CN217346734U

CN217346734U - 3D printer for large-scale structural part

Info

Publication number: CN217346734U
Application number: CN202222063537.5U
Authority: CN
Inventors: 马智昊
Original assignee: Guangzhou Shangniu Design Co ltd
Current assignee: Guangzhou Shangniu Design Co ltd
Priority date: 2022-08-08
Filing date: 2022-08-08
Publication date: 2022-09-02
Anticipated expiration: 2032-08-08

Abstract

The utility model relates to a 3D prints technical field, discloses a large scale structure 3D printer, and it includes an open framework that all can be adjusted on three directions of length, width and height, and the fixed three supporting legs of group at least that are provided with of bottom surface circumference array of this framework base, the fixed three dead lever that is provided with in top, common slip on the dead lever have cup jointed lifter ring and adjustment mechanism, on the lifter ring, the inboard is equipped with annular air supporting guide rail and cross linear air supporting guide rail, and linear air supporting guide rail's intersection is provided with the air supporting slider, is equipped with servo electric push rod under this air supporting slider, and servo electric push rod's hypomere is equipped with the printing shower nozzle. The utility model discloses a setting is the open framework with adjustable equal on three directions of length, width height, realizes the yardstick extension of shaping structure in the three ascending chi of XYZ to can make the 3D printer print in succession, can satisfy the printing demand of large-scale structure such as cultural intention, architectural design, save printing time, improve printing efficiency.

Description

3D printer for large-scale structural part

Technical Field

The utility model relates to a 3D prints technical field, especially relates to a large scale structure 3D printer.

Background

A3D printer is also called a three-dimensional printer, and is a process for rapid prototyping. The three-dimensional large-scale structural part is manufactured in a layer-by-layer stacking mode, the operation process of the three-dimensional large-scale structural part is similar to that of a traditional printer, only the traditional printer prints ink on paper to form a two-dimensional plane drawing, and the 3D printer realizes layer-by-layer stacking and overlapping of materials such as liquid photosensitive resin materials, molten plastic wires and gypsum powder in a binder spraying or extruding mode to form a three-dimensional entity. At present, the 3D printing technology is widely applied in the industrial field.

However, the existing 3D printer has the following disadvantages when in use: firstly, because the structure and the volume of the printer are fixed, the dimension of the printed and molded structural part is small, generally within 1000x600x500mm, and the molding dimension cannot be expanded in any direction of length, width and height or in three directions according to actual needs, the printing requirements of large-scale components such as large-scale equipment, architectural design, large-scale creative works, large-scale sculpture exhibition works and the like cannot be met; secondly, after the printing of one structural part is finished by the existing 3D printer, the printing of the next structural part can be started only after the structural part is completely taken down, so that the time waste is caused, and the production efficiency is not high; third, current 3D printer lacks the quick cooling device to the structure of printing completion, need rely on external environment (like air conditioner refrigeration) to cool off, leads to large-scale structure to take place the phenomenon of local deformation easily at the printing in-process because cooling rate is inhomogeneous, causes to print fashioned structure intensity and precision and can not reach the requirement.

Therefore, the utility model relates to a new large scale structure 3D printer solves above-mentioned problem.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a large scale structure 3D printer through many-sided structural design with improve in coordination, adopts the open framework that XYZ direction all can be expanded and adjusted to solve the problem that proposes in the above-mentioned background art.

In order to achieve the above object, the utility model provides a following technical scheme:

the utility model provides a large scale structure 3D printer which characterized in that: it includes one kind and all adjustable open framework in three directions of length, width and height, and this framework includes the base, base bottom surface circumference array is fixed and is provided with three supporting legs of group at least, the fixed three dead lever that is provided with in top of base, it is three the dead lever is circumference array setting, and is three the lift ring has been cup jointed in the common slip on the dead lever, be provided with the adjustment mechanism who is used for adjusting the lift ring height on the dead lever, on the lift ring, the inboard is equipped with annular air supporting guide rail and cross sharp air supporting guide rail, and the intersection of this cross sharp air supporting guide rail is provided with the air supporting slider, is equipped with servo electric push rod under this air supporting slider, and servo electric push rod's hypomere is equipped with the printing shower nozzle.

