A method and system for determining spring life

Abstract

The application provides a method and system for determining the service life of a spring, which determines the stiffness coefficient of the spring by the spring deformation and the load obtained before and after the fatigue test of the spring, calculates the release time corresponding to different fatigue test times according to the stiffness coefficient and the pre-determined initial parameters of the spring, finally determines the functional expression of the release time according to the corresponding relationship between the fatigue test times and the release time, and determines the fatigue test times of the spring to be tested, that is, the service life, according to the functional expression and the set release time threshold. The method and system consider the actual working environment and load condition of the spring, calculate the influence of the spring relaxation on the release time, and thus predict the service life of the spring. The method is convenient to operate, simple to calculate, and high in reliability, and improves the efficiency and accuracy of determining the service life of the spring.

Description

Technical Field

[0001] This invention relates to the field of spring life prediction technology, and more specifically, to a method and system for determining spring life. Background Technology

[0002] The failure of helical springs during use mainly takes two forms: fatigue fracture and stress relaxation. Stress relaxation is essentially the process by which the elastic strain of a spring continuously transforms into plastic strain under stress. The stress relaxation behavior of a spring reduces the energy stored within a certain length, leading not only to a decrease in spring force but also affecting its dynamic performance during release, thus prolonging the time required for the spring to recover from a compressed state to a relaxed state (i.e., the release time). Some precision instruments have strict requirements on the release time of springs; when the release time exceeds a certain threshold, it can cause timing characteristic failures in the system. For springs used in these applications, considering their operating environment and load conditions, analyzing the impact of stress relaxation on their release time is crucial.

[0003] Current methods for predicting the stress relaxation life of helical springs primarily consider the impact of decreased spring load-bearing capacity on spring life. Typically, the spring is compressed to a certain height, and then the load change is measured at regular intervals to obtain the stress variation pattern, plotting a relaxation rate curve to predict the spring's lifespan. This method is simple to implement and easy to operate, reflecting the change in spring relaxation rate over time under static load. However, some springs require frequent switching during service, and the failure criterion is not only determined by load-bearing capacity but also closely related to the release time. Traditional stress relaxation life prediction methods cannot simulate the frequent switching conditions of springs, nor can they reflect changes in spring release time; therefore, they cannot accurately predict the spring's lifespan. Summary of the Invention

[0004] To address the technical problem that existing spring life prediction methods do not simulate the frequent switching conditions of springs and cannot reflect changes in spring release time, thus leading to deviations in the prediction of spring life, this invention provides a method and system for determining spring life.

[0005] According to one aspect of the present invention, the present invention provides a method for determining the service life of a spring, the method comprising:

[0006] The initial load of the spring to be tested is obtained, and the remaining load of the spring under different fatigue test cycles is obtained after conducting fatigue tests on the spring according to the predetermined spring deformation based on the actual working conditions.

[0007] The initial stiffness coefficient is calculated based on the initial load and the predetermined spring deformation, and the stiffness coefficient of the spring under test at the corresponding fatigue test number is calculated based on the remaining load and the predetermined spring deformation.

[0008] The initial release time and test release time of the spring under test are calculated based on the predetermined initial release displacement value, release termination displacement value, resistance coefficient, mass of the load connected to the spring under test, initial stiffness coefficient, and stiffness coefficient of the spring under test in the corresponding fatigue test number.

[0009] The service life of the spring under test is determined based on the number of fatigue tests, the initial release time, the test release time, and the set release time threshold.

[0010] Furthermore, before obtaining the initial load on the spring to be tested, the initial parameters of the spring are obtained, wherein:

[0011] The free height of the spring to be tested is determined by using the bottom end of the spring as a reference point;

[0012] Determine the mass of the load connected to the spring under test, and determine the first height of the spring under test when compressed after being connected to the load and the second height when released, with the bottom end of the spring under test as the reference point;

[0013] The spring deformation of the spring to be tested is calculated based on the free height and the second height.

[0014] Using the top of the spring to be tested as a reference point, calculate the initial release displacement value of the spring to be tested based on the free height and the first height, and calculate the release termination displacement value of the spring to be tested based on the free height and the second height.

[0015] Determine the resistance coefficient of the spring to be tested when it is released.

