Accelerated life evaluation method for vehicle-mounted optical connector

Abstract

The invention discloses an accelerated life evaluation method for a vehicle-mounted optical connector, which belongs to the related technical field of vehicle-mounted connectors, and comprises the following steps: determining a limit temperature range that a material of the vehicle-mounted optical connector can bear and a limit use temperature range that the material can work normally; constructing a temperature accelerated aging evaluation model and a vibration accelerated aging evaluation model of the vehicle-mounted optical connector; and the acceleration experiment condition of the vehicle-mounted optical connector is obtained. According to the accelerated life evaluation method, accelerated evaluation of the cyclic service life of the vehicle-mounted optical connector can be realized, the evaluation accuracy of the cyclic service life of the vehicle-mounted optical connector is ensured, the test time of the cyclic service life of the vehicle-mounted optical connector is shortened, and the test efficiency of the vehicle-mounted optical connector is improved. The method provides conditions for the judgment of the cycle service life of the vehicle-mounted optical connector in different shaping stages and the rapid sampling inspection of the vehicle-mounted optical connector after mass production, provides support for the application of the vehicle-mounted optical connector, promotes the application of the vehicle-mounted optical connector in a vehicle-mounted environment, and has an excellent application prospect.

Description

Technical Field

[0001] This invention belongs to the technical field of automotive connectors, specifically relating to an accelerated life assessment method for automotive optical connectors. Background Technology

[0002] In recent years, driven by the electrification and intelligentization of automobiles, the amount of data in vehicles has exploded, and conventional radio frequency electrical connectors are increasingly unable to meet the needs of practical applications. In this context, optical signal transmission has seen rapid development in the automotive field, with major fiber optic cable manufacturers and automakers investing heavily in the development of high-speed fiber optic communication technology for vehicles.

[0003] Although both fiber optic connectors and automotive electrical connectors have been commercially available for many years, their application environments and failure mechanisms differ significantly. Applying fiber optic connectors to automotive environments has become a new research focus, and assessing their lifespan and reliability in such environments is crucial for their application in automotive applications. However, current lifespan assessments for automotive connectors primarily focus on automotive electrical connectors. As an emerging product in the automotive field, the lifespan assessment methods for automotive optical connectors are still somewhat lacking, which to some extent restricts their application. Summary of the Invention

[0004] In response to one or more of the above-mentioned defects or improvement needs of the prior art, the present invention provides an accelerated life assessment method for automotive optical connectors, which can realize accelerated life assessment of automotive optical connectors under temperature acceleration conditions and vibration acceleration conditions, and at the same time realize the life assessment of automotive optical connectors, significantly shorten the life assessment time of automotive optical connectors and improve the life assessment efficiency of automotive optical connectors.

[0005] To achieve the above objectives, the present invention provides an accelerated life assessment method for automotive optical connectors, comprising the following steps: (1) Determine the extreme temperature range that the material of the vehicle-mounted optical connector can withstand; (2) Determine the extreme operating temperature range within which the vehicle-mounted optical connector can function normally; (3) Construct a temperature-accelerated aging evaluation model for automotive optical connectors and characterize it as follows: (Formula 1) (Formula 2) (Formula 3) (Formula 4) In the formula, This represents the number of loops before the failure. Plastic strain for each cycle; This represents the number of cycles before product failure under normal operating conditions. To accelerate the number of product cycles before failure during aging cycles; To accelerate the difference between the highest and lowest temperatures during aging cycles; This represents the average temperature difference during a day's working hours under normal operating conditions. The acceleration constant is independent of temperature. The expected lifetime during equivalent accelerated experiments; The expected lifespan of the product under normal operating conditions; It is a constant; (4) Construct a vibration-accelerated aging assessment model for vehicle-mounted optical connectors and characterize it as follows: (Formula 5) In the formula, This represents the root mean square value of vibration acceleration under actual service conditions. This represents the root mean square value of vibration acceleration under equivalent acceleration experimental conditions. This represents the acceleration power spectral density under actual service vibration conditions. This represents the acceleration power spectral density corresponding to the equivalent accelerated vibration experiment. The fatigue index; (5) Determine the accelerated testing conditions for the vehicle-mounted optical connector; the accelerated testing conditions shall at least include the temperature cycling range during the testing of the optical connector samples. Limit temperature holding time, rate of temperature change, and root mean square value of vibration acceleration. And the theoretical number of cycles for accelerating the experiment. ; (6) Accelerated lifetime assessment of the vehicle-mounted optical connector under test is performed according to the accelerated test conditions.

