A transmission durability test method, system, storage medium, and device

Abstract

The application provides a transmission durability test method, system, storage medium and equipment, and relates to the technical field of automobile test.The method obtains the change course of the speed-torque of each gear of the transmission with time in the form of vehicle dynamics simulation in the durability simulation working condition by establishing a vehicle dynamics model and a road topology model, quickly calculates and evaluates the root tooth fracture durability damage DV value and the tooth surface pitting durability damage DV value of each gear in the form of Duty value (DV), obtains the test load spectrum of each gear through the DV value iterative solution mode according to the required sample size of the test designed according to the reliability target of the vehicle manufacturer and the DV value of the single test transmission, and performs the durability test on the transmission based on the test load spectrum to meet the durability issue condition of the test.

Description

Technical Field

[0001] This invention relates to the field of vehicle testing technology, and in particular to a method, system, storage medium, and equipment for testing the durability of a transmission. Background Technology

[0002] Typically, domestic transmission manufacturers use the national recommended standard durability specification (QCT 568.1 Bench Test Method for Automotive Mechanical Transmission Assembly) to verify the durability of rotating components such as gears, shafts, and bearings in the transmission. However, the load spectrum of these specifications is only related to the engine's maximum torque and cannot accurately reflect the impact of vehicle parameters (vehicle weight, tire rolling radius, etc.) and overall vehicle durability conditions on the transmission's durability. Therefore, using the national recommended standard durability specification often results in insufficient or over-verification of testing, leading to design flaws or over-design in components.

[0003] Therefore, obtaining a reliable load spectrum for the transmission that accurately reflects the vehicle's durability is crucial. Furthermore, the design and development of the transmission load spectrum takes into account the vehicle manufacturer's reliability requirements, guiding the transmission's test design and pricing in the early stages of vehicle project development. Summary of the Invention

[0004] Based on this, the purpose of the present invention is to provide a transmission durability testing method, system, storage medium and equipment, which aims to solve the problem that the transmission durability test in the prior art cannot truly reflect the influence of vehicle parameters (vehicle weight, tire rolling radius, etc.) and vehicle durability conditions on the transmission durability.

[0005] A first aspect of the present invention is to provide a method for testing the durability of a transmission, the method comprising:

[0006] Based on the vehicle design parameters of the target vehicle, establish the vehicle dynamics model of the target vehicle;

[0007] According to the preset rules of the vehicle durability test specification, road topology modeling is performed based on the site information of the target test site to obtain the road topology model;

[0008] According to the preset rules of the vehicle durability test specification, the vehicle dynamics model is imported into the road topology model for durability condition simulation, and the durability condition simulation results are output.

[0009] Based on the endurance simulation results, the input shaft information of the transmission is obtained, and the number of cycles of each gear of the transmission in each preset torque range is determined according to the input shaft information, so as to determine the original load spectrum of the transmission.

[0010] Based on the original load spectrum, the DV value of each gear in the transmission is calculated to determine the durability target of the transmission.

[0011] Based on the vehicle manufacturer's reliability requirements, the test sample size, and the limit DV values ​​of each gear of the transmission, the actual test sample size required for the transmission and the durability target value for the extended test are calculated iteratively.

[0012] Based on the durability target value, the test load spectrum for the transmission is iteratively calculated to conduct bench durability tests on the transmission according to the test load spectrum.

[0013] According to one aspect of the above technical solution, in the step of establishing a vehicle dynamics model of the target vehicle based on the vehicle design parameters of the target vehicle, the vehicle dynamics model includes an engine model, a transmission model, a tire model, and a vehicle model.

[0014] According to one aspect of the above technical solution, the step of obtaining the input shaft information of the transmission based on the durability simulation results, and determining the number of cycles of each gear of the transmission in each preset torque range based on the input shaft information, so as to determine the original load spectrum of the transmission, specifically includes:

[0015] Based on the simulation results of the whole vehicle durability condition of the target vehicle, the input shaft information of the transmission and the gear information of the gearbox are obtained; wherein, the input shaft information includes at least the speed and torque of the input shaft;

[0016] Based on the input shaft information and gear information of the transmission, determine the number of cycles of each gear in each preset torque range;

[0017] The number of cycles is determined as the original load spectrum of the transmission; wherein the original load spectrum is the load spectrum executed when the historical transmission was tested.

