CN112223741A

CN112223741A - Constant temperature's jumbo size print platform 3D printing device in space

Info

Publication number: CN112223741A
Application number: CN202010886197.9A
Authority: CN
Inventors: 赵建华; 张海强; 杜俊斌; 陈晓佳
Original assignee: Guangzhou Electronic Technology Co Ltd
Current assignee: Guangzhou Electronic Technology Co Ltd
Priority date: 2020-08-28
Filing date: 2020-08-28
Publication date: 2021-01-15

Abstract

The invention discloses a large-size printing platform 3D printing device with constant space temperature, which comprises a device frame, wherein a heat insulation layer is arranged on the inner side of the frame, a front door is arranged on the front side of the frame, a forming space is formed by the heat insulation layer and a cavity surrounded by the inner part of the front door, a printing platform assembly, a spray head assembly and a hot air double-circulation space heating assembly are arranged in the forming space, the printing platform assembly is arranged at the bottom in the forming space, an air inlet of the hot air double-circulation space heating assembly is arranged at the top of the forming space, and an air outlet of the hot air double-circulation space heating assembly is arranged under the; the hot bed of the printing platform assembly comprises a plurality of hot bed units which are spliced, and each hot bed unit is provided with a horizontal adjusting assembly and a locking assembly. The invention can effectively avoid the stress deformation of the large-size hot bed when the large-size hot bed is heated, and the hot air blown out from the forming space is spread to the periphery, so that the whole forming space is uniformly filled with the hot air, and the forming precision and the surface quality of the product are effectively improved.

Description

Constant temperature's jumbo size print platform 3D printing device in space

Technical Field

The invention relates to the technical field of rapid prototyping equipment, in particular to a large-size printing platform 3D printing device with constant space temperature.

Background

The 3D printer based on the melt accumulation rapid forming process uses plastic filament materials with the diameter of about 1-2 mm, the plastic filament materials are melted and extruded into thin filaments with the diameter of about 0.2-0.4 mm through a printing extrusion head controlled by a computer, and the thin filaments are scanned, printed and accumulated layer by layer to form a three-dimensional object. The forming space of the 3D printer is the printing space of the 3D printer, the 3D printing technology develops towards the direction of the high-precision and large-size printer, the stability of horizontal adjustment of the large-size printing platform and the temperature control of the forming space are very important determining factors of the stability and the precision of the printer in working, and the forming space is a technical difficulty which needs to be solved in the development of the high-precision and large-size printer.

The horizontal adjustment precision and the forming space temperature control of the printing platform of the 3D printer have very important influences on the mechanical property and the forming precision of a printed three-dimensional object. The 3D printer of the fusion stacking rapid forming process uses plastic wires with the diameter of about 1-2 mm, the plastic wires are fused and extruded into thin wires with the diameter of about 0.2-0.4 mm through a printing extrusion head controlled by a computer, and the thin wires are scanned, printed and stacked layer by layer on a printing platform to form a three-dimensional object. The small-size printing platform is high in horizontal precision control degree, but the horizontal adjustment precision of the printing platform of the large-size printer is an important technical difficulty, the horizontal adjustment precision of the printing platform directly affects the printing precision, the printing platform is horizontally unstable, so that a nozzle is far away from or extrudes the printing platform in the printing process of the printer, the printing platform is far away from the nozzle, so that materials cannot be adhered to the platform, and a model is cracked or even broken; the printing platform is too close to the nozzle, the nozzle can be extruded, the nozzle cannot produce threads, and the printing model has wrinkles, even is pushed down and fails to print. Deformation of the printing platform and stress deformation of the material are both large-size printing platform scientific researches, and attempts are made on various materials and various structural designs, so that the horizontal adjustment precision of the printing platform is an important factor of the printing precision of the printer. The melting accumulation rapid forming printing forming process can generate two phase change processes, wherein the first process is that the material is heated and melted into a molten state from a solid filament shape, and the second process is that the material is cooled and solidified into a solid state after being extruded from the molten state through a nozzle. The volume shrinkage during solidification produces internal stresses that can cause warpage of the sample. The temperature of the forming space can influence the size of the internal stress of the sample plate of the formed part, the temperature of the printing forming space rises, the thermal motion energy of the macromolecular chain in the product is higher on one hand, and the intermolecular distance is increased due to volume expansion and the activity space of the macromolecular chain is increased on the other hand, so that the relaxation process is accelerated, the internal stress of the product is reduced, and correspondingly, the generated warping degree is also reduced. However, the ambient temperature must not be too high, otherwise the surface of the part may wrinkle, and "collapse" and "stringing" may occur for parts with small cross-sections. On the other hand, if the temperature of the printing environment is too low, the quenching of the filaments extruded from the nozzle increases the internal stress of the molded part, which easily causes the warping deformation of the part, affects the smooth printing process, and causes the infirm adhesion between layers and the tendency of cracking of the part. Therefore, only the proper printing environment temperature can ensure that the formed product has smaller warping degree, better surface quality and improved forming precision.

