loading joint 113, a bearing B 114, a torque sensor 115, a heat insulation pad B 116, a torque element joint 117, and a bearing washer B 118. The bearing mounting base 107 is used to mount the bearing A 109 and has an interface corresponding to the flange 106 for connecting the torque measuring unit 12 and the support unit 11; the support base 110 is used to mount the bearing B 114, and the support base 110 is mounted to the bearing mounting base 107 by screws, with a heat insulation pad A 108 installed between the two; one side of the torque element connector 117 is mounted to the torque sensor 115 by screws, and the other side passes through the bearing A 109 and connects to the torque element 103; one side of the loading connector 113 is mounted to the torque sensor 115 by screws, and the other side passes through the bearing B 114; bearing washers A 111 and B 118 are respectively mounted on the loading connector 113 and the torque element connector 117; the heat insulation pad B 116 is installed around the torque sensor 115 for heat insulation.

[0025] An exploded view of the oil bath container 20 is shown below. Figure 5 As shown, the container 20 consists of a top panel 201, an asbestos rubber gasket 202, a container body 203, side panels 204, a frame 205, and casters 206. The frame 205 supports the container body 203 and the torque element fixing unit 10, and provides an installation interface. The top panel 201 is mounted on the container body 203 and the frame 205 with screws for support and heat insulation. The asbestos rubber gasket 202 is installed between the top panel 201 and the container body 203 for sealing and heat insulation. The side panels 204 are installed around the frame 205 for heat insulation and protection. The casters 206 are installed at the bottom of the frame 205 to facilitate movement of the oil bath container 20.

[0026] The sectional view of container body 203 is as follows Figure 6As shown, it consists of an outer shell 2031, an inner shell 2032, a cylindrical container 2033, a support plate A 2034, a support plate B 2035, a pipe interface A 2036, a pipe interface B 2037, and a connecting flange 2038. The gap between the outer shell 2031 and the inner shell 2032 is used to install heat insulation material to reduce the temperature of the outer surface of the container body 203; the inner shell 2032 forms a container, and the heated oil flows in through pipe interface A 2036 and flows out through pipe interface B 2037 when the liquid level is high; the top of the cylindrical container 2033 has an opening for holding oil and installing the torque element fixing unit 10; the support plate A 2034 is installed on the lower side of the cylindrical container 2033 to support the cylindrical container 2033; the support plate B 2035 is installed between the outer shell 2031 and the inner shell 2032 to support the inner shell 2032; the connecting flange 2038 is located on the top of the cylindrical container 2033 and serves as the installation interface for connecting the top panel 201.

[0027] The data acquisition and processing unit 30 includes a computer 301, a data cable 302, and a temperature sensor 303. The computer 301 is connected to the torque sensor 115 and the temperature sensor 303 via the data cable 302. The torque sensor 115 is located on one side of the torque element 103 and is used to periodically collect torque data of the torque element 103 during storage. The temperature sensor 303 is mounted on the support 11 and is immersed in oil along with it to collect ambient temperature data of the torque element 103 during storage. The torque and temperature data collected during the experiment are stored in the computer 301, and the computer 301 can be used directly to analyze and calculate these data after the experiment.

[0028] The circulating oil bath 40 is used to circulate and heat the oil. One side of pipes C 401 and D 402 is connected to the circulating oil bath 40, and the other side is connected to pipe interface A 2036 and pipe interface B 2037, respectively. The heated oil is output to the inner shell 2032 through pipe C 401; the oil in the inner shell 2032 flows into the circulating oil bath 40 through pipe D 402.

