CN218772462U

CN218772462U - Automatic tool bit pulling device

Info

Publication number: CN218772462U
Application number: CN202222903677.9U
Authority: CN
Inventors: 孙河团
Original assignee: Xiamen Blue Shield Automation Equipment Co ltd
Current assignee: Xiamen Blue Shield Automation Equipment Co ltd
Priority date: 2022-11-02
Filing date: 2022-11-02
Publication date: 2023-03-28
Anticipated expiration: 2032-11-02

Abstract

The utility model relates to a diamond cutter processing field discloses an automatic pull out tool bit device, the load simulator comprises a case, a workbench, vertical plane moving mechanism, pull out tool mechanism, a heater, elevating system and saw bit rotary mechanism, the side top of workstation and quick-witted case sets up relatively, it forms the rotation passageway to have the interval between workstation and the quick-witted case side, elevating system is located quick-witted incasement, the last saw bit fixed rotating shaft that protrudes in the side that quick-witted case is relative with the workstation that is equipped with of elevating system, saw bit fixed rotating shaft is located rotation passageway below, vertical plane moving mechanism fixes on the workstation, pull out tool mechanism fixes on vertical plane moving mechanism, the heater is fixed mutually with the top surface of quick-witted case and workstation, pull out tool mechanism and lie in one side of heater, saw bit rotary mechanism fixes at quick-witted roof portion, the utility model discloses can accomplish the dismantlement on the circular saw bit piece automatically, effectual improvement production efficiency.

Description

Automatic tool bit pulling device

Technical Field

The utility model relates to a diamond cutter processing field, especially an automatic pull out tool bit device.

Background

The diamond cutter has the advantages of extremely high hardness and wear resistance, low friction coefficient, high elastic modulus, high thermal conductivity, low thermal expansion coefficient, small affinity with nonferrous metal and the like. Can be used for the precise processing of non-metal hard and brittle materials such as graphite, high-wear-resistance materials, composite materials, high-silicon aluminum alloy and other tough nonferrous metal materials.

Diamond tool includes disc saw bit and tool bit, and the tool bit passes through the edge of welding strip welding at disc saw bit, and diamond tool is in long-time use, and tool bit wearing and tearing are serious, need pull out the tool bit on the disc saw bit, then weld new tool bit again, and current tool bit replacement method is manual disassembly usually, and the dismantlement process is wasted time and energy, has influenced the change efficiency of tool bit greatly.

SUMMERY OF THE UTILITY MODEL

Therefore, an automatic tool bit pulling device is needed to be provided, and the problems that the tool bit replacement efficiency is low and manual labor and time are wasted on the existing diamond cutter are solved.

In order to achieve the above object, the utility model provides an automatic pull out tool bit device, including quick-witted case, workstation, vertical plane moving mechanism, pull out sword mechanism, heater, elevating system and saw bit rotary mechanism, the side top of workstation and quick-witted case sets up relatively, interval formation rotation channel has between workstation and the quick-witted case side, elevating system is located quick-witted incasement, the last saw bit fixed rotating shaft who protrudes in the side that quick-witted case and workstation are relative that is equipped with of elevating system, saw bit fixed rotating shaft is located the rotation channel below, vertical plane moving mechanism fixes on the workstation, pull out sword mechanism and fix on vertical plane moving mechanism, the heater is fixed mutually with the top surface of quick-witted case and workstation, pull out sword mechanism and be located one side of heater, saw bit rotary mechanism fixes at the quick-witted case top, saw bit rotary mechanism is including rotating motor, action wheel and follow driving wheel lie in the both sides of rotation channel respectively from the driving wheel, the actuating shaft connection of rotating the motor.

Further, vertical plane moving mechanism includes fixed plate, horizontal slide rail, slide, vertical slide rail, horizontal cylinder and vertical cylinder, the fixed plate is vertical to be fixed on the workstation, horizontal slide rail is fixed the fixed plate is towards the side of rotating the passageway, the slide slides and sets up on horizontal slide rail, horizontal cylinder fixes on the side of fixed plate, the output shaft and the slide of horizontal cylinder are connected, vertical slide rail is fixed on the slide, the setting of pulling out the sword mechanism slip is on vertical slide rail, vertical cylinder fixes on the slide, the output shaft and the mechanism of pulling out the sword of vertical cylinder are connected. The cutter pulling mechanism can move in two directions in a vertical plane by the combined pushing of the horizontal cylinder and the vertical cylinder, so that a cutter head on the disc saw blade is pulled out.