[0018] According to one aspect of the above technical solution, in the step of iteratively calculating the actual test sample size required for the transmission and the durability target value for the extended test, based on the vehicle manufacturer's reliability requirements, the test sample size, and the limit DV values ​​of each gear of the transmission:

[0019] The expression for calculating gear contact fatigue damage is:

[0020]

[0021] The expression for calculating tooth root bending fatigue damage is:

[0022]

[0023] In the formula, N D, σ D , m are constants related to the specimen material, and α1 and α2 are constants related to gear design.

[0024] According to one aspect of the above technical solution, DV H With DV F The dimensionless value used to characterize gear contact fatigue damage and tooth root bending fatigue damage is directly proportional to the gear's input torque and rotational speed.

[0025] According to one aspect of the above technical solution, in the formula, k1 = 3 and k2 = 6.

[0026] A second aspect of the present invention is to provide a gearbox durability testing system, the system comprising:

[0027] The first modeling module is used to establish the vehicle dynamics model of the target vehicle based on the vehicle design parameters of the target vehicle.

[0028] The second modeling module is used to perform road topology modeling based on the site information of the target test site according to the preset rules of the whole vehicle durability test specification to obtain the road topology model.

[0029] The durability test module is used to import the vehicle dynamics model into the road topology model for durability condition simulation according to the preset rules of the vehicle durability test specification, and output the durability condition simulation results.

[0030] The information acquisition module is used to acquire the input shaft information of the transmission based on the endurance condition simulation results, so as to determine the number of cycles of each gear of the transmission in each preset torque range based on the input shaft information, so as to determine the original load spectrum of the transmission.

[0031] The first calculation module is used to calculate the DV value of each gear of the transmission based on the original load spectrum, so as to determine the durability target of the transmission.

[0032] The second calculation module is used to iteratively calculate the actual test sample size required for the transmission and the durability target value for extended testing based on the vehicle manufacturer's reliability requirements, the test sample size, and the limit DV value of each gear of the transmission.

[0033] The third calculation module is used to iteratively calculate the test load spectrum of the transmission for testing based on the durability target value, so as to conduct bench durability testing on the transmission based on the test load spectrum.

[0034] According to one aspect of the above technical solution, the information acquisition module is specifically used for:

[0035] Based on the simulation results of the whole vehicle durability condition of the target vehicle, the input shaft information of the transmission and the gear information of the gearbox are obtained; wherein, the input shaft information includes at least the speed and torque of the input shaft;

[0036] Based on the input shaft information and gear information of the transmission, determine the number of cycles of each gear in each preset torque range;

[0037] The number of cycles is determined as the original load spectrum of the transmission; wherein the original load spectrum is the load spectrum executed when the historical transmission was tested.

[0038] A third aspect of the present invention is to provide a computer-readable storage medium having computer instructions stored thereon, which, when executed by a processor, implement the steps of any of the methods described in the above-described technical solutions.

[0039] A fourth aspect of the present invention is to provide a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps of any of the methods described above.

[0040] Compared with the prior art, the advantages of using the transmission durability testing method, system, storage medium and equipment shown in this invention are as follows:

[0041] This invention establishes a vehicle dynamics model and a road topology model. Under durability simulation conditions, it obtains the time-varying history of the speed-torque of each gear of the transmission in the form of vehicle dynamics simulation. By using the Dutyvalue (DV) method, it quickly calculates and evaluates the DV value of tooth root fracture durability damage and tooth surface pitting durability damage for each gear. Based on the reliability targets required by the vehicle manufacturer, it designs the sample size required for the test and the DV value of a single test transmission. By iteratively solving the DV value, it obtains the test load spectrum for each gear. Then, based on the test load spectrum, it conducts a durability test on the transmission to meet the durability issuance conditions of the test. Attached Figure Description

