Desktop-level extrusion type 3D biological printer with closed refrigeration cavity

Abstract

The invention discloses a desktop-level extrusion type 3D biological printer with a closed refrigeration cavity, relates to the technical field of biological 3D printing, and solves the problem existing in the refrigeration aspect in the biological 3D printing process, the printer is internally provided with a refrigeration cavity of a closed structure, during printing, most of refrigerated air is reserved in the cavity, and the refrigeration cavity is sealed. The refrigeration sheets are installed on the upper face, the lower face, the left face, the right face, the front face and the rear face of the closed printing cavity, and the problem that the temperature rises along with the increase of the printing height due to the fact that the refrigeration sheets only exist at the bottom is solved through refrigeration in all directions. A series of plate-shaped structures are arranged outside the printer, the internal space of the printer is isolated from the external environment, the closed freezing cavity is always in a stable temperature environment in an air cooling mode, the problem that the printer is greatly influenced by the room temperature due to an open structure is solved, and the temperature of the closed freezing cavity is more stable.

Description

Technical Field

[0001] The invention relates to a desktop extrusion-type 3D bioprinter with a closed refrigeration chamber, and belongs to the technical field of 3D printing. Background Art

[0002] 3D bioprinting is a new technology that combines 3D printing with the medical field. It is defined as the use of a computer-assisted transfer process to deposit biomaterials and living cells layer by layer, which can create tissue structures with heterogeneous components and complex structures, such as cartilage, skin, and heart valves. Among them, extrusion 3D bioprinting has great advantages due to its relatively low cost and system complexity, such as accurate, continuous, and rapid deposition of bio-inks. The hydrogel structure obtained by extrusion printing of bio-inks often needs to be shaped by physical or chemical cross-linking. Compared with chemical cross-linking, the use of frozen physical cross-linking is favored because no other foreign substances are introduced during the cross-linking process. The basis of frozen extrusion 3D bioprinting is the need to design a frozen printing chamber that meets the requirements of biomanufacturing, which is also one of the key issues that need to be addressed in the field of bioprinting today.

[0003] Currently, the common desktop-level frozen extrusion 3D bioprinter still has some shortcomings. The patent application announcement number is CN202223320169.4, and the invention name is a biological 3D printer with a refrigerated printing platform. It provides a biological 3D printer with a refrigeration platform. However, in this scheme, due to the small size of the printer, its frozen printing platform is open, and the air cooled by the platform will quickly dissipate into the external space, reducing the refrigeration efficiency of the printer, and only the refrigeration sheet is installed at the bottom of the printing platform. Therefore, the closer to the printing platform, the lower the temperature. As the printing nozzle is lifted, the temperature will gradually increase. Often after printing a few layers, the temperature does not meet the requirements of frozen cross-linking, resulting in the inability to form the ink. In some printers, this defect is compensated by adding a refrigeration unit, but this The power consumption of the printer is increased, which is not in line with the current development concept of energy conservation and emission reduction. In addition, this open printer will be greatly affected by the temperature of the environment. The room temperature will greatly affect the printer's refrigeration efficiency, refrigeration time and minimum refrigeration temperature, which increases the instability of the printer during the printing process. In addition, the biological ink printed by the bioprinter is mixed with biological cells, so the printing environment is required to be non-toxic and sterile. The current desktop-level frozen extrusion 3D bioprinter often uses a single ultraviolet light sterilization method, but there is still a risk of bacterial residues in the past where ultraviolet light cannot reach, and the more comprehensive alcohol disinfection method has limited effect in an open printing space, and the residual alcohol may also reduce cell activity and affect subsequent cell printing experiments.

[0004] In summary, the existing desktop-level frozen extrusion 3D bioprinters have the following defects: 1. The open printing platform causes cold air to be emitted, reducing the cooling efficiency and printing efficiency; 2. Usually only the lower printing platform is installed with the right cooling plate, which causes the temperature to decrease with the increase of height: 3. Adding a refrigeration unit speeds up the cooling speed while increasing power consumption: 4. The open structure causes the printer to be greatly affected by room temperature, increasing its instability; 5. The single ultraviolet light sterilization and disinfection method has the risk of bacterial residue, and should be combined with alcohol disinfection to make it more comprehensive. Summary of the invention

[0005] In view of the above-mentioned problems of defects in desktop extrusion 3D bioprinters, an object of the present invention is to provide a desktop extrusion 3D bioprinter with a closed refrigeration chamber.

[0006] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a desktop extrusion 3D bioprinter with a closed refrigeration chamber, comprising a main frame, a Z-axis moving mechanism, a Y-axis moving mechanism, an X-axis moving mechanism, a closed refrigeration mechanism, an air cooling mechanism, an ultraviolet sterilization device, a temperature detection device and a printing nozzle; the Z-axis moving mechanism 2 is movably connected to the main frame 1 along the vertical direction, the Y-axis moving mechanism 3 is movably connected to the main frame 1 along the front-back direction, and the X-axis moving mechanism 4 is movably connected to the main frame 1 along the left-right direction; the printing nozzle 9 is installed on the X-axis moving mechanism 4, and a closed refrigeration mechanism 5 is arranged around the printing nozzle 9, the air cooling mechanism 6 is arranged below the closed refrigeration mechanism 5 and on one side of the Z-axis moving mechanism 2, the ultraviolet sterilization device 7 is arranged at the bottom of the main frame 1, and the temperature detection device 8 is arranged around the closed refrigeration mechanism 5.

[0007] Furthermore, the above-mentioned desktop extrusion 3D bioprinter with a closed refrigeration chamber, wherein the main frame includes: a mounting frame, a left protective plate, a right protective plate, an upper protective plate, a lower protective plate, a rear protective plate and a front frame plate, the mounting frame is an integral structure, and has threaded holes for mounting at specific positions thereof, and a left Z-axis frame structure and a right Z-axis frame structure are provided on the left and right sides for mounting a Z-axis moving mechanism, and the left Z-axis frame structure and the right Z-axis frame structure are connected by two horizontal bars, the left protective plate is mounted on the left side of the mounting frame, and the right protective plate is mounted on On the right side of the mounting frame, the upper protective plate is mounted on the top of the mounting frame, the lower protective plate is mounted on the bottom of the mounting frame, the rear protective plate is mounted on the back of the mounting frame, and the front frame plate is mounted on the front of the mounting frame; the main frame also includes: a front protective plate, an upper hinge and a lower hinge, the front frame plate has a through hole for hinge installation, the upper hinge and the lower hinge are installed on the mounting frame through the through hole, the front protective plate is connected with the upper hinge and the lower hinge through a hole-like structure, and is installed in front of the mounting frame, forming a closed structure together with the protective plates in other directions.

[0008] Furthermore, in the above-mentioned desktop extrusion 3D bio-printer with a closed refrigeration chamber, the Z-axis moving mechanism includes: an upper fixing member on the left side of the Z-axis, a lower fixing member on the left side of the Z-axis, a lead screw on the left side of the Z-axis, a stepping motor on the left side of the Z-axis and a climbing member on the left side of the Z-axis. The upper fixing member on the left side of the Z-axis and the lower fixing member on the left side of the Z-axis are respectively assembled on the upper and lower sides of the left side Z-axis frame structure of the mounting frame through the through holes thereon, the lead screw on the left side of the Z-axis is fixed at the central circular holes of the upper fixing member on the left side of the Z-axis and the lower fixing member on the left side of the Z-axis, and passes through the stepping motor on the left side of the Z-axis, and the climbing member on the left side of the Z-axis is mounted on the stepping motor on the left side of the Z-axis. It can move up and down driven by the left stepper motor; the Z-axis moving mechanism also includes: an upper fixing part on the right side of the Z-axis, a lower fixing part on the right side of the Z-axis, a right lead screw on the Z-axis, a right stepper motor on the Z-axis and a right climbing part on the Z-axis. The upper fixing part on the right side of the Z-axis and the lower fixing part on the right side of the Z-axis are respectively assembled on the upper and lower sides of the right side Z-axis frame structure of the mounting frame through the through holes thereon, the right lead screw on the Z-axis is fixed at the central circular holes of the upper fixing part on the right side of the Z-axis and the lower fixing part on the right side of the Z-axis, and passes through the right stepper motor on the Z-axis. The right climbing part on the Z-axis is installed on the right stepper motor on the Z-axis and can move up and down driven by the left stepper motor on the Z-axis.

[0009] Furthermore, in the above-mentioned desktop extrusion 3D bioprinter with a closed refrigeration chamber, the Z-axis moving mechanism also includes a first lifting rod, a second lifting rod and a printing plate fixing frame, the two ends of the first lifting rod and the second lifting rod are respectively fixed in the groove structures on both sides of the left climbing member and the right climbing member of the Z-axis, and the Z-axis can be moved up and down under the drive of the left climbing member and the right climbing member of the Z-axis, and the printing plate fixing frame is assembled in the middle part of the first lifting rod and the second lifting rod, and moves up and down with the first lifting rod and the second lifting rod.

[0010] Furthermore, the above-mentioned desktop extrusion 3D bioprinter with a closed refrigeration chamber, wherein the Y-axis moving mechanism includes: a Y-axis left side moving component, the Y-axis left side moving component includes: a Y-axis left side optical axis front fixing part, a Y-axis left side optical axis rear fixing part, a Y-axis left side lead screw front fixing part, a Y-axis left side lead screw rear fixing part, a Y-axis left side optical axis, a Y-axis left side lead screw, a Y-axis left side linear bearing, a Y-axis left side stepper motor and a Y-axis left side connecting part, the Y-axis left side optical axis front fixing part and the Y-axis left side lead screw front fixing part are assembled on the front side of the mounting frame through the through holes thereon, and the Y-axis left side optical axis rear fixing part The fixing part and the rear fixing part of the left side lead screw of the Y-axis are assembled on the rear side of the mounting frame, the left side optical axis of the Y-axis passes through the left side linear bearing of the Y-axis, and is fixed at the middle circular hole of the front fixing part of the left side optical axis of the Y-axis and the rear fixing part of the left side optical axis of the Y-axis, the left side lead screw of the Y-axis passes through the left side stepping motor of the Y-axis, and is fixed in the middle circular hole of the front fixing part of the left side lead screw of the Y-axis and the rear fixing part of the left side lead screw of the Y-axis, the upper part of the left side connecting part of the Y-axis is connected to the left side linear bearing of the Y-axis, and the lower part is connected to the left side stepping motor of the Y-axis, and driven by the left side stepping motor of the Y-axis, the left side connecting part of the Y-axis can realize forward and backward movement in the direction of the Y-axis.