Furthermore, the fixed plate and the side of the rotating channel form an included angle. The fixed plate is obliquely arranged with the side edge of the work table, so that the horizontal slide rail and the side edge of the rotating channel have a certain included angle, when the horizontal slide rail drives the cutter pulling mechanism to move, the pulled cutter head can be pushed to the side surface, and the waste cutter head is collected.

Further, the knife pulling mechanism comprises a sliding seat, a connecting block and a pushing and unloading head, the sliding seat is arranged on a vertical sliding rail in a sliding mode, an output shaft of the vertical cylinder is connected with the sliding seat, the connecting block is fixed on the sliding seat, and the pushing and unloading head is arranged at one end, facing the heater, of the connecting block. The push-off head is used for pushing the heated cutter head so as to separate the cutter head from the circular saw blade.

Further, the connecting block comprises a fixing block, an elastic metal sheet and an installation block, the fixing block is fixed with the sliding seat, the top surfaces of the fixing block and the installation block are fixed with the elastic metal sheet, a gap is formed between the fixing block and the installation block, and the push-off head is fixed on one side of the installation block facing the heater.

When the knife pulling mechanism moves downwards and is in contact collision with the disc saw blade, the elastic metal sheet and the gap are arranged to enable the mounting block and the mounting and dismounting head to have certain elasticity, when collision occurs, the elastic metal sheet can play a certain buffering role on the mounting block and the mounting and dismounting head, rigid collision between the mounting block and the mounting and dismounting head and the disc saw blade is avoided, and the use stability and the service life of the device are improved.

Further, the tool pulling mechanism further comprises a cooling water inlet pipe and a cooling water outlet pipe, a cooling cavity is arranged in the mounting block, and the cooling water inlet pipe and the cooling water outlet pipe are communicated with the cooling cavity.

Because the mounting block and the mounting and dismounting head fixed by the mounting block are close to the heating device, when the heating device heats the welding position of the cutter head on the circular saw blade, high-temperature heating is needed, the mounting block is easy to absorb and conducts heat to other parts of the cutter pulling mechanism and the vertical plane moving mechanism, so that the normal use of the device is influenced, the mounting block can be fully cooled due to the arrangement of the cooling water pipe, the heat of the heater is prevented from being conducted to the cutter pulling mechanism and the vertical plane moving mechanism, and the normal operation of the device is ensured.

Further, still including tool setting locating component, tool setting locating component is located heating device and is close to the side of pulling out the sword device, tool setting locating component is photoelectric switch, including photoelectric switch transmitting terminal and photoelectric switch receiving terminal, photoelectric switch transmitting terminal and photoelectric switch receiving terminal are fixed respectively at the both sides limit that rotates the passageway.

The setting of tool setting locating component makes the dead knife mechanism carry out accurate location with the disc saw bit, guarantees that the dead knife mechanism can be accurate unload the tool bit on the disc saw bit.

Further, elevating system includes elevator motor, speed reducer, chain, fixed pivot and lifting support, elevator motor and fixed pivot are fixed respectively in quick-witted incasement portion's bottom and top, speed reducer and elevator motor's output shaft, the chain is around forming the ring through fixed pivot and elevator motor's output shaft, lifting support is connected with one side of chain, saw bit fixed pivot is fixed on lifting support.

The lifting motor drives the annular chain to rotate through the speed reducer, and the lifting support can be driven to lift due to the fact that the lifting support is fixed with the chain, the fixed rotating shaft of the saw blade follows the lifting support to lift, the position of the saw blade is adjusted, and when the disc saw blade is installed on the fixed rotating shaft of the saw blade, the high point position of the disc saw blade can be adjusted through the lifting mechanism, and the tool bit on the disc saw blade is conveniently pulled out through the tool pulling mechanism.

Further, elevating system still includes spacing stand, be equipped with the sleeve on the side of lifting support, the sleeve cover is established on spacing stand. The limiting upright column is used for ensuring the stable vertical lifting of the lifting support.

