Quick opening and closing customizing device for drop-out fuse

Abstract

The invention relates to the technical field of drop-out fuses, in particular to a drop-out fuse rapid opening and closing customizing device which comprises a fuse, a drop-out rod and a drop-out head arranged on the drop-out rod. According to the rapid opening and closing customizing device for the drop-out fuse, through the arrangement of the annular magnet, when the top end of the insulating operating rod is close to the insulating shell, the annular magnet adsorbs the top end of the insulating operating rod, so that the top end of the insulating operating rod can directly enter the inner ring of the left annular shell and can also be adsorbed on the surface of the left annular shell; when the top end of the insulating operating rod directly enters the inner ring of the left ring shell, the insulating operating rod is pulled to perform opening and closing operation, and when the top end of the insulating operating rod is adsorbed on the surface of the left ring shell, the insulating operating rod moves along the surface of the left ring shell and enters the inner ring of the left ring shell through the entering part, so that the opening and closing operation is performed, and the operation is convenient; and the time spent by hooking the operating rod into the circular operating hole of the fuse is saved.

Description

Technical Field

[0001] The invention relates to the technical field of drop-out fuses, and in particular to a customized device for rapid opening and closing of drop-out fuses. Background Art

[0002] Nowadays, the existing high-voltage transmission lines in my country are increasingly widely used, and the maintenance tasks are increasing accordingly. Drop-type fuses are often used in outdoor overhead power distribution systems. The load-bearing parts fall to form a fracture, which plays a role in isolating and extinguishing arcs, and has played a role in isolating faulty equipment.

[0003] During normal operation of the existing drop-out fuse, it is necessary to put the L-shaped metal operating hook at the top of the insulating operating rod into the circular operating hole of the drop-out fuse, and hold the lower end of the link rod to pull it open. Because the installed fuse is high above the ground, when the operating part of the operating rod is hooked into the circular operating hole of the fuse, the top end shakes, resulting in a long time spent on hooking into the circular operating hole of the fuse, which affects the operating efficiency. Summary of the invention

[0004] In view of the problems existing in the above-mentioned existing customized devices for rapid opening and closing of drop-out fuses, the present invention is proposed.

[0005] Therefore, the object of the present invention is to provide a customized device for rapid opening and closing of a drop-out fuse, the purpose of which is to facilitate the insertion of the top end of the insulating operating rod into the circular operating hole of the fuse.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: comprising:

[0007] A fuse including a drop bar, a drop head disposed on the drop bar;

[0008] The quick docking mechanism includes an insulating shell, a magnetic attraction portion arranged in the insulating shell, a docking portion arranged on the insulating shell, a first clamping portion arranged on the docking portion, a second clamping portion arranged on the docking portion, a mounting portion arranged on the insulating shell and connected to the drop head, an entry portion arranged on the insulating shell, and a closing portion arranged on the insulating shell.

[0009] As a preferred solution of the customized device for rapid opening and closing of the drop-type fuse described in the present invention, wherein: the drop head includes a drop head cover arranged on the drop rod, a drop operation ring connecting piece arranged on the drop head cover, a cutting surface arranged on the drop operation ring connecting piece, and a mounting hole arranged on the drop operation ring connecting piece.

[0010] As a preferred solution of the customized device for rapid opening and closing of the drop-out type fuse described in the present invention, wherein: the insulating shell includes a left ring shell and a right ring shell, a left square shell arranged on the left ring shell, a right square shell arranged on the right ring shell, a placement groove arranged in the left ring shell and the right ring shell, and an installation groove arranged in the left square shell and the right square shell.

[0011] As a preferred solution of the customized device for rapid opening and closing of the drop-out fuse of the present invention, the magnetic attraction portion includes an annular magnet arranged in the placement groove and a rubber pad arranged on the annular magnet.

[0012] As a preferred solution of the customized device for rapid opening and closing of the drop-out fuse described in the present invention, the docking portion includes a docking convex strip arranged on the right ring shell and the right square shell, and a docking groove arranged on the left ring shell and the left square shell and adapted to the docking convex strip.

