Benchmarking method, device, power exchange equipment and medium for spring unit stiffness between pin holes

Abstract

The present invention discloses a method for benchmarking the stiffness of a spring unit between pin holes applied to a swapping module frame, a benchmarking device, a swapping device, and a computer-readable storage medium. The benchmarking method includes: obtaining a first test main frequency and a second test main frequency of the swapping module frame; building a finite element model of the swapping module frame, and establishing a spring unit between the nodes of the first surface mesh of the positioning pin mating surface and the second surface mesh of the positioning hole mating surface; obtaining the axial stiffness of the spring unit; calculating a first calculated main frequency and a second calculated main frequency by using the finite element model of the swapping module frame and the axial stiffness of the spring unit; when the first calculated main frequency is within a first set range and the second calculated main frequency is within a second set range, determining the axial stiffness of the spring unit as the axial stiffness of the spring unit used in modal and / or random vibration simulation. The above benchmarking method can accurately simulate the modal and / or random vibration simulation of the swapping module frame.

Description

Technical Field

[0001] The present invention relates to the technical field of battery swapping equipment, and particularly to a method and device for benchmarking the stiffness of a spring unit between pin holes applied to a battery swapping module frame, a battery swapping device, and a computer-readable storage medium. Background Art

[0002] In recent years, the state has given a lot of support to the development of new energy vehicles, and electric heavy trucks, especially those with the battery swapping mode, have become a new development direction. The battery swapping module is an important object for battery swapping operations of battery swapping vehicles and an important part of battery swapping vehicles. Usually, the entire battery swapping module frame is composed of an upper upper frame, a lower bottom bracket, and a locking mechanism, and there is a positioning pin hole structure between the upper upper frame and the lower bottom bracket. Each manufacturer needs to analyze and test the strength and vibration durability performance of the battery swapping module to meet the long-term vibration durability performance of the battery swapping module during vehicle driving. Finite element simulation analysis is a very important verification means in the development process of the battery swapping module.

[0003] Generally, the battery swapping module frame needs to perform random vibration simulation. The premise of random vibration simulation is to perform modal simulation analysis. In the modal analysis of the battery swapping module, there is a certain very small gap between the positioning pin and the positioning hole. Modal analysis is a linear analysis method and cannot establish a frictional contact relationship between the positioning pin and the positioning hole to ensure the establishment of a force transmission relationship between the mating surfaces of the two during the calculation process. Therefore, there are technical difficulties in finite element modeling for the pin hole structure. There are generally two treatment methods for the pin hole structure: one is to assume that there is no contact relationship between the positioning pin and the positioning hole, that is, no mechanical relationship, and they can penetrate each other; the other is to assume that a bonded constraint relationship is adopted between the positioning pin and the positioning hole, and there is no relative movement between the two. As is well known, the pin hole structure generally can move relative to each other along the axial direction and can be mutually constrained along the radial direction. Therefore, both of these treatment methods deviate greatly from the engineering reality, affecting the accuracy of the modal analysis of the entire battery swapping module and further affecting the results of random vibration analysis. Summary of the Invention

[0004] Embodiments of the present invention provide a method and device for benchmarking the stiffness of a spring unit between pin holes applied to a battery swapping module frame, a battery swapping device, and a computer-readable storage medium.

[0005] Embodiments of the present invention provide a method for benchmarking the stiffness of a spring unit between pin holes applied to a battery swapping module frame. The battery swapping module frame includes an upper frame, a bottom bracket, and a positioning structure. The positioning structure includes a positioning pin and a positioning hole. The positioning pin is connected to the bottom bracket, and the positioning hole is connected to the upper frame. The upper frame and the bottom bracket achieve positioning cooperation in the axial direction of the positioning structure through the positioning pin and the positioning hole;

[0006] The alignment method includes:

[0007] Perform a sweep frequency test on the battery swapping module frame to obtain the first test main frequency and the second test main frequency of the battery swapping module frame, and the directions where the first test main frequency and the second test main frequency are located are different directions in the radial direction of the positioning structure;

[0008] Build a finite element model of the battery swapping module frame. Among them, the finite element model of the positioning pin includes the first surface mesh of the positioning pin mating surface, and the finite element model of the positioning hole includes the second surface mesh of the positioning hole mating surface. Establish spring elements between the nodes of the first surface mesh and the nodes of the second surface mesh;

[0009] Obtain the axial stiffness of the spring element;

[0010] Calculate the first calculated main frequency and the second calculated main frequency by using the finite element model of the battery swapping module frame and the axial stiffness of the spring element. The direction where the first calculated main frequency is located is the same as the direction where the first test main frequency is located, and the direction where the second calculated main frequency is located is the same as the direction where the second test main frequency is located;

[0011] When the first calculated main frequency is within the first set range and the second calculated main frequency is within the second set range, determine the axial stiffness of the spring element as the axial stiffness of the spring element used in modal and / or random vibration simulation. The first set range is determined according to the first test main frequency, and the second set range is determined according to the second test main frequency.