The technical scheme has the following beneficial effects:

the utility model discloses in, vertical plane mobile device can drive the knife-pulling mechanism and remove in the top that rotates the passageway, the fixed pivot of saw bit is used for fixed saw bit, saw bit rotary mechanism's action wheel and from the tight saw bit of driving wheel clamp, when rotating the motor and rotating, can drive the saw bit and rotate, the heater heats the welding department of tool bit on to the circular saw blade and dissolves, knife-pulling mechanism is under vertical plane mobile device's drive, can fast effectually lift off the tool bit on the circular saw blade from the circular saw blade, thereby accomplish automatic dismantlement of tool bit on the circular saw blade, compare in artifical the dismantlement, the effectual dismantlement efficiency that improves the tool bit, and the production efficiency is improved.

Drawings

Fig. 1 is a front view of an automatic bit extracting apparatus according to an embodiment.

Fig. 2 is a structural view of the vertical plane moving mechanism on the workbench according to the embodiment.

Fig. 3 is a structural diagram of a blade pulling mechanism according to an embodiment.

Fig. 4 is a structural view of an elevating mechanism inside a cabinet according to an embodiment.

FIG. 5 is a side view of the housing, table, blade rotation mechanism and blade in accordance with an embodiment.

Description of reference numerals:

1. a chassis; 11. a rotation channel; 12. the saw blade fixes the rotating shaft;

2. a work table;

3. a vertical plane moving mechanism; 31. a fixing plate; 32. a horizontal slide rail; 33. a slide plate; 34. a vertical slide rail; 35. a horizontal cylinder; 36. a vertical cylinder;

4. a knife pulling mechanism; 41. a sliding seat; 42. connecting blocks; 421. a fixed block; 422. a resilient metal sheet; 423. mounting blocks; 424. a gap; 43. pushing the head; 44. cooling the water inlet pipe; 45. cooling the water outlet pipe;

5. a heater;

6. a lifting mechanism; 61. a lifting motor; 62. a chain; 63. fixing the rotating shaft; 64. a lifting support; 65. a limiting upright post; 66. a sleeve; 67. a speed reducer;

7. a tool setting positioning component; 71. a photoelectric switch transmitting terminal; 72. a photoelectric switch receiving end;

8. a saw blade rotating mechanism; 81. rotating the motor; 82. a driving wheel; 83. a driven wheel.

Detailed Description

To explain technical contents, structural features, and objects and effects of the technical solutions in detail, the following detailed description is given with reference to the accompanying drawings in conjunction with the embodiments.

Referring to fig. 1-5, the embodiment discloses an automatic tool bit pulling device, which includes a case 1, a workbench 2, a vertical plane moving mechanism 3, a tool pulling mechanism 4, a heater 5, an elevating mechanism 6, and a saw blade rotating mechanism 8, wherein the tops of the sides of the workbench 2 and the case 1 are arranged oppositely, a rotating channel 11 is formed between the workbench 2 and the side of the case 1 at intervals, the elevating mechanism 6 is located in the case 1, the elevating mechanism 6 is provided with a saw blade fixing rotating shaft 12 protruding from the side of the case 1 opposite to the workbench 2, and the saw blade fixing rotating shaft 12 is located below the rotating channel 11.

The vertical plane moving mechanism 3 is fixed on the workbench 2, the knife pulling mechanism 4 is fixed on the vertical plane moving mechanism 3, the heater 5 is fixed with the top surfaces of the case 1 and the workbench 2, and the knife pulling mechanism 4 is positioned on one side of the heater 5.

In this embodiment, the heater 5 is a heating wire bent into an inverted U shape, and the heating wire crosses the rotating passage 11.

The lifting mechanism 6 comprises a lifting motor 61, a speed reducer 67, a chain 62, a fixed rotating shaft 63, a lifting support 64 and a limiting upright post 65, the lifting motor 61 and the fixed rotating shaft 63 are respectively fixed at the bottom and the top of the interior of the case 1, the speed reducer 67 is connected with an output shaft of the lifting motor 61, the chain 62 winds the output shafts of the fixed rotating shaft 63 and the speed reducer 67 to form a ring, the lifting support 64 is connected with one side of the chain 62, the saw blade fixed rotating shaft 12 is fixed on the lifting support 64, a sleeve 66 is arranged on the side edge of the lifting support 64, and the sleeve 66 is sleeved on the limiting upright post 65. The limit post 65 is used for ensuring stable vertical lifting of the lifting support 64.

