A method and apparatus for bench durability testing of an axle

Abstract

The application discloses a kind of axle's bench endurance test method and device, the method includes according to the design parameter of whole vehicle determines when axle is carried out bench endurance test, each test condition under test bench loading in each stress loading orientation Test expected stress;According to the target test condition of the axle's bench endurance test selection corresponding target test condition;According to the test expected stress in the target test condition, the axle is carried out bench endurance test, realizes in the absence of real vehicle road spectrum, obtains the input test expected stress of test bench when bench endurance test is carried out axle's bench endurance test.

Description

Technical Field

[0001] This application relates to the field of axle durability testing and technology, and in particular to a bench durability testing method and apparatus for axles. Background Technology

[0002] The axle is an important load-bearing component in the vehicle's suspension system, and its durability has a direct impact on the vehicle's driving safety. Therefore, during the development of the vehicle, it is necessary to conduct bench durability tests on the axle to verify its durability performance.

[0003] In related technologies, before conducting bench durability tests on axles, it is necessary to control a real vehicle to run on a corresponding test road, and then collect the strain conditions and corresponding drive signals of the real vehicle on the road related to the durability test. The durability test is then conducted on the test bench based on these drive signals. However, there is no real vehicle in the vehicle prototyping stage. Therefore, it is not feasible to conduct bench durability tests on axles based on relevant data from the real vehicle's road profile during the vehicle prototyping stage.

[0004] Therefore, how to conduct bench durability tests on axles without actual vehicle road data is a technical problem that urgently needs to be solved. Summary of the Invention

[0005] The main objective of this application is to provide a bench durability test method and apparatus for axles, aiming to solve the technical problem of how to conduct bench durability tests on axles when there are no actual vehicle road profiles.

[0006] In a first aspect, this application provides a bench durability test method for an axle, the method comprising the following steps:

[0007] Based on the design parameters of the whole vehicle, determine the expected test stress of the test bench under each test condition at each stress loading direction when conducting bench durability tests on the axle;

[0008] Select the corresponding target test conditions based on the bench durability test objectives of the axle;

[0009] The axle is subjected to bench durability testing based on the expected stress under the target test conditions.

[0010] In some embodiments, the stress loading orientation includes:

[0011] The X-axis of the center points of the left and right wheels on the front or rear axle and the Y-axis of the contact points of the left and right wheels;

[0012] Wherein, the X direction is along the length of the vehicle, and the Y direction is along the width of the vehicle.

[0013] In some embodiments, the test conditions include uneven road conditions, corrugated road conditions, braking-rapid acceleration conditions, turning conditions, and random conditions. Based on the vehicle's design parameters, the expected test stresses applied to the test bench at various stress loading locations under each test condition during bench durability testing of the axles are determined, including:

[0014] Based on the load Mav applied to the axle by the vehicle weight, the gravity coefficient g, and the error empirical coefficient of the test bench, the expected test stresses in the X direction and Y direction of the contact points of the left and right wheels of the front axle under uneven road conditions are determined. Based on the unsprung mass MNS of the vehicle, the gravity coefficient g, and the error empirical coefficient of the test bench, the expected test stresses in the X direction and Y direction of the contact points of the left and right wheels of the rear axle under uneven road conditions are determined.

[0015] Based on the unsprung mass MNS of the whole vehicle, the gravity coefficient g, and the error empirical coefficient of the test bench, the expected test stresses in the X direction of the center point of the left and right wheels of the front or rear axle and in the Y direction of the contact point of the left and right wheels of the front or rear axle under the washboard road condition are determined.

[0016] Based on the load Mav applied to the axle by the total vehicle weight, the height of the vehicle's center of gravity h, the design weight M when the vehicle is 3 / 4 fully loaded, the wheelbase E, the influence coefficient K×E of the wheelbase E on the force at the wheel center point, and the influence coefficient Q×E of the wheelbase E at the docking point, determine the expected test stress in the X direction of the wheel center points of the left and right wheels of the front or rear axle under braking and rapid acceleration conditions.

[0017] Based on the load Mav applied to the axle by the vehicle weight, the gravity coefficient g, the height of the vehicle's center of gravity h, and V, determine the expected test stress in the Y direction at the contact points of the left and right wheels of the front or rear axle under turning conditions.

