Three-point bending test tool

Abstract

The utility model discloses a three-point bending test tool, and the tool comprises a pressing seat assembly which comprises a pressing seat and a positioning seat, the positioning seat is fixedly connected to the lower part of the pressing seat, the positioning seat and the pressing seat are arranged at an interval, and the interval between the positioning seat and the pressing seat is larger than the thickness of a sample wafer so as to form a space for the sample wafer to pass through; the two supporting seat assemblies are symmetrically arranged on the two sides of the width direction of the positioning seat, each supporting seat assembly comprises a supporting seat, a fixing groove matched with a sample piece is formed in the position, corresponding to the positioning seat, of each supporting seat, and the bottom face of each fixing groove and the top face of the positioning seat are located on the same horizontal plane; and the sample piece is erected on the positioning seat, and the two end parts of the sample piece are fixed in the fixing grooves. The sample can be stably fixed for testing, so that the accuracy and the reliability of a sample testing result are ensured, the testing efficiency is improved, the testing cost is reduced, and the testing reliability of the cycle performance of the lithium ion battery is improved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of lithium battery testing devices, and in particular to a three-point bending test tool. BACKGROUND

[0002] Lithium ion batteries are widely used in electronic devices, energy storage devices, new energy vehicles and other fields due to their advantages such as large capacity and long discharge time. Before being put into use, the battery pieces of the lithium ion batteries need to be subjected to three-point bending tests to simulate the stress conditions under actual working conditions and evaluate the bending resistance thereof. In the conventional three-point bending test, the battery piece is directly arranged on the test tool, and the battery piece is not fixed. During the test, the external force applied is likely to cause the position of the battery piece to deviate or even cause the battery piece to fall off the test tool, resulting in inaccurate test results of the battery piece and affecting the normal use of the lithium ion battery.

[0003] To solve the problem, a three-point bending test device is disclosed in Chinese Patent CN117147331A, which comprises a pressure head mechanism, a pressure head pre-positioning mechanism, a test sample fixing mechanism and a supporting mechanism. The test sample fixing mechanism comprises a fixed guide rail, a moving sliding block and test sample fixing pieces. The bottom of the fixed guide rail is fixed to the top of the supporting mechanism through a threaded rod. Two moving sliding blocks are provided, and the two moving sliding blocks are in sliding connection with the fixed guide rail. Two groups of test sample fixing pieces are provided, and each group comprises two test sample fixing pieces. The two groups of test sample fixing pieces are respectively slidably arranged on the top of the two moving sliding blocks. The pressure head pre-positioning mechanism comprises two symmetrically arranged pre-positioning blocks and a fixed connecting plate arranged on one side of the pre-positioning blocks. The two pre-positioning blocks are in abutment and fixed, and a pre-positioning groove is formed at the middle position. The two pre-positioning blocks are respectively slidably arranged on the two groups of test sample fixing pieces. In this way, the three-point bending test device can determine and fix the position of the test sample through the test sample fixing mechanism, and pre-position the pressure head through the pressure head pre-positioning mechanism, so as to ensure the accuracy of the test and improve the test efficiency.

[0004] However, the above-mentioned test device still has the following defects: first, the pressure head pre-positioning mechanism needs to be installed before the test. When the pressure head mechanism is lowered into the pre-positioning groove of the pressure head pre-positioning mechanism and the bottom of the pressure head contacts the surface of the pre-positioning groove, the pressure head mechanism is controlled to stop descending and the pressure head pre-positioning mechanism is disassembled and removed, so that the three-point bending test can be continued. The test device not only has a complex operation, but also is likely to contact the surrounding pressure head, test sample fixing piece and other structures when the pressure head pre-positioning mechanism is disassembled, which causes the positioning to deviate and affects the test accuracy. Second, the test sample fixing pieces are slidably arranged on the top of the moving sliding block. When the test sample is subjected to the three-point bending test by the pressure head, the external force applied by the pressure head is likely to be transmitted to the test sample fixing piece through the test sample, causing the test sample fixing piece to slide and deviate, so that the position of the test sample deviates and affects the accuracy of the test result of the test sample. UTILITY MODEL CONTENT

[0005] To solve the above-mentioned defects in the prior art, the purpose of the present application is to provide a three-point bending test tool, which can stably fix the sample for testing, to ensure the accuracy and reliability of the sample test results, thereby improving the test efficiency, reducing the test cost, and improving the reliability of the lithium ion battery cycle performance test.