[0013] As a preferred solution of the customized device for rapid opening and closing of the drop-out fuse described in the present invention, the first clamping portion includes a clamping joint arranged on the docking convex strip and a first clamping extrusion section arranged on the clamping joint.

[0014] As a preferred solution of the customized device for rapid opening and closing of the drop-out type fuse described in the present invention, the second clamping portion includes a clamping groove arranged in the docking groove, a clamping block arranged in the clamping groove and adapted to the clamping joint, and a second clamping extrusion section arranged on the clamping block.

[0015] As a preferred solution of the customized device for rapid opening and closing of the drop-out fuse described in the present invention, the mounting portion includes bolt holes arranged on the left shell and the right shell and adapted to the mounting holes, and bolts arranged on the bolt holes.

[0016] As a preferred solution of the customized device for rapid opening and closing of the drop-out type fuse described in the present invention, the entry portion includes an entry shell opening arranged on the left ring shell and the right ring shell, and an entry magnetic opening arranged on the annular magnet, and the entry shell opening is located above the left ring shell.

[0017] As a preferred solution of the customized device for rapid opening and closing of the drop-out type fuse described in the present invention, the closing part includes a closing shaft arranged on the left ring shell and the right ring shell, a closing side plate arranged on the closing shaft, a closing arc plate arranged on the closing side plate, a connecting column arranged on the closing arc plate, and a connecting hole arranged on the closing arc plate and adapted to the connecting column.

[0018] The beneficial effects of the present invention are as follows: through the arrangement of the annular magnet, when the top end of the insulating operating rod is close to the insulating shell, the annular magnet adsorbs the top end of the insulating operating rod, so that the top end of the insulating operating rod may directly enter the inner ring of the left annular shell, or may be adsorbed on the surface of the left annular shell. When the top end of the insulating operating rod directly enters the inner ring of the left annular shell, the insulating operating rod can be pulled to perform opening and closing operations. When the top end of the insulating operating rod is adsorbed on the surface of the left annular shell, it moves along the surface of the left annular shell and enters the inner ring of the left annular shell through the entry part, thereby performing opening and closing operations. The operation is convenient and the time spent on hooking the operating rod into the circular operating hole of the fuse is saved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0020] Figure 1 This is a schematic diagram of the overall structure of the customized device for rapid opening and closing of drop-out fuses of the present invention.

[0021] Figure 2 It is a structural schematic diagram of the drop head of the customized device for rapid opening and closing of the drop-out fuse of the present invention.

[0022] Figure 3 This is a schematic diagram of the structure of the insulating shell of the customized device for rapid opening and closing of the drop-out fuse of the present invention.

[0023] Figure 4 It is a structural schematic diagram of the docking portion of the customized device for rapid opening and closing of the drop-out fuse of the present invention.

[0024] Figure 5 Customized device for quick opening and closing of drop-out fuse of the present invention Figure 3 A local enlarged schematic diagram of point A in the middle.

[0025] Figure 6 Customized device for quick opening and closing of drop-out fuse of the present invention Figure 4 A local enlarged schematic diagram of point B in the middle.

[0026] Figure 7 It is a structural schematic diagram of the closing part of the customized device for rapid opening and closing of the drop-out fuse of the present invention. DETAILED DESCRIPTION

[0027] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0028] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0029] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0030] Secondly, the present invention is described in detail with reference to the schematic diagram. When describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0031] Example 1

[0032] Reference Figure 1 to Figure 7 , which is the first embodiment of the present invention, provides a customized device for rapid opening and closing of a drop-out fuse, the device comprising:

[0033] The fuse 100 includes a drop bar 101 and a drop head 102 disposed on the drop bar 101;

[0034] The quick docking mechanism 200 includes an insulating shell 201, a magnetic attraction portion 202 arranged in the insulating shell 201, a docking portion 203 arranged on the insulating shell 201, a first clamping portion 204 arranged on the docking portion 203, a second clamping portion 205 arranged on the docking portion 203, an installation portion 206 arranged on the insulating shell 201 and connected to the drop head 102, an entry portion 207 arranged on the insulating shell 201, and a closing portion 208 arranged on the insulating shell 201.