[0006] As a further improvement of the present invention, in step (2), the process for determining the limiting operating temperature range in which the optical connector can function normally is as follows: (2.1) Connect the vehicle-mounted optical connector sample to the test optical path; (2.2) Place the vehicle-mounted optical connector sample at the highest temperature that the material can withstand. and lowest temperature The temperature reaches thermal equilibrium and remains at that point for a certain period of time. (2.3) Monitor the transmission performance of the optical connector at the above two temperatures; if the optical performance of the optical connector does not meet the requirements at a certain extreme temperature, adjust its operating temperature to a certain value within the range. And based on this, the product's transmission performance was tested again until the highest temperature at which the optical connector could operate normally was finally obtained. and lowest temperature .

[0007] As a further improvement to the present invention, temperature adjustment The values ​​are 5℃, 10℃, 15℃, or 20℃; and / or Adjusting the temperature During the subsequent sample testing process, another optical connector sample that had not participated in the experiment was used in the subsequent experiments.

[0008] As a further improvement of the present invention, in step (3), the acceleration constant The acquisition process is as follows: (3.1) Select multiple standard samples of vehicle-mounted optical connectors and assemble them into experimental wire harnesses for later use; (3.2) Set the system's permissible threshold for judging the failure of standard samples; (3.3) Set the temperature cycling range for the standard samples Among them, the temperature cycling range Includes multiple different temperature cycling ranges; (3.4) Experiments were conducted on the standard samples under each temperature cycling condition to test the life cycle of each standard sample; (3.5) Combined with (Formula 4), calculate the parameters under accelerated experiment. and And fit the parameters to obtain and The linear relationship between them ultimately yields the constant. The value of .

[0009] As a further improvement of the present invention, in process (3.3), the temperature cycling range include , , ,in, This refers to the extreme temperature range within which the product can be used normally. The selected temperature difference value.

[0010] As a further improvement of the present invention, in step (4), the root mean square value of vibration acceleration under equivalent acceleration conditions is... The acquisition process is as follows: (4.1) Setting the equivalent acceleration experiment temperature conditions Based on the determination of the constant C, and combined with (Formula 2), the acceleration factor is obtained. and The correspondence between them; (4.2) Combined with (Formula 5), ​​calculate the equivalent accelerated experimental temperature conditions. The root mean square value of vibration acceleration under the following conditions ; (4.3) Determine the measured root mean square value of vibration acceleration Does it meet the experimental requirements? If not, change it. The value is taken and the process (4.1) to (4.3) is repeated.

[0011] As a further improvement of the present invention, when determining the vibration conditions in step (5), the temperature cycle range is changed according to processes (4.1) to (4.2). The value of is used to determine the vibration conditions corresponding to different temperature cycling ranges, thus obtaining the vibration conditions and temperature cycling ranges. A table showing the correspondence between them.

[0012] As a further improvement of the present invention, based on the determination of the accelerated test conditions in step (5), accelerated life assessment tests are conducted on the same type of vehicle-mounted optical connectors to determine whether their cycle life meets the theoretical life cycle; the basis for the determination is: Under the same equivalent accelerated testing conditions, does the number of test cycles for the optical connector exceed the theoretical number of cycles? Or the theoretical number of cycles Whether the difference in the number of times between them is within the set threshold.

[0013] As a further improvement of the present invention, when conducting accelerated life assessment tests on automotive optical connectors, the criterion for determining that the automotive optical connector has not failed is as follows: During the experiment, the additional attenuation of the vehicle-mounted optical connector sample was no greater than 0.6 dB, and there was no transient interruption of more than 1 microsecond; and after the experiment, the additional attenuation of the vehicle-mounted optical connector sample was no greater than 0.3 dB.

[0014] As a further improvement to the present invention, a control experimental group was also designed: Multiple optical cable samples identical to those used in the accelerated aging test for connecting the vehicle-mounted optical connector were selected. After protecting the ends of the optical cables, they were placed under the same test conditions as the accelerated aging test. When the accelerated aging test of the vehicle-mounted optical connector determined that it had failed, the optical cables were subjected to a continuity test.

[0015] The aforementioned improved technical features can be combined with each other as long as they do not conflict with each other.

[0016] In summary, the beneficial effects of the above-described technical solutions conceived by this invention compared with the prior art include: The accelerated life assessment method for automotive optical connectors of the present invention includes the following steps: determining the extreme temperature range that the material of the automotive optical connector can withstand and the extreme operating temperature range that allows it to function normally; constructing a temperature-accelerated aging assessment model and a vibration-accelerated aging assessment model for the automotive optical connector; and obtaining the accelerated experimental conditions for the automotive optical connector. Based on the aforementioned method, the method can accurately meet the assessment and judgment of the service life of automotive optical connectors under automotive environment (vibration and temperature change environment), and fully adapt to the performance judgment requirements of automotive optical connectors.