Rotating plates are rotatably sleeved on the three fixing rods, the three rotating plates are arranged in a layered mode, bearing plates are fixedly arranged at the ends, far away from the fixing rods, of the rotating plates, and a positioning mechanism for fixing the rotating plates is arranged on the base; the joints of the air-floating guide rail, the air-floating slide block and the servo electric push rod are also provided with an upper and lower split and detachable protective cover.

Preferably, the adjusting mechanism comprises a fixing ring fixedly sleeved on the outer side surface of the fixing rod, and a telescopic spring is fixedly sleeved on the outer side surface of the fixing rod between the fixing ring and the lifting ring.

Preferably, the outer side surface of the upper half part of the fixing rod is provided with threads, a rocker with a self-locking function is sleeved on the threads, and the rocker is located above the lifting ring.

Preferably, the top surfaces of the three fixing rods are fixedly connected with limiting plates for limiting the lifting ring and the rocker.

Preferably, the positioning mechanism comprises positioning pins which penetrate through the bottom of the base in a sliding mode, the number of the positioning pins is specifically three, the positioning pins correspond to the positions of the fixing rods, and reset springs are fixedly sleeved on the outer side faces of the positioning pins.

Preferably, the rotating plate is provided with two positioning holes matched with the positioning pins, and the two positioning holes are symmetrical about the fixing rod.

Preferably, still be provided with on the loading board and be used for carrying out rapid cooling's cooling body to printing large-scale structure surface, cooling body is including setting up the gasbag ring at the loading board top, the fixed intercommunication in top of gasbag ring has a plurality of air nozzles, rotor plate top fixed mounting has the air-cooler, the output and the gasbag ring of air-cooler pass through the connecting pipe and are connected.

Preferably, the standing groove has been seted up between two parties to the top surface of loading board, gasbag ring fixed connection is at the inner wall of standing groove, and is a plurality of the air nozzle is the circumference array and sets up at gasbag ring top, the air nozzle is the setting of forty-five degree leanin.

Compared with the prior art, the utility model provides a large scale structure 3D printer beneficial effect is:

1. the utility model discloses large-scale structure 3D printer, the structure of its printer, volume are all not fixed, can adjust according to the actual demand when using to produce the 3D printing apparatus of multiple different framework size models. The equipment with the same framework size model is provided with an open framework which can be adjusted in the length, width and height directions, is cooperatively improved through various structural designs, adopts the open framework which can be adjusted in an extensible manner in the XYZ direction, and can be adjusted in a larger scale range according to the size of the dimension of a printed and formed structural part, so that the expansion and adjustment of the forming dimension can be simultaneously carried out in any one direction of the length, the width and the height or in three directions according to the actual forming requirement, and the printing requirements of large-scale components such as large-scale equipment, architectural design, large-scale creative works, large-scale sculpture exhibition works and the like can be met; for example, with a certain type of equipment, printing of structures within 2000x1500x1200mm may be achieved; when the equipment with a larger scale structure is adopted, the printing of the structural member with the size of more than 2000x1500x1200mm can be realized, and the printing spray heads and the like of the core components of the equipment are kept unchanged, so that the expandability of the equipment is greatly improved.

2. The utility model discloses a set up the dead lever of mutually supporting on the base, rotor plate and positioning mechanism, when using, the loading board that will bear the large scale structure of printing the completion rotates 180 degrees, take out fast, then utilize reset spring's reset action, with locating pin tip chucking in the locating hole, thereby realize the rotation and the fixing of loading board, the structure that will print the completion takes off fast, reset fast, print next structure again, make the printing shower nozzle of 3D printer need not to preheat once more and reposition, can print in succession, the time cost is saved, help improving printing efficiency.

