Bolt slippage safety coefficient testing method, testing tool and testing system

Abstract

The invention provides a bolt slippage safety coefficient test method, a test tool and a test system, and relates to the technical field of vehicles. The method comprises the following steps: acquiring an assembly geometric model of a test tool and a test part, and establishing a vibration simulation model; determining candidate bolts of candidate models according to the vibration simulation model and the bolt slippage safety coefficient of the test part; under the condition that the test part is assembled on the test tool according to the candidate bolt of the candidate model and the assembly geometric model, the test tool is controlled to vibrate according to a set frequency interval, and the connection states between the candidate bolt and the test part at different moments are obtained; and according to the connection state between the candidate bolt and the test part at different moments, updating the bolt slippage safety coefficient. According to the method, the bolt slippage safety coefficient of the part is calibrated and updated, the fixing bolt of a proper model can be accurately configured for the part, and the part is prevented from loosening.

Description

Technical Field

[0001] The invention belongs to the technical field of vehicles, and in particular relates to a bolt slip safety factor testing method, a testing tool and a testing system. Background Art

[0002] The bolt slip safety factor is an important parameter for evaluating the performance of bolt connections. There are various parts in a vehicle that need to be fastened with bolts. Bolts may become loose during long-term driving. Therefore, it is necessary to accurately evaluate the bolt slip safety factor. Based on the accurate bolt slip safety factor, the appropriate type of bolts can be selected to fasten parts and prevent them from becoming loose.

[0003] At present, the bolt model specifications of various parts in the vehicle are generally empirical values. Subjective empirical values ​​are inaccurate, which may easily lead to the possibility of bolts loosening, causing a series of potential risks. Summary of the invention

[0004] The embodiments of the present invention provide a bolt slip safety factor testing method, a testing tool and a testing system, which can calibrate the bolt slip safety factor of a part and more accurately configure the part with a suitable type of fixing bolt to prevent the part from loosening.

[0005] In a first aspect, an embodiment of the present invention provides a method for testing a bolt slip safety factor, comprising:

[0006] Obtain the assembly geometry model of the test fixture and test parts, and establish a vibration simulation model;

[0007] Determining candidate bolts of candidate models according to the vibration simulation model and the bolt slip safety factor of the test part;

[0008] When the test part is assembled on the test fixture according to the candidate bolt of the candidate model and the assembly geometric model, the test fixture is controlled to vibrate according to a set frequency range to obtain the connection state between the candidate bolt and the test part at different times;

[0009] The bolt slip safety factor of the test part is updated according to the connection status between the candidate bolt and the test part at different times.

[0010] In a second aspect, an embodiment of the present invention provides a test fixture, which is provided with at least one slide groove extending in different extension directions, and the slide groove is provided with a bracket that can slide in the extension direction, and the bracket is used to bolt and fix different types of test parts.

[0011] In a third aspect, an embodiment of the present invention provides a test system, comprising a sensor, a vibration table, a test device, an electronic device and the above-mentioned test fixture, wherein the test fixture is arranged on the vibration table, the test part is arranged on the test fixture by bolts, the sensor is arranged on the test part, and the test device is connected to the sensor and the electronic device respectively;

[0012] The vibration table is used to drive the test fixture and the test parts arranged on the test fixture to vibrate according to a set frequency;

[0013] The sensor is used to collect vibration data of the test part and transmit it to the electronic device;

[0014] The electronic device is used to determine whether the test part resonates based on the vibration data.

[0015] The bolt slip safety factor testing method, testing tooling and testing system provided in the embodiments of the present application can realize the precise bolt slip safety factor of the test parts, improve the accuracy of the bolt slip safety factor, and more accurately configure the parts with suitable types of fixing bolts to prevent the parts from loosening, thereby avoiding the problems of over-design and under-design of bolt models when selecting bolt fixing parts based on subjective experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solution of the embodiment of the present invention, the following is a brief introduction to the drawings required for use in the embodiment of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1A A schematic diagram of the structure of the test system provided in the embodiment of the present application;

[0018] Figure 1B A schematic diagram of the structure of the test tool provided in the embodiment of the present application at different viewing angles;

[0019] Figure 2 A schematic diagram of a flow chart of a bolt slip safety factor testing method provided in an embodiment of the present application;

[0020] Figure 3 A schematic diagram of the construction process of the assembly geometric model provided in the embodiment of the present application;

[0021] Figure 4 A schematic diagram of a flow chart of a test resonance interval calibration method provided in an embodiment of the present application;

[0022] Figure 5 A schematic diagram of a simulation evaluation process provided in an embodiment of the present application;

[0023] Figure 6 A schematic diagram of the structure of a bolt slip safety factor testing device provided in an embodiment of the present application;

[0024] Figure 7 A schematic diagram of the hardware structure of an electronic device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0025] The features and exemplary embodiments of various aspects of the present invention will be described in detail below. In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present invention, rather than to limit the present invention. For those skilled in the art, the present invention can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present invention by illustrating examples of the present invention.