[0006] The technical scheme provided according to the purpose of the present application is as follows:

[0007] A three-point bending test tool, comprising:

[0008] The pressing seat assembly comprises a pressing seat and a positioning seat, the positioning seat is fixedly connected below the pressing seat, a space is provided between the positioning seat and the pressing seat, and the space between the two is greater than the thickness of the sample to form a space for the sample to pass through.

[0009] The two support seat assemblies are symmetrically arranged on both sides of the positioning seat in the width direction, and the support seat assembly comprises a support seat.

[0010] As a preferred embodiment, in the present application, the bottom end face of the pressing seat is covered with an elastic pad, and the distance between the elastic pad and the positioning seat is greater than the thickness of the sample.

[0011] As a preferred embodiment, in the present application, the bottom end face side of the pressing seat and / or the top end face side of the positioning seat is correspondingly provided with a chamfer structure.

[0012] As a preferred embodiment, in the present application, the top of the pressing seat is fixedly connected with a connector, and the connector is used to connect the driving part of the test tool.

[0013] As a preferred embodiment, in the present application, the pressing seat is a T-shaped structure, and the connector is fixed at the top center of the pressing seat.

[0014] As a preferred embodiment, in the present application, the support seat comprises an upper support seat and a lower support seat fixedly connected, and the fixing groove is formed between the upper support seat and the lower support seat.

[0015] As a preferred embodiment, in the present application, a rubber pad is arranged between the upper support seat and the lower support seat, and the rubber pad is symmetrically arranged on the side of the fixing groove.

[0016] As a preferred embodiment, in the present application, the support seat assembly further comprises a sliding rail, the support seat is slidingly arranged on the sliding rail, and the support seat is positioned by a positioning member.

[0017] As a preferred implementation, in the application, the bottom of the support seat is provided with a sliding block which is slidingly arranged in the sliding rail.

[0018] As a preferred implementation, in the application, the positioning member comprises a positioning bolt and a positioning nut, the positioning bolt penetrates the support seat and the sliding rail and is positioned by the positioning nut.

[0019] The three-point bending test tool provided by the application has the following technical effects:

[0020] By forming a space for the sample to pass between the positioning seat and the pressing seat, and by opening a fixing groove in the support seat which is adapted to the sample, when preparing for the three-point bending test of the sample, the middle part of the sample is placed on the positioning seat, and the two end parts of the sample are fixed in the fixing groove. In this way, when the pressing seat exerts force downward on the sample, the sample is stably fixed via the fixing groove, and the corresponding arrangement of the pressing seat and the positioning seat can enable the downward force of the pressing seat to be accurately exerted on the sample, and when the pressing seat exerts force downward on the sample, the positioning seat moves downward synchronously with the pressing seat to separate the positioning seat from the sample, without the need to disassemble the positioning seat. Not only is the structure simple and convenient to operate, but also the positioning of each component is not offset during the test, thereby ensuring the accuracy and reliability of the test results of the sample, improving the test efficiency of the sample, reducing the test cost, and improving the reliability of the cycle performance test of the lithium ion battery. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is a front view of the three-point bending test tool of the application;

[0022] Figure 2 It is a structural schematic view of the support seat assembly of the application;

[0023] Figure 3 It is an exploded view of the support seat assembly of the application;

[0024] Figure 4 It is a structural schematic view of the support seat assembly of the application from another perspective;

[0025] Figure 5 It is a structural schematic view of the pressing seat assembly of the application;

[0026] Figure 6 It is an exploded view of the pressing seat assembly of the application.

[0027] REFERENCE SIGNS:

[0028] 1, pressing seat assembly; 11, pressing seat; 12, positioning seat; 13, elastic pad; 14, joint; 2, support seat assembly; 21, support seat; 211, upper support seat; 212, lower support seat; 22, fixing groove; 23, rubber pad; 24, sliding block; 25, positioning bolt; 26, positioning nut; 3, screw. DETAILED DESCRIPTION

[0029] In order to better understand and implement, the technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application.

[0030] In the description of the present application, it should be noted that the orientations or positional relationships indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and are not intended to indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terminology used in the specification of the present application is only for the purpose of describing specific embodiments and is not intended to limit the present application.

