Test fixture

Abstract

The utility model provides a test fixture. The test fixture comprises at least two clamping pieces which are oppositely arranged, a clamping space is formed between the two clamping pieces, the clamping pieces are provided with avoiding openings, and the avoiding openings penetrate through the clamping pieces in the thickness direction of the clamping pieces so that the clamping space can be communicated with the avoiding openings; the surfaces of the sides, close to each other, of the two clamping pieces are clamping faces, and the heat insulation layers are arranged on the clamping faces. According to the utility model, the problems in the prior art that the battery cell heat insulation quantity heat test fixture is poor in use performance and is easy to cause inaccurate test results are solved.

Description

Technical Field

[0001] This utility model relates to the field of battery testing technology, and more specifically, to a test fixture. Background Technology

[0002] The principle of battery thermal insulation testing is mainly to provide an approximately adiabatic environment by accurately tracking the temperature and avoiding heat exchange between the sample under test and the environment. In this environment, the exothermic behavior of the sample under test is tested and analyzed to simulate the thermal characteristics of the exothermic reaction process when the internal heat of the battery cannot be dissipated in time, thereby obtaining battery thermal performance parameters and stability assessment.

[0003] There are two testing methods for battery insulation thermal testing: with clamps and without clamps. The test method without clamps will cause the battery to swell due to high temperature and gas expansion, greatly increasing the internal space of the battery and affecting the opening of the battery pressure relief valve. The test scenario is inconsistent with the thermal runaway valve opening scenario in the actual application of power batteries, which will affect the accuracy and reference of the test data.

[0004] The clamped test primarily uses high-strength metal parallel plates as clamps. The test battery is placed between the two parallel plates and then connected by bolts. During the test, this method mainly affects the later stages of the battery test. When the equipment detects and determines that the self-generated heat temperature has been reached, the equipment will stop heating the test sample and instead track the battery temperature, keeping it consistent with the battery temperature. The battery is in a state of no heat conduction and no heat radiation, in a near-adiabatic environment. The battery generates heat through internal reactions, causing the temperature to rise, thus reaching the thermal runaway temperature. If there is no heat insulation material between the clamp and the test sample, the battery's self-generated heat will be transferred to the clamp. The clamp will absorb some of the battery's self-generated heat, causing the battery to heat up more slowly, or even fail to reach the thermal runaway temperature, resulting in test failure. This is especially significant and common for lithium iron phosphate batteries, which have higher thermal stability parameters and are considered safer.

[0005] Simply adding insulation material between the parallel plate clamp and the test sample will affect the accuracy of the data in the "heat-wait-search" mode of the adiabatic thermal test. The equipment heats the test sample from the initial temperature, increasing the temperature to a preset step each time, then switching to a wait mode to more accurately search for the sample's self-exothermic reaction. After the wait period, the system automatically enters a search mode to detect the sample's temperature rise rate. If the sample's temperature rise rate exceeds a preset sensitivity (typically 0.02℃ / min), it is determined that the sample exhibits self-exothermic behavior and enters the adiabatic mode; otherwise, it continues to rise to a higher preset temperature. Adding insulation material will affect the time and accuracy of the heat transfer to the battery. The battery surface temperature is higher than the internal temperature. When the equipment detects that the surface temperature has reached equilibrium with the sample, the actual internal temperature of the battery has not yet been reached, resulting in a detected self-exothermic starting temperature that is higher than the actual self-exothermic temperature, thus affecting the test results.

[0006] Therefore, existing technologies suffer from poor performance of battery cell insulation thermal testing fixtures, which can easily lead to inaccurate test results. Utility Model Content

[0007] The main purpose of this utility model is to provide a test fixture to solve the problem that the existing battery cell insulation thermal test fixtures have poor performance and are prone to inaccurate test results.

[0008] To achieve the above objectives, according to one aspect of the present invention, a test fixture is provided, comprising: at least two clamping members disposed opposite to each other, a clamping space between the two clamping members, and a clearance opening in each clamping member, the clearance opening penetrating the clamping member along the thickness direction so that the clamping space communicates with the clearance opening; and a heat insulation layer, wherein the surface of the two clamping members on the side close to each other is the clamping surface, and the heat insulation layer is disposed on the clamping surface.

[0009] Furthermore, the clamping member includes: a clamping frame having a hollow area; and a partition disposed on the clamping frame to divide the hollow area into multiple clearance openings.

[0010] Furthermore, the test fixture also includes fasteners that pass through the two clamping members respectively.

[0011] Furthermore, the clamping member has a mounting protrusion corresponding to the fixing member, and the fixing member passes through the mounting protrusion.