[0011] Furthermore, the above-mentioned desktop extrusion 3D bioprinter with a closed refrigeration chamber, wherein the Y-axis moving mechanism also includes a Y-axis right side moving component, and the Y-axis right side moving component includes: a Y-axis right side optical axis front fixing part, a Y-axis right side optical axis rear fixing part, a Y-axis right side lead screw front fixing part, a Y-axis right side lead screw rear fixing part, a Y-axis right side optical axis, a Y-axis right side lead screw, a Y-axis right side linear bearing, a Y-axis right side stepper motor and a Y-axis right side connecting part, the Y-axis right side optical axis front fixing part and the Y-axis right side lead screw front fixing part are assembled on the front side of the mounting frame through the through holes thereon, and the Y-axis right side optical axis rear fixing part The fixing part and the rear fixing part of the right side lead screw of the Y-axis are assembled on the rear side of the mounting frame, the right side optical axis of the Y-axis passes through the right side linear bearing of the Y-axis, and is fixed at the middle circular hole of the front fixing part of the right side optical axis of the Y-axis and the rear fixing part of the right side optical axis of the Y-axis, the right side lead screw of the Y-axis passes through the right side stepper motor of the Y-axis, and is fixed in the middle circular hole of the front fixing part of the right side lead screw of the Y-axis and the rear fixing part of the right side lead screw of the Y-axis, the upper part of the right side connecting part of the Y-axis is connected to the right side linear bearing of the Y-axis, and the lower part is connected to the right side stepper motor of the Y-axis, and driven by the right side stepper motor of the Y-axis, the right side connecting part of the Y-axis can realize forward and backward movement in the direction of the Y-axis.

[0012] Furthermore, in the above-mentioned desktop extrusion 3D bioprinter with a closed refrigeration chamber, the X-axis moving mechanism includes an X-axis left optical axis fixing member, an X-axis right optical axis fixing member, an X-axis left lead screw fixing member, an X-axis right lead screw fixing member, an X-axis optical axis, an X-axis lead screw, an X-axis linear bearing, an X-axis stepper motor and an X-axis connecting member, the X-axis left optical axis fixing member and the X-axis left lead screw fixing member are assembled on the Y-axis left connecting member through the through holes thereon, and the X-axis right optical axis fixing member and the X-axis right lead screw fixing member are assembled on the Y-axis left connecting member through the through holes thereon The fixed part is assembled on the right connecting part of the Y-axis through the through hole thereon, the X-axis optical axis passes through the X-axis linear bearing and is fixed at the middle circular holes of the left optical axis fixing part of the X-axis and the right optical axis fixing part of the X-axis, the X-axis lead screw passes through the X-axis stepper motor and is fixed at the center circular holes of the left lead screw fixing part of the X-axis and the right lead screw fixing part of the X-axis, the upper part of the X-axis connecting part is connected to the X-axis linear bearing, and an X-axis stepper motor is installed inside. Driven by the X-axis stepper motor, the X-axis connecting part can realize left and right movement in the X-axis direction.

[0013] Further, the above-mentioned desktop extrusion 3D bioprinter with a closed refrigeration chamber, wherein the closed refrigeration mechanism includes: an upper refrigeration unit, the upper refrigeration unit includes: an upper refrigeration plate, an upper refrigeration sheet, an upper water-cooling head, an upper refrigeration fixing plate, an upper thermal insulation plate, an upper water inlet pipe and an upper water outlet pipe, the upper refrigeration plate is installed below the X-axis connecting piece, the lower side of the upper refrigeration sheet is attached to the middle part of the upper refrigeration plate, and the upper side is attached to the upper water-cooling head, a screw is welded in the middle of the upper refrigeration plate, the upper refrigeration fixing plate is assembled on the screw through the through hole thereon, and the upper refrigeration sheet and the upper water-cooling head are fixed on the upper refrigeration plate, the upper thermal insulation plate is assembled above the upper refrigeration plate, the water-cooling head has two holes for water inlet and water outlet, the upper water inlet pipe and the upper water outlet pipe are connected to the two holes of the upper water-cooling head, the upper water inlet pipe is on the right side, and the upper water outlet pipe is on the left side.

[0014] Further, the above-mentioned desktop extrusion 3D bioprinter with a closed refrigeration chamber, wherein the closed refrigeration mechanism also includes: a central refrigeration unit, the central refrigeration unit includes: a central refrigeration plate, a front refrigeration sheet, a front water-cooling head, a front refrigeration fixing plate, a front insulation plate, a rear refrigeration sheet, a rear water-cooling head, a rear refrigeration fixing plate, a rear insulation plate, a left refrigeration sheet, a left water-cooling head, a left refrigeration fixing plate, a left insulation plate, a right refrigeration sheet, a right water-cooling head, a right refrigeration fixing plate and a right insulation plate, the central refrigeration plate is assembled in the installation The frame is installed in the middle of the two horizontal bars connecting the left Z-axis frame structure and the right Z-axis frame structure. The middle refrigeration plate is a square structure. There are two welded screws on the outside of the four directions of the front, rear, left and right sides. One side of the front refrigeration plate is attached to the front side of the middle refrigeration plate, and the other side is attached to the front water-cooling head. The front refrigeration fixing plate is installed on the screws on the front side of the middle refrigeration plate through the through holes thereon, and fixes the front refrigeration plate and the front water-cooling head. The front insulation plate is attached to the front side of the middle refrigeration plate, and one side of the rear refrigeration plate is attached to the middle The rear side of the refrigeration plate is attached, and the other side is attached to the rear water-cooling head. The rear refrigeration fixing plate is installed on the screws on the rear side of the middle refrigeration plate through the through holes thereon, and fixes the rear refrigeration fin and the rear water-cooling head. The rear insulation plate is attached to the rear side of the middle refrigeration plate, one side of the left refrigeration fin is attached to the left side of the middle refrigeration plate, and the other side is attached to the left water-cooling head. The left refrigeration fixing plate is installed on the screws on the left side of the middle refrigeration plate through the through holes thereon, and fixes the left refrigeration fin and the left water-cooling head. The left insulation plate is attached to the left side of the middle refrigeration plate. One side of the right refrigeration plate is attached to the rear side of the middle refrigeration plate, and the other side is attached to the right water-cooling head. The right refrigeration fixing plate is installed on the screws on the right side of the middle refrigeration plate through the through holes thereon, and fixes the right refrigeration plate and the right water-cooling head. The right insulation plate is attached to the right side of the middle refrigeration plate; the middle refrigeration unit also includes: a middle water inlet pipe and a middle water outlet pipe, both of which are annular tubular structures, the middle water inlet pipe is connected to the hole on the upper side of each middle water-cooling head, and the middle water outlet pipe is connected to the hole on the lower side of each middle water-cooling head.

[0015] Furthermore, the above-mentioned desktop extrusion 3D bioprinter with a closed refrigeration chamber, wherein the closed refrigeration mechanism also includes: a lower refrigeration unit, the lower refrigeration unit includes: a printing plate, a lower refrigeration sheet, a lower water-cooling head, a lower refrigeration fixing plate, a lower insulation plate, a lower water inlet pipe and a lower water outlet pipe, the printing plate is installed above the printing plate fixing frame, and two screws are welded below the printing plate, one side of the lower refrigeration sheet is attached to the bottom of the printing plate, and the other side is attached to the lower water-cooling head, the lower refrigeration fixing plate is installed on the screws below the printing plate through the through holes thereon, and fixes the lower refrigeration sheet and the lower water-cooling head, the lower insulation plate is attached to the bottom of the printing plate, the lower water inlet pipe and the lower water outlet pipe are connected to the two holes of the lower water-cooling head, the lower water inlet pipe is on the right side, and the lower water outlet pipe is on the left side.

[0016] Furthermore, in the above-mentioned desktop extrusion 3D bioprinter with a closed refrigeration chamber, the closed air cooling mechanism includes: a left air cooler and a right air cooler, the left air cooler is installed on the left side of the rear protective plate through the through hole thereon, and the right air cooler is installed on the right side of the rear protective plate through the through hole thereon.

[0017] Furthermore, in the above-mentioned desktop extrusion 3D bioprinter with a closed refrigeration chamber, the ultraviolet sterilization device includes: an upper left ultraviolet lamp, an upper right ultraviolet lamp, a lower left ultraviolet lamp and a lower right ultraviolet lamp, the upper left ultraviolet lamp is mounted on the upper left beam of the mounting frame, the upper right ultraviolet lamp is mounted on the upper right beam of the mounting frame, the lower left ultraviolet lamp is mounted on the lower left beam of the mounting frame, and the lower right ultraviolet lamp is mounted on the lower right beam of the mounting frame.

[0018] Furthermore, in the above-mentioned desktop extrusion 3D bioprinter with a closed refrigeration chamber, the temperature detection device includes: a cavity temperature sensor, a cavity sensor fixture, an air-cooled temperature sensor and an air-cooled sensor fixture, the cavity temperature sensor is installed inside the cavity sensor fixture, the cavity sensor fixture is fixed on the screws of the upper refrigeration plate, the air-cooled temperature sensor is installed inside the air-cooled sensor fixture, and the air-cooled sensor fixture is installed on the cross bar of the mounting frame.

[0019] The above-mentioned desktop extrusion 3D bioprinter with a closed refrigeration chamber, wherein the printing nozzle 9 can be an extrusion nozzle device disclosed in the utility model patent CN202220671744.6.

[0020] Due to the adoption of the above technology, the present invention has the following positive effects compared with the prior art:

[0021] 1. The present invention adopts a closed refrigeration chamber structure. Compared with an open refrigeration platform, this structure has a better heat preservation effect. The prepared cold air will not be easily lost into the air, thereby improving the refrigeration efficiency of the printer, shortening the initial refrigeration time, and increasing the printing efficiency of the printer.