[0026] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0027] In the automobile manufacturing process, there are many parts in the car that are fastened by bolts. Different parts have different characteristics, and the corresponding bolt slip safety factors are also different. For example, for the design of heat shields in hybrid vehicle powertrains, thin-walled parts are usually used as heat shields. During the long-term working process, due to their thin-walled characteristics, they are more likely to have bolt loosening problems than other parts fastened by bolts. If you only rely on current experience to select the appropriate type of bolt-fastened heat shield, it is easy for the bolts to loosen, which will cause a series of potential risks.

[0028] In response to the above problems, the present application provides a bolt slip safety factor testing scheme, through which the bolt slip safety factor is calibrated and a special bolt slip safety factor is set for specific thin-walled parts in the vehicle. In this way, the accurate bolt slip safety factor can be used to configure suitable types of bolts for thin-walled parts, thereby preventing the possibility of bolt loosening and improving vehicle safety.

[0029] The technical solution of the present application is described in detail below through specific embodiments. It should be noted that the following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0030] Figure 1A A schematic diagram of the structure of the test system provided in the embodiment of the present application, such as Figure 1A As shown, it includes a sensor 11, a test fixture 12, a vibration table 13, a test device 14 and an electronic device 15.

[0031] The test fixture 12 is equipped with a test part to be subjected to a vibration test, and the test part is fixed to the test fixture 12 by bolts. The test fixture 12 is fixedly arranged on a vibration table 13 .

[0032] The sensor 11 is disposed on the test part, and the test equipment 14 is connected to the sensor 11 and the electronic equipment 15 respectively.

[0033] The vibration table 13 drives the test fixture 12 and the test part set on the test fixture to vibrate according to the set frequency. The sensor 11 collects the vibration data of the test part and transmits it to the electronic device 15. The electronic device 15 is used to determine whether the test part resonates according to the vibration data.

[0034] Exemplarily, the electronic device may be a computer, a mobile terminal or a cloud server, etc. Exemplarily, the test part may be a heat shield.

[0035] In this embodiment, the test fixture is provided with at least one slide groove extending in different extension directions, and the slide groove is provided with a bracket that can slide in the extension direction, and the bracket is used to bolt and fix different types of test parts.

[0036] The bracket may be provided with threaded holes and other components for bolt fixing, and the test part is fixed to the bracket by bolts.

[0037] In order to make the test fixture compatible with test parts of various sizes, the fixed position point can be adjusted by controlling the bracket to slide on the slide. For example, when the bracket slides to the starting position or the end position of the slide, some larger test parts can be fixed on the bracket. In addition, since the test part is fixed to the bracket by bolts, the fixed position point of the test part can be adjusted by sliding the bracket.

[0038] For example, Figure 1B The schematic diagram of the structure of the test tool provided in the embodiment of the present application at different viewing angles is as follows: Figure 1BAs shown in (a), the test fixture 12 also includes a first slide groove 111 and a second slide groove 112. The first slide groove 111 extends in a first direction by a preset first distance, and the second slide groove 112 extends in a second direction different from the first direction by a preset second distance.

[0039] Exemplarily, the first direction is perpendicular to the second direction. Figure 1B As shown in (a), the first direction may be upward, and the second direction may be leftward.

[0040] In this embodiment, each chute may be provided with a bracket 114, or may not be provided with a bracket, that is, the bracket is detachably mounted on the chute. By mounting the bracket on the chute and then controlling the bracket to move upward and downward, or to move left or right, various test parts 115 of different sizes and shapes can be adapted.

[0041] Exemplarily, the test part may be a thin-walled part, such as a heat shield in a hybrid vehicle powertrain.

[0042] In this embodiment, different test fixtures can be matched with different heat shields, and the test fixtures are also replaceable, and the slide grooves on different test fixtures are different, for example, the slide groove directions and the number of slide grooves are different.

[0043] Further, continue to refer to the above Figure 1B In (a) and (d), in order to better adapt test parts of different sizes to be assembled on the test tooling, the test tooling also includes a third slide groove 113. After the third slide groove 113 extends in the first direction for a preset third distance, it continues to extend in the second direction for a preset fourth distance.

[0044] In this embodiment, the extension distances of the first slide slot, the second slide slot, and the third slide slot can be freely configured, but they should not be extended beyond the entire test fixture, which may easily cause the bracket to detach from the test fixture. However, in some embodiments, in order to facilitate the removal of the bracket, the slide slot can be extended beyond the test fixture, so that the bracket can be directly removed from the test fixture while moving along the slide slot.

[0045] In addition, in some embodiments, the sizes of the brackets provided on each chute are different from each other, wherein the size may refer to the length, width and height of the brackets.

[0046] For example, the heights of the brackets on each slide are different, so that some test parts with height fluctuations can be installed, making the test fixture more compatible.

[0047] In addition, in some embodiments, continue to refer to the above Figure 1BIn (d), a fourth slide groove is provided on the bracket, and the extension direction of the fourth slide groove is different from the extension direction of the slide groove of the test fixture, and the bracket can slide relative to the slide groove along the extension direction of the fourth slide groove.

[0048] In this embodiment, the size of the slide groove on the bracket and the slide groove on the test fixture can be the same, which makes it easy to fix the bracket to the test fixture by fasteners such as bolts.

