Locking mechanism

Abstract

The utility model discloses a locking mechanism which comprises a base, a locking mechanism and a locking mechanism. The base is provided with a discharging opening allowing a tool to stretch in. The abutting assembly is arranged on the base and located on one side of the discharging port, the abutting assembly comprises an abutting driving part and an abutting part, the abutting driving part is connected with the abutting part, the abutting part is located between the discharging port and the abutting driving part, and the abutting driving part drives the abutting part to move towards the discharging port so that the abutting part can be inserted into the tool at the discharging port; and the locking assembly is arranged on the base and located on one side of the moving path of the abutting piece, one end of the locking assembly stretches into the side, away from the discharging port, of the abutting piece when the abutting piece is inserted into the tool, and one end of the locking assembly stretches into the side, close to the discharging port, of the abutting piece when the abutting piece is reset. According to the locking mechanism, when power is suddenly cut off or air pressure is insufficient, due to the fact that one end of the locking assembly extends into the side, away from the discharging opening, of the abutting piece, resetting of the abutting piece can be limited, the abutting piece continues to clamp the tool, the tool can be prevented from falling off from the discharging opening of the base, and safety is good.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tool locking, in particular to a locking mechanism. BACKGROUND

[0002] With the diversification and individualization of the automobile market demand, the automobile industry is facing great pressure to continuously shorten the production cycle, improve production efficiency and product quality. In the production process, the tool needs to be replaced after a period of use. The current tool fixing is achieved by driving the clamping block to extend and insert into the tool through the telescopic cylinder. In the process of replacing the tool or production, when the power is suddenly cut off or the air pressure is insufficient, the clamping block will retract and loosen the tool, causing the tool to fall off, which is poor in safety. CONTENT OF THE UTILITY MODEL

[0003] In view of the above, it is necessary to propose a locking mechanism to increase the safety of the tool during the replacement of the tool or the production process.

[0004] The embodiment of the present application provides a locking mechanism, which comprises a base, a discharging port for allowing the tool to extend into the base, a abutting assembly arranged on the base and located on one side of the discharging port, the abutting assembly comprising an abutting driving member and an abutting member, the abutting driving member being connected with the abutting member, the abutting member being located between the discharging port and the abutting driving member, the abutting driving member driving the abutting member to move towards the discharging port, so that the abutting member is inserted into the tool at the discharging port, a locking assembly arranged on the base and located on one side of the moving path of the abutting member, one end of the locking assembly extending into the side of the abutting member away from the discharging port when the abutting member is inserted into the tool, and one end of the locking assembly extending into the side of the abutting member close to the discharging port when the abutting member is reset.

[0005] In some embodiments, the locking assembly comprises a locking member and a locking driving member, the locking driving member being connected with the locking member, the locking member being located between the locking driving member and the moving path of the abutting member, one end of the locking member extending into the side of the abutting member away from the discharging port when the locking driving member is powered off, and one end of the locking member retracting and moving out of the moving path of the abutting member under the driving of the locking driving member when the locking driving member is powered on.

[0006] In some embodiments, the locking driving member comprises a housing, an elastic member, a permanent magnet and an electromagnet, the housing being arranged on the base, the permanent magnet and the electromagnet being arranged opposite to each other in the housing, the elastic member being arranged in the housing and the two ends of the elastic member abutting against the permanent magnet and the electromagnet respectively, one end of the locking member being movably arranged in the housing and abutting against the permanent magnet, and the other end of the locking member extending out of the housing.

[0007] In some embodiments, the locking driving member further comprises a guide member, one end of the guide member is connected to the housing, and the other end of the guide member passes through the elastic member and the permanent magnet and extends into the locking member.

[0008] In some embodiments, the abutting assembly further comprises two guide rails, the two guide rails are arranged on the base in a spaced manner, and the abutting member is slidingly arranged between the two guide rails.

[0009] In some embodiments, the abutting member further comprises an insertion part for extending into the tooling and a connecting part connected to the insertion part on a side away from the base, and the insertion part and the connecting part are slidingly arranged between the two guide rails, and the abutting driving member is connected to the connecting part.

[0010] In some embodiments, the two guide rails are provided with protruding parts on sides close to each other, and the insertion part is slidingly arranged on the protruding parts.