[0017] The accelerated life assessment method for automotive optical connectors in this invention is simple in steps and easy to use. It can accelerate the assessment of the cycle life of automotive optical connectors, ensuring the accuracy of the cycle life assessment while shortening the cycle life testing time. It provides conditions for determining the cycle life of automotive optical connectors at different stages of finalization and for rapid sampling inspection after mass production. It supports the promotion and application of automotive optical connectors, promotes their application in automotive environments, and has excellent application prospects. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a flowchart illustrating the accelerated life assessment method for vehicle-mounted optical connectors in an embodiment of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0021] In the description of this invention, it should be understood that, unless otherwise expressly specified and limited, the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0022] Furthermore, unless otherwise expressly defined, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise expressly and specifically defined.

[0023] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0024] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0025] Below, for reference Figure 1 A method for accelerating the lifespan assessment of an automotive optical connector according to a preferred embodiment of the present invention is described.

[0026] The method in the preferred embodiment aims to construct an accelerated life assessment system for a specific type of automotive optical connector. Based on the establishment of temperature-accelerated aging and vibration-accelerated aging models within the system, and in conjunction with experiments on standard optical connector samples, accelerated life assessment experimental conditions for this type of automotive optical connector are obtained. This provides a basis for determining the cycle life of automotive optical connectors at different stages of product development, and is particularly suitable for determining the cycle life of finalized products at different stages and for sampling inspection of mass-produced products. Thus, it provides a basis for performance evaluation of automotive optical connector applications.

[0027] Specifically, in the preferred embodiment, the accelerated life assessment method for automotive optical connectors preferably includes the following steps: (1) Determine the extreme temperature range that the automotive optical connector material can withstand based on the material composition of the automotive optical connector to be tested. ;

[0028] In the formula, This refers to the maximum temperature range that the connector material can withstand. ~ ; This refers to the highest temperature that the connector material can withstand. This refers to the lowest temperature that the connector material can withstand.

[0029] (2) Determine the extreme operating temperature range within which the vehicle-mounted optical connector can function normally. ; Optical connectors are integral units composed of various material components, and the temperature resistance of these materials represents the limits of the connector's operating temperature range. However, in reality, due to differences in the coefficients of thermal expansion of materials, the deformation varies at different temperatures, leading to internal stress that affects the actual signal transmission of the optical fiber. Therefore, the maximum temperature range within which an optical connector can operate normally is usually narrower than the maximum temperature range that the connector material itself can withstand, and needs to be determined separately.

[0030] In a preferred embodiment, the process for determining the limiting operating temperature range within which the optical connector can function normally is as follows: (2.1) Connect the vehicle-mounted optical connector sample to the test optical path; (2.2) Place the vehicle-mounted optical connector sample at the highest temperature that the material can withstand. and lowest temperature The temperature reaches thermal equilibrium and remains at that point for a certain period of time. In a preferred embodiment, the test holding time is further preferably 2 hours.

[0031] (2.3) Monitor the transmission performance of the optical connector at the above two temperatures; if the optical performance of the optical connector does not meet the requirements at a certain extreme temperature, adjust its operating temperature to a certain value within the range. And based on this, the product's transmission performance was tested again until the highest temperature at which the optical connector could operate normally was finally obtained. and lowest temperature .

[0032] For example, in actual value selection, the temperature is adjusted. The preferred values ​​are 5℃, 10℃, 15℃ or 20℃.

[0033] The highest temperature that the optical connector can withstand under normal operating conditions Taking the acquisition process as an example: If the optical connector is at its highest temperature If the optical performance does not meet the requirements, the experimental temperature will be adjusted to ( ). - The experiment in step (2.2) continues at this temperature. If the product still fails to function properly, the temperature is adjusted further and lowered. Repeat the above experimental process until the optical performance of the optical connector meets the requirements, and obtain the highest temperature at which the optical connector can operate normally. ,in, It is a natural number.

[0034] Similarly, the lowest temperature that an optical connector can withstand under normal operating conditions. The process of obtaining the temperature can also be carried out in the manner described above, ultimately yielding the highest temperature at which the optical connector can function normally. ,in, It is a natural number.

[0035] Based on this, the extreme temperature range within which the product can be used normally can be calculated:

[0036] In the formula, This refers to the extreme temperature range within which the product can be used normally. The highest temperature at which the product can operate normally; This is the minimum temperature at which the product can function properly.

