Lifting platform for mounting and dismounting gantry crane

Abstract

The lifting platform comprises a base and a lifting part arranged on the base, the lifting part comprises a plurality of stand column assemblies which are evenly distributed above the base in a surrounding mode, the stand column assemblies are detachably connected with the base through first quick-release assemblies, and the first quick-release assemblies are detachably connected with the base through second quick-release assemblies. The lifting component further comprises a working platform and a plurality of lifting assemblies which are arranged on the stand column assemblies and used for lifting the working platform, and the lifting assemblies correspond to the stand column assemblies one to one. And compared with a traditional one-by-one assembly structure, the lifting platform assembly and disassembly structure has the advantages that the assembly and disassembly time of the lifting platform is greatly shortened, and the transition efficiency of the gantry crane is effectively improved.

Description

Technical Field

[0001] This utility model relates to the field of engineering machinery technology, specifically to a lifting platform for the installation and dismantling of gantry cranes. Background Technology

[0002] Gantry cranes, as large lifting equipment, are widely used in concrete road construction projects for operations such as hoisting precast beams and slabs and transferring construction materials. Due to the linear nature of road construction, frequent relocation of work sections is required (equipment needs to be redeployed on average every 3-5 kilometers), which places extremely high demands on the efficiency of the assembly and disassembly of the supporting lifting platform.

[0003] Traditional modular lifting platforms rely on manual assembly of each component, requiring the tightening of numerous bolts. Each assembly and disassembly is time-consuming, severely hindering construction progress. Actual measurement data from a highway project shows that the low efficiency of traditional platforms significantly impacts the relocation efficiency of gantry cranes. Therefore, it is necessary to develop a lifting platform capable of rapid installation and disassembly to improve the relocation efficiency of gantry cranes. Utility Model Content

[0004] The main purpose of this utility model is to provide a lifting platform for the installation and dismantling of gantry cranes, aiming to solve the technical problem of low assembly and dismantling efficiency of traditional assembled lifting platforms in the prior art.

[0005] To achieve the above objectives, the present invention proposes a lifting platform for the installation and dismantling of a gantry crane, comprising a base and a lifting component disposed on the base. The lifting component includes multiple column assemblies evenly distributed around the base. The column assemblies are detachably connected to the base via a first quick-release assembly. The lifting component also includes a working platform and multiple lifting components disposed on the multiple column assemblies for lifting the working platform. Each lifting component corresponds to each column assembly.

[0006] Preferably, the column assembly includes a first column, one end of which is recessed to form a sliding hole, the extension direction of which is the same as the extension direction of the first column, a second column is slidably disposed in the sliding hole, one end of which extends out of the sliding hole and the other end is located in the sliding hole, and the column assembly further includes a moving component for driving the second column to slide in the sliding hole.

[0007] Preferably, the moving assembly includes a piston disposed on the second column at the inner end of the sliding hole. The piston is clearance-fitted with the sliding hole. The space between the bottom of the sliding hole and the side of the piston away from the second column forms a liquid storage space for storing liquid. The moving assembly includes an oil tank, an oil pump, and a delivery pipe disposed above the base. The delivery pipe is used to connect the liquid storage space, the oil tank, and the oil pump to each other. The oil pump is used to transport liquid in the oil tank to the liquid storage space through the delivery pipe or to transport liquid in the liquid storage space to the oil tank. The delivery pipe connecting the liquid storage space and the oil pump is detachably connected.

[0008] Preferably, the first quick-release assembly includes a first connecting seat fixed above the base, a second connecting seat on the side of the first connecting seat away from the base, the side of the second connecting seat away from the first connecting seat fixed to the end of the first column away from the sliding hole, a plug on the side of the second connecting seat near the first connecting seat, a recessed hole for inserting a socket on the side of the first connecting seat near the second connecting seat, a first receiving groove formed by a transverse recess on the wall of the hole, an electromagnet fixed to the bottom of the first receiving groove, a first rack on the side of the electromagnet away from the bottom of the first receiving groove, a second receiving groove formed by a transverse recess on the outer wall of the plug, a metal plate movably connected to the bottom of the second receiving groove by a first elastic member in the second receiving groove, a second rack on the side of the metal plate away from the second receiving groove, the electromagnet being used to attract the metal plate so that the second rack meshes with the first rack, and an orienting member for fixing the moving direction of the metal plate in the second receiving groove.

