Scribing device

By designing a ticking device including a base, fixture, support mechanism, clamp mechanism and tool, the problems of uneven engraving lines of the battery case are solved, efficient and accurate ticking lines are achieved, and disassembly efficiency and safety are improved.

CN223012070UActive Publication Date: 2025-06-24JIANGSU ZENIO NEW ENERGY BATTERY TECH CO LTD
View PDF 0 Cites 0 Cited by

Patent Information

Application Number
CN202421983684.7
Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
Filing Date
2024-08-15
Publication Date
2025-06-24
Estimated Expiration
2034-08-15

AI Technical Summary

Technical Problem

In the process of disassembly of the battery case, the markings are not straight and the depths are different, resulting in the shell being easily scratched, posing safety hazards and affecting work efficiency.

Method used

A ticking device is designed, including a base, a fixture, a support mechanism, a clamp mechanism and a tool. The fixture limits the position of the workpiece, supports the mechanism to suspend the tool, and the clamp mechanism provides abutment support to ensure tool stability and ticking accuracy.

Benefits of technology

It realizes the efficiency and accuracy of the battery case ticking, improves the subsequent disassembly efficiency, reduces safety hazards and operation difficulty, and enhances operation safety.

✦ Generated by Eureka AI based on patent content.

Smart Images

  • Figure CN223012070U_ABST
    Figure CN223012070U_ABST
Patent Text Reader

Abstract

The utility model relates to the technical field of workpiece scribing, and discloses a scribing device which comprises a base, a jig, a supporting mechanism, a clamping plate mechanism and a cutter. The tool is connected to the top of the base and used for limiting the position of a workpiece to be scribed, the supporting mechanism is connected with the base and the tool, the tool is supported by the supporting mechanism so as to be suspended above the tool, the tool and the supporting mechanism are in sliding connection in the first direction, and the tool and the supporting mechanism are in sliding connection in the second direction. The tool slides in the first direction and is used for scribing the outer surface of a to-be-scribed workpiece on the jig, and the clamping plate mechanism is arranged on the side opposite to the tool and used for abutting against the face, back on to the tool, of the to-be-scribed workpiece; the technical problems of how to improve the working efficiency of scribing the battery shell and how to improve the scribing accuracy are mainly solved.
Need to check novelty before this filing date? Find Prior Art

Description

Technical Field

[0001] The utility model relates to the technical field of workpiece line engraving, in particular to a line engraving device. Background Art

[0002] like Figure 1 As shown, the shell of the current battery is generally designed to include a shell 10 and a top cover 20, wherein the shell 10 is provided with a mounting groove for accommodating the battery cell, and the top cover 20 and the shell 10 are welded. After the top cover 20 and the shell 10 are welded, the notch of the mounting groove will be sealed, so that the battery cell is protected in the shell. At present, when the battery is subjected to destructive testing or when the internal battery cell needs to be recovered later, the shell needs to be disassembled. The current disassembly method is that the operator holds the battery with one hand and uses a metal knife to score with the other hand. The purpose of scoring is to form a score groove 30 on the surface of the shell to reduce the thickness of the shell. After scoring a circle, the operator uses pliers to apply force to the prism of the shell to cause the shell to crack an opening at the prism, and then gradually peels the shell into two parts along the score groove 30. During the above disassembly process, due to the size of the battery cell and the marking technique, the marking lines are often not straight and the depth of the marking lines is different. This will cause the shell to be easily scratched when the pliers are used to break the shell. When the shell is broken, it may even cause the battery cell to be punctured. In addition, the marking process may easily scratch the hands due to the technique. These factors will greatly affect the work efficiency and work safety of the dismantler. Utility Model Content

[0003] The utility model provides a marking device, which mainly solves the technical problem of how to improve the working efficiency of marking a battery shell and improve the accuracy of marking.