[0016] Furthermore, the initial stiffness coefficient is calculated based on the initial load and the predetermined spring deformation, and the stiffness coefficient of the spring under test at the corresponding fatigue test number is calculated based on the remaining load and the predetermined spring deformation. The calculation formula is as follows:

[0017]

[0018]

[0019] In the formula, k0 is the initial spring constant, F0 is the initial load, Δx is the spring deformation of the spring under test, and k i F is the stiffness coefficient after i fatigue tests. i Let i be the remaining load after i fatigue tests, where i is a non-zero natural number.

[0020] Furthermore, based on the predetermined initial release displacement value, final release displacement value, resistance coefficient, and mass of the load connected to the spring under test, as well as the initial stiffness coefficient and the stiffness coefficient of the spring under test in the corresponding fatigue test number, the initial release time and test release time of the spring under test are calculated respectively. The calculation formula is as follows:

[0021]

[0022]

[0023]

[0024]

[0025] In the formula, x0 and x are the initial and final release displacements of the spring under test, respectively; c is the resistance coefficient of the spring under test; M is the mass of the load connected to the spring under test; t0 is the initial release time; and t i This represents the test release time corresponding to the number of fatigue test cycles i.

[0026] According to another aspect of the present invention, the present invention provides a system for determining the service life of a spring, the system comprising:

[0027] The data acquisition unit is used to acquire the initial load of the spring under test, and to acquire the remaining load of the spring under test after fatigue tests are conducted on the spring according to the predetermined spring deformation based on the actual working conditions, after different fatigue test cycles.

[0028] The stiffness coefficient unit is used to calculate the initial stiffness coefficient based on the initial load and the predetermined spring deformation, and to calculate the stiffness coefficient of the spring under test at the corresponding fatigue test number based on the remaining load and the predetermined spring deformation.

[0029] The release time unit is used to calculate the initial release time and test release time of the spring under test based on the predetermined initial release displacement value, release termination displacement value, resistance coefficient, and mass of the load connected to the spring under test, as well as the initial stiffness coefficient and the stiffness coefficient of the spring under test in the corresponding fatigue test number.

[0030] The calculation results unit is used to determine the service life of the spring under test based on the number of fatigue tests, the initial release time, the test release time, and the set release time threshold.

[0031] Furthermore, the system also includes an initial parameter unit for obtaining the initial parameters of the spring, wherein:

[0032] The free height of the spring to be tested is determined by using the bottom end of the spring as a reference point;

[0033] Determine the mass of the load connected to the spring under test, and determine the first height of the spring under test when compressed after being connected to the load and the second height when released, with the bottom end of the spring under test as the reference point;

[0034] The spring deformation of the spring to be tested is calculated based on the free height and the second height.

[0035] Using the top of the spring under test as a reference point, calculate the initial release displacement value of the spring under test based on its free height and first height; calculate the final release displacement value of the spring under test based on its free height and second height; and

[0036] Determine the resistance coefficient of the spring to be tested when it is released.

[0037] Furthermore, the stiffness coefficient unit calculates the initial stiffness coefficient based on the initial load and the predetermined spring deformation, and calculates the stiffness coefficient of the spring under test at the corresponding fatigue test number based on the remaining load and the predetermined spring deformation. The calculation formula is as follows:

[0038]

[0039]

[0040] In the formula, k0 is the initial spring constant, F0 is the initial load, Δx is the spring deformation of the spring under test, and k i F is the stiffness coefficient after i fatigue tests. i Let i be the remaining load after i fatigue tests, where i is a non-zero natural number.

[0041] Furthermore, the release time unit calculates the initial release time and test release time of the spring under test based on the predetermined initial release displacement value, release termination displacement value, resistance coefficient, mass of the load connected to the spring under test, and the initial stiffness coefficient and the stiffness coefficient of the spring under test in the corresponding fatigue test number, respectively. The calculation formula is as follows:

[0042]

[0043]

[0044]

[0045]

[0046] In the formula, x0 and x are the initial and final release displacements of the spring under test, respectively; c is the resistance coefficient of the spring under test; M is the mass of the load connected to the spring under test; t0 is the initial release time; and t i This represents the test release time corresponding to the number of fatigue test cycles i.