[0011] In some embodiments, the two guide rails are provided with clamping parts on sides close to each other, the clamping parts are located on sides of the protruding parts away from the base, and the insertion part is recessed with a guide groove on a side close to the guide rails, and the guide groove is slidingly sleeved on the clamping part.

[0012] In some embodiments, the locking mechanism further comprises a limiting assembly, the limiting assembly comprises two limiting members, the two limiting members are arranged on the base in a spaced manner and located on opposite sides of the discharge port for limiting displacement of the tooling.

[0013] In some embodiments, each of the limiting members comprises a fixed member and a movable member, the fixed member is fixed to the base, and the movable member is detachably arranged on the fixed member, and the two movable members are located between the two fixed members and the distance between the two movable members is adjustable.

[0014] When the locking mechanism of the embodiments of the present application is in operation, the abutting driving member drives the abutting member to move towards the discharge port, so that the abutting member is inserted into the tooling at the discharge port, and the tooling can be clamped and fixed. When the tooling is not in operation, one end of the locking assembly extends into a side of the abutting member close to the discharge port when the abutting member is reset, so that the abutting member can be locked. When the tooling is replaced or in the production process, when power is suddenly cut off or air pressure is insufficient, since one end of the locking assembly extends into a side of the abutting member away from the discharge port, the reset of the abutting member can be limited, so that the abutting member continues to clamp the tooling and has a self-locking function, which can prevent the tooling from falling off the discharge port of the base, and the safety is better. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1is a schematic diagram of a stereoscopic structure of a locking tool when the locking mechanism is locked.

[0016] Figure 2 is Figure 1 is an exploded structure schematic diagram of the locking mechanism.

[0017] Figure 3 is Figure 1 is a schematic diagram of a stereoscopic structure of the locking tool in the locking mechanism.

[0018] Figure 4 is Figure 1 is a schematic diagram of a cross section of the locking mechanism along the A-A direction.

[0019] Figure 5 is Figure 2 is a schematic diagram of a cross section of the locking mechanism along the B-B direction.

[0020] Figure 6 is a schematic diagram of a stereoscopic structure of a locking tool when the locking mechanism is unlocked.

[0021] Main element symbol explanation: locking mechanism 100, base 10, discharge port 11, abutting assembly 20, abutting driving part 21, abutting part 22, insertion part 221, guide groove 2211, inclined surface 2212, connecting part 222, first connecting block 2221, second connecting block 2222, guide rail 23, protruding part 231, clamping part 232, guide plate 233, protruding block 2331, support 24, locking assembly 30, locking part 31, locking driving part 32, shell 321, elastic part 322, permanent magnet 323, electromagnet 324, guide part 325, limiting assembly 40, limiting part 41, fixing part 411, moving part 412, horizontal plate 4121, vertical plate 4122, locking tool 200, connecting block 210, adjusting block 220, T-shaped wedge block 230, wedge groove 2302. DETAILED DESCRIPTION

[0022] The embodiments of the present application are described in detail below with reference to the accompanying drawings. The embodiments described below are examples for explaining the present application and should not be understood as limiting the present application.

[0023] In the description of the utility model, it is necessary to understand that the terms indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the utility model. In addition, the terms "first" and "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first" and "second" can explicitly or implicitly include one or more features. In the description of the utility model, the meaning of "a plurality of" is two or more than two, unless otherwise specifically limited.

[0024] In the description of the utility model, it should be pointed out that, unless otherwise specifically defined and limited, the term "connection" should be broadly understood, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected, it can be mechanically connected, or it can be electrically connected or can communicate with each other, it can be directly connected, or indirectly connected through an intermediate medium, it can be the communication between two elements or the interaction relationship between two elements. For ordinary skilled in the art, the specific meaning of the above-mentioned term in the utility model can be understood according to the specific situation.

[0025] The following disclosure provides many different embodiments or examples for implementing different structures of the utility model. In order to simplify the disclosure of the utility model, the components and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the utility model. In addition, the utility model can repeatedly refer to numbers and / or letters in different examples, and such repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the utility model provides various specific examples of processes and materials, but those skilled in the art can realize the application of other processes and / or the use of other materials.