[0049] Among them, in addition to being able to slide on the slide groove, the bracket can also be configured with a slide groove. When the slide groove of the bracket and the slide groove on the test tooling are perpendicular to each other, the bracket can actually move along the slide groove on the test tooling, and can also move through its own slide groove. This can improve the adjustment flexibility of the fixed position and provide more abundant fixed position points for the test tooling to fix.

[0050] Exemplarily, the extension direction of the fourth slide groove is perpendicular to the extension direction of the slide groove of the test fixture.

[0051] In addition, in some embodiments, continue to refer to the above Figure 1A and Figure 1B In (c), the test fixture is set on the vibration table by fixing bolts 116. When the vibration table vibrates according to the set frequency, it drives the test fixture and the test part set on the bracket of the test fixture to vibrate.

[0052] In this embodiment, taking the heat shield as the test part as an example, due to the thin-walled characteristics of the heat shield, a large installation tolerance will be generated, so the bolts are prone to loosening during the vibration process. Therefore, it is necessary to establish a vibration database for such parts in order to quantify the anti-slip safety factors of different types of heat shields.

[0053] In this embodiment, a complete test equipment for testing the database is formed by a vibration table, a test instrument, a sensor, a tooling and a computer. The tooling is fixed to the vibration table by four bolts, and the heat shield is fixed to the tooling by bolts through a combination of different brackets according to different shapes. Sensors can be installed in different areas of the heat shield, and relevant vibration test data can be obtained by connecting the vibration table, the sensor and the test equipment. A simulation model is established synchronously with the tooling to calibrate the test and simulation data.

[0054] Figure 2 A schematic diagram of a flow chart of a bolt slip safety factor testing method provided in an embodiment of the present application, such as Figure 2 As shown, the method may specifically include the following steps:

[0055] Step S210: Obtain the assembly geometric model of the test fixture and the test part, and establish a vibration simulation model, wherein the test part can be assembled on the test fixture by initial bolts of an initial model.

[0056] In this embodiment, referring to the above Figure 1A The test part can be assembled on the test fixture by various types of bolts. The fixing points of the bolts can be adjusted according to the different characteristics of the test part, such as size and thickness.

[0057] For example, taking the heat shield mentioned above as the test part, first determine the fixed point position of the heat shield on the test fixture. The fixed point is usually a bolt hole or a threaded hole used to fix the heat shield on the test fixture. The position of the fixed point (including coordinates and angle information) can be accurately measured using a measuring tool.

[0058] Secondly, the relevant software can be used to create the assembly geometry model between the test fixture and the test part based on the measured fixed point position and the actual size of the heat shield. For heat shields with complex shapes or structures, equipment such as 3D scanners can be used to collect surface data to improve the accuracy of the assembly geometry model.

[0059] In this embodiment, after the assembly geometry model is established, appropriate constraints can be added to simulate the actual installation state of the heat shield on the test fixture. For example, the constraints may include bolt connection, fixture fixation, etc. In addition, according to the test requirements, corresponding loads or boundary conditions can be applied to simulate the stress conditions of the heat shield in the actual working environment.

[0060] Among them, finite element analysis software can be used to perform structural simulation analysis on the established assembly geometry model. Through simulation analysis, the deformation and stress distribution of the heat shield under stress can be predicted. As an evaluation result, the previous assembly geometry model can be further optimized (for example, adjusting the position of the fixing point, adjusting the thickness or material of the heat shield, etc.).

[0061] Step S220: Determine candidate bolts of candidate models according to the vibration simulation model and the bolt slip safety factor of the test part.

[0062] In this embodiment, continuing to take the test part as an example of a heat shield, after establishing a vibration simulation model, the stress conditions between the bolts and the heat shield in the actual working environment can be obtained through simulation analysis. For example, in order to understand the stress conditions between the bolts and the heat shield, the reaction force of the heat shield on the bolts during resonance (hereinafter referred to as the simulated support reaction force) can be analyzed, and at least one candidate bolt of a candidate model can be determined through the simulated support reaction force and the initial bolt slip safety factor. Among them, the analysis of the reaction force on the bolts during resonance of the heat shield is mainly because the vibration amplitude of the heat shield during resonance is the largest relative to normal times, and the reaction force on the bolts can reach the maximum value, thereby further determining the reaction force value range.

[0063] In this embodiment, when determining the candidate bolts of the candidate model, an empirical value may be taken as the bolt slip safety factor of the test part, and the empirical value may be further calibrated and updated later.

[0064] In some embodiments, the candidate model can be determined based on the simulated support reaction force of the test part during the vibration simulation test of the vibration simulation model and the bolt slip safety factor which is an empirical value. Subsequently, the candidate bolts of the candidate model are tested and the test results (such as whether the candidate bolts are loose) are obtained to further calibrate the bolt slip safety factor which was originally an empirical value.

[0065] Among them, the slip safety factor is an important indicator to measure the safety of bolt connections, which indicates the ratio of the maximum load that the bolt can withstand before sliding to the actual working load. Through the slip safety factor and the simulated support reaction force, the main load type (such as tension only, shear only, or a combination of tension and shear) and the size of the load that the bolt will withstand can be determined, so as to determine the model or specification of the candidate bolt.