[0047] Furthermore, the calculation result unit determines the service life of the spring under test based on the number of fatigue tests, the initial release time, the test release time, and the set release time threshold, including:

[0048] Let the fatigue test count corresponding to the initial release time be 0. Based on the correspondence between the fatigue test count of the spring under test and the initial release time, determine the functional relationship between the fatigue test count and the release time, where the expression for the release time is:

[0049] t j =f(j)

[0050] In the formula, j represents the number of fatigue tests on the spring to be tested, which is a natural number; f(j) represents the release time as a function of the number of fatigue tests j; and t j This represents the release time when the number of fatigue tests is j;

[0051] The release time threshold t of the spring under test is determined based on the aforementioned release time expression. max Number of fatigue tests j max j max This refers to the lifespan of the spring being tested.

[0052] The method and system for determining spring service life according to this invention determine the spring stiffness coefficient by measuring the spring deformation and the load acquired before and after fatigue testing. Based on the stiffness coefficient and predetermined initial spring parameters, the release time corresponding to different fatigue test cycles is calculated. Finally, a functional expression for the release time is determined based on the correspondence between the number of fatigue tests and the release time. Then, the number of fatigue tests, i.e., the service life, is determined based on the functional expression and a set release time threshold. This method and system, considering the actual working environment and load conditions of the spring, calculates the impact of spring relaxation on the release time, thereby predicting the spring's service life. The method is convenient to operate, simple to calculate, and highly reliable, improving the efficiency and accuracy of determining spring service life. Attached Figure Description

[0053] Exemplary embodiments of the present invention can be more fully understood by referring to the following figures:

[0054] Figure 1A flowchart illustrating a method for determining the service life of a spring according to a preferred embodiment of the present invention;

[0055] Figure 2 This is a simplified working model of a spring according to a preferred embodiment of the present invention;

[0056] Figure 3 This is a schematic diagram of the coordinates of the number of spring fatigue tests and the release time according to a preferred embodiment of the present invention;

[0057] Figure 4 This is a schematic diagram of a system for determining the service life of a spring according to a preferred embodiment of the present invention. Detailed Implementation

[0058] Exemplary embodiments of the invention will now be described with reference to the accompanying drawings. However, the invention may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to fully and completely disclose the invention and to fully convey its scope to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the drawings is not intended to limit the invention. In the drawings, the same units / elements are referred to by the same reference numerals.

[0059] Unless otherwise stated, the terms used herein (including technical terms) have their common meaning as understood by one of ordinary skill in the art. Furthermore, it is understood that terms defined in commonly used dictionaries should be understood to have a meaning consistent with the context of their relevant field, and not to be interpreted as having an idealized or overly formal meaning.

[0060] Exemplary methods

[0061] Figure 1 This is a flowchart illustrating a method for determining the service life of a spring according to a preferred embodiment of the present invention. Figure 1 As shown, the method for determining the service life of a spring according to this preferred embodiment begins from step 101.

[0062] In step 101, the initial load of the spring to be tested is obtained, and the remaining load of the spring to be tested under different fatigue test cycles is obtained after conducting fatigue tests on the spring according to the predetermined spring deformation based on the actual working conditions.

[0063] Preferably, obtaining the initial load of the spring to be tested includes obtaining the initial parameters of the spring, wherein:

[0064] The free height of the spring to be tested is determined by using the bottom end of the spring as a reference point;

[0065] Determine the mass of the load connected to the spring under test, and determine the first height of the spring under test when compressed after being connected to the load and the second height when released, with the bottom end of the spring under test as the reference point;

[0066] The spring deformation of the spring to be tested is calculated based on the free height and the second height.

[0067] Using the top of the spring to be tested as a reference point, calculate the initial release displacement value of the spring to be tested based on the free height and the first height, and calculate the release termination displacement value of the spring to be tested based on the free height and the second height.

[0068] Determine the resistance coefficient of the spring to be tested when it is released.

[0069] The principle by which this preferred embodiment predicts the service life of the spring is as follows. Figure 2 This is a simplified working model of a spring according to a preferred embodiment of the present invention. For example... Figure 2 As shown, neglecting the mass of the spring, assume the spring is connected to a spherical load of mass M and radius R, and the viscosity of the working medium is η. The spring is required to rapidly return from its remaining height H1 to its remaining height H2 when released; the time consumed in this process is the release time t.