The existing printing platform has two schemes: the first type is an adjustable and elastic printing platform, the flatness of the working surface of the printing platform is adjusted through four points, the deformation of the printing platform is compensated through the elasticity of a spring, but for a large-size printing platform, the flatness of the working surface of the printing platform cannot be compensated through the adjustment of the four points; the second type is fixed type print platform, is through the fixed print platform of structure direct locking, need not to adjust the levelness again after fixed, assurance printing accuracy that can be better, but this scheme is only applicable to very small-size print platform, and large-size print platform can increase its deformation on the contrary through fixed scheme. The molding space constant temperature device has two existing space heating schemes: the first is that the printing platform is heated and the forming space is not heated. The second is that the printing platform is heated integrally, and the forming space is provided with a heating device. The first heating mode is through heating printing platform, can make the printing platform surface reach preset the temperature and keep printing platform constant temperature, printing platform heat radiation heating shaping space, this scheme can only guarantee printing platform surface constant temperature, can not guarantee the even and constant temperature of temperature in shaping space, along with the increase of the model printing number of piles, the model printing face is far away from printing platform surface, also big more with the difference in temperature on printing platform surface, thereby can lead to the increase of the model internal stress change of printing to arouse the limit that sticks up or middle fracture of part, lead to printing failure. The second scheme is that the whole forming space is heated, the hot air and the cold air of a heating system are uneven, and particularly, the initial layer section on a printing platform is heated excessively due to uneven temperature of the space in the printing process to cause softening, deformation, cracking and the like to influence the printing precision of the model, and even cause printing failure.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a large-size printing platform 3D printing device with constant space temperature.

In order to achieve the purpose, the technical scheme of the invention is as follows:

a large-size printing platform 3D printing device with constant space temperature comprises a device frame, wherein a three-axis movement mechanism is arranged on the frame, a heat insulation layer is arranged on the inner side of the frame, a front door is arranged on the front side of the frame, the heat insulation layer and a cavity surrounded by the inner part of the front door form a forming space, a printing platform assembly, a spray head assembly and a hot air double-circulation space heating assembly are arranged in the forming space, the spray head assembly is arranged in the forming space through the three-axis movement mechanism, the printing platform assembly is arranged at the bottom in the forming space, an air inlet of the hot air double-circulation space heating assembly is arranged at the top of the forming space, and an air outlet of the hot air double-circulation space heating assembly is;

the printing platform subassembly includes hot bed subassembly, hot bed fixed plate and is used for connecting the print platform support of fixed hot bed fixed plate, the hot bed subassembly is including hot bed glass, combination hot bed and the hot bed hot plate that stacks in proper order from top to bottom, the bottom at the shaping space is fixed to the print platform leg joint, the combination hot bed includes that a plurality of hot bed units splice to form, all is equipped with at least two sets of print platform horizontal adjustment subassemblies and at least a set of print platform locking Assembly on every hot bed unit. According to the arrangement, the large-size printing platform is split into the plurality of hot bed units, the levelness of each hot bed unit is independently adjusted and locked and fixed, the planeness of the large-size printing platform is improved, the platform does not need to be leveled again after being locked and fixed once during leveling, the operation is simplified, and the efficiency is improved.