[0022] 2. In the present invention, cooling sheets are installed on the six surfaces of the closed printing chamber, including top, bottom, left, right, front and back. Refrigeration in all directions solves the problem of temperature rising with increasing printing height due to the existence of the cooling sheet only at the bottom. The upper cooling sheet can keep the temperature at the printing nozzle at a relatively low level, and the printing structure will not have the problem of being unable to freeze and cross-link due to the increase in the number of layers, resulting in the temperature not being low enough.

[0023] 3. The printer of the present invention adopts six refrigeration blocks. When the temperature drops to the temperature required for freezing and cross-linking, the refrigeration blocks are automatically closed. The closed printing chamber reduces the time required for cooling, reduces the power consumption of the printer, and is energy-saving and environmentally friendly.

[0024] Fourth, the air cooling structure composed of two fans in the present invention can cool down the inside of the printer by air cooling when the printer is printing, so that the closed freezer chamber is always in a stable temperature environment, solving the problem that the printer is greatly affected by the room temperature due to the open structure, and making the temperature of the closed freezer chamber more stable.

[0025] 5. The ultraviolet sterilization device composed of four ultraviolet rays in the present invention allows the printer to be sterilized by ultraviolet rays. At the same time, the printer can also use alcohol sterilization. During this process, the fan will quickly vaporize the alcohol and it will not remain on the printing plate to affect cell activity. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of the present invention.

[0027] Figure 2 It is one of the main frame structure schematic diagrams of the present invention.

[0028] Figure 3 This is the second schematic diagram of the main frame structure of the present invention.

[0029] Figure 4 It is a schematic diagram of the structure of the Z-axis moving mechanism of the present invention.

[0030] Figure 5 It is a schematic diagram of the structure of the Y-axis moving mechanism of the present invention.

[0031] Figure 6 It is a schematic diagram of the X-axis moving mechanism structure of the present invention.

[0032] Figure 7It is one of the structural schematic diagrams of the closed refrigeration mechanism of the present invention.

[0033] Figure 8 This is the second structural schematic diagram of the closed refrigeration mechanism of the present invention.

[0034] Fig. 9 This is the third structural schematic diagram of the closed refrigeration mechanism of the present invention.

[0035] Fig.10 It is a schematic diagram of the structure of the air cooling mechanism of the present invention.

[0036] Fig.11 It is a schematic diagram of the structure of the ultraviolet sterilization device of the present invention.

[0037] Fig.12 It is a schematic diagram of the structure of the temperature detection device of the present invention.

[0038] Fig.13 It is a schematic diagram of the installation frame structure of the present invention.

[0039] Fig.14 It is the front view and side view of the X-axis connecting member of the present invention.

[0040] Fig.15 1 and 2 are a top view and a side view of the upper refrigeration plate of the present invention.

[0041] Fig.16 1 and 2 are a top view and a side view of the middle refrigeration plate of the present invention.

[0042] In the attached drawings: 1, main frame; 11, mounting frame; 12, left side guard plate; 13, right side guard plate; 14, upper guard plate; 15, lower guard plate; 16, rear guard plate; 17, front frame plate; 18, front guard plate; 19, upper hinge; 110, lower hinge;

[0043] 2. Z-axis moving mechanism; 21. Z-axis left upper fixing member; 22. Z-axis left lower fixing member; 23. Z-axis left lead screw; 24. Z-axis left stepping motor; 25. Z-axis left climbing member; 26. Z-axis right upper fixing member; 27. Z-axis right lower fixing member; 28. Z-axis right lead screw; 29. ​​Z-axis right stepping motor; 210. Z-axis right climbing member; 211. First lifting rod; 212. Second lifting rod; 213. Print plate fixing frame;

[0044] 3. Y-axis moving mechanism; 31. Y-axis left moving assembly; 311. Y-axis left optical axis front fixing piece; 312. Y-axis left optical axis rear fixing piece; 313. Y-axis left lead screw front fixing piece; 314. Y-axis left lead screw rear fixing piece; 315. Y-axis left optical axis; 316. Y-axis left lead screw; 317. Y-axis left linear bearing; 318. Y-axis left stepping motor; 319. Y-axis left connecting piece;

[0045] 32. Right side moving assembly of Y axis; 321. Front fixing part of right side optical axis of Y axis; 322. Rear fixing part of right side optical axis of Y axis; 323. Front fixing part of right side lead screw of Y axis; 324. Rear fixing part of right side lead screw of Y axis; 325. Right side optical axis of Y axis; 326. Right side lead screw of Y axis; 327. Right side linear bearing of Y axis; 328. Right side stepping motor of Y axis; 329. Right side connecting part of Y axis;

[0046] 4. X-axis moving mechanism; 41. X-axis left optical axis fixing part; 42. X-axis right optical axis fixing part; 43. X-axis left lead screw fixing part; 44. X-axis right lead screw fixing part; 45. X-axis optical axis; 46. X-axis lead screw; 47. X-axis linear bearing; 48. X-axis stepping motor; 49. X-axis connecting part;

[0047] 5. Closed refrigeration mechanism; 51. Upper refrigeration unit; 511. Upper refrigeration plate; 512. Upper refrigeration sheet; 513. Upper water cooling head; 514. Upper refrigeration fixing plate; 515. Upper insulation plate; 516. Upper water inlet pipe; 517. Upper water outlet pipe;

[0048] 52, middle refrigeration unit; 521, middle refrigeration plate; 522, front refrigeration fin; 523, front water-cooling head; 524, front refrigeration fixing plate; 525, front insulation plate; 526, rear refrigeration fin; 527, rear water-cooling head; 528, rear refrigeration fixing plate; 529, rear insulation plate; 5210 left refrigeration fin; 5211, left water-cooling head; 5212, left refrigeration fixing plate; 5213, left insulation plate; 5214, right refrigeration fin; 5215, right water-cooling head; 5216, right refrigeration fixing plate; 5217 right insulation plate; 5218, middle water inlet pipe; 5219, middle water outlet pipe;

[0049] 53, lower refrigeration unit; 531, printing board; 532, lower refrigeration plate; 533, lower water cooling head; 534, lower refrigeration fixing plate; 535, lower insulation board; 536, lower water inlet pipe; 537 lower water outlet pipe;

[0050] 6. Air cooling mechanism; 61. Left air cooling machine; 62. Right air cooling machine; 7. Ultraviolet sterilization device; 71. Upper left ultraviolet lamp; 72. Upper right ultraviolet lamp; 73. Lower left ultraviolet lamp; 74. Lower right ultraviolet lamp; 8. Temperature detection device; 81. Cavity temperature sensor; 82. Cavity sensor fixing part; 83. Air cooling temperature sensor; 84. Air cooling sensor fixing part; 9. Print nozzle. DETAILED DESCRIPTION

[0051] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0052] Please refer to Figures 1 to 16 As shown, a desktop extrusion 3D bioprinter with a closed refrigeration chamber is shown, which includes a main frame 1, a Z-axis moving mechanism 2, a Y-axis moving mechanism 3, an X-axis moving mechanism 4, a closed refrigeration mechanism 5, an air cooling mechanism 6, an ultraviolet sterilization device 7, a temperature detection device 8 and a print head 9; the Z-axis moving mechanism 2 is movably connected to the main frame 1 along the vertical direction, the Y-axis moving mechanism 3 is movably connected to the main frame 1 along the front-back direction, and the X-axis moving mechanism 4 is movably connected to the main frame 1 along the left-right direction; the print head 9 is installed on the X-axis moving mechanism 4, and a closed refrigeration mechanism 5 is arranged around the print head 9, the air cooling mechanism 6 is arranged below the closed refrigeration mechanism 5 and on one side of the Z-axis moving mechanism 2, the ultraviolet sterilization device 7 is arranged at the bottom of the main frame 1, and the temperature detection device 8 is arranged around the closed refrigeration mechanism 5.

[0053] Further, in a preferred embodiment: the main frame 1 includes a mounting frame 11, a left protective plate 12, a right protective plate 13, an upper protective plate 14, a lower protective plate 15, a rear protective plate 16 and a front frame plate 17, the mounting frame 11 is an integral structure, and a threaded hole for installation is provided at a specific position thereof, and a left Z-axis frame structure and a right Z-axis frame structure are provided on the left and right sides for installing the Z-axis moving mechanism 2, and the left Z-axis frame structure and the right Z-axis frame structure are connected by two horizontal bars, the left protective plate 12 is assembled on the left side of the mounting frame 11, the right protective plate 13 is assembled on the right side of the mounting frame 11, and the upper protective plate 1 4 is mounted on the top of the mounting frame 11, the lower protective plate 15 is mounted on the bottom of the mounting frame 11, the rear protective plate 16 is mounted on the back of the mounting frame 11, and the front frame plate 17 is mounted on the front of the mounting frame 11; the main frame 1 also includes: a front protective plate 18, an upper hinge 19 and a lower hinge 110, the front frame plate 17 has a through hole for hinge installation, the upper hinge 19 and the lower hinge 110 are installed on the mounting frame 11 through the through hole, the front protective plate 18 is connected with the upper hinge 19 and the lower hinge 110 through the hole structure, and is installed in front of the mounting frame 11, and together with the protective plates in other directions, it forms a closed structure.

[0054] Further, in a preferred embodiment: the Z-axis moving mechanism 2 includes: an upper fixing member 21 on the left side of the Z-axis, a lower fixing member 22 on the left side of the Z-axis, a lead screw 23 on the left side of the Z-axis, a stepper motor 24 on the left side of the Z-axis and a climbing member 25 on the left side of the Z-axis. The upper fixing member 21 on the left side of the Z-axis and the lower fixing member 22 on the left side of the Z-axis are respectively assembled on the upper and lower sides of the left side Z-axis frame structure of the mounting frame 11 through the through holes thereon. The lead screw 23 on the left side of the Z-axis is fixed at the central circular holes of the upper fixing member 21 on the left side of the Z-axis and the lower fixing member 22 on the left side of the Z-axis, and passes through the stepper motor 24 on the left side of the Z-axis. The climbing member 25 on the left side of the Z-axis is installed on the stepper motor 24 on the left side of the Z-axis. It can move up and down; the Z-axis moving mechanism 2 also includes: an upper fixing member 26 on the right side of the Z-axis, a lower fixing member 27 on the right side of the Z-axis, a lead screw 28 on the right side of the Z-axis, a stepper motor 29 on the right side of the Z-axis and a climbing member 210 on the right side of the Z-axis. The upper fixing member 26 on the right side of the Z-axis and the lower fixing member 27 on the right side of the Z-axis are respectively assembled on the upper and lower sides of the right side Z-axis frame structure of the mounting frame 11 through the through holes thereon, the lead screw 28 on the right side of the Z-axis is fixed at the central circular holes of the upper fixing member 26 on the right side of the Z-axis and the lower fixing member 27 on the right side of the Z-axis, and passes through the stepper motor 29 on the right side of the Z-axis. The climbing member 210 on the right side of the Z-axis is installed on the stepper motor 29 on the right side of the Z-axis and can move up and down under the drive of the stepper motor 29 on the left side of the Z-axis.