[0004] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0005] A marking device, comprising a base, a fixture, a supporting mechanism, a clamping plate mechanism and a cutter;

[0006] The jig is connected to the top of the base and is used to limit the position of the workpiece to be engraved. The supporting mechanism is respectively connected to the base and the tool. The tool is supported by the supporting mechanism to be suspended above the jig. The tool is connected to the supporting mechanism for sliding along a first direction. The tool slides along the first direction to engrave the outer surface of the workpiece to be engraved on the jig. The clamping plate mechanism is provided on the side opposite to the tool and is used for abutting against a side of the workpiece to be engraved that is away from the tool.

[0007] In one of the technical solutions, the scribing device further includes a sliding seat, the tool is connected to the sliding seat, the sliding seat is slidably connected to the support mechanism along the first direction, and the position of the tool relative to the sliding seat along the horizontal second direction is adjustable, wherein the first direction and the second direction are perpendicular to each other.

[0008] In one of the technical solutions, a waist-shaped hole is provided on the sliding seat, the waist-shaped hole extends in the second direction, and a bolt for fixing the tool to the sliding seat is inserted through the waist-shaped hole.

[0009] In one of the technical solutions, scale lines are provided on the top surface of the sliding seat, the scale lines are arranged at intervals along the second direction, and a benchmark is connected to the tool, and the benchmark extends to a position adjacent to the scale lines.

[0010] In one of the technical solutions, the support mechanism includes a support wall, a support rod and a guide rail table;

[0011] The support wall is fixedly connected to the base, the support rod is inserted through the support wall, the guide rail table is fixed to one end of the support rod, a guide rail is provided on the guide rail table, and the sliding seat is slidably connected to the guide rail table along the first direction by connecting the guide rail.

[0012] In one of the technical solutions, the support mechanism further includes a first nut and a second nut respectively threadedly connected to the support rod, the support rod penetrates outwards relative to the support wall, and the first nut and the second nut are respectively arranged on opposite sides of the support wall and are used to jointly clamp the support wall.

[0013] In one of the technical solutions, the clamping plate mechanism includes a support seat, a connecting rod and a clamping plate;

[0014] The support seat is fixedly connected to the base, the connecting rod is inserted through the support seat, the clamping plate is fixed to one end of the connecting rod, and the clamping plate is arranged on the side opposite to the tool and is used for the side of the workpiece to be scribed facing away from the tool to abut against.

[0015] In one of the technical solutions, the clamping plate mechanism further includes a third nut and a fourth nut respectively threadedly connected to the connecting rod, the connecting rod penetrates outwards relative to the support seat, and the third nut and the fourth nut are respectively arranged on opposite sides of the support seat and are used to jointly clamp the support seat.

[0016] In one of the technical solutions, a first limiting groove and a second limiting groove are provided in a downward concave manner at the top of the fixture, and both the first limiting groove and the second limiting groove are used to limit the position of the workpiece to be scribed.

[0017] In one of the technical solutions, the first limiting groove communicates with the second limiting groove, the extending direction of the first limiting groove points to the first direction, and the extending direction of the first limiting groove and the extending direction of the second limiting groove are perpendicular to each other, so that the first limiting groove and the second limiting groove jointly form a cross groove structure.

[0018] Compared with the prior art, the scribing device provided by the present utility model has at least the following beneficial effects:

[0019] Before operation, it is necessary to pre-place the workpiece to be scribed (such as a battery) on the jig and pre-adjust the positions of the tool and the clamping plate mechanism; during operation, the tool can be pushed to move relative to the support mechanism in the first direction, so as to scribe the outer surface of the workpiece to be scribed straight. When the workpiece to be scribed is being scribed by the tool, the side of the workpiece to be scribed facing away from the tool will be abutted against the clamping plate mechanism under the action of the tool, so as to improve the stability of the tool when scribing the workpiece and improve the accuracy of the scribing depth of the tool. The scribing device adopting this solution can quickly complete the scribing work of the battery shell, improve the scribing efficiency, thereby improving the subsequent disassembly efficiency of the battery. Moreover, the scribing device adopting this solution can also improve the scribing accuracy, solve the problems such as the scribing being uneven or the scribing depth being poor caused by manual operation errors in traditional manual work. Since this solution is beneficial to improving the scribing accuracy, it is not easy to scratch the internal battery cells or puncture the electrode sheets during the subsequent disassembly of the battery. At the same time, it also reduces the scribing difficulty of the operator and reduces the risk of scratching the hands, improving the safety of the subsequent battery disassembly process. Description of the Drawings