Further, the hot bed heating plate separately heats the hot bed units according to the positions and the number of the hot bed units.

Further, the heating plate of the hot bed is covered with a heating cover of the hot bed.

Further, print platform horizontal adjustment subassembly includes adjusting bolt, lock nut, adjusting nut, spring base and adjusting spring, adjusting bolt runs through spring base, and its tip is connected with the bottom of hot bed subassembly, spring base sets up the top surface at the hot bed fixed plate, adjusting spring's both ends respectively with spring base and the bottom surface of hot bed hot plate offset, adjusting nut and adjusting bolt threaded connection to support the bottom surface at the hot bed fixed plate, lock nut and adjusting bolt threaded connection and support the bottom at adjusting nut.

Further, print platform locking Assembly includes fixing bolt and two fixed lock nut, fixing bolt runs through hot bed fixed plate and hot bed hot plate in proper order, and its tip offsets with the bottom of hot bed unit, and two fixed lock nuts set up respectively at the top surface and the bottom surface of hot bed fixed plate.

Furthermore, a sliding fit structure of the hot bed is arranged between the two connected hot bed units, the sliding fit structure of the hot bed comprises a convex block convexly arranged on the side surface of the edge of one hot bed unit and a concave groove concavely arranged on the side surface of the edge of the other hot bed unit and matched with the convex block in shape, and a sliding fit gap is reserved between the connected hot bed units through the connection of the sliding fit structure of the hot bed.

Further, the shape of the lug is semicircular.

Furthermore, the hot air double-circulation space heating assembly comprises thermal circulation assemblies symmetrically arranged on two sides of the forming space, each thermal circulation assembly comprises an air guide channel, a heating device and an axial flow fan, an air inlet of each air guide channel is arranged on the upper portion of the forming space and is opposite to the middle of the forming space, an air outlet of each air guide channel is arranged on the lower portion of the forming space and is opposite to the bottom of the printing platform assembly, air enters the air guide channels from the air inlets, sequentially passes through the heating devices and the axial flow fans and finally is blown out from the air outlets. By the arrangement, heated hot air can be more uniformly filled in the printing area of the printing platform, and the phenomena that the hot air outlet is over the printing area and the bottom of the printing model is heated by the hot air of the hot air inlet for a long time to cause local heating and softening, deformation, cracking and even printing failure are avoided.

Furthermore, the part of the air guide channel extends out of the rack, the axial flow fan is arranged in the part of the air guide channel extending out of the rack, and a filter screen is arranged at the air outlet.

Further, an electrical box is arranged on the machine frame and is arranged outside the forming space.

Compared with the prior art, the invention has the following advantages:

according to the invention, the hot bed part of the large-size printing platform is divided into a plurality of small-size hot bed units, so that the problem that the large-size hot bed is subjected to stress deformation when being heated, and flatness errors are caused can be effectively avoided;

meanwhile, the heat bed is leveled and locked independently by each heat bed unit, so that the leveling and fixing of the whole heat bed are realized, the constant level precision is ensured, multiple times of adjustment are not needed, the operation is simplified, and the printing efficiency is improved;

the plurality of heating bed units adopt an independent heating mode during heating, so that the temperature control precision of the printing platform in the printing process can be improved, and the stability and the printing precision are improved;

be equipped with hot-blast dual cycle space heating element in the shaping space, thereby take away the lower air of upper portion relative temperature in the shaping space, and heat into the hot-air, upwards blow off from print platform's bottom, can be favorable to the flow of hot-air in the shaping space on the one hand like this, on the other hand can utilize the steam that hot-blast dual cycle space heating element blown off to carry out the secondary heat preservation heating to print platform, guarantee that the temperature of each part of print platform is even, avoid hot-blast direct blowing to the model printing district simultaneously, utilize blocking of print platform to expand hot-blast to all around scattering, make hot-blast evenly be full of whole shaping space, effectively improve the shaping precision and the surface quality of goods.

