Expansion force testing tool and expansion force testing equipment
By introducing a flexible contact design between the protective body and the clamping body in the battery cell expansion force testing fixture, the problem of damage to battery cells due to uneven force during testing is solved, achieving higher testing reliability and accuracy.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-14
- Publication Date
- 2026-04-03
AI Technical Summary
In battery cell expansion force testing, battery cells are easily damaged due to uneven stress, leading to reduced reliability.
An expansion force testing fixture was designed, comprising a base, a clamping body, and a protective body. The clamping body contacts the battery cell through the protective body, and the flexibility of the protective body provides elastic support to reduce the risk of structural damage. The clamping body is adjustable to accommodate battery cells of different specifications, and the clamping force is precisely controlled by a pressure sensor.
It improves the reliability and accuracy of battery cells in expansion force testing, reduces the probability of damage to battery cells during testing, and has wider applicability.
Smart Images
Figure CN224081101U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of battery testing technology, and in particular to an expansion force testing fixture and expansion force testing equipment. Background Technology
[0002] In a battery, as a single cell is charged and discharged repeatedly, its volume expands proportionally, creating an expansion force between adjacent cells. The magnitude of this expansion force is crucial to the battery's structural and safety performance. Therefore, during the research and manufacturing of battery modules, it is necessary to test the battery's expansion force to assess its performance.
[0003] In the battery cell expansion force test of related technologies, the large surface of the battery cell is usually placed between two clamps, and the battery cell is squeezed by the two clamps. The expansion force is tested by collecting the force on the clamps with the help of sensors.
[0004] However, individual battery cells are prone to structural damage during testing due to uneven stress on a large surface area, which reduces the reliability of the individual battery cells. Utility Model Content
[0005] Therefore, it is necessary to provide a more reliable expansion force testing fixture and equipment to address the problem that battery cells are easily damaged during expansion force testing.
[0006] In a first aspect, embodiments of this application provide an expansion force testing fixture, which includes a base, a clamping body, and a protective body. The base includes a first surface for supporting a single battery cell. The clamping body is disposed on the base and configured to clamp and position the single battery cell in a direction parallel to the first surface. The protective body is connected to the clamping body and is used to contact the single battery cell.
[0007] In the technical solution of this application embodiment, by setting a protective body connected to the clamping body, the clamping body contacts the battery cell through the protective body, thereby positioning the battery cell. The flexibility of the protective body itself can provide elastic support for the battery cell in the direction parallel to the first plane, reducing the risk of structural damage to the battery cell when subjected to uneven stress, thereby improving the reliability of the expansion force testing fixture.
[0008] In some embodiments, the clamping body includes a first clamping member and a second clamping member, which are arranged opposite each other along a straight line, and a protective body is disposed on at least one of the first clamping member and the second clamping member. In this way, by using the first clamping member and the second clamping member to clamp the opposing walls of the battery cell, the positioning effect of the clamping body on the battery cell can be improved, further enhancing the reliability of the expansion force testing fixture.
[0009] In some embodiments, at least one of the first and second clamping members is position-adjustable along a direction in which the first and second clamping members are positioned opposite each other. This design enables the clamping body to be adjustable, allowing it to be adjusted according to the specifications and dimensions of the battery cell, thus improving its applicability.
[0010] In some embodiments, the number of clamping bodies is at least two, wherein the clamping directions of the two clamping bodies intersect. By using at least two clamping bodies to clamp the battery cell together, the clamping and positioning effect of the battery cell can be further improved, and more of the battery cell's walls can be protected.
[0011] In some embodiments, one of the first clamping member and the second clamping member is a fixed wall fixedly connected to the substrate, and the other is a movable wall that can move relative to the substrate in a direction toward or away from the fixed wall. This design can provide pre-positioning for the battery cell using two fixed walls, that is, the approximate position of the battery cell can be determined by the two fixed walls, and then the battery cell can be clamped and positioned by adjusting the two movable walls respectively, thereby improving the accuracy of battery cell positioning.
[0012] In some embodiments, two clamping bodies are used, with their two fixed walls connected and forming a pre-positioning area with the base. This pre-positioning area is used to place the battery cell. This design utilizes two fixed walls to form the pre-positioning area, and the connection between the two fixed walls ensures that the battery cell is positioned consistently each time, which helps improve the uniformity of expansion force testing for different battery cells.
[0013] In some embodiments, the expansion force testing fixture further includes a driving assembly, which includes a fixed base and a driving member. The fixed base is fixedly connected to the base, and the driving member is disposed on the fixed base. The output end of the driving member cooperates with a first clamping member and / or a second clamping member. The cooperation between the output end of the driving member and the first clamping member and / or the second clamping member allows the driving member to move, enabling the expansion force testing fixture to be adjustable. This allows for adjustments based on the specifications and dimensions of the battery cell, resulting in better applicability.