Lifting motor 61 drives annular chain 62 and rotates, because lifting support 64 is fixed mutually with chain 62, therefore can drive lifting support 64 and go up and down to adjust the position of saw bit fixed rotating shaft 12, when the disc saw bit is installed on saw bit fixed rotating shaft 12, can adjust the high point position of disc saw bit through elevating system 6, conveniently pull out the tool bit on the disc saw bit of sword mechanism 4 extraction.

In this embodiment, two spacing upright posts 65 are arranged in two, and two upright posts are arranged in two sides, and the side of the machine case 1 facing the workbench 2 is an open side, so that the worker can observe the operation condition of the lifting mechanism 6 conveniently, and the maintenance is also facilitated, and the outer side edge of the lifting support 64 is provided with a baffle saw blade fixing rotating shaft 12 which penetrates through the baffle.

Vertical plane moving mechanism 3 includes fixed plate 31, horizontal slide rail 32, slide 33, vertical slide rail 34, horizontal cylinder 35 and vertical cylinder 36, fixed plate 31 is vertical to be fixed on workstation 2, horizontal slide rail 32 is fixed at fixed plate 31 towards the side of rotating-path 11, slide 33 slides and sets up on horizontal slide rail 32, horizontal cylinder 35 is fixed on the side of fixed plate 31, the output shaft and the slide 33 of horizontal cylinder 35 are connected, vertical slide rail 34 is fixed on slide 33, the setting of sliding of tool setting 4 is on vertical slide rail 34, vertical cylinder 36 is fixed on slide 33, the output shaft and the tool setting 4 of tool setting are pulled out to vertical cylinder 36 are connected. The combined pushing of the horizontal cylinder 35 and the vertical cylinder 36 enables the knife pulling mechanism 4 to perform bidirectional movement in a vertical plane, so as to pull out the knife head on the disc saw blade.

The fixing plate 31 is angled with respect to the side of the rotation channel 11. The fixed plate 31 and the side of the work bench are inclined, so that the horizontal slide rail 32 and the side of the rotary channel 11 have a certain included angle, and when the horizontal slide rail 32 drives the knife pulling mechanism 4 to move, the pulled knife head can be pushed to the side, so that the waste knife head can be collected.

In this embodiment, the included angle is 0-90 °, and a collection bin can be designed on the side surface of the workbench 2 facing the rotating channel 11, and is used for collecting the extracted waste gas cutter head.

The tool drawing mechanism 4 comprises a sliding seat 41, a connecting block 42 and a pushing and unloading head 43, the sliding seat 41 is arranged on the vertical sliding rail 34 in a sliding mode, an output shaft of the vertical cylinder 36 is connected with the sliding seat 41, the connecting block 42 is fixed on the sliding seat 41, and the pushing and unloading head 43 is arranged at one end, facing the heater 5, of the connecting block 42. The ejector 43 is used to push the heated blade and thereby to disengage the blade from the circular saw blade.

Specifically, the connecting block 42 includes a fixing block 421, an elastic metal piece 422 and an installation block 423, the fixing block 421 is fixed to the sliding seat 41, the top surfaces of the fixing block 421 and the installation block 423 are fixed to the elastic metal piece 422, a gap 424 is formed between the fixing block 421 and the installation block 423, and the push-off head 43 is fixed to one side of the installation block 423 facing the heater 5.

When the knife pulling mechanism 4 moves downwards and is in contact with and collides with the disc saw blade, the elastic metal sheets 422 and the gaps 424 are arranged to enable the mounting blocks 423 and the mounting and dismounting heads to have certain elasticity, when collision occurs, the elastic metal sheets 422 can play a certain buffering role on the mounting blocks 423 and the mounting and dismounting heads, hard collision between the mounting blocks 423 and the mounting and dismounting heads and the disc saw blade is avoided, and the use stability and the service life of the device are improved.

In this embodiment, the fixing block 421 and the mounting block 423 are made of metal alloy materials, the mounting head is a tungsten steel head, which has high strength and rigidity, and the sliding seat 41, the fixing block 421, the elastic metal piece 422, the mounting block 423, and the mounting head are fixed by screws.