[0012] In the above alignment method, the spring element connects the nodes of the first surface mesh of the positioning pin mating surface and the nodes of the second surface mesh of the positioning hole mating surface, and builds the relative movement relationship between the positioning pin and the positioning hole in the axial and radial directions of the positioning structure. By determining the final axial stiffness of the spring element, the relative movement between the positioning pin and the positioning hole in the axial and radial directions of the positioning structure can be accurately simulated, and then the modal and / or random vibration simulation of the battery swapping module frame can be accurately simulated.

[0013] In some embodiments, the radial direction of the positioning structure includes the X direction and the Y direction. Performing a sweep frequency test on the battery swapping module frame to obtain the first test main frequency and the second test main frequency of the battery swapping module frame includes:

[0014] Fix the battery swapping module frame on a horizontal vibration table through a tooling, install a control sensor on the tooling, and install a monitoring sensor on the battery swapping module frame;

[0015] Perform a sweep frequency test in the X direction and the Y direction respectively using the horizontal vibration table, and obtain a frequency-acceleration test curve through the test data output by the control sensor and the monitoring sensor;

[0016] Obtain the first test main frequency and the second test main frequency according to the test curve. The direction where the first test main frequency is located is the X direction, and the direction where the second test main frequency is located is the Y direction.

[0017] In some embodiments, the positioning pin includes a first non-mating surface, a positioning pin mating surface, and a second non-mating surface. The positioning pin mating surface is located between the first non-mating surface and the second non-mating surface, and the positioning hole includes a positioning hole mating surface that has a clearance fit with the positioning pin mating surface;

[0018] Building the finite element model of the battery swapping module framework includes:

[0019] Divide the positioning pin and the positioning hole into polyhedron meshes to obtain the first surface mesh and the second surface mesh. The number and position of the nodes of the first surface mesh correspond one-to-one with the number and position of the nodes of the second surface mesh in the axial and circumferential directions of the positioning structure;

[0020] Establish the spring element between the nodes of the first surface mesh and the nodes of the second surface mesh that correspond one-to-one.

[0021] In some embodiments, obtaining the axial stiffness of the spring element includes:

[0022] Determine the initial axial stiffness of the spring element according to the empirical value.

[0023] In some embodiments, calculating the first calculated main frequency and the second calculated main frequency using the finite element model of the battery swapping module framework and the axial stiffness of the spring element includes:

[0024] Calculate the mode of the battery swapping module framework within a preset frequency range;

[0025] According to the mode result, determine a certain order of frequency corresponding to the maximum effective mass participating in vibration in the vibration mode of the battery swapping module framework in the same direction as the direction where the first test main frequency is located as the first calculated main frequency, and determine a certain order of frequency corresponding to the maximum effective mass participating in vibration in the vibration mode of the battery swapping module framework in the same direction as the direction where the second test main frequency is located as the second calculated main frequency.

[0026] In some embodiments, calculating the first calculated main frequency and the second calculated main frequency using the finite element model of the battery swapping module framework and the axial stiffness of the spring element includes:

[0027] Taking the combined value of the axial stiffnesses of the multiple spring units as a variable, and taking the first calculated main frequency being within a first set range and the second calculated main frequency being within a second set range as the objective function, continuously optimize and iterate the combined values of the axial stiffnesses of the multiple spring units so that the first calculated main frequency is within the first set range and the second calculated main frequency is within the second set range.

[0028] In some embodiments, the benchmarking method includes:

[0029] In the case where the first calculated main frequency is not within the first set range and / or the second calculated main frequency is not within the second set range, adjust the axial stiffness of the spring unit and return to the step of calculating the first calculated main frequency and the second calculated main frequency.

[0030] An apparatus for benchmarking the stiffness of the spring unit between pin holes applied to a swapping module frame according to an embodiment of the present invention includes:

[0031] A processor, and;

[0032] A memory, the memory stores a computer program, and the computer program, when executed by the processor, implements the steps of the benchmarking method for the stiffness of the spring unit between pin holes applied to the swapping module frame according to any of the above embodiments.

[0033] A swapping device according to an embodiment of the present invention includes a swapping module frame, and the swapping module frame is a swapping module frame obtained by performing random vibration simulation using the axial stiffness of the spring unit, and the axial stiffness of the spring unit is determined by the benchmarking method for the stiffness of the spring unit between pin holes applied to the swapping module frame according to any of the above embodiments.

[0034] An embodiment of the present invention provides a computer-readable storage medium, on which a computer program is stored, and the computer program, when executed by a processor, implements the steps of the benchmarking method for the stiffness of the spring unit between pin holes applied to the swapping module frame according to any of the above embodiments.