[0066] For example, a table can be pre-built, and the corresponding candidate bolt model can be found from the table by simulating the empirical values ​​of the support reaction force and the bolt slip safety factor. For example, a vibration simulation model is constructed using a small single-layer metal heat shield as a test part, and the empirical value of the bolt anti-slip safety factor is 5, and the corresponding candidate bolt model can be M6.

[0067] Step S230: when the test part is assembled on the test fixture according to the candidate bolts of the candidate models and the assembly geometric model, the test fixture is controlled to vibrate according to a set frequency range to obtain the connection status between the candidate bolts and the test part at different times.

[0068] In this embodiment, the connection state between the candidate bolt and the test part can be used to indicate whether the candidate bolt has entered a loose state from a tightened state. For example, after the candidate bolt is screwed into the bolt hole and the test part is fixed, if the candidate bolt is found to be automatically screwed out of the threaded hole during the vibration process, it means that the candidate bolt has entered a loose state.

[0069] In this embodiment, the set frequency interval may include a resonance frequency, so that the maximum vibration amplitude of the test part can be obtained to check whether the candidate bolt will loosen under resonance.

[0070] Step S240: updating the bolt slip safety factor of the test part according to the connection status between the candidate bolt and the test part at different times.

[0071] In this embodiment, during the continuous vibration of the test fixture, if the candidate bolt becomes loose within a very short vibration duration, it means that the original bolt slip safety factor, which is an empirical value, is inaccurate and needs further calibration optimization. In addition, if the candidate bolt does not become loose within a long vibration duration, it means that the original bolt slip safety factor, which is an empirical value, is relatively accurate and can be recorded in a table for subsequent reference.

[0072] In an embodiment of the present application, by recording the vibration data of the test part during the test and combining it with the simulation data, the bolt slip safety factor of the test part can be accurately calculated, thereby improving the accuracy of the bolt slip safety factor and avoiding the risk of over-design and under-design of the bolt model when selecting bolts to fix the test part.

[0073] Furthermore, in some embodiments, after calibrating the bolt slip safety factor, the optimal bolt model of the test part can be determined based on the calibrated and updated bolt slip safety factor and the simulated support reaction force in the vibration simulation model. By fixing the test part with the optimal bolt model, the stability of the test part can be improved, thereby avoiding the problem of bolt loosening due to the thin-walled characteristics of the parts during the endurance operation of the vehicle.

[0074] In some embodiments, Figure 3 A schematic diagram of the construction process of the assembly geometric model provided in the embodiment of the present application is shown in FIG. Figure 3 As shown, it may specifically include the following steps:

[0075] Step S310: Acquire the property information of the test part and the fixed position point of the test part on the test tooling.

[0076] The attribute information includes at least one of the size, number of layers and thickness of the test part.

[0077] Step S320: constructing an assembly geometric model according to at least one of the size, number of layers and thickness of the test part and the fixed position points.

[0078] In this embodiment, the test part is taken as the heat shield mentioned above. In order to facilitate heat dissipation, the heat shield is usually made of metal. In addition, the heat shield can be divided into multiple layers, such as a single-layer metal heat shield, a double-layer metal heat shield, and a triple-layer metal heat shield. The more layers there are, the thicker the heat shield is. By understanding the material properties of the heat shield, a more realistic vibration simulation model can be established.

[0079] In addition, based on the fact that the heat insulation cover may be fixed to different parts, the sizes of the heat insulation cover may also be different. For example, the heat insulation cover may be divided into a small heat insulation cover, a medium heat insulation cover, and a large heat insulation cover.

[0080] In this embodiment, the heat shield can be classified according to the number of layers and size of the heat shield. For example, the heat shield can be divided into a small single-layer metal heat shield, a medium single-layer metal heat shield, a large single-layer metal heat shield, a small double-layer metal heat shield, a medium double-layer metal heat shield and a small three-layer composite metal heat shield. Different types of heat shields have different corresponding resonant frequency ranges.

[0081] In this embodiment, the assembly geometric model may also be updated by adjusting the attribute information and the fixed position points.

[0082] In the embodiment of the present application, by accurately acquiring the property information and fixed position points of the test parts, it is possible to ensure that the relevant physical parameters are taken into account in the process of establishing the assembly geometric model, thereby improving the accuracy of the assembly model.

[0083] As mentioned above, the test fixture can vibrate according to a set frequency range to drive the test part to vibrate. In some embodiments, Figure 4 A schematic diagram of the experimental resonance interval calibration method provided in the embodiment of the present application is shown in FIG. Figure 4 As shown, the method may include the following steps:

[0084] Step S410: performing vibration simulation according to the vibration simulation model to obtain a simulation resonance range of the test part;

[0085] Step 420: When the test part is assembled on the test fixture according to the candidate bolts and the assembly geometry model, the test fixture is controlled to perform a sweep frequency vibration test in a simulated resonance range to determine a test resonance frequency when the test part resonates;

[0086] Step 430: Obtaining the resonance range of the test part based on the test resonance frequency;

[0087] Step 440: Determine the resonance interval as the set frequency interval.