[0055] Furthermore, in a preferred embodiment: the Z-axis moving mechanism 2 also includes a first lifting rod 211, a second lifting rod 212 and a print plate fixing frame 213, and the two ends of the first lifting rod 211 and the second lifting rod 212 are respectively fixed in the groove structures on both sides of the Z-axis left climbing member 25 and the Z-axis right climbing member 210, and the Z-axis can be moved up and down under the drive of the Z-axis left climbing member 25 and the Z-axis right climbing member 210, and the print plate fixing frame 213 is assembled in the middle of the first lifting rod 211 and the second lifting rod 212, and moves up and down with the first lifting rod 211 and the second lifting rod 212.

[0056] Further, in a preferred embodiment: the Y-axis moving mechanism 3 includes: a Y-axis left moving component 31, the Y-axis left moving component 31 includes: a Y-axis left optical axis front fixing piece 311, a Y-axis left optical axis rear fixing piece 312, a Y-axis left lead screw front fixing piece 313, a Y-axis left lead screw rear fixing piece 314, a Y-axis left optical axis 315, a Y-axis left lead screw 316, a Y-axis left linear bearing 317, a Y-axis left stepping motor 318 and a Y-axis left connecting piece 319, the Y-axis left optical axis front fixing piece 311 and the Y-axis left lead screw front fixing piece 313 are assembled on the front side of the mounting frame 11 through the through holes thereon, and the Y-axis left optical axis rear fixing piece 312 and the Y-axis left lead screw The rear fixing member 314 of the lever is assembled on the rear side of the mounting frame 11, the left optical axis 315 of the Y-axis passes through the left linear bearing 317 of the Y-axis and is fixed in the middle circular hole of the front fixing member 311 of the Y-axis and the rear fixing member 312 of the left optical axis of the Y-axis, the left lead screw 316 of the Y-axis passes through the left stepping motor 318 of the Y-axis and is fixed in the middle circular hole of the front fixing member 313 of the Y-axis and the rear fixing member 314 of the left lead screw of the Y-axis, the upper part of the left connecting member 319 of the Y-axis is connected to the left linear bearing 317 of the Y-axis, and the lower part is connected to the left stepping motor 318 of the Y-axis. Driven by the left stepping motor 318 of the Y-axis, the left connecting member 319 of the Y-axis can realize forward and backward movement in the direction of the Y-axis.

[0057] Further, in a preferred embodiment: the Y-axis moving mechanism 3 also includes a Y-axis right moving component 32, the Y-axis right moving component 32 includes: a Y-axis right optical axis front fixing piece 321, a Y-axis right optical axis rear fixing piece 322, a Y-axis right lead screw front fixing piece 323, a Y-axis right lead screw rear fixing piece 324, a Y-axis right optical axis 325, a Y-axis right lead screw 326, a Y-axis right linear bearing 327, a Y-axis right stepping motor 328 and a Y-axis right connecting piece 329, the Y-axis right optical axis front fixing piece 321 and the Y-axis right lead screw front fixing piece 323 are assembled on the front side of the mounting frame 11 through the through holes thereon, and the Y-axis right optical axis rear fixing piece 322 and the Y-axis right lead screw The rear fixing member 324 of the bar is assembled on the rear side of the mounting frame 11, the right optical axis 325 of the Y-axis passes through the right linear bearing 327 of the Y-axis, and is fixed in the middle circular hole of the front fixing member 321 of the Y-axis and the rear fixing member 322 of the Y-axis, the right lead screw 326 of the Y-axis passes through the right stepping motor 328 of the Y-axis, and is fixed in the middle circular hole of the front fixing member 323 of the Y-axis and the rear fixing member 324 of the Y-axis, the upper part of the right connecting member 329 of the Y-axis is connected to the right linear bearing 327 of the Y-axis, and the lower part is connected to the right stepping motor 328 of the Y-axis, and driven by the right stepping motor 328 of the Y-axis, the right connecting member 329 of the Y-axis can realize forward and backward movement in the direction of the Y-axis.

[0058] Further, in a preferred embodiment: the X-axis moving mechanism 4 includes: an X-axis left optical axis fixing member 41, an X-axis right optical axis fixing member 42, an X-axis left lead screw fixing member 43, an X-axis right lead screw fixing member 44, an X-axis optical axis 45, an X-axis lead screw 46, an X-axis linear bearing 47, an X-axis stepper motor 48 and an X-axis connecting member 49, the X-axis left optical axis fixing member 41 and the X-axis left lead screw fixing member 43 are assembled on the Y-axis left connecting member 319 through the through holes thereon, and the X-axis right optical axis fixing member 42 and the X-axis right lead screw fixing member 44 are assembled on the Y-axis left connecting member 319 through the through holes thereon Assembled on the right side connecting piece 329 of the Y-axis, the X-axis optical axis 45 passes through the X-axis linear bearing 47 and is fixed at the middle circular hole of the left side optical axis fixing piece 41 of the X-axis and the right side optical axis fixing piece 42 of the X-axis, the X-axis lead screw 46 passes through the X-axis stepper motor 48 and is fixed at the center circular hole of the left side lead screw fixing piece 43 of the X-axis and the right side lead screw fixing piece 44 of the X-axis, the upper part of the X-axis connecting piece 49 is connected to the X-axis linear bearing 47, and an X-axis stepper motor 48 is installed inside, and driven by the X-axis stepper motor 48, the X-axis connecting piece 49 can realize left and right movement in the X-axis direction.

[0059] Further, in a preferred embodiment: the closed refrigeration mechanism 5 includes: an upper refrigeration unit 51, the upper refrigeration unit 51 includes: an upper refrigeration plate 511, an upper refrigeration fin 512, an upper water-cooled head 513, an upper refrigeration fixing plate 514, an upper heat preservation plate 515, an upper water inlet pipe 516 and an upper water outlet pipe 517, the upper refrigeration plate 511 is installed below the X-axis connecting member 49, the lower side of the upper refrigeration fin 512 is attached to the middle part of the upper refrigeration plate 511, and the upper side is attached to the upper water-cooled head 513, A screw is welded in the middle of the upper refrigeration plate 511, and the upper refrigeration fixing plate 514 is assembled on the screw through the through hole thereon, and the upper refrigeration plate 512 and the upper water-cooling head 513 are fixed on the upper refrigeration plate 511 so that they fit tightly, and the upper insulation plate 515 is assembled above the upper refrigeration plate 511. The water-cooling head has two holes for water inlet and outlet, and the upper water inlet pipe 516 and the upper water outlet pipe 517 are connected to the two holes of the upper water-cooling head 513, and the upper water inlet pipe 516 is on the right, and the upper water outlet pipe 517 is on the left.

[0060] Further, in a preferred embodiment: the closed refrigeration mechanism 5 also includes: a middle refrigeration unit 52, the middle refrigeration unit 52 includes: a middle refrigeration plate 521, a front refrigeration fin 522, a front water-cooled head 523, a front refrigeration fixing plate 524, a front insulation plate 525, a rear refrigeration fin 526, a rear water-cooled head 527, a rear refrigeration fixing plate 528, a rear insulation plate 529, a left refrigeration fin 5210, a left water-cooled head 5211, a left refrigeration fixing plate 5212, a left insulation plate 5213, a right refrigeration fin 5214, a right water-cooled head 5215, a right refrigeration fixing plate 5216 and a right insulation plate 5217, the middle refrigeration plate 521 is equipped with The middle part of the two horizontal bars connecting the left Z-axis frame structure and the right Z-axis frame structure of the mounting frame 11, the middle refrigeration plate 521 is a square structure, and there are two welded screws on the outside of the four directions of the front, rear, left and right sides, one side of the front refrigeration plate 522 is attached to the front side of the middle refrigeration plate 521, and the other side is attached to the front water-cooling head 523, the front refrigeration fixing plate 524 is installed on the screws on the front side of the middle refrigeration plate 521 through the through holes thereon, and fixes the front refrigeration plate 522 and the front water-cooling head 523, the front insulation plate 525 is attached to the front side of the middle refrigeration plate 521, and one side of the rear refrigeration plate 526 is attached to the rear side of the middle refrigeration plate 521, The other side is fitted with the rear water-cooling head 527, the rear refrigeration fixing plate 528 is installed on the screws on the rear side of the middle refrigeration plate 521 through the through holes thereon, and fixes the rear refrigeration plate 526 and the rear water-cooling head 527, the rear insulation plate 529 is fitted on the rear side of the middle refrigeration plate 521, one side of the left refrigeration plate 5210 is fitted with the left side of the middle refrigeration plate 521, and the other side is fitted with the left water-cooling head 5211, the left refrigeration fixing plate 5212 is installed on the screws on the left side of the middle refrigeration plate 521 through the through holes thereon, and fixes the left refrigeration plate 5210 and the left water-cooling head 5211, the left insulation plate 5213 is fitted on the left side of the middle refrigeration plate 521, and the right refrigeration plate 521 One side is attached to the rear side of the middle refrigeration plate 521, and the other side is attached to the right water cooling head 5215. The right refrigeration fixing plate 5216 is installed on the screws on the right side of the middle refrigeration plate 521 through the through holes thereon, and fixes the right refrigeration plate 5214 and the right water cooling head 5215. The right insulation plate 5217 is attached to the right side of the middle refrigeration plate 521. The middle refrigeration unit 52 also includes: a middle water inlet pipe 5218 and a middle water outlet pipe 5219. Both the middle water inlet pipe 5218 and the middle water outlet pipe 5219 are annular tubular structures. The middle water inlet pipe 5218 is connected to the holes on the upper sides of the four middle water cooling heads, and the middle water outlet pipe 5219 is connected to the holes on the lower sides of the four middle water cooling heads.