[0035] During use, the magnetic attraction portion 202 is placed in the insulating shell 201, the insulating shell 201 is merged through the docking portion 203, and the insulating shell 201 is fixed by docking the first clamping portion 204 and the second clamping portion 205, thereby completing the assembly of the insulating shell 201, cutting and punching the drop head 102, and fixing the insulating shell 201 on the drop head 102 through the mounting portion 206, thereby completing the connection;

[0036] When performing opening and closing operations, since the magnetic attraction portion 202 is arranged in the insulating shell 201, when the top end of the insulating operating rod is close to the insulating shell 201, the magnetic attraction portion 202 adsorbs the top end of the insulating operating rod, so that the top end of the insulating operating rod may directly enter the inner ring of the insulating shell 201, or it may be adsorbed on the surface of the insulating shell 201. When the top end of the insulating operating rod directly enters the inner ring of the insulating shell 201, the insulating operating rod can be pulled to perform opening and closing operations. When the top end of the insulating operating rod is adsorbed on the surface of the insulating shell 201, it moves along the surface of the insulating shell 201 and enters the inner ring of the insulating shell 201 through the entry portion 207, thereby performing opening and closing operations.

[0037] Example 2

[0038] Reference Figure 1 and Figure 2 , which is the second embodiment of the present invention. This embodiment is different from the first embodiment in that: the drop head 102 includes a drop head cover 102a arranged on the drop rod 101, a drop operation ring connecting piece 102b arranged on the drop head cover 102a, a cutting surface 102c arranged on the drop operation ring connecting piece 102b, and a mounting hole 102d arranged on the drop operation ring connecting piece 102b.

[0039] Furthermore, the drop head cover 102a is fixedly set on the drop rod 101, and the drop operation ring connecting piece 102b is fixedly set on the drop head cover 102a. The existing drop operation ring connecting piece 102b has a metal operation ring. The metal operation ring is cut along the cutting surface 102c, and the remaining drop operation ring connecting piece 102b is used to open the installation hole 102d, and it is connected and fixed with the quick docking mechanism 200, so as to utilize the existing drop head cover 102a and save costs.

[0040] The remaining structures are the same as those of Example 1.

[0041] During use, the drop operation ring connecting piece 102b is cut along the cutting surface 102c, thereby removing the original metal circular operating ring of the fuse, retaining part of the drop operation ring connecting piece 102b, punching holes on the retained drop operation ring connecting piece 102b, and fixing the insulating shell 201 on the drop head cover 102a through the mounting portion 206, thereby completing the replacement of the insulating shell 201, so that the device can utilize the existing drop head 102, and there is no need to customize the drop head 102 and the quick docking mechanism 200 as a whole, saving costs.

[0042] Example 3

[0043] Reference Figure 3 to Figure 7, which is the third embodiment of the present invention. This embodiment is different from the second embodiment in that: the insulating shell 201 includes a left ring shell 201a and a right ring shell 201c, a left square shell 201b arranged on the left ring shell 201a, a right square shell 201d arranged on the right ring shell 201c, a placement groove 201e arranged in the left ring shell 201a and the right ring shell 201c, and an installation groove 201f arranged in the left square shell 201b and the right square shell 201d.

[0044] Furthermore, the left ring shell 201a and the right ring shell 201c are of annular design and are made of high-strength insulating material. The left square shell 201b and the right square shell 201d are of rectangular design. The left square shell 201b is connected to the left ring shell 201a, and the right square shell 201d is connected to the right ring shell 201c. The placement groove 201e is of annular design and is opened on the left ring shell 201a and the right ring shell 201c. When the left ring shell 201a and the right ring shell 201c are merged, the placement groove 201e forms an annular cavity for placing the magnetic attraction part 202.

[0045] The magnetic attraction portion 202 includes an annular magnet 202a disposed in the placement groove 201e and a rubber pad 202b disposed on the annular magnet 202a.