[0088] In this embodiment, different types of test parts have different simulation resonance ranges. For example, a small single-layer metal heat shield has a simulation resonance range of about 100 Hz, a medium single-layer metal heat shield has a simulation resonance range of about 90 Hz, and a large single-layer metal heat shield has a simulation resonance range of about 80 Hz.

[0089] Among them, after the simulation resonance ranges of different categories of test parts are obtained through vibration simulation by the vibration simulation model, they can be recorded in a table, so that when the simulation resonance ranges of the same category of test parts are determined later, the table can be directly looked up.

[0090] In this embodiment, the test fixture can perform sweep frequency vibration within the simulated resonance range, and determine through experiments at which specific vibration frequency the test part resonates, thereby determining the test resonance frequency.

[0091] For example, taking the simulation resonance interval of about 100 Hz as an example, the test fixture can be controlled to drive the test part to vibrate at a vibration frequency of 100 Hz to determine whether the test part resonates. If the test part resonates, 100 Hz is the experimental resonance frequency. If the test part does not resonate, for example, the test part is continued to be driven to vibrate at a vibration frequency of 101 Hz to determine whether the test part resonates, thereby finding the single experimental resonance frequency of the test part by frequency sweeping.

[0092] In this embodiment, the resonance range and direction and other working conditions required for the durability test can also be calibrated based on the vibration simulation results, which can improve efficiency, quickly find the resonance range, and avoid inaccuracy in the resonance range.

[0093] For example, Figure 5 A schematic diagram of the simulation evaluation process provided in the embodiment of the present application is shown in FIG. Figure 5 As shown, it includes the following steps: Step 51: finite element structure simulation. Step 52: heat shield test model modeling. Step 53: sweep frequency vibration excitation load. Step 54: test sweep frequency. Step 55: modal and vibration simulation. Step 56: vibration frequency determination. Step 57: modal, vibration shape and support reaction force evaluation. Step 58: adjust at least one of the fixing point, material or thickness, step S59: optimize the assembly geometry model. Step 510: determine the bolt model specification.

[0094] In this embodiment, by combining simulation with experiment, since the different constraint boundaries when the heat shield is fixed on different parts will affect the natural frequency of the heat shield assembly, and the traditional component-level simulation does not consider the problem of constrained opponent parts in the assembly-level test. In this embodiment, by modeling the test fixture built for the experiment, the assembly frequency under different states can be reproduced, the accuracy of the test results can be calibrated, and the simulation can be mutually verified through the sweep frequency test, and then the durability vibration test is performed on the first few frequencies, which can test the durability performance of the heat shield in a targeted manner.

[0095] In this embodiment, finite element structural simulation is to simulate the real physical system (such as the assembly geometry model and the corresponding load conditions) by using mathematical approximation methods. Among them, mode refers to the natural vibration mode of a structure at a specific frequency. Each mode has its specific natural frequency (also called characteristic frequency) and corresponding vibration mode. The vibration mode refers to the mode of relative displacement of each point on the structure under a given mode. It describes the relative motion relationship between the parts of the structure when it vibrates.

[0096] In the embodiment of the present application, the resonance range and direction and other working conditions required for the durability test are calibrated in combination with the simulation results, which can improve the test efficiency and quickly find the resonance range of the test parts. At the same time, the inaccuracy of the resonance range is avoided through mutual verification of simulation and test.

[0097] In some embodiments, there may be multiple candidate bolts of candidate models, such as bolts of candidate model M6, bolts of candidate model M5, and bolts of candidate model M4, etc. Candidate bolts of different models may be used to fix the test part, and then the test fixture may be controlled to vibrate according to a set frequency range to obtain the connection state between each candidate bolt of each model and the test part.

[0098] In this embodiment, after a recommended bolt model is determined based on the simulated support reaction force and the bolt slip safety factor, other bolt models that are smaller than the recommended bolt model can be obtained, and then the recommended bolt model and other bolt models are determined as candidate models.

[0099] Illustratively, Table 1 below is a vibration data table provided in an embodiment of the present application. As shown in Table 1 below, the bolt slip safety factor can be calibrated through simulation and testing.

[0100] Table 1

[0101]

[0102] Referring to Table 1 above, the simulation recommended model is obtained by simulating the support reaction force and the bolt slip safety factor with an empirical value. The simulation recommended model and a smaller model bolt are tested to examine the looseness in the resonance range. Different bolts and washers are tested iteratively, and the results are recorded to calibrate the anti-slip safety factor. Among them, the simulation recommended model is the recommended bolt model. Taking the simulation recommended model M6 as an example, other bolt models can be M5, which is smaller than M6.

[0103] In addition, in this embodiment, in order to obtain accurate test data and accurately grasp the best bolt matching model of the test part, washers, such as wire washers and rubber washers, can be added between the bolt and the test part. The wire washers and rubber washers can span between two adjacent bolt models, so as to more accurately find the best bolt matching model. For example, referring to Table 6 above, by using M5+rubber washers and M5+wire washers for testing, it is found that they also become loose, so the M5 bolt model is not suitable as the best matching model.

[0104] In an embodiment of the present application, by testing the recommended bolt model and other smaller bolt models, examining their looseness within the resonance range, iteratively testing different bolts and washers, and recording the results to calibrate the bolt slip safety factor, the calibration accuracy can be improved.