[0035] In the above benchmarking device, swapping device, and computer-readable storage medium, the spring unit connects the nodes of the first surface mesh of the positioning pin mating surface and the nodes of the second surface mesh of the positioning hole mating surface, establishing the relative movement relationship between the positioning pin and the positioning hole in the axial and radial directions of the positioning structure. By determining the final axial stiffness of the spring unit, the relative movement between the positioning pin and the positioning hole in the axial and radial directions of the positioning structure can be accurately simulated, and thus the mode and / or random vibration simulation of the swapping module frame can be accurately simulated.

[0036] The additional aspects and advantages of the present invention will be partially given in the following description, partially become apparent from the following description, or be understood through the practice of the present invention. Brief Description of the Drawings

[0037] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the description of the embodiments in conjunction with the following drawings, wherein:

[0038] Figure 1 is a schematic flow chart of a method for benchmarking the stiffness of a spring unit between pin holes applied to a battery swapping module frame according to an embodiment of the present invention;

[0039] Figure 2 is a schematic structural diagram of a battery swapping module frame according to an embodiment of the present invention;

[0040] Figure 3 is a schematic diagram of the cooperation between a positioning pin and a positioning hole according to an embodiment of the present invention;

[0041] Figure 4 is a perspective view of a positioning pin according to an embodiment of the present invention;

[0042] Figure 5 is a perspective view of a positioning hole according to an embodiment of the present invention;

[0043] Figure 6 is a schematic diagram of the mesh division of a positioning pin and a positioning hole according to an embodiment of the present invention;

[0044] Figure 7 is Figure 6 a schematic cross-sectional view of line B-B in;

[0045] Figure 8 is Figure 6 an enlarged schematic view of part C in;

[0046] Figure 9 is a schematic diagram of the surface mesh node distribution of a positioning pin and a positioning hole according to an embodiment of the present invention;

[0047] Figure 10 is Figure 9 an enlarged schematic view of part D in;

[0048] Figure 11 is a schematic diagram of the circumferential position of a positioning pin and a positioning hole according to an embodiment of the present invention. Detailed Embodiments

[0049] The following describes in detail the embodiments of the present invention. Examples of the embodiments are shown in the drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary only for explaining the present invention and should not be construed as limiting the present invention.

[0050] In the description of the present invention, "a plurality of" means two or more, unless otherwise specifically defined.

[0051] In the description of the present invention, it should be noted that, unless otherwise clearly specified and defined, the terms "mounted", "connected", and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection. It can be a mechanical connection or an electrical connection. It can be directly connected or indirectly connected through an intermediate medium. It can be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0052] In the present invention, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween.

[0053] The present disclosure provides many different embodiments or examples for implementing different structures of the present invention. To simplify the disclosure of the present invention, the components and settings of specific examples are described herein. Of course, they are only examples and are not intended to limit the present invention. In addition, the present invention may repeat reference numerals and / or reference letters in different examples. This repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides examples of various specific processes and materials, but those of ordinary skill in the art may be aware of the application of other processes and / or the use of other materials.

[0054] Please refer Figures 1 to 10 , an embodiment of the present invention provides a method for benchmarking the stiffness of the spring unit 5 between pin holes applied to a battery swapping module frame. The battery swapping module frame includes an upper frame 1, a bottom bracket 2, and a positioning structure. The positioning structure includes a positioning pin 3 and a positioning hole 4. The positioning pin 3 is connected to the bottom bracket 2, and the positioning hole 4 is connected to the upper frame 1. The upper frame 1 and the bottom bracket 2 achieve positioning cooperation in the axial direction of the positioning structure through the positioning pin 3 and the positioning hole 4.

[0055] The benchmarking method includes:

[0056] Step 101, perform a sweep frequency test on the battery swapping module frame to obtain the first test main frequency and the second test main frequency of the battery swapping module frame. The directions where the first test main frequency and the second test main frequency are located are different directions in the radial direction of the positioning structure;

[0057] Step 103: Build a finite element model of the battery swapping module framework. Among them, the finite element model of the positioning pin 3 includes the first surface mesh 331 of the positioning pin mating surface 33, and the finite element model of the positioning hole 4 includes the second surface mesh 411 of the positioning hole mating surface 41. A spring element 5 is established between the nodes of the first surface mesh 331 and the nodes of the second surface mesh 411;

[0058] Step 105: Obtain the axial stiffness of the spring element 5;

[0059] Step 107: Calculate the first calculation main frequency and the second calculation main frequency by using the finite element model of the battery swapping module framework and the axial stiffness of the spring element 5. The direction where the first calculation main frequency is located is the same as the direction where the first test main frequency is located, and the direction where the second calculation main frequency is located is the same as the direction where the second test main frequency is located;

[0060] Step 109: When the first calculation main frequency is within the first set range and the second calculation main frequency is within the second set range, determine the axial stiffness of the spring element 5 as the axial stiffness of the spring element 5 used in the modal and / or random vibration simulation. The first set range is determined according to the first test main frequency, and the second set range is determined according to the second test main frequency.