[0029] Example 2 This embodiment provides a method for accelerated life testing of a folding rudder torque element, using the aforementioned accelerated life testing device for a folding rudder torque element, and includes the following steps: Step 1: Connect the circulating oil bath 40 to the oil bath container 20 using pipes C 401 and D 402; Step 2: Add oil to the cylindrical container 2033 at the top of the circulating oil bath 40 and the oil bath container 20 respectively; Step 3: Place the torque element 103 in the support part 11 of the torque element fixing unit 10, and insert one end into the torque element mounting groove 1021. Step 4: Insert the other end of the torque element 103 into the groove of the torque element connector 117, and use screws to connect the torque measuring part 12 of the torque element fixing unit 10 to the support part 11. Step 5: Place a wrench on the hexagonal boss A 1101 of the support 110 to restrict its rotation, and use another wrench to rotate on the hexagonal boss B 1131 of the loading connector 113. After rotating to the predetermined angle, insert the pin 112 into the through hole of the loading connector 113 to put the torque element 103 into the loaded state. Step 6: Place the torque element fixing unit 10 into the cylindrical container 2033 at the top of the oil bath container 20, and connect the torque sensor 115 to the computer 301 via the data cable 302. Step 7: Set the heating temperature of the circulating oil bath 40 and turn on the heating and circulation functions; Step 8: Start the data acquisition software in computer 301. The software acquires the torque data of torque element 103 at a fixed frequency. Step 9: After the predetermined test time is reached, turn off the heating and circulation functions of the circulating oil bath 40, remove the torque element fixing unit 10 from the cylindrical container 2033 at the top of the oil bath container 20, and remove the torque element 103. Step 10: Using the same torque element 103, repeat steps 3-9 to conduct multiple tests at different temperatures. Step 11: Analyze the data collected during the experiment; First, the lifetime characteristics corresponding to each test temperature are calculated based on the stress relaxation model of the torsion element. The formula for calculating the stress relaxation model of the torsion element is as follows: (1) Where t is the stress relaxation time of the torque element; σ is the residual stress of the torque element at time t; a is the model intercept; and b is the model slope. In the actual isothermal accelerated storage experiment, a series of time points t were recorded by the torque sensor 115. i and the corresponding residual stress value σ i Since the model is a logarithmic function, directly fitting the curve is not intuitive. To facilitate the solution, the time variable is first replaced by letting X = ln(t) and Y = σ. Then equation (1) is transformed into a linear equation: (2) After completing the variable substitution, each set of data (t) measured in the experiment i , σi All of these can be converted to (X) i , Y i ), that is (ln(t i ), σ i The values ​​of a and b can be obtained by applying the standard least squares method to fit a straight line to these transformed points: (3) (4) in, and X i and Y i The average value.

[0030] Define a failure threshold σ th The failure time t at each temperature can be solved by inverse kinematics. f , t f This is the lifetime characteristic ξ in the accelerated model. The failure time t = t f At that time, the residual stress σ = σ th Substituting these values ​​into equation (1) which has already fitted a and b, the lifetime characteristic t can be obtained. f Value: (5) In the multi-gradient accelerated storage experiment, at each acceleration temperature T i Under these conditions, a specific set of (a) will be fitted. i ,b i Using the same failure threshold σ th Substituting these values ​​into equation (5) for each temperature, the acceleration temperature T can be calculated. i Corresponding lifespan characteristics: (6) Secondly, linear fitting based on the accelerated model: In this embodiment, the acceleration model is the Arrhenius model, and the calculation formula is as follows: (7) Where ξ is the lifetime characteristic; A is a positive constant; K is the Boltzmann constant; T is the absolute temperature; and E is the activation energy. E directly reflects the material's ability to resist thermal degradation and stress decay. The larger the value, the higher the thermal energy required to induce stress relaxation, and the more stable the material's performance. Taking the logarithm of both sides of the above equation, we get: (8) Where α and β are undetermined coefficients; α = lnA; β = E / K. Let the ordinate Y... A = ln(ξ), x-coordinate XA = 1 / T for the data point set (T) i , t fi By performing a linear fit, α and β can be obtained.

[0031] Step 12, based on step 11, yields the stress relaxation expression for the torque element 103 at a specified storage temperature, thereby predicting its storage life: α, β and the predicted temperature T p Substituting into equation (8), we can find the result at temperature T. p Under the storage environment, the stress decays to σ th Required forecast time ξ p : (9) In this application, the 'e' involved in Equations 5, 6, 7 and 9 are all natural bases, approximately equal to 2.71828.

[0032] In this embodiment, during accelerated life testing, a torque element mounting base with grooves of different angles can be used to simultaneously apply both load and temperature-induced accelerated stresses.

Claims

1. A device for accelerated life testing of a folding rudder torque element, characterized in that... The system includes a torque element fixing unit (10), an oil bath container (20), a data acquisition and processing unit (30), and a circulating oil bath pot (40). The circulating oil bath pot (40) is connected to the oil bath container (20). A torque element (103) is installed inside the oil bath container (20) through the torque element fixing unit (10). The data acquisition and processing unit (30) is connected to the torque element fixing unit (10) through a data cable (302).

