阅读说明：本技术 一种连续纤维增强热塑性复合材料高温3d打印机 (Continuous fiber reinforced thermoplastic composite high-temperature 3D printer ) 是由 田小永 云京新 秦滢杰 高世涛 于 2021-08-13 设计创作，主要内容包括：一种连续纤维增强热塑性复合材料高温3D打印机,包括腔体保温壳体,腔体保温壳体内部连接有升降打印平台,腔体保温壳体内部设有腔体加热单元；腔体保温壳体顶部连接有水平运动机构,水平运动机构上安装有保温板、打印头,保温板与腔体保温壳体的顶部开口配合,使腔体保温壳体组成一个封闭的腔体空间；打印头伸入腔体保温壳体内部；水平运动机构上安装有挤出送丝机构,挤出送丝机构和打印头连接,挤出送丝机构将热塑性树脂丝材和连续纤维送入打印头；本发明通过整机的结构布局来创造低耗费成本的高温恒温打印环境,减小连续纤维增强热塑性复合材料打印过程中的收缩和翘曲,改善层间性能,提高连续纤维增强热塑性复合材料3D打印的成形质量。(A continuous fiber reinforced thermoplastic composite high-temperature 3D printer comprises a cavity heat-insulation shell, wherein a lifting printing platform is connected inside the cavity heat-insulation shell, and a cavity heating unit is arranged inside the cavity heat-insulation shell; the top of the cavity heat-insulation shell is connected with a horizontal movement mechanism, the horizontal movement mechanism is provided with a heat-insulation plate and a printing head, and the heat-insulation plate is matched with the top opening of the cavity heat-insulation shell so that the cavity heat-insulation shell forms a closed cavity space; the printing head extends into the cavity heat-insulating shell; the horizontal movement mechanism is provided with an extrusion wire feeding mechanism which is connected with the printing head and used for feeding the thermoplastic resin wire and the continuous fiber into the printing head; according to the invention, a high-temperature constant-temperature printing environment with low cost is created through the structural layout of the whole machine, the shrinkage and warpage of the continuous fiber reinforced thermoplastic composite material in the printing process are reduced, the interlayer performance is improved, and the forming quality of 3D printing of the continuous fiber reinforced thermoplastic composite material is improved.)

1. The utility model provides a continuous fibers reinforcing thermoplasticity combined material high temperature 3D printer, includes cavity heat preservation casing (7), its characterized in that: a lifting printing platform (5) is connected inside the cavity heat-insulating shell (7), a cavity heating unit (4) is arranged inside the cavity heat-insulating shell (7), a horizontal movement mechanism (2) is connected to the top of the cavity heat-insulating shell (7), a heat-insulating plate (10) and a printing head (6) are mounted on the horizontal movement mechanism (2), and the heat-insulating plate (10) is matched with an opening in the top of the cavity heat-insulating shell (7) to enable the cavity heat-insulating shell (7) to form a closed cavity space; the printing head (6) extends into the cavity heat-insulating shell (7) and is positioned above the lifting printing platform (5); the horizontal movement mechanism (2) is provided with an extrusion wire feeding mechanism (11), the extrusion wire feeding mechanism (11) is connected with the printing head (6), and the extrusion wire feeding mechanism (11) sends the thermoplastic resin wire (12) and the continuous fiber (13) to the printing head (6).

2. The continuous fiber reinforced thermoplastic composite high temperature 3D printer of claim 1, wherein: the horizontal movement mechanism (2) comprises two Y-direction first track ball screw sliding tables (22), two second track ball screw sliding tables (25) and an X-direction third track ball screw sliding table (27), wherein the first track ball screw sliding tables (22) and the second track ball screw sliding tables (25) are connected with the third track ball screw sliding tables (27) through first sliding table adapter bases (21), second sliding table adapter bases (26) to form an H-shaped structural layout; the third linear rail ball screw sliding table (27) is connected with a section bar support (24) through an X-axis rotary joint seat (28), the middle of the section bar support (24) is connected with a heat insulation plate (10), the bottom of the section bar support (24) is connected with a printing head (6), and the top of the section bar support (24) is connected with an extrusion wire feeding mechanism (11).