[0061] In the above alignment method, the spring element 5 connects the nodes of the first surface mesh 331 of the positioning pin mating surface 33 and the nodes of the second surface mesh 411 of the positioning hole mating surface 41, and builds the relative movement relationship between the positioning pin 3 and the positioning hole 4 in the axial and radial directions of the positioning structure. By determining the final axial stiffness of the spring element 5, the relative movement between the positioning pin 3 and the positioning hole 4 in the axial and radial directions of the positioning structure can be accurately simulated, and then the modal and / or random vibration simulation of the battery swapping module framework can be accurately simulated.

[0062] Specifically, the battery swapping module framework is fixed on the mobile battery swapping vehicle through the bottom bracket 2, and the upper framework 1 can be used to place the battery pack. The battery pack can be installed on the vehicle by the robot on the mobile battery swapping vehicle.

[0063] The positioning pin 3 can be fixed on the bottom bracket 2. Please refer to Figure 4 , in one embodiment, the positioning pin 3 includes a pin body and a base 35. The pin body is arranged on the base 35, and the positioning pin 3 is connected to the bottom bracket 2 through the base 35. The base 35 can be connected to the bottom bracket 2 by welding.

[0064] From the direction close to the base 35, the pin body successively includes a positioning pin round table surface 31, a first non-mating surface 32, a positioning pin mating surface 33 and a second non-mating surface 34. The positioning pin round table surface 31 can facilitate the insertion of the pin body into the positioning hole 4. In Figure 4In the illustrated embodiment, the first non-mating surface 32, the dowel pin mating surface 33, and the second non-mating surface 34 are all cylindrical surfaces. The dowel pin mating surface 33 is located between the first non-mating surface 32 and the second non-mating surface 34.

[0065] Please refer Figure 5 , the positioning hole 4 is formed in the positioning plate 42, and the positioning plate 42 can be connected to the upper frame 1 by, for example, welding. The inner wall of the positioning hole 4 has a positioning hole mating surface 41. In Figure 5 the illustrated embodiment, the positioning hole mating surface 41 is a cylindrical mating surface. In other embodiments, the first non-mating surface 32, the dowel pin mating surface 33, the second non-mating surface 34, and the positioning hole mating surface 41 can be surfaces of other shapes, and are not limited to cylindrical surfaces, as long as the shapes of the first non-mating surface 32, the dowel pin mating surface 33, and the second non-mating surface 34 match the shape of the positioning hole mating surface 41.

[0066] In one embodiment, the direction of the first test main frequency is Figure 2 the X direction in Figure 2 , and the direction of the second test main frequency is Figure 2 the Y direction in

[0067] That is, the first test main frequency can be the X-direction main frequency, the second test main frequency can be the Y-direction main frequency, and the axis of the positioning structure is parallel to

[0068] the Z direction in

[0069] That is to say, the upper frame 1 and the bottom bracket 2 are positioned and mated in the Z direction through the dowel pin 3 and the positioning hole 4.

[0067] The radial direction of the positioning structure is parallel to the XY plane. The axial direction of the positioning structure is the axial direction of the dowel pin 3 and also the axial direction of the positioning hole 4. The radial direction of the positioning structure is the radial direction of the dowel pin 3 and also the radial direction of the positioning hole 4. The axial direction of the spring unit 5 can be the radial direction of the positioning structure. The axial stiffness of the spring unit 5 will affect the calculated main frequency. For example, if the spring stiffness in a certain direction increases, the main frequency in that direction will increase, and if the spring stiffness in a certain direction decreases, the main frequency in that direction will decrease.

[0068] In one embodiment, the frame of the battery swapping module can be welded from a steel pipe structure. In step 103, the steel pipe structure is simulated using shell elements, and the steel pipes are connected using welding elements. A bonded connection is used between the upper frame 1 and the bottom bracket 2 at the positions where there is a pin stop mechanism. The frame of the battery swapping module can be divided into grids, and the grid elements of the dowel pin 3 are connected to the grid elements of the bottom bracket 2 using welding elements, and the grid elements of the positioning hole 4 are connected to the grid elements of the upper frame 1 using welding elements.

[0069] It should be noted that the finite element model of the battery swapping module frame is not the focus of the present invention. The structures and materials of the battery swapping module frame listed in the present invention are only exemplary structures and materials, and the finite element modeling method of the battery swapping module frame is also only a commonly used modeling method. It does not exclude using solid elements for modeling of the steel pipe structure, nor does it exclude using an aluminum alloy frame or a frame of other materials for the battery swapping module frame. The present invention is applicable to the finite element modeling of all battery swapping module frames adopting pin hole structures.