[0042] Figure 1 This is a flowchart illustrating the transmission durability test method in the first embodiment of the present invention;

[0043] Figure 2 This is a schematic diagram of the durability condition simulation results completed in step S30 of the first embodiment of the present invention;

[0044] Figure 3 This is a schematic diagram of the original load spectrum of the transmission extracted in step S40 of the first embodiment of the present invention;

[0045] Figure 4This is a schematic diagram of the DV values ​​of the original load spectrum in step S50 of the first embodiment of the present invention;

[0046] Figure 5 This is a schematic diagram of the load spectrum adjustment strategy in step S70 of the first embodiment of the present invention;

[0047] Figure 6 This refers to the load spectrum of the first gear ultimately applied to the test bench in step S70 of the first embodiment of the present invention;

[0048] Figure 7 This is a structural block diagram of the transmission durability testing system in the second embodiment of the present invention;

[0049] The following detailed description of the embodiments will further illustrate the present invention in conjunction with the above-described accompanying drawings. Detailed Implementation

[0050] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Several embodiments of the invention are illustrated in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

[0051] Example 1

[0052] Please see Figures 1-6 The above is a flowchart illustrating a transmission durability testing method according to the first embodiment of the present invention, the method comprising steps S10-S70:

[0053] Step S10: Based on the vehicle design parameters of the target vehicle, establish the whole vehicle dynamics model of the target vehicle.

[0054] Specifically, the design parameters of the target vehicle include the design parameters of various components of the vehicle, such as the length, width, height of the body, and the density of the materials required. Based on these design parameters, a whole vehicle dynamics model of the target vehicle is established, which includes the engine model, transmission model, tire model, and whole vehicle model. It should be noted that the whole vehicle model is the frame model excluding the engine model, transmission model, and tire model.

[0055] Step S20: According to the preset rules of the vehicle durability test specification, road topology modeling is performed based on the site information of the target test site to obtain the road topology model.

[0056] Specifically, in accordance with the requirements of the vehicle durability test specifications, the target test site information is used to perform road topology modeling. The site information of the target test site includes the test site length, slope, slope length, turning radius and speed limit, etc. In other words, a simulation model for vehicle durability testing is generated based on the above site information.

[0057] Step S30: According to the preset rules of the vehicle durability test specification, import the vehicle dynamics model into the road topology model for durability condition simulation and output the durability condition simulation results.

[0058] Specifically, by importing the vehicle dynamics model into the road topology model, dynamic durability simulation of the vehicle dynamics model can be performed in the road topology model. Users can then monitor the durability simulation through display devices such as computers, thereby controlling the progress of the durability simulation.

[0059] The durability simulation results include at least simulation time information and simulation vehicle information. The simulation vehicle information includes various operating parameters of the engine system and transmission system, such as speed and temperature.

[0060] In this embodiment, the established vehicle dynamics model can be stored as a file or a plugin. Similarly, the established road topology model can also be stored as a file or a plugin. Taking the plugin format as an example, in a preset simulation system, the vehicle dynamics model and the road topology model in plugin format can be imported simultaneously, and then the parameters can be set. This allows for durability simulation of the vehicle dynamics model using the road topology within the simulation system.

[0061] Step S40: Based on the endurance simulation results, obtain the input shaft information of the transmission, and determine the number of cycles of each gear of the transmission in each preset torque range based on the input shaft information, so as to determine the original load spectrum of the transmission.

[0062] Specifically, the acquired input shaft information of the transmission includes the speed and torque information of the input shaft. The number of cycles of each gear of the transmission in each preset torque range during the endurance simulation can be determined by the speed and torque information of the transmission input shaft. The original load spectrum of the transmission can then be determined based on the number of cycles of each gear of the transmission in each preset torque range during the endurance simulation.