[0018] The expected stress in the X direction of the center point of the left and right wheels of the front or rear axle under random working conditions is determined based on the unsprung mass MNS of the whole vehicle, the gravity coefficient g, and the error empirical coefficient of the test bench.

[0019] In some embodiments, selecting the corresponding target test condition based on the bench durability test objective of the axle includes:

[0020] Based on the stated bench test objectives, determine whether to conduct a bench durability test on the front axle or the rear axle of the vehicle.

[0021] If a bench endurance test is conducted on the front axle of the vehicle, the uneven road condition, the braking-rapid acceleration condition, the turning condition, and the random condition are selected as the target test conditions, and the number of cycles for each target test condition is determined according to the target mileage in the bench endurance test target.

[0022] If a bench durability test is conducted on the rear axle of the vehicle, the uneven road condition, the washboard road condition, the turning condition, and the random condition are selected as the target test conditions, and the number of cycles for each target test condition is determined according to the target mileage in the bench durability test objectives.

[0023] In some embodiments, after selecting the corresponding target test condition based on the bench durability test objective of the axle, before conducting the bench durability test on the axle based on the expected stress in the target test condition, the method further includes:

[0024] The signal functions of adjacent expected stresses in the target test conditions are connected by linear or sinusoidal interpolation.

[0025] In some embodiments, the bench durability test of the axle based on the expected stress in the target test condition includes:

[0026] A test stress signal with constant amplitude is generated based on the white noise signal;

[0027] The test stress signal is applied to the axle on the test bench, and the test response signal of the axle is obtained;

[0028] The stress transfer function of the test bench is determined based on the test stress signal and the test response signal, and the inverse function of the stress transfer function is obtained.

[0029] The test stress signal for bench durability testing of the axle is generated based on the expected test stress under the target test condition and the inverse function.

[0030] In some embodiments, generating the test stress signal for bench durability testing of the axle based on the expected test stress of the target test condition and the inverse function includes:

[0031] The expected stress of the target test condition is input into the test bench according to a preset ratio, so that the test bench applies the corresponding stress to the axle and obtains the real-time response signal of the axle.

[0032] Determine whether the error between the real-time response signal and the preset expected response signal is greater than a preset error threshold;

[0033] If not, the expected test stress of the preset ratio will be used as the test stress signal;

[0034] If so, the expected stress of the target test condition is multiplied by the inverse function to obtain the stress product result, and the stress product result is superimposed and iterated with the expected stress of the preset ratio to obtain the test stress signal.

[0035] Secondly, this application also provides a bench durability testing apparatus for axles, the apparatus comprising:

[0036] The determination module is used to determine the expected test stress of the test bench under various test conditions and stress loading directions when conducting bench durability tests on the axle, based on the design parameters of the whole vehicle.

[0037] The selection module is used to select the corresponding target test condition based on the bench durability test target of the axle;

[0038] The test module is used to perform bench durability tests on the axle according to the expected stress in the target test conditions.

[0039] In some embodiments, the stress loading orientation includes:

[0040] The X-axis of the center points of the left and right wheels on the front or rear axle and the Y-axis of the contact points of the left and right wheels;

[0041] Wherein, the X direction is along the length of the vehicle, and the Y direction is along the width of the vehicle.

[0042] In some embodiments, the test conditions include uneven road conditions, corrugated road conditions, braking-rapid acceleration conditions, turning conditions, and random conditions. The determining module is further used for:

[0043] Based on the load Mav applied to the axle by the vehicle weight, the gravity coefficient g, and the error empirical coefficient of the test bench, the expected test stresses in the X direction and Y direction of the contact points of the left and right wheels of the front axle under uneven road conditions are determined. Based on the unsprung mass MNS of the vehicle, the gravity coefficient g, and the error empirical coefficient of the test bench, the expected test stresses in the X direction and Y direction of the contact points of the left and right wheels of the rear axle under uneven road conditions are determined.

[0044] Based on the unsprung mass MNS of the whole vehicle, the gravity coefficient g, and the error empirical coefficient of the test bench, the expected test stresses in the X direction of the center point of the left and right wheels of the front or rear axle and in the Y direction of the contact point of the left and right wheels of the front or rear axle under the washboard road condition are determined.