[0070] Force analysis of the load reveals that after the spring is released, the load experiences both the spring's thrust and the medium's resistance. The resultant force can be expressed by the acceleration equation as follows:

[0071] -kx-cv=Ma

[0072] In the formula, -kx is the thrust of the spring on the load, k is the spring constant, x is the displacement of the spring relative to the load when uncompressed, and the extension direction of the spring when unloaded is taken as the positive direction, so x is negative for the spring under compression; -cv is the resistance force on the spring, c is the resistance coefficient, which depends on the volume of the load and the viscosity of the medium. When it is spherical, c can be approximated as -6πηR, and v is the velocity of the load. Then, according to the acceleration equation, the differential equation can be obtained as follows:

[0073]

[0074] Solving the above differential equations, when the environmental damping is small, the spring will still oscillate after being released, and its equation of motion can be obtained as follows:

[0075]

[0076]

[0077]

[0078]

[0079]

[0080]

[0081] In the formula, x0 is the displacement of the spring when it is compressed relative to the load, and it is a negative value. The time taken for the spring to be released to the specified position, which is the release time t, can be obtained by using the above equation of motion.

[0082] As can be seen from the above equation of motion, the service life of a spring can be determined once the spring constant, the mass of the load connected to the spring, the displacement of the load when it is compressed and the displacement after it is released, the deformation of the spring, and the resistance coefficient are known.

[0083] In this preferred embodiment, a suitable fixture is selected as the spring to be tested based on the actual working conditions and spring dimensions. Taking the main spring in an on-load tap changer as an example, its lifespan is predicted considering the release time. On-load tap changers have timing requirements, therefore the release time of the main spring needs to be strictly controlled. Before the fatigue test, the free height of the spring is determined to be 197mm, and the spring is connected to a 75kg spherical load with a radius of 120mm. The viscosity of the spring at room temperature is 15.3mm. 2 Operating in transformer oil at a speed of / s, when the switch is accumulating energy, the remaining spring height H1 is 130mm, equivalent to the first height of 130mm. When the switch is switched, the spring needs to quickly release energy and return to the remaining height H2 of 185mm, equivalent to the second height of 185mm. Based on the free height and the first height, the initial release displacement value x0 = 130 - 197 = -67mm, the release termination displacement value x = 185 - 197 = -12mm, and the spring deformation Δx = 197 - 185 = 12mm. The resistance coefficient c depends on the volume of the load and the viscosity of the medium. When it is spherical, the resistance coefficient c is approximately taken as -6πηR, and the calculated value is c = 34.59.

[0084] After determining the initial parameters of the spring to be tested, an electronic tensile testing machine was used to measure the initial load of the spring before the fatigue test. Fatigue tests were conducted with different numbers of cycles by adjusting the amplitude and frequency of the spring fatigue testing machine. In this preferred embodiment, the spring was installed in a KLD-E(1421) electronic tensile testing machine, and the initial load F0 when the remaining height of the spring was 185mm was measured to be 149.45N. A KPD-104(1221) was used to conduct fatigue tests on the spring, switching between two states with a remaining height of 130mm and 185mm to simulate the actual working state of the spring. Every 500,000 fatigue cycles, the spring was removed, and its load F at a remaining height of 185mm was measured again using the KLD-E(1421) electronic tensile testing machine. i A total of 10 million fatigue tests were conducted.

[0085] In step 102, the initial stiffness coefficient is calculated based on the initial load and the predetermined spring deformation, and the stiffness coefficient of the spring to be tested at the corresponding fatigue test number is calculated based on the remaining load and the predetermined spring deformation.

[0086] Preferably, the initial stiffness coefficient is calculated based on the initial load and the predetermined spring deformation, and the stiffness coefficient of the spring under test at the corresponding fatigue test number is calculated based on the remaining load and the predetermined spring deformation. The calculation formula is as follows:

[0087]

[0088]

[0089] In the formula, k0 is the initial spring constant, F0 is the initial load, Δx is the spring deformation of the spring under test, and k i F is the stiffness coefficient after i fatigue tests. i Let i be the remaining load after i fatigue tests, where i is a non-zero natural number.

[0090] In a preferred embodiment, the spring deformation Δx is 0.012m, the initial load F0 is 149.45N, and the initial spring constant k0 is 12454.17N / m according to the formula. This is based on the residual load F measured after every 500,000 tests. i The stiffness coefficient k can be calculated using the stiffness coefficient formula. i .

[0091] In step 103, the initial release time and test release time of the spring under test are calculated based on the predetermined initial release displacement value, release termination displacement value, resistance coefficient, mass of the load connected to the spring under test, initial stiffness coefficient, and stiffness coefficient of the spring under test in the corresponding fatigue test number.

