A needle puncture testing machine for lithium battery detection

Abstract

The application discloses a kind of lithium battery detection with needle test machine, it is related to lithium battery needle detection technical field, including: test machine main body, test bin, puncture needle, test bin is opened in test machine main body, puncture needle is fixedly connected in test bin, still include: first component, second component, first component and second component are on same vertical plane;Through the clamping of magnetic clamping ring, the perfusion of magnetic fluid in column rod, the magnetic attraction of magnetic fluid in column rod can be effectively guaranteed that the position of column rod does not change when puncture needle is operated to fixed lithium battery;Meanwhile, the meshing design of gear ring and gear further improves the stability when puncture needle is impacted to lithium battery, effectively ensures that each puncture experiment is carried out according to the expected angle of penetration, reduces the existence of interference factors caused by the instability of lithium battery during puncture operation, further improves the accuracy of test data.

Description

Technical Field

[0001] This invention relates to the field of lithium battery needle penetration testing technology, specifically to a needle penetration testing machine for lithium battery testing. Background Technology

[0002] Existing technologies, such as the Chinese patent entitled "A Needle Penetration Testing Machine" with publication number CN213149191U, mention that "on the one hand, the driving component 11 drives the lead screw 13 to rotate through the gear transmission assembly 12. The lead screw 13 has the advantages of high precision and high transmission efficiency, so it can accurately drive the sliding component 2 to reciprocate, thereby driving the needle 7 to move, and then allowing the needle 7 to pass through the needle penetration hole 3140, so as to perform needle penetration testing on the battery module 6 to be tested. The operation is simple and convenient, which is conducive to the standardization and normalization of needle penetration testing. On the other hand, the battery mounting device 3 is further used to fix the battery module 6 to be tested, so as to avoid the movement of the battery module affecting the test results."

[0003] 1. The equipment described in the aforementioned patent documents and existing technologies has the following problems in actual use:

[0004] The aforementioned application documents and existing technologies only fix the lithium battery under test in a fixed orientation during the nail penetration test. This fixed orientation design has significant limitations. On the one hand, in reality, lithium batteries are subjected to punctures from different directions under various complex environments. For example, in actual use, lithium batteries are punctured by sharp objects from multiple directions. Existing fixed-orientation puncture detection methods cannot effectively simulate these multi-directional puncture situations, leading to a significant deviation between the test results and actual conditions. Specifically, fixed-orientation puncture makes the test results too idealized and cannot accurately reflect the lithium battery under real multi-directional puncture conditions. In terms of safety performance in various scenarios, the impact of punctures from different directions on lithium batteries varies significantly. Horizontal punctures cause lateral displacement of the electrode materials inside the battery, increasing the risk of internal short circuits; vertical punctures directly damage the positive and negative electrode separators, triggering more violent reactions; and punctures at an angle cause complex damage to multiple battery structures simultaneously. Existing testing methods cannot comprehensively assess the risks posed by punctures from different directions, leading to incorrect assessments of lithium battery safety. This results in some lithium batteries with potential safety hazards in actual use being put on the market, posing potential dangers to users.

[0005] 2. Although the aforementioned patent mentions fixing the battery to be tested for needle penetration, the fixing method described in the document is only applicable to clamping and fixing regular square batteries, and is not suitable for clamping cylindrical or irregularly shaped lithium battery packs. This limits the application of the test. On the one hand, during the needle penetration process, due to insufficient tightness of the clamping device, the battery may fall off the clamping device when it loosens. If the battery is in a heated or unstable state at this time, the impact of the fall will cause further damage to the internal structure of the battery, thereby triggering a stronger reaction, damaging surrounding equipment, causing fires, and resulting in personal injury and property damage. On the other hand, loosening of the clamping device will change the stress on the battery during the needle penetration process. This will cause the pressure sensor to be unable to accurately measure the actual pressure during the needle penetration, and the temperature sensor will also be unable to accurately monitor the temperature change of the battery due to the change in the battery's position, thus making the test data unreliable and unable to provide an accurate basis for the battery safety assessment.