[0070] Please refer Figure 9 and Figure 10 , a spring element 5 can connect a node of the first surface mesh 331 and a node of the second surface mesh 411. In one embodiment, the number and positions of the nodes of the first surface mesh 331 and the number and positions of the nodes of the second surface mesh 411 are in one-to-one correspondence.

[0071] In one embodiment, the first set range can be (0.9×f x , 1.1×f x ), and the second set range can be (0.9×f y , 1.1×f y ), where f x represents the first test main frequency, and f y represents the second test main frequency. That is, when the calculated main frequency and the test main frequency need to satisfy the following relational expression (1), the axial stiffness of the spring element 5 can be determined as the final axial stiffness of the spring element 5, and the random vibration simulation of the battery swapping module frame can be carried out by using the axial stiffness of the spring element 5, or the modal and random vibration simulations of other frames can be carried out, or the modal or random vibration simulations of other frames can be carried out, etc.

[0072]

[0073] Among them, F X represents the first calculated main frequency, and F y represents the second calculated main frequency. It can be understood that in other embodiments, the first set range can also be other set ranges determined according to the first test main frequency, and the second set range can also be other set ranges determined according to the second test main frequency, which are not specifically limited herein.

[0074] In one embodiment, the positioning structure radially includes the X direction and the Y direction, and step 101 includes:

[0075] Fix the battery swapping module frame on the horizontal vibration table through a tooling, install a control sensor on the tooling, and install a monitoring sensor on the battery swapping module frame;

[0076] Perform a sweep frequency test in the X direction and the Y direction using a horizontal vibration table, and obtain a frequency-acceleration test curve by controlling the test data output by the sensors and monitoring the sensors.

[0077] Obtain the first test main frequency and the second test main frequency according to the test curve. The direction where the first test main frequency is located is the X direction, and the direction where the second test main frequency is located is the Y direction.

[0078] In this way, the first test main frequency and the second test main frequency can be obtained.

[0079] Specifically, fix the battery swapping module frame to the horizontal vibration table through a fixture. When the sensors are installed in place, the excitation acceleration of the horizontal vibration table can be set to 0.2g, and a sine sweep frequency is adopted. The sweep frequency range is set to 5 Hz to 200 Hz, and the logarithmic sweep frequency method is used with a sweep frequency of 1 oct / min. The control sensor and the monitoring sensor can be acceleration sensors. The control sensor is fixed to the fixture, and the monitoring sensor is fixed near the center position of the middle Z-direction vertical beam of the battery swapping module frame, such as Figure 2 the position of the solid coil E shown.

[0080] Perform a sweep frequency test in the X direction and the Y direction respectively, and obtain a frequency-acceleration test curve by controlling the test data output by the sensors and monitoring the sensors. The peak value of the frequency-acceleration curve can be observed. Generally, the frequency corresponding to the peak value where the first monitored acceleration is greater than twice the control acceleration is used as the main frequency in this direction. The monitored acceleration can be obtained from the monitoring sensor, and the control acceleration can be obtained from the control sensor.

[0081] It can be understood that the above parameters of the sweep frequency test method are recommended parameters and test methods, and the present invention is not limited to the specific magnitudes of the above parameters.

[0082] In one embodiment, please refer to Figures 3 to 5 , the positioning pin 3 includes a first non-mating surface 32, a positioning pin mating surface 33, and a second non-mating surface 34. The positioning pin mating surface 33 is located between the first non-mating surface 32 and the second non-mating surface 34. The positioning hole 4 includes a positioning hole mating surface 41 that is in clearance fit with the positioning pin mating surface 33;

[0083] Step 103 includes:

[0084] Divide the positioning pin 3 and the positioning hole 4 into polyhedral meshes to obtain a first surface mesh 331 and a second surface mesh 411. The number and position of the nodes of the first surface mesh 331 correspond one-to-one with the number and position of the nodes of the second surface mesh 411 in the axial and circumferential directions of the positioning structure;

[0085] Establish a spring element 5 between the nodes of the first surface mesh 331 and the nodes of the second surface mesh 411 that correspond one-to-one.

[0086] In this way, on the basis of building a finite element model of the framework of the battery swapping module, the spring element 5 can be further established.

[0087] Specifically, in one embodiment, please refer to Figures 6 to 10 , the polyhedron mesh can be a hexahedron mesh, that is, the positioning pin 3 and the positioning hole 4 are divided according to the hexahedron mesh to obtain the first surface mesh 331 of the positioning pin mating surface 33 and the second surface mesh 411 of the positioning hole mating surface 41. The number and position of the nodes of the first surface mesh 331 correspond one by one to the number and position of the nodes of the second surface mesh 411 in the axial and circumferential directions of the positioning structure, so that a spring element 5 can be established between the nodes of the first surface mesh 331 and the nodes of the second surface mesh 411 in one-to-one correspondence. That is to say, a spring element 5 can connect a node of the first surface mesh 331 and a node of the second surface mesh 411, and the positions of the node of the first surface mesh 331 and the node of the second surface mesh 411 are corresponding.