[0014] In some embodiments, the mounting base and drive element are configured as a lead screw assembly; or, the mounting base and drive element are configured as a cylinder assembly. This design facilitates precise control of the clamping force applied to the clamping body.
[0015] In some embodiments, the expansion force testing fixture further includes a pressure sensor disposed on the protective body and used to transmit the pressure value borne by the protective body. By disposing of the pressure sensor on the protective body and using the pressure sensor to transmit the pressure value borne by the protective body, i.e., using the pressure sensor to monitor the clamping force applied by the clamping body to the battery cell, it is beneficial to more accurately control the clamping force of the clamping body.
[0016] In some embodiments, the pressure sensor is disposed between the protective body and the clamping body. This design reduces the difficulty of disassembling and assembling the pressure sensor, facilitating maintenance or replacement during use.
[0017] In some embodiments, the first surface is used to support the large surface of the battery cell. When the press performs an expansion force test on the battery cell, pressure is applied to the large surface of the battery cell to perform the expansion force test. Since the large surface of the battery cell is more prone to deformation due to expansion force, this design can further improve the testing accuracy of the expansion force testing fixture.
[0018] In some embodiments, the clamping body and the protective body are glued together. This improves the structural consistency between the clamping body and the protective body, reduces the possibility of the protective body becoming loose or displaced during the operation of the expansion force testing fixture, and further enhances the reliability of the expansion force testing fixture.
[0019] In some embodiments, the protective body is a polyurethane component, a silicone rubber component, an epoxy resin component, a polyimide component, a polytetrafluoroethylene component, a polyvinyl chloride component, or a polyamide component. This allows the protective body to achieve suitable hardness and elasticity, preventing excessive deformation when the battery cell is clamped by the clamping body, thus providing good clamping and positioning. Simultaneously, during expansion force testing, it provides elastic support for the deformation of the battery cell, reducing the possibility of damage to the battery cell during the expansion force test.
[0020] In some embodiments, the hardness of the protective body is not less than Shore hardness D60 and not greater than Shore hardness D70; and / or, the tensile strength of the protective body is not less than 44 MPa and not greater than 46 MPa; and / or, the tear strength of the protective body is not less than 155 MPa and not greater than 163 MPa; and / or, the flexural strength of the protective body is not less than 18 MPa and not greater than 20 MPa; and / or, the impact strength of the protective body is not less than 109 MPa and not greater than 114 MPa. By controlling the hardness and elasticity of the protective body within a suitable range, the protective body can provide good protection for the battery cells while reducing its own damage during testing.
[0021] Secondly, embodiments of this application also provide an expansion force testing device, which includes the expansion force testing fixture provided in any of the foregoing embodiments.
[0022] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description
[0023] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0024] Figure 1 This is a three-dimensional structural schematic diagram of the expansion force testing fixture in one embodiment of this application;
[0025] Figure 2 This is a top view of the expansion force testing fixture in one embodiment of this application;
[0026] Figure 3 for Figure 2 Enlarged view of part A of the expansion force testing fixture shown;
[0027] Figure 4 This is a schematic diagram of the planar structure of the expansion force testing device in one embodiment of this application.
[0028] Explanation of reference numerals in the attached drawings: 100, Expansion force testing fixture; 10, Base; 11, First surface; 20, Clamping body; 21, First clamping element; 22, Second clamping element; 30, Protective body; 40, Drive assembly; 41, Fixing base; 42, Drive element; 50, Pressure sensor; 101, Pre-positioning area; 102, Guide groove;
[0029] 1000, Expansion force testing equipment; 200, Battery cell; 300, Press. Detailed Implementation
[0030] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.
[0031] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.
[0032] Furthermore, where the term "and / or" appears, "and / or" merely describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship. Where the terms "first" and "second" appear, these terms are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" can explicitly or implicitly include at least one of those features. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0033] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0034] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.
[0035] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.
[0036] In a battery, as the battery cells are charged and discharged in cycles, gas is generated inside the battery cell casing due to structural changes in the electrode active materials and side reactions of the electrolyte. Some battery cells will expand to varying degrees after use, resulting in expansion forces between adjacent battery cells.
[0037] The magnitude of expansion force is crucial to the structure and safety performance of battery design. Therefore, during the research and development and manufacturing process of battery modules, it is necessary to test the expansion force of the battery to evaluate the safety, performance, and lifespan of individual battery cells.
[0038] In the battery cell expansion force test of related technologies, the large surface of the battery cell is usually placed between two clamps, and the battery cell is squeezed by the two clamps. The expansion force is tested by collecting the force on the clamps with the help of sensors.