[0061] Further, in a preferred embodiment: the closed refrigeration mechanism 5 also includes: a lower refrigeration unit 53, the lower refrigeration unit 53 includes: a printing plate 531, a lower refrigeration plate 532, a lower water cooling head 533, a lower refrigeration fixing plate 534, a lower heat preservation plate 535, a lower water inlet pipe 536 and a lower water outlet pipe 537, the printing plate 531 is installed above the printing plate fixing frame 213, two screws are welded below the printing plate 531, and one side of the lower refrigeration plate 532 is connected to the lower refrigeration plate 534. The lower side of the printing plate 531 is attached, and the other side is attached to the lower water-cooling head 533. The lower refrigeration fixing plate 534 is installed on the screws below the printing plate 531 through the through holes thereon, and fixes the lower refrigeration plate 532 and the lower water-cooling head 533. The lower insulation plate 535 is attached to the lower side of the printing plate 531. The lower water inlet pipe 536 and the lower water outlet pipe 537 are connected to the two holes of the lower water-cooling head 533. The lower water inlet pipe 536 is on the right side, and the lower water outlet pipe 537 is on the left side.

[0062] Further, in a preferred embodiment: the closed air cooling mechanism 6 includes: a left air cooler 61 and a right air cooler 62, the left air cooler 61 is installed on the left side of the rear protective plate 16 through the through hole thereon, and the right air cooler 62 is installed on the right side of the rear protective plate 16 through the through hole thereon.

[0063] Further, in a preferred embodiment: the ultraviolet sterilization device 7 includes: an upper left ultraviolet lamp 71, an upper right ultraviolet lamp 72, a lower left ultraviolet lamp 73 and a lower right ultraviolet lamp 74, the upper left ultraviolet lamp 71 is mounted on the upper left beam of the mounting frame 11, the upper right ultraviolet lamp 72 is mounted on the upper right beam of the mounting frame 11, the lower left ultraviolet lamp 73 is mounted on the lower left beam of the mounting frame 11, and the lower right ultraviolet lamp 74 is mounted on the lower right beam of the mounting frame 11.

[0064] Further, in a preferred embodiment: the temperature detection device 8 includes: a cavity temperature sensor 81, a cavity sensor fixing part 82, an air-cooled temperature sensor 83 and an air-cooled sensor fixing part 84, the cavity temperature sensor 81 is installed inside the cavity sensor fixing part 82, the cavity sensor fixing part 82 is fixed on the screws of the upper refrigeration plate 511, the air-cooled temperature sensor 83 is installed inside the air-cooled sensor fixing part 84, and the air-cooled sensor fixing part 84 is installed on the cross bar of the mounting frame 11.

[0065] Furthermore, in a preferred embodiment: the printing nozzle 9 can be an extrusion nozzle device disclosed in the utility model patent CN202220671744.6.

[0066] The above are only preferred embodiments of the present invention, and are not intended to limit the implementation and protection scope of the present invention.

[0067] The present invention also has the following implementation modes based on the above:

[0068] In a further embodiment of the present invention, a specific implementation mode 1: Figure 1-16As shown, a desktop extrusion-type 3D bioprinter with a closed refrigeration chamber in the present embodiment includes a main frame 1, a Z-axis moving mechanism 2, a Y-axis moving mechanism 3, an X-axis moving mechanism 4, a closed refrigeration mechanism 5, an air cooling mechanism 6, an ultraviolet sterilization device 7, a temperature detection device 8 and a printing nozzle 9. The main frame 1 is composed of a mounting frame 11, a left protective plate 12, a right protective plate 13, an upper protective plate 14, a lower protective plate 15, a rear protective plate 16, a front frame plate 17, a front protective plate 18, an upper hinge 19 and a lower hinge 110. The mounting frame 11 is an integral structure. The left protective plate 12 and the right protective plate 13 are assembled on the left and right sides of the mounting frame 11. The upper protective plate 14 and the lower hinge 110 are assembled on the left and right sides of the mounting frame 11. The protective plate 15 is assembled on the upper and lower sides of the mounting frame 11, the rear protective plate 16 and the front frame plate 17 are assembled on the rear and front of the mounting frame 11, the front protective plate 18 is connected to the front frame plate 17 through the upper hinge 19 and the lower hinge 110, the Z-axis moving mechanism 2 includes an upper fixing member 21 on the left side of the Z-axis, a lower fixing member 22 on the left side of the Z-axis, a lead screw 23 on the left side of the Z-axis, a stepper motor 24 on the left side of the Z-axis, a climbing member 25 on the left side of the Z-axis, an upper fixing member 26 on the right side of the Z-axis, a lower fixing member 27 on the right side of the Z-axis, a lead screw 28 on the right side of the Z-axis, a stepper motor 29 on the right side of the Z-axis, a climbing member 210 on the right side of the Z-axis, a first lifting rod 211, a second lifting rod 212 and a printing plate fixing frame 213, an upper fixing member 21 on the left side of the Z-axis and a left The side lower fixing member 22 is respectively assembled on the upper and lower sides of the left Z-axis frame structure of the mounting frame 11, the Z-axis left side lead screw 23 is fixed at the center circular holes of the Z-axis left upper fixing member 21 and the Z-axis left side lower fixing member 22, and passes through the Z-axis left side stepper motor 24, the Z-axis left side climbing member 25 is installed on the Z-axis left side stepper motor 24, the Z-axis right side upper fixing member 26 and the Z-axis right side lower fixing member 27 are respectively assembled on the upper and lower sides of the right Z-axis frame structure of the mounting frame 11, the Z-axis right side lead screw 28 is fixed at the center circular holes of the Z-axis right side upper fixing member 26 and the Z-axis right side lower fixing member 27, and passes through the Z-axis right side stepper motor 29, the Z-axis right side climbing member 210 is installed on the Z-axis right side stepper motor 29, The two ends of the first lifting rod 211 and the second lifting rod 212 are respectively fixed in the groove structures on both sides of the Z-axis left climbing member 25 and the Z-axis right climbing member 210. The printing plate fixing frame 213 is assembled in the middle of the first lifting rod 211 and the second lifting rod 212. The Y-axis moving mechanism 3 includes a Y-axis left moving component 31 and a Y-axis right moving component 32. The Y-axis left moving component 31 includes a Y-axis left optical axis front fixing component 311, a Y-axis left optical axis rear fixing component 312, a Y-axis left lead screw front fixing component 313, a Y-axis left lead screw rear fixing component 314, a Y-axis left optical axis 315, a Y-axis left lead screw 316, a Y-axis left linear bearing 317, a Y-axis left stepping motor 318 and a Y-axis left connecting component 319.The Y-axis left optical axis front fixing piece 311 and the Y-axis left lead screw front fixing piece 313 are assembled on the front side of the mounting frame 11 through the through holes thereon, the Y-axis left optical axis rear fixing piece 312 and the Y-axis left lead screw rear fixing piece 314 are assembled on the rear side of the mounting frame 11, the Y-axis left optical axis 315 passes through the Y-axis left linear bearing 317 and is fixed at the middle circular hole of the Y-axis left optical axis front fixing piece 311 and the Y-axis left optical axis rear fixing piece 312, the Y-axis left lead screw 316 passes through the Y-axis left stepping motor 318 and is fixed in the middle circular hole of the Y-axis left lead screw front fixing piece 313 and the Y-axis left lead screw rear fixing piece 314, the Y-axis left connecting piece 319 is connected to the Y-axis left linear bearing 317 at the upper part, and to the Y-axis left stepping motor 318 at the lower part. The motor 318 is connected, and the Y-axis right moving assembly 32 includes a Y-axis right optical axis front fixing piece 321, a Y-axis right optical axis rear fixing piece 322, a Y-axis right lead screw front fixing piece 323, a Y-axis right lead screw rear fixing piece 324, a Y-axis right optical axis 325, a Y-axis right lead screw 326, a Y-axis right linear bearing 327, a Y-axis right stepping motor 328 and a Y-axis right connecting piece 329. The Y-axis right optical axis front fixing piece 321 and the Y-axis right lead screw front fixing piece 323 are assembled on the front side of the mounting frame 11 through the through holes thereon, and the Y-axis right optical axis rear fixing piece 322 and the Y-axis right lead screw rear fixing piece 324 are assembled on the rear side of the mounting frame 11. The Y-axis right optical axis 325 passes through the Y-axis right linear bearing 327 and is fixed. At the middle circular hole of the front fixing piece 321 of the right optical axis of the Y-axis and the rear fixing piece 322 of the right optical axis of the Y-axis, the right lead screw 326 of the Y-axis passes through the right stepping motor 328 of the Y-axis and is fixed in the middle circular hole of the front fixing piece 323 of the right lead screw of the Y-axis and the rear fixing piece 324 of the right lead screw of the Y-axis. The upper part of the right connecting piece 329 of the Y-axis is connected with the right linear bearing 327 of the Y-axis. The X-axis moving mechanism 4 includes the left optical axis fixing piece 41 of the X-axis, the right optical axis fixing piece 42 of the X-axis, the left lead screw fixing piece 43 of the X-axis, the right lead screw fixing piece 44 of the X-axis, the X-axis optical axis 45, the X-axis lead screw 46, the X-axis linear bearing 47, the X-axis stepping motor 48 and the X-axis connecting piece 49. The left optical axis fixing piece 41 of the X-axis and the left lead screw fixing piece 4 3 is assembled on the Y-axis left connecting member 319 through the through hole thereon, the X-axis right optical axis fixing member 42 and the X-axis right lead screw fixing member 44 are assembled on the Y-axis right connecting member 329 through the through holes thereon, the X-axis optical axis 45 passes through the X-axis linear bearing 47 and is fixed at the middle circular hole of the X-axis left optical axis fixing member 41 and the X-axis right optical axis fixing member 42, the X-axis lead screw 46 passes through the X-axis stepping motor 48 and is fixed at the center circular hole of the X-axis left lead screw fixing member 43 and the X-axis right lead screw fixing member 44, the upper part of the X-axis connecting member 49 is connected to the X-axis linear bearing 47, and the X-axis stepping motor 48 is installed inside, the closed refrigeration mechanism 5 includes an upper refrigeration unit 51, a middle refrigeration unit 52 and a lower refrigeration unit 53,The upper refrigeration unit 51 includes an upper refrigeration plate 511, an upper refrigeration sheet 512, an upper water-cooled head 513, an upper refrigeration fixing plate 514, an upper heat preservation plate 515, an upper water inlet pipe 516 and an upper water outlet pipe 517. The upper refrigeration plate 511 is installed below the X-axis connecting member 49. The lower side of the upper refrigeration sheet 512 is attached to the middle part of the upper refrigeration plate 511, and the upper side is attached to the upper water-cooled head 513. The upper refrigeration fixing plate 514 is assembled on the screws of the upper refrigeration plate 511 through the through holes thereon. The upper heat preservation plate 515 is assembled above the upper refrigeration plate 511. The upper water inlet pipe 516 and the upper water outlet pipe 517 are connected to the two holes of the upper water-cooled head 513. The upper water inlet pipe 516 is on the right The upper water outlet pipe 517 is on the left side, the middle refrigeration unit 52 includes a middle refrigeration plate 521, a front refrigeration fin 522, a front water-cooling head 523, a front refrigeration fixing plate 524, a front insulation plate 525, a rear refrigeration fin 526, a rear water-cooling head 527, a rear refrigeration fixing plate 528, a rear insulation plate 529, a left refrigeration fin 5210, a left water-cooling head 5211, a left refrigeration fixing plate 5212, a left insulation plate 5213, a right refrigeration fin 5214, a right water-cooling head 5215, a right refrigeration fixing plate 5216, a right insulation plate 5217, a middle water inlet pipe 5218 and a middle water outlet pipe 5219, and the middle refrigeration plate 521 is assembled on the left connecting portion of the mounting frame 11. In the middle part of the two horizontal bars of the side Z-axis frame structure and the right Z-axis frame structure, one side of the front refrigeration plate 522 is attached to the front side of the middle refrigeration plate 521, and the other side is attached to the front water-cooling head 523. The front refrigeration fixing plate 524 is installed on the screws on the front side of the middle refrigeration plate 521 through the through holes thereon. The front insulation plate 525 is attached to the front side of the middle refrigeration plate 521. One side of the rear refrigeration plate 526 is attached to the rear side of the middle refrigeration plate 521, and the other side is attached to the rear water-cooling head 527. The rear refrigeration fixing plate 528 is installed on the screws on the rear side of the middle refrigeration plate 521 through the through holes thereon. The rear insulation plate 529 is attached to the rear side of the middle refrigeration plate 521. One side of the left refrigeration plate 5210 is attached to the middle refrigeration The left side of the plate 521 is attached, and the other side is attached to the left water cooling head 5211. The left refrigeration fixing plate 5212 is installed on the screw on the left side of the middle refrigeration plate 521 through the through hole thereon. The left insulation plate 5213 is attached to the left side of the middle refrigeration plate 521. One side of the right refrigeration plate 5214 is attached to the rear side of the middle refrigeration plate 521, and the other side is attached to the right water cooling head 5215. The right refrigeration fixing plate 5216 is installed on the screw on the right side of the middle refrigeration plate 521 through the through hole thereon. The right insulation plate 5217 is attached to the right side of the middle refrigeration plate 521. The middle water inlet pipe 5218 is connected to the holes on the upper sides of the four middle water cooling heads. The middle water outlet pipe 5219 is connected to the holes on the lower sides of the four middle water cooling heads.The lower refrigeration unit 53 includes a printing plate 531, a lower refrigeration sheet 532, a lower water cooling head 533, a lower refrigeration fixing plate 534, a lower heat preservation plate 535, a lower water inlet pipe 536 and a lower water outlet pipe 537. The printing plate 531 is installed above the printing plate fixing frame 213. One side of the lower refrigeration sheet 532 is attached to the bottom of the printing plate 531, and the other side is attached to the lower water cooling head 533. The lower refrigeration fixing plate 534 is installed on the screws below the printing plate 531 through the through holes thereon. The lower heat preservation plate 535 is installed on the lower water cooling head 533. 35 is attached to the bottom of the printing plate 531, the lower water inlet pipe 536 and the lower water outlet pipe 537 are connected to the two holes of the lower water cooling head 533, the lower water inlet pipe 536 is on the right side, and the lower water outlet pipe 537 is on the left side. The closed air cooling mechanism 6 includes a left air cooling machine 61 and a right air cooling machine 62. The left air cooling machine 61 is installed on the left side of the rear protective plate 16 through the through hole thereon, and the right air cooling machine 62 is installed on the right side of the rear protective plate 16 through the through hole thereon. The ultraviolet sterilization device 7 includes an upper left ultraviolet lamp 71, upper right ultraviolet lamp 72, lower left ultraviolet lamp 73 and lower right ultraviolet lamp 74, upper left ultraviolet lamp 71 is mounted on the upper left beam of the mounting frame 11, upper right ultraviolet lamp 72 is mounted on the upper right beam of the mounting frame 11, lower left ultraviolet lamp 73 is mounted on the lower left beam of the mounting frame 11, and lower right ultraviolet lamp 74 is mounted on the lower right beam of the mounting frame 11. The temperature detection device 8 includes a cavity temperature sensor 81, a cavity sensor fixing part 82, an air-cooled temperature sensor 83 and an air-cooled sensor fixing part 84. The cavity temperature sensor 81 is mounted inside the cavity sensor fixing part 82, the cavity sensor fixing part 82 is fixed on the screw of the upper refrigeration plate 511, the air-cooled temperature sensor 83 is mounted inside the air-cooled sensor fixing part 84, and the air-cooled sensor fixing part 84 is mounted on the crossbar of the mounting frame 11. The print nozzle 9 can be an extrusion nozzle device disclosed in the utility model patent CN202220671744.6. ,

