Novel battery cell test tool
By designing a new type of battery cell testing fixture, which uses a screw to control the movement of the clamping plate to apply pre-tightening force, the problem of unevenness in battery cell expansion force testing was solved, achieving accuracy and uniform force distribution in battery cell expansion force detection and improving the accuracy of test results.
Patent Information
- Application Number
- CN202423319238.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-31
- Publication Date
- 2026-02-13
- Estimated Expiration
- 2034-12-31
AI Technical Summary
Existing cell expansion force testing methods lack precision, and uneven stress distribution across different parts of the cell affects the accuracy of test results and cell performance evaluation.
A novel battery cell testing fixture is designed. It applies an initial preload by controlling the movement of the clamping plate through a screw, and combines an expansion force sensing module for accurate detection to ensure that the force is uniformly applied to all parts of the battery cell.
It achieves precise control of cell expansion force testing, and the test state is closer to the real working condition after PACK, which improves the accuracy of test results and the uniformity of cell stress.
Smart Images
Figure CN223911024U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of battery production and manufacturing, and particularly relates to a novel battery cell test tool. BACKGROUND
[0002] Today, with the rapid development of new energy power battery technology, the new energy pure electric vehicle industry has ushered in an unprecedented development opportunity, realizing a leap from theoretical exploration to market popularization. The rapid development of this field not only promotes the green transformation of the automobile industry, but also puts forward more stringent technical requirements for the single battery cell which constitutes the core component of the electric vehicle. In order to meet the needs of new energy vehicles for endurance mileage, safety performance and service life, the performance optimization of single battery cell has become one of the focuses of technical research and development.
[0003] From single battery cell to the final battery pack (PACK) integration, the use conditions of the battery cell have undergone significant changes. During the PACK assembly process, the battery cell usually needs to undergo a certain degree of extrusion to ensure the close arrangement and effective thermal management between the battery cells, so as to realize efficient energy output and storage. In addition, the cyclic working conditions of the battery cell in actual use need to be considered in the PACK design stage, especially the swelling force caused by internal chemical reaction and physical deformation of the battery cell in the later stage of the cycle, which poses a challenge to the rigidity and structural stability of the battery cell and the entire battery pack. Therefore, the accurate evaluation and control of the swelling force of the battery cell have become a key link to ensure the performance and safety of the battery pack.
[0004] At present, for the test method of the swelling force of the battery cell, the industry generally adopts the method of fixing the swelling force sensing module on the special fixture through screws, and combining with the external swelling force detection module to monitor the swelling of the battery cell under simulated cyclic working conditions. However, this test scheme has exposed some problems in actual operation. First, the adjustment of the swelling force lacks accuracy, and it is difficult to achieve fine control of the swelling behavior of the battery cell; second, the existing tool fixture relies on manual rotation of multiple screws to achieve when applying the initial pre-tightening force, and this operation method is difficult to ensure that the battery cell is uniformly stressed at each part when subjected to the initial pre-tightening force, thereby affecting the accuracy of the test results and the actual performance evaluation of the battery cell. CONTENT OF THE UTILITY MODEL
[0005] The embodiment of the present application provides a novel battery cell test tool, which sets the battery cell between the second clamping plate and the base, controls the movement of the second clamping plate to the base direction through the screw connected with the second clamping plate, so as to apply the initial pre-tightening force to the battery cell, and moves the first clamping plate downward to fix the swelling force sensing module through the screw connected with the first clamping plate, so as to detect the swelling force of the battery cell, thereby solving the problems that the existing tool cannot accurately control and the stress of each part of the battery cell is uneven.
[0006] In one aspect, the embodiment of the present application provides a novel battery cell test tool, which comprises a base, a top plate parallel to the base, and a fixed connection between the top plate and the base;
[0007] A first clamping plate and a second clamping plate are arranged between the top plate and the base, the first clamping plate is above the second clamping plate, and an expansion force sensing module is arranged between the first clamping plate and the second clamping plate;
[0008] Two screw holes perpendicular to the base are formed in the top plate, and a screw rod is threadedly installed in each screw hole, one of the screw rods is rotationally connected with the first clamping plate, and the other screw rod is rotationally connected with the second clamping plate.