[0045] Based on the load Mav applied to the axle by the total vehicle weight, the height of the vehicle's center of gravity h, the design weight M when the vehicle is 3 / 4 fully loaded, the wheelbase E, the influence coefficient K×E of the wheelbase E on the force at the wheel center point, and the influence coefficient Q×E of the wheelbase E at the docking point, determine the expected test stress in the X direction of the wheel center points of the left and right wheels of the front or rear axle under braking and rapid acceleration conditions.

[0046] Based on the load Mav applied to the axle by the vehicle weight, the gravity coefficient g, the height of the vehicle's center of gravity h, and V, determine the expected test stress in the Y direction at the contact points of the left and right wheels of the front or rear axle under turning conditions.

[0047] The expected stress in the X direction of the center point of the left and right wheels of the front or rear axle under random working conditions is determined based on the unsprung mass MNS of the whole vehicle, the gravity coefficient g, and the error empirical coefficient of the test bench.

[0048] This application provides a bench durability test method and apparatus for axles. It determines the expected test stress at various stress loading locations on the test bench under different test conditions during the bench durability test of the axle, based on the design parameters of the entire vehicle. It selects the corresponding target test condition according to the target of the bench durability test of the axle. The bench durability test is then conducted on the axle based on the expected test stress in the target test condition. This method enables bench durability testing of the axle to be performed without the availability of actual vehicle road data, by obtaining the expected input test stress of the test bench during the bench durability test. Attached Figure Description

[0049] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0050] Figure 1 A schematic flowchart of a bench durability test method for an axle provided in an embodiment of this application;

[0051] Figure 2 This is a schematic diagram of the test bench;

[0052] Figure 3 This is a schematic diagram showing the orientation of stress loading.

[0053] Figure 4 The expected stress values ​​applied to each stress loading direction under various operating conditions of the front axle;

[0054] Figure 5 The expected stress values ​​applied at each stress loading location under each sub-operating condition of the rear axle;

[0055] Figure 6 for Figure 4 and Figure 5 Explanation of each parameter;

[0056] Figure 7 A schematic diagram of the signal waveform for the desired stress in the experiment;

[0057] Figure 8This is a schematic block diagram of a bench durability testing apparatus for an axle, provided as an embodiment of this application.

[0058] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0059] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0060] The flowchart shown in the attached diagram is for illustrative purposes only and does not necessarily include all content and operations / steps, nor does it necessarily have to be performed in the order described. For example, some operations / steps can be broken down, combined, or partially merged, so the actual execution order may change depending on the actual situation.

[0061] This application provides a bench durability test method and apparatus for axles.

[0062] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0063] It is worth noting that, such as Figure 1 As shown, the bench durability test of an axle involves clamping the hub of the axle to be tested on a test bench and applying a certain test stress. The durability performance of the axle is then determined based on the state of the axle after the test stress is applied.

[0064] Please refer to Figure 2 , Figure 2 This is a schematic flowchart of a bench durability test method for an axle provided in an embodiment of this application.

[0065] Step S1: Determine the expected stress of the test bench under each stress loading direction when conducting bench durability tests on the axle, based on the design parameters of the whole vehicle.

[0066] Specifically, in this embodiment, the stress loading direction during the bench durability test of the axle includes the X-direction of the wheel center point K of the left and right wheels of the front or rear axle, and the Y-direction of the contact point Q of the left and right wheels. When conducting the bench durability test on the front axle of the vehicle, stress is applied to the stress loading directions of the left and right front wheels of the front axle; when conducting the bench durability test on the rear axle of the vehicle, stress is applied to the stress loading directions of the left and right rear wheels of the rear axle.

[0067] It is worth noting that the test conditions include uneven road conditions, corrugated road conditions, braking-rapid acceleration conditions, turning conditions, and random conditions. Each condition includes multiple sub-conditions. These test conditions can be set according to national vehicle durability test standards. In this implementation, the expected test stress at each stress loading position when conducting bench durability tests on the axle is calculated based on the design parameters of the whole vehicle, so that the expected test stress applied by the test bench at each stress loading position can be correlated with the stress during the actual vehicle test.