3. The continuous fiber reinforced thermoplastic composite high temperature 3D printer of claim 1, wherein: the extruding and wire feeding mechanism (11) comprises a pure material extruder (112) and a composite material extruder (115), wherein the inlet of the pure material extruder (112) is connected with a first thermoplastic resin wire (121) through a first pure material resin feeding pipe (116); the inlet of the composite material extruder (115) is connected with a second thermoplastic resin wire material (122) through a first composite material resin feeding pipe (117); the extruding and wire feeding mechanism (11) respectively feeds a first thermoplastic resin wire (121) and a second thermoplastic resin wire (122) into the pure material extruder (112) through a first pure material resin feeding pipe (116) and a first composite material resin feeding pipe (117), and the composite material extruder (115) actively feeds wires and extrudes through a second pure material resin feeding pipe (113) and a second composite material resin feeding pipe (114).

4. The continuous fiber reinforced thermoplastic composite high temperature 3D printer of claim 2, wherein: the printing head (6) comprises a heating block (605), wherein a first throat pipe (604), a second throat pipe (611) and a fiber guide pipe (614) are connected to the heating block (605); the inlet of the first throat pipe (604) is connected with the outlet of a first pneumatic connector (601) through a first radiating pipe (602), the inlet of the first pneumatic connector (601) is connected with the outlet of a pure material extruder (112) through a second pure material resin feeding pipe (113), and the outlet of the first throat pipe (604) is connected with a pure material printing nozzle (606); the inlet of the second throat pipe (611) is connected with the outlet of the second pneumatic joint (613) through a second heat radiation pipe (612), and the inlet of the second pneumatic joint (613) is connected with the outlet of the composite material extruder (115) through a second composite material resin feeding pipe (114); the inlet of the fiber guide pipe (614) is connected with the outlet of a third pneumatic connector (615), and the inlet of the third pneumatic connector (615) is connected with the fiber pipe (111); the outlet of the fiber guide pipe (614), the outlet of the second throat pipe (611) and the composite material printing nozzle (609) are connected; a first heating rod (608) is connected to the heating block (605) close to the outlet of the first throat pipe (604), a second heating rod (610) is connected to the heating block (605) close to the outlet of the fiber guide pipe (614) and the outlet of the second throat pipe (611), a thermocouple (607) is connected to the heating block (605), and two sides of the heating block (605) are connected with a heating block fixing frame (603) and fixed on the profile support (24) through the heating block fixing frame (603); the continuous fiber (13) is passively fed into the printing head (6) through a fiber material pipe (111), and is synchronously and compositely impregnated with the second thermoplastic resin wire (122) in the printing head (6) and then is blended and extruded through a composite material printing nozzle (609) for printing.

5. The continuous fiber reinforced thermoplastic composite high temperature 3D printer of claim 1, wherein: the heat insulation board (10) is made of an aluminum foil shell and a high-density polyurethane core material, and the total thickness is 20 mm.

6. The continuous fiber reinforced thermoplastic composite high temperature 3D printer of claim 1, wherein: the cavity heat-insulating shell (7) is made of an aluminum alloy shell (71), foaming heat-insulating cotton (72), a ceramic fiber blanket (73) and a stainless steel inner container (74) from outside to inside in sequence, and the total thickness is 15-20 mm.

7. The continuous fiber reinforced thermoplastic composite high temperature 3D printer of claim 1, wherein: the cavity heating unit (4) comprises a first heating lamp tube (41) and a second heating lamp tube (45) on the upper layer of the two sides, a third heating lamp tube (42) and a fourth heating lamp tube (44) on the lower layer of the two sides, and a cavity temperature sensor (43) arranged in the cavity heat-insulating shell (7), wherein the four heating lamp tubes are uniformly distributed on the inner walls of the two sides of the cavity heat-insulating shell (7).

8. The continuous fiber reinforced thermoplastic composite high temperature 3D printer of claim 1, wherein: the cavity heat-insulation shell (7) is provided with a front door (3), an electrical cabinet (9) and an operation panel (8), and the top of the cavity heat-insulation shell (7) is connected with a support (1) for supporting thermoplastic resin wires (12) and continuous fibers (13) rotating wheels.