[0092] Preferably, the initial release time and test release time of the spring under test are calculated based on the predetermined initial release displacement value, release termination displacement value, resistance coefficient, and mass of the load connected to the spring under test, as well as the initial stiffness coefficient and the stiffness coefficient of the spring under test in the corresponding fatigue test number. The calculation formula is as follows:

[0093]

[0094]

[0095]

[0096]

[0097] In the formula, x0 and x are the initial and final release displacements of the spring under test, respectively; c is the resistance coefficient of the spring under test; M is the mass of the load connected to the spring under test; t0 is the initial release time; and t i This represents the test release time corresponding to the number of fatigue test cycles i.

[0098] In this preferred embodiment, the initial release displacement x0 = -67 mm, the release termination displacement x = -12 mm, c = 34.59, M = 75, and k0 = 12454.17 N / m. Substituting these parameter values ​​into the formula for calculating the initial release time, the calculation is performed using analysis software MATLAB or Excel, where t0 equals 108.9 ms. Using the same method, the stiffness coefficient k is calculated... i In this case, the test release time corresponding to the number of fatigue tests can also be calculated.

[0099] In step 104, the service life of the spring under test is determined based on the number of fatigue tests, the initial release time, the test release time, and the set release time threshold.

[0100] Preferably, the service life of the spring under test is determined based on the number of fatigue tests, the initial release time, the test release time, and a set release time threshold, including:

[0101] Let the fatigue test count corresponding to the initial release time be 0. Based on the correspondence between the fatigue test count of the spring under test and the initial release time, determine the functional relationship between the fatigue test count and the release time, where the expression for the release time is:

[0102] t j =f(j)

[0103] In the formula, j represents the number of fatigue tests on the spring to be tested, which is a natural number; f(j) represents the release time as a function of the number of fatigue tests j; and t j This represents the release time when the number of fatigue tests is j;

[0104] The release time threshold t of the spring under test is determined based on the aforementioned release time expression. max Number of fatigue tests j max j max This refers to the lifespan of the spring being tested.

[0105] Figure 3 This is a schematic diagram showing the coordinates of the number of spring fatigue tests and the release time according to a preferred embodiment of the present invention. Figure 3 As shown in the diagram, when the number of fatigue tests on the spring is 0, the release time is 108.9 ms. As the number of fatigue tests increases, the release time gradually increases, reaching 111.1 ms when the number of fatigue tests reaches 10 million. Based on the above coordinate diagram, the functional relationship between the release time and the number of fatigue tests can be determined. Therefore, after determining the release time threshold, the corresponding number of fatigue tests can be easily calculated, thus accurately predicting the spring's service life.

[0106] Exemplary System

[0107] Figure 4 This is a schematic diagram of a system for determining the service life of a spring according to a preferred embodiment of the present invention. Figure 4 As shown, the system for determining the service life of a spring according to this preferred embodiment includes:

[0108] The data acquisition unit 401 is used to acquire the initial load of the spring to be tested, and to acquire the remaining load of the spring to be tested under different fatigue test cycles after conducting fatigue tests on the spring according to a predetermined spring deformation based on actual working conditions.

[0109] The stiffness coefficient unit 402 is used to calculate the initial stiffness coefficient based on the initial load and the predetermined spring deformation, and to calculate the stiffness coefficient of the spring under test at the corresponding fatigue test number based on the remaining load and the predetermined spring deformation.

[0110] Release time unit 403 is used to calculate the initial release time and test release time of the spring under test based on the predetermined initial release displacement value, release termination displacement value, resistance coefficient and mass of the load connected to the spring under test, as well as the initial stiffness coefficient and the stiffness coefficient of the spring under test in the corresponding fatigue test number.

[0111] The calculation result unit 404 is used to determine the service life of the spring under test based on the number of fatigue tests, the initial release time, the test release time, and the set release time threshold.

[0112] Preferably, the system further includes an initial parameter unit for obtaining the initial parameters of the spring, wherein:

[0113] The free height of the spring to be tested is determined by using the bottom end of the spring as a reference point;

[0114] Determine the mass of the load connected to the spring under test, and determine the first height of the spring under test when compressed after being connected to the load and the second height when released, with the bottom end of the spring under test as the reference point;

[0115] The spring deformation of the spring to be tested is calculated based on the free height and the second height.