[0068] Specifically, based on the vehicle's design parameters, the expected stresses under various test conditions and applied to the test bench at different stress loading locations during bench durability testing of the axles are determined, including:

[0069] Based on the load Mav applied to the axle by the vehicle weight, the gravity coefficient g, and the error empirical coefficient of the test bench, the expected test stresses in the X direction and Y direction of the contact points of the left and right wheels of the front axle under uneven road conditions are determined. Based on the unsprung mass MNS of the vehicle, the gravity coefficient g, and the error empirical coefficient of the test bench, the expected test stresses in the X direction and Y direction of the contact points of the left and right wheels of the rear axle under uneven road conditions are determined.

[0070] Based on the unsprung mass MNS of the whole vehicle, the gravity coefficient g, and the error empirical coefficient of the test bench, the expected test stresses in the X direction of the center point of the left and right wheels of the front or rear axle and in the Y direction of the contact point of the left and right wheels of the front or rear axle under the washboard road condition are determined.

[0071] Based on the load Mav applied to the axle by the total vehicle weight, the height of the vehicle's center of gravity h, the design weight M when the vehicle is 3 / 4 fully loaded, the wheelbase E, the influence coefficient K×E of the wheelbase E on the force at the wheel center point, and the influence coefficient Q×E of the wheelbase E at the docking point, determine the expected test stress in the X direction of the wheel center points of the left and right wheels of the front or rear axle under braking and rapid acceleration conditions.

[0072] Based on the load Mav applied to the axle by the vehicle weight, the gravity coefficient g, the height of the vehicle's center of gravity h, and V, determine the expected test stress in the Y direction at the contact points of the left and right wheels of the front or rear axle under turning conditions.

[0073] The expected stress in the X direction of the center point of the left and right wheels of the front or rear axle under random working conditions is determined based on the unsprung mass MNS of the whole vehicle, the gravity coefficient g, and the error empirical coefficient of the test bench.

[0074] It is worth noting that the bench test error empirical coefficient is the difference between the durability results on the test bench and the durability results on the actual vehicle, obtained by performing durability tests on the test bench under certain working conditions and then performing the same tests on a real vehicle under the same working conditions. The bench test error empirical coefficient can be derived from the results of multiple bench durability tests. The specific methods are well known to those skilled in the art and will not be elaborated here.

[0075] Step S2: Select the corresponding target test condition according to the bench durability test target of the axle.

[0076] Specifically, the corresponding target test conditions are selected according to the bench durability test objectives of the axle, including: determining whether to conduct a bench durability test on the front axle or the rear axle of the vehicle based on the bench test objectives; if a bench durability test is conducted on the front axle, the uneven road condition, the braking-rapid acceleration condition, the turning condition, and the random condition are selected as the target test conditions, and the number of cycles for each target test condition is determined based on the target mileage in the bench durability test objectives; if a bench durability test is conducted on the rear axle, the uneven road condition, the corrugated road condition, the turning condition, and the random condition are selected as the target test conditions, and the number of cycles for each target test condition is determined based on the target mileage in the bench durability test objectives.

[0077] Exemplary, such as Figure 4 Diagram and Figure 6 As shown, MP represents the uneven road condition, TO represents the washboard road condition, FP represents the braking-rapid acceleration condition, VIR represents the turning condition, and INC represents the random condition. The uneven road condition (MP) includes 14 sub-conditions (1-14), the washboard road condition (TO) includes 2 sub-conditions (15-16), the braking-rapid acceleration condition (FP) includes 2 conditions (17-18), the turning condition (VIR) includes 2 conditions (19-20), and the random condition (INC) includes 9 conditions (21-29), totaling 29 sub-conditions across 5 conditions. X (K) represents the expected stress in the X direction at the wheel center point K, F. Y (Q) represents the expected stress in the Y direction at the grounding point Q, Z(K) represents the displacement in the Z direction at the wheel center k, left wheel represents the left wheel, and right wheel represents the right wheel. C1, C2, C3, and C4 are the empirical error coefficients of the test bench. In this example, C1 is 0.6, C2 is -0.6, C3 is 20, and C4 is -20. g is the gravity coefficient, Mav is the load applied to the axle by the total vehicle weight, MNS is the unsprung mass, h is the height of the vehicle's center of gravity, M is the design weight of the vehicle when 3 / 4 fully loaded, E is the wheelbase, K×E is the influence coefficient of wheelbase E on the force at the wheel center point K, and Q×E is the influence coefficient of the force at the connection point Q of wheelbase E.