[0088] For example, the first surface mesh 331 of the positioning pin mating surface 33 arranges n nodes in the circumferential direction and m nodes in the axial direction; they are sequentially denoted as PNode nm .

[0089] The second surface mesh 411 of the positioning hole mating surface 41 arranges n nodes in the circumferential direction and m nodes in the axial direction; they are sequentially denoted as HNode nm . The spring element 5 is established between PNode nm and HNode nm at the same circumferential and axial positions, and they are sequentially denoted as Spring nm .

[0090] In one embodiment, step 105 includes:

[0091] Determine the initial axial stiffness of the spring element 5 according to the empirical value.

[0092] In this way, the method for determining the initial axial stiffness of the spring element 5 is simple and feasible.

[0093] Specifically, the initial axial stiffness of the spring element 5 can be determined according to the empirical value, and the initial axial stiffness of the spring element 5 can be the axial stiffness of the spring element 5 used in the first calculation of the first calculation main frequency and the second calculation main frequency.

[0094] In one embodiment, the total number of spring elements 5 is n*m. Assuming that the stiffness of the m spring elements 5 at each circumferential position is the same, the spring stiffness of the n groups of spring elements 5 along the circumference of the positioning pin 3 is sequentially positioned as k 1 , k 2, k 3 ,......, k n . As Figure 11 shown at the oval frame line, "each circumferential position" may refer to positions with the same radial angle but in a row axially.

[0095] In one embodiment, step 107 includes:

[0096] Calculate the mode of the battery swapping module frame within a preset frequency range;

[0097] According to the mode result, determine a certain order frequency corresponding to the maximum effective mass participating in vibration in the vibration mode of the battery swapping module frame in the same direction as the first test main frequency as the first calculated main frequency, and determine a certain order frequency corresponding to the maximum effective mass participating in vibration in the vibration mode of the battery swapping module frame in the same direction as the second test main frequency as the second calculated main frequency.

[0098] In this way, the first calculated main frequency and the second calculated main frequency can be obtained.

[0099] In one embodiment, the first calculated main frequency is the X-direction calculated main frequency, the second calculated main frequency is the Y-direction calculated main frequency, and the preset frequency range can be 5 Hz to 200 Hz. The finite element model of the battery swapping module frame built above can be used. In the finite element analysis software, constrain the connection points (usually bolt holes) between the battery swapping module frame and the tooling, calculate the modes between 5 Hz and 200 Hz, and obtain the mode result file. By analyzing the mode result file, if the effective mass participating in vibration in the vibration mode of the battery swapping module frame at a certain order frequency is the largest, then this order frequency is the main frequency in this direction, and thus the X and Y direction calculated main frequencies F X , F Y .

[0100] In some embodiments, step 107 includes:

[0101] Taking the combined value of the axial stiffnesses of multiple spring units 5 as a variable and taking the first calculated main frequency being within the first set range and the second calculated main frequency being within the second set range as the objective function, continuously optimize and iterate the combined value of the axial stiffnesses of multiple spring units 5 so that the first calculated main frequency is within the first set range and the second calculated main frequency is within the second set range.

[0102] In this way, automatic optimization can be achieved through programming.

[0103] Specifically, a programming language can be used, with the axial stiffnesses k 1 , k 2 , k 3 ,......, k nThe combined values are variables. Taking the above formula (1) as the objective function, combined with the finite element calculation method, genetic algorithms, DOE methods, etc. are used to continuously obtain k 1 、k 2 、k 3 ,......,k n 's combined values, and input them into the finite element program to calculate the mode of the battery swapping module frame, continuously optimize and iterate, and finally obtain k 1 、k 2 、k 3 ,......,k n combined values.

[0104] In some embodiments, the benchmarking method includes:

[0105] In the case where the first calculated main frequency is not within the first set range and / or the second calculated main frequency is not within the second set range, adjust the axial stiffness of the spring unit 5 and return to the step of calculating the first calculated main frequency and the second calculated main frequency.

[0106] In this way, the first calculated main frequency and the second calculated main frequency can be re-obtained.

[0107] Specifically, in one embodiment, when the calculated main frequency and the test main frequency do not meet one or both of the conditions in the above formula (1), adjust the axial wind stiffness of the spring unit 5 and return to the step of calculating the first calculated main frequency and the second calculated main frequency, that is, re-calculate the first calculated main frequency and the second calculated main frequency using the adjusted axial stiffness of the spring unit 5.

[0108] Adjust the axial stiffness of the spring unit 5, that is, adjust k 1 、k 2 、k 3 ,......,k n 's values, and the adjustment method can adopt the trial method.