Drawings

FIG. 1 is a schematic diagram of the overall structure of a large-size printing platform 3D printing device with constant space temperature;

FIG. 2 is a schematic diagram of the internal structure of a rack of a large-size printing platform 3D printing device with a constant space temperature;

FIG. 3 is a schematic structural diagram of a three-axis movement mechanism and a printing platform assembly of a large-size printing platform 3D printing device with constant space temperature;

FIG. 4 is a schematic isometric view of a printing platform assembly of a large-scale printing platform 3D printing apparatus with constant temperature in space;

FIG. 5 is an exploded view of the printing platform components of a large-scale printing platform 3D printing apparatus with constant temperature space;

FIG. 6 is a schematic diagram of a front view of a printing platform assembly of a large-size printing platform 3D printing device with constant temperature space;

FIG. 7 is an enlarged schematic view of portion A of FIG. 6;

FIG. 8 is a bottom view of a combination hotbed of a large-scale printing platform 3D printing device with constant temperature in space;

FIG. 9 is a schematic cross-sectional view taken along line B-B of FIG. 8;

FIG. 10 is a right side view of a large-scale printing platform 3D printing device with a constant temperature space;

FIG. 11 is a schematic cross-sectional view taken along the line A-A of FIG. 10

Description of reference numerals: 1. a frame; 2. x, Y a shaft motion assembly; 3. a Z-axis motion assembly; 4. a front door; 5. a heat dissipating component; 6. a printing platform assembly; 601. hot bed glass; 602. a combined hot bed; 603. a printing platform support; 604. a printing platform push-pull structure; 605. a hot bed fixing plate; 606. a hot bed heating mantle; 607. pressing and buckling the front of the hot bed glass; 608. heating a hot bed plate; 610. a groove; 611. a bump; 612. a hot bed glass rear buckle; 7. a hot air double circulation space heating assembly; 701. an air outlet; 702. an axial flow fan; 703. a heating device; 704. an air guide duct; 705. an air inlet; 8. an automatic cleaning assembly; 9. an illumination device; 10. a retractable thermal insulation member; 11. a printing platform horizontal adjustment assembly; 1101. adjusting the bolt; 1102. a locking nut; 1103. adjusting the nut; 1104. a spring mount; 1105. adjusting the spring; 12. a printing platform locking assembly; 1201. fixing the bolt; 1202. fixing a locking nut; 13. an electrical box; 14. a showerhead assembly.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

Examples

As shown in fig. 1 to 3, a large-size printing platform 3D printing device with a constant space temperature comprises a frame 1 of the device, heat-insulating layers are arranged on the periphery and the bottom of the frame 1, the heat-insulating layers can be formed by metal plates and heat-insulating cotton, a front door 4 is arranged on the front surface of the frame 1, a three-axis movement mechanism is arranged on the frame 1, X, Y-axis movement components 2 of the three-axis movement mechanism are arranged at the top of the frame 1, telescopic heat-insulating pieces 10 are further arranged on X, Y-axis movement components 2, a Z-axis movement component 3 is arranged on the outer side surface of each heat-insulating layer, the heat-insulating layers, a forming space is formed by the telescopic heat-insulating pieces 10 and cavities surrounded by the front door, a printing platform component 6, a spray head component 14 and a hot air double-circulation space heating component 7 are arranged in the forming space. The printing platform assembly 6 is specifically arranged in the middle of the bottom of the forming space, the hot air double-circulation space heating assemblies 7 are arranged on two sides of the forming space, the air inlet 705 of each hot air double-circulation space heating assembly is arranged at the top of the forming space, and the air outlet 701 is arranged right below the printing platform assembly 6. The interior of the forming space may also be provided with an automatic cleaning assembly 8 and a lighting device 9, which will not be described in more detail since the automatic cleaning assembly 8 and the lighting device 9 are not the main design parts of this patent. An electrical box 13 is arranged outside the molding space to accommodate electrical components of the device and the like, thereby avoiding reduction of working performance or shortening of service life caused by overhigh temperature inside the molding space.