3. The utility model discloses a set up the gasbag ring on the loading board, the air nozzle, connecting pipe and air-cooler, at printing the in-process, utilize the air-cooler to carry appropriate amount cold wind, spray to the outside surface of large scale structure through the air nozzle, the outside surface longitudinal flow of printing the structure is only followed to the air current, take away the heat, rapid cooling, do not influence the temperature of printing material mutual faying face, can reach the technological effect by the even cooling of table and inside to the part of having printed the completion, need not to rely on the external environment refrigeration again, it is high because of local temperature to avoid the large scale structure, the phenomenon that cooling shaping speed takes place to warp slowly, help improving and print the shaping quality, improve the intensity of structure.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the prior art descriptions will be briefly described below, it is obvious that the drawings in the following descriptions are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic view of the overall three-dimensional appearance structure of a 3D printer of a large-scale structural member according to an embodiment of the present invention;

fig. 2 is a schematic view of a three-dimensional appearance structure at another view angle of the adjusting mechanism of the 3D printer of the large-scale structural member according to the embodiment of the present invention;

FIG. 3 is a schematic perspective view of the rotating plate, the loading plate and the cooling mechanism according to the embodiment of the present invention;

fig. 4 is an enlarged schematic view of a structure in fig. 1.

Description of the reference numerals:

1. a base; 2. fixing the rod; 3. a lifting ring; 31. an annular air-float guide rail; 4. a fixing ring; 5. a tension spring; 6. a limiting plate; 7. a rocker; 8. printing a spray head; 9. a rotating plate; 10. carrying a plate; 11. positioning pins; 12. a return spring; 13. positioning holes; 14. a balloon ring; 15. an air nozzle; 16. an air cooler; 17. a connecting pipe; 18. an air-float guide rail; 19. an air-floating slide block; 20. a servo electric push rod; 21. a detachable protective cover.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Examples

Please refer to fig. 1, the utility model provides a large-scale structure 3D printer is a large-scale structure 3D printer towards large-scale sculpture, creative works or architectural modeling work printing demand, and its main parameters are as follows: the external dimension is as follows: 3100X1600X3000mm, print supplies: FDM thermoplastic wire; maximum molding size in XYZ direction: 2600X1200X2500mm, operating system: WIN10, print control software: PrintPro, data interface: SLC, network type: an Ethernet network.

Specifically, this large scale structure 3D printer, including an open framework that all can be adjusted on three directions of length, width and height, this framework includes

base

1, and 1 bottom surface circumference array of this base is fixed and is provided with three supporting legs of group to at the fixed anti-skidding rubber backing plate that is provided with in this supporting leg bottom surface, play skid-proof technological effect, thereby improve the holistic stability of printer.

The 3D printer for the large-scale structural part comprises an open framework which is adjustable in three directions of length, width and height, the framework comprises a base 1 made of metal, three groups of supporting legs are fixedly arranged on the bottom surface of the base 1 in a circumferential array mode, three metal fixing rods 2 are fixedly arranged on the top of the base 1, and the three fixing rods 2 are arranged in a circumferential array mode; the three fixing rods 2 are sleeved with lifting rings 3 in a sliding mode, the fixing rods 2 are provided with adjusting mechanisms used for adjusting the heights of the lifting rings 3, and the relative heights (Z-axis dimension) between the lifting rings 3 and the base 1 can be adjusted according to needs through the adjusting mechanisms; an annular air floatation guide rail 31 and a cross-shaped linear air floatation guide rail 18 are arranged on the inner side of the lifting ring 3, the annular air floatation guide rail 31 can take the lifting ring 3 as a support when in work and generates relative motion (generates annular displacement) with the lifting ring 3, and the position of the printing spray head 8 on the XY axis plane direction is changed in the 360-degree direction; the cross-shaped linear air-floating guide rail 18 comprises two (or more) crossed mutually, and is in the same plane or staggered mutually in the Z-axis direction (not shown in the figure); an air-floating slide block 19 is arranged at the intersection of the cross-shaped linear air-floating guide rail 18, a servo electric push rod 20 is arranged right below the air-floating slide block 19, and a printing spray head 8 is arranged at the lower section of the servo electric push rod 20; the servo electric push rod 20 does up-and-down linear motion along the Z-axis direction, and the position of the printing nozzle 8 in the Z-axis direction is adjusted; the crossed cross linear air-floating guide rail 18 is matched with the air-floating slide block 19, the air-floating slide block 19 drives the printing spray head 8 to do reciprocating linear sliding along the cross linear air-floating guide rail 18 (the built-in pore channel of the air-floating slide block 19 covers the cross linear air-floating guide rail 18, the position of the printing spray head 8 in the X, Y axis direction is adjusted together by combining the rotation of the annular air-floating guide rail 31, so that the printing spray head 8 can obtain any position in the X, Y axis direction, thereby completing the printing in the XYZ three directions, the joint of the air-floating guide rail 18, the air-floating slide block 19 and the servo electric push rod 20 is also provided with a vertically split and detachable protective cover 21, and the joint is fixed with each other in a non-working state to provide necessary protection, so as to avoid mutual movement in the transportation or moving process, the protective cover 21 is removed in advance, and one half is taken out upward and the other half is taken out downward.