The cutter pulling mechanism 4 further comprises a cooling water inlet pipe 44 and a cooling water outlet pipe 45, a cooling cavity is arranged in the mounting block 423, and the cooling water inlet pipe 44 and the cooling water outlet pipe 45 are communicated with the cooling cavity.

Because the mounting block 423 and the mounting and dismounting head fixed by the mounting block 423 are close to the heating device, when the heating device heats the welding position of the cutter head on the circular saw blade, high-temperature heating is needed, the mounting block 423 can easily absorb and conduct heat on the rest parts of the cutter pulling mechanism 4 and the vertical plane moving mechanism 3, and therefore normal use of the device is affected, the mounting block 423 can be fully cooled due to the arrangement of the cooling water pipe, the heat of the heater 5 is prevented from being conducted to the cutter pulling mechanism 4 and the vertical plane moving mechanism 3, and normal operation of the device is guaranteed.

In this embodiment, the automatic tool bit pulling device further includes a tool setting positioning assembly 7, the tool setting positioning assembly 7 is located at a side of the heating device close to the tool pulling device, the tool setting positioning assembly 7 includes a photoelectric switch transmitting end 71 and a photoelectric switch receiving end 72, and the photoelectric switch transmitting end 71 and the photoelectric switch receiving end 72 are respectively fixed at two side edges of the rotating channel 11.

The setting of tool setting locating component 7 makes the dead knife mechanism 4 and disc saw piece carry out accurate location, guarantees that dead knife mechanism 4 can be accurate unload the tool bit on the disc saw piece.

In this embodiment, the case 1 may be provided with a console, a program is embedded in the console, and the console, the motor, the cylinder, the photoelectric switch transmitting terminal 71 and the photoelectric switch receiving terminal 72 in this embodiment are connected to the console, so as to effectively control the stable operation of the whole apparatus.

The saw blade rotating mechanism 8 is fixed on the top of the case 1, the saw blade rotating mechanism 8 comprises a rotating motor 81, a driving wheel 82 and a driven wheel 83, the driving wheel 82 and the driven wheel 83 are respectively located on two sides of the rotating channel 11, and a driving shaft of the rotating motor 81 is connected with the driving wheel 82.

When the embodiment is used:

the disc saw blade of the diamond cutter with the seriously worn cutter head is fixed on the saw blade fixing rotating shaft 12, the lifting motor 61 rotates to drive the chain 62 to rotate, so that the lifting support 64 drives the saw blade 12 on the lifting support to be lifted for a certain distance, the disc saw blade is positioned in the rotating channel 11 at the moment, the driving wheel 82 and the driven wheel 83 of the saw blade rotating mechanism 8 are clamped on two sides of the disc saw blade, the top end of the disc saw blade protrudes out of the top surfaces of the workbench 2 and the case 1, the heater 5 just can heat the welding position of the cutter head on the disc saw blade, when the welding position on the cutter head is heated for a certain time, the rotating motor 81 rotates to move the heated cutter head to the side edge of the heater 5, the next cutter head continues to be heated, meanwhile, the horizontal cylinder 35 and the vertical cylinder 36 of the vertical plane moving mechanism 3 work in a matching mode, the push-off head 43 moves to the side edge of the heated cutter head, the horizontal cylinder 35 contracts, the push-off head 43 pushes the cutter head to unload the cutter head, when the device works, the device, the cooling water inlet pipe 44 and the cooling water outlet pipe 45 simultaneously feed water, the mounting block is fully cooled, and the normal operation of the device is guaranteed.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or terminal that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or terminal. Without further limitation, an element defined by the phrases "comprising 8230; \8230;" or "comprising 8230; \8230;" does not exclude the presence of additional elements in a process, method, article, or terminal device that comprises the element. Further, herein, "greater than," "less than," "more than," and the like are understood to exclude the present numbers; the terms "above", "below", "within" and the like are to be understood as including the present number.

Although the embodiments have been described, once the basic inventive concept is known, other changes and modifications can be made to the embodiments by those skilled in the art, so that the above embodiments are only examples of the present invention, and not intended to limit the scope of the present invention, and all the modifications of the equivalent structure or equivalent flow path using the contents of the specification and the drawings of the present invention, or directly or indirectly using other related technical fields are also included in the scope of the present invention.