[0032] Referring to Figure 1 , Figure 2 and Figure 5 , the present application provides a three-point bending test tooling, which comprises a pressure seat assembly 1 and two support seat assemblies 2. The pressure seat assembly 1 comprises a pressure seat 11 and a positioning seat 12, the positioning seat 12 is fixedly connected below the pressure seat 11, the positioning seat 12 and the pressure seat 11 are spaced apart, and the spacing between them is greater than the thickness of the sample to form a space for the sample to pass through. The two support seat assemblies 2 are symmetrically arranged on both sides of the width direction of the positioning seat 12, and the support seat assembly 2 comprises a support seat 21, the support seat 21 is provided with a fixed groove 22 corresponding to the positioning seat 12, the bottom surface of the fixed groove 22 and the top surface of the positioning seat 12 are on the same horizontal plane, so that the sample is placed on the positioning seat 12 and the two ends of the sample are fixed in the fixed groove 22.

[0033] Wherein, the width direction refers to the direction shown in Figure 1 , the length direction and the thickness direction refer to the direction shown in Figure 2 , and all directions related to components in the present application are based on this. On this basis, the pressure seat 11 and the positioning seat 12 are spaced apart in the thickness direction, and are fixedly connected by a screw 3, so as to form a space for the sample to pass through between the pressure seat 11, the positioning seat 12 and the screw 3, the thickness of the space is greater than the thickness of the sample, and the length of the space is greater than the length of the sample, so that the sample can freely pass through the space and be placed on the positioning seat 12, and the sample in the space will not bear extrusion force other than the force applied by the pressure seat 11, so as to ensure the accuracy of the sample test.

[0034] The pressing seat 11 is used to apply force to the sample piece to test the bending resistance of the sample piece during the three-point bending test of the sample piece. In order to ensure the accuracy of the test, the sample piece needs to be fixed to avoid deviation, and the pressing seat 11 needs to accurately apply force to the sample piece. Therefore, the positioning seat 12 is used to carry the middle part of the sample piece when the sample piece is prepared for testing, and the two support seats 21 are oppositely arranged on both sides of the positioning seat 12 in the width direction to carry the two end parts of the sample piece. The two support seats 21 oppositely arranged have fixing grooves 22, the fixing grooves 22 face the positioning seat 12, and the bottom surface of the fixing grooves 22 is on the same horizontal plane as the top surface of the positioning seat 12, which can ensure that the sample piece is placed stably. The length of the fixing groove 22 is adapted to the length of the sample piece, and the thickness of the fixing groove 22 is adapted to the thickness of the sample piece, so that the two end parts of the sample piece can be fixed by the two fixing grooves 22, so that the sample piece is fixed as a whole and stably. The pressing seat 11 and the positioning seat 12 are arranged in correspondence with each other and are fixedly connected by the screw 3, which can ensure that the pressing seat 11 and the positioning seat 12 move downward synchronously and the moving axes coincide when the pressing seat assembly 1 moves downward, so that the pressing seat 11 can accurately apply force to the middle part of the sample piece.

[0035] It should be noted that the distance between the pressing seat 11 and the positioning seat 12 is determined by the thickness of the sample piece and the size of the force required to be applied to the sample piece. The distance can be adjusted for different test situations.

[0036] In this way, the space for the sample piece to pass through is formed between the positioning seat 12 and the pressing seat 11, and the fixing groove 22 adapted to the sample piece is formed in the support seat 21, so that when the sample piece is prepared for three-point bending test, the middle part of the sample piece is placed on the positioning seat 12, and the two end parts of the sample piece are fixed in the fixing groove 22. In this way, when the pressing seat 11 applies force to the sample piece downward, the sample piece is stably fixed by the fixing groove 22, and the corresponding arrangement of the pressing seat 11 and the positioning seat 12 can accurately apply the downward force of the pressing seat 11 to the sample piece. When the pressing seat 11 applies force to the sample piece downward, the positioning seat 12 moves downward synchronously with the pressing seat 11 to separate the positioning seat 12 from the sample piece, without the need to disassemble the positioning seat 12. Not only is the structure simple and convenient to operate, but also the positioning of each part will not be deviated during the test, so as to ensure the accuracy and reliability of the test result of the sample piece, thereby improving the test efficiency of the sample piece, reducing the test cost, and improving the reliability of the lithium ion battery cycle performance test.