The three metal fixing rods 2 are all rotatably sleeved with rotating plates 9, the rotating plates 9 are arranged in a layered mode, one ends, far away from the fixing rods 2, of the rotating plates 9 are all fixedly provided with bearing plates 10, and the base 1 is provided with a positioning mechanism used for fixing the rotating plates 9.

In the course of the work, at first adjust the fixed three dead lever 2's that sets up in top of base 1 height, three dead lever 2 is the circumference array setting, and the common slip has cup jointed lifting ring 3 on three dead lever 2, is provided with the adjustment mechanism who is used for adjusting lifting ring 3 height on the dead lever 2, makes the printing shower nozzle 8 that sets up between two parties on the lifting ring 3 reset. When the 3D printer works, firstly, according to the requirement of the forming scale of a structural part, the open framework scale in the three directions of length, width and height is adjusted, the material is loaded and preheated, then, according to the three-dimensional modeling data of the forming structural part, a control computer outputs a printing control instruction to the 3D printer of the large-scale structural part, a driving unit (such as a servo motor) of the 3D printer, an air flotation control device (an air flotation guide rail and an air flotation sliding block) and an electric push rod are used for driving a printing nozzle 8 to respectively move and lift in the XYZ direction, and then, molten printing materials are extruded and output, and the extruded printing materials are cooled and stacked layer by layer, finally, the printing is finished, and the 3D large-scale structural part is formed.

Referring to fig. 1 to 2, the adjusting mechanism with an open architecture includes a fixing ring 4 fixedly sleeved on the outer side surface of the fixing rod 2, and an expansion spring 5 is fixedly sleeved on the outer side surface of the fixing rod 2 between the fixing ring 4 and the lifting ring 3, so that the 3D printer can generate slight vibration when in operation, and the elastic force of the expansion spring 5 can offset the vibration effect, thereby achieving the technical effect of vibration reduction and improving the stability of the printer.

Screw thread and screw thread cup joint have a rocker 7 that has self-locking function to the first half lateral surface of dead lever 2, rocker 7 is located the 3 tops of lifting ring, the equal fixedly connected with in top surface of three dead lever 2 is used for 3 and 7 spacing limiting plates 6 of rocker, the 3D printer is when using, need be according to the height of printing the large-scale structure, adjust the height of lifting ring 3, need revolve wrong rocker 7 this moment, under three group expanding spring 5's supporting role, the realization is fixed to lifting ring 3.

Referring to fig. 3 to 4, the three fixing rods 2 are rotatably sleeved with the rotating plates 9, the three rotating plates 9 are arranged in layers, and the bearing plates 10 are fixedly arranged at the ends of the rotating plates 9 far away from the fixing rods 2, the base 1 is provided with a positioning mechanism for fixing the rotating plate 9, the positioning mechanism comprises positioning pins 11 which penetrate through the bottom of the base 1 in a sliding manner, the number of the positioning pins 11 is three and corresponds to the position of the fixed rod 2, the outer side surface of each positioning pin 11 is fixedly sleeved with a return spring 12, the rotating plate 9 is provided with two positioning holes 13 matched with the positioning pins 11, the two positioning holes 13 are symmetrical about the fixed rod 2, through setting up positioning mechanism, utilize reset spring 12's reset effect, coincide the card of the tip of locating pin 11 and go into locating hole 13 to realize the stable fixed to loading board 10.