[0078] In this embodiment, the bench durability test conditions for the front axle include uneven road condition MP, braking-acceleration condition FP, cornering condition VIR, and random condition INC, but exclude corrugated road condition TO. Therefore, sub-conditions 15-16 are not included. Figure 4 The algorithm in the test can determine the expected stress under various working conditions during the front axle bench durability test.

[0079] In this embodiment, the bench durability test conditions for the rear axle include uneven road condition MP, corrugated road condition TO, cornering condition VIR, and random condition INC, but exclude the braking-rapid acceleration condition FP. Therefore, sub-conditions 17-18 are not included. Figure 5 The algorithm in the test can determine the expected stress under various working conditions during the durability test of the rear axle test bench.

[0080] Preferably, the number of cycles for each target test condition can be determined based on the target mileage. In this embodiment, a target mileage of 33,000 kilometers is set, so the number of cycles for each target test condition of the front axle is 83 [100(5MP+20FP+6VIR)+INC], and the number of cycles for each target test condition of the rear axle is 83 [100(5MP+20TO+6VIR)+INC].

[0081] Preferably, after selecting the corresponding target test condition according to the bench durability test target of the axle, before conducting the bench durability test on the axle according to the expected test stress in the target test condition, the method further includes: connecting the signal functions of adjacent expected test stresses in the target test condition through linear or sinusoidal interpolation.

[0082] Exemplary, such as Figure 7 As shown, the calculated stress of each sub-condition has a waveform. The stress waveforms of two adjacent sub-conditions may not be continuous. Therefore, it is necessary to connect the two discontinuous points by straight line or sine interpolation to form a continuous stress waveform signal.

[0083] Step S3: Conduct a bench durability test on the axle according to the expected stress in the target test conditions.

[0084] Specifically, the step of conducting a bench durability test on the axle based on the expected test stress in the target test condition includes: generating a test stress signal with constant amplitude based on a white noise signal; applying the test stress signal to the axle on the test bench and obtaining a test response signal of the axle; determining the stress transfer function of the test bench based on the test stress signal and the test response signal, and obtaining the inverse function of the stress transfer function; and generating a test stress signal for conducting a bench durability test on the axle based on the expected test stress in the target test condition and the inverse function.

[0085] Furthermore, the step of generating a test stress signal for bench durability testing of the axle based on the expected test stress of the target test condition and the inverse function includes: inputting the expected test stress of the target test condition into the test bench according to a preset ratio, so that the test bench applies a corresponding stress to the axle, and acquiring a real-time response signal of the axle; determining whether the error between the real-time response signal and the expected response signal corresponding to the preset input stress is greater than a preset error threshold; if not, then using the expected test stress of the preset ratio as the test stress signal; if so, then multiplying the expected test stress of the target test condition by the inverse function to obtain a stress product result, superimposing and iterating the stress product result and the expected test stress of the preset ratio to obtain the test stress signal.

[0086] As an example, during bench durability testing of axles using a test bench, the stress transfer coefficient of the test bench may cause the stress applied to the axle to deviate from the input value. Therefore, in this embodiment, a computer and dedicated RPC software are used to generate "white noise," i.e., a signal with a constant amplitude at the operating frequency, and apply this signal to the axle to obtain the response at the axle sensor. The stress transfer coefficient of the test bench is determined based on the axle's response, and the inverse function is obtained by inverting the stress transfer coefficient. A Fourier transform is then performed, and the test stress signal for bench durability testing of the axle is generated based on the calculated expected stress and the inverse function.

[0087] A certain proportion of the target test condition's expected stress is input into the test bench. The error between the axle's response and the expected value after the expected test stress is calculated to see if it exceeds a preset threshold. If it is less, the certain proportion of the expected test stress input into the test bench can be used as the test stress signal for the axle's bench durability test. If it is greater, the complete expected test stress of the target test condition is multiplied by the inverse function to obtain a stress product. Then, the stress product is superimposed with the preset proportion of the expected test stress. It is then determined whether the response applied to the axle after superposition is still greater than the preset threshold. If it is still greater, the stress product is superimposed again until the error between the response and the expected value is less than the preset threshold. The superimposed stress signal is then used as the experimental stress signal.