Technical Field

The invention belongs to the technical field of 3D printing, and particularly relates to a continuous fiber reinforced thermoplastic composite high-temperature 3D printer.

Background

A continuous fiber reinforced thermoplastic composite material (CFRTP) is a composite material having high strength, high rigidity, and high toughness, which is produced by a process of melting and impregnating a thermoplastic resin with continuous fibers as a reinforcing material and a thermoplastic resin as a matrix. The continuous fiber reinforced thermoplastic composite material has been widely used in various fields such as automobile industry, aerospace, military industry, electronics and the like due to the characteristics of light weight, high rigidity, high toughness and the like.

The 3D printing technology which is developed rapidly in recent years is an advanced part forming process, has the characteristics of integral forming and no limitation of model complexity, and can manufacture parts with complex structural shapes without any mould. Since the thermoplastic composite material can be made into an amorphous article in a molten state, and can be made into an article in another shape by heating and melting, and can be repeatedly recycled without significant changes in its physical and mechanical properties, a continuous fiber reinforced thermoplastic composite material 3D printing technology has been developed by combining the continuous fiber reinforced thermoplastic composite material with a 3D printing technology. Compared with pure resin and chopped fiber reinforced 3D printing parts, the continuous fiber reinforced thermoplastic composite material 3D printing technology introduces continuous fibers as a reinforcing phase, and can obviously improve the mechanical properties of the printing parts. However, the 3D printing technology realizes forming by stacking of multiple layers of materials, the problem of warping and layering often exists in the printing process, and the introduction of continuous fibers improves the mechanical properties of the product along the fiber direction, but also weakens the interlayer properties to a certain extent, aggravates the anisotropy of the mechanical properties of the 3D printed product, and limits the application of the continuous fiber reinforced thermoplastic composite material 3D printing technology in the key fields of aerospace, national defense and the like.

So far, most of the ways of improving the warpage and delamination of 3D printed products are only for low-melting-point thermoplastic resin materials, such as polylactic acid, polypropylene, polycarbonate, nylon 6, nylon 12, and the like, and a printing platform is usually adopted to preheat and seal a printing cavity, so that a very obvious improvement effect can be achieved. The 3D printing aiming at high-temperature-resistant high-performance thermoplastic resin materials is difficult to improve, such as polyetheretherketone, polyetherketoneketone, polyphenylene sulfide and other high-performance semi-crystalline polymers, and most of the high-performance thermoplastic resin materials are characterized in that the crystallization melting temperature is far higher than the glass transition temperature, most of mechanical properties can be still maintained even above the glass transition temperature, and the upper limit of the use temperature is much higher than the glass transition temperature. Such high melting point semi-crystalline thermoplastic resin materials are more likely to shrink and warp during printing, and because the temperature difference between the molten material just extruded from the nozzle and the solidified and formed material of the previous layer is too large, the two materials cannot realize good melt bonding, so that the interlayer bonding performance is poor.

At present, for 3D printing of high-melting-point semi-crystalline thermoplastic resin materials, a cavity preheating mode is mostly adopted to reduce the temperature difference between a printing environment and an extruded material, but because a motion mechanism of 3D printing equipment cannot work in a closed high-temperature environment for a long time, the ambient temperature which can be reached by the current cavity preheating is not high, the service performance of the motion mechanism and the closed high-temperature cavity environment form a pair of contradiction points, people often need to consume a high cost to coordinate the contradiction, for example, a high-temperature-resistant motor and a transmission part are adopted, so that the cost of the equipment is greatly increased. And the improvement measures are only aiming at 3D printing of high-melting-point semi-crystalline thermoplastic resin pure materials, but the problems of warping and layering are more prominent for continuous fiber reinforced thermoplastic composite materials, and no good solution exists so far.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide a continuous fiber reinforced thermoplastic composite material high-temperature 3D printer, which creates a high-temperature constant-temperature printing environment with low cost through the structural layout design of the whole machine, so as to reduce the shrinkage and warpage of the continuous fiber reinforced thermoplastic composite material in the printing process, improve the interlayer performance and improve the forming quality of the continuous fiber reinforced thermoplastic composite material 3D printing.