The cooling mechanism for rapidly cooling the outer surface of the printed large-scale structural part is arranged on the bearing plate 10 and comprises an air bag ring 14 arranged at the top of the bearing plate 10, a plurality of air nozzles 15 are fixedly communicated with the top of the air bag ring 14, the air nozzles 15 are arranged at the top of the air bag ring 14 in a circumferential array mode, the air nozzles 15 are arranged in a forty-five-degree inward inclination mode, the obliquely arranged air nozzles 15 are just aligned to the outer side surface of the large-scale structural part in printing, so that air blowing cooling is only carried out on the large-scale structural part from the outer side surface, and the temperature of a printing material joint surface is prevented from being influenced; for the printed part, the temperature is uniformly reduced from the outside to the inside through the outer side surface, so that the local deformation of the material is prevented from being influenced.

Rotor plate 9 top fixed mounting has air-cooler 16, the output of air-cooler 16 passes through connecting pipe 17 with gasbag ring 14 and is connected, the standing groove has been seted up between two parties to the top surface of loading board 10, gasbag ring 14 fixed connection is at the inner wall of standing groove, when using, start the work of air-cooler 16, thereby produce a large amount of wind-force, and through air nozzle 15 to the surface blowout and the flow in the large scale structure outside, can realize the inside quick cooling in large scale structure self outside surface, it is too high because of local temperature to reduce the large scale structure, the yardstick structure that pressure inhomogeneous leads to warp, the shaping quality of having improved the component.

The working principle is as follows: firstly, adjusting the open framework dimensions in the length, width and height directions according to the molding dimension requirement of a large-scale structural member, specifically, adjusting the height of a lifting ring 3 according to the height of the large-scale structural member to be printed, synchronously rotating three rocking rods 7 to enable the lifting ring 3 to descend on a fixed rod 2, so as to compress three groups of telescopic springs 5, wherein the telescopic springs 5 generate upward reaction force under the pressure, so that the effect of supporting the lifting ring 3 is achieved, and the height adjustment and fixation of the lifting ring 3 are further realized; the scales in other two directions are adjusted according to the requirement; the printing nozzle 8 is accurately positioned and preheated, printing is carried out under the control of a master control computer, after printing is finished on the bottom supporting surface of the large-scale structural part, the forming volume part in the three directions of XYZ is printed, the air cooler 16 and the 3D printer are started to work synchronously at the moment, each layer of the large-scale structural part is sequentially printed on the outer surface of the large-scale structural part on the upper part of the bearing plate 10 to be cooled, the air cooler 16 works to generate proper amount of cold air (generally 5-15 ℃) and sprays everywhere to the outer surface of the large-scale structural part through the air nozzle 15, and therefore the effects of rapidly cooling, accelerating forming and improving the material bonding strength are achieved.

After printing the large-scale structural part on the bearing plate 10 at the top, the positioning pin 11 on the rotating plate 9 connected with the bearing plate needs to be drawn out downwards, the reset spring 12 is compressed, the bearing plate 10 is rotated by 180 degrees and then the printed large-scale structural part is taken out, the positioning pin 11 is loosened, the reset spring 12 resets to drive the positioning pin 11 to rebound and is clamped into the positioning hole 13, the bearing plate 10 is fixed again, the 3D printer can print the second large-scale structural part on the second layer bearing plate 10 conveniently, the printing nozzle does not need to be repositioned and preheated, continuous printing can be realized, and the required structural part is printed completely.

The utility model discloses an open framework, set up the dead lever on the base, rotor plate and positioning mechanism, when using, the loading board that will bear the large scale structure of printing the completion rotates 180 degrees, take out fast, then utilize reset spring's reset action, with locating pin tip chucking in the locating hole, thereby realize to the rotation of loading board and fix, reset fast, make the printing nozzle of 3D printer can print in succession, need not to preheat again, the time cost is saved, help improving printing efficiency.