[0063] In this embodiment, the step of obtaining the input shaft information of the transmission based on the durability simulation results, and determining the number of cycles of each gear of the transmission in each preset torque range based on the input shaft information, in order to determine the original load spectrum of the transmission, specifically includes steps S41-S43:

[0064] Step S41: Based on the vehicle durability simulation results of the target vehicle, obtain the input shaft information of the transmission and the gear information of the gearbox; wherein, the input shaft information includes at least the rotational speed and torque of the input shaft;

[0065] Step S42: Based on the input shaft information and gear information of the transmission, determine the number of cycles of each gear in each preset torque range of the transmission;

[0066] Step S43: Determine the number of cycles as the original load spectrum of the transmission; wherein the original load spectrum is the load spectrum executed when the historical transmission was tested.

[0067] The purpose of determining the original load spectrum of the transmission in this embodiment is to optimize the original load spectrum so that the durability test of the transmission can be carried out based on the optimized load spectrum in the later stage; of course, this is also the ultimate goal of the present invention.

[0068] In this embodiment, steps S50-S70 are used to achieve the purpose of conducting a durability simulation test on the transmission using the optimized load spectrum.

[0069] Step S50: Calculate the DV value of each gear in the transmission based on the original load spectrum to determine the durability target of the transmission;

[0070] It should be noted that the DV (Duty Value) is the cumulative damage value, which in this embodiment refers to the cumulative damage value of each gear in the transmission. The damage to the gears includes tooth surface damage and tooth root damage, such as gear scratches. This method simplifies the calculation process for tooth root breakage damage and tooth surface pitting damage. Based on Miner's damage accumulation theory, a rapid calculation method for transmission gear damage, namely the DV value calculation method, is proposed. The DV values ​​for tooth root damage and tooth surface damage of each gear are then calculated as the durability target for the transmission's 100% lifespan.

[0071] In this embodiment, the steps for calculating the DV value of each gear in the transmission are as follows:

[0072] First, based on the linear damage accumulation theory, the calculation method for the DV value is derived: According to fatigue strength theory, the equation for the oblique part of the SN curve is σ. m N = constant, therefore:

[0073]

[0074] In the formula, σ i For the stress level of the specimen under various working conditions, N i σ represents the number of cycles required for the test to proceed until the part fails under various stresses. D The stress level during specimen testing, N DTo test the number of cycles required for specimen failure under stress, m is a constant determined by the material, and is the negative value of the reciprocal of the slope of the SN curve in a double logarithmic coordinate system.

[0075] The damage to the specimen after a number of cycles under arbitrary stress can be expressed as follows:

[0076]

[0077] In the formula, n i For any stress σ i The number of cycles is given below, and d represents the corresponding damage.

[0078] By combining formulas (1-2), we can obtain:

[0079]

[0080] According to the gear calculation standard (ISO 6336-6-2006), the expressions for the contact stress and tooth root bending stress of a gear are as follows:

[0081]

[0082]

[0083] In the formula, σ Hi For tooth surface contact stress, σ Fi For the bending stress at the tooth root, T i Z is the input torque of the gear. H Z E Z ε Z β Z BD ,u,d i b, Z Vi Z Hβi Z Hαi m n Y F Y s Y β K Vi K Fβi and K Fαi These are all parameters related to gear design.

[0084] When calculating the stress magnitude of the same pair of gears under different input torques, these parameters are all constants. For ease of derivation, these gear design-related coefficients are represented by α1 and α2 respectively:

[0085]

[0086] σ Fi =α2T i (7)

[0087] Substituting equations (6) and (7) into equation (3) respectively, we obtain the contact fatigue damage d of the gear tooth surface. H and tooth root bending fatigue damage d F They are respectively:

[0088]

[0089]

[0090] In the formula, m1 and m2 are the negative values ​​of the reciprocals of the slopes of the SN curves for tooth surface contact fatigue damage and tooth root bending fatigue damage, respectively. After simplification, we get:

[0091]

[0092]