[0006] Therefore, we propose a needle penetration tester for lithium battery testing to solve the above problems. Summary of the Invention

[0007] In view of this, the technical problem to be solved by the present invention is to provide a needle penetration tester for lithium battery testing, so as to solve the problems existing in the prior art.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a needle penetration tester for lithium battery testing, comprising: a tester body, a test chamber, and a puncture needle, wherein the test chamber is formed on the tester body and the puncture needle is fixedly connected inside the test chamber, and further comprising: a first component and a second component, wherein the first component and the second component are on the same vertical plane;

[0009] The first component is used to simulate the multi-directional impact test of a lithium battery when it is actually subjected to impact and puncture.

[0010] The second component is used to fasten square, cylindrical, and irregularly shaped lithium batteries.

[0011] As an improvement, the first component includes four electrically operated telescopic rods fixedly connected inside the test chamber. The electric telescopic rods are equidistantly arranged inside the test chamber, and a drive motor is fixedly connected to the center of the test chamber. The shaft end of the drive motor is laterally fixedly connected to the cylindrical column.

[0012] As an improvement, a column rod is movably inserted into the cylinder, a magnetic snap ring is snapped onto the cylinder, and both ends of the column rod are fixedly connected to support members.

[0013] As an improvement, the upper ends of the two support members are fixedly connected to a fixing plate, and the upper surface of the fixing plate is magnetically fixed to a magnetic fixing plate assembly.

[0014] As an improvement, an annular groove ring is fixedly connected to the upper end of the electric telescopic rod, a gear ring is fixedly connected to the inner groove of the annular groove ring, a connecting rod is fixedly connected to the column rod, and a gear is rotatably connected to the end of the connecting rod away from the column rod.

[0015] As an improvement, the second component includes an injection pipe fixedly connected to the column rod, and the support has a vertical cavity with a sliding plate slidably connected within the vertical cavity.

[0016] As an improvement, the fixed plate has a working cavity, a spring is fixedly connected to the inner wall of the working cavity, an auxiliary plate is fixedly connected to the end of the spring away from the inner wall of the working cavity, a fixed rod is fixedly connected to the auxiliary plate, and a cylindrical cavity is formed inside the fixed rod.

[0017] As an improvement, the cylinder is provided with slots at equal intervals, which are compatible with magnetic snap rings.

[0018] As an improvement, the column is a hollow structure, and magnetic fluid is injected into its interior through an injection pipe.

[0019] As an improvement, the support is provided with an injection port, through which solution can be injected into the vertical cavity.

[0020] Compared with the prior art, the present invention provides a needle penetration tester for lithium battery testing, which has the following advantages:

[0021] 1. This application, through the design of the first component, can effectively simulate the state of lithium batteries subjected to punctures from different directions under various complex environments in reality. Unlike the prior art and the designs in the aforementioned applications that only fix the lithium battery under test without adjusting the puncture direction, this application improves the obvious limitations of testing. It effectively reduces the deviation between the test results and the actual situation, and can effectively reflect the safety performance of lithium batteries under real multi-directional puncture scenarios. This application provides a relatively comprehensive evaluation of situations such as the risk of internal short circuits caused by lateral displacement of the internal electrode materials, damage to the positive and negative electrode isolation layers, and complex damage to multiple battery structures caused by oblique punctures. From a research and development perspective, this application can assist in analyzing the weak points of lithium batteries under different puncture angles, thereby enabling targeted structural design and material selection to improve the safety and reliability of lithium batteries, and is conducive to the optimization and improvement of lithium battery structures.

[0022] 2. This application, through the design of the second component, enables the quick and easy securing of lithium batteries of different shapes. Unlike the aforementioned applications which only fix regular-shaped batteries, this application is applicable to clamping square, cylindrical, and irregularly shaped lithium battery packs. This design effectively prevents batteries from loosening and falling out of the clamping device due to insufficient clamping strength. If the battery is in a heated or unstable state when it falls out, the impact will further damage the internal structure of the battery, triggering a stronger reaction that could damage equipment, cause fires, and result in personal injury and property damage. Simultaneously, this application's fixing design avoids the impact of lithium batteries falling, ensuring the normal operation of all sensors in the device, guaranteeing the reliability of test data, and providing accurate evidence for battery safety assessment.