The utility model discloses above-mentioned embodiment provides a large scale structure 3D printer, the structure of its printer, volume are all not fixed, can adjust according to the actual demand when using to produce the 3D printing apparatus of multiple different framework size models. The equipment of same framework size model, through setting up the open architecture that all can be adjusted in length, width, height three directions, through many-sided structural design collaborative improvement, adopt the open architecture that all can expand the regulation in XYZ direction, can be according to the size of the structure yardstick of printing the shaping, adjust this framework in the great yardstick range, thereby can be according to the needs of actual shaping in any direction of length, width, height, or carry out the extension of shaping yardstick, adjustment simultaneously in three directions, with can satisfy the individualized or the batch printing shaping needs of large-scale component such as large-scale equipment, architectural design, large-scale literary sketch works, large-scale sculpture exhibition works.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention.

Claims

1. The utility model provides a large scale structure 3D printer which characterized in that: it comprises an open framework which can be adjusted in three directions of length, width and height, the framework comprises a base (1), at least three groups of supporting legs are fixedly arranged on the bottom surface of the base (1) in a circumferential array manner, three fixing rods (2) are fixedly arranged on the top of the base (1), the three fixing rods (2) are arranged in a circumferential array manner, lifting rings (3) are sleeved on the three fixing rods (2) in a sliding manner, the fixed rod (2) is provided with an adjusting mechanism for adjusting the height of the lifting ring (3), the upper and inner sides of the lifting ring (3) are provided with an annular air-float guide rail (31) and a cross-shaped linear air-float guide rail (18), an air-float slide block (19) is arranged at the intersection of the cross-shaped linear air-float guide rail (18), a servo electric push rod (20) is arranged under the air-floating slide block (19), and the lower section of the servo electric push rod (20) is provided with a printing spray head (8).

2. The large scale structure 3D printer of claim 1, wherein: the fixing rod (2) is sleeved with a rotating plate (9) in a rotating mode, the rotating plate (9) is arranged in a layered mode, one end, far away from the fixing rod (2), of the rotating plate (9) is fixedly provided with a bearing plate (10), and a positioning mechanism used for fixing the rotating plate (9) is arranged on the base (1).

3. The large scale structure 3D printer of claim 2, wherein: two positioning holes (13) matched with the positioning pins (11) are formed in the rotating plate (9), and the two positioning holes (13) are symmetrical about the fixing rod (2).

4. The large scale structure 3D printer of claim 2, wherein: the bearing plate (10) is also provided with a cooling mechanism for rapidly cooling the outer surface of the printed large-scale structural part; this cooling body is including fixed gasbag ring (14) that set up at loading board (10) top, the fixed intercommunication in top of gasbag ring (14) has a plurality of air nozzles (15), rotor plate (9) top fixed mounting has air-cooler (16), the output and the gasbag ring (14) of air-cooler (16) are connected through connecting pipe (17).

5. The large scale structure 3D printer of claim 4, wherein: the standing groove has been seted up between two parties to the top surface of loading board (10), gasbag ring (14) fixed connection is in the inner wall of standing groove, and is a plurality of air nozzle (15) are the circumference array and set up at gasbag ring (14) top, air nozzle (15) are the inward slope setting of forty-five degrees.

6. The large scale structure 3D printer of claim 1, wherein: the joints of the air-floating guide rail (18), the air-floating slide block (19) and the servo electric push rod (20) are also provided with a detachable protective cover (21) which is split up and down.

7. The large scale structure 3D printer of claim 1, wherein: the adjusting mechanism further comprises a fixing ring (4) fixedly sleeved on the outer side surface of the fixing rod (2), and an expansion spring (5) is fixedly sleeved on the outer side surface of the fixing rod (2) between the fixing ring (4) and the lifting ring (3).

8. The large scale structure 3D printer of claim 7, wherein: the outer side surface of the upper half part of the fixing rod (2) is provided with threads, a rocker (7) with a self-locking function is sleeved on the threads, and the rocker (7) is located above the lifting ring (3).

9. The large scale structure 3D printer of claim 8, wherein: the top surfaces of the three fixing rods (2) are fixedly connected with limit plates (6) used for limiting the lifting ring (3) and the rocker (7).

10. The large scale structural member 3D printer of claim 2, wherein: the positioning mechanism comprises positioning pins (11) which penetrate through the bottom of the base (1) in a sliding mode, the number of the positioning pins (11) is specifically three, the number of the positioning pins corresponds to the position of the fixing rod (2), and reset springs (12) are fixedly sleeved on the outer side faces of the positioning pins (11).