[0037] More preferably, in actual experiments, to avoid the continued impact on the performance of the optical connector when it exceeds the upper or lower limit of its normal operating temperature, a sample replacement procedure is also set up, namely: When preparing samples, it is preferable to prepare multiple optical connectors from the same batch for later use. If the previous sample fails to work properly at the experimental temperature, after adjusting the temperature, replace it with another untested sample to participate in subsequent experiments. This avoids the irreversible influence of the previous experiment on the experimental results and fully ensures the accuracy of the experimental results.

[0038] (3) Construct a temperature-accelerated aging assessment model for vehicle-mounted optical connectors; Based on the fatigue failure principle under alternating temperature stress, the product of the failure cycle number and the power of the plastic strain generated in each cycle is defined as a constant. The formula is expressed as: (Formula 1) In the formula, This represents the number of loops before the failure. The plastic strain for each cycle, which is related to the temperature difference. It exhibits a linear relationship, that is ,in, is the coefficient of thermal expansion.

[0039] Based on the aforementioned formula, the acceleration factor under temperature cycling It can be converted into: (Formula 2) In the formula, This represents the number of cycles before product failure under normal operating conditions. To accelerate the number of product cycles before failure during aging cycles; To accelerate the difference between the highest and lowest temperatures during aging cycles; This represents the average temperature difference during a day's working hours under normal operating conditions. The acceleration constant is independent of temperature. Different failure types of products correspond to different values, which are generally between 1 and 8.

[0040] Furthermore, the lifespan of optical connectors is directly related to the temperature variation they experience. During accelerated aging cycles, a higher accelerated temperature difference is crucial. Corresponding to the expected lifetime during equivalent accelerated testing Under normal operating conditions, the product's expected lifespan Difference in average temperature from normal operating conditions Corresponding. That is: (Formula 3) At the same time, for specific products, its and Given a fixed value, the above formula can be transformed to obtain: (Formula 4) In the formula, It is a constant, and ; and They exhibit a linear correlation.

[0041] Based on the above-mentioned relationships, in a preferred embodiment, the constants in the aforementioned temperature-accelerated aging model are... The determination of the optimal value is obtained through the following process: (3.1) Select multiple standard samples of vehicle-mounted optical connectors and assemble them into experimental wire harnesses for later use; (3.2) Set the system's permissible threshold for judging the failure of standard samples; For example, in a preferred embodiment, the insertion loss change of 0.2 dB (the change before and after the experiment or the instantaneous change) is used as the system's allowable threshold for the entire lifetime of a single standard sample. That is, once the change in the measurement result of the standard sample under test exceeds the aforementioned system allowable threshold, the standard sample is determined to have failed, and the number of cycles experienced is the lifetime of the sample under accelerated experimental conditions; More specifically, when selecting the system's permissible threshold, it generally corresponds to the actual permissible threshold, which is typically determined based on the attenuation margin of the automotive fiber optic link. However, due to constants... This is a fixed value, independent of the accelerating temperature difference and the system's allowable threshold for failure detection. Typically, this is done to shorten the constant value. The experimental determination time is used, and the system allows a threshold value that is preferably less than the loss change value when the optical connector is actually determined to be faulty.

[0042] More preferably, it is 1 / 5 to 1 / 4 of the failure threshold for the optical connector in actual experiments. That is, corresponding to the aforementioned loss change of 0.2dB, the loss change for determining optical connector failure in actual experiments is 0.8dB to 1.0dB.

[0043] (3.3) Set the temperature cycling range for the standard samples ; In actual experiments, the temperature cycling range This includes multiple different temperature cycling ranges. Specifically, the temperature cycling range is set for experiments on standard samples. Preferred includes , , ,in, Select the temperature difference value, such as 10℃, 20℃, or 30℃.

[0044] At the same time, when narrowing the temperature cycling range, it is preferable to narrow it simultaneously from both ends of the temperature range toward the middle, that is... The scope of reference is: ~ ; The scope of reference is: ~ .

[0045] Of course, when the temperature cycling range When other changes occur, the upper and lower limits of the temperature range can be determined in the same way, and will not be elaborated here.

[0046] (3.4) Set up several standard samples under each temperature cycle condition to conduct experiments and test the life cycle of each standard sample; In actual setup, the optical loss change of each standard sample is detected online until the optical loss change of the standard sample reaches the system's allowable threshold.

[0047] More specifically, it is preferable to set up multiple standard samples for experiments under the same temperature cycling conditions, and take the average value of the final measured life cycle as the test result under the temperature cycling conditions.

[0048] (3.5) Combined with (Formula 4), calculate the parameters under accelerated experiment. and The parameters were obtained by fitting using the least squares method. and The linear relationship between them ultimately yields the constant. The value of . Based on the aforementioned design process, the constants in the temperature-accelerated aging evaluation model for standard optical connector samples can be accurately obtained. .