[0069] In a further embodiment of the present invention, specific implementation mode 2; Figure 1 , Fig.13 As shown, the mounting frame 11 is a rigid structure with threaded holes at specific positions for mounting other structures.

[0070] In a further embodiment of the present invention, specific implementation method three; Figure 2 , Figure 3 As shown, the left protective plate 12, the right protective plate 13, the upper protective plate 14, the lower protective plate 15, the rear protective plate 16, the front frame plate 17 and the front protective plate 18 surround the entire printer from six directions: front, back, up, down, left and right, to form an internal space, separating the internal space of the printer from the external space.

[0071] In a further embodiment of the present invention, specific implementation mode 4; Figure 4 , Figure 5 , Figure 6 As shown, the Z-axis moving mechanism 2 can drive the printing plate 531 to move up and down to realize the vertical movement of the printer, the Y-axis moving mechanism 3 can drive the X-axis moving mechanism 4 to move forward and backward in the horizontal direction of the printer, and the X-axis moving mechanism 4 can drive the print head 9 to move left and right in the horizontal direction of the printer. The three mechanisms are combined together to complete the basic movement function of the printer.

[0072] In a further embodiment of the present invention, specific implementation mode 5; Figure 1 , Figure 6 As shown, the upper refrigeration plate 511 of the upper refrigeration unit 51 is installed on the X-axis connecting member 49 of the X-axis moving mechanism 4, and can move in the horizontal direction along with the X-axis moving mechanism 4.

[0073] In a further embodiment of the present invention, specific implementation mode 6; Figure 8 As shown, the upper cooling plate 511, the middle cooling plate 521 and the printing plate 531 are made of materials with good heat conductivity. The upper cooling plate 511 is on the middle cooling plate 521 and the printing plate 531, and the printing plate 531 is embedded in the middle cooling plate 521, forming a closed cavity together. When printing starts, the printing plate 531 is at the highest position and is flush with the upper end of the middle cooling plate 521. After printing starts, the height of the printing plate 531 decreases as the number of printed layers increases.

[0074] In a further embodiment of the present invention, specific implementation mode ten; Figure 7 As shown, the upper insulation plate 515, the front insulation plate 525, the rear insulation plate 529, the left insulation plate 5213, the right insulation plate 5217 and the lower insulation plate 535 are wrapped around the outside of the cavity to play a role in heat preservation.

[0075] In a further embodiment of the present invention, specific implementation mode seven; Figure 7 , Figure 8 As shown, the size of the upper cooling plate 511 is twice the size of the closed cavity formed, ensuring that when the print head 9 of the printer moves to any position of the cavity during printing, the driven upper cooling plate 511 will cover the entire cavity, ensuring the closedness of the cavity.

[0076] In a further embodiment of the present invention, specific implementation mode eight; Figure 8 , Fig. 9As shown, the upper cooling fin 512, the front cooling fin 522, the rear cooling fin 526, the left cooling fin 5210, the right cooling fin 5214 and the lower cooling fin 532 are cooled by thermoelectric cooling. One side of the cooling fin is a cooling surface, which can cool, and the other side will generate heat and is a heating surface. The cooling surfaces of the aforementioned cooling fins are respectively attached to the six surfaces of the cavity, namely the top, bottom, front, back, left and right. The cavity with good heat conductivity dissipates cold air into the internal space.

[0077] In a further embodiment of the present invention, specific implementation method nine; Figure 7 , Figure 8 , Fig. 9 As shown, the upper water-cooling head 513, the front water-cooling head 523, the rear water-cooling head 527, the left water-cooling head 5211, the right water-cooling head 5215 and the lower water-cooling head 533 are in contact with the heating surface of the cooling plate. The cold water circulating internally takes away the heat generated by the heating surface of the cooling plate, thereby reducing the temperature of the cooling plate and preventing the cooling plate from burning due to heat.

[0078] In a further embodiment of the present invention, preferably, the cavity temperature sensor 81 is attached to the upper cooling plate 511 to detect the cavity temperature. When the cavity temperature reaches the set temperature, the cavity temperature sensor 81 sends a signal, and the upper cooling fin 512, the front cooling fin 522, the rear cooling fin 526, the left cooling fin 5210, the right cooling fin 5214 and the lower cooling fin 532 stop working to keep the temperature inside the cavity stable.

