CN220242421U

CN220242421U - 3D printer

Info

Publication number: CN220242421U
Application number: CN202321915247.7U
Authority: CN
Inventors: 郭惠勇; 蔡佳雄
Original assignee: Xiamen Yangtuo 3d Technology Co ltd
Current assignee: Xiamen Yangtuo 3d Technology Co ltd
Priority date: 2023-07-20
Filing date: 2023-07-20
Publication date: 2023-12-26
Anticipated expiration: 2033-07-20

Abstract

The utility model relates to a 3D printer, which is used for solving the problems of poor motion stability, easy shaking, uncooled driving and asynchronous driving and the like of a large-size 3D printer in the prior art caused by the characteristics of large area, heavy weight, large inertia and the like of a printing platform. The utility model provides a 3D printer, which comprises a frame, print platform, print the shower nozzle, Y axle device, X axle drive assembly, Z axle drive assembly, lifting frame and synchronous lifting assembly, the frame is connected by bottom frame, top frame and four stands and is formed the cuboid shape, print platform installs on bottom frame, lifting frame sets up in print platform's top, lifting frame's left and right sides is gone up and down by two Z axle drive assembly drive respectively, connect through synchronous lifting assembly between two Z axle drive assemblies, print the shower nozzle and install on lifting frame through Y axle device and drive along Y axle direction back and forth movement by Y axle device, print the shower nozzle and drive along X axle direction left and right movement by X axle drive assembly.

Description

3D printer

Technical Field

The utility model belongs to the technical field of 3D printing, and particularly relates to a 3D printer.

Background

The application field of 3D printing technology is wider and wider, and in particular, fused deposition rapid prototyping (FDM), also called hot melt deposition technology, is becoming more and more popular for scientific research institutions and food enterprises as one of the main 3D printing technologies. The technology is that a hot-melt type material wire is heated and melted by a 3D printer and then extruded from a spray head, deposited on a printing platform or a previous layer of solidified material, and solidified and molded after the temperature is lower than the solidification temperature of the material wire, finally printed into a solid, and a 3D printed product is obtained.

Currently, a 3D printer commonly used in the market generally comprises a printing platform and a printing nozzle, wherein the printing platform is arranged below the printing nozzle and is used for supporting a 3D printing product, and the printing platform generally has two moving modes of lifting up and down along a Z axis and moving back and forth along a Y axis; for example, the application number of the published Chinese patent application is CN202023279696.6, and the Y-axis device of the 3D printer and the 3D printer adopt a moving mode of lifting up and down along a Z-axis, and during printing, the lifting of the printing platform is realized by controlling a Z-axis motor after each layer of printing is completed, but for a large-size 3D printer, the printing platform has the characteristics of heavy weight, large inertia and the like because of the large area, and has the problems of poor motion stability, easy shaking in printing, uncoordinated driving and the like when the printing platform lifts up and down, so that the normal printing and the printing accuracy are affected.

Disclosure of Invention

Aiming at the defects in the prior art, the utility model provides the 3D printer which is reasonable in design, simple in structure, good in driving coordination, stable in installation of a printing platform and not easy to shake.

In order to achieve the above purpose, the present utility model adopts the following technical scheme:

the utility model provides a 3D printer, its includes frame, print platform, print shower nozzle, Y axle device, X axle drive assembly and Z axle drive assembly, the frame is connected by bottom frame, top frame and four stands and is formed the cuboid shape, and it still includes lifting frame and synchronous lifting assembly, print platform installs on bottom frame, and lifting frame sets up in print platform's top, and lifting frame's left and right sides is gone up and down by two Z axle drive assembly drive respectively, connects through synchronous lifting assembly between two Z axle drive assemblies, print shower nozzle passes through Y axle device and installs on lifting frame and drive by Y axle device and follow Y axle direction back and forth movement, print the shower nozzle and drive by X axle drive assembly and follow X axle direction left and right movement.