[0012] Furthermore, there are multiple fasteners and mounting protrusions, with multiple mounting protrusions arranged around the periphery of the clamping member, and each mounting protrusion is provided with at least one fastener.

[0013] Furthermore, at least a portion of the mounting protrusions are located at the corner of the clamping member, and at least another portion of the mounting protrusions are located on the side of the clamping member.

[0014] Furthermore, two mounting protrusions are provided at each corner of the clamping member, and the protrusion directions of the two mounting protrusions located at the same corner are perpendicular to each other.

[0015] Furthermore, the clamping member has multiple clearance openings, and the multiple clearance openings of the two clamping members correspond one to one and are arranged opposite each other.

[0016] Furthermore, the sum of the opening areas of all clearance openings of the same clamping member is greater than or equal to 60% of the area of ​​the clamping surface.

[0017] Furthermore, the clamping element is made of metal.

[0018] Applying the technical solution of this utility model, the test fixture in this application includes: at least two clamping members arranged opposite to each other and a heat insulation layer. There is a clamping space between the two clamping members, and the clamping members have clearance openings that penetrate the clamping members along the thickness direction so that the clamping space communicates with the clearance openings; the surfaces of the two clamping members that are close to each other are clamping surfaces, and the heat insulation layer is disposed on the clamping surfaces.

[0019] When using the test fixture of this application, the clamping space between the two clamping members allows for the clamping of the battery under test, thus achieving a restraining effect. Simultaneously, the clamping members also have clearance openings, which suppress the expansion during the battery's thermal runaway process without affecting the battery's depressurization and normal venting. Furthermore, since the side of the two clamping members adjacent to each other in this application also has a heat insulation layer, the test fixture of this application can have a double-layer structure: one layer is the clamping members, and the other is the heat insulation layer. This design ensures the structural stability of the test fixture through the clamping members, while the heat insulation layer reduces the transfer of heat from the battery's self-generated heat to the clamping members, preventing a slowdown in the temperature rise of the battery under test. In other words, the heat insulation layer helps the battery under test reach the thermal runaway critical temperature, making battery testing easier and faster, and ensuring the accuracy of the test results. On the other hand, the clearance openings in this application also allow the heating device to directly heat the battery during the test, thereby improving heating efficiency and testing speed. Therefore, the test fixture in this application effectively solves the problem that the existing battery cell insulation thermal test fixtures have poor performance and are prone to inaccurate test results. Attached Figure Description

[0020] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings:

[0021] Figure 1 A schematic diagram of the structure of a test fixture according to a specific embodiment of this application is shown.

[0022] The above figures include the following reference numerals:

[0023] 10. Clamping component; 11. Clearance opening; 12. Clamping frame; 13. Divider; 14. Mounting protrusion; 20. Fixing component; 30. Object to be measured. Detailed Implementation

[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present utility model or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.

[0025] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0026] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0027] To address the problem that existing battery cell insulation thermal testing fixtures have poor performance and easily lead to inaccurate test results, this application provides a testing fixture.

[0028] like Figure 1 As shown, the test fixture in this application includes at least two opposing clamping members 10 and a heat insulation layer. A clamping space exists between the two clamping members 10, and each clamping member 10 has a clearance opening 11 that extends through the clamping member 10 along its thickness direction, so that the clamping space communicates with the clearance opening 11. The surfaces of the two clamping members 10 that are close to each other are clamping surfaces, and the heat insulation layer is disposed on the clamping surfaces.

[0029] When using the test fixture of this application, the clamping space between the two clamping members 10 allows for the clamping of the battery under test, thus achieving a restraining effect. Simultaneously, the clamping members 10 also have clearance openings 11, which suppress the expansion during the battery's thermal runaway process without affecting the battery's depressurization and normal venting. Furthermore, since the side of the two clamping members 10 that is close to each other in this application also has a heat insulation layer, the test fixture of this application can have a double-layer structure: one layer is the clamping members 10, and the other layer is the heat insulation layer. This configuration ensures the structural stability of the test fixture through the clamping members 10, while the heat insulation layer reduces the transfer of heat from the battery's self-generated heat to the clamping members 10, preventing a slowdown in the temperature rise of the battery under test. In other words, the heat insulation layer facilitates the battery under test reaching the thermal runaway critical temperature, making battery testing easier and faster, and ensuring the accuracy of the test results. On the other hand, by providing the clearance opening 11 in this application, the heating device can directly heat the battery through the clearance opening 11 during the test, thereby improving heating efficiency and test speed. Therefore, the test fixture in this application effectively solves the problem of poor performance and inaccurate test results of the existing cell insulation thermal test fixtures.