[0009] In one possible implementation, the two screw rods are a first screw rod and a second screw rod, the first screw rod is rotationally connected with the first clamping plate, and the second screw rod is rotationally connected with the second clamping plate.
[0010] A first through hole perpendicular to the top plate is formed in the first clamping plate, and the second screw rod passes through the first through hole.
[0011] In one possible implementation, two side plates perpendicular to the top plate are fixedly installed on the two sides of the top plate, one side of the second clamping plate is in contact with the inner side of one of the side plates, and the other side of the second clamping plate is in contact with the inner side of the other side plate.
[0012] In one possible implementation, a strip-shaped plate is fixedly installed on the bottom of the outer side of the side plate, the strip-shaped plate is perpendicular to the side plate, the strip-shaped plate is parallel to the base, and the strip-shaped plate is detachably connected with the base.
[0013] In one possible implementation, a groove is formed in the bottom surface of the first clamping plate and / or the top surface of the second clamping plate, and the expansion force sensing module is embedded in the groove.
[0014] In one possible implementation, a handle is fixedly installed at the upper end of each of the two screw rods.
[0015] In one possible implementation, a horizontal bubble is fixedly installed on the top surface of the second clamping plate, a second through hole is formed in each of the first clamping plate and the top plate, and the horizontal bubble is vertically corresponding to the two second through holes.
[0016] In one possible implementation, a strip-shaped groove is formed in the outer periphery of the screw rod in the axial direction, the strip-shaped groove penetrates the screw rod in the radial direction, two bolts pass through the strip-shaped groove, and a nut is threadedly installed on each of the bolts, the two bolts are located on the upper and lower sides of the top plate.
[0017] In a feasible implementation, the base is fixedly provided with a sliding guide rail, and a scale is fixedly provided on a sliding seat of the sliding guide rail and perpendicular to the top surface of the base.
[0018] In another aspect, the embodiments of the present application provide a novel battery cell test tool, which comprises first, second, third and fourth clamping members arranged in sequence from top to bottom, the first, second, third and fourth clamping members are parallel to each other, the first clamping member is fixedly connected with the fourth clamping member;
[0019] An expansion force sensing module is arranged between the second clamping member and the third clamping member;
[0020] Two displacement adjusting members are arranged on the first clamping member, the displacement adjusting direction of each displacement adjusting member is perpendicular to the bottom surface of the first clamping member, one displacement adjusting member is connected with the second clamping member, and the other displacement adjusting member is connected with the third clamping member;
[0021] A horizontal bubble is fixedly arranged on the third clamping member.
[0022] The novel battery cell test tool provided by the embodiments of the present application sets the battery cell between the second clamping plate and the base, controls the second clamping plate to move towards the base through the screw rod connected with the second clamping plate, so as to exert an initial pre-tightening force on the battery cell, the battery cell is in contact with the second clamping plate and the base at the same time, and is subjected to uniform force, the first clamping plate is moved downward to fix the expansion force sensing module through the screw rod connected with the first clamping plate, so that the expansion force of the battery cell can be detected, the operation is simple, and the initial expansion force of the battery cell can be accurately controlled through the number of rotations of the screw rod, so that the test state of the battery cell is closer to the real working condition after PACK, and the problems of inaccurate control and uneven force on each part of the battery cell in the prior art are solved. BRIEF DESCRIPTION OF DRAWINGS
[0023] Figure 1 FIG. 1 is a structural schematic diagram of a novel battery cell test tool provided by an embodiment of the present application;
[0024] Figure 2 FIG. 2 is a top zoomed-in view of FIG. 1. Figure 1
[0025] Legend of the drawings:
[0026] 1-base; 2-top plate; 3-first clamping plate; 4-second clamping plate; 5-expansion force sensing module; 6-screw hole; 7-screw rod; 8-side plate; 9-strip plate; 10-groove; 11-handle; 12-horizontal bubble; 13-second through hole; 14-strip hole; 15-bolt; 16-sliding guide rail; 17-scale. DETAILED DESCRIPTION
[0027] In order to make the technical personnel in the technical field better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor should be within the scope of protection of the present application.