[0023] 3. This application utilizes a magnetic snap ring and the injection of magnetic fluid into the rod. During the puncture operation on a fixed lithium battery, the magnetic snap ring's magnetic attraction to the magnetic fluid effectively ensures the rod's position remains unchanged. Simultaneously, the meshing design of the gear ring and gear further enhances the stability of the puncture device during impact puncture of the lithium battery, effectively ensuring that each puncture experiment is performed strictly according to the intended insertion angle. This reduces interference caused by the instability of the lithium battery during puncture, further improving the accuracy of the test data.

[0024] 4. In this application, by using an aqueous solution, water is injected from the injection port on the support member into the support member, vertical channels, and cylindrical cavities, thereby indirectly enabling the second component to effectively adapt to lithium batteries of different shapes. The aqueous solution injected into the cylindrical cavity can effectively reduce the thermal expansion of the fixing rod that secures the lithium battery when the battery is punctured and damaged, thus improving the service life of the component. Furthermore, since water is compressible, even if the fixing rod is deformed by heat, it can still ensure the secure fastening of the lithium battery. The above design differs from the application documents and prior art in which the service life of the fastening components decreases and the fastening effect is compromised due to thermal expansion and contraction caused by lithium battery damage.

[0025] 5. Through the design and use of the electric telescopic rod and drive motor in this application, the lithium battery can still move in angle and direction even during the puncture test. In this way, while the puncture direction is close to reality, it further simulates real-world scenarios, such as when a vehicle's brakes fail and it crashes into a guardrail or obstacle, making it difficult to determine the position of the vehicle's battery, thereby further improving the completeness of the test. Attached Figure Description

[0026] Figure 1 This is a structural diagram showing the relative positions of the main structure of the invention and the main body of the testing machine.

[0027] Figure 2This is a three-dimensional schematic diagram of the main structure of the present invention;

[0028] Figure 3 This is a structural diagram of the present invention when the fixing plate is in a horizontal state;

[0029] Figure 4 For the present invention Figure 3 Enlarged view of the local structure at point A in the middle;

[0030] Figure 5 This is a structural diagram of the fixed plate after the angle and orientation of the fixed plate are adjusted according to the present invention;

[0031] Figure 6 This is a disassembly diagram of the cylindrical column, column rod, and magnetic snap ring of the present invention;

[0032] Figure 7 These are structural diagrams of the vertical cavity and sliding plate of the present invention;

[0033] Figure 8 These are cross-sectional structural diagrams of the cylindrical column and support components of the present invention.

[0034] Figure 9 For the present invention Figure 8 Enlarged view of the local structure at point B;

[0035] Figure 10 This is a front view of the main structure of the present invention.

[0036] In the picture:

[0037] 1. Main body of the testing machine; 2. Testing chamber; 3. Puncture needle;

[0038] 4. First component; 401. Electric telescopic rod; 402. Drive motor; 403. Cylindrical column; 404. Column rod; 405. Magnetic snap ring; 406. Support component; 407. Fixing plate; 408. Magnetic fixing plate assembly; 409. Ring groove ring; 410. Gear ring; 411. Connecting rod; 412. Gear;

[0039] 5. Second component; 501. Injection tube; 502. Vertical cavity; 503. Sliding plate; 504. Working cavity; 505. Spring body; 506. Auxiliary plate; 507. Fixing rod; 508. Cylindrical cavity. Detailed Implementation

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0042] Example: Please refer to Figures 1 to 7 , Figure 10 As shown:

[0043] To address the problems mentioned in the technical solutions, this application provides a needle penetration tester for lithium battery testing, comprising: a tester body 1, a test chamber 2, and a puncture needle 3. The test chamber 2 is located on the tester body 1, and the puncture needle 3 is fixedly connected inside the test chamber 2. The tester body 2 also includes: a first component 4 and a second component 5, wherein the first component 4 and the second component 5 are located on the same vertical plane.