[0049] (4) Construct a vibration-accelerated aging assessment model for vehicle-mounted optical connectors; Similar to the aforementioned temperature-accelerated aging assessment model, the product lifespan of automotive optical connectors is directly related to the vibration changes they experience. A vibration-accelerated aging assessment model satisfying the following relationship was constructed: (Formula 5) In the formula, The expected lifespan of the product under normal operating conditions; The expected lifespan of the product when undergoing equivalent accelerated testing; This represents the root mean square value of vibration acceleration under actual service conditions. This represents the root mean square value of vibration acceleration under equivalent acceleration experimental conditions. This represents the acceleration power spectral density under actual service vibration conditions. This represents the acceleration power spectral density corresponding to the equivalent accelerated vibration experiment. This represents the fatigue index.

[0050] Regarding the fatigue index in the aforementioned model Its value is usually selected based on industry experience. More specifically, for welded structures, the fatigue index... The value of is generally taken as 3; for non-welded structures, the fatigue index is... The value is generally between 4 and 8. Since the vehicle-mounted optical connector is a non-welded structure, a conservative value within the range can be used as needed, typically 4.

[0051] Furthermore, the root mean square value of vibration acceleration under equivalent acceleration conditions was also determined. The acquisition process: (4.1) Setting the equivalent acceleration experiment temperature conditions Based on the determination of the constant C, and combined with (Formula 2), the acceleration factor is obtained. Temperature range under equivalent acceleration experiment The correspondence between them.

[0052] In actual setup, to save testing time, it is preferable to select... Temperature conditions used in equivalent accelerated experiments.

[0053] (4.2) Combined with (Formula 5), ​​calculate the equivalent accelerated experimental temperature conditions. The root mean square value of vibration acceleration under the following conditions .

[0054] Combined with the acceleration factor at this time Substituting the calculation results into (Equation 5), the root mean square value of the vibration acceleration under the equivalent acceleration condition can be obtained. .

[0055] (4.3) Determine the measured root mean square value of vibration acceleration Does it meet the experimental requirements? If not, change it. The value is taken and the process (4.1) to (4.3) is repeated.

[0056] Specifically, Maximum acceleration value of laboratory vibration equipment Compare; if This indicates that the equipment's capabilities were not exceeded and the selected temperature conditions met the experimental requirements. In this case, the acceleration factor can be used. Accelerating the experimental temperature range Root mean square value of vibration acceleration Conduct a three-dimensional vibration experiment. If... This accelerates the experimental temperature range. This indicates that the test limits of the vibration equipment have been exceeded. In this case, the following can be selected: As the temperature condition for the equivalent accelerated experiment, the acceleration factor is calculated. Root mean square value of vibration acceleration Until the measured root mean square value of vibration acceleration. Conditions met: .

[0057] (5) Determine the accelerated testing conditions for the vehicle-mounted optical connector; the accelerated testing conditions shall at least include the temperature cycling range during the testing of the optical connector samples. Limiting temperature holding time, rate of temperature change, vibration conditions (root mean square value of vibration acceleration) ) and the theoretical number of cycles for accelerated experiments .

[0058] Specifically, the holding time at the extreme temperature in accelerated experimental conditions is generally related to the material, type, and volume of the sample. It refers to the time required for the sample (especially fiber optic connector assemblies with a certain volume and complex internal structure) to change from the initial temperature to the target temperature. In actual experiments, heat transfer needs to be completed step by step from the outer shell to the internal core components (such as ceramic ferrules, adhesives, and metal parts) to achieve the physical basis of thermal equilibrium. For the extreme temperature holding time in the preferred embodiment, it should ensure that the sample reaches thermal equilibrium inside and out. More preferably, the extreme temperature holding time in the preferred embodiment is 30 minutes. At this time, it can ensure that the optical connector reaches the empirical value of uniform internal and external temperature and thermal stability, and ensure that the test temperature stress can be applied to every part of the product in a true and sufficient manner, thereby exposing potential defects such as material mismatch and differences in coefficient of thermal expansion.

[0059] Secondly, the determination of the rate of temperature change mainly considers the following points: (1) Simulating real environmental changes: Under natural conditions, temperature changes are usually slow, with a rate of approximately 0.5℃ / min to 2℃ / min. The 1℃ / min rate in the preferred embodiment is a representative, compromise rate that can better simulate such actual temperature change conditions.

[0060] (2) The “slow change” rate of 1℃ / min allows stress to gradually accumulate and be released inside the product, which can more effectively expose chronic defects such as bonding failure, crack propagation, and poor contact. This is the key to assessing the long-term reliability of optical connectors.