[0028] Figure 1 is a structural schematic view of a new battery cell test tool provided by an embodiment of the present application; Figure 2 is Figure 1 is a top view zoomed in view of Figure 1 and Figure 2 It is shown that the present application provides a new battery cell test tool, which comprises a base 1, a top plate 2 parallel to the base 1 is arranged above the base 1, and the top plate 2 is fixedly connected with the base 1;
[0029] A first clamping plate 3 and a second clamping plate 4 are arranged between the top plate 2 and the base 1, the first clamping plate 3 is located above the second clamping plate 4, and an expansion force sensing module 5 is arranged between the first clamping plate 3 and the second clamping plate 4;
[0030] Two screw holes 6 perpendicular to the base 1 are formed in the top plate 2, and a screw rod 7 is threadedly installed in each screw hole 6, one of the screw rods 7 is rotatably connected with the first clamping plate 3, and the other screw rod 7 is rotatably connected with the second clamping plate 4.
[0031] It should be noted that the first clamping plate 3 and the second clamping plate 4 are parallel to the top plate 2, and the expansion force sensing module 5 is arranged at the center position of the first clamping plate 3 and the second clamping plate 4. The two screw holes 6 are symmetrically distributed in the length direction of the top plate 2, and the upper ends of the screw rods 7 all protrude out of the corresponding screw holes 6.
[0032] In some specific examples, the first clamping plate 3, the second clamping plate 4 and the screw rod 7 are rotatably connected through bearings. The expansion force sensing module 5 can be selected from a pressure sensor or a thin film sensor.
[0033] In the above embodiment, the battery cell is arranged between the second clamping plate 4 and the base 1, the initial pre-tightening force is applied to the battery cell by controlling the movement of the second clamping plate 4 to the base 1 through the screw rod 7 connected with the second clamping plate 4, the battery cell is in contact with the second clamping plate 4 and the base 1 at the same time, and the stress is uniform, which can avoid the cycle failure of the battery cell caused by uneven stress in the later stage of the test cycle, the first clamping plate 3 is moved downward to fix the expansion force sensing module 5 through the screw rod 7 connected with the first clamping plate 3, and the expansion force detection of the battery cell can be performed, which is simple and convenient to operate, and the initial expansion force of the battery cell can be accurately controlled through the number of rotations of the screw rod 7, so that the test state of the battery cell is closer to the real working condition after PACK, and the problems of inaccurate control and uneven stress of each part of the battery cell in the existing tooling are solved.
[0034] In some examples, the two screw rods 7 are a first screw rod and a second screw rod respectively, the first screw rod is rotationally connected with the first clamping plate 3, and the second screw rod is rotationally connected with the second clamping plate 4.
[0035] A first through hole perpendicular to the top plate 2 is formed in the first clamping plate 3, and the second screw rod passes through the first through hole.
[0036] It is easy to understand that, in order to ensure the smooth connection of the second screw rod and the second clamping plate 4, the first through hole is formed in the first clamping plate 3, so that the second screw rod passes through the first through hole and is connected with the second clamping plate 4.
[0037] In the above embodiment, after the second screw rod passes through the first through hole, the second screw rod can also limit the first clamping plate 3, so as to prevent the first clamping plate 3 from rotating with the first screw rod, thereby ensuring that the first clamping plate 3 can effectively move vertically with each rotation of the first screw rod.
[0038] In other examples, the length of the first clamping plate 3 can also be reduced, and the first clamping plate 3 can cover the expansion force sensing module 5 without passing through the second screw rod.
[0039] In some examples, the two sides of the top plate 2 are respectively fixedly installed with side plates 8 perpendicular thereto, one side of the second clamping plate 4 is in contact with the inner side surface of one of the side plates 8, and the other side of the second clamping plate 4 is in contact with the inner side surface of the other side plate 8.
[0040] It is easy to understand that the top plate 2 and the side plate 8 can be fixedly connected by welding or bonding, or can be fixedly connected by screws.
[0041] In the above embodiment, the two sides of the second clamping plate 4 are in contact with the inner side surfaces of the two side plates 8 at the same time, and when the user rotates the second screw rod, the second clamping plate 4 cannot rotate with the second screw rod, thereby ensuring that the second clamping plate 4 can effectively move vertically with each rotation of the second screw rod.
[0042] In some examples, the outer side surface of the side plate 8 is fixedly installed with a strip-shaped plate 9, which is perpendicular to the side plate 8 and parallel to the base 1, and the strip-shaped plate 9 is detachably connected with the base 1.