[0009] Preferably, the directional component includes a guide rod laterally disposed on the side of the metal plate near the bottom of the second receiving groove, and the bottom of the second receiving groove is recessed to form a limiting sliding hole for the guide rod to slide.

[0010] Preferably, the lifting assembly includes a first support plate horizontally disposed at one end of the second column away from the first column, a first motor disposed on the first support plate, and the first motor being connected to the work platform via a first cable wound on its output shaft.

[0011] Preferably, the moving component further includes a positioning component for fixing the position of the second column within the sliding hole.

[0012] Preferably, the positioning component includes a second support plate laterally disposed on the outer wall of the second column, the second support plate being located outside the sliding hole, and a third support plate vertically disposed on the side of the second support plate away from the second column. The extension direction of the third support plate is parallel to the extension direction of the first column. The third support plate is located outside the first column, and a recessed receiving hole is provided on the side of the third support plate near the first column. A plug is slidably disposed in the receiving hole. One end of the plug near the bottom of the receiving hole is connected to the receiving hole through a second elastic member. The second elastic member is used to push the end of the plug away from the third receiving hole out of the receiving hole. A plurality of slots for plug insertion are evenly distributed on the side of the outer wall of the first column near the third support plate. The distribution direction of the plurality of slots is along the extension direction of the first column. The positioning component also includes a retraction member for moving the plug toward the side near the receiving hole and receiving the plug into the receiving hole.

[0013] Preferably, the retraction component includes a pull rod, a second cable, and a second motor; one end of the pull rod is connected to the side of the plug near the receiving hole, and the other end slides through the third support plate and extends to the side of the third support plate opposite to the first column; the second motor is located on the side of the third support plate opposite to the first column, and is connected to the end of the pull rod opposite to the plug through the second cable.

[0014] Preferably, the groove wall on the side of the slot near the base extends in the same direction as the movement direction of the plug, forming a lower groove wall; the groove opening on the side of the slot away from the base gradually moves away from the base, forming an upper groove wall that is inclined towards the extension direction of the slot.

[0015] In this invention, a modular structure is formed by combining multiple surrounding column components with quick-release components, significantly reducing the amount of bolt tightening work. The evenly distributed design enhances platform stability and allows for segmented assembly and disassembly. The first quick-release component enables rapid separation of the base and column components, greatly shortening the assembly and disassembly time of the lifting platform compared to traditional piece-by-piece assembly, effectively improving the relocation efficiency of the gantry crane. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0018] Figure 2 This is a schematic diagram of the overall cross-sectional structure of this utility model;

[0019] Figure 3 For the present utility model Figure 2 A magnified schematic diagram of the structure of area A in the diagram;

[0020] Figure 4 For the present utility model Figure 2 A magnified schematic diagram of the B region in the diagram.

[0021] Explanation of icon numbers:

[0022] 1. Base; 2. Lifting component; 21. Column assembly; 211. First column; 211a. Sliding hole; 211b. Slot; 212. Second column; 213. Oil pump; 214. Oil tank; 215. Piston; 22. Positioning assembly; 221. Second support plate; 222. Third support plate; 222a. Receiving hole; 223. Bolt; 224. Second elastic component; 225. Pull rod; 226. Second cable; 227. Second motor; 23. 1. Lifting assembly; 231. First support plate; 232. First motor; 233. First cable; 24. Working platform; 3. First quick-release assembly; 31. First connecting seat; 31a. Insertion hole; 31b. First receiving slot; 32. Second connecting seat; 33. Insert block; 33a. Second receiving slot; 33b. Limiting sliding hole; 34. First rack; 35. Electromagnet; 36. Metal plate; 37. Second rack; 38. First elastic component; 39. Guide rod.