[0046] Furthermore, the annular magnet 202a is a customized 150-degree temperature-resistant national standard iron-boron magnet with strong magnetic force, and the rubber pad 202b is made of rubber material to increase the friction with the placement groove 201e, so that the annular magnet 202a can be squeezed and fixed when the left annular shell 201a and the right annular shell 201c are combined.

[0047] The docking portion 203 includes a docking ridge 203a disposed on the right ring shell 201c and the right square shell 201d, and a docking groove 203b disposed on the left ring shell 201a and the left square shell 201b and matched with the docking ridge 203a.

[0048] Furthermore, the docking ridge 203a is arranged along the edges of the right ring shell 201c and the right square shell 201d, and the docking groove 203b is arranged in cooperation with the docking ridge 203a, so that when the docking ridge 203a and the docking groove 203b are docked, the left ring shell 201a, the left square shell 201b, the right ring shell 201c, and the right square shell 201d can be docked at the same time, which facilitates the assembly of the left ring shell 201a and the right ring shell 201c.

[0049] The first clamping portion 204 includes a clamping joint 204a disposed on the butting convex strip 203a and a first clamping extrusion cut surface 204b disposed on the clamping joint 204a.

[0050] The second clamping portion 205 includes a clamping groove 205a disposed in the docking groove 203b, a clamping block 205b disposed in the clamping groove 205a and adapted to the clamping joint 204a, and a second clamping extrusion cut surface 205c disposed on the clamping block 205b.

[0051] Furthermore, the clamping joint 204a is arranged in an L-shape so that the clamping joint 204a can be clamped with the clamping block 205b. A plurality of clamping joints 204a are arranged along the docking ridge 203a. A slot is provided at the deformation position of the clamping joint 204a so that the clamping joint 204a is easier to deform, which facilitates the clamping of the clamping joint 204a with the clamping block 205b. The first clamping extrusion cut surface 204b is arranged, and the second clamping extrusion cut surface 205c squeezes the first clamping extrusion cut surface 204b so that the clamping joint 204a is easier to deform, which facilitates the clamping of the clamping joint 204a with the clamping block 205b.

[0052] The mounting portion 206 includes a bolt hole 206a disposed on the left shell 201b and the right shell 201d and matched with the mounting hole 102d, and a bolt 206b disposed on the bolt hole 206a.

[0053] Furthermore, bolt holes 206a are provided on the left shell 201b and the right shell 201d, so that the left shell 201b and the right shell 201d can be fixed to the left shell 201b by bolts 206b.

[0054] The entry portion 207 includes an entry shell opening 207a provided on the left annular shell 201a and the right annular shell 201c, and an entry magnet opening 207b provided on the annular magnet 202a. The entry shell opening 207a is located above the left annular shell 201a.

[0055] Furthermore, since the top of the insulating operating rod needs to be inserted into the insulating shell 201 with a diameter of 1 cm, the shell opening 207a is opened with a diameter of 1 cm, and the magnetic opening 207b is set so that the top of the insulating operating rod can enter the inner circle of the annular magnet 202a.

[0056] The closing portion 208 includes a closing shaft 208a arranged on the left annular shell 201a and the right annular shell 201c, a closing side plate 208b arranged on the closing shaft 208a, a closing arc plate 208c arranged on the closing side plate 208b, a connecting column 208d arranged on the closing arc plate 208c, and a connecting hole 208e arranged on the closing arc plate 208c and adapted to the connecting column 208d.

[0057] Furthermore, two closing rotating shafts 208a are provided, which are respectively arranged on the left ring shell 201a and the right ring shell 201c, so that the closed arc plate 208c can be divided into two halves, and the closing part 208 can be assembled at the same time as the insulating shell 201 is assembled. If the closed arc plate 208c is a whole, it is necessary to assemble the insulating shell 201 and then install the closing part 208, which is more troublesome. The design of dividing it into two parts can reduce the assembly steps and increase the efficiency of the device installation. The closed arc plate 208c is arranged in an arc shape, so that the top of the insulating operating rod can better pass through the shell opening 207a.