[0039] However, during the expansion force test of related technologies, the two large protrusions on the top and bottom of the battery cell may not be completely symmetrical. This can lead to the battery cell being subjected to horizontal thrust or tension after being subjected to vertical pressure from the press, resulting in damage to the battery cell. At the same time, if a horizontal clamp is simply used to hold the side wall (not the large surface) of the battery cell to provide support when the press applies pressure to the large surface, the contact between the side wall of the battery cell and the clamp may damage the battery cell or the clamp. Furthermore, the side wall with the terminal post may come into contact with the clamp, causing self-discharge, resulting in low reliability.
[0040] Based on the above considerations, in order to solve the problem of insufficient reliability of battery cells during expansion force testing, the inventors, after in-depth research, designed an expansion force testing fixture. This fixture aims to provide support for the battery cells from the side wall (not the large surface) during the expansion force testing process, and can reduce the probability of damage to the battery cells or the expansion force testing fixture itself during the testing process.
[0041] The expansion force testing fixture disclosed in this application can be used, but is not limited to, for expansion force testing of square battery cells and pouch battery cells, aiming to improve the reliability of battery cells during expansion force testing and reduce the probability of battery cells being damaged during testing.
[0042] Please refer to the reference. Figures 1 to 3 , Figure 1 This is a three-dimensional structural schematic diagram of the expansion force testing fixture in one embodiment of this application; Figure 2 This is a top view of the expansion force testing fixture in one embodiment of this application; Figure 3 for Figure 2 An enlarged view of part A of the expansion force testing fixture shown.
[0043] This application provides an expansion force testing fixture 100, which includes a base 10, a clamping body 20, and a protective body 30. The base 10 includes a first surface 11 for supporting a battery cell 200. The clamping body 20 is disposed on the base 10 and configured to clamp and position the battery cell 200 in a direction parallel to the first surface 11. The protective body 30 is connected to the clamping body 20 and is used to contact the battery cell 200.
[0044] The expansion force testing fixture 100 is a device used to measure the change in expansion force of a battery. It is designed to clamp and position the battery cell 200 to improve the structural stability of the battery cell 200 during expansion force testing. At the same time, it can also improve the consistency of positioning conditions for different battery cells 200 during expansion force testing.
[0045] The base 10 serves to support the battery cell 200 to be tested for expansion force and to provide an installation position for the clamping body 20 so that the clamping body 20 can clamp and position the battery cell 200 supported on the base 10.
[0046] The substrate 10 includes a first surface 11, which is used to support the battery cell 200. The first surface 11 can be any surface of the outer wall of the substrate 10, and the first surface 11 is the surface of the substrate 10 used to support the battery cell 200. During the expansion force test, the press applies pressure from the side of the substrate 10 close to the first surface 11 to work together with the substrate 10 to compress the battery cell 200. The expansion force of the battery cell 200 is then determined by the pressure sensing device on the press.
[0047] In these embodiments of this application, the first surface 11 can be set as the top surface of the base 10, that is, a plane perpendicular to the direction of gravity, so as to reduce the influence of gravity on the positioning accuracy of the battery cell 200.
[0048] The clamping body 20 is configured to clamp and position the battery cell 200 in a direction parallel to the first surface 11. The clamping body 20 can be an integral structure or a split structure, so that after the battery cell 200 is placed on the first surface 11, the clamping body 20 can clamp and position the battery cell 200 in a direction parallel to the first surface 11.
[0049] The clamping body 20 is disposed on the base 10. In embodiments where the clamping body 20 is an integral structure, the clamping body 20 and the base 10 can be fixedly connected by welding, bonding, or even integral molding to improve the consistency between the clamping body 20 and the base 10 and increase the structural reliability of the clamping body 20. In embodiments where the clamping body 20 is a split structure, at least a portion of the multiple split structures of the clamping body 20 can be provided only on the first surface 11 of the base 10, so that the structural shape of the clamping body 20 can be adjusted according to the specifications and dimensions of the battery cell 200, thereby making the expansion force testing fixture 100 more applicable.
[0050] In these embodiments of the present application, the clamping body 20 may be configured as a strip structure or a block structure according to the clamping requirements.
[0051] The protective body 30 is connected to the clamping body 20 and is used to contact the battery cell 200. This means that after the battery cell 200 is clamped by the clamping body 20, the protective body 30 is placed between the clamping body 20 and the battery cell 200. By reducing the clamping stiffness of the battery cell through its own flexibility, when the battery cell 200 is deformed under pressure during the test, the protective body 30 can support the battery cell 200 in a direction parallel to the first surface 11, thereby reducing the risk of damage to the battery cell 200 during the test.