[0043] It should be noted that the strip-shaped plate 9 and the base 1 are fixedly connected by screws or other detachable means. Taking screws as an example, each strip-shaped plate 9 is connected with the base 1 by at least two screws.
[0044] In the above embodiment, the bottom surface of the strip-shaped plate 9 and the bottom surface of the side plate 8 are in close contact with the top surface of the base 1, thereby ensuring the stability of the connection between the top plate 2 and the base 1. The strip-shaped plate 9 and the base 1 are fixedly connected by screws or other detachable means, which facilitates the installation and disassembly of the tooling. This connection mode not only ensures the firmness between the strip-shaped plate 9 and the base 1, but also effectively transmits the force and stability between the structures, thereby improving the overall load-carrying capacity and service life of the entire tooling.
[0045] In some examples, the bottom surface of the first clamping plate 3 and / or the top surface of the second clamping plate 4 is provided with a recess 10, and the expansion force sensing module 5 is embedded in the recess 10.
[0046] In order to further optimize the structure of the test tooling and improve its test accuracy and stability, the embodiment provides a recess 10 on the bottom surface of the first clamping plate 3 and / or the top surface of the second clamping plate 4. The shape, size and depth of these recesses 10 are matched with the expansion force sensing module 5 to ensure that the expansion force sensing module 5 can be perfectly accommodated and fixed.
[0047] In other examples, the expansion force sensing module 5 can be further connected with the recess 10 by screws to prevent displacement of the expansion force sensing module 5 in the horizontal direction.
[0048] The expansion force sensing module 5, as a core component of the test tooling, its accuracy and sensitivity are crucial to the reliability of the test results. By embedding the expansion force sensing module 5 in the recess 10 of the first clamping plate 3 or the second clamping plate 4, the interference of external factors on the sensing module can be effectively reduced, and the measurement accuracy can be improved. At the same time, this embedded design can also enhance the connection strength between the sensing module and the clamping plate, preventing the sensing module from loosening or being damaged due to uneven stress or vibration during the test process.
[0049] In addition, the design of the recess 10 also takes into account the easy installation and disassembly of the expansion force sensing module 5. When it is necessary to replace or maintain the expansion force sensing module 5, the operator can easily take it out of or install it into the recess 10 without the need to disassemble the entire test tooling. This not only improves the work efficiency, but also reduces the operation difficulty and cost.
[0050] In summary, in the above embodiment, by designing the recess 10 on the first clamping plate 3 and / or the second clamping plate 4 and embedding the expansion force sensing module 5, the embodiment not only improves the testing accuracy and stability of the test tool, but also optimizes the installation and maintenance method of the expansion force sensing module 5, providing a more reliable and efficient solution for the expansion force test of the battery cell.
[0051] In some examples, the upper ends of the two screw rods 7 are fixedly installed with handles 11.
[0052] It is easy to understand that, as shown in Figure 2 It is easy to understand that, as shown in
[0053] In the above embodiment, the operator can easily and comfortably hold the handle 11 and perform the rotating operation. The presence of the handle 11 not only makes the rotating operation of the screw rod 7 more labor-saving and smooth, but also significantly improves the work efficiency. The operator only needs to hold the handle 11 and apply an appropriate amount of force to achieve accurate rotation of the screw rod 7, thereby adjusting the distance between the first clamping plate 3 and the second clamping plate 4 to achieve the purpose of clamping or releasing the battery cell.
[0054] In some examples, the top surface of the second clamping plate 4 is fixedly installed with a horizontal bubble 12, and the first clamping plate 3 and the top plate 2 are both provided with a second through hole 13, and the horizontal bubble 12 is vertically corresponding to the two second through holes 13.
[0055] It is easy to understand that, as a commonly used measuring tool, the horizontal bubble 12 can accurately indicate whether the tool or object is in a horizontal state, thereby helping the operator to quickly and intuitively judge and adjust the levelness of the tool.
[0056] In the above embodiment, in order to further improve the accuracy and reliability of the battery cell test tool of the embodiment, the first clamping plate 3 and the top plate 2 are both provided with a second through hole 13 vertically corresponding to the horizontal bubble 12. These two second through holes 13 not only provide an accurate positioning reference for the installation of the horizontal bubble 12, but also ensure that the horizontal bubble 12 can clearly display the current level of the tool when observed. When the operator observes the horizontal bubble 12 through the second through hole 13, any slight tilt or unevenness can be quickly discovered, and the tool can be adjusted accordingly to ensure the accuracy and stability of the test.