[0061] (3) Compatible with existing equipment capabilities; the most common engineering and quality control test chambers on the market can meet the temperature change rate requirement of 1℃ / min.

[0062] More preferably, the determination of vibration conditions can be made by changing the temperature cycling range, based on the description in process (4) and in combination with (Formula 5). The value of is used to determine the vibration conditions corresponding to different temperature cycling ranges (i.e., the root mean square value of vibration acceleration for each temperature cycling range). The vibration conditions and temperature cycling range were obtained. A correspondence table between them. Thus, when conducting accelerated aging cycle tests on subsequent optical connectors, the maximum acceleration value of the vibrating equipment can be used as a reference. Quickly determine the temperature cycling range for accelerated aging tests on optical connectors.

[0063] (6) Based on the aforementioned accelerated experimental conditions, accelerated life assessments were conducted on various batches of the same type of automotive optical connectors to determine whether their cycle life met the theoretical lifespan. Specifically, the determination was based on: Under the same equivalent accelerated testing conditions, does the number of test cycles for the optical connector exceed the theoretical number of cycles? Or the theoretical number of cycles Whether the difference in the number of times between them is within the set threshold.

[0064] It is understandable that the “vehicle optical connector” used in steps (1) to (5) is actually a standard sample of this type of vehicle optical connector, that is, a standard part. It is assumed that the quality control quality of the same batch of standard samples is consistent. By using the design of the corresponding accelerated aging model and the design of steps (1) to (5), the accelerated test conditions of this type of vehicle optical connector can be completed based on the standard sample, and then used as the test condition benchmark for the accelerated aging test of the vehicle optical connector under test, so as to judge the quality difference (cycle life difference) of the vehicle optical connector under test compared with the standard sample.

[0065] More specifically, when determining the accelerated experimental design, a control experimental group was also preferred.

[0066] As an example, a corresponding number of connector samples were selected and tested under normal temperature and vibration conditions to detect whether the optical connector under normal conditions would fail when the optical connector failed under accelerated aging test.

[0067] As another example, multiple optical cable samples identical to those used in the accelerated aging test for connecting the vehicle-mounted optical connector were selected. After protecting the ends of the optical cables, they were placed under the same experimental conditions as the accelerated aging test. When the accelerated aging test of the vehicle-mounted optical connector determined that it had failed, a continuity test was performed on the optical cables.

[0068] In fact, conventional optical cables generally have a much stronger ability to withstand temperature and vibration than optical connectors. Therefore, the failure results of accelerated aging tests of optical connectors can be correlated with the failure of optical connectors.

[0069] More specifically, the performance of optical connector samples after accelerated aging tests is evaluated. If the performance meets the requirements, it indicates that the optical connector harness meets the expected service life. The specific evaluation criteria are as follows: The additional attenuation of the vehicle-mounted optical cable is no greater than 0.2dB (for the case where the optical cable is set up separately for aging test in the preferred embodiment); in the experiment, the additional attenuation of the vehicle-mounted optical connector sample (including optical connector and optical cable bundle) is no greater than 0.6dB, and there is no transient interruption of more than 1 microsecond; and after the experiment (after removing the temperature aging condition and vibration aging condition), the additional attenuation of the vehicle-mounted optical connector sample is no greater than 0.3dB.

[0070] The accelerated life assessment method for the aforementioned vehicle-mounted optical connector will be further illustrated and explained below through a specific embodiment.

[0071] In this embodiment, the selected automotive optical connector has a PBT or PPS plastic shell and a zirconia ceramic ferrule. The process for determining its accelerated aging test conditions is as follows: (1) Determine the extreme temperature range that the connector material can withstand. The temperature range is 200℃, which is -50℃ to +150℃.

[0072] (2) Determine the maximum operating temperature range within which the optical connector can function normally based on the transmission performance evaluation at a specific temperature point. The temperature range is 165℃, which is -40℃ to +125℃.

[0073] (3) After the temperature accelerated aging assessment model of the component vehicle optical connector, the value of the constant C is calculated.

[0074] Specifically, in actual use, this optical connector undergoes two temperature cycles per day, with a total product lifespan expected to be 15 years, and the average temperature change is... The temperature is 40°C.

[0075] right The experiment was conducted at 165°C, 145°C, and 125°C, and the final value of the constant C was 2.5.

[0076] (4) Determine appropriate accelerated aging test parameters.

[0077] The product lifecycle of this automotive optical connector is expected to be 15 years, with an average temperature variation of [missing information]. The product testing temperature cycling range is 40°C. Set to maximum normal operating temperature range (i.e., -40℃ to +125℃), that is It equals 165°C.