[0052] The protective body 30 is connected to the clamping body 20. In a possible implementation, the protective body 30 and the clamping body 20 are detachably connected through structures such as slots, buckles, and sliding grooves to reduce the difficulty of disassembling and assembling the protective body 30 and improve the efficiency of maintenance or replacement of the protective body 30 after use.
[0053] It should be noted that the relevant technology is usually used to test the expansion force of fresh battery cells 200, and the expansion force test can only be performed when the battery cells 200 are in a charging and discharging state. The reason is that the logic of the expansion force test in the relevant technology is as follows: first, the battery cell 200 is compressed with a press, then the battery cell 200 is controlled to charge and discharge, and then the press is used to sense the expansion force generated by the battery cell 200 during the charging and discharging process. Based on this, it is not possible to accurately test the expansion force of battery cells 200 that have been used for a long time and have already deformed under the action of expansion force.
[0054] In these embodiments of this application, by designing the expansion force testing fixture 100, the method of testing the expansion force of the battery cell 200 in related technologies is changed. Therefore, the expansion force testing fixture 100 can be used to test the expansion force of the battery cell 200 that has already deformed under the action of expansion force. The logic of the expansion force testing fixture 100 provided in this application for testing the expansion force of the battery cell 200 is as follows: First, the battery cell 200 is clamped and positioned by the base 10 and the clamping body 20, and the protective body 30 is located between the battery cell 200 and the clamping body 20. Then, referring to the dimensional data of the battery cell 200 at the factory, the dimensions of the battery cell 200 in the extrusion direction are extruded to the factory dimensions using a press. Finally, the expansion force of the battery cell 200 is determined by the press.
[0055] Based on this, the embodiments of this application configure the clamping body 20 to clamp and position the battery cell 200 in a direction parallel to the first surface 11, and provide a protective body 30 for contacting the battery cell 200. This allows the clamping body 20 to position the battery cell 200 while the protective body 30 reduces the contact stiffness between the wall of the battery cell 200 perpendicular to the first surface 11 and the clamping body 20 during testing, thereby reducing the risk of damage to the battery cell 200 during the expansion force test.
[0056] In the technical solution of this application embodiment, by setting a protective body 30 connected to the clamping body 20, the clamping body 20 contacts the battery cell 200 through the protective body 30, thereby positioning the battery cell 200. The flexibility of the protective body 30 itself can provide elastic support for the battery cell 200 in the direction parallel to the first surface 11, reducing the risk of structural damage to the battery cell 200 when subjected to uneven stress, thereby improving the reliability of the expansion force testing fixture.
[0057] In some embodiments, the clamping body 20 includes a first clamping member 21 and a second clamping member 22, which are arranged opposite each other along a straight line, and a protective body 30 is disposed on at least one of the first clamping member 21 and the second clamping member 22.
[0058] The clamping body 20 includes a first clamping member 21 and a second clamping member 22, which means that the clamping body 20 has a split structure. One clamping body 20 includes two components, the first clamping member 21 and the second clamping member 22, and the first clamping member 21 and the second clamping member 22 are respectively disposed on the base 10.
[0059] The first clamping member 21 and the second clamping member 22 are arranged opposite each other along a straight line. When the expansion force testing fixture 100 clamps and positions the battery cell 200, the first clamping member 21 and the second clamping member 22 can be used to clamp the battery cell 200 on the opposite wall, thereby at least restricting the degree of freedom of the battery cell 200 in the direction in which the first clamping member 21 and the second clamping member 22 are arranged opposite each other, so as to realize the clamping and positioning of the battery cell 200.
[0060] The protective body 30 is provided in at least one of the first clamping member 21 and the second clamping member 22, which means that the protective body 30 can be provided on the side of the first clamping member 21 near the second clamping member 22, and / or the protective body 30 is provided on the side of the second clamping member 22 near the first clamping member 21, so that after the clamping body 20 clamps and positions the battery cell 200, the protective body 30 can provide protection for the battery cell 200.
[0061] In these embodiments of the present application, by setting the clamping body 20 to include a first clamping member 21 and a second clamping member 22 arranged opposite each other along a straight line, expansion force tests can be performed on some different battery cells 200 with the same dimensional parameters, thus expanding the scope of application.
[0062] For example, in some embodiments, multiple battery cells 200 have the same height dimension, but different length and thickness dimensions. In this case, the different battery cells 200 can be clamped and positioned by controlling the height direction of the battery cell 200 to be such that the first clamping member 21 and the second clamping member 22 are set opposite each other, and subsequent expansion force tests can be performed. The protective body 30 can be used to contact at least one side wall of the battery cell 200 that is relatively weak and vulnerable, such as the wall of the battery cell 200 where the pole is provided.
[0063] In some embodiments, at least one of the first clamping member 21 and the second clamping member 22 is position-adjustable along the direction in which the first clamping member 21 and the second clamping member 22 are disposed opposite to each other.