[0079] In a further embodiment of the present invention, preferably, the closed air cooling mechanism 6 uses air cooling to lower the temperature inside the printer, thereby cooling the inside of the printer. In addition, the closed air cooling mechanism 6 also plays a role in sterilizing and disinfecting the cavity. Before the printer starts working, alcohol is sprayed inside the cavity to sterilize and disinfect the inside of the cavity. After this process is completed, the closed air cooling mechanism 6 starts working to quickly evaporate the alcohol remaining in the green grapes to avoid affecting the cell activity in the printing experiment.

[0080] In a further embodiment of the present invention, preferably, one side of the air-cooled temperature sensor 83 is in contact with the cross bar of the mounting frame 11, and the other side is exposed to the internal space, thereby detecting the temperature of the internal space of the printer. When the internal temperature of the printer reaches the set temperature, the air-cooled temperature sensor 83 sends a signal, and the left air cooler 61 and the right air cooler 62 stop working, thereby providing a stable low-temperature working environment for the cavity.

[0081] In a further embodiment of the present invention, preferably, the ultraviolet sterilization device 7 plays a role in disinfection and sterilization. Before the printer starts working, the upper left ultraviolet lamp 71, the upper right ultraviolet lamp 72, the lower left ultraviolet lamp 73 and the lower right ultraviolet lamp 74 start working, and the emitted ultraviolet rays disinfect the inside of the printer from the top, bottom, left and right. After the disinfection is completed, the printer starts printing.

[0082] In a further embodiment of the present invention, preferably, there are long grooves on the upper ends of the left protective plate 12, the right protective plate 13 and the upper protective plate 14, which can discharge the wind blown by the closed air cooling mechanism 6 from the upper end of the printer to promote air circulation inside the printer.

[0083] In a further embodiment of the present invention, preferably, a circular through hole is provided on the rear protective plate 16 for passing facilities such as electric wires and water pipes.

[0084] In a further embodiment of the present invention, preferably, the Z-axis left stepper motor 24 and the Z-axis right stepper motor 29 move synchronously, and together drive the printing platform to move up and down along the Z-axis direction.

[0085] In a further embodiment of the present invention, preferably, the Y-axis left stepper motor 318 and the Y-axis right stepper motor 328 move synchronously, and together drive the print head 9 to move forward and backward along the Y-axis direction.

[0086] In a further embodiment of the present invention, preferably, the X-axis connecting member 49 has four holes for fixing the printing nozzle 9 .

[0087] In a further embodiment of the present invention, preferably, there are 8 riveted screws on the upper refrigeration plate 511, the first two screws are connected to the upper refrigeration fixing plate 514 to fix the upper refrigeration plate 512 and the upper water cooling head 513, the two screws in the middle are connected to the cavity sensor fixing part 82 to fix the cavity temperature sensor 81, and the four screws at the rear are fixed to the X-axis connecting part 49.

[0088] In a further embodiment of the present invention, preferably, the upper water inlet pipe 516, the upper water outlet pipe 517, the lower water inlet pipe 536, the lower water outlet pipe 537, the middle water inlet pipe 5218 and the middle water outlet pipe 5219 are hose structures with a certain flexibility.

[0089] The above are only preferred embodiments of the present invention, and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the description and illustrations of the present invention should be included in the protection scope of the present invention.

Claims

1. A desktop extrusion 3D bioprinter with a closed refrigeration chamber, characterized in that: It comprises a Z-axis moving mechanism (2), a Y-axis moving mechanism (3), an X-axis moving mechanism (4), a closed refrigeration mechanism (5), an air cooling mechanism (6), an ultraviolet sterilization device (7), a temperature detection device (8) and a printing nozzle (9) which are arranged inside a main frame (1); The Z-axis moving mechanism (2) is movably connected to the main frame (1) along the vertical direction, the Y-axis moving mechanism (3) is movably connected to the main frame (1) along the front-rear direction, and the X-axis moving mechanism (4) is movably connected to the main frame (1) along the left-right direction; The print head (9) is installed on the X-axis moving mechanism (4), and a closed refrigeration mechanism (5) is arranged around the print head (9). The air cooling mechanism (6) is arranged below the closed refrigeration mechanism (5) and is located on one side of the Z-axis moving mechanism (2). The ultraviolet sterilization device (7) is arranged at the bottom of the main frame (1), and the temperature detection device (8) is arranged around the closed refrigeration mechanism (5).

2. The desktop extrusion 3D bioprinter with a closed refrigeration chamber according to claim 1, characterized in that: The main frame (1) comprises a mounting frame (11), a left side protective plate (12), a right side protective plate (13), an upper protective plate (14), a lower protective plate (15), a rear protective plate (16) and a front frame plate (17); the mounting frame (11) is an integral structure, and has threaded holes for mounting at specific positions thereof; a left Z-axis frame structure and a right Z-axis frame structure are provided on the left and right sides for mounting a Z-axis moving mechanism (2); and the left Z-axis frame structure and the right Z-axis frame structure are connected by two horizontal bars; the left side protective plate (12) is mounted on the left side of the mounting frame (11), the right side protective plate (13) is mounted on the right side of the mounting frame (11), and the upper protective plate (14) is mounted on the top of the mounting frame (11). The lower protective plate (15) is mounted on the bottom of the mounting frame (11), the rear protective plate (16) is mounted on the back of the mounting frame (11), and the front frame plate (17) is mounted on the front of the mounting frame (11); the main frame (1) also includes: a front protective plate (18), an upper hinge (19) and a lower hinge (110), the front frame plate (17) having a through hole for hinge installation, the upper hinge (19) and the lower hinge (110) are installed on the mounting frame (11) through the through hole, the front protective plate (18) is connected to the upper hinge (19) and the lower hinge (110) through a hole-shaped structure, and is installed in front of the mounting frame (11), and together with the protective plates in other directions, forms a closed structure.

3. The desktop extrusion 3D bioprinter with a closed refrigeration chamber according to claim 1, characterized in that: The Z-axis moving mechanism (2) comprises an upper fixing member (21) on the left side of the Z-axis, a lower fixing member (22) on the left side of the Z-axis, a lead screw (23) on the left side of the Z-axis, a stepping motor (24) on the left side of the Z-axis and a climbing member (25) on the left side of the Z-axis; The left upper fixing member (21) of the Z axis and the left lower fixing member (22) of the Z axis are respectively mounted on the upper and lower sides of the left Z axis frame structure of the mounting frame (11) through the through holes thereon; the left lead screw (23) of the Z axis is fixed at the central circular holes of the left upper fixing member (21) of the Z axis and the left lower fixing member (22) of the Z axis, and passes through the left stepping motor (24) of the Z axis; the left climbing member (25) of the Z axis is mounted on the left stepping motor (24) of the Z axis, and can move up and down under the drive of the left stepping motor (24) of the Z axis; The Z-axis moving mechanism (2) further comprises: an upper fixing member (26) on the right side of the Z-axis, a lower fixing member (27) on the right side of the Z-axis, a lead screw (28) on the right side of the Z-axis, a stepping motor (29) on the right side of the Z-axis and a climbing member (210) on the right side of the Z-axis. The upper fixing member (26) on the right side of the Z-axis and the lower fixing member (27) on the right side of the Z-axis are respectively mounted on the upper and lower sides of the inside of the Z-axis frame structure on the right side of the mounting frame (11) through the through holes thereon. The lead screw (28) on the right side of the Z-axis is fixed at the central circular holes of the upper fixing member (26) on the right side of the Z-axis and the lower fixing member (27) on the right side of the Z-axis and passes through the stepping motor (29) on the right side of the Z-axis. The climbing member (210) on the right side of the Z-axis is mounted on the stepping motor (29) on the right side of the Z-axis and can move up and down under the drive of the stepping motor (29) on the left side of the Z-axis. The Z-axis moving mechanism (2) further comprises a first lifting rod (211), a second lifting rod (212) and a printing plate fixing frame (213); the two ends of the first lifting rod (211) and the second lifting rod (212) are respectively fixed in the groove-shaped structures on both sides of the Z-axis left climbing member (25) and the Z-axis right climbing member (210); the Z-axis can be moved up and down driven by the Z-axis left climbing member (25) and the Z-axis right climbing member (210); the printing plate fixing frame (213) is installed in the middle of the first lifting rod (211) and the second lifting rod (212), and moves up and down with the first lifting rod (211) and the second lifting rod (212).