[0093] In the formula, N D , σ D , where m are constants related to the specimen material, and α1 and α2 are constants related to gear design. Therefore, DV H and DV F This method provides a dimensionless value characterizing gear contact fatigue damage and tooth root bending fatigue damage, which is directly proportional to the gear's input torque and rotational speed. Typically, k1 = 3 and k2 = 6 are chosen to characterize tooth surface contact fatigue damage and tooth root bending fatigue damage, respectively. The advantage of this method is that for the same pair of gears, damage calculation under different operating conditions only requires the gear's input torque and the number of cycles to determine the damage. It can be used for lateral comparisons of gear contact fatigue damage and tooth root bending fatigue damage under different operating conditions. Since it does not require inputting gear-related design parameters, this method greatly simplifies the gear damage calculation process. It can be applied to lateral comparisons of fatigue damage of gears in the same transmission under different loads, as well as damage equivalence processing of load spectra.

[0094] The calculated DV values ​​of the load spectrum in this example are shown below. Figure 4 It calculates the DV during each gear's drive and reverse drag. H and DV F .

[0095] Step S60: Based on the vehicle manufacturer's reliability requirements, the number of test samples, and the limit DV values ​​of each gear of the transmission, iteratively calculate the actual number of test samples required for the transmission and the durability target value for the extended test.

[0096] Specifically, based on the vehicle manufacturer's reliability requirements, the required test sample size and durability target value are calculated. The following example illustrates this using a reliability requirement of 90% reliability and 50% confidence level. When using a 100% test duration t, the reliability formula based on the binomial distribution is as follows:

[0097]

[0098] In the formula, R represents reliability and P represents confidence level. The required sample size for the test can be calculated as n = 6.6 units ≈ 7 units. Therefore, in project development, 7 transmission bench tests need to be defined, with a test duration of 100%, which will significantly increase the development cost of the transmission. Therefore, while ensuring the reliability requirements of the OEM, the test duration should be extended to reduce the number of test samples.

[0099] Combining the Weibull statistical distribution, we can obtain:

[0100]

[0101]

[0102] In the formula, L v To extend the test coefficient, β is the shape parameter of the Weibull statistical distribution of the transmission durability test, t1 is the extended test duration, and 1 is the sample size corresponding to the extended test duration.

[0103] If the desired reliability requirement from the OEM is to be achieved using two test samples, then according to the formula, the test duration for a single unit needs to be extended to t1 = 150%. To prevent failures during testing, it is necessary to assess whether extending the test duration to 150% exceeds the gear's limits. Therefore, the tooth surface contact fatigue damage DV calculated in step 5 will be used... H and tooth root bending fatigue damage DV F Multiply by 1.5, then combine with the maximum DV allowed by each gear of the transmission. Hmax and DV Fmax The comparison is performed. If the maximum permissible value is not exceeded, the durability target for the transmission is confirmed as a 150% durability test. If the maximum permissible value is exceeded, one more sample is added, and the required extended test duration is calculated until DV is reached. H and DV F Less than DV Hmax and DV Fmax .

[0104] Step S70: Based on the durability target value, iteratively calculate the test load spectrum for the transmission used in the test, so as to conduct a bench durability test on the transmission according to the test load spectrum.

[0105] It should be noted that the original load spectrum of the transmission extracted in step S40 contains a large number of operating conditions that require low torque. If the test is conducted according to the original load spectrum, the transmission durability test will take as long as 3-6 months, which increases the test cost and time.

[0106] In this embodiment, the transmission determines that it needs to complete 150% of the test time, which is equivalent to the target single-unit test DV. H and DV F This is 150% of the original load spectrum. Here, the transmission operating condition is divided into drive condition and reverse drag condition. The DV of the drive condition... H and DV F It is 150% of the original load spectrum; among them, the durability damage caused to the transmission by the reverse drag condition is relatively small, but the effect of the reverse drag condition causing the components to be subjected to reverse force cannot be completely ignored. Therefore, in this embodiment, the reverse drag condition is retained for 350,000 cycles.