[0105] Further, in some embodiments, when calibrating the bolt slip safety factor whose original value is an empirical value, the bolt slip safety factor can be adjusted and updated by continuing to refer to the data in Table 1 above through the following steps:

[0106] Step 21: When the candidate bolt is loosened within the preset vibration duration, the bolt slip safety factor is updated to the first bolt slip safety factor.

[0107] Step 22: When the candidate bolt is not loosened within the preset vibration duration, the bolt slip safety factor is kept unchanged or updated to a second bolt slip safety factor.

[0108] Among them, the first bolt slip safety factor is greater than the bolt slip safety factor; the second bolt slip safety factor is less than the bolt slip safety factor.

[0109] In this embodiment, the preset vibration duration can be a process standard value, such as 100 hours. Referring to Table 1 above, the M6 ​​bolts are still not loosened after the vibration duration is 100 hours, while the M5 bolts will still loosen in less than 100 hours regardless of whether they are equipped with wire washers or rubber washers. It can be seen that the M5 bolts are not suitable for fixing the test parts. If the empirical value of the original bolt slip safety factor is 5, then this value can be kept unchanged.

[0110] In addition, if the M6 ​​bolts become loose after 100 hours of continuous vibration, it means that the original bolt slip safety factor is too small. For example, if the experience value of the original bolt slip safety factor is 5, the bolt slip safety factor can be increased. In this way, when the bolts are used to fix the test parts in the future, the appropriate bolt model will be selected according to the updated bolt slip safety factor to improve the reliability of the test parts.

[0111] Furthermore, in other embodiments, when the bolts of the recommended bolt model have not loosened within the preset vibration duration, it can be determined whether the bolts of other bolt models have loosened within the preset vibration duration; then, when the bolts of other bolt models have not loosened, the bolt slip safety factor is updated to the second bolt slip safety factor; or when the bolts of other bolt models are loose, the bolt slip safety factor is kept unchanged.

[0112] In this embodiment, the M6 ​​model is used as the recommended bolt model and the M5 model is used as an example of other bolt models. If it is found in the test that neither the M6 ​​model bolt nor the M5 model bolt is loose, then the M5 model can actually be used as the best matching model for the test part. At this time, the original bolt slip safety factor can be reduced.

[0113] In the embodiment of the present application, the manufacturing tolerances and installation tolerances of different heat shields are comprehensively considered through vibration tests, and the bolt slip safety factor of the heat shield is quantified for bolt loosening. Therefore, when the heat shield is subsequently fixed, a suitable fixing method and fixing bolt model can be reasonably selected based on the calibrated bolt slip safety factor, thereby improving the reliability of the heat shield and the safety of the vehicle.

[0114] The following is an embodiment of the device of the present application, which can be used to execute the embodiment of the method of the present application. For details not disclosed in the embodiment of the device of the present application, please refer to the embodiment of the method of the present application.

[0115] Figure 6 A schematic diagram of the structure of a bolt slip safety factor testing device provided in an embodiment of the present application is shown in FIG. Figure 6 As shown, the bolt slip safety factor testing device 600 includes an acquisition module 610 , a determination module 620 , a detection module 630 and an update module 640 .

[0116] Among them, the acquisition module 610 is used to obtain the assembly geometry model of the test fixture and the test part, and establish a vibration simulation model. The determination module 620 is used to determine the candidate bolts of the candidate model according to the vibration simulation model and the bolt slip safety factor of the test part. The detection module 630 is used to control the test fixture to vibrate according to a set frequency range when the test part is assembled on the test fixture according to the candidate bolts of the candidate model and the assembly geometry model, and obtain the connection status between the candidate bolts and the test part at different times. The update module 640 is used to update the bolt slip safety factor of the test part according to the connection status between the candidate bolts and the test part at different times.

[0117] Optionally, it also includes a construction module for obtaining attribute information of the test part and fixed position points of the test part on the test tooling, the attribute information including at least one of the size, number of layers and thickness of the test part; and constructing an assembly geometry model based on at least one of the size, number of layers and thickness of the test part and the fixed position points.

[0118] Optionally, it also includes a frequency determination module, which is used to perform vibration simulation according to a vibration simulation model to obtain a simulated resonance range of the test part; when the test part is assembled on a test fixture according to the candidate bolts and the assembly geometry model, the test fixture is controlled to perform a swept frequency vibration test in the simulated resonance range to determine the test resonance frequency when the test part resonates; based on the test resonance frequency, the resonance range of the test part is obtained; and the resonance range is determined as a set frequency range.

[0119] Optionally, the determination module can be specifically used to: obtain the simulated support reaction force of the vibration simulation model when performing a vibration simulation test; and determine the candidate model according to the simulated support reaction force and the bolt slip safety factor.

[0120] Optionally, the determination module can be specifically used to: determine the recommended bolt model based on the simulated support reaction force and the bolt sliding safety factor; obtain other bolt models that are smaller than the recommended bolt model; and determine the recommended bolt model and other bolt models as candidate models.