[0058] Furthermore, a magnetic insulating sheet can be provided at the bottom of the end of the closed arc plate 208c to prevent the closed arc plate 208c from being adsorbed after rotation, thereby ensuring the normal resetting of the closed arc plate 208c. A resetting torsion spring can be provided on the closed rotating shaft 208a to better reset the closed arc plate 208c.

[0059] Furthermore, by setting the closing portion 208, not only can the insulating operating rod be prevented from moving out through the shell opening 207a when opening the switch, but also when closing the switch, the insulating operating rod can squeeze the closed arc plate 208c to perform the closing operation, while preventing the insulating operating rod from moving out through the shell opening 207a.

[0060] The remaining structure is the same as that of Example 2.

[0061] During use, the annular magnet 202a is placed in the placement groove 201e, and the left ring shell 201a and the right ring shell 201c are docked and merged through the docking convex strip 203a and the docking groove 203b. When the left ring shell 201a and the right ring shell 201c are docked and merged, the clamping joint 204a is inserted into the clamping groove 205a, and the second clamping extrusion cut surface 205c squeezes the first clamping extrusion cut surface 204b to deform the clamping joint 204a. After the clamping joint 204a passes over the clamping block 205b, The clamping joint 204a is deformed and reset, and is clamped with the clamping block 205b, thereby fixing the left ring shell 201a and the right ring shell 201c, and fixing the left square shell 201b and the right square shell 201d, thereby completing the assembly of the insulating shell 201, inserting the drop operation ring connecting piece 102b into the installation groove 201f, and matching the bolt hole 206a with the installation hole 102d, and fixing the insulating shell 201 on the drop operation ring connecting piece 102b by the bolt 206b, thereby completing the connection;

[0062] When performing opening and closing operations, since the annular magnet 202a is arranged in the left annular shell 201a and the right annular shell 201c, when the top end of the insulating operating rod is close to the insulating shell 201, the annular magnet 202a absorbs the top end of the insulating operating rod, so that the top end of the insulating operating rod may directly enter the inner ring of the insulating shell 201, or it may be absorbed on the surface of the insulating shell 201. When the top end of the insulating operating rod directly enters the inner ring of the insulating shell 201, the insulating operating rod is pulled to perform opening and closing operations. When the top end of the insulating operating rod is absorbed on the surface of the insulating shell 201, it moves along the surface of the insulating shell 201 to the shell opening 207a. The insulating operating rod is operated to squeeze the closed arc plate 208c to separate the end of the closed arc plate 208c from the left annular shell 201a and the right annular shell 201c, so that the insulating operating rod enters the inner ring of the left annular shell 201a and the left square shell 201b through the shell opening 207a and the magnetic opening 207b, thereby performing opening and closing operations.

[0063] Importantly, it should be noted that the construction and arrangement of the present application shown in a plurality of different exemplary embodiments are only exemplary. Although only a few embodiments are described in detail in this disclosure, it should be readily understood by those who refer to this disclosure that many modifications are possible (e.g., the size, scale, structure, shape and proportion of various elements, and parameter values ​​(e.g., temperature, pressure, etc.), installation arrangement, use of materials, color, directional changes, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in the application. For example, the element shown as integrally formed can be composed of multiple parts or elements, the position of the element can be inverted or otherwise changed, and the nature or number or position of the discrete element can be changed or changed. Therefore, all such modifications are intended to be included in the scope of the present invention. The order or sequence of any process or method steps can be changed or reordered according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure of performing the function described herein, and is not only structurally equivalent but also equivalent structure. Without departing from the scope of the present invention, other replacements, modifications, changes and omissions can be made in the design, operating conditions and arrangement of the exemplary embodiments. Therefore, the invention is not limited to a specific embodiment, but extends to numerous modifications still falling within the scope of the appended claims.