[0023] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0025] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0026] Furthermore, in this utility model, the use of terms such as "first," "second," etc., is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0027] In this utility model, unless otherwise explicitly specified and limited, the terms "connection," "fixing," etc., should be interpreted broadly. For example, "fixing" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0028] Furthermore, the technical solutions of the various embodiments of this utility model can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0029] This utility model proposes a lifting platform for the installation and dismantling of gantry cranes.

[0030] Please refer to Figures 1 to 4 The lifting platform for installing and dismantling the gantry crane includes a base 1 and a lifting component 2 mounted on the base 1. The lifting component includes multiple column assemblies 21 evenly distributed around the base 1. The column assemblies 21 are detachably connected to the base 1 via a first quick-release assembly 3. The lifting component 2 also includes a working platform 24 and multiple lifting components 23 mounted on the multiple column assemblies 21 for lifting the working platform 24. Each lifting component 23 corresponds to each column assembly 21.

[0031] In this invention, a modular structure is formed by combining multiple surrounding column assemblies 21 with quick-release components, significantly reducing the amount of bolt tightening work. The evenly distributed design enhances platform stability and allows for segmented assembly and disassembly. The first quick-release component 3 enables rapid separation of the base 1 from the column assembly 21. Compared to traditional piece-by-piece assembly, this structure greatly shortens the assembly and disassembly time of the lifting platform, effectively improving the relocation efficiency of the gantry crane.

[0032] Please refer to the appendix. Figure 1-2The column assembly 21 includes a first column 211 with a recessed sliding hole 211a at one end. The sliding hole 211a extends in the same direction as the first column 211. A second column 212 is slidably disposed within the sliding hole 211a, with one end extending out of the sliding hole 211a and the other end located within it. The column assembly 21 also includes a moving component for driving the second column to slide within the sliding hole 211a. The column assembly 21 adopts a telescopic double-column structure, adjusting the overall height of the first column 211 and the second column 212 by sliding the second column 212 within the first column 211. It can be retracted during transportation to reduce space occupation, and quickly deployed during installation via the moving component, avoiding the time-consuming hoisting of traditional segmented column splicing.

[0033] Please refer to the appendix. Figure 1-2 The moving assembly includes a piston 215 disposed on the inner end of the sliding hole 211a of the second column 212. The piston 215 is clearance-fitted with the sliding hole 211a. The space between the bottom of the sliding hole 211a and the side of the piston 215 away from the second column 212 forms a liquid storage space for storing liquid. The moving assembly includes an oil tank 214, an oil pump 213 and a delivery pipe disposed above the base 1. The delivery pipe is used to connect the liquid storage space, the oil tank 214 and the oil pump 213 to each other. The oil pump 213 is used to transport the liquid in the oil tank 214 to the liquid storage space through the delivery pipe or to transport the liquid in the liquid storage space to the oil tank 214. The delivery pipe connecting the liquid storage space and the oil pump 213 is detachably connected. The oil storage tank 214, oil pump 213, liquid storage space and liquid delivery pipe cooperate to form a hydraulic drive system. The extension and retraction control of the second column 212 can be realized. The oil storage tank 214 and oil pump 213 are integrated on the base 1 to form an independent power unit. Compared with mechanical gear transmission, the hydraulic system can provide greater driving force and stepless speed regulation. With the detachable pipeline design, the components can be separated by simply disconnecting the pipeline during disassembly, which greatly improves the disassembly efficiency compared with the traditional hydraulic system.