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0021] Figure 1 Structural schematic diagram of an existing battery with scribing on the outer surface provided for the background art;

[0022] Figure 2 Structural schematic diagram of a scribing device provided by an embodiment of the present application;

[0023] Figure 3 For Figure 2 Partial enlarged view of part A in

[0024] Figure 4 For Figure 3 Partial enlarged view of part B in

[0025] Reference numerals:

[0026] 1. Base; 2. Fixture; 21. First limiting groove; 22. Second limiting groove;

[0027] 3. Support mechanism; 31. Support wall; 32. Support rod; 33. Guide rail table; 34. Guide rail; 35. First nut; 36. Second nut;

[0028] 4. Clamping plate mechanism; 41. Support seat; 42. Connecting rod; 43. Clamping plate; 44. Third nut; 45. Fourth nut;

[0029] 5. Tool; 6. Battery; 7. Slide seat; 71. Waist-shaped hole; 72. Scale line; 73. Handle;

[0030] 8. Bolt; 9. Alignment rod; 10. Housing; 20. Top cover; 30. Grooved line. Detailed implementation manners

[0031] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application clearer and more understandable, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0032] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0033] It should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0034] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality" means two or more, unless otherwise specifically defined.

[0035] In order to make the objectives, technical solutions and advantages of the present utility model clearer and more understandable, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments.

[0036] Please refer to Figures 2 to 4 , an embodiment of the present utility model provides a scribing device, which mainly includes a base 1, a fixture 2, a support mechanism 3, a clamping plate mechanism 4 and a tool 5. Among them, the fixture 2 is fixed on the top of the base 1, and the fixture 2 is used to limit the position of the workpiece to be scribed. Preferably, the fixture 2 limits the position of the workpiece to be scribed by setting a limit groove on the top. In this embodiment, the workpiece to be scribed mainly takes the battery 6 as an example; among them, the support mechanism 3 is respectively connected to the base 1 and the tool 5, and the tool 5 is supported by the support mechanism 3 and thus suspended above the fixture 2. The tool 5 is slidably connected to the support mechanism 3 along the first direction (i.e., the X direction). The sliding of the tool 5 along the X direction is used to scribe the outer surface of the battery 6 located on the fixture 2. The cutting edge of the tool 5 is a sharp angle, and the angle of the cutting edge of the tool 5 is between 20° and 120°. The central axis of the cutting edge of the tool 5 is perpendicular to the outer surface of the battery 6, and the clamping plate mechanism 4 is arranged on the side opposite to the tool 5 and is used for the side of the battery 6 opposite to the tool 5 to abut.

[0037] Before operation, it is necessary to pre-place the battery 6 on the fixture 2 and pre-adjust the positions of the tool 5 and the clamping plate mechanism 4; during operation, the tool 5 can be pushed to move relative to the support mechanism 3 along the X direction, so that the outer surface of the battery 6 can be scribed straight. When the battery 6 is being scribed by the tool 5, the side of the battery 6 facing away from the tool 5 will be forced by the tool 5 to abut against the clamping plate mechanism 4, so as to improve the stability of the tool 5 when scribing the battery 6 and improve the accuracy of the scribing depth of the tool 5. The scribing device adopting this solution can quickly complete the scribing work on the outer shell of the battery 6, improve the scribing efficiency, thereby improving the subsequent disassembly efficiency of the battery 6. Moreover, the scribing device adopting this solution can also improve the scribing accuracy, solving problems such as unstraight scribing or poor scribing depth caused by manual operation errors in traditional manual work. Since this solution is beneficial to improving the scribing accuracy, it is not easy to scratch the internal battery core or pierce the electrode plate during the subsequent disassembly of the battery 6. At the same time, it also reduces the scribing difficulty of the operator and reduces the risk of scratching the human hand, improving the safety of the subsequent disassembly process of the battery 6.