Preferably, the Z-axis driving assembly comprises a support plate, a Z-axis screw rod, a Z-axis guide rod, a Z-axis driving motor and screw driving belts, wherein the support plate and the Z-axis driving motor are fixedly installed on a lifting frame, the support plate extends back and forth along the Y-axis direction, two ends of the support plate are respectively in threaded connection with the two Z-axis screw rods, a first belt pulley is fixedly sleeved at the upper ends of the two Z-axis screw rods and is in transmission connection with one ends of the two screw driving belts, two second belt pulleys are fixedly sleeved on an output shaft of the Z-axis driving motor and are respectively in transmission connection with the other ends of the two screw driving belts, the lower ends of the two Z-axis screw rods are respectively and rotatably connected to a bottom frame, the two Z-axis guide rods are respectively and movably arranged at two ends of the support plate in a penetrating mode, and the lower ends of the two Z-axis guide rods are respectively and fixedly connected to the bottom frame.

Preferably, the upper end and the lower end of the Z-axis screw rod and the Z-axis guide rod are respectively provided with a Z-axis limiting seat, and the Z-axis limiting seats are fixedly arranged on a reinforcing rod arranged between the bottom frame and the top frame.

Preferably, the synchronous lifting assembly comprises a first synchronous belt and a second synchronous belt, the lower end of each Z-axis screw rod is fixedly sleeved with a synchronous wheel, two ends of the first synchronous belt are respectively in transmission connection with the synchronous wheels on the Z-axis screw rods of which the two Z-axis driving assemblies are positioned at the front ends, and two ends of the second synchronous belt are respectively in transmission connection with the synchronous wheels on the Z-axis screw rods of which the two Z-axis driving assemblies are positioned at the rear ends.

Preferably, the synchronous lifting assembly further comprises tensioning seats and tensioning wheels, the two tensioning seats are respectively arranged on the bottom frame in a corresponding mode to the first synchronous belt and the second synchronous belt, the two tensioning wheels are respectively rotatably arranged on the two tensioning seats, and the first synchronous belt and the second synchronous belt are respectively wound on the outer sides of the two tensioning wheels.

Preferably, the tensioning seat is slidably connected to the bottom frame, and an adjusting bolt is arranged between the tensioning seat and the bottom frame for fixing.

Preferably, the first synchronous belt and the second synchronous belt are both arranged below the printing platform.

Preferably, the Y-axis device comprises a Y-axis belt and a Y-axis driving motor, the two Y-axis belts are respectively rotatably arranged on the left side and the right side of the lifting frame and extend back and forth along the Y-axis direction, the Y-axis driving motor is a double-shaft extending motor, the Y-axis driving motor is fixedly arranged at the front end or the rear end of the lifting frame, two output shafts of the Y-axis driving motor are respectively fixedly sleeved with two third belt pulleys, the two third belt pulleys are respectively in transmission connection with one ends of the two Y-axis belts, an X-axis guide rail is fixedly connected between the two Y-axis belts, and an X-axis sliding seat for installing a printing nozzle is slidably connected on the X-axis guide rail.

Preferably, two Y-axis guide rails extending forwards and backwards along the Y-axis direction are fixedly arranged on the left side and the right side of the lifting frame respectively, two Y-axis sliding seats are connected with the two Y-axis guide rails in a sliding mode respectively, the two Y-axis sliding seats are fixedly connected with the two ends of the X-axis guide rails respectively, and the two Y-axis sliding seats are driven by two Y-axis belts to move forwards and backwards along the Y-axis direction respectively.

Preferably, the X-axis driving assembly comprises an X-axis belt and an X-axis driving motor, the X-axis belt is rotatably arranged on the X-axis guide rail and extends leftwards and rightwards along the X-axis direction, the X-axis sliding seat is driven by the X-axis belt to move leftwards and rightwards along the X-axis direction, the X-axis driving motor is fixedly arranged at one end of the X-axis guide rail, and a fourth belt pulley is fixedly sleeved on an output shaft of the X-axis driving motor and is in transmission connection with one end of the X-axis belt.

Further, it still includes feed mechanism, feed mechanism is including supporting horizontal pole and support pole setting, and two support pole setting intervals set up in one side of top frame, and the top of two support pole setting corresponds and is equipped with two U type bayonet sockets, and the opening of two U type bayonet sockets sets up, supports the both ends of horizontal pole respectively with two U type bayonet sockets joint.