[0109] An apparatus for benchmarking the stiffness of the spring unit 5 between pin holes applied to the battery swapping module frame according to an embodiment of the present invention includes a processor and a memory. The memory stores a computer program, and when the computer program is executed by the processor, it implements the steps of the benchmarking method for the stiffness of the spring unit 5 between pin holes applied to the battery swapping module frame in any of the above embodiments.

[0110] A battery swapping device according to an embodiment of the present invention includes a battery swapping module frame, which is a battery swapping module frame obtained by performing random vibration simulation using the axial stiffness of the spring unit 5, and the axial stiffness of the spring unit 5 is determined by the benchmarking method for the stiffness of the spring unit 5 between pin holes applied to the battery swapping module frame in any of the above embodiments.

[0111] An embodiment of the present invention provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the method for calibrating the stiffness of the spring unit 5 between the pin holes applied to the swapping module frame in any of the above embodiments are implemented.

[0112] It should be noted that the above explanations of the embodiments and beneficial effects of the method for calibrating the stiffness of the spring unit 5 between the pin holes applied to the swapping module frame are also applicable to the device for calibrating the stiffness of the spring unit 5 between the pin holes applied to the swapping module frame, the swapping device, and the computer-readable storage medium. To avoid redundancy, no detailed expansion will be made here.

[0113] In one embodiment, when the computer program is executed by a processor, the method for calibrating the stiffness of the spring unit 5 between the pin holes applied to the swapping module frame includes:

[0114] Step 101, perform a frequency sweep test on the swapping module frame to obtain the first test main frequency and the second test main frequency of the swapping module frame. The directions where the first test main frequency and the second test main frequency are located are different directions in the radial direction of the positioning structure;

[0115] Step 103, build a finite element model of the swapping module frame. Among them, the finite element model of the positioning pin 3 includes the first surface mesh 331 of the positioning pin mating surface 33, and the finite element model of the positioning hole 4 includes the second surface mesh 411 of the positioning hole mating surface 41. A spring unit 5 is established between the nodes of the first surface mesh 331 and the nodes of the second surface mesh 411;

[0116] Step 105, obtain the axial stiffness of the spring unit 5;

[0117] Step 107, calculate the first calculated main frequency and the second calculated main frequency by using the finite element model of the swapping module frame and the axial stiffness of the spring unit 5. The direction where the first calculated main frequency is located is the same as the direction where the first test main frequency is located, and the direction where the second calculated main frequency is located is the same as the direction where the second test main frequency is located;

[0118] Step 109, when the first calculated main frequency is within the first set range and the second calculated main frequency is within the second set range, determine the axial stiffness of the spring unit 5 as the axial stiffness of the spring unit 5 used in modal and / or random vibration simulation. The first set range is determined according to the first test main frequency, and the second set range is determined according to the second test main frequency.

[0119] In the above alignment device, battery swapping device, and computer-readable storage medium, the spring unit 5 connects the nodes of the first surface grid 331 of the positioning pin mating surface 33 and the nodes of the second surface grid 411 of the positioning hole mating surface 41, establishing the relative movement relationship between the positioning pin 3 and the positioning hole 4 in the axial and radial directions of the positioning structure. By determining the final axial stiffness of the spring unit 5, the relative movement of the positioning pin 3 and the positioning hole 4 in the axial and radial directions of the positioning structure can be accurately simulated, and thus the mode and / or random vibration simulation of the battery swapping module frame can be accurately simulated.

[0120] It can be understood that a computer program includes computer program code. The computer program code can be in the form of source code, object code, executable file, or some intermediate form, etc. The computer-readable storage medium can include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disc, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), and software distribution medium, etc. The processor can be a central processing unit, or other general-purpose processors, digital signal processors (DSP, Digital Signal Processor), application specific integrated circuits (ASIC, Application Specific Integrated Circuit), field-programmable gate arrays (FPGA, Field-Programmable Gate Array), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0121] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0122] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and purposes of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A method for benchmarking the stiffness of the spring unit between pin holes applied to the frame of a battery swapping module, characterized in that, the frame of the battery swapping module includes an upper frame, a bottom bracket and a positioning structure, the positioning structure includes a positioning pin and a positioning hole, the positioning pin is connected to the bottom bracket, the positioning hole is connected to the upper frame, and the upper frame and the bottom bracket are positioned and matched axially in the positioning structure through the positioning pin and the positioning hole; the benchmarking method includes: performing a sweep frequency test on the frame of the battery swapping module to obtain a first test main frequency and a second test main frequency of the frame of the battery swapping module, and the directions where the first test main frequency and the second test main frequency are located are different directions in the radial direction of the positioning structure; building a finite element model of the frame of the battery swapping module, wherein the finite element model of the positioning pin includes a first surface mesh of the positioning pin mating surface, the finite element model of the positioning hole includes a second surface mesh of the positioning hole mating surface, and a spring unit is established between the nodes of the first surface mesh and the nodes of the second surface mesh; obtaining the axial stiffness of the spring unit; calculating a first calculated main frequency and a second calculated main frequency by using the finite element model of the frame of the battery swapping module and the axial stiffness of the spring unit, the direction where the first calculated main frequency is located is the same as the direction where the first test main frequency is located, and the direction where the second calculated main frequency is located is the same as the direction where the second test main frequency is located; when the first calculated main frequency is within a first set range and the second calculated main frequency is within a second set range, determining the axial stiffness of the spring unit as the axial stiffness of the spring unit used in modal and / or random vibration simulation, the first set range is determined according to the first test main frequency, and the second set range is determined according to the second test main frequency.