[0030] Of course, in this application, the object to be tested 30 clamped between the two clamping members 10 can be a battery or a battery cell. Alternatively, the object to be tested 30 can also be other objects requiring adiabatic thermal measurement.

[0031] Specifically, the clamping member 10 has multiple clearance openings 11, and the clearance openings 11 of the two clamping members 10 are one-to-one and arranged opposite each other. By setting multiple clearance openings 11, it is possible to heat the battery more easily and conveniently during the testing process, thereby ensuring the heating efficiency and heating speed of the battery. Furthermore, the one-to-one correspondence and opposite arrangement of the clearance openings 11 of the two clamping members 10 ensures a more uniform temperature distribution of the battery, thereby ensuring the accuracy of the battery test results.

[0032] Preferably, the clamping member 10 is made of metal. By setting the clamping member 10 to a structure made of metal, the structural strength and rigidity of the test fixture can be effectively guaranteed, thereby better suppressing the expansion during the thermal runaway process of the battery.

[0033] Furthermore, in this application, the insulation material of the insulation layer needs to possess good thermal insulation performance and chemical stability to ensure the accuracy and safety of the tests. Therefore, the insulation material of the insulation layer in this application can be ceramic fiber, aluminosilicate fiber, aerogel, polyimide film, glass fiber, etc. Ceramic fiber is a lightweight, high-temperature insulation material with good thermal stability and low thermal conductivity, suitable for use in high-temperature environments. Aluminosilicate fiber is similar to ceramic fiber, possessing good thermal insulation performance and chemical stability, and is not easily decomposed at high temperatures. Aerogel is an ultra-lightweight material with ultra-low thermal conductivity, offering superior insulation performance compared to traditional materials, but at a higher cost. Polyimide film has good thermal and chemical stability, can be used over a wide temperature range, and possesses a certain degree of mechanical strength. Glass fiber has high mechanical strength and heat resistance, making it an economical and practical insulation material. Of course, the insulation layer in this application can also be composed of multiple materials.

[0034] In one specific embodiment of this application, the clamping member 10 includes a clamping frame 12 and a partition 13. The clamping frame 12 has a hollow area; the partition 13 is disposed on the clamping frame 12 to divide the hollow area into multiple clearance openings 11. That is, in this embodiment, the clamping member 10 is a frame structure. Furthermore, in this application, the clamping frame 12 and the partition 13 can be integrally formed. Also, in this application, the clamping frame 12 can be a rectangular frame, and the partition 13 can be a cross-shaped frame disposed inside the rectangular frame, with the four ends of the cross-shaped frame connected to the midpoints of the four sides of the rectangular frame, thereby ensuring more uniform force on the battery when clamping it using the test fixture of this application. Simultaneously, this arrangement also ensures a more uniform distribution of the multiple clearance openings 11, thereby ensuring a more uniform temperature distribution of the battery during testing.

[0035] Of course, in this application, the clamping frame 12 and the partition 13 can also be of other shapes, as long as they can stably clamp the battery. Furthermore, in the above embodiment, the clearance opening 11 is also rectangular, so when the shape of the partition 13 changes, the shape of the clearance opening 11 can also be adjusted accordingly.

[0036] Furthermore, in the above embodiments, the clamping member 10 is a frame structure. Of course, in this application, the clamping member 10 can also be a plate structure, and the plate structure has multiple clearance openings 11.

[0037] Optionally, the test fixture also includes a fixing member 20, which passes through the two clamping members 10 respectively. Furthermore, in this application, the fixing member can be a bolt, pin, or other similar structure. By providing the fixing member 20, the test fixture can stably clamp the battery under test through the cooperation of the clamping members 10 and the fixing member 20, thus preventing relative displacement between the two clamping members 10 and the battery during the test.

[0038] Optionally, the clamping member 10 is provided with a mounting protrusion 14 corresponding to the fixing member 20, and the fixing member 20 passes through the mounting protrusion 14. The mounting protrusion 14 provides a mounting position for the assembly of the fixing member 20 and the clamping member 10. In one specific embodiment of this application, there are multiple fixing members 20 and mounting protrusions 14, arranged around the periphery of the clamping member 10, and each mounting protrusion 14 is provided with at least one fixing member 20. With this arrangement, during the connection of the fixing member 20 with the two clamping members 10, contact and interference between the fixing member 20 and the battery under test when passing through the clamping space can be effectively avoided, thereby preventing damage to the battery.