Preferably, the printing platform is slidably connected to the bottom frame and is driven by a telescopic cylinder to slide back and forth along the Y-axis direction.

Preferably, the printing platform is fixedly mounted on the bottom frame.

The utility model adopts the technical proposal and has the following technical effects:

according to the utility model, the printing platform is arranged on the bottom frame in a fixed or back-and-forth sliding manner along the Y-axis direction, and compared with the traditional printing platform of the large-size 3D printer which is lifted up and down along the Z-axis, the printing platform does not need to lift up and down, and can be effectively ensured to be stably supported in the printing process, so that the problems of poor motion stability, easy shaking, inconsistent driving and the like caused by the characteristics of large area, heavy weight, large inertia and the like of the printing platform during lifting up and down are avoided.

The utility model can be used for installing the components such as the printing spray head, the Y-axis device, the X-axis driving component and the like through the additionally arranged lifting frame, so that the printing spray head can move back and forth along the Y-axis direction and move left and right along the X-axis direction under the action of the Y-axis device and the X-axis driving component, and the Z-axis driving component can drive the lifting frame to drive the printing spray head on the lifting frame to lift by driving the two Z-axis driving components on the left and right sides of the lifting frame, thereby realizing three-dimensional movement of the printing spray head above the printing platform so as to finish printing of 3D products.

According to the utility model, the synchronous lifting assembly is additionally arranged, so that the two Z-axis driving assemblies can synchronously lift, thereby improving the synchronism and stability of the lifting frame and the printing spray head on the lifting frame during lifting, avoiding the problems of shaking, uncooled driving or asynchronous printing of the printing spray head, and effectively improving the printing accuracy and printing quality.

Drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the following description will briefly explain the drawings used in the embodiments or the description of the prior art, and the following description will be made with reference to the drawings:

FIG. 1 is a schematic diagram of a front perspective view of a 3D printer according to the present utility model;

FIG. 2 is a schematic view showing a bottom perspective structure of the 3D printer according to the present utility model;

FIG. 3 is a schematic rear perspective view of the print platform and a portion of the frame of the present utility model removed;

FIG. 4 is a schematic view of the structure of the Z-axis drive assembly and the synchronous lifting assembly of the present utility model;

fig. 5 is a schematic structural view of the discharging mechanism of the present utility model.

Detailed Description

The embodiments described below are only some of the embodiments of the present utility model and do not represent all embodiments consistent with the present utility model. Exemplary embodiments will now be described with reference to the accompanying drawings in which:

referring to fig. 1 to 5, the 3D printer of the present utility model includes a frame 10, a printing platform 14, a printing nozzle 15, an X-axis driving assembly 20, a Y-axis device 30, and a Z-axis driving assembly 40, where the frame 10 is connected by a bottom frame 11, a top frame 12, and four columns 13 to form a rectangular body shape, and all the above components may be used in the art; in order to solve the problems of poor motion stability, easy shaking, inconsistent driving and the like when the printing platform 14 is lifted due to the characteristics of large area, heavy weight, large inertia and the like of the printing platform 14 in the prior art, the printing platform 14 is arranged on the bottom frame 11 in an unlifted manner, as one implementation mode, the printing platform 14 can be fixedly arranged on the bottom frame 11 in a conventional fixing mode such as welding, bolts and the like, as another implementation mode, the printing platform 14 can be connected on the bottom frame 11 in a sliding manner and is driven to slide back and forth along the Y-axis direction by adopting a telescopic cylinder in order to conveniently remove the printed 3D product from the frame 10 for unloading; meanwhile, the utility model further adds a lifting frame 50 and a synchronous lifting assembly 60, wherein the lifting frame 50 is arranged above the printing platform 14 and is used for installing the printing spray head 15, the Y-axis device 30, the X-axis driving assembly 20 and other components, the left side and the right side of the lifting frame 50 are respectively driven to lift by the two Z-axis driving assemblies 40, the two Z-axis driving assemblies 40 are connected through the synchronous lifting assembly 60, the printing spray head 15 is arranged on the lifting frame 50 through the Y-axis device 30 and is driven to move back and forth along the Y-axis direction by the Y-axis device 30, and the printing spray head 15 is driven to move left and right along the X-axis direction by the X-axis driving assembly 20.