[0038] In this embodiment, the scribing device further includes a slide base 7. The tool 5 is connected to the slide base 7. The slide base 7 is slidably connected to the support mechanism 3 in the X direction. The position of the tool 5 relative to the slide base 7 is adjustable in the horizontal second direction (i.e., the Y direction), where the X direction and the Y direction are perpendicular to each other. By providing the slide base 7, on the one hand, it is convenient to realize that the tool 5 can slide in the X direction. On the other hand, it is convenient to realize the function of fixing the tool 5, and it is also convenient to realize the purpose that the tool 5 can adjust its position in the Y direction. Designing the tool 5 to be adjustable in the Y direction enables the tool 5 to adjust the depth of scribing on the outer shell of the battery 6. Or, it can make the tool 5 compatible with the scribing operations of batteries 6 with different width dimensions, making the scribing device have the advantage of high compatibility. During operation, just operate the slide base 7 to move in the X direction, and the function of the tool 5 scribing on the outer surface of the battery 6 can be realized. For the convenience of operation, a handle 73 can be fixed on the top of the slide base 7.

[0039] In this embodiment, a waist-shaped hole 71 is provided on the slide base 7. The waist-shaped hole 71 extends in the Y direction. A bolt 8 is inserted through the waist-shaped hole 71. The bolt 8 also passes through the tool 5 while passing through the waist-shaped hole 71, so that the tool 5 can be fixed on the slide base 7. By sliding the bolt 8 along the waist-shaped hole 71 in the Y direction, the position of the tool 5 in the Y direction can be adjusted, and further the depth of scribing of the tool 5 on the battery 6 can be adjusted. This design can realize the function that the tool 5 is adjustable in the Y direction, and has the advantages of simple structure and low cost.

[0040] In this embodiment, scale lines 72 are provided on the top surface of the slide base 7. The scale lines 72 are arranged at intervals in the Y direction. A reference rod 9 is connected to the tool 5. The reference rod 9 extends to a position adjacent to the scale lines 72. By providing the reference rod 9, it is possible to more accurately know the position of the tool 5 in the Y direction. Specifically, before the scribing operation, the position where the tool 5 just touches the outer shell of the battery 6 in the Y direction can be used as a reference position. The first scale value corresponding to the tool 5 at this reference position is recorded through the reference rod 9. Then the tool 5 is moved away from the battery 6 in the Y direction. Next, the slide base 7 is moved to a farther position in the X direction, so that the tool 5 is moved away from the battery 6 in the X direction. Immediately afterwards, the tool 5 is moved closer to the middle position in the Y direction to a preset second scale value. The difference between the first scale value and the second scale value is the depth of scribing on the outer shell of the battery 6. Finally, driving the slide base 7 to move in the X direction enables the tool 5 to scribe on the outer shell of the battery 6. In this embodiment, the depth of scribing on the outer shell of the battery 6 is preferably about 1 mm. Therefore, the interval of the scale lines 72 in the Y direction is also preferably 1 mm.

[0041] In this embodiment, the support mechanism 3 includes a support wall 31, a support rod 32, and a guide rail platform 33. The support wall 31 is fixedly connected to the base 1. The support rod 32 is passed through the support wall 31, and the guide rail platform 33 is fixed to one end of the support rod 32. When the outer diameter of the support rod 32 is relatively large, only one support rod 32 can be connected between the support wall 31 and the guide rail platform 33. When the outer diameter of the support rod 32 is relatively small, two support rods 32 can be connected between the support wall 31 and the guide rail platform 33 to improve the stability of the fixed connection of the guide rail platform 33 relative to the base 1. Specifically, a guide rail 34 is provided on the guide rail platform 33, and the slide seat 7 is slidably connected to the guide rail platform 33 along the X direction through the connecting guide rail 34. The support mechanism 3 designed in this way has the advantages of simple structure and facilitating the realization of the slide seat 7 sliding along the X direction. In addition, the support mechanism 3 further includes a first nut 35 and a second nut 36. The first nut 35 and the second nut 36 are respectively threadedly connected to the support rod 32. Moreover, the support rod 32 passes outwards relative to the support wall 31, and the first nut 35 and the second nut 36 are respectively arranged on opposite sides of the support wall 31. When both the first nut 35 and the second nut 36 are tightened, the first nut 35 and the second nut 36 will jointly clamp the support wall 31. By providing the first nut 35 and the second nut 36, while realizing the function of fixing the support rod 32 on the support wall 31, when the first nut 35 and the second nut 36 are loosened, the telescopic length of the support rod 32 relative to the support wall 31 can also be adjusted, so as to adjust the position of the tool 5 in the Y direction, and further be compatible with the scribing operations of batteries 6 with larger or smaller widths, further improving the compatibility of the scribing device.