[0088] This application provides a method and apparatus for bench durability testing of axles. The method includes determining the expected test stress at various stress loading positions on the test bench under various test conditions when conducting bench durability testing on the axle, based on the design parameters of the whole vehicle; selecting the corresponding target test condition according to the bench durability test objective of the axle; and conducting bench durability testing on the axle based on the expected test stress in the target test condition. This method enables bench durability testing of axles to be conducted without actual vehicle road data, by obtaining the input expected test stress of the test bench during bench durability testing. Furthermore, the stress loading method in this embodiment is more accurate than traditional unidirectional, constant-value bench loading.

[0089] like Figure 8 As shown in the figure, this application embodiment also provides a bench durability testing apparatus for axles, the apparatus comprising:

[0090] The determination module is used to determine the expected test stress of the test bench under various test conditions and stress loading directions when conducting bench durability tests on the axle, based on the design parameters of the whole vehicle.

[0091] The selection module is used to select the corresponding target test condition based on the bench durability test target of the axle;

[0092] The test module is used to perform bench durability tests on the axle according to the expected stress in the target test conditions.

[0093] The stress loading orientation includes:

[0094] The X-axis of the center points of the left and right wheels on the front or rear axle and the Y-axis of the contact points of the left and right wheels;

[0095] Wherein, the X direction is along the length of the vehicle, and the Y direction is along the width of the vehicle.

[0096] The test conditions include uneven road conditions, corrugated road conditions, braking-rapid acceleration conditions, turning conditions, and random conditions.

[0097] The determining module is further configured to:

[0098] Based on the load Mav applied to the axle by the vehicle weight, the gravity coefficient g, and the error empirical coefficient of the test bench, the expected test stresses in the X direction and Y direction of the contact points of the left and right wheels of the front axle under uneven road conditions are determined. Based on the unsprung mass MNS of the vehicle, the gravity coefficient g, and the error empirical coefficient of the test bench, the expected test stresses in the X direction and Y direction of the contact points of the left and right wheels of the rear axle under uneven road conditions are determined.

[0099] Based on the unsprung mass MNS of the whole vehicle, the gravity coefficient g, and the error empirical coefficient of the test bench, the expected test stresses in the X direction of the center point of the left and right wheels of the front or rear axle and in the Y direction of the contact point of the left and right wheels of the front or rear axle under the washboard road condition are determined.

[0100] Based on the load Mav applied to the axle by the total vehicle weight, the height of the vehicle's center of gravity h, the design weight M when the vehicle is 3 / 4 fully loaded, the wheelbase E, the influence coefficient K×E of the wheelbase E on the force at the wheel center point, and the influence coefficient Q×E of the wheelbase E at the docking point, determine the expected test stress in the X direction of the wheel center points of the left and right wheels of the front or rear axle under braking and rapid acceleration conditions.

[0101] Based on the load Mav applied to the axle by the vehicle weight, the gravity coefficient g, the height of the vehicle's center of gravity h, and V, determine the expected test stress in the Y direction at the contact points of the left and right wheels of the front or rear axle under turning conditions.

[0102] The expected stress in the X direction of the center point of the left and right wheels of the front or rear axle under random working conditions is determined based on the unsprung mass MNS of the whole vehicle, the gravity coefficient g, and the error empirical coefficient of the test bench.

[0103] The selection module is further used for:

[0104] Based on the stated bench test objectives, determine whether to conduct a bench durability test on the front axle or the rear axle of the vehicle.

[0105] If a bench endurance test is conducted on the front axle of the vehicle, the uneven road condition, the braking-rapid acceleration condition, the turning condition, and the random condition are selected as the target test conditions, and the number of cycles for each target test condition is determined according to the target mileage in the bench endurance test target.

[0106] If a bench durability test is conducted on the rear axle of the vehicle, the uneven road condition, the washboard road condition, the turning condition, and the random condition are selected as the target test conditions, and the number of cycles for each target test condition is determined according to the target mileage in the bench durability test objectives.

[0107] The device is also used for:

[0108] The signal functions of adjacent expected stresses in the target test conditions are connected by linear or sinusoidal interpolation.