As shown in fig. 4 and 5, the printing platform assembly 6 includes a heat bed assembly, a heat bed fixing plate 605, and a printing platform bracket 603 for connecting and fixing the heat bed fixing plate 605, wherein the printing platform bracket 603 is connected and fixed in the middle of the bottom of the forming space. The hot bed component comprises hot bed glass 601, a combined hot bed 602, a hot bed heating cover 606 and a hot bed heating plate 608 which are sequentially stacked from top to bottom, the combined hot bed 602 is formed by splicing a plurality of hot bed units, each hot bed unit is provided with at least two groups of printing platform horizontal adjusting components 11 and at least one group of printing platform locking components 12, the hot bed heating cover 606 covers the hot bed heating plate 608, and the hot bed heating plate 608 separately heats the hot bed units according to the positions and the number of the hot bed units. The hot bed assembly is provided with a hot bed glass front press button 607 and a hot bed glass rear button 612 on the sides to press the hot bed glass 601, the combined hot bed 602, the hot bed heating cover 606 and the hot bed heating plate 608 together. A printing platform push-pull structure 604 is connected between the hot bed fixing plate 605 and the printing platform bracket 603, so that the whole printing platform can be pushed and pulled towards the front door 4 in the molding space, and a user can open the front door 4 to take out a product.

In the combined heat bed 602, as shown in fig. 8 and 9, a heat bed sliding structure is arranged between two connected heat bed units, the heat bed sliding structure comprises a convex block 611 arranged on the side surface of the edge of one heat bed unit in a protruding mode, and a groove 610 matched with the convex block 611 in a shape in a concave mode and arranged on the side surface of the edge of the other heat bed unit in a concave mode, and a sliding gap is reserved between the connected heat bed units through the connection of the heat bed sliding structure. Specifically, the shape of the protrusion 611 is a semicircle, the shape of the groove 610 is also a semicircle matched with the protrusion 611, and a sliding fit gap is left between adjacent heat bed units, so that the flatness error of the large-size heat bed caused by material deformation and stress deformation during processing can be effectively reduced.

As shown in fig. 6 and 7, the printing platform horizontal adjustment assembly 11 includes an adjustment bolt 1101, a lock nut 1102, an adjustment nut 1103, a spring base 1104 and an adjustment spring 1105, the adjustment bolt 1101 penetrates through the spring base 1104, and an end portion of the adjustment bolt 1101 is connected with a bottom portion of the heat bed assembly, the spring base 1104 is disposed on a top surface of the heat bed fixing plate 605, two ends of the adjustment spring 1105 respectively abut against the spring base 1104 and a bottom surface of the heat bed heating plate 608, the adjustment nut 1103 is screwed with the adjustment bolt 1101 and abuts against a bottom surface of the heat bed fixing plate 605, and the lock nut 1102 is screwed with the adjustment bolt 1101 and abuts against a bottom portion of the adjustment nut 1103. When the printing platform horizontal adjusting assembly 11 is used for leveling, firstly, the locking nut 1102 is loosened, then the adjusting nut 1103 is rotated to enable the heating bed assembly mounted on the heating bed fixing plate 605 to adjust the height up and down under the action of the adjusting spring 1105, and after the adjustment is completed, the locking nut 1102 is screwed.

The printing platform locking assembly 12 comprises a fixing bolt 1201 and two fixing locking nuts 1202, the fixing bolt 1201 penetrates through the heat bed fixing plate 605 and the heat bed heating plate 608 in sequence, the end of the fixing bolt abuts against the bottom of the heat bed unit, and the two fixing locking nuts 1202 are respectively arranged on the top surface and the bottom surface of the heat bed fixing plate 605. When the printing platform locking assembly 12 is used for locking the position of the printing platform, firstly, two fixing locking nuts 1202 need to be loosened to enable the two fixing locking nuts 1202 to be far away from the heat bed fixing plate 605, then, the printing platform horizontal adjusting assembly 11 is used for leveling the levelness of the printing platform, after the leveling is finished, if the printing platform receives a certain weight, the printing platform still moves up and down at a small distance under the action of an adjusting spring 1105, at the moment, the end parts of the fixing bolts 1201 are abutted against the bottom of the heat bed unit, so that the whole heat bed assembly cannot move downwards in the working process, then, the two fixing locking nuts 1202 are screwed to fix the position of the fixing bolts 1201 at the moment, and the position fixing of the printing platform is completed.