[0042] In this embodiment, the clamping plate mechanism 4 includes a support seat 41, a connecting rod 42, and a clamping plate 43. Among them, the support seat 41 is fixedly connected to the base 1. The connecting rod 42 is passed through the support seat 41, and the clamping plate 43 is fixed to one end of the connecting rod 42. The clamping plate 43 is arranged on the side opposite to the tool 5 and is used for the side of the battery 6 facing away from the tool 5 to abut against. The clamping plate mechanism 4 designed in this way has the advantages of simple structure and low cost. In addition, the clamping plate mechanism 4 further includes a third nut 44 and a fourth nut 45. The third nut 44 and the fourth nut 45 are respectively threadedly connected to the connecting rod 42, and the connecting rod 42 passes outwards relative to the support seat 41. The third nut 44 and the fourth nut 45 are respectively arranged on opposite sides of the support seat 41. When both the third nut 44 and the fourth nut 45 are tightened, the third nut 44 and the fourth nut 45 will jointly clamp the support seat 41. By providing the third nut 44 and the fourth nut 45, while realizing the function of fixing the connecting rod 42 on the support seat 41, when the third nut 44 and the fourth nut 45 are loosened, the telescopic length of the connecting rod 42 relative to the support seat 41 can also be adjusted, so as to adjust the position of the clamping plate 43 in the Y direction, and further be compatible with the scribing operations of batteries 6 with larger or smaller widths, further improving the compatibility of the scribing device.

[0043] In this embodiment, the top of the fixture 2 is provided with a downwardly recessed first limit groove 21 and a second limit groove 22, both of which are used to limit the position of the battery 6. The depth of the first limit groove 21 and the second limit groove 22 are preferably 50% to 70% of the height of the battery 6 to improve the stability of the battery 6 in the first limit groove 21 or the second limit groove 22. By simultaneously providing the first limit groove 21 and the second limit groove 22, the requirement of being able to mark both postures of the battery 6 can be met. Preferably, the first limiting groove 21 and the second limiting groove 22 are interconnected, the extension direction of the first limiting groove 21 points to the X direction, and the extension direction of the first limiting groove 21 and the extension direction of the second limiting groove 22 are perpendicular to each other, that is, the extension direction of the second limiting groove 22 points to the Y direction, so that the first limiting groove 21 and the second limiting groove 22 form a cross groove structure together, when the battery 6 is placed in the first limiting groove 21, the tool 5 can score the outer shell of the battery 6 in the length direction, and when the battery 6 is placed in the second limiting groove 22, the tool 5 can score the outer shell of the battery 6 in the width direction, that is, the function of scoring the outer shell of the battery 6 on both the long side and the short side can be realized, thereby achieving the scoring operation of the outer circumference of the battery 6, so as to facilitate the subsequent disassembly of the outer shell of the battery 6, thereby improving the efficiency of disassembling the outer shell of the battery 6. In addition, in actual operation, different jigs 2 can be replaced according to batteries 6 of different sizes to meet the purpose of quickly completing the scoring operation for batteries 6 of various sizes.

[0044] The above are only preferred embodiments of the present invention, and only specifically describe the technical principles of the present invention. These descriptions are only for the purpose of explaining the principles of the present invention, and cannot be interpreted as limiting the scope of protection of the present invention in any way. Based on the explanation here, any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention, and other specific implementation methods of the present invention that can be associated with by technicians in this field without creative labor, should be included in the scope of protection of the present invention.