[0057] It is worth mentioning that two horizontal bubbles 12 can be symmetrically arranged on the top surface of the second clamping plate 4, and corresponding second through holes 13 can be provided on the first clamping plate 3 and the top plate 2. They can be used to determine whether the force applied by the second clamping plate 4 to the battery cell is uniform. By rotating the two screw rods 7 to make the horizontal bubble 12 in the middle position, the battery cell as a whole can be in a state of balanced force.
[0058] In some examples, the outer periphery of the screw rod 7 is provided with a strip-shaped slot 14, the strip-shaped slot 14 extends radially through the screw rod 7, two bolts 15 pass through the strip-shaped slot 14, and nuts are respectively screwed on the bolts 15, and the bolts 15 are respectively located on the upper and lower sides of the top plate 2.
[0059] It is easy to understand that the head of the bolt 15 and the nut are respectively located on the two sides of the screw rod 7, each screw rod 7 corresponds to two bolts 15 and two nuts, and the diameter of the head of the bolt 15 and the diameter of the nut are both greater than the width of the strip-shaped slot 14, that is, the strip-shaped slot 14 can only pass through the threaded part of the bolt 15.
[0060] In the above embodiment, after the screw rod 7 is adjusted, the corresponding two nuts are tightened, and the outer periphery of the bolt 15 and the nut is in contact with the top surface or the bottom surface of the top plate 2, when the battery cell expands, the bolt 15 and the nut can resist the force generated by the expansion of the battery cell, prevent the screw rod 7 from moving axially, and at the same time, the thread on the screw rod 7 is protected to some extent, which can reduce the possibility of damage.
[0061] In some examples, the base 1 is fixedly provided with a sliding guide rail 16, a sliding seat of the sliding guide rail 16 is fixedly provided with a scale 17, and the scale 17 is perpendicular to the top surface of the base 1.
[0062] In the above embodiment, the sliding guide rail 16 is transversely arranged, and the scale 17 can move transversely along the sliding guide rail 16, so as to measure the thickness of the battery cell at each transverse position, thereby monitoring the thickness change of the battery cell in different test periods.
[0063] On the other hand, the embodiment of the present application also provides a novel battery cell test tool, which comprises first, second, third and fourth clamping members arranged in sequence from top to bottom, the first, second, third and fourth clamping members are parallel to each other, and the first clamping member and the fourth clamping member are fixedly connected.
[0064] An expansion force sensing module 5 is arranged between the second clamping member and the third clamping member.
[0065] Two displacement adjusting members are arranged on the first clamping member, the displacement adjusting direction of the displacement adjusting members is perpendicular to the bottom surface of the first clamping member, one of the displacement adjusting members is connected with the second clamping member, and the other displacement adjusting member is connected with the third clamping member.
[0066] A horizontal bubble 12 is fixedly arranged on the third clamping member.
[0067] In the above embodiment, the battery cell is arranged between the third clamping member and the fourth clamping member, the second clamping member and the third clamping member are moved in the direction perpendicular to the first clamping member by the displacement adjusting member, the third clamping member is controlled to move towards the fourth clamping member by the displacement adjusting member, so that the initial pre-tightening force is applied to the battery cell, the battery cell is in contact with the third clamping member and the fourth clamping member at the same time, and the stress is uniform, which can avoid the cycle failure of the battery cell caused by uneven stress in the later stage of the test cycle, the second clamping member is moved downward by the displacement adjusting member to fix the expansion force sensing module 5, so that the expansion force detection of the battery cell can be performed, the operation is simple, and the initial expansion force of the battery cell can be adjusted by a single displacement adjusting member, without considering the cooperative matching between multiple screws as in the prior art, so that the initial expansion force of the battery cell can be more accurately controlled, the test state of the battery cell is closer to the real working condition after PACK, and the problems of inaccurate control and uneven stress of each part of the battery cell in the prior art are solved. The horizontal bubble 12 can be used to determine whether the force applied to the battery cell by the third clamping member is uniform, the horizontal bubble 12 on the third clamping member is in the middle position by the displacement adjusting member, so that the whole battery cell is in a balanced stress state.