[0034] Please refer to the appendix. Figure 2-3The first quick-release assembly 3 includes a first connecting seat 31 fixed above the base 1. A second connecting seat 32 is provided on the side of the first connecting seat 31 facing away from the base 1. The side of the second connecting seat 32 facing away from the first connecting seat 31 is fixed to one end of the first column 211 facing away from the sliding hole 211a. A plug 33 is provided on the side of the second connecting seat 32 near the first connecting seat 31. A socket 31a for insertion is recessed on the side of the first connecting seat 31 near the second connecting seat 32. A first receiving groove 31b is formed by a transverse recess on the wall of the socket 31a. The bottom of the first receiving groove 31b is fixed... An electromagnet 35 is provided. A first rack 34 is provided on the side of the electromagnet 35 facing away from the bottom of the first receiving groove 31b. A second receiving groove 33a is formed by a transverse recess in the outer wall of the insert block 33. A metal plate 36 is provided in the second receiving groove 33a, which is movably connected to the bottom of the second receiving groove 33a by a first elastic member 38. A second rack 37 is provided on the side of the metal plate 36 facing away from the second receiving groove 33a. The electromagnet 35 is used to attract the metal plate 36 so that the second rack 37 engages with the first rack 34. A directional member is also provided in the second receiving groove 33a to fix the moving direction of the metal plate 36. A quick-locking mechanism is formed by the electromagnet 35 attracting the metal plate 36 and engaging the first rack 34 and the second rack 37. When the electromagnet 35 is energized, it attracts the metal plate 36 and moves it towards the side of the electromagnet 35, so that the first rack 34 and the second rack 37 engage with each other. They disengage when the power is off. The directional member prevents the metal plate 36 from deflecting, ensuring engagement accuracy.

[0035] Please refer to the appendix. Figure 3 The directional component includes a guide rod 39 laterally positioned on the side of the metal plate 36 near the bottom of the second receiving groove 33a. The bottom of the second receiving groove 33a is recessed to form a limiting sliding hole 33b for the guide rod 39 to slide. The guide rod 39 and the limiting sliding hole 33b form a forced guiding path, eliminating movement deviation of the metal plate 36. During the movement of the metal plate 36 attracted by the electromagnet 35, the metal plate 36 is prevented from deflecting, thus improving the meshing power of the rack and pinion mechanism and significantly reducing the failure rate of the quick-release assembly.

[0036] Please refer to the appendix. Figure 2 The lifting assembly 23 includes a first support plate 231 horizontally disposed at one end of the second column 212 opposite to the first column 211. A first motor 232 is mounted on the first support plate 231, and the first motor 232 is connected to the work platform 24 via a first cable 233 wound on its output shaft. The lifting operation of the work platform 24 is achieved through the coordinated operation of multiple first motors 232 of the multiple lifting assemblies 23 on the base 1.

[0037] Please refer to the appendix. Figure 2The moving assembly also includes a positioning component 22 for fixing the position of the second column 212 within the sliding hole 211a. The positioning component 22 is used to fix the position of the second column 212 after it has risen to the designated position, eliminating the risk of pressure failure in the hydraulic drive system, ensuring that the work platform 24 does not settle during hoisting, and further improving the safety of construction operations.

[0038] Please refer to the appendix. Figure 2 and 4 The positioning component 22 includes a second support plate 221 horizontally disposed on the outer wall of the second column 212. The second support plate 221 is located outside the sliding hole 211a. A third support plate 222 is vertically disposed on the side of the second support plate 221 away from the second column 212. The extension direction of the third support plate 222 is parallel to the extension direction of the first column 211. The third support plate 222 is located outside the first column 211. A recessed receiving hole 222a is provided on the side of the third support plate 222 near the first column 211. A plug 223 is slidably disposed in the receiving hole 222a. One end of the pin 223 near the bottom of the receiving hole 222a is connected to the receiving hole 222a via a second elastic member 224. The second elastic member 224 is used to push the end of the pin 223 away from the third receiving groove out of the receiving hole 222a. Multiple slots 211b for inserting the pin 223 are evenly spaced on the outer wall of the first column 211 near the third support plate 222. The distribution direction of the multiple slots 211b is along the extension direction of the first column 211. The positioning component 22 also includes a retractor for moving the pin 223 towards the side near the receiving hole 222a and receiving the pin 223 into the receiving hole 222a. The cooperation between the elastic pin 223 and the stepped slots 211b achieves height-level self-locking. After the second column 212 extends or retracts to the designated position, the retractor releases the pin 223, and the pin 223, driven by the second elastic member 224, is inserted into the slot 211b, thus fixing the position of the second column 212.