[0064] At least one of the first clamping member 21 and the second clamping member 22 is position-adjustable. In a possible implementation, a guide groove 102 is provided on the first surface 11 of the base 10. The guide groove 102 is arranged along the relative arrangement direction of the first clamping member 21 and the second clamping member 22, and at least one of the first clamping member 21 and the second clamping member 22 slides in cooperation with the guide groove 102, thereby adjusting the distance between the first clamping member 21 and the second clamping member 22.
[0065] In some embodiments, at least one of the first clamping member 21 and the second clamping member 22 may be mounted on the base 10, so that it can reciprocate along the direction in which the first clamping member 21 and the second clamping member 22 are arranged opposite each other under the driving action of the driving member, thereby adjusting the distance between the first clamping member 21 and the second clamping member 22 to adapt to battery cells 200 of different sizes.
[0066] In some embodiments, the number of clamping bodies 20 is at least two, wherein the clamping directions of the two clamping bodies 20 intersect.
[0067] The number of clamping bodies 20 is at least two. This means that the number of clamping bodies 20 can be set according to positioning requirements and the external shape of the battery cell 200. In these embodiments of the present application, the battery cell 200 is rectangular in shape. In this case, the number of clamping bodies 20 can be two, and the two clamping bodies 20 clamp the battery cell 200 from the longer side and the shorter side, respectively. In some embodiments where the battery cell 200 has an irregular shape, the number of clamping bodies 20 can also be three, four, etc., but is not limited to.
[0068] In a plurality of clamping bodies 20, the clamping directions of two clamping bodies 20 intersect, meaning that the first clamping member 21 and the second clamping member 22 in one clamping body 20 are arranged along a first direction, and the first clamping member 21 and the second clamping member 22 in the other clamping body 20 are arranged along a second direction. Both the first direction and the second direction are parallel to the first surface 11, and the first direction and the second direction intersect.
[0069] Based on this, in some embodiments, the number of clamping bodies 20 can be multiple, and the first clamping member 21 and the second clamping member 22 in some clamping bodies 20 are arranged along the first direction as in the aforementioned embodiments, while the first clamping member 21 and the second clamping member 22 in some clamping bodies 20 are arranged along the second direction as in the aforementioned embodiments. That is to say, in at least two clamping bodies 20, at least two clamping bodies 20 have intersecting clamping directions.
[0070] In this way, at least two clamping bodies 20 can be used to clamp and position the battery cell 200 from at least two different directions, thereby restricting the degree of freedom of the battery cell 200 supported on the first surface 11 from at least two directions, which can further improve the positioning effect of the battery cell 200.
[0071] In these embodiments of the present application, two clamping bodies 20 may be arranged such that the relative arrangement directions of the first clamping member 21 and the second clamping member 22 are perpendicular to each other, so that the clamping force on the battery cell 200 is more uniform and the stability of the clamping body 20 clamping the battery cell 200 is improved.
[0072] In some embodiments, one of the first clamping member 21 and the second clamping member 22 is a fixed wall that is fixedly connected to the base 10, and the other is a movable wall that can move relative to the base 10 in a direction toward or away from the fixed wall.
[0073] In these embodiments of this application, one of the first clamping member 21 and the second clamping member 22 is a fixed wall, and the other is a movable wall. The fixed wall is fixedly connected to the base 10, and the movable wall can move relative to the base 10 in a direction toward or away from the fixed wall. In this way, the fixed wall can be used as two fixed walls to provide pre-positioning for the battery cell 200. That is, the approximate position of the battery cell 200 can be determined by the two fixed walls, and then the battery cell 200 can be clamped and positioned by adjusting the two movable walls respectively, thereby improving the accuracy of the positioning of the battery cell 200.
[0074] The fixing connection between the fixed wall and the base 10 can be welding, gluing, or even integral molding.
[0075] In some embodiments, there are two clamping bodies 20, and the two fixed walls of the two clamping bodies 20 are connected and cooperate with the base 10 to form a prepositioning area 101, which is used to place the battery cell 200.
[0076] Two fixed walls are connected so that the positioning position of the battery cell 200, i.e., the pre-positioning area 101, can be more accurately determined on a plane parallel to the first surface 11. After the battery cell 200 is placed on the first surface 11, the pre-positioning area 101 can be used to quickly position the battery cell 200, thereby improving the efficiency of expansion force testing of the battery cell 200 on the production line.
[0077] The fixed wall is actually the precise location of the battery cell 200. When the clamping body 20 clamps and positions the battery cell 200, the movable wall pushes the battery cell 200 toward the fixed wall, and finally works with the fixed wall to clamp and position the battery cell 200.