[0026] The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0027] Please refer to Figure 1 The embodiment of the application provides a locking mechanism 100 for clamping tool 200, and the locking mechanism 100 comprises a base 10, a pressing assembly 20 and a locking assembly 30.

[0028] The base 10 is provided with a discharging opening 11 for allowing the tool 200 to extend into. The abutting assembly 20 is arranged on the base 10 and located at one side of the discharging opening 11. The abutting assembly 20 comprises an abutting driving member 21 and an abutting member 22. The abutting driving member 21 is connected with the abutting member 22. The abutting member 22 is located between the discharging opening 11 and the abutting driving member 21. The abutting driving member 21 drives the abutting member 22 to move towards the discharging opening 11, so that the abutting member 22 is inserted into the tool 200 at the discharging opening 11. The locking assembly 30 is arranged on the base 10 and located at one side of the moving path of the abutting member 22. One end of the locking assembly 30 extends into the side of the abutting member 22 away from the discharging opening 11 when the abutting member 22 is inserted into the tool 200. One end of the locking assembly 30 extends into the side of the abutting member 22 close to the discharging opening 11 when the abutting member 22 is reset.

[0029] When the locking mechanism 100 of the embodiment is in operation, the abutting driving member 21 drives the abutting member 22 to move towards the discharging opening 11, so that the abutting member 22 is inserted into the tool 200 at the discharging opening 11. The tool 200 can be clamped and fixed. When the locking mechanism 100 is not in operation, one end of the locking assembly 30 extends into the side of the abutting member 22 close to the discharging opening 11. The abutting member 22 can be locked. When the tool 200 is replaced or in the production process, if the power is suddenly cut off or the air pressure is insufficient, the end of the locking assembly 30 extends into the side of the abutting member 22 away from the discharging opening 11. The reset of the abutting member 22 is limited. The abutting member 22 continues to clamp the tool 200 and has a self-locking function. The tool 200 can be prevented from falling off the discharging opening 11 of the base 10. The safety is better.

[0030] Please refer to Figure 2 The base 10 is generally plate-shaped.

[0031] In some embodiments, the abutting assembly 20 further comprises two guide rails 23. The two guide rails 23 are arranged on the base 10 and spaced apart along the first direction. The abutting member 22 is slidingly arranged between the two guide rails 23. In the embodiment, the first direction is the X-axis direction. The guide rails 23 are fixedly connected with the base 10 through bolt structures. By arranging the two guide rails 23, the movement of the abutting member 22 can be guided, so that the accuracy of the movement of the abutting member 22 is ensured.

[0032] In some embodiments, the abutting member 22 further comprises an insertion portion 221 and a connecting portion 222, the connecting portion 222 is connected to the insertion portion 221 away from the base 10, the insertion portion 221 and the connecting portion 222 are slidingly arranged between the two guide rails 23, and the abutting driving member 21 is connected to the connecting portion 222. The insertion portion 221 is substantially cuboid, and a slope 2212 is arranged on the side of the insertion portion 221 away from the base 10, the slope 2212 is used to extend into the tooling 200; the connecting portion 222 is L-shaped block structure. Specifically, the connecting portion 222 comprises a first connecting block 2221 and a second connecting block 2222 arranged perpendicularly on one side of the first connecting block 2221, the first connecting block 2221 is connected to the side of the insertion portion 221 away from the base 10 and connected to the abutting driving member 21, the size of the first connecting block 2221 is larger than the size of the second connecting block 2222, so that the first connecting block 2221 and the second connecting block 2222 can be connected together to form an L-shaped block structure, and the first connecting block 2221 and the second connecting block 2222 can be an integral structure or a split structure.

[0033] Please see Figure 3 The tooling 200 comprises a connecting block 210, an adjusting block 220 and a T-shaped wedge block 230, the adjusting block 220 is arranged between the connecting block 210 and the T-shaped wedge block 230, the size of the adjusting block 220 is smaller than the size of the connecting block 210, and a wedge groove 2302 is arranged on each side of the T-shaped wedge block 230. It can be understood that in other embodiments, a dovetail groove can be arranged on each side of the T-shaped wedge block 230. Please see Figure 4 When the tooling 200 is locked, the insertion portion 221 of the abutting member 22 is inserted into the wedge groove 2302 of the tooling 200.