In this embodiment, through the added lifting frame 50, the printing nozzle 15, the Y-axis device 30, the X-axis driving assembly 20 and other components can be used for installing, the printing nozzle 15 can move back and forth along the Y-axis direction and move left and right along the X-axis direction under the action of the Y-axis device 30 and the X-axis driving assembly 20, through respectively connecting the two Z-axis driving assemblies 40 with the left and right sides of the lifting frame 50 in a transmission manner, the Z-axis driving assembly 40 can drive the lifting frame 50 to drive the printing nozzle 15 thereon to lift, so that the three-dimensional movement of the printing nozzle 15 above the printing platform 14 is realized, so as to perform the printing of 3D products, and through the added synchronous lifting assembly 60, the two Z-axis driving assemblies 40 can perform synchronous lifting, thereby improving the synchronism and stability when the lifting frame 50 and the printing nozzle 15 thereon lift, avoiding the problems of shaking, driving incompatibility or asynchronous printing of the printing nozzle 15 in printing, and the like, and effectively improving the printing accuracy and printing quality.

Referring to fig. 3 or 4, as a preferred embodiment, based on the above structure, the two Z-axis driving assemblies 40 each include a support plate 41, a Z-axis screw 42, a Z-axis guide rod 43, a Z-axis driving motor 44, and a screw driving belt 45, where the support plate 41 and the Z-axis driving motor 44 are fixedly mounted on the lifting frame 50, the support plate 41 extends forward and backward along the Y-axis direction, two ends of the support plate 41 are respectively in threaded connection with the two Z-axis screws 42, the upper ends of the two Z-axis screws 42 are respectively fixedly sleeved with a first belt pulley and one ends of the two screw driving belts 45, the output shaft of the Z-axis driving motor 44 is fixedly sleeved with two second belt pulleys, the two second belt pulleys are respectively in transmission connection with the other ends of the two screw driving belts 45, the lower ends of the two Z-axis screws 42 are respectively and rotatably connected to the bottom frame 11, the two Z-axis guide rods 43 respectively movably penetrate through two ends of the support plate 41, the two Z-axis screws 42 are respectively located between the two Z-axis guide rods 43, and the lower ends of the two Z-axis guide rods 43 are respectively fixedly connected to the bottom frame 11.

Based on the above structure, preferably, the upper and lower ends of the Z-axis screw rod 42 and the Z-axis guide rod 43 are provided with Z-axis limiting seats 46, and the Z-axis limiting seats 46 are fixedly mounted on the reinforcing rod 16 provided between the bottom frame 11 and the top frame 12.

In this embodiment, the lifting frame 50 is connected to the Z-axis screw rod 42 and the Z-axis guide rod 43 through the support plate 41, that is, the screw nut fixedly embedded on the support plate 41 is screwed to the Z-axis screw rod 42, so as to drive the lifting frame 50 and the printing nozzle 15 thereon to lift by driving the screw rod to rotate, and the linear bearing fixedly embedded on the support plate 41 is sleeved on the Z-axis guide rod 43 in a sliding manner, so as to play a role in lifting and guiding; in addition, by setting the number of the Z-axis screws 42 and the number of the Z-axis guide rods 43 of each Z-axis driving assembly 40 to be two, the two Z-axis screws 42 are in transmission connection with the output shaft of one Z-axis driving motor 44 through two screw driving belts 45, so that the synchronism of the two Z-axis screws 42 on the same side in rotation can be effectively improved, and the stability of the lifting frame 50 and the printing nozzle 15 thereon in lifting can be improved.

Referring to fig. 4, as a preferred embodiment, the synchronous lifting assembly 60 includes a first synchronous belt 61 and a second synchronous belt 62, preferably, the first synchronous belt 61 and the second synchronous belt 62 are all disposed below the printing platform 14, a synchronous wheel 63 is fixedly sleeved at the lower end of each Z-axis screw 42, two ends of the first synchronous belt 61 are respectively in transmission connection with the synchronous wheels 63 on the Z-axis screws 42 of the front ends of the two Z-axis driving assemblies 40, and two ends of the second synchronous belt 62 are respectively in transmission connection with the synchronous wheels 63 on the Z-axis screws 42 of the rear ends of the two Z-axis driving assemblies 40.