[0078] In these embodiments of the present application, by setting two fixed wall connections to form a structure similar to the letter "L", the corner at the connection of the two fixed walls can be used to provide pre-positioning for the battery cell 200, thereby achieving fast and accurate placement of the battery cell 200.
[0079] In some embodiments, the expansion force testing fixture 100 further includes a drive assembly 40, which includes a fixed base 41 and a drive member 42. The fixed base 41 is fixedly connected to the base 10, the drive member 42 is disposed on the fixed base 41, and the output end of the drive member 42 cooperates with the first clamping member 21 and / or the second clamping member 22.
[0080] The fixed base 41 serves to support the driving member 42. In some embodiments, the fixed base 41 can also cooperate with the driving member 42 to enable the driving member 42 to move forward and backward, and drive the movable wall to move in the direction of approaching or moving away from the fixed wall.
[0081] The output end of the driving member 42 cooperates with the first clamping member 21 and / or the second clamping member 22, which means that the driving member 42 drives the movable wall to move forward and backward through the contact between the output end and the movable wall.
[0082] For example, in some embodiments, the fixing seat 41 and the driving member 42 can be configured as a lead screw assembly; in this case, the fixing seat 41 can serve as a lead screw sleeve, and the driving member 42 is the lead screw, with one end of the lead screw abutting against the movable wall. In this way, the operator can rotate the lead screw to move it axially forward and backward relative to the lead screw sleeve, thereby driving the movable wall abutting against the end of the lead screw to move forward, and finally working together with the fixing wall to clamp and position the battery cell 200.
[0083] In some embodiments, the fixed base 41 and the driving member 42 may be configured as a cylinder assembly. In this case, the fixed base 41 mainly serves for support and installation, and the driving member 42 can be a cylinder, with its output shaft connected to the movable wall. In this way, the operator can move the movable wall forward or backward by operating the extension and retraction of the cylinder.
[0084] In some embodiments, the expansion force testing fixture 100 further includes a pressure sensor 50, which is disposed on the protective body 30 and is used to transmit the pressure value borne by the protective body 30.
[0085] A pressure sensor 50 is disposed on the protective body 30 to quantify the pressure value exerted on the protective body 30. During the stage when the battery cell 200 is clamped by the expansion force testing fixture 100, the pressure sensor 50 can indicate the clamping force of the clamping body 20 on the battery cell 200, allowing the operator to more accurately control the clamping force of the clamping body 20.
[0086] In these embodiments of the present application, by precisely controlling the clamping force of the clamping body 20 on the battery cell 200, the protective body 30 can reduce the stress between itself and the battery cell 200 while providing good clamping force, thereby reducing the risk of damage to the protective body 30's own structure under excessive stress. At the same time, when the battery cell 200 is subjected to expansion force testing, it can provide good rebound support for the battery cell 200, reducing the risk of damage to the battery cell 200.
[0087] For example, in these embodiments of the present application, the clamping force of the clamping body 20 on the battery cell 200 can be controlled between 5N and 10N by the pressure sensor 50.
[0088] In some embodiments, the pressure sensor 50 is disposed between the protective body 30 and the clamping body 20. This reduces the impact of the pressure sensor 50 on the protective body 30's function of protecting the battery cell 200. Simultaneously, disposing of the pressure sensor 50 between the protective body 30 and the clamping body 20 facilitates its installation and removal, reducing the difficulty of replacing or repairing it.
[0089] In some embodiments, the first surface 11 is used to support the large surface of the battery cell 200. When the press performs an expansion force test on the battery cell 200, pressure is applied to the large surface of the battery cell 200 to perform the expansion force test. Since the large surface of the battery cell 200 is more prone to deformation due to expansion force, this design can further improve the testing accuracy of the expansion force testing fixture.
[0090] In some embodiments, the clamping body 20 and the protective body 30 are glued together. This improves the structural consistency between the clamping body 20 and the protective body 30, reduces the possibility of the protective body becoming loose or displaced during the operation of the expansion force testing fixture, and further enhances the reliability of the expansion force testing fixture.
[0091] In these embodiments of the present application, strong adhesives such as epoxy adhesives, acrylic adhesives, and UV-curable adhesives can be used to bond and fasten the clamping body 20 and the protective body 30.
[0092] In some embodiments, the protective body 30 is a polyurethane component, a silicone rubber component, an epoxy resin component, a polyimide component, a polytetrafluoroethylene component, a polyvinyl chloride component, or a polyamide component.
[0093] The selection of the protective body 30 needs to consider both hardness and elasticity. Hardness can reduce the risk of damage to the protective body 30 itself during the expansion force test and provide good clamping force for the battery cell 200; elasticity allows the protective body 30 to provide good elastic support for the battery cell 200 when it is subjected to pressure deformation, reducing the risk of deformation of the battery cell 200 under the extrusion of the press.