[0044] The first component 4 is used to simulate the multi-directional impact test of a lithium battery under actual impact and puncture. The first component 4 includes four electrically operated telescopic rods 401 fixedly connected inside the test chamber 2. The electrically operated telescopic rods 401 are equidistantly arranged inside the test chamber 2. A drive motor 402 is fixedly connected to the middle of the test chamber 2. The shaft end of the drive motor 402 is laterally fixedly connected to a cylindrical column 403. A column rod 404 is movably inserted into the cylindrical column 403. A magnetic clip is attached to the cylindrical column 403. The connecting ring 405 and the column rod 404 are both fixedly connected to the support member 406. The upper ends of the two support members 406 are fixedly connected to the fixing plate 407. The upper surface of the fixing plate 407 is magnetically fixedly connected to the magnetic fixing plate group 408. The upper end of the electric telescopic rod 401 is fixedly connected to the annular groove ring 409. The inner groove of the annular groove ring 409 is fixedly connected to the gear ring 410. The column rod 404 is fixedly connected to the connecting rod 404. The end of the connecting rod 411 away from the column rod 404 is rotatably connected to the gear 412.

[0045] in:

[0046] The first component 4 is mainly used for simulating the multi-directional impact test of lithium batteries when they are actually subjected to impact and puncture.

[0047] The cylindrical column 403 has slots at equal intervals, which are compatible with the magnetic snap ring 405.

[0048] The column 404 has a hollow structure, and magnetic fluid is injected into its interior through the injection pipe 501.

[0049] The magnetic retaining ring 405 is mainly used in conjunction with the magnetic fluid injected inside the column rod 404 to reduce the movement of the column rod 404 when the puncture needle 3 impacts the lithium battery on the second component 5, thereby improving the stability of the overall testing work.

[0050] The magnetic fixing plate assembly 408 is composed of spring body 505, auxiliary plate 506, fixing rod 507, and cylindrical cavity 508, and is connected to an external inflation pipe. The fastening operation is the same as that of the second assembly 5.

[0051] Gear 412 meshes with gear ring 410.

[0052] A further embodiment: Please refer to Figures 7 to 10 As shown:

[0053] The second component 5 is used to fasten the square, cylindrical and irregularly shaped lithium batteries. The second component 5 includes an injection tube 501 fixedly connected to the column rod 404, a vertical cavity 502 opened in the support member 406, a sliding plate 503 slidably connected in the vertical cavity 502, a working cavity 504 opened in the fixed plate member 407, a spring body 505 fixedly connected in the inner wall of the working cavity 504, an auxiliary piece 506 fixedly connected at the end of the spring body 505 away from the inner wall of the working cavity 504, a fixing rod 507 fixedly connected on the auxiliary piece 506, and a cylindrical cavity 508 opened in the fixing rod 507.

[0054] in:

[0055] The second component 5 is mainly used for fastening square, cylindrical, and irregularly shaped lithium batteries.

[0056] The injection pipe 501 is a conduit for injecting magnetic fluid into the column rod 404.

[0057] The support member 406 is provided with an injection port, through which a solution, such as water, can be injected into the vertical cavity 502.

[0058] The sliding plate 503 is slidably adapted to the vertical cavity 502.

[0059] The vertical cavity 502, the working cavity 504, and the cylindrical cavity 508 are connected.

[0060] The spring 505 is mainly used to pull the auxiliary plate 506 to reset the fixing rod 507.

[0061] The auxiliary piece 506 slides and adapts to the working cavity 504.

[0062] When the aqueous solution is injected into the cylindrical cavity 508, during the needle penetration test of the lithium battery, when the lithium battery is damaged and heats up, the aqueous solution in the cylindrical cavity 508 will reduce the probability of the cylindrical cavity 508 expanding due to heat, thereby reducing the reduction in the service life of the cylindrical cavity 508 caused by changes in thermal expansion.

[0063] The working principle of all the content in the above embodiments is as follows:

[0064] In the initial state: support 406 and connecting rod 411 are in a vertical state; spring 505 is not stretched.

[0065] It should be noted that the angle and orientation of the fixing plate 407 need to be adjusted according to the testing requirements of the tester. At the same time, the number of magnetic fixing plates 408 and magnetic clip rings 405 on the cylinder 403 can be increased or decreased according to the shape and size of the lithium battery to be tested.