[0039] Optionally, at least a portion of the mounting protrusions 14 are located at the corners of the clamping member 10, and at least another portion are located on the sides of the clamping member 10. In one specific embodiment of this application, two mounting protrusions 14 are correspondingly provided at each corner of the clamping member 10, and the protrusion directions of the two mounting protrusions 14 located at the same corner are perpendicular to each other. Furthermore, when the clamping frame 12 of the clamping member 10 in this embodiment is a rectangular frame, the number of fixing members 20 is 12. This ensures that the multiple fixing members 20 can more comprehensively fix the two clamping members 10, thereby ensuring the stability of the test fixture.

[0040] Furthermore, in order to ensure the flatness of the clamping member 10 in this application, the protrusion direction of the mounting protrusion 14 can be set along the length direction or the width direction of the clamping member 10.

[0041] Of course, in order to make the clamping member 10 in this application a frame structure, the clamping member 10 can also be set as a fence-like structure composed of multiple horizontal plates and multiple vertical plates. In this case, fasteners 20 can be set at both ends of the horizontal plates and both ends of the vertical plates respectively.

[0042] Optionally, the sum of the opening areas of all the clearance openings 11 of the same clamping member 10 is greater than or equal to 60% of the area of ​​the clamping surface. Of course, in this application, the area of ​​the clearance opening 11 can be adaptively adjusted according to actual design requirements.

[0043] As can be seen from the above description, the embodiments of this utility model achieve the following technical effects:

[0044] The test fixture in this application adopts a frame structure with corresponding structural strength and rigidity. The frame structure of the fixture restrains the four edges, the middle of the transverse direction, and the middle of the longitudinal direction of the test battery, which can suppress the expansion during the thermal runaway process of the battery without affecting the battery's pressure relief and normal venting. At the same time, the heat insulation layer can reduce the heat transfer to the fixture after the battery generates heat, preventing the temperature rise from slowing down and thus making it difficult to reach the thermal runaway critical temperature.

[0045] In the description of this utility model, it should be understood that the directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description. Unless otherwise stated, these directional terms 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 on the scope of protection of this utility model. The directional terms "inner" and "outer" refer to the inner and outer contours of each component itself.

[0046] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0047] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be construed as limiting the scope of protection of this utility model.

[0048] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A test fixture, characterized by, The test fixture comprises: at least two oppositely arranged clamping pieces (10), the two clamping pieces (10) having a clamping space therebetween, and the clamping piece (10) having an avoiding opening (11) penetrating the clamping piece (10) along the thickness direction of the clamping piece (10) so as to communicate the clamping space with the avoiding opening (11); a heat insulation layer, the surface of the side of the two clamping pieces (10) close to each other being a clamping surface, and the heat insulation layer being arranged on the clamping surface.

2. The test fixture of claim 1, wherein, The clamping piece (10) comprises: a clamping frame (12) having a hollow region; a partition (13) arranged on the clamping frame (12) to divide the hollow region into a plurality of avoiding openings (11).

3. The test fixture of claim 1, wherein, The test fixture further comprises a fixing piece (20) penetrating the two clamping pieces (10) respectively.

4. The test fixture of claim 3, wherein, The clamping piece (10) is provided with a mounting protrusion (14) corresponding to the fixing piece (20), and the fixing piece (20) penetrates the mounting protrusion (14).

5. The test fixture of claim 4, wherein, Both the fixing piece (20) and the mounting protrusion (14) are a plurality of, the plurality of mounting protrusions (14) are arranged around the periphery of the clamping piece (10), and at least one fixing piece (20) is arranged on each mounting protrusion (14).

6. The test fixture of claim 5, wherein, At least a part of the plurality of mounting protrusions (14) is arranged at the corner of the clamping piece (10), and at least another part of the mounting protrusions (14) is arranged on the side edge of the clamping piece (10).

7. The test fixture of claim 6, wherein, Two mounting protrusions (14) are arranged at each corner of the clamping piece (10) correspondingly, and the protruding directions of the two mounting protrusions (14) at the same corner are perpendicular to each other.

8. The test fixture of any one of claims 1 to 7, wherein, The clamping piece (10) has a plurality of avoiding openings (11), and the plurality of avoiding openings (11) of the two clamping pieces (10) are arranged oppositely one by one.

9. The test fixture of claim 8, wherein, The sum of the opening areas of all the avoiding openings (11) of the same clamping piece (10) is greater than or equal to 60% of the area of the clamping surface.

10. The test fixture of any one of claims 1 to 7, wherein, The clamping piece (10) is made of a metal material.

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