[0121] Optionally, the updating module may be specifically used to: when the candidate bolt is loosened within a preset vibration duration, update the bolt slip safety factor to a first bolt slip safety factor, where the first bolt slip safety factor is greater than the bolt slip safety factor;

[0122] When the candidate bolt is not loosened within the preset vibration duration, the bolt slip safety factor is kept unchanged or updated to a second bolt slip safety factor, which is smaller than the bolt slip safety factor.

[0123] Optionally, a model determination module is also included, which is used to determine the bolt model of the test part based on the updated bolt slip safety factor and vibration simulation model.

[0124] Optionally, the test part is a heat shield.

[0125] The device provided in the embodiment of the present application can be used to execute the method in the above embodiment. Its implementation principle and technical effect are similar and will not be repeated here.

[0126] It should be noted that it should be understood that the division of the various modules of the above device is only a division of logical functions. In actual implementation, they can be fully or partially integrated into one physical entity, or they can be physically separated. And these modules can all be implemented in the form of software called by processing elements; they can also be all implemented in the form of hardware; some modules can also be implemented in the form of software called by processing elements, and some modules can be implemented in the form of hardware. For example, the determination module can be a separately established processing element, or it can be integrated in a chip of the above device. In addition, it can also be stored in the memory of the above device in the form of program code, and called and executed by a processing element of the above device. The implementation of other modules is similar. In addition, these modules can be fully or partially integrated together, or they can be implemented independently. The processing element here can be an integrated circuit with signal processing capabilities. In the implementation process, each step of the above method or each module above can be completed by an integrated logic circuit of hardware in the processor element or instructions in the form of software.

[0127] Figure 7 Schematic diagram of the hardware structure of the electronic device provided by the embodiment of the present invention. Figure 7 As shown, the electronic device 700 may include a processor 701 and a memory 702 storing computer program instructions.

[0128] Specifically, the processor 701 may include a central processing unit (CPU), or an application specific integrated circuit (ASIC), or may be configured to implement one or more integrated circuits of the embodiment of the present invention.

[0129] The memory 702 may include a large capacity memory for data or instructions. By way of example and not limitation, the memory 702 may include a hard disk drive (HDD), a floppy disk drive, a flash memory, an optical disk, a magneto-optical disk, a magnetic tape, or a universal serial bus (USB) drive or a combination of two or more of these. In one example, the memory 702 may include a removable or non-removable (or fixed) medium, or the memory 702 is a non-volatile solid-state memory. The memory 702 may be inside or outside the integrated gateway disaster recovery device.

[0130] In one example, the memory 702 may be a read-only memory (ROM). In one example, the ROM may be a mask-programmed ROM, a programmable ROM (PROM), an erasable PROM (EPROM), an electrically erasable PROM (EEPROM), an electrically rewritable ROM (EAROM), or a flash memory, or a combination of two or more of these.

[0131] The memory 702 may include a read-only memory (ROM), a random access memory (RAM), a magnetic disk storage medium device, an optical storage medium device, a flash memory device, an electrical, optical or other physical / tangible memory storage device. Thus, in general, the memory includes one or more tangible (non-transitory) computer-readable storage media (e.g., a memory device) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described with reference to the method according to an aspect of the present disclosure.

[0132] The processor 701 implements the method in the above embodiment by reading and executing the computer program instructions stored in the memory 702 .

[0133] In one example, the electronic device 700 may further include a communication interface 703 and a bus 704. Figure 7As shown, the processor 701, the memory 702, and the communication interface 703 are connected through the bus 704 and complete the communication between each other. The communication interface 703 is mainly used to realize the communication between the modules, devices, units and / or devices in the embodiment of the present invention. The bus 704 includes hardware, software or both, and couples the components of the online data traffic billing device to each other. For example and not limitation, the bus may include an Accelerated Graphics Port (AGP) or other graphics bus, an Extended Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), a Hyper Transport (HT) interconnection, an Industry Standard Architecture (ISA) bus, an InfiniBand interconnection, a Low Pin Count (LPC) bus, a memory bus, a Micro Channel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association Local (VLB) bus or other suitable buses or a combination of two or more of these. Bus 304 may include one or more buses, where appropriate. Although embodiments of the present invention describe and illustrate a particular bus, the present invention contemplates any suitable bus or interconnect.

[0134] In addition, in combination with the method in the above embodiment, the embodiment of the present invention can provide a computer storage medium for implementation. The computer storage medium stores computer program instructions; when the computer program instructions are executed by a processor, any one of the methods in the above embodiment is implemented.

[0135] An embodiment of the present application also provides a computer program product, including a computer program, which implements any one of the methods in the above embodiments when the computer program is processed and executed.

[0136] It should be clear that the present invention is not limited to the specific configuration and processing described above and shown in the figures. For the sake of simplicity, a detailed description of the known method is omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present invention is not limited to the specific steps described and shown, and those skilled in the art can make various changes, modifications and additions, or change the order between the steps after understanding the spirit of the present invention.