[0107] Specifically, the iterative processing of the load spectrum is introduced using the first-level working condition as an example. Figure 5 'a' represents the initial load spectrum at level 1, with an input torque ≥ 0 Nm, and a total cycle count of 12,434,170. First, let's look at the DV of the initial load spectrum. F To achieve the target, the number of cycles below 200 Nm (1st gear torque limit) is reduced, and then it is calculated that 548611 cycles are needed to adjust the DV in step S10 to reach 200 Nm. F1 =V F Due to the calculation of DV F and DV H The exponent terms are different (affected by the slope of the SN curve for tooth surface contact fatigue and tooth root bending fatigue), therefore the adjusted DV H1 Only 59.8% of the original load spectrum is represented. This means that adjusting the load spectrum in step S10 achieves consistency with the original load spectrum for tooth root bending fatigue damage; however, only 59.8% of the tooth surface contact fatigue damage is represented, resulting in a loss of 41.2% of the tooth surface contact fatigue damage, leading to insufficient tooth surface verification. Therefore, iterative solutions are needed to simultaneously satisfy… like Figure 5 c. Adjustment step S20. The total number of cycles for gear 1 in adjustment step S20 is 1590197, which is 12.8% of the original number, significantly shortening the test time while preserving the target damage completely. Finally, based on the durability target value obtained in step S60, the final load spectrum for gear 1 is obtained as follows... Figure 6 As shown, this first-stage load spectrum contains 1.5 times the DV. F and DV HThe load spectrum for the reverse drag condition with 350,000 cycles is also designed according to this strategy. Therefore, the final load spectrum only requires two test samples to meet the durability target of 90% reliability and 50% confidence.

[0108] In summary, compared with the prior art, the transmission durability test method shown in this embodiment has the following advantages:

[0109] By establishing a vehicle dynamics model and a road topology model, the speed-torque variation history of each gear of the transmission over time is obtained in the form of vehicle dynamics simulation under durability simulation conditions. By using the duty value (DV) method, the DV value of tooth root fracture durability damage and tooth surface pitting durability damage of each gear is quickly calculated and evaluated. According to the reliability target required by the vehicle manufacturer, the sample size required for the test and the DV value of a single test transmission are designed. The test load spectrum of each gear is obtained by iteratively solving the DV value. Then, based on the test load spectrum, the transmission is subjected to durability test to meet the durability issuance conditions of the test.

[0110] Example 2

[0111] Please see Figure 7 The above is a structural block diagram of a transmission durability testing system according to the third embodiment of the present invention. The system includes:

[0112] The first modeling module 10 is used to establish the whole vehicle dynamics model of the target vehicle based on the vehicle design parameters of the target vehicle.

[0113] Specifically, the design parameters of the target vehicle include the design parameters of various components of the vehicle, such as the length, width, height of the body, and the density of the materials required. Based on these design parameters, a whole vehicle dynamics model of the target vehicle is established, which includes the engine model, transmission model, tire model, and whole vehicle model. It should be noted that the whole vehicle model is the frame model excluding the engine model, transmission model, and tire model.

[0114] The second modeling module 20 is used to perform road topology modeling based on the site information of the target test site according to the preset rules of the whole vehicle durability test specification to obtain the road topology model.

[0115] Specifically, in accordance with the requirements of the vehicle durability test specifications, the target test site information is used to perform road topology modeling. The site information of the target test site includes the test site length, slope, slope length, turning radius and speed limit, etc. In other words, a simulation model for vehicle durability testing is generated based on the above site information.

[0116] The durability test module 30 is used to import the vehicle dynamics model into the road topology model for durability condition simulation according to the preset rules of the vehicle durability test specification, and output the durability condition simulation results.

[0117] Specifically, by importing the vehicle dynamics model into the road topology model, dynamic durability simulation of the vehicle dynamics model can be performed in the road topology model. Users can then monitor the durability simulation through display devices such as computers, thereby controlling the progress of the durability simulation.

[0118] The durability simulation results include at least simulation time information and simulation vehicle information. The simulation vehicle information includes various operating parameters of the engine system and transmission system, such as speed and temperature.