In the present embodiment, by providing the synchronous lifting assembly 60, when the two Z-axis driving assemblies 40 are used to drive the left and right sides of the lifting frame 50 to lift, the first and second synchronous belts 61 and 62 can be used to improve the synchronism of the rotation of the Z-axis screw 42 on the opposite side, thereby improving the stability of the lifting frame 50 and the printing head 15 thereon when lifting.

On the basis of the above structure, in order to tension the first synchronous belt 61 and the second synchronous belt 62 to ensure the working stability thereof, the synchronous lifting assembly 60 further comprises two tensioning seats 64 and two tensioning wheels 65, the two tensioning seats 64 are respectively mounted on the bottom frame 11 corresponding to the first synchronous belt 61 and the second synchronous belt 62, the two tensioning wheels 65 are respectively rotatably mounted on the two tensioning seats 64, and the first synchronous belt 61 and the second synchronous belt 62 are respectively wound on the outer sides of the two tensioning wheels 65. In order to adjust the tension, the tension seat 64 is further slidably connected to the bottom frame 11, and an adjustment bolt is provided between the tension seat 64 and the bottom frame 11.

Referring to fig. 3, as a preferred embodiment, based on the above structure, the Y-axis device 30 includes two Y-axis belts 31 and a Y-axis driving motor 32, the two Y-axis belts 31 are respectively rotatably mounted on the left and right sides of the lifting frame 50 through Y-axis wheel seats 33 and extend forward and backward along the Y-axis direction, the Y-axis driving motor 32 is a dual-axis motor, the Y-axis driving motor 32 is fixedly mounted on the front end or the rear end of the lifting frame 50, two output shafts of the Y-axis driving motor 32 are respectively fixedly connected with two optical shafts 34 extending left and right along the X-axis direction through a coupling, one ends of the two optical shafts 34 away from the Y-axis driving motor 32 are respectively fixedly sleeved with two third pulleys, the two third pulleys are respectively in transmission connection with one ends of the two Y-axis belts 31, an X-axis guide rail 23 is fixedly connected between the two Y-axis belts 31, and an X-axis slide seat 24 for mounting the printing nozzle 15 is slidingly connected on the X-axis guide rail 23.

On the basis of the above structure, preferably, two Y-axis guide rails 35 extending back and forth along the Y-axis direction are fixedly mounted on the left and right sides of the lifting frame 50, two Y-axis slide carriages 36 are slidably connected to the two Y-axis guide rails 35, the two Y-axis slide carriages 36 are fixedly connected to the two ends of the X-axis guide rail 23, and the two Y-axis slide carriages 36 are driven by two Y-axis belts 31 to move back and forth along the Y-axis direction.

Referring to fig. 3, as a preferred embodiment, the X-axis driving assembly 20 includes an X-axis belt 21 and an X-axis driving motor 22, wherein the X-axis belt 21 is rotatably mounted on an X-axis guide rail 23 through an X-axis wheel seat and extends left and right along the X-axis direction, the X-axis sliding seat 24 is driven by the X-axis belt 21 to move left and right along the X-axis direction, the X-axis driving motor 22 is fixedly mounted at one end of the X-axis guide rail 23, and a fourth belt pulley is fixedly sleeved on an output shaft of the X-axis driving motor 22 and is in transmission connection with one end of the X-axis belt 21.

Referring to fig. 5, as a preferred embodiment, further, in order to discharge the coiled wire material for providing to the printing nozzle 15 based on the above structure, the utility model further includes a discharging mechanism 70, where the discharging mechanism 70 includes a support cross rod 71 and a support upright rod 72, the two support upright rods 72 are spaced apart from each other and arranged on one side of the top frame 12, two U-shaped bayonets 73 are correspondingly arranged on top of the two support upright rods 72, openings of the two U-shaped bayonets 73 are upward, and two ends of the support cross rod 71 are respectively clamped with the two U-shaped bayonets 73.