[0037] Referring to Figure 5 and Figure 6 , the top of the pressing seat 11 is fixedly connected with the joint 14, and the joint 14 is used to connect the driving part of the test tool. In this way, during the three-point bending test, the driving part can drive the joint 14 to move downward, thereby driving the pressing seat 11 and the positioning seat 12 to move downward synchronously to apply force to the middle part of the sample piece, so as to test the bending resistance of the sample piece.

[0038] The pressing seat 11 is in T-shaped structure, and the joint 14 is fixed at the top center of the pressing seat 11. The lower part of the pressing seat 11 is relatively narrow in the width direction to facilitate the application of force to the sample for testing its bending resistance, and the top of the pressing seat 11 is relatively wide to form a large surface and is fixedly connected with the joint 14 through the screw 3, which can improve the stability of the connection between the joint 14 and the pressing seat 11. In this way, when the three-point bending test is performed on the sample, the pressing seat 11 can stably and accurately apply force to the sample, thereby improving the accuracy of the test results of the sample.

[0039] In addition, the bottom end surface side of the pressing seat 11 and / or the top end surface side of the positioning seat 12 are correspondingly provided with chamfer structures. The chamfer structures are arranged on both sides of the width direction of the bottom end surface of the pressing seat 11 and both sides of the width direction of the top end surface of the positioning seat 12, which not only can reduce the wear of the corresponding end surfaces of the pressing seat 11 and the positioning seat 12 during the test, prolong the service life, but also can avoid damaging the sample due to burrs and the like during the test, and at the same time, the chamfer structure can reduce the impact resistance, reduce the energy consumption and cost during the test, and improve the test effect.

[0040] Further, the bottom end surface of the pressing seat 1 is covered with an elastic pad 13, and the distance between the elastic pad 13 and the positioning seat 12 is greater than the thickness of the sample. The elastic pad 13 is a rubber pad, and the setting of the elastic pad 13 has a buffering effect, which can avoid damaging the sample due to factors such as burrs in addition to the application of force during the test, and ensures the integrity of the sample.

[0041] As for the support seat 21, referring to Figure 2 and Figure 3 , the support seat 21 includes an upper support seat 211 and a lower support seat 212 fixedly connected, and a fixed groove 22 is formed between the upper support seat 211 and the lower support seat 212. The upper support seat 211 and the lower support seat 212 are fixedly connected through the screw 3, and the fixed groove 22 can be formed by corresponding recesses on the bottom of the upper support seat 211 and the top of the lower support seat 212, or as shown in Figure 3 , the recesses are formed on the top of the lower support seat 212. The depth of the fixed groove 22 in the thickness direction is adapted to the thickness of the sample, and the length of the fixed groove 22 is adapted to the length of the sample. During the preparation stage before the test, the two support seats 21 are symmetrically arranged on both sides of the width direction of the positioning seat 12, so that the both ends of the sample in the width direction are fixed in the fixed groove 22, thereby ensuring that the middle part of the sample is arranged on the positioning seat 12.

[0042] and Figure 3The top of the lower support base 212 is provided with a groove to form a fixing groove 22. The depth of the fixing groove 22 in the thickness direction can be adjusted according to the thickness of the sample. The upper support base 211 and the lower support base 212 are provided with rubber pads 23, which are symmetrically arranged on the sides of the fixing groove 22. The rubber pad 23 is a rubber pad, which not only has a buffering effect, but also can adjust the depth of the fixing groove 22 in the thickness direction through the rubber pad 23. For example, the compression degree of the rubber pad 23 can be adjusted by the degree of screwing of the screw 3, or the rubber pad 23 with different thicknesses is replaced, etc. to realize the adjustment of the depth of the fixing groove 22 in the thickness direction.

[0043] Since the widths of different samples are different, the distances between the two support bases 21 and the positioning base 12 are also different. Before testing, the positions of the support bases 21 need to be adjusted according to the width of the sample. The support base assembly further comprises a sliding rail (not shown in the figure), and the support base 21 is slidingly arranged on the sliding rail, and the support base 21 is positioned by a positioning member.