2. The accelerated life testing device for folding rudder torque element according to claim 1, characterized in that: The torque element fixing unit (10) includes a support part (11) and a torque measuring part (12). The support unit (11) includes a base (101), a torque element mounting seat (102), a support cylinder (104), an auxiliary mounting plate (105), and a flange (106). The torque element mounting seat (102) and the support cylinder (104) are respectively mounted on the base (101) with screws. The auxiliary mounting plate (105) is mounted below the flange (106). The flange (106) is mounted on the support cylinder (104) with screws. The torque measuring unit (12) includes a bearing mounting base (107), bearing A (109), support base (110), pin (112), loading joint (113), bearing B (114), torque sensor (115), and torque element joint (117). The bearing mounting base (107) is provided with an interface that is compatible with the flange (106). Bearing A (109) is mounted on the bearing mounting base (107). Support base (110) is mounted to bearing mounting base (107) by screws. Pin (112) is detachably inserted into loading joint (113). One end of loading joint (113) is mounted on torque sensor (115) by screws, and the other end is mounted in support base (110) through bearing B (114). Torque element joint (117) is mounted on torque sensor (115) on one side by screws, and the other side passes through bearing A (109) and is connected to torque element (103).

3. The accelerated life testing device for folding rudder torque elements according to claim 2, characterized in that: The torque element mounting base (102) is provided with a torque element mounting groove (1021), and a torque element (103) is matched and installed in the torque element mounting groove (1021). The torque element (103) is installed on one side of the torque sensor (115), and the support cylinder (104) is provided with a through hole.

4. The accelerated life testing device for folding rudder torque element according to claim 2, characterized in that: A heat insulation pad A (108) is installed between the support base (110) and the bearing mounting base (107). A bearing washer A (111) is installed on the loading joint (113). A bearing washer B (118) is installed on the torque element joint (117). A heat insulation pad B (116) is installed on the outside of the torque sensor (115).

5. The accelerated life testing device for folding rudder torque element according to claim 1, characterized in that: The oil bath container (20) includes a top panel (201), a container body (203), a side panel (204), and a frame (205). The container body (203) is installed inside the frame (205). The top panel (201) is installed on the container body (203) and the frame (205) by screws. The side panel (204) is installed on the side of the frame (205).

6. The accelerated life testing device for folding rudder torque element according to claim 5, characterized in that: An asbestos rubber gasket (202) is installed between the top panel (201) and the container body (203), and casters (206) are installed at the bottom of the frame (205).

7. The accelerated life testing device for folding rudder torque elements according to claim 5, characterized in that: The container body (203) includes an outer shell (2031), an inner shell (2032), a cylindrical container (2033), a support plate A (2034), a support plate B (2035), a pipe interface A (2036), a pipe interface B (2037), and a connecting flange (2038). The support plate A (2034) is installed on the lower side of the cylindrical container (2033), the cylindrical container (2033) is installed inside the inner shell (2032), the support plate B (2035) is installed between the outer shell (2031) and the inner shell (2032), the connecting flange (2038) is located on the top of the cylindrical container (2033) and on the outside of the inner shell (2032), the pipe interface A (2036) is installed on the bottom side of the inner shell (2032), and the pipe interface B (2037) is installed on the top side of the inner shell (2032).

8. The accelerated life testing device for folding rudder torque element according to claim 1, characterized in that: The data acquisition and processing unit (30) includes a computer (301) and a temperature sensor (303). The computer (301) is connected to the torque sensor (115) and the temperature sensor (303) respectively via a data cable (302). The temperature sensor (303) is mounted on the support (11).

9. The accelerated life testing device for folding rudder torque element according to claim 7, characterized in that: Pipe interface A (2036) is connected to pipe C (401), pipe interface B (2037) is connected to pipe D (402), pipe C (401) is connected to the lower outlet end of the circulating oil bath (40), and pipe D (402) is connected to the upper inlet end of the circulating oil bath (40).

10. The accelerated life testing device for folding rudder torque element according to claim 2, characterized in that: The support base (110) is integrally provided with a hexagonal boss A (1101), and the loading connector (113) is integrally provided with a hexagonal boss B (1131).

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