[0066] The following is the working process of the first component 4:

[0067] When adjusting the position of the lithium battery under test fixed on the fixing plate 407, the adjustment is mainly done by adjusting the angle and orientation of the fixing plate 407; specifically:

[0068] Angle Adjustment: First, start the electric telescopic rod 401. As the electric telescopic rod 401 extends, it will move the annular groove ring 409 at its top upward. During the upward movement of the annular groove ring 409, the gear 412 in the annular groove ring 409 will not rotate while meshing with the teeth of the gear ring 410, but the connection point between the gear 412 and the connecting rod 411 will rotate. That is, during the upward movement of the annular groove ring 409, the connecting rod 411 will rotate around the rotational connection point with the gear 412 as the axis of rotation. Since it is known that the connecting rod 411 is fixedly connected to the column rod 404, and the column rod 404 is indirectly fixedly connected to the fixed plate 407 through the support member 406, when the connecting rod 411 deflects, the fixed plate 407 on the support member 406 will also deflect. That is, the fixed plate 407, which was originally in a horizontal state, will become tilted. Thus, the angle adjustment of the fixed plate 407 is completed.

[0069] Orientation adjustment: Start the drive motor 402. Since the column rod 404 is known to be sleeved in the cylinder 403 fixedly connected to the upper end of the drive motor 402, when the drive motor 402 rotates, the column rod 404 sleeved in the cylinder 403 will rotate accordingly, thereby completing the orientation adjustment. During this process, the gear 412 on the connecting rod 411 fixedly connected to the column rod 404 will move on the gear ring 410 in the annular groove ring 409, thereby providing stability for the orientation adjustment of the column rod 404.

[0070] Furthermore, the design of the first component 4 in this application can effectively simulate the state of lithium batteries subjected to punctures from different directions under various complex environments in reality. Unlike the existing technology and the design in the aforementioned application documents that only fixes the lithium battery under test and cannot adjust the puncture direction, this application improves the obvious testing limitations. It effectively reduces the deviation between the test results and the actual situation and can effectively reflect the safety performance of lithium batteries in real multi-directional puncture scenarios. This application has made a relatively comprehensive assessment of the risks of lateral displacement of the internal electrode materials, which increases the risk of internal short circuits, damage to the positive and negative electrode isolation layers, and complex damage to multiple structures of the battery caused by oblique punctures. From a research and development perspective, this application can help analyze the weak points of lithium batteries under different puncture angles, thereby enabling targeted structural design and material selection to improve the safety and reliability of lithium batteries and to optimize and improve the structure of lithium batteries.

[0071] Furthermore, through the design and use of the electric telescopic rod 401 and the drive motor 402 in this application, the lithium battery can still move in angle and direction even during the puncture test. In this way, based on the puncture direction being close to reality, it further simulates real-world scenarios, such as when a vehicle's brakes fail and it crashes into a guardrail or obstacle, making it difficult to determine the position of the vehicle's battery, thereby further improving the completeness of the detection.

[0072] Furthermore, this application, through the locking mechanism of the magnetic retaining ring 405 and the injection of magnetic fluid into the rod 404, effectively ensures that the position of the rod 404 does not change when the puncture needle 3 punctures the fixed lithium battery. This is achieved by the magnetic attraction of the magnetic fluid in the rod 404 through the magnetic retaining ring 405. At the same time, the meshing design of the toothed ring 410 and the gear 412 further improves the stability of the puncture needle 3 when puncturing the lithium battery, effectively ensuring that each puncture experiment is strictly performed according to the expected puncture angle, reducing the interference caused by the instability of the lithium battery during the puncture operation, and further improving the accuracy of the test data.

[0073] Please refer to the above work process. Figures 1 to 7 , Figure 10 .

[0074] The following is the working process of the second component 5:

[0075] During use, with the assistance of an external water pump, aqueous solution can be added to the vertical cavity 502 and the working cavity 504 connected to the vertical cavity 502 through the filling port on the support 406. At this time, the cylindrical cavity 508 opened on the fixing rod 507 will also be filled with aqueous solution. Furthermore, as the aqueous solution is added, the fixing rod 507 will gradually move closer to the lithium battery to be tested. At this time, the spring 505 will be stretched. Furthermore, under the continuous injection of aqueous solution, the fixing rods 507 located at different positions on the fixing plate 407 will adaptively approach and finally abut and fasten the lithium battery to be tested, thereby completing the lithium battery fixing work before the puncture test.