[0044] Referring to Figures 2-4 , the bottom of the support base 21 is provided with a sliding block 24, which is slidingly arranged in the sliding rail. The support base 21 is placed on the sliding rail, and the bottom surface of the support base 21 is in contact with the top surface of the sliding rail to ensure the stability of the placement of the support base 21. In this state, the sliding block 24 is located in the sliding rail to push the support base 21 to slide along the sliding rail by the sliding block 24, thereby guiding the position adjustment of the support base 21 to ensure the accuracy of the fixed position of the sample.

[0045] After the support base 21 is slid into position, the positioning member fixes the support base 21 on the sliding rail. The positioning member comprises a positioning bolt 25 and a positioning nut 26, the positioning bolt 25 penetrates the support base 21 and the sliding rail, and is positioned by the positioning nut 26.

[0046] The support base 21 is of L-shaped structure, comprising a vertical section and a horizontal section, and the horizontal section is located at one side of the bottom of the vertical section. In the first structure, the positioning bolt 25 penetrates the horizontal section and the sliding rail downward in turn, and the positioning bolt 25 is positioned by the positioning nut 26 after extending out of the bottom of the sliding rail. In this structure, the sliding rail is provided with a through hole for the penetration of the positioning bolt 25. In the second structure, the positioning bolt 25 penetrates the horizontal section downward and extends into the sliding rail, and is positioned by the positioning nut 26. In this structure, the positioning nut 26 is clamped in the sliding rail. The first structure is preferred, which is not only convenient to install, but also has high installation stability.

[0047] The technical means disclosed in the application scheme is not limited to the technical means disclosed in the above embodiments, but also includes the technical solutions composed of any combination of the above technical features. It should be noted that for ordinary skilled persons in the art, without departing from the principles of the application, a number of improvements and refinements can be made, which are also considered within the protection scope of the application.

Claims

1. A three-point bending test fixture, characterized in that, include: The pressure seat assembly (1) includes a pressure seat (11) and a positioning seat (12). The positioning seat (12) is fixedly connected to the lower part of the pressure seat (11). The positioning seat (12) and the pressure seat (11) are spaced apart, and the distance between them is greater than the thickness of the sample to form a space for the sample to pass through. Two support base assemblies (2) are symmetrically arranged on both sides of the positioning base (12) in the width direction. Each support base assembly (2) includes a support base (21). The support base (21) has a fixing groove (22) corresponding to the positioning base (12) to fit the sample. The bottom surface of the fixing groove (22) is on the same horizontal plane as the top surface of the positioning base (12) so that the sample is placed on the positioning base (12) and the two ends of the sample are fixed in the fixing groove (22).

2. The three-point bending test fixture according to claim 1, characterized in that: The bottom end of the pressure seat (11) is covered with an elastic pad (13), and the distance between the elastic pad (13) and the positioning seat (12) is greater than the thickness of the sample.

3. The three-point bending test fixture according to claim 1 or 2, characterized in that: The bottom side of the pressure seat (11) and / or the top side of the positioning seat (12) are respectively provided with chamfered structures.

4. The three-point bending test fixture according to claim 1, characterized in that: The top of the pressure base (11) is fixedly connected to a connector (14), which is used to connect the drive part of the test fixture.

5. The three-point bending test fixture according to claim 4, characterized in that: The pressure seat (11) has a T-shaped structure, and the connector (14) is fixed at the top center of the pressure seat (11).

6. The three-point bending test fixture according to claim 1, characterized in that: The support base (21) includes an upper support base (211) and a lower support base (212) that are fixedly connected, and the fixing groove (22) is formed between the upper support base (211) and the lower support base (212).

7. The three-point bending test fixture according to claim 6, characterized in that: A rubber pad (23) is provided between the upper support (211) and the lower support (212), and the rubber pad (23) is symmetrically arranged on the side of the fixing groove (22).

8. The three-point bending test fixture according to claim 1, 6, or 7, characterized in that: The support assembly also includes a slide rail, the support (21) is slidably disposed on the slide rail, and the support (21) is positioned by a positioning element.

9. The three-point bending test fixture according to claim 8, characterized in that: The bottom of the support base (21) is provided with a slider (24), which is slidably disposed in the slide rail.

10. The three-point bending test fixture according to claim 8, characterized in that: The positioning component includes a positioning bolt (25) and a positioning nut (26). The positioning bolt (25) passes through and connects the support base (21) and the slide rail, and is positioned by the positioning nut (26).

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