[0034] In some embodiments, the side of the two guide rails 23 close to each other is provided with a protruding portion 231, and the insertion portion 221 is slidingly arranged on the protruding portion 231. The guide rail 23 is composed of two laminated guide plates 233, and the protruding portion 231 is composed of two laminated protruding blocks 2331, the two protruding blocks 2331 are arranged on the same side of the two guide plates 233 and abut each other. By arranging the protruding portion 231, the abutting member 22 can be supported and suspended, a certain space can be left between the abutting member 22 and the base 10 to arrange other structures, and the abutting member 22 can slide on the protruding portion 231.

[0035] In some embodiments, the two guide rails 23 are provided with clamping portions 232 on one side close to each other. The clamping portions 232 are in strip shape and are located on the side of the protruding portions 231 away from the base 10. The insertion portion 221 is recessed with a guide groove 2211 on one side close to the guide rail 23. The guide groove 2211 is sleeved on the clamping portion 232. By providing the clamping portion 232 and the guide groove 2211, the movement of the abutting member 22 can be guided to ensure the accuracy of the movement of the abutting member 22 and prevent the abutting member 22 from being separated from the guide rail 23.

[0036] In some embodiments, the abutting assembly 20 further comprises two supports 24 provided on the base 10. The two supports 24 are spaced apart along the second direction. The abutting driving member 21 is provided on the two supports 24. In the embodiment, the second direction is the Y-axis direction. The abutting driving member 21 is a pneumatic cylinder. The supports 24 are fixedly connected to the base 10 by a bolt structure.

[0037] In some embodiments, the locking assembly 30 comprises a locking member 31 and a locking driving member 32. The locking driving member 32 is connected to the locking member 31. The locking member 31 is located between the locking driving member 32 and the movement path of the abutting member 22. One end of the locking member 31 extends into the side of the abutting member 22 away from the discharge port 11 when the locking driving member 32 is powered off. One end of the locking member 31 is retracted and moved out of the movement path of the abutting member 22 under the driving of the locking driving member 32 when the locking driving member 32 is powered on.

[0038] Please refer to Figure 5 In some embodiments, the locking driving member 32 comprises a housing 321, an elastic member 322, a permanent magnet 323 and an electromagnet 324. The housing 321 is provided on the base 10. The permanent magnet 323 and the electromagnet 324 are oppositely arranged in the housing 321. The elastic member 322 is arranged in the housing 321 and the two ends of the elastic member 322 abut against the permanent magnet 323 and the electromagnet 324 respectively. One end of the locking member 31 is movably arranged in the housing 321 and abuts against the permanent magnet 323. The other end of the locking member 31 extends out of the housing 321. In the embodiment, the housing 321 is fixedly connected to the base 10 by a bolt structure. The locking member 31 is in T-shaped structure. One end of the locking member 31 is movably clamped in the housing 321. The elastic member 322 is a spring. In this way, by powering the electromagnet 324, the electromagnet 324 can magnetically attract the permanent magnet 323 and compress the elastic member 322, so that one end of the locking member 31 away from the electromagnet 324 moves towards the electromagnet 324 to move one end of the locking member 31 away from the electromagnet 324 out of the movement path of the abutting member 22. When powered off, one end of the locking member 31 moves away from the electromagnet 324 under the compression of the elastic member 322, so that one end of the locking member 31 extends into the side of the abutting member 22 away from the discharge port 11.

[0039] It can be understood that in other embodiments, the locking driving member 32 can be a pneumatic device or a servo motor, which can drive the locking member 31 to move so that one end of the locking member 31 extends into the side of the abutting member 22 away from the discharge port 11 or moves out of the movement path of the abutting member 22.

[0040] In some embodiments, the locking driving member 32 further comprises a guide member 325, which is a rod-shaped, is arranged in the housing 321, one end of the guide member 325 is connected to the housing 321, and the other end of the guide member 325 extends into the locking member 31 through the elastic member 322 and the permanent magnet 323. By arranging the guide member 325, the movement of the locking member 31 can be guided to ensure the accuracy of the movement of the locking member 31.