[0039] Please refer to the appendix. Figure 4The retraction mechanism includes a pull rod 225, a second cable 226, and a second motor 227. One end of the pull rod 225 is connected to the side of the plug 223 near the receiving hole 222a, and the other end slides through the third support plate 222, extending to the side of the third support plate 222 opposite to the first column 211. The second motor 227 is located on the side of the third support plate 222 opposite to the first column 211 and is connected to the end of the pull rod 225 opposite to the plug 223 via the second cable 226. The remote retraction mechanism of the second motor 227 and the second cable 226 allows the operator to control the status of all column plugs 223 from the ground. Compared with manual climbing to unlock them one by one, remote control unlocking greatly improves unlocking efficiency and eliminates the risks of working at height.

[0040] Please refer to the appendix. Figure 4 The groove wall of the slot 211b near the base 1 extends in the same direction as the movement direction of the plug 223, forming a lower groove wall; the groove opening of the groove wall of the slot 211b away from the base 1 gradually moves away from the base 1, forming an upper groove wall that is inclined towards the extension direction of the slot 211b. The inclined upper groove wall design allows the plug 223 to automatically slide into the bottom of the groove and lock in place under the action of gravity, eliminating the need for precise alignment during installation.

[0041] The specific operation method of this utility model is as follows:

[0042] During installation, the first column 211 is lifted by a lifting tool or manually so that the insert 33 is inserted into the socket 31a. Then, the electromagnet 35 is energized, so that the first rack 34 and the second rack 37 mesh, thus installing the first column 211. The working platform 24 is connected to the first cable 233, and the liquid delivery pipe connecting the oil pump 213 and the liquid storage space is connected. The oil pump 213 delivers liquid from the oil tank 214 to the liquid storage space, which allows the second column 212 to move towards the side away from the base 1, thereby raising the height of the second column 212. Conversely, it lowers the height of the second column 212. After the height of the second column 212 reaches the preset position, the positioning component 22 fixes the position of the second column 212 to complete the height adjustment of the second column 212. During operation, the first motor 232 is used to raise and lower the working platform.

[0043] During disassembly, disconnect the fluid delivery pipe connecting the oil pump 213 and the liquid storage space, separate the work platform 24 from the first cable 233, de-energize the electromagnet 35 to disengage the first rack 34 from the second rack 37, and separate the insert block 33 from the insertion hole 31a to complete the disassembly and assembly of the lifting platform.

[0044] The above are merely preferred embodiments of this utility model and do not limit the patent scope of this utility model. Any equivalent structural transformations made based on the concept of this utility model and the contents of the specification and drawings of this utility model, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this utility model.

Claims

1. A lifting platform for installing and dismantling a gantry crane, characterized in that, The device includes a base and a lifting component mounted on the base. The lifting component includes multiple column assemblies evenly distributed around the base. The column assemblies are detachably connected to the base via a first quick-release assembly. The lifting component also includes a working platform and multiple lifting components for lifting the working platform mounted on the multiple column assemblies. Each lifting component corresponds to each column assembly.

2. The lifting platform for installing and dismantling a gantry crane according to claim 1, characterized in that, The column assembly includes a first column with a recessed sliding hole at one end. The sliding hole extends in the same direction as the first column. A second column is slidably disposed within the sliding hole, with one end of the second column extending out of the sliding hole and the other end located within the sliding hole. The column assembly also includes a moving component for driving the second column to slide within the sliding hole.