As shown in fig. 10 and 11, the hot air dual-circulation space heating assembly 7 includes thermal circulation assemblies symmetrically disposed at two sides of the forming space, the thermal circulation assemblies include an air duct 704, a heating device 703 and an axial flow fan 702, an air inlet 705 of the air duct 704 is disposed at an upper portion of the forming space and faces a middle portion of the forming space, and an air outlet 701 of the air duct 704 is disposed at a lower portion of the forming space and faces a bottom portion of the printing platform assembly 6. The part of the air guide channel 704 extends out of the rack 1, the axial flow fan 702 is arranged in the part of the air guide channel 704 extending out of the rack 1, and a filter screen can be arranged at the air outlet 701. When the hot air dual-circulation space heating assembly 7 is in operation, firstly, air in the molding space is sucked into the air guide duct 704 through the air inlet 705 by the axial flow fan 702, and after the air enters the air guide duct 704, the air passes through the heating device 703, is heated at a high temperature set by a program, then flows to the air outlet 701 along a channel in the air guide duct 704, and is finally blown out. Because the air outlet 701 of the hot air double-circulation space heating assembly 7 is arranged right below the printing platform, hot air heated by the heating device 703 is driven by the axial flow fan 702, the temperature is stable and uniform, after the air outlet 701 is blown out, the bottom surface of the printing platform is impacted, the air is dispersed all around, and meanwhile, the hot air is uniformly filled in the area of a printing model of the printer by utilizing the upward movement characteristic of the hot air, so that the temperature of a printing plane can reach the temperature set by a program and keep constant. Finally, after the molding space is heated by the hot air, the temperature of the molding space is reduced, and at the moment, the hot air with the reduced temperature is sucked into the air guide duct 704 again from the air inlet 705 by the axial flow fan 702, so that a heating cycle is formed.

The invention divides the hot bed part of the large-size printing platform into a plurality of small-size hot bed units, can effectively avoid the self stress deformation of the large-size hot bed during heating to bring flatness error, simultaneously levels and locks each hot bed unit independently to realize the leveling of the whole hot bed, a hot air double-circulation space heating component 7 is arranged in the forming space, thereby pumping air with lower relative temperature at the upper part in the forming space, heating the air into hot air, and blowing the hot air upwards from the bottom of the printing platform, thus being beneficial to the flow of the hot air in the forming space on one hand, and utilizing the hot air blown out by the hot air double-circulation space heating component to carry out secondary heat preservation heating on the printing platform on the other hand, ensuring the uniform temperature of each part of the printing platform, and avoiding the hot air from directly blowing to a model printing area, the hot air is spread to the periphery by the blocking of the printing platform, so that the whole forming space is uniformly filled with the hot air, and the forming precision and the surface quality of the product are effectively improved.

The above embodiments are only for illustrating the technical concept and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement the present invention accordingly, and not to limit the protection scope of the present invention accordingly. All equivalent changes or modifications made in accordance with the spirit of the present disclosure are intended to be covered by the scope of the present disclosure.

Claims

1. The utility model provides a homothermal jumbo size print platform 3D printing device in space which characterized in that: the device comprises a device frame (1), wherein a three-axis movement mechanism is arranged on the frame (1), a heat insulation layer is arranged on the inner side of the frame (1), a front door (4) is arranged on the front side of the frame, a forming space is formed by the heat insulation layer and a cavity enclosed by the inner part of the front door (4), a printing platform assembly (6), a spray head assembly (14) and a hot air double-circulation space heating assembly (7) are arranged in the forming space, the spray head assembly (14) is arranged in the forming space through the three-axis movement mechanism, the printing platform assembly (6) is arranged at the bottom of the forming space, an air inlet (705) of the hot air double-circulation space heating assembly (7) is arranged at the top of the forming space, and an air outlet (701) of the hot air double-circulation space heating assembly (7) is arranged;

print platform subassembly (6) are including hot bed subassembly, hot bed fixed plate (605) and be used for connecting print platform support (603) of fixed hot bed fixed plate (605), the hot bed subassembly is including hot bed glass (601), combination hot bed (602) and hot bed hot plate (608) that stack in proper order from top to bottom, print platform support (603) are connected and are fixed in the bottom in shaping space, combination hot bed (602) are including a plurality of hot bed unit concatenation constitution, all are equipped with at least a set of print platform horizontal adjustment subassembly (11) and at least two sets of print platform locking Assembly (12) on every hot bed unit.