[0041] Please continue to see Figure 2 In some embodiments, the locking mechanism 100 further comprises a limiting assembly 40, which comprises two limiting members 41, the two limiting members 41 are arranged on the base 10 in a spaced manner and are located on opposite sides of the discharge port 11, and are used to limit the displacement of the tooling 200. In this embodiment, the limiting member 41 is fixedly connected to the base 10 by a bolt structure. By arranging two limiting members 41 to limit the displacement of the tooling 200, the tooling 200 can be prevented from shaking, and the insertion part 221 can be accurately inserted into the wedge groove 2302 of the tooling 200.

[0042] In some embodiments, each limiting member 41 comprises a fixed member 411 and a moving member 412, the fixed member 411 is plate-shaped and is fixed to the base 10, and the moving member 412 is L-shaped and is detachably arranged on the fixed member 411, the two moving members 412 are located between the two fixed members 411 and the distance between the two moving members 412 is adjustable. By detachably arranging the moving member 412 on the fixed member 411, the distance between the two moving members 412 can be adjusted, so that the locking mechanism is suitable for toolings 200 of different sizes. When in use, the adjusting block 220 and the T-shaped wedge block 230 of the tooling 200 can be located between the two moving members 412, and the moving member 412 abuts against the connecting block 210. Specifically, the moving member 412 comprises a horizontal plate 4121 and a vertical plate 4122 connected to one end of the horizontal plate 4121, the horizontal plate 4121 is connected to the side of the fixed member 411 away from the base 10, and the vertical plate 4122 is arranged on one side of the fixed member 411 and located between the two fixed members 411.

[0043] The implementation process of the locking mechanism 100 of the embodiment of the present application is as follows:

[0044] When it is necessary to replace the tooling 200, the fork of the forklift is disassembled and pushed into the lower part of the discharge port 11 of the base 10, the positioning column on the fork is aligned with the positioning hole on the tooling 200, and the fork is raised so that the positioning column extends into the positioning hole of the tooling 200.

[0045] The electromagnet 324 is energized, please refer to Figure 6 , the electromagnet 324 magnetically attracts the permanent magnet 323 and compresses the elastic member 322, so that the end of the locking member 31 away from the electromagnet 324 moves towards the electromagnet 324, so that the end of the locking member 31 away from the electromagnet 324 moves out of the movement path of the abutting member 22, the abutting driving member 21 drives the abutting member 22 to move away from the discharge port 11, so that the abutting member 22 is separated from the tool 200, the electromagnet 324 is de-energized, and the locking member 31 moves away from the electromagnet 324 under the compression of the elastic member 322, so that one end of the locking member 31 extends into the side of the abutting member 22 close to the discharge port 11, locking the abutting member 22;

[0046] The locking mechanism 100 is moved as a whole, and the tool 200 is separated from the discharge port 11, and the fork of the forklift moves the tool 200 to the corresponding tool library;

[0047] The tool 200 to be replaced is moved to below the discharge port 11 of the locking mechanism 100 by the forklift;

[0048] The locking mechanism 100 is moved as a whole, and the tool 200 is separated from the discharge port 11, and the fork of the forklift moves the tool 200 to the corresponding tool library;

[0049] Please continue to refer to Figure 1 , the electromagnet 324 is energized, the electromagnet 324 magnetically attracts the permanent magnet 323 and compresses the elastic member 322, so that the end of the locking member 31 away from the electromagnet 324 moves towards the electromagnet 324, so that the end of the locking member 31 away from the electromagnet 324 moves out of the movement path of the abutting member 22, the abutting driving member 21 drives the abutting member 22 to move towards the discharge port 11, so that the abutting member 22 is inserted into the tool 200 at the discharge port 11, realizing the clamping and fixing of the tool 200;

[0050] The electromagnet 324 is de-energized, and the locking member 31 moves away from the electromagnet 324 under the compression of the elastic member 322, so that one end of the locking member 31 extends into the side of the abutting member 22 away from the discharge port 11, locking the abutting member 22.