In this embodiment, after the support cross rod 71 is axially movably passed through the wound wire, two ends of the support cross rod 71 are placed and clamped in the U-shaped bayonets 73 at the top of the two support upright rods 72 from top to bottom, so that the wound wire is rapidly installed.

On the basis of the above structure, the two ends of the supporting cross bar 71 are preferably provided with stoppers 74.

The working principle of the utility model is as follows:

when the wire winding device is used, after the support cross rod 71 is movably arranged along the axial direction and passes through the winding wire, two ends of the support cross rod 71 are placed and clamped in the U-shaped bayonets 73 at the tops of the two support upright rods 72 from top to bottom, and then the wire is pulled to the printing nozzle 15, so that the rapid installation of the winding wire is realized; meanwhile, the printing platform 14 is mounted on the bottom frame 11 in a non-liftable manner;

when in printing, the printing spray head 15 is controlled to move in three dimensions above the printing platform 14 according to the actual situation of the 3D product to be printed, so that the 3D product is printed on the printing platform 14, namely, the two Y-axis belts 31 can be driven to synchronously drive the two Y-axis sliding carriages 36 to slide on the two Y-axis guide rails 35 respectively by controlling the Y-axis driving motor 32 of the Y-axis device 30 to rotate, so as to drive the X-axis guide rail 23 fixedly connected between the two Y-axis belts 31 and the printing spray head 15 connected with the X-axis sliding carriages to slide back and forth along the Y-axis direction, or the X-axis driving motor 22 of the X-axis driving assembly 20 can be controlled to rotate, so as to drive the X-axis belt 21 to drive the X-axis sliding carriage 24 to move left and right along the X-axis direction, so as to drive the printing spray head 15 arranged on the X-axis sliding carriage 24, or the four Z-axis screws 42 rotatably mounted on the left and right sides of the lifting frame 50 can be driven to rotate by controlling the rotation of the Z-axis driving motors 44 of the two Z-axis driving assemblies 40 respectively, the first synchronous belt 61 and the second synchronous belt 62 of the synchronous lifting assembly 60 are utilized to drive the Z-axis screws 42 on the opposite side to synchronously rotate, and one Z-axis driving motor 44 and two screw driving belts 45 of each Z-axis driving assembly 40 are utilized to drive the two Z-axis screws 42 on the same side to synchronously rotate, so that the lifting frame 50 in threaded connection with the Z-axis screws 42 and the printing nozzle 15 thereon are driven to vertically lift along the Z-axis direction, thereby facilitating the printing of the 3D product by the printing nozzle 15 and effectively improving the printing accuracy and the printing quality.

The above is only a preferred embodiment of the present utility model, and is not intended to limit the scope of the present utility model; all equivalent changes, modifications, substitutions and variations on the prior art by logic analysis, reasoning or limited experiments by those skilled in the art, based on the present inventive concept, shall be made within the scope of protection as defined by the claims.

Claims

1. The utility model provides a 3D printer, includes frame, print platform, prints shower nozzle, Y axle device, X axle drive assembly and Z axle drive assembly, the frame is connected by bottom frame, top frame and four stands and is formed rectangular shape, its characterized in that: the printing device is characterized by further comprising a lifting frame and a synchronous lifting assembly, wherein the printing platform is arranged on the bottom frame, the lifting frame is arranged above the printing platform, the left side and the right side of the lifting frame are respectively driven to lift by two Z-axis driving assemblies, the two Z-axis driving assemblies are connected through the synchronous lifting assembly, the printing spray head is arranged on the lifting frame through a Y-axis device and driven to move back and forth along the Y-axis direction by the Y-axis device, and the printing spray head is driven to move left and right along the X-axis direction by the X-axis driving assembly.

2. The 3D printer of claim 1, wherein: the Z-axis driving assembly comprises a supporting plate, Z-axis screw rods, Z-axis guide rods, Z-axis driving motors and screw rod driving belts, wherein the supporting plate and the Z-axis driving motors are fixedly installed on a lifting frame, the supporting plate extends forwards and backwards along the Y-axis direction, two ends of the supporting plate are respectively in threaded connection with the two Z-axis screw rods, a first belt pulley is fixedly sleeved at the upper ends of the two Z-axis screw rods and is in transmission connection with one ends of the two screw rod driving belts, two second belt pulleys are fixedly sleeved on output shafts of the Z-axis driving motors and are respectively in transmission connection with the other ends of the two screw rod driving belts, the lower ends of the two Z-axis screw rods are respectively and rotatably connected to a bottom frame, the two Z-axis guide rods are respectively and movably arranged at two ends of the supporting plate in a penetrating mode, and the lower ends of the two Z-axis guide rods are respectively and fixedly connected to the bottom frame.