[0064] Additionally, in order to provide a concise description of exemplary embodiments, all features of an actual embodiment (ie, those features that are not relevant to the best mode presently contemplated for carrying out the invention or those that are not relevant to implementing the invention) may not be described.

[0065] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A customized device for rapid opening and closing of drop-out fuses, characterized in that: include, A fuse (100) comprises a drop rod (101) and a drop head (102) arranged on the drop rod (101); A quick docking mechanism (200) comprises an insulating shell (201), a magnetic attraction portion (202) arranged in the insulating shell (201), a docking portion (203) arranged on the insulating shell (201), a first clamping portion (204) arranged on the docking portion (203), a second clamping portion (205) arranged on the docking portion (203), a mounting portion (206) arranged on the insulating shell (201) and connected to a drop head (102), an entry portion (207) arranged on the insulating shell (201), and a closing portion (208) arranged on the insulating shell (201).

2. The customized device for rapid opening and closing of drop-out fuses according to claim 1 is characterized in that: The drop head (102) comprises a drop head cover (102a) arranged on the drop rod (101), a drop operation ring connecting piece (102b) arranged on the drop head cover (102a), a cutting surface (102c) arranged on the drop operation ring connecting piece (102b), and a mounting hole (102d) arranged on the drop operation ring connecting piece (102b).

3. The customized device for rapid opening and closing of drop-out fuses according to claim 2 is characterized in that: The insulating shell (201) comprises a left ring shell (201a) and a right ring shell (201c), a left square shell (201b) arranged on the left ring shell (201a), a right square shell (201d) arranged on the right ring shell (201c), a placement groove (201e) arranged in the left ring shell (201a) and the right ring shell (201c), and an installation groove (201f) arranged in the left square shell (201b) and the right square shell (201d).

4. The customized device for rapid opening and closing of drop-out fuses according to claim 3 is characterized in that: The magnetic attraction portion (202) comprises an annular magnet (202a) arranged in the placement groove (201e) and a rubber pad (202b) arranged on the annular magnet (202a).

5. The customized device for rapid opening and closing of drop-out fuses according to claim 4 is characterized in that: The docking portion (203) comprises a docking convex strip (203a) provided on the right ring shell (201c) and the right square shell (201d), and a docking groove (203b) provided on the left ring shell (201a) and the left square shell (201b) and matched with the docking convex strip (203a).

6. The customized device for rapid opening and closing of drop-out fuses according to claim 5 is characterized in that: The first clamping portion (204) comprises a clamping joint (204a) arranged on the butting convex strip (203a) and a first clamping extrusion cut surface (204b) arranged on the clamping joint (204a).

7. The customized device for rapid opening and closing of drop-out fuses according to claim 6 is characterized in that: The second clamping portion (205) comprises a clamping groove (205a) arranged in the docking groove (203b), a clamping block (205b) arranged in the clamping groove (205a) and adapted to the clamping joint (204a), and a second clamping extrusion section (205c) arranged on the clamping block (205b).

8. The customized device for rapid opening and closing of drop-out fuses according to claim 7 is characterized in that: The mounting portion (206) comprises a bolt hole (206a) disposed on the left shell (201b) and the right shell (201d) and matched with the mounting hole (102d), and a bolt (206b) disposed on the bolt hole (206a).

9. The customized device for rapid opening and closing of drop-out fuses according to claim 8 is characterized in that: The entry portion (207) comprises an entry shell opening (207a) arranged on the left annular shell (201a) and the right annular shell (201c), and an entry magnet opening (207b) arranged on the annular magnet (202a), wherein the entry shell opening (207a) is located above the left annular shell (201a).

10. The customized device for rapid opening and closing of drop-out fuses according to claim 9 is characterized in that: The closing portion (208) includes a closing shaft (208a) arranged on the left annular shell (201a) and the right annular shell (201c), a closing side plate (208b) arranged on the closing shaft (208a), a closing arc plate (208c) arranged on the closing side plate (208b), a connecting column (208d) arranged on the closing arc plate (208c), and a connecting hole (208e) arranged on the closing arc plate (208c) and adapted to the connecting column (208d).

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