Claims

1. The utility model provides an automatic tool bit pulling device, its characterized in that, includes quick-witted case, workstation, vertical plane moving mechanism, tool bit pulling mechanism, heater, elevating system and saw bit rotary mechanism, the side top of workstation and quick-witted case sets up relatively, interval formation rotation passageway has between workstation and the quick-witted case side, elevating system is located quick-witted incasement, the last saw bit fixed rotating shaft that protrudes in quick-witted case and the relative side of workstation that is equipped with of elevating system, saw bit fixed rotating shaft is located rotation passageway below, vertical plane moving mechanism fixes on the workstation, tool bit pulling mechanism fixes on vertical plane moving mechanism, the heater is fixed mutually with the top surface of quick-witted case and workstation, tool bit pulling mechanism is located one side of heater, saw bit rotary mechanism fixes at quick-witted case top, saw bit rotary mechanism is including rotating motor, action wheel and follow driving wheel are located rotation passageway's both sides respectively, the action wheel is connected to the drive shaft of rotation motor.

2. The automatic tool bit drawing device of claim 1, wherein the vertical plane moving mechanism comprises a fixed plate, a horizontal slide rail, a slide plate, a vertical slide rail, a horizontal cylinder and a vertical cylinder, the fixed plate is vertically fixed on the workbench, the horizontal slide rail is fixed on the side surface of the fixed plate facing the rotating channel, the slide plate is slidably arranged on the horizontal slide rail, the horizontal cylinder is fixed on the side surface of the fixed plate, the output shaft of the horizontal cylinder is connected with the slide plate, the vertical slide rail is fixed on the slide plate, the tool bit drawing mechanism is slidably arranged on the vertical slide rail, the vertical cylinder is fixed on the slide plate, and the output shaft of the vertical cylinder is connected with the tool bit drawing mechanism.

3. The automatic bit extracting apparatus of claim 2, wherein the retaining plate is angled with respect to the side of the rotational channel.

4. The automatic tool bit drawing device of claim 2, wherein the tool drawing mechanism comprises a sliding seat, a connecting block and a pushing head, the sliding seat is slidably arranged on a vertical sliding rail, the output shaft of the vertical cylinder is connected with the sliding seat, the connecting block is fixed on the sliding seat, and the pushing head is arranged at one end of the connecting block, which faces the heater.

5. The automatic bit drawing device of claim 4, wherein the connecting block comprises a fixing block, an elastic metal sheet and a mounting block, the fixing block is fixed to the sliding seat, the top surfaces of the fixing block and the mounting block are fixed to the elastic metal sheet, a gap is formed between the fixing block and the mounting block, and the push-off head is fixed to the side, facing the heater, of the mounting block.

6. The automatic bit drawing device of claim 5, wherein the bit drawing mechanism further comprises a cooling water inlet pipe and a cooling water outlet pipe, a cooling cavity is arranged in the mounting block, and the cooling water inlet pipe and the cooling water outlet pipe are communicated with the cooling cavity.

7. The automatic tool bit pulling device of claim 1, further comprising a pair of tool positioning components, wherein the pair of tool positioning components are located at the side edge of the heating device close to the tool pulling device, the pair of tool positioning components are photoelectric switches and comprise photoelectric switch transmitting ends and photoelectric switch receiving ends, and the photoelectric switch transmitting ends and the photoelectric switch receiving ends are respectively fixed at the two side edges of the rotating channel.

8. The automatic bit pulling apparatus of claim 1, wherein the elevating mechanism comprises an elevating motor, a speed reducer, a chain, a fixed shaft, and an elevating bracket, the elevating motor and the fixed shaft are fixed at the bottom and the top of the inside of the cabinet, respectively, the speed reducer is connected to an output shaft of the elevating motor, the chain is formed in a ring shape around the fixed shaft and an output shaft of the speed reducer, the elevating bracket is connected to one side of the chain, and the saw blade fixed shaft is fixed to the elevating bracket.

9. The automatic bit pulling device as claimed in claim 8, wherein the lifting mechanism further comprises a limiting column, and a sleeve is arranged on the side edge of the lifting support and sleeved on the limiting column.