3. The 3D printer of claim 2, wherein: the upper end and the lower end of the Z-axis screw rod and the Z-axis guide rod are respectively provided with a Z-axis limiting seat, and the Z-axis limiting seats are fixedly arranged on a reinforcing rod arranged between the bottom frame and the top frame.

4. The 3D printer of claim 1, wherein: the synchronous lifting assembly comprises a first synchronous belt and a second synchronous belt, synchronous wheels are fixedly sleeved at the lower end of each Z-axis screw rod, two ends of the first synchronous belt are respectively in transmission connection with the synchronous wheels on the Z-axis screw rods of the front ends of the two Z-axis driving assemblies, and two ends of the second synchronous belt are respectively in transmission connection with the synchronous wheels on the Z-axis screw rods of the rear ends of the two Z-axis driving assemblies.

5. The 3D printer of claim 4, wherein: the synchronous lifting assembly further comprises tensioning seats and tensioning wheels, the two tensioning seats are respectively arranged on the bottom frame in a corresponding mode to the first synchronous belt and the second synchronous belt, the two tensioning wheels are respectively arranged on the two tensioning seats in a rotating mode, and the first synchronous belt and the second synchronous belt are respectively wound on the outer sides of the two tensioning wheels.

6. The 3D printer of claim 5, wherein: the tensioning seat is connected to the bottom frame in a sliding mode, and an adjusting bolt is arranged between the tensioning seat and the bottom frame for fixation.

7. The 3D printer of claim 1, wherein: the Y-axis device comprises a Y-axis belt and a Y-axis driving motor, the two Y-axis belts are respectively rotatably arranged on the left side and the right side of the lifting frame and extend back and forth along the Y-axis direction, the Y-axis driving motor is a double-shaft extending motor, the Y-axis driving motor is fixedly arranged at the front end or the rear end of the lifting frame, two output shafts of the Y-axis driving motor are respectively fixedly sleeved with two third belt pulleys, the two third belt pulleys are respectively in transmission connection with one ends of the two Y-axis belts, an X-axis guide rail is fixedly connected between the two Y-axis belts, and an X-axis sliding seat for installing a printing nozzle is slidably connected on the X-axis guide rail.

8. The 3D printer of claim 7, wherein: two Y-axis guide rails extending back and forth along the Y-axis direction are fixedly arranged on the left side and the right side of the lifting frame respectively, two Y-axis sliding seats are connected with the two Y-axis guide rails in a sliding mode respectively, the two Y-axis sliding seats are fixedly connected with the two ends of the X-axis guide rails respectively, and the two Y-axis sliding seats are driven by two Y-axis belts to move back and forth along the Y-axis direction respectively.

9. The 3D printer of claim 7, wherein: the X-axis driving assembly comprises an X-axis belt and an X-axis driving motor, the X-axis belt is rotatably arranged on the X-axis guide rail and extends left and right along the X-axis direction, the X-axis sliding seat is driven by the X-axis belt to move left and right along the X-axis direction, the X-axis driving motor is fixedly arranged at one end of the X-axis guide rail, and a fourth belt pulley is fixedly sleeved on an output shaft of the X-axis driving motor and is in transmission connection with one end of the X-axis belt.

10. The 3D printer of claim 1, wherein: the automatic feeding device comprises a top frame, and is characterized by further comprising a feeding mechanism, wherein the feeding mechanism comprises a supporting cross rod and supporting vertical rods, the distance between the two supporting vertical rods is set on one side of the top frame, two U-shaped bayonets are correspondingly arranged at the tops of the two supporting vertical rods, the openings of the two U-shaped bayonets are upward, and the two ends of the supporting cross rod are respectively connected with the two U-shaped bayonets in a clamping mode.