[0119] In this embodiment, the established vehicle dynamics model can be stored as a file or a plugin. Similarly, the established road topology model can also be stored as a file or a plugin. Taking the plugin format as an example, in a preset simulation system, the vehicle dynamics model and the road topology model in plugin format can be imported simultaneously, and then the parameters can be set. This allows for durability simulation of the vehicle dynamics model using the road topology within the simulation system.

[0120] The information acquisition module 40 is used to acquire the input shaft information of the transmission based on the endurance condition simulation results, so as to determine the number of cycles of each gear of the transmission in each preset torque range based on the input shaft information, so as to determine the original load spectrum of the transmission.

[0121] Specifically, the acquired input shaft information of the transmission includes the speed and torque information of the input shaft. The number of cycles of each gear of the transmission in each preset torque range during the endurance simulation can be determined by the speed and torque information of the transmission input shaft. The original load spectrum of the transmission can then be determined based on the number of cycles of each gear of the transmission in each preset torque range during the endurance simulation.

[0122] The purpose of determining the original load spectrum of the transmission in this embodiment is to optimize the original load spectrum so that the durability test of the transmission can be carried out based on the optimized load spectrum in the later stage; of course, this is also the ultimate goal of the present invention.

[0123] The first calculation module 50 is used to calculate the DV value of each gear of the transmission based on the original load spectrum, so as to determine the durability target of the transmission.

[0124] The second calculation module 60 is used to iteratively calculate the actual test sample size required for the transmission and the durability target value for extended testing based on the vehicle manufacturer's reliability requirements, the test sample size, and the limit DV value of each gear of the transmission.

[0125] The third calculation module 70 is used to iteratively calculate the test load spectrum of the transmission for testing based on the durability target value, so as to conduct bench durability testing on the transmission based on the test load spectrum.

[0126] In this embodiment, the information acquisition module is specifically used for:

[0127] Based on the simulation results of the whole vehicle durability condition of the target vehicle, the input shaft information of the transmission and the gear information of the gearbox are obtained; wherein, the input shaft information includes at least the speed and torque of the input shaft;

[0128] Based on the input shaft information and gear information of the transmission, determine the number of cycles of each gear in each preset torque range;

[0129] The number of cycles is determined as the original load spectrum of the transmission; wherein the original load spectrum is the load spectrum executed when the historical transmission was tested.

[0130] In summary, compared with the prior art, the transmission durability test method shown in this embodiment has the following advantages:

[0131] By establishing a vehicle dynamics model and a road topology model, the speed-torque variation history of each gear of the transmission over time is obtained in the form of vehicle dynamics simulation under durability simulation conditions. By using the duty value (DV) method, the DV value of tooth root fracture durability damage and tooth surface pitting durability damage of each gear is quickly calculated and evaluated. According to the reliability target required by the vehicle manufacturer, the sample size required for the test and the DV value of a single test transmission are designed. The test load spectrum of each gear is obtained by iteratively solving the DV value. Then, based on the test load spectrum, the transmission is subjected to durability test to meet the durability issuance conditions of the test.

[0132] Example 3

[0133] A third embodiment of the present invention provides a computer-readable storage medium having computer instructions stored thereon, which, when executed by a processor, implement the steps of the methods described in the above embodiments.

[0134] Example 4

[0135] A fourth embodiment of the present invention provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps of the methods described in the above embodiments.