[0051] The locking mechanism 100 of the embodiment of the application adopts a mechanical, pneumatic and electric combined structure, which ensures that the tool 200 will not fall off during replacement or production, is safe and reliable, and realizes rapid and accurate replacement of the tool 200 through optimization of the structure, ensuring safe production.

[0052] It is apparent that the present application is not limited to the details of the foregoing exemplary embodiments, and thus modifications and equivalent arrangements can be made to the application without departing from the spirit or scope of the application. Therefore, the scope of the application should be defined by the appended claims rather than by the foregoing description, and all changes that come within the meaning and range of equivalents are intended to be embraced therein.

[0053] Finally, it should be noted that the above embodiments are merely used to illustrate the technical solutions of the present application, rather than limit the present application. Although the present application is described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or equivalently replaced without departing from the spirit and scope of the present application.

Claims

1. A lock mechanism, characterized in that The utility model provides a device for inserting and locking workpiece, which comprises: a base, a discharging opening is formed in the base to allow a workpiece to be inserted into the base; a pressing assembly is arranged on the base and located at one side of the discharging opening, the pressing assembly comprises a pressing driving member and a pressing member, the pressing driving member is connected with the pressing member, the pressing member is located between the discharging opening and the pressing driving member, and the pressing driving member drives the pressing member to move towards the discharging opening so that the pressing member is inserted into the workpiece at the discharging opening; a locking assembly is arranged on the base and located at one side of the moving path of the pressing member, one end of the locking assembly extends into the side of the pressing member away from the discharging opening when the pressing member is inserted into the workpiece, and one end of the locking assembly extends into the side of the pressing member close to the discharging opening when the pressing member is reset.

2. The locking mechanism of claim 1, wherein The locking assembly comprises a locking member and a locking driving member, the locking driving member is connected with the locking member, the locking member is located between the locking driving member and the moving path of the pressing member, one end of the locking member extends into the side of the pressing member away from the discharging opening when the locking driving member is powered off, and one end of the locking member is retracted and moves out of the moving path of the pressing member under the driving of the locking driving member when the locking driving member is powered on.

3. The locking mechanism of claim 2, wherein, The locking driving member comprises a housing, an elastic member, a permanent magnet and an electromagnet, the housing is arranged on the base, the permanent magnet and the electromagnet are oppositely arranged in the housing, the elastic member is arranged in the housing and the two ends of the elastic member abut against the permanent magnet and the electromagnet respectively, one end of the locking member is movably arranged in the housing and abuts against the permanent magnet, and the other end of the locking member extends out of the housing.

4. The locking mechanism of claim 3, wherein The locking driving member further comprises a guide member, the guide member is arranged in the housing, one end of the guide member is connected with the housing, and the other end of the guide member penetrates through the elastic member and the permanent magnet and extends into the locking member.

5. The locking mechanism of claim 1, wherein The pressing assembly further comprises two guide rails, the two guide rails are spaced apart and arranged on the base, and the pressing member is slidingly arranged between the two guide rails.

6. The locking mechanism of claim 5, wherein The pressing member further comprises an insertion part for extending into the workpiece and a connecting part, the connecting part is connected to the side of the insertion part away from the base, and the insertion part and the connecting part are slidingly arranged between the two guide rails, wherein the pressing driving member is connected with the connecting part.

7. The locking mechanism of claim 6, wherein The side of the two guide rails close to each other is provided with a protruding part, and the insertion part is slidingly arranged on the protruding part.

8. The locking mechanism of claim 7, wherein The side of the two guide rails close to each other is provided with a clamping part, the clamping part is located on the side of the protruding part away from the base, the side of the insertion part close to the guide rail is recessed with a guide groove, and the guide groove is slidingly sleeved with the clamping part.

9. The locking mechanism of claim 1, wherein The locking mechanism further comprises a limiting assembly, the limiting assembly comprises two limiting members, the two limiting members are spaced apart and arranged on the base and located at opposite sides of the discharging opening, and are used for limiting the displacement of the workpiece.

10. The locking mechanism of claim 9, wherein, Each of the limiting members comprises a fixed part and a movable part, the fixed part is fixed to the base, the movable part is detachably arranged on the fixed part, two movable parts are located between two fixed parts, and the distance between the two movable parts is adjustable.

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