[0137] The functional blocks shown in the structural block diagram described above can be implemented as hardware, software, firmware or a combination thereof. When implemented in hardware, it can be, for example, an electronic circuit, an application specific integrated circuit (Application Specific Integrated Circuit, ASIC), appropriate firmware, plug-in, function card, etc. When implemented in software, the elements of the present invention are programs or code segments used to perform the required tasks. The program or code segment can be stored in a machine-readable medium, or transmitted on a transmission medium or communication link by a data signal carried in a carrier. "Machine-readable medium" may include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, read-only memory (Read-Only Memory, ROM), flash memory, erasable read-only memory (Erasable Read Only Memory, EROM), floppy disks, compact disc read-only memory (Compact Disc Read-Only Memory, CD-ROM), optical discs, hard disks, optical fiber media, radio frequency (Radio Frequency, RF) links, etc. The code segment can be downloaded via a computer network such as the Internet, an intranet, etc.

[0138] It should also be noted that the exemplary embodiments mentioned in the present invention describe some methods or systems based on a series of steps or devices. However, the present invention is not limited to the order of the above steps, that is, the steps can be performed in the order mentioned in the embodiments, or in a different order from the embodiments, or several steps can be performed simultaneously.

[0139] Aspects of the present disclosure are described above with reference to the flowchart and / or block diagram of the method, device (system) and computer program product according to the embodiment of the present disclosure. It should be understood that each box in the flowchart and / or block diagram and the combination of each box in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device to produce a machine so that these instructions executed by the processor of the computer or other programmable data processing device enable the implementation of the function / action specified in one or more boxes of the flowchart and / or block diagram. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field programmable logic circuit. It can also be understood that each box in the block diagram and / or flowchart and the combination of boxes in the block diagram and / or flowchart can also be implemented by dedicated hardware that performs a specified function or action, or can be implemented by a combination of dedicated hardware and computer instructions.

[0140] The above is only a specific implementation of the present invention. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working process of the system, module and unit described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here. It should be understood that the protection scope of the present invention is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be covered within the protection scope of the present invention.

Claims

1. A method for testing bolt slip safety factor, characterized in that: include: Obtain the assembly geometry model of the test fixture and test parts, and establish a vibration simulation model; Determining candidate bolts of candidate models according to the vibration simulation model and the bolt slip safety factor of the test part; When the test part is assembled on the test fixture according to the candidate bolt of the candidate model and the assembly geometric model, the test fixture is controlled to vibrate according to a set frequency range to obtain the connection state between the candidate bolt and the test part at different times; The bolt slip safety factor of the test part is updated according to the connection status between the candidate bolt and the test part at different times.

2. The method according to claim 1, characterized in that Also includes: Acquire attribute information of the test part and a fixed position point of the test part on the test fixture, wherein the attribute information includes at least one of a size, a number of layers, and a thickness of the test part; The assembly geometric model is constructed according to at least one of the size, number of layers and thickness of the test part and the fixed position points.

3. The method according to claim 1, characterized in that: Also includes: Perform vibration simulation according to the vibration simulation model to obtain a simulated resonance range of the test part; When the test part is assembled on the test fixture according to the candidate bolt and the assembly geometric model, controlling the test fixture to perform a frequency sweep vibration test in the simulation resonance range to determine a test resonance frequency when the test part resonates; Based on the test resonance frequency, obtaining a resonance range of the test part; The resonance interval is determined as the set frequency interval.

4. The method according to claim 1, characterized in that The determining of the candidate model comprises: Obtaining a simulated support reaction force when the vibration simulation model is subjected to a vibration simulation test; The candidate model is determined according to the simulated support reaction force and the bolt slip safety factor.

5. The method according to claim 4, characterized in that The determining the candidate model according to the simulated support reaction force and the bolt slip safety factor includes: Determine the recommended bolt model according to the simulated support reaction force and the bolt sliding safety factor; Obtain other bolt models whose models are smaller than the recommended bolt models; The recommended bolt model and other bolt models are determined as the candidate models.

6. The method according to claim 5, characterized in that The updating of the bolt slip safety factor according to the connection states between the candidate bolts and the test part at different times includes: When the candidate bolt is loosened within the preset vibration duration, updating the bolt slip safety factor to a first bolt slip safety factor, wherein the first bolt slip safety factor is greater than the bolt slip safety factor; When the candidate bolt does not loosen within the preset vibration duration, the bolt slip safety factor is kept unchanged or updated to a second bolt slip safety factor, which is smaller than the bolt slip safety factor.

7. The method according to any one of claims 1 to 6, characterized in that Also includes: The bolt model of the test part is determined according to the updated bolt slip safety factor and the vibration simulation model.

8. The method according to any one of claims 1 to 6, characterized in that The test part is a heat shield.

9. A test tool, characterized in that: The test fixture is provided with at least one slide groove extending in different extension directions, and the slide groove is provided with a bracket that can slide in the extension direction, and the bracket is used to bolt and fix different types of test parts.

10. A testing system, characterized in that: The device comprises a sensor, a vibration table, a test device, an electronic device and the test fixture according to claim 9, wherein the test fixture is arranged on the vibration table, the test part is arranged on the test fixture by bolts, the sensor is arranged on the test part, and the test device is connected to the sensor and the electronic device respectively; The vibration table is used to drive the test fixture and the test parts arranged on the test fixture to vibrate according to a set frequency; The sensor is used to collect vibration data of the test part and transmit it to the electronic device; The electronic device is used to determine whether the test part resonates based on the vibration data.

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