[0136] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0137] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A method for testing the durability of a transmission, characterized in that, The method includes: Based on the vehicle design parameters of the target vehicle, establish the vehicle dynamics model of the target vehicle; According to the preset rules of the vehicle durability test specification, road topology modeling is performed based on the site information of the target test site to obtain the road topology model; According to the preset rules of the vehicle durability test specification, the vehicle dynamics model is imported into the road topology model for durability condition simulation, and the durability condition simulation results are output. Based on the endurance simulation results, the input shaft information of the transmission is obtained, and the number of cycles of each gear of the transmission in each preset torque range is determined based on the input shaft information, so as to determine the original load spectrum of the transmission. Based on the original load spectrum, the DV value of each gear in the transmission is calculated to determine the durability target of the transmission. Based on the vehicle manufacturer's reliability requirements, the test sample size, and the limit DV values ​​of each gear of the transmission, the actual test sample size required for the transmission and the durability target value for the extended test are calculated iteratively. Based on the durability target value, the test load spectrum for the transmission is iteratively calculated, and the transmission is subjected to bench durability testing based on the test load spectrum. In the step of establishing the vehicle dynamics model of the target vehicle based on the vehicle design parameters, the vehicle dynamics model includes an engine model, a transmission model, a tire model, and a vehicle model. The step of obtaining the input shaft information of the transmission based on the durability simulation results, and determining the number of cycles of each gear in each preset torque range based on the input shaft information to determine the original load spectrum of the transmission, specifically includes: Based on the simulation results of the whole vehicle durability condition of the target vehicle, the input shaft information of the transmission and the gear information of the transmission are obtained; wherein, the input shaft information includes at least the speed and torque of the input shaft; Based on the input shaft information and gear information of the transmission, determine the number of cycles of each gear of the transmission in each preset torque range; The number of cycles is determined as the original load spectrum of the transmission; wherein the original load spectrum is the load spectrum executed when the historical transmission was tested.

2. The transmission durability test method according to claim 1, characterized in that, Based on the vehicle manufacturer's reliability requirements, the test sample size, and the limiting DV values ​​of each gear of the transmission, the step of iteratively calculating the actual test sample size required for the transmission and the durability target value for extended testing is as follows: The expression for calculating gear contact fatigue damage is: The expression for calculating tooth root bending fatigue damage is: In the formula, , , All of these are constants related to the specimen material. and All of these are constants related to gear design.

3. The transmission durability test method according to claim 2, characterized in that, The dimensionless value used to characterize gear contact fatigue damage and tooth root bending fatigue damage is directly proportional to the gear's input torque and rotational speed.

4. The transmission durability test method according to claim 2, characterized in that, In the formula, the =3, the =6.

5. A transmission durability testing system, characterized in that, The system, applicable to the method of any one of claims 1-4, comprises: The first modeling module is used to establish the vehicle dynamics model of the target vehicle based on the vehicle design parameters of the target vehicle. The second modeling module is used to perform road topology modeling based on the site information of the target test site according to the preset rules of the whole vehicle durability test specification to obtain the road topology model. The durability test module is used to import the vehicle dynamics model into the road topology model for durability condition simulation according to the preset rules of the vehicle durability test specification, and output the durability condition simulation results. The information acquisition module is used to acquire the input shaft information of the transmission based on the endurance condition simulation results, so as to determine the number of cycles of each gear of the transmission in each preset torque range based on the input shaft information, so as to determine the original load spectrum of the transmission. The first calculation module is used to calculate the DV value of each gear of the transmission based on the original load spectrum, so as to determine the durability target of the transmission. The second calculation module is used to iteratively calculate the actual test sample size required for the transmission and the durability target value for extended testing based on the vehicle manufacturer's reliability requirements, the test sample size, and the limit DV value of each gear of the transmission. The third calculation module is used to iteratively calculate the test load spectrum of the transmission for testing based on the durability target value, so as to conduct bench durability testing on the transmission based on the test load spectrum.

6. The transmission durability testing system according to claim 5, characterized in that, The information acquisition module is specifically used for: Based on the simulation results of the whole vehicle durability condition of the target vehicle, the input shaft information of the transmission and the gear information of the transmission are obtained; wherein, the input shaft information includes at least the speed and torque of the input shaft; Based on the input shaft information and gear information of the transmission, determine the number of cycles of each gear of the transmission in each preset torque range; The number of cycles is determined as the original load spectrum of the transmission; wherein the original load spectrum is the load spectrum executed when the historical transmission was tested.

7. A computer-readable storage medium storing computer instructions thereon, characterized in that, When executed by the processor, this instruction implements the steps of the method according to any one of claims 1-4.

8. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the steps of the method as described in any one of claims 1-4.

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