4. The desktop extrusion 3D bioprinter with a closed refrigeration chamber according to claim 1, characterized in that: The Y-axis moving mechanism (3) comprises a Y-axis left side moving assembly (31), and the Y-axis left side moving assembly (31) comprises: a Y-axis left side optical axis front fixing member (311), a Y-axis left side optical axis rear fixing member (312), a Y-axis left side lead screw front fixing member (313), a Y-axis left side lead screw rear fixing member (314), a Y-axis left side optical axis (315), a Y-axis left side lead screw (316), a Y-axis left side linear bearing (317), a Y-axis left side stepping motor (318) and a Y-axis left side connecting member (319); The Y-axis left optical axis front fixing member (311) and the Y-axis left lead screw front fixing member (313) are mounted on the front side of the mounting frame (11) through the through holes thereon, the Y-axis left optical axis rear fixing member (312) and the Y-axis left lead screw rear fixing member (314) are mounted on the rear side of the mounting frame (11), and the Y-axis left optical axis (315) passes through the Y-axis left linear bearing (317) and is fixed at the middle circular hole of the Y-axis left optical axis front fixing member (311) and the Y-axis left optical axis rear fixing member (312). The left side lead screw (316) of the Y-axis passes through the left side stepping motor (318) of the Y-axis and is fixed in the middle circular hole of the front fixing piece (313) of the left side lead screw of the Y-axis and the rear fixing piece (314) of the left side lead screw of the Y-axis. The upper part of the left side connecting piece (319) of the Y-axis is connected to the left side linear bearing (317) of the Y-axis, and the lower part is connected to the left side stepping motor (318) of the Y-axis. Driven by the left side stepping motor (318) of the Y-axis, the left side connecting piece (319) of the Y-axis can realize forward and backward movement in the direction of the Y-axis. The Y-axis moving mechanism (3) also includes a Y-axis right side moving assembly (32), which includes: a Y-axis right side optical axis front fixing member (321), a Y-axis right side optical axis rear fixing member (322), a Y-axis right side lead screw front fixing member (323), a Y-axis right side lead screw rear fixing member (324), a Y-axis right side optical axis (325), a Y-axis right side lead screw (326), a Y-axis right side linear bearing (327), a Y-axis right side stepping motor (328), and a Y-axis right side connecting member (329); The Y-axis right optical axis front fixing member (321) and the Y-axis right lead screw front fixing member (323) are mounted on the front side of the mounting frame (11) through the through holes thereon, the Y-axis right optical axis rear fixing member (322) and the Y-axis right lead screw rear fixing member (324) are mounted on the rear side of the mounting frame (11), and the Y-axis right optical axis (325) passes through the Y-axis right linear bearing (327) and is fixed at the middle circular hole of the Y-axis right optical axis front fixing member (321) and the Y-axis right optical axis rear fixing member (322). The right side lead screw (326) of the Y-axis passes through the right side stepping motor (328) of the Y-axis and is fixed in the middle circular holes of the front fixing piece (323) of the right side lead screw of the Y-axis and the rear fixing piece (324) of the right side lead screw of the Y-axis. The upper part of the right side connecting piece (329) of the Y-axis is connected to the right side linear bearing (327) of the Y-axis, and the lower part is connected to the right side stepping motor (328) of the Y-axis. Driven by the right side stepping motor (328) of the Y-axis, the right side connecting piece (329) of the Y-axis can realize forward and backward movement in the direction of the Y-axis.

5. The desktop extrusion-type 3D bioprinter with a closed refrigeration chamber according to claim 1, characterized in that: The X-axis moving mechanism (4) comprises an X-axis left optical axis fixing member (41), an X-axis right optical axis fixing member (42), an X-axis left lead screw fixing member (43), an X-axis right lead screw fixing member (44), an X-axis optical axis (45), an X-axis lead screw (46), an X-axis linear bearing (47), an X-axis stepping motor (48) and an X-axis connecting member (49); The X-axis left optical axis fixing member (41) and the X-axis left lead screw fixing member (43) are mounted on the Y-axis left connecting member (319) through the through holes thereon, the X-axis right optical axis fixing member (42) and the X-axis right lead screw fixing member (44) are mounted on the Y-axis right connecting member (329) through the through holes thereon, and the X-axis optical axis (45) passes through the X-axis linear bearing (47) and is fixed to the X-axis left optical axis fixing member (41) and the X-axis right optical axis fixing member At the middle circular hole of (42), the X-axis lead screw (46) passes through the X-axis stepping motor (48) and is fixed at the central circular holes of the X-axis left lead screw fixing member (43) and the X-axis right lead screw fixing member (44). The upper part of the X-axis connecting member (49) is connected to the X-axis linear bearing (47), and the right X-axis stepping motor (48) is installed inside. Driven by the X-axis stepping motor (48), the X-axis connecting member (49) can realize left and right movement in the X-axis direction.

6. The desktop extrusion 3D bioprinter with a closed refrigeration chamber according to claim 1, characterized in that: The closed refrigeration mechanism (5) comprises an upper refrigeration unit (51), and the upper refrigeration unit (51) comprises: an upper refrigeration plate (511), an upper refrigeration fin (512), an upper water cooling head (513), an upper refrigeration fixing plate (514), an upper heat preservation plate (515), an upper water inlet pipe (516) and an upper water outlet pipe (517). The upper refrigeration plate (511) is installed below the X-axis connecting member (49), the lower side of the upper refrigeration fin (512) is attached to the middle part of the upper refrigeration plate (511), and the upper side is attached to the upper water cooling head (513). A screw is welded in the middle of the refrigeration plate (511), and the upper refrigeration fixing plate (514) is installed on the screw through the through hole thereon, and the upper refrigeration plate (512) and the upper water cooling head (513) are fixed on the upper refrigeration plate (511). The upper insulation plate (515) is installed above the upper refrigeration plate (511). The water cooling head has two holes for water inlet and water outlet. The upper water inlet pipe (516) and the upper water outlet pipe (517) are connected to the two holes of the upper water cooling head (513), and the upper water inlet pipe (516) is on the right side, and the upper water outlet pipe (517) is on the left side.

7. The desktop extrusion 3D bioprinter with a closed refrigeration chamber according to claim 1, characterized in that: The closed refrigeration mechanism (5) further comprises a middle refrigeration unit (52), which comprises: a middle refrigeration plate (521), a front refrigeration fin (522), a front water-cooling head (523), a front refrigeration fixing plate (524), a front heat-insulating plate (525), a rear refrigeration fin (526), ​​a rear water-cooling head (527), a rear refrigeration fixing plate (528), a rear heat-insulating plate (529), a left refrigeration fin (5210), a left water-cooling head (5211), a left refrigeration fixing plate (5212), a left heat-insulating plate (5213), a right refrigeration fin (5214), a right water-cooling head (5215), a right refrigeration fixing plate (5216), and a right heat-insulating plate (5217); The middle cooling plate (521) is installed in the middle of the two horizontal bars connecting the left Z-axis frame structure and the right Z-axis frame structure of the installation frame (11). The middle cooling plate (521) is a square structure. Two welded screws are respectively provided on the outer sides of the front side, the rear side, the left side and the right side. One side of the front cooling plate (522) is in contact with the front side of the middle cooling plate (521), and the other side is in contact with the front water cooling head (523). The front cooling fixing plate (524) is fixed through the through hole on the front cooling plate (524). The front side cooling plate (522) and the front side water cooling head (523) are fixed on the screws on the front side of the middle cooling plate (521), the front side heat preservation plate (525) is attached to the front side of the middle cooling plate (521), one side of the rear side cooling plate (526) is attached to the rear side of the middle cooling plate (521), and the other side is attached to the rear side water cooling head (527), and the rear side cooling fixing plate (528) is installed on the screws on the rear side of the middle cooling plate (521) through the through holes thereon, and fixes the rear side cooling plate (526) and the rear water cooling head (527), the rear insulation board (529) is attached to the rear side of the middle cooling plate (521), one side of the left cooling plate (5210) is attached to the left side of the middle cooling plate (521), and the other side is attached to the left water cooling head (5211), the left cooling fixing plate (5212) is installed on the screws on the left side of the middle cooling plate (521) through the through hole thereon, and fixes the left cooling plate (5210) and the left water cooling head (5211), the left insulation board (5213) is attached to the left side of the middle refrigeration plate (521), one side of the right refrigeration plate (5214) is attached to the rear side of the middle refrigeration plate (521), and the other side is attached to the right water cooling head (5215), the right refrigeration fixing plate (5216) is installed on the screws on the right side of the middle refrigeration plate (521) through the through holes thereon, and fixes the right refrigeration plate (5214) and the right water cooling head (5215), and the right insulation plate (5217) is attached to the right side of the middle refrigeration plate (521); The middle refrigeration unit (52) further comprises: a middle water inlet pipe (5218) and a middle water outlet pipe (5219), both of which are annular tubular structures, the middle water inlet pipe (5218) is connected to the holes on the upper sides of the four middle water cooling heads, and the middle water outlet pipe (5219) is connected to the holes on the lower sides of the four middle water cooling heads; The closed refrigeration mechanism (5) further comprises: a lower refrigeration unit (53), the lower refrigeration unit (53) comprising: a printing plate (531), a lower refrigeration plate (532), a lower water cooling head (533), a lower refrigeration fixing plate (534), a lower heat preservation plate (535), a lower water inlet pipe (536) and a lower water outlet pipe (537); The printing plate (531) is mounted above the printing plate fixing frame (213), two screws are welded below the printing plate (531), one side of the lower cooling plate (532) is attached to the bottom of the printing plate (531), and the other side is attached to the lower water cooling head (533), the lower cooling fixing plate (534) is mounted on the screws below the printing plate (531) through the through holes thereon, and fixes the lower cooling plate (532) and the lower water cooling head (533), the lower insulation plate (535) is attached to the bottom of the printing plate (531), the lower water inlet pipe (536) and the lower water outlet pipe (537) are connected to the two holes of the lower water cooling head (533), the lower water inlet pipe (536) is on the right side, and the lower water outlet pipe (537) is on the left side.

8. The desktop extrusion 3D bioprinter with a closed refrigeration chamber according to claim 1, characterized in that: The closed air cooling mechanism (6) comprises a left air cooler (61) and a right air cooler (62); the left air cooler (61) is installed on the left side of the rear protective plate (16) through a through hole thereon, and the right air cooler (62) is installed on the right side of the rear protective plate (16) through a through hole thereon.

9. The desktop extrusion 3D bioprinter with a closed refrigeration chamber according to claim 1, characterized in that: The ultraviolet sterilization device (7) comprises an upper left ultraviolet lamp (71), an upper right ultraviolet lamp (72), a lower left ultraviolet lamp (73) and a lower right ultraviolet lamp (74); the upper left ultraviolet lamp (71) is mounted on the upper left crossbeam of the mounting frame (11), the upper right ultraviolet lamp (72) is mounted on the upper right crossbeam of the mounting frame (11), the lower left ultraviolet lamp (73) is mounted on the lower left crossbeam of the mounting frame (11), and the lower right ultraviolet lamp (74) is mounted on the lower right crossbeam of the mounting frame (11).

10. The desktop extrusion 3D bioprinter with a closed refrigeration chamber according to claim 1, characterized in that: The temperature detection device (8) comprises a cavity temperature sensor (81), a cavity sensor fixing member (82), an air-cooling temperature sensor (83) and an air-cooling sensor fixing member (84); the cavity temperature sensor (81) is installed inside the cavity sensor fixing member (82), the cavity sensor fixing member (82) is fixed on the screws of the upper refrigeration plate (511), the air-cooling temperature sensor (83) is installed inside the air-cooling sensor fixing member (84), and the air-cooling sensor fixing member (84) is installed on the cross bar of the mounting frame (11).

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