[0068] It is easy to understand that, on the basis of the several embodiments provided in the present application, the skilled in the art can combine, split, recombine, etc. to obtain other embodiments, and these embodiments do not exceed the protection scope of the present application.
[0069] The above specific embodiments further explain the purpose, technical solutions and beneficial effects of the embodiments of the present application. It should be understood that the above is only a specific embodiment of the present application, and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made on the basis of the technical solutions of the embodiments of the present application should be included in the protection scope of the embodiments of the present application.
Claims
1. A novel cell testing fixture, characterized by, It includes base (1), the top of base (1) is equipped with top plate (2) parallel with it, top plate (2) is fixedly connected with base (1); First clamping plate (3) and second clamping plate (4) are arranged between top plate (2) and base (1), first clamping plate (3) is located above second clamping plate (4), expansion force sensing module (5) is arranged between first clamping plate (3) and second clamping plate (4); Two vertical screw holes (6) of base (1) are formed on top plate (2), one screw rod (7) is respectively screwed in screw hole (6), one of screw rod (7) is rotatably connected with first clamping plate (3), the other screw rod (7) is rotatably connected with second clamping plate (4).
2. The novel cell testing fixture of claim 1, wherein, Two screw rods (7) are first screw rod and second screw rod, first screw rod is rotatably connected with first clamping plate (3), second screw rod is rotatably connected with second clamping plate (4); First through hole perpendicular to top plate (2) is formed on first clamping plate (3), second screw rod passes through first through hole.
3. The novel cell testing tool of claim 1 or 2, wherein, Two sides of top plate (2) are respectively fixedly installed with vertical side plate (8), one side of second clamping plate (4) is in contact with the inner side of one of side plate (8), the other side of second clamping plate (4) is in contact with the inner side of the other side plate (8).
4. The novel cell testing fixture of claim 3, wherein, The outer side of the side plate (8) is fixedly installed with a strip plate (9), the strip plate (9) is perpendicular to the side plate (8), and the strip plate (9) is parallel to the base (1), the strip plate (9) is detachably connected with the base (1).
5. The novel cell testing tool of claim 1 or 2, wherein, The bottom surface of the first clamping plate (3) and / or the top surface of the second clamping plate (4) is provided with a recess (10), and the expansion force sensing module (5) is embedded in the recess (10).
6. The novel cell testing tool of claim 1 or 2, wherein, The upper end of the two screw rods (7) is fixedly installed with a handle (11).
7. The novel cell testing tool of claim 1 or 2, wherein, The top surface of the second clamping plate (4) is fixedly installed with a horizontal bubble (12), and the first clamping plate (3) and the top plate (2) are provided with a second through hole (13), and the horizontal bubble (12) is vertically corresponding to the two second through holes (13).
8. The novel cell testing tool of claim 1 or 2, wherein, The outer periphery of the screw rod (7) is provided with a strip groove (14) in the axial direction, the strip groove (14) penetrates the screw rod (7) in the radial direction, two bolts (15) pass through the strip groove (14), and nuts are respectively screwed on the bolts (15), and the bolts (15) are respectively located on the upper and lower sides of the top plate (2).
9. The novel cell testing tool of claim 1 or 2, wherein, The base (1) is fixedly installed with a sliding guide rail (16), and a scale (17) is fixedly installed on the sliding seat of the sliding guide rail (16), and the scale (17) is perpendicular to the top surface of the base (1).
10. A novel cell testing fixture, characterized by, It includes first clamping piece, second clamping piece, third clamping piece and fourth clamping piece arranged in sequence from top to bottom, first clamping piece, second clamping piece, third clamping piece and fourth clamping piece are parallel to each other, first clamping piece and fourth clamping piece are fixedly connected; Expansion force sensing module (5) is arranged between second clamping piece and third clamping piece; Two displacement adjusting members are arranged on the first clamping member, and the displacement adjusting directions of the displacement adjusting members are perpendicular to the bottom surface of the first clamping member, wherein one of the displacement adjusting members is connected with the second clamping member, and the other displacement adjusting member is connected with the third clamping member. A horizontal bubble (12) is fixedly installed on the third clamping member.