[0109] The test module is also used for:

[0110] A test stress signal with constant amplitude is generated based on the white noise signal;

[0111] The test stress signal is applied to the axle on the test bench, and the test response signal of the axle is obtained;

[0112] The stress transfer function of the test bench is determined based on the test stress signal and the test response signal, and the inverse function of the stress transfer function is obtained.

[0113] The test stress signal for bench durability testing of the axle is generated based on the expected test stress under the target test condition and the inverse function.

[0114] The test module is also used for:

[0115] The expected stress of the target test condition is input into the test bench according to a preset ratio, so that the test bench applies the corresponding stress to the axle and obtains the real-time response signal of the axle.

[0116] Determine whether the error between the real-time response signal and the expected response signal corresponding to the preset input stress is greater than a preset error threshold.

[0117] If not, the expected test stress of the preset ratio will be used as the test stress signal;

[0118] If so, the expected stress of the target test condition is multiplied by the inverse function to obtain the stress product result. The stress product result is then superimposed and iterated with the expected stress of a preset ratio to obtain the test stress signal.

[0119] It should be noted that those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the above-described device and its modules and units can be referred to the corresponding processes in the foregoing embodiments, and will not be repeated here.

[0120] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0121] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments. The above descriptions are merely specific implementations of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A bench durability test method for an axle, characterized in that, include: Based on the design parameters of the whole vehicle, determine the expected test stress of the test bench under each test condition at each stress loading direction when conducting bench durability tests on the axle; Select the corresponding target test conditions based on the bench durability test objectives of the axle; The axle is subjected to bench durability testing based on the expected stress under the target test conditions. The stress loading orientation includes: The X-axis of the center points of the left and right wheels on the front or rear axle and the Y-axis of the contact points of the left and right wheels; Wherein, X direction is along the length of the vehicle, and Y direction is along the width of the vehicle; The test conditions include uneven road conditions, corrugated road conditions, braking-rapid acceleration conditions, turning conditions, and random conditions. Based on the vehicle's design parameters, the expected test stresses at various stress loading locations on the test bench under each test condition are determined when conducting bench durability tests on the axles. These include: Based on the load Mav applied to the axle by the vehicle weight, the gravity coefficient g, and the error empirical coefficient of the test bench, the expected test stresses in the X direction and Y direction of the contact points of the left and right wheels of the front axle under uneven road conditions are determined. Based on the unsprung mass MNS of the vehicle, the gravity coefficient g, and the error empirical coefficient of the test bench, the expected test stresses in the X direction and Y direction of the contact points of the left and right wheels of the rear axle under uneven road conditions are determined. Based on the unsprung mass MNS of the whole vehicle, the gravity coefficient g, and the error empirical coefficient of the test bench, the expected test stresses in the X direction of the center point of the left and right wheels of the front or rear axle and in the Y direction of the contact point of the left and right wheels of the front or rear axle under the washboard road condition are determined. Based on the load Mav applied to the axle by the total vehicle weight, the height of the vehicle's center of gravity h, the design weight M when the vehicle is 3 / 4 fully loaded, the wheelbase E, the influence coefficient K×E of the wheelbase E on the force at the wheel center point, and the influence coefficient Q×E of the wheelbase E at the docking point, determine the expected test stress in the X direction of the wheel center points of the left and right wheels of the front or rear axle under braking and rapid acceleration conditions. Based on the load Mav applied to the axle by the vehicle weight, the gravity coefficient g, the height of the vehicle's center of gravity h, and V, determine the expected test stress in the Y direction at the contact points of the left and right wheels of the front or rear axle under turning conditions. The expected stress in the X direction of the center point of the left and right wheels of the front or rear axle under random working conditions is determined based on the unsprung mass MNS of the whole vehicle, the gravity coefficient g, and the error empirical coefficient of the test bench.

2. The bench durability test method for axles according to claim 1, characterized in that, The step of selecting the corresponding target test condition based on the bench durability test objective of the axle includes: Based on the stated bench test objectives, determine whether to conduct a bench durability test on the front axle or the rear axle of the vehicle. If a bench endurance test is conducted on the front axle of the vehicle, the uneven road condition, the braking-rapid acceleration condition, the turning condition, and the random condition are selected as the target test conditions, and the number of cycles for each target test condition is determined according to the target mileage in the bench endurance test target. If a bench durability test is conducted on the rear axle of the vehicle, the uneven road condition, the washboard road condition, the turning condition, and the random condition are selected as the target test conditions, and the number of cycles for each target test condition is determined according to the target mileage in the bench durability test objectives.