[0116] Using the top of the spring under test as a reference point, calculate the initial release displacement value of the spring under test based on its free height and first height; calculate the final release displacement value of the spring under test based on its free height and second height; and

[0117] Determine the resistance coefficient of the spring to be tested when it is released.

[0118] Preferably, the stiffness coefficient unit 402 calculates the initial stiffness coefficient based on the initial load and the predetermined spring deformation, and calculates the stiffness coefficient of the spring under test at the corresponding fatigue test number based on the remaining load and the predetermined spring deformation. The calculation formula is as follows:

[0119]

[0120]

[0121] In the formula, k0 is the initial spring constant, F0 is the initial load, Δx is the spring deformation of the spring under test, and k i F is the stiffness coefficient after i fatigue tests. i Let i be the remaining load after i fatigue tests, where i is a non-zero natural number.

[0122] Preferably, the release time unit 403 calculates the initial release time and test release time of the spring under test based on the predetermined initial release displacement value, release termination displacement value, resistance coefficient, and mass of the load connected to the spring under test, as well as the initial stiffness coefficient and the stiffness coefficient of the spring under test in the corresponding fatigue test number. The calculation formula is as follows:

[0123]

[0124]

[0125]

[0126]

[0127] In the formula, x0 and x are the initial and final release displacements of the spring under test, respectively; c is the resistance coefficient of the spring under test; M is the mass of the load connected to the spring under test; t0 is the initial release time; and t i This represents the test release time corresponding to the number of fatigue test cycles i.

[0128] Preferably, the calculation result unit 404 determines the service life of the spring under test based on the number of fatigue tests, the initial release time, the test release time, and the set release time threshold, including:

[0129] Let the fatigue test count corresponding to the initial release time be 0. Based on the correspondence between the fatigue test count of the spring under test and the initial release time, determine the functional relationship between the fatigue test count and the release time, where the expression for the release time is:

[0130] t j =f(j)

[0131] In the formula, j represents the number of fatigue tests on the spring to be tested, which is a natural number; f(j) represents the release time as a function of the number of fatigue tests j; and t j This represents the release time when the number of fatigue tests is j;

[0132] The release time threshold t of the spring under test is determined based on the aforementioned release time expression. max Number of fatigue tests j max j max This refers to the lifespan of the spring being tested.

[0133] The system for determining the service life of a spring described in this preferred embodiment determines the spring stiffness coefficient by the spring deformation and the load acquired before and after the fatigue test. Based on the stiffness coefficient and predetermined initial spring parameters, it calculates the release time corresponding to different fatigue test cycles. Finally, it determines the functional expression of the release time based on the correspondence between the number of fatigue tests and the release time, and then determines the number of fatigue tests, i.e., the service life, of the spring under test based on the functional expression and the set release time threshold. The steps are the same as those used in the method for determining the service life of a spring described in this invention, and the technical effects achieved are also the same, so they will not be repeated here.

[0134] The invention has been described with reference to a few embodiments. However, as will be known to those skilled in the art, and as defined in the appended claims, other embodiments besides those disclosed above fall equivalently within the scope of the invention.

[0135] Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the art, unless otherwise expressly defined herein. All references to “a / the / the [device, component, etc.]” ​​are openly interpreted as at least one instance of said device, component, etc., unless otherwise expressly stated. The steps of any method disclosed herein need not be performed in the exact order disclosed unless explicitly stated otherwise.

[0136] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0137] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0138] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0139] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0140] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for determining the service life of a spring, characterized in that, The method includes: The initial load of the spring to be tested is obtained, and the remaining load of the spring under different fatigue test cycles is obtained after conducting fatigue tests on the spring according to the predetermined spring deformation based on the actual working conditions. The initial stiffness coefficient is calculated based on the initial load and the predetermined spring deformation, and the stiffness coefficient of the spring under test at the corresponding fatigue test number is calculated based on the remaining load and the predetermined spring deformation. The calculation formula is as follows: In the formula, The initial stiffness coefficient, For the initial load, The spring deformation is the amount of the spring to be tested. In order to conduct Stiffness coefficient after fatigue test In order to conduct Residual load after fatigue test It is a non-zero natural number; Based on the predetermined initial release displacement value, final release displacement value, resistance coefficient, and mass of the load connected to the spring under test, as well as the initial stiffness coefficient and the stiffness coefficient of the spring under test in the corresponding fatigue test number, the initial release time and test release time of the spring under test are calculated respectively. The calculation formula is as follows: In the formula, and These are the initial release displacement and the final release displacement of the spring under test, respectively. The resistance coefficient of the spring to be tested when it is released. The mass of the load connected to the spring to be tested. For the initial release time, Indicates the number of fatigue tests. The corresponding test release time; The service life of the spring under test is determined based on the number of fatigue tests, the initial release time, the test release time, and the set release time threshold, including: Let the fatigue test count corresponding to the initial release time be 0. Based on the correspondence between the fatigue test count of the spring under test and the initial release time, determine the functional relationship between the fatigue test count and the release time, where the expression for the release time is: In the formula, This indicates the number of fatigue tests conducted on the spring under test, and is a natural number. Indicates the number of fatigue tests. The function of release time. Indicates the number of fatigue tests. Release time; The release time threshold of the spring under test is determined based on the aforementioned release time expression. Number of fatigue tests , This refers to the lifespan of the spring being tested.