[0078] At this point, the acceleration factor is: ; The number of cycles within a 15-year product lifecycle is: (Second-rate); The number of cycles in the accelerated aging test was: (Second-rate); Based on the product characteristics, the heating and cooling rate under experimental conditions is 1℃ / min, and the extreme temperature is maintained for 30 minutes, resulting in a single cycle time of 6.5 hours. It should be noted that a single cycle here refers to the process of continuously changing the temperature from one extreme temperature to another, and then continuously changing the temperature back to the initial extreme temperature.

[0079] For example, in this embodiment, starting from the lowest temperature as the initial temperature, the product is placed at -40°C and held for 30 minutes. Then, the temperature is increased at a rate of 1°C / min until it reaches +125°C; subsequently, it is held at +125°C for 30 minutes. Afterward, the temperature is decreased at a rate of 1°C / min until it reaches -40°C. One cycle is completed, taking approximately (30 + 165 + 30 + 165) minutes, totaling 6.5 hours.

[0080] Based on this, the total experimental time under accelerated aging test is: .

[0081] Furthermore, the vibration parameters of the optical connector sample were determined.

[0082] Under actual service conditions, the root mean square value of vibration acceleration 15m / s 2 According to Formula 5, the root mean square value of vibration acceleration under equivalent acceleration test conditions is calculated. for: (m / s) 2 ).

[0083] At this point, only the maximum acceleration value of the laboratory's vibration equipment is needed. Greater than the above A value that satisfies the experimental conditions is sufficient for the test. In this embodiment, the maximum acceleration of the laboratory vibration equipment can reach 50g, or 500 m / s². 2 The experimental conditions are met.

[0084] In summary, the experimental scheme for this type of vehicle-mounted optical connector can be determined as follows: Temperature range: -40℃ to +125℃ The temperature rise and fall rate of the test environment chamber is 1℃ / min; the extreme temperature is maintained for 30min. Accelerated aging test cycle ; Root mean square value of vibration acceleration m / s 2 (Approximately 690 hours in each of the X / Y / Z directions).

[0085] Under the above test conditions, the same type of automotive optical connector can be tested, and the measured number of cycles under accelerated aging test conditions can be compared with the expected value. (Time) A comparison is made. If the value is not lower than the expected value or the difference between the value and the expected value is within the predetermined range, it indicates that the tested vehicle optical connector meets the design requirements; otherwise, it does not meet the requirements.

[0086] The accelerated life assessment method for automotive optical connectors in this invention is simple in steps and easy to use. It can accelerate the assessment of the cycle life of automotive optical connectors, ensuring the accuracy of the cycle life assessment while shortening the cycle life testing time. It provides conditions for determining the cycle life of automotive optical connectors at different stages of finalization and for rapid sampling inspection after mass production. It supports the promotion and application of automotive optical connectors, promotes their application in automotive environments, and has excellent application prospects.

[0087] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for accelerating the lifetime assessment of an automotive optical connector, characterized in that, Includes the following steps: (1) Determine the extreme temperature range that the material of the vehicle-mounted optical connector can withstand; (2) Determine the extreme operating temperature range within which the vehicle-mounted optical connector can function normally; (3) Construct a temperature-accelerated aging evaluation model for automotive optical connectors and characterize it as follows: (Formula 1) (Official 2) (Official 3) (Official 4) In the formula, This represents the number of loops before the failure. Plastic strain for each cycle; This represents the number of cycles before product failure under normal operating conditions. To accelerate the number of product cycles before failure during aging cycles; To accelerate the difference between the highest and lowest temperatures during aging cycles; This represents the average temperature difference during a day's working hours under normal operating conditions. The acceleration constant is independent of temperature. The expected lifetime during equivalent accelerated experiments; The expected lifespan of the product under normal operating conditions; It is a constant; (4) Construct a vibration-accelerated aging assessment model for vehicle-mounted optical connectors and characterize it as follows: (Official 5) In the formula, This represents the root mean square value of vibration acceleration under actual service conditions. This represents the root mean square value of vibration acceleration under equivalent acceleration experimental conditions. This represents the acceleration power spectral density under actual service vibration conditions. This represents the acceleration power spectral density corresponding to the equivalent accelerated vibration experiment. The fatigue index; (5) Determine the accelerated testing conditions for the vehicle-mounted optical connector; the accelerated testing conditions shall at least include the temperature cycling range during the testing of the optical connector samples. Limit temperature holding time, rate of temperature change, and root mean square value of vibration acceleration. And the theoretical number of cycles for accelerating the experiment. ; (6) Accelerated lifetime assessment of the vehicle-mounted optical connector under test is performed according to the accelerated test conditions.