3. The bench durability test method for axles according to claim 2, characterized in that, After selecting the corresponding target test condition based on the bench durability test objective of the axle, before conducting the bench durability test on the axle based on the expected stress in the target test condition, the process further includes: The signal functions of adjacent expected stresses in the target test conditions are connected by linear or sinusoidal interpolation.

4. The bench durability test method for axles according to claim 1, characterized in that, The bench durability test of the axle based on the expected stress in the target test condition includes: A test stress signal with constant amplitude is generated based on the white noise signal; The test stress signal is applied to the axle on the test bench, and the test response signal of the axle is obtained; The stress transfer function of the test bench is determined based on the test stress signal and the test response signal, and the inverse function of the stress transfer function is obtained. The test stress signal for bench durability testing of the axle is generated based on the expected test stress under the target test condition and the inverse function.

5. The bench durability test method for axles according to claim 4, characterized in that, The step of generating the test stress signal for bench durability testing of the axle based on the expected test stress under the target test condition and the inverse function includes: The expected stress of the target test condition is input into the test bench according to a preset ratio, so that the test bench applies the corresponding stress to the axle and obtains the real-time response signal of the axle. Determine whether the error between the real-time response signal and the expected response signal corresponding to the preset input stress is greater than a preset error threshold. If not, the expected test stress of the preset ratio will be used as the test stress signal; If so, the expected stress of the target test condition is multiplied by the inverse function to obtain the stress product result. The stress product result is then superimposed and iterated with the expected stress of a preset ratio to obtain the test stress signal.

6. A bench durability testing apparatus for axles, characterized in that, include: The determination module is used to determine the expected test stress of the test bench under various test conditions and stress loading directions when conducting bench durability tests on the axle, based on the design parameters of the whole vehicle. The selection module is used to select the corresponding target test condition based on the bench durability test target of the axle; A test module for performing bench durability tests on the axle based on the expected stress in the target test conditions; The stress loading orientation includes: The X-axis of the center points of the left and right wheels on the front or rear axle and the Y-axis of the contact points of the left and right wheels; Wherein, X direction is along the length of the vehicle, and Y direction is along the width of the vehicle; The test conditions include uneven road conditions, corrugated road conditions, braking-rapid acceleration conditions, turning conditions, and random conditions. The determination module is also used for: Based on the load Mav applied to the axle by the vehicle weight, the gravity coefficient g, and the error empirical coefficient of the test bench, the expected test stresses in the X direction and Y direction of the contact points of the left and right wheels of the front axle under uneven road conditions are determined. Based on the unsprung mass MNS of the vehicle, the gravity coefficient g, and the error empirical coefficient of the test bench, the expected test stresses in the X direction and Y direction of the contact points of the left and right wheels of the rear axle under uneven road conditions are determined. Based on the unsprung mass MNS of the whole vehicle, the gravity coefficient g, and the error empirical coefficient of the test bench, the expected test stresses in the X direction of the center point of the left and right wheels of the front or rear axle and in the Y direction of the contact point of the left and right wheels of the front or rear axle under the washboard road condition are determined. Based on the load Mav applied to the axle by the total vehicle weight, the height of the vehicle's center of gravity h, the design weight M when the vehicle is 3 / 4 fully loaded, the wheelbase E, the influence coefficient K×E of the wheelbase E on the force at the wheel center point, and the influence coefficient Q×E of the wheelbase E at the docking point, determine the expected test stress in the X direction of the wheel center points of the left and right wheels of the front or rear axle under braking and rapid acceleration conditions. Based on the load Mav applied to the axle by the vehicle weight, the gravity coefficient g, the height of the vehicle's center of gravity h, and V, determine the expected test stress in the Y direction at the contact points of the left and right wheels of the front or rear axle under turning conditions. The expected stress in the X direction of the center point of the left and right wheels of the front or rear axle under random working conditions is determined based on the unsprung mass MNS of the whole vehicle, the gravity coefficient g, and the error empirical coefficient of the test bench.

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