2. The spatially-thermostatted, large-format print platform 3D printing apparatus of claim 1, wherein: the printing platform horizontal adjusting assembly (11) comprises an adjusting bolt (1101), a locking nut (1102), an adjusting nut (1103), a spring base (1104) and an adjusting spring (1105), wherein the adjusting bolt (1101) penetrates through the spring base (1104), the end part of the adjusting bolt is connected with the bottom of the hot bed assembly, the spring base (1104) is arranged on the top surface of the hot bed fixing plate (605), the two ends of the adjusting spring (1105) are respectively abutted against the spring base (1104) and the bottom surface of the hot bed heating plate (608), the adjusting nut (1103) is in threaded connection with the adjusting bolt (1101) and abutted against the bottom surface of the hot bed fixing plate (605), and the locking nut (1102) is in threaded connection with the adjusting bolt (1101) and abutted against the bottom of the adjusting nut (1103).

3. The spatially-thermostatted, large-format print platform 3D printing apparatus of claim 1, wherein: the printing platform locking assembly (12) comprises a fixing bolt (1201) and two fixing locking nuts (1202), the fixing bolt (1201) sequentially penetrates through a hot bed fixing plate (605) and a hot bed heating plate (608), the end portion of the fixing bolt is abutted to the bottom of the hot bed unit, and the two fixing locking nuts (1202) are respectively arranged on the top surface and the bottom surface of the hot bed fixing plate (605).

4. The spatially-thermostatted, large-format print platform 3D printing apparatus of claim 1, wherein: the hot bed heating plate (608) separately heats the hot bed units according to the position and the number of the hot bed units.

5. The spatially-thermostatted, large-format print platform 3D printing apparatus of claim 1, wherein: a heat bed sliding fit structure is arranged between two connected heat bed units and comprises a convex block (611) which is convexly arranged on the side surface of the edge of one heat bed unit and a concave groove (610) which is concavely arranged on the side surface of the edge of the other heat bed unit and is matched with the convex block (611) in shape, and a sliding fit gap is reserved between the connected heat bed units through the connection of the heat bed sliding fit structure.

6. The spatially-thermostatted, large-format print platform 3D printing apparatus of claim 6, wherein: the shape of the projection (611) is semicircular.

7. The spatially-thermostatted, large-format print platform 3D printing apparatus of claim 1, wherein: the hot air double-circulation space heating assembly (7) comprises thermal circulation assemblies symmetrically arranged on two sides of a forming space, each thermal circulation assembly comprises an air guide channel (704), a heating device (703) and an axial flow fan (702), an air inlet (705) of each air guide channel (704) is formed in the upper portion of the forming space and is opposite to the middle of the forming space, an air outlet (701) of each air guide channel (704) is formed in the lower portion of the forming space and is opposite to the bottom of the printing platform assembly (6), air enters the air guide channels (704) from the air inlets (705), sequentially passes through the heating devices (703) and the axial flow fans (702), and finally is blown out from the air outlets (701).

8. The spatially-thermostatted, large-format print platform 3D printing apparatus of claim 8, wherein: the part of the air guide duct (704) extends out of the rack (1), the axial flow fan (702) is arranged in the part of the air guide duct (704) extending out of the rack (1), and a filter screen is arranged at the air outlet (701).

9. The spatially-thermostatted, large-format print platform 3D printing apparatus of claim 1, wherein: an electric box (13) is further arranged on the rack (1), and the electric box (13) is arranged on the outer side of the forming space.