2. The accelerated life assessment method for automotive optical connectors according to claim 1, characterized in that, In step (2), the process for determining the extreme operating temperature range within which the optical connector can function normally is as follows: (2.1) Connect the vehicle-mounted optical connector sample to the test optical path; (2.2) Place the vehicle-mounted optical connector sample at the highest temperature that the material can withstand. and lowest temperature The temperature reaches thermal equilibrium and remains at that point for a certain period of time. (2.3) Monitor the transmission performance of the optical connector at the above two temperatures; if the optical performance of the optical connector does not meet the requirements at a certain extreme temperature, adjust its operating temperature to a certain value within the range. And based on this, the product's transmission performance was tested again until the highest temperature at which the optical connector could operate normally was finally obtained. and lowest temperature .

3. The accelerated life assessment method for automotive optical connectors according to claim 2, characterized in that, Adjusting the temperature The values ​​are 5℃, 10℃, 15℃, or 20℃; and / or Adjusting the temperature During the subsequent sample testing process, another optical connector sample that had not participated in the experiment was used in the subsequent experiments.

4. The accelerated life assessment method for automotive optical connectors according to any one of claims 1 to 3, characterized in that, In step (3), the acceleration constant The acquisition process is as follows: (3.1) Select multiple standard samples of vehicle-mounted optical connectors and assemble them into experimental wire harnesses for later use; (3.2) Set the system's permissible threshold for judging the failure of standard samples; (3.3) Set the temperature cycling range for the standard samples Among them, the temperature cycling range Includes multiple different temperature cycling ranges; (3.4) Experiments were conducted on the standard samples under each temperature cycling condition to test the life cycle of each standard sample; (3.5) Combined with (Formula 4), calculate the parameters under accelerated experiment. and And fit the parameters to obtain and The linear relationship between them ultimately yields the constant. The value of .

5. The accelerated life assessment method for automotive optical connectors according to claim 4, characterized in that, In process (3.3), the temperature cycling range include , , ,in, This refers to the extreme temperature range within which the product can be used normally. The selected temperature difference value.

6. The accelerated life assessment method for automotive optical connectors according to claim 5, characterized in that, In step (4), the root mean square value of vibration acceleration under equivalent acceleration conditions The acquisition process is as follows: (4.1) Setting the equivalent acceleration experiment temperature conditions Based on the determination of the constant C, and combined with (Formula 2), the acceleration factor is obtained. and The correspondence between them; (4.2) Combined with (Formula 5), ​​calculate the equivalent accelerated experimental temperature conditions. The root mean square value of vibration acceleration under the following conditions ; (4.3) Determine the measured root mean square value of vibration acceleration Does it meet the experimental requirements? If not, change it. The value is taken and the process (4.1) to (4.3) is repeated.

7. The accelerated life assessment method for automotive optical connectors according to claim 6, characterized in that, When determining the vibration conditions in step (5), the temperature cycling range is changed according to processes (4.1) to (4.2). The value of is used to determine the vibration conditions corresponding to different temperature cycling ranges, thus obtaining the vibration conditions and temperature cycling ranges. A table showing the correspondence between them.

8. The accelerated life assessment method for automotive optical connectors according to any one of claims 1-3 and 5-7, characterized in that, Based on the accelerated test conditions determined in step (5), accelerated life assessment tests are conducted on the same type of vehicle-mounted optical connectors to determine whether their cycle life meets the theoretical life cycle; the basis for the determination is: Under the same equivalent accelerated testing conditions, does the number of test cycles for the optical connector exceed the theoretical number of cycles? Or the theoretical number of cycles Whether the difference in the number of times between them is within the set threshold.

9. The accelerated life assessment method for automotive optical connectors according to claim 8, characterized in that, When conducting accelerated life assessment tests on automotive optical connectors, the criteria for determining whether an automotive optical connector has failed are as follows: During the experiment, the additional attenuation of the vehicle-mounted optical connector sample was no greater than 0.6 dB, and there was no transient interruption of more than 1 microsecond; and after the experiment, the additional attenuation of the vehicle-mounted optical connector sample was no greater than 0.3 dB.

10. The accelerated life assessment method for automotive optical connectors according to any one of claims 1-3, 5-7, and 9, characterized in that, A control group was also designed: Multiple optical cable samples identical to those used in the accelerated aging test for connecting the vehicle-mounted optical connector were selected. After protecting the ends of the optical cables, they were placed under the same test conditions as the accelerated aging test. When the accelerated aging test of the vehicle-mounted optical connector determined that it had failed, the optical cables were subjected to a continuity test.

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