[0076] Furthermore, this application, through the design of the second component 5, enables the quick and easy securing of lithium batteries of different shapes. Unlike the limitations of the aforementioned applications, which can only secure regular-shaped batteries, this application is applicable to clamping square, cylindrical, and irregularly shaped lithium battery packs. This design effectively prevents batteries from loosening and falling out of the clamping device due to insufficient clamping strength. If the battery is in a heated or unstable state when it falls out, the impact will further damage the internal structure of the battery, triggering a stronger reaction that could damage equipment, cause fires, and result in personal injury and property damage. Simultaneously, the securing design of this application avoids the impact of lithium batteries falling out, ensuring the normal operation of all sensors in the device, guaranteeing the reliability of test data, and providing accurate evidence for battery safety assessment.

[0077] Furthermore, this application utilizes an aqueous solution to inject water into the support 406, the vertical cavity 502, and the cylindrical cavity 508 through the injection port on the support 406. This indirectly enables the second component 5 to effectively adapt to lithium batteries of different shapes. The aqueous solution injected into the cylindrical cavity 508 can effectively reduce the thermal expansion of the fixing rod 507 that secures the lithium battery when the battery is punctured and damaged, thus improving the service life of the component. Moreover, since water is compressible, even if the fixing rod 507 deforms due to heat, it can still ensure the secure fastening of the lithium battery. The above design differs from the application documents and prior art in which the service life of the fastening components decreases and the fastening effect is compromised due to thermal expansion and contraction caused by lithium battery damage.

[0078] Please refer to the above work process. Figures 7 to 10 .

[0079] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0080] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A needle penetration tester for lithium battery testing, comprising: The test machine body (1), test chamber (2), and puncture needle (3) are provided. The test chamber (2) is located on the test machine body (1), and the puncture needle (3) is fixedly connected inside the test chamber (2). The test machine body is characterized by further comprising: a first component (4) and a second component (5), the first component (4) and the second component (5) being on the same vertical plane; the first component (4) is used to simulate the multi-directional impact simulation test of a lithium battery when it is actually subjected to impact puncture; the first component (4) includes an electric telescopic rod (401) fixedly connected inside the test chamber (2), the electric telescopic rod (401) being provided with... Four electric telescopic rods (401) are equidistantly arranged inside the test chamber (2). A drive motor (402) is fixedly connected to the middle of the test chamber (2). The shaft end of the drive motor (402) is horizontally fixedly connected to the cylindrical column (403). A column rod (404) is movably inserted into the cylindrical column (403). A magnetic snap ring (405) is snapped onto the cylindrical column (403). Support members (406) are fixedly connected to both ends of the column rod (404). A fixing plate (407) is fixedly connected to the upper end of the two support members (406). A magnetically fixed plate (407) is magnetically attached to the upper surface of the fixing plate (407). A magnetic fixing plate assembly (408) is provided. An annular groove ring (409) is fixedly connected to the upper end of the electric telescopic rod (401). A gear ring (410) is fixedly connected in the inner groove of the annular groove ring (409). A connecting rod (411) is fixedly connected to the column rod (404). A gear (412) is rotatably connected to the end of the connecting rod (411) away from the column rod (404). The second component (5) is used to fasten the square, cylindrical and irregularly shaped lithium battery. The second component (5) includes an injection tube (501) fixedly connected to the column rod (404). A vertical support is provided in the support member (406). A sliding plate (503) is slidably connected to the vertical cavity (502). A working cavity (504) is opened in the fixed plate (407). A spring body (505) is fixedly connected to the inner wall of the working cavity (504). An auxiliary plate (506) is fixedly connected to one end of the spring body (505) away from the inner wall of the working cavity (504). A fixing rod (507) is fixedly connected to the auxiliary plate (506). A cylindrical cavity (508) is opened in the fixing rod (507). The column rod (404) is a hollow structure, and magnetic fluid is injected into its interior through an injection tube (501). The cylindrical column (403) is provided with slots at equal intervals, which are compatible with magnetic snap rings (405); the support member (406) is provided with an injection port.

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