2. The benchmarking method according to claim 1, characterized in that, the radial direction of the positioning structure includes the X direction and the Y direction, and performing a sweep frequency test on the frame of the battery swapping module to obtain a first test main frequency and a second test main frequency of the frame of the battery swapping module includes: fixing the frame of the battery swapping module on a horizontal vibration table through a tooling, installing a control sensor on the tooling, and installing a monitoring sensor on the frame of the battery swapping module; performing a sweep frequency test in each of the X direction and the Y direction by using the horizontal vibration table, and obtaining a frequency-acceleration test curve through the test data output by the control sensor and the monitoring sensor; obtaining the first test main frequency and the second test main frequency according to the test curve, the direction where the first test main frequency is located is the X direction, and the direction where the second test main frequency is located is the Y direction.

3. The benchmarking method according to claim 1, characterized in that, the positioning pin includes a first non-mating surface, a positioning pin mating surface and a second non-mating surface, the positioning pin mating surface is located between the first non-mating surface and the second non-mating surface, and the positioning hole includes a positioning hole mating surface that is in clearance fit with the positioning pin mating surface; building the finite element model of the frame of the battery swapping module includes: The positioning pin and the positioning hole are divided according to a polyhedron grid to obtain the first surface grid and the second surface grid. The number and position of the nodes of the first surface grid correspond one-to-one with the number and position of the nodes of the second surface grid in the axial and circumferential directions of the positioning structure; A spring element is established between the nodes of the first surface grid and the nodes of the second surface grid that correspond one-to-one.

4. The alignment method according to claim 1, wherein, obtaining the axial stiffness of the spring element includes: Determining the initial axial stiffness of the spring element according to an empirical value.

5. The alignment method according to claim 1, wherein, calculating the first calculated main frequency and the second calculated main frequency by using the finite element model of the battery swapping module frame and the axial stiffness of the spring element includes: Calculating the mode of the battery swapping module frame within a preset frequency range; According to the mode result, a certain order frequency corresponding to the maximum effective mass participating in vibration in the vibration mode of the battery swapping module frame in the same direction as the direction where the first test main frequency is located is determined as the first calculated main frequency, and a certain order frequency corresponding to the maximum effective mass participating in vibration in the vibration mode of the battery swapping module frame in the same direction as the direction where the second test main frequency is located is determined as the second calculated main frequency.

6. The alignment method according to claim 1, wherein, calculating the first calculated main frequency and the second calculated main frequency by using the finite element model of the battery swapping module frame and the axial stiffness of the spring element includes: Taking the combined value of the axial stiffnesses of multiple spring elements as a variable, and taking the first calculated main frequency being within a first set range and the second calculated main frequency being within a second set range as the objective function, continuously optimizing and iterating the combined values of the axial stiffnesses of multiple spring elements so that the first calculated main frequency is within the first set range and the second calculated main frequency is within the second set range.

7. The alignment method according to claim 1, wherein, the alignment method includes: In the case where the first calculated main frequency is not within the first set range and / or the second calculated main frequency is not within the second set range, adjusting the axial stiffness of the spring element and returning to the step of calculating the first calculated main frequency and the second calculated main frequency.

8. An alignment device for the stiffness of the spring element between the pin holes of a battery swapping module frame, wherein, it includes: a processor, and; a memory, the memory stores a computer program, and the computer program realizes the steps of the alignment method for the stiffness of the spring element between the pin holes of the battery swapping module frame according to any one of claims 1-7 when being executed by the processor.

9. A battery swapping device, wherein, it includes a battery swapping module frame, and the battery swapping module frame is a battery swapping module frame obtained by performing random vibration simulation by using the axial stiffness of a spring element, and the axial stiffness of the spring element is determined by the alignment method for the stiffness of the spring element between the pin holes of the battery swapping module frame according to any one of claims 1-7.

10. A computer-readable storage medium, on which a computer program is stored, wherein, When the computer program is executed by a processor, it implements the steps of the method for benchmarking the stiffness of the spring unit between the pin holes applied to the frame of the battery swapping module according to any one of claims 1-7.

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