3. The lifting platform for installing and dismantling a gantry crane according to claim 2, characterized in that, The moving assembly includes a piston disposed on the second column at the inner end of the sliding hole. The piston is clearance-fitted with the sliding hole. The space between the bottom of the sliding hole and the side of the piston away from the second column forms a liquid storage space for storing liquid. The moving assembly includes an oil tank, an oil pump, and a delivery pipe disposed above the base. The delivery pipe is used to connect the liquid storage space, the oil tank, and the oil pump to each other. The oil pump is used to transport liquid in the oil tank to the liquid storage space through the delivery pipe or to transport liquid in the liquid storage space to the oil tank. The delivery pipe connecting the liquid storage space and the oil pump is detachably connected.

4. The lifting platform for installing and dismantling a gantry crane according to claim 2, characterized in that, The first quick-release assembly includes a first connecting seat fixed above the base. A second connecting seat is provided on the side of the first connecting seat away from the base. The side of the second connecting seat away from the first connecting seat is fixed to the end of the first column away from the sliding hole. A plug is provided on the side of the second connecting seat near the first connecting seat. A socket for insertion is recessed on the side of the first connecting seat near the second connecting seat. A first receiving groove is formed by a horizontal recess on the wall of the socket. An electromagnet is fixed to the bottom of the first receiving groove. A first rack is provided on the side of the electromagnet away from the bottom of the first receiving groove. A second receiving groove is formed by a horizontal recess on the outer wall of the plug. A metal plate is provided in the second receiving groove and movably connected to the bottom of the second receiving groove by a first elastic member. A second rack is provided on the side of the metal plate away from the second receiving groove. The electromagnet is used to attract the metal plate so that the second rack meshes with the first rack. An orienting member is also provided in the second receiving groove to fix the moving direction of the metal plate.

5. The lifting platform for installing and dismantling a gantry crane according to claim 4, characterized in that, The directional component includes a guide rod that is laterally disposed on the side of the metal plate near the bottom of the second receiving groove, and the bottom of the second receiving groove is recessed to form a limiting sliding hole for the guide rod to slide.

6. The lifting platform for installing and dismantling a gantry crane according to claim 2, characterized in that, The lifting assembly includes a first support plate horizontally disposed at one end of the second column away from the first column. A first motor is provided on the first support plate, and the first motor is connected to the work platform through a first cable wound on the output shaft.

7. The lifting platform for installing and dismantling a gantry crane according to claim 3, characterized in that, The moving component also includes a positioning component for fixing the position of the second column within the sliding hole.

8. The gantry crane installation and removal lift of claim 7, wherein, The positioning component includes a second support plate laterally disposed on the outer wall of the second column, the second support plate being located outside the sliding hole. A third support plate is vertically disposed on the side of the second support plate opposite to the second column, the extension direction of the third support plate being parallel to the extension direction of the first column. The third support plate is located outside the first column, and a recessed receiving hole is provided on the side of the third support plate near the first column. A plug is slidably disposed in the receiving hole, and one end of the plug near the bottom of the receiving hole is connected to the receiving hole through a second elastic member. The second elastic member is used to push the end of the plug away from the third receiving hole out of the receiving hole. A plurality of slots for plug insertion are evenly distributed on the side of the outer wall of the first column near the third support plate, and the distribution direction of the plurality of slots is along the extension direction of the first column. The positioning component also includes a retraction member for moving the plug toward the side near the receiving hole and receiving the plug into the receiving hole.

9. The lifting platform for installing and dismantling a gantry crane according to claim 8, characterized in that, The retraction component includes a pull rod, a second pull cable, and a second motor; one end of the pull rod is connected to the side of the plug near the receiving hole, and the other end slides through the third support plate and extends to the side of the third support plate opposite to the first column; the second motor is located on the side of the third support plate opposite to the first column, and is connected to the end of the pull rod opposite to the plug through the second pull cable.

10. The lifting platform for installing and dismantling a gantry crane according to claim 8, characterized in that, The groove wall on the side of the slot closest to the base extends in the same direction as the movement direction of the plug, forming a lower groove wall; the groove opening on the side of the slot away from the base gradually moves away from the base, forming an upper groove wall that slopes towards the extension direction of the slot.

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