[0094] This application only describes the protective body 30 as a polyurethane component as an example. The following is the preparation process of the protective body 30:
[0095] Prepare the following raw materials: polyols, isocyanates, and chain extenders. The polyols may include polycaprolactone polyols, pentaerythritol phosphates, polyether polyols, or poly(1,4-butanediol adipate); the isocyanates may include toluene diisocyanate and diphenylmethane diisocyanate; the chain extenders may include a mixture of 2,4- and 2,6-dimethylthiotoluene diamine, 3,3'-dichloro-4,4'-diaminodiphenylmethane, and 2,4-diamino-3,5-dimethylthiochlorobenzene.
[0096] The protective body 30 material was synthesized according to the following process: A polyol was added to a prepared three-necked flask and dehydrated under negative pressure at 110°C for 2.5 h. After cooling to 65°C, an appropriate amount of isocyanate was added, and the mixture was reacted at 80°C for 2.5 h. Compound 1 was then obtained under vacuum. The chain extender was treated under the same conditions, i.e., dehydrated under negative pressure at 110°C for 2.5 h, to obtain compound 2. Compound 1 and compound 2 were mixed and placed in a mold at 100°C for pressure vulcanization for 16 h. Finally, the mixture was left in air for 7 days to mature, yielding the final product material.
[0097] In some embodiments, the hardness of the protective body 30 is not less than Shore hardness D60 and not greater than Shore hardness D70; and / or, the tensile strength of the protective body is not less than 44 MPa and not greater than 46 MPa; and / or, the tear strength of the protective body is not less than 155 MPa and not greater than 163 MPa; and / or, the flexural strength of the protective body is not less than 18 MPa and not greater than 20 MPa; and / or, the impact strength of the protective body is not less than 109 MPa and not greater than 114 MPa.
[0098] In these embodiments of the present application, after obtaining the finished material of the protective body 30, the hardness and elasticity properties of the finished material of the protective body 30 can be tested.
[0099] In the hardness performance test, the Shore hardness test can be conducted according to GB / T 2411-2008. In the elastic performance test, tear and tensile strength can be tested according to GB / T 528-1998, impact strength can be tested according to GB / T 1041.1-2008, and flexural strength can be tested according to GB / T 9341-2008.
[0100] It should be noted that the hardness and elasticity of the protective body 30 depend on the type of polyol, the ratio of isocyanates used, the type of chain extender, and the ratio of compound 1 to compound 2. In these embodiments of this application, pentaerythritol phosphate can be selected as the polyol, the ratio of toluene diisocyanate / diphenylmethane diisocyanate can be 6:4, 3,3'-dichloro-4,4'-diaminodiphenylmethane can be used as the chain extender, and the ratio of compound 1 to compound 2 can be set to 10:1. This ensures that the hardness of the obtained protective body 30 material reaches Shore hardness D70, while the elastic properties are as follows: tensile strength 45.9 MPa, tear strength 162.8 MPa, flexural strength 19.2 MPa, and impact strength 113.5 MPa. This allows the protective body 30 to protect the structure of the battery cell 200 from damage while ensuring that it remains undamaged during normal testing.
[0101] Please refer to the reference. Figures 1 to 4 , Figure 4 This is a schematic diagram of the planar structure of the expansion force testing device in one embodiment of this application.
[0102] This application also provides an expansion force testing device 1000, which includes an expansion force testing fixture 100 and a press 300 as provided in any of the foregoing embodiments.
[0103] The working process of the expansion force testing equipment 1000 is as follows:
[0104] Measure the thickness h1 of the battery cell 200 under test, and check the designed thickness h0 of the battery cell 200 under test;
[0105] The battery cell 200 to be tested is fixed to the expansion force testing fixture 100. During the fixing process, the clamping force is controlled by the pressure sensor 50 to not exceed 10N.
[0106] Fix the expansion force testing fixture 100, on which the battery cell 200 to be tested is mounted, onto the sample stage of the material testing machine.
[0107] The program is set so that the press 300 can compress the thickness of the battery cell 200 to the initial design thickness. In this step, the displacement stroke of the press 300 can be controlled as h1-h0, and the extrusion force is recorded. This extrusion force is the expansion force of the battery cell 200.
[0108] Based on some embodiments of this application, please refer to the following: Figures 1 to 4This application provides an expansion force testing fixture 100, which includes a base 10, a clamping body 20, a protective body 30, a driving assembly 40, and a pressure sensor 50. The base 10 includes a first surface 11 for supporting a battery cell 200. The clamping body 20 is disposed on the base 10 and configured to clamp and position the battery cell 200 in a direction parallel to the first surface 11. The protective body 30 is connected to the clamping body 20 and is used to contact the battery cell 200.