Claims

1. A scoring device, characterized in that: It comprises a base (1), a fixture (2), a support mechanism (3), a clamping plate mechanism (4) and a cutting tool (5); The jig (2) is connected to the top of the base (1) and is used to limit the position of the workpiece to be engraved. The support mechanism (3) is respectively connected to the base (1) and the tool (5). The tool (5) is supported by the support mechanism (3) to be suspended above the jig (2). The tool (5) is connected to the support mechanism (3) in a sliding manner along a first direction. The tool (5) slides along the first direction to engrave the outer surface of the workpiece to be engraved on the jig (2). The clamping plate mechanism (4) is arranged on a side opposite to the tool (5) and is used to abut against a side of the workpiece to be engraved that is away from the tool (5).

2. The scoring device according to claim 1, characterized in that: The scoring device further comprises a slide (7), the tool (5) being connected to the slide (7), the slide (7) being slidably connected to the support mechanism (3) along the first direction, and the position of the tool (5) relative to the slide (7) along a horizontal second direction is adjustable, wherein the first direction and the second direction are perpendicular to each other.

3. The scoring device according to claim 2, characterized in that: The slide seat (7) is provided with a waist-shaped hole (71), the waist-shaped hole (71) extending in the second direction, and a bolt (8) for fixing the tool (5) on the slide seat (7) is passed through the waist-shaped hole (71).

4. The scoring device according to claim 2, characterized in that: The top surface of the slide seat (7) is provided with scale lines (72), the scale lines (72) are arranged at intervals along the second direction, and the tool (5) is connected to a marking rod (9), the marking rod (9) extends to a position adjacent to the scale lines (72).

5. The scoring device according to claim 2, characterized in that: The support mechanism (3) comprises a support wall (31), a support rod (32) and a guide rail platform (33); The support wall (31) is fixedly connected to the base (1); the support rod (32) is passed through the support wall (31); the guide rail platform (33) is fixed to one end of the support rod (32); a guide rail (34) is provided on the guide rail platform (33); and the slide seat (7) is slidably connected to the guide rail platform (33) along the first direction by connecting the guide rail (34).

6. The scoring device according to claim 5, characterized in that: The support mechanism (3) further comprises a first nut (35) and a second nut (36) respectively threadedly connected to the support rod (32); the support rod (32) protrudes outward relative to the support wall (31); the first nut (35) and the second nut (36) are respectively arranged on two opposite sides of the support wall (31) and are used to jointly clamp the support wall (31).

7. The scoring device according to claim 1, characterized in that: The clamping plate mechanism (4) comprises a support seat (41), a connecting rod (42) and a clamping plate (43); The support seat (41) is fixedly connected to the base (1), the connecting rod (42) is passed through the support seat (41), the clamping plate (43) is fixed to one end of the connecting rod (42), and the clamping plate (43) is arranged on a side opposite to the tool (5) and is used for abutting a side of the workpiece to be engraved that is away from the tool (5).

8. The scoring device according to claim 7, characterized in that: The clamping plate mechanism (4) further comprises a third nut (44) and a fourth nut (45) respectively threadedly connected to the connecting rod (42); the connecting rod (42) protrudes outward relative to the support seat (41); the third nut (44) and the fourth nut (45) are respectively arranged on two opposite sides of the support seat (41) and are used to jointly clamp the support seat (41).

9. The scoring device according to claim 7, characterized in that: A first limiting groove (21) and a second limiting groove (22) which are recessed downwards are arranged on the top of the jig (2), and the first limiting groove (21) and the second limiting groove (22) are both used to limit the position of the workpiece to be engraved.

10. The scoring device according to claim 9, characterized in that: The first limiting groove (21) and the second limiting groove (22) are connected to each other, the extension direction of the first limiting groove (21) points to the first direction, and the extension direction of the first limiting groove (21) and the extension direction of the second limiting groove (22) are perpendicular to each other, so that the first limiting groove (21) and the second limiting groove (22) together form a cross groove structure.