2. The method according to claim 1, characterized in that, Before obtaining the initial load on the spring to be tested, it is necessary to obtain the initial parameters of the spring, including: The free height of the spring to be tested is determined by using the bottom end of the spring as a reference point; Determine the mass of the load connected to the spring under test, and determine the first height of the spring under test when compressed after being connected to the load and the second height when released, with the bottom end of the spring under test as the reference point; The spring deformation of the spring to be tested is calculated based on the free height and the second height. Using the top of the spring to be tested as a reference point, calculate the initial release displacement value of the spring to be tested based on the free height and the first height, and calculate the release termination displacement value of the spring to be tested based on the free height and the second height. Determine the resistance coefficient of the spring to be tested when it is released.

3. A system for determining the service life of a spring, characterized in that, The system includes: The data acquisition unit is used to acquire the initial load of the spring under test, and to acquire the remaining load of the spring under test after fatigue tests are conducted on the spring according to the predetermined spring deformation based on the actual working conditions, after different fatigue test cycles. The stiffness coefficient unit is used to calculate the initial stiffness coefficient based on the initial load and the predetermined spring deformation, and to calculate the stiffness coefficient of the spring under test at the corresponding fatigue test number based on the remaining load and the predetermined spring deformation. The calculation formula is as follows: In the formula, The initial stiffness coefficient, For the initial load, The spring deformation is the amount of the spring to be tested. In order to conduct Stiffness coefficient after fatigue test In order to conduct Residual load after fatigue test It is a non-zero natural number; The release time unit is used to calculate the initial release time and test release time of the spring under test based on the predetermined initial release displacement value, release termination displacement value, resistance coefficient, and mass of the load connected to the spring under test, as well as the initial stiffness coefficient and the stiffness coefficient of the spring under test in the corresponding fatigue test number. The calculation formula is as follows: In the formula, and These are the initial release displacement and the final release displacement of the spring under test, respectively. The resistance coefficient of the spring to be tested when it is released. The mass of the load connected to the spring to be tested. For the initial release time, Indicates the number of fatigue tests. The corresponding test release time; The calculation result unit is used to determine the service life of the spring under test based on the number of fatigue tests, initial release time, test release time, and a set release time threshold, including: Let the fatigue test count corresponding to the initial release time be 0. Based on the correspondence between the fatigue test count of the spring under test and the initial release time, determine the functional relationship between the fatigue test count and the release time, where the expression for the release time is: In the formula, This indicates the number of fatigue tests conducted on the spring under test, and is a natural number. Indicates the number of fatigue tests. The function of release time. Indicates the number of fatigue tests. Release time; The release time threshold of the spring under test is determined based on the aforementioned release time expression. Number of fatigue tests , This refers to the lifespan of the spring being tested.

4. The system according to claim 3, characterized in that, The system also includes an initial parameter unit for obtaining the initial parameters of the spring, wherein: The free height of the spring to be tested is determined by using the bottom end of the spring as a reference point; Determine the mass of the load connected to the spring under test, and determine the first height of the spring under test when compressed after being connected to the load and the second height when released, with the bottom end of the spring under test as the reference point; The spring deformation of the spring to be tested is calculated based on the free height and the second height. Using the top of the spring under test as a reference point, calculate the initial release displacement value of the spring under test based on its free height and first height; calculate the final release displacement value of the spring under test based on its free height and second height; and Determine the resistance coefficient of the spring to be tested when it is released.

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