[0109] The base 10 serves to support the battery cell 200 to be tested for expansion force and to provide an installation position for the clamping body 20 so that the clamping body 20 can clamp and position the battery cell 200 supported on the base 10.
[0110] The clamping body 20 is configured to clamp and position the battery cell 200 in a direction parallel to the first surface 11. The clamping body 20 can be an integral structure or a split structure, so that after the battery cell 200 is placed on the first surface 11, the clamping body 20 can clamp and position the battery cell 200 in a direction parallel to the first surface 11.
[0111] The protective body 30 is connected to the clamping body 20 and is used to contact the battery cell 200. This means that after the battery cell 200 is clamped by the clamping body 20, the protective body 30 is placed between the clamping body 20 and the battery cell 200. By reducing the clamping stiffness of the battery cell through its own flexibility, when the battery cell 200 is deformed under pressure during the test, the protective body 30 can support the battery cell 200 in a direction parallel to the first surface 11, thereby reducing the risk of damage to the battery cell 200 during the test.
[0112] A pressure sensor 50 is disposed on the protective body 30 to quantify the pressure value exerted on the protective body 30. During the stage when the battery cell 200 is clamped by the expansion force testing fixture 100, the pressure sensor 50 can indicate the clamping force of the clamping body 20 on the battery cell 200, allowing the operator to more accurately control the clamping force of the clamping body 20.
[0113] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0114] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.
Claims
1. A tooling for testing expansion force, characterized in that, include: The substrate includes a first surface for supporting a single battery cell; A clamping body is disposed on the substrate and configured to clamp and position the battery cell in a direction parallel to the first surface; A protective body is attached to the clamping body and is used to contact the battery cell.
2. The expansion force testing fixture according to claim 1, characterized in that, The clamping body includes a first clamping member and a second clamping member, which are arranged opposite each other along a straight line, and the protective body is provided on at least one of the first clamping member and the second clamping member.
3. The expansion force testing fixture according to claim 2, characterized in that, Along the direction in which the first clamping member and the second clamping member are disposed opposite to each other, the position of at least one of the first clamping member and the second clamping member is adjustable.
4. The expansion force testing fixture according to claim 2, characterized in that, The number of clamping bodies is at least two, wherein the clamping directions of the two clamping bodies intersect.
5. The expansion force testing fixture according to claim 4, characterized in that, One of the first clamping member and the second clamping member is a fixed wall that is fixedly connected to the base, and the other is a movable wall that can move relative to the base in a direction toward or away from the fixed wall.
6. The expansion force testing fixture according to claim 5, characterized in that, The number of clamping bodies is two, and the two fixed walls of the two clamping bodies are connected and cooperate with the base to form a pre-positioning area, which is used to place the battery cell.
7. The expansion force testing fixture according to claim 2, characterized in that, The expansion force testing fixture also includes: A drive assembly includes a fixed base and a drive member. The fixed base is fixedly connected to the base, the drive member is disposed on the fixed base, and the output end of the drive member cooperates with the first clamping member and / or the second clamping member.
8. The expansion force testing fixture according to claim 7, characterized in that, The fixed base and the driving member are configured as a lead screw assembly; or, the fixed base and the driving member are configured as a cylinder assembly.
9. The expansion force testing fixture according to claim 1, characterized in that, The expansion force testing fixture also includes a pressure sensor, which is disposed on the protective body and is used to transmit the pressure value borne by the protective body.
10. The expansion force testing fixture according to claim 9, characterized in that, The pressure sensor is disposed between the protective body and the clamping body.
11. The expansion force testing fixture according to claim 1, characterized in that, The first surface is used to support the large surface of the battery cell.
12. The expansion force testing fixture according to any one of claims 1 to 11, characterized in that, The clamping body is glued and fixed to the protective body.
13. The expansion force testing fixture according to any one of claims 1 to 11, characterized in that, The protective body is made of polyurethane, silicone rubber, epoxy resin, polyimide, polytetrafluoroethylene, polyvinyl chloride, or polyamide.
14. The expansion force testing fixture according to claim 13, characterized in that, The hardness of the protective body is not less than Shore hardness D60 and not greater than Shore hardness D70; and / or, The tensile strength of the protective body is not less than 44 MPa and not greater than 46 MPa; and / or, The tear strength of the protective body is not less than 155 MPa and not greater than 163 MPa; and / or, The bending strength of the protective body is not less than 18 MPa and not greater than 20 MPa; and / or, The impact strength of the protective body is not less than 109 MPa and not greater than 114 MPa.
15. An expansion force testing device, characterized in that, Includes the expansion force testing fixture as described in any one of claims 1 to 14.