In order to achieve the purpose, the invention is realized by adopting the following technical scheme:

a continuous fiber reinforced thermoplastic composite high-temperature 3D printer comprises a cavity heat-insulation shell 7, wherein a lifting printing platform 5 is connected inside the cavity heat-insulation shell 7, and a cavity heating unit 4 is arranged inside the cavity heat-insulation shell 7; the top of the cavity heat-insulating shell 7 is connected with a horizontal movement mechanism 2, the horizontal movement mechanism 2 is provided with a heat-insulating plate 10 and a printing head 6, and the heat-insulating plate 10 is matched with an opening at the top of the cavity heat-insulating shell 7, so that the cavity heat-insulating shell 7 forms a closed cavity space; the printing head 6 extends into the cavity heat-insulating shell 7 and is positioned above the lifting printing platform 5; the horizontal movement mechanism 2 is provided with an extrusion wire feeding mechanism 11, the extrusion wire feeding mechanism 11 is connected with the printing head 6, and the extrusion wire feeding mechanism 11 feeds the thermoplastic resin wire 12 and the continuous fiber 13 into the printing head 6.

The horizontal movement mechanism 2 comprises two Y-direction first wire rail ball screw sliding tables 22, two second wire rail ball screw sliding tables 25 and an X-direction third wire rail ball screw sliding table 27, and the first wire rail ball screw sliding tables 22 and the second wire rail ball screw sliding tables 25 are connected through a first sliding table adapter base 21, a second sliding table adapter base 26 and the third wire rail ball screw sliding tables 27 to form an H-shaped structural layout; the third linear rail ball screw sliding table 27 is connected with the section bar bracket 24 through an X-axis rotary joint seat 28, the middle part of the section bar bracket 24 is connected with the heat insulation plate 10, the bottom of the section bar bracket 24 is connected with the printing head 6, and the top of the section bar bracket 24 is connected with the extrusion wire feeding mechanism 11.

The extruding wire feeder 11 comprises a pure material extruder 112 and a composite material extruder 115, wherein the inlet of the pure material extruder 112 is connected with a first thermoplastic resin wire 121 through a first pure material resin feeding pipe 116; the inlet of the composite extruder 115 is connected with the second thermoplastic resin filament 122 through a first composite resin feed pipe 117; the extrusion wire feeder 11 feeds the first thermoplastic resin wire 121 and the second thermoplastic resin wire 122 to the virgin material extruder 112 through the first virgin material resin feed pipe 116 and the first composite material resin feed pipe 117, and the composite material extruder 115 actively feeds and extrudes the virgin material resin wire through the second virgin material resin feed pipe 113 and the second composite material resin feed pipe 114.

The printing head 6 comprises a heating block 605, wherein a first throat pipe 604, a second throat pipe 611 and a fiber guide pipe 614 are connected to the heating block 605; the inlet of the first throat pipe 604 is connected with the outlet of the first pneumatic connector 601 through the first radiating pipe 602, the inlet of the first pneumatic connector 601 is connected with the outlet of the pure material extruder 112 through the second pure material resin feeding pipe 113, and the outlet of the first throat pipe 604 is connected with the pure material printing nozzle 606; the inlet of the second throat pipe 611 is connected with the outlet of the second pneumatic joint 613 through a second heat radiation pipe 612, and the inlet of the second pneumatic joint 613 is connected with the outlet of the composite material extruder 115 through a second composite material resin feeding pipe 114; the inlet of the fiber guide tube 614 is connected with the outlet of a third pneumatic connector 615, and the inlet of the third pneumatic connector 615 is connected with the fiber tube 111; the outlet of the fiber guide tube 614, the outlet of the second throat 611 and the composite printing nozzle 609 are connected; a first heating rod 608 is connected to the heating block 605 close to the outlet of the first throat pipe 604, a second heating rod 610 is connected to the heating block 605 close to the outlet of the fiber guide pipe 614 and the outlet of the second throat pipe 611, a thermocouple 607 is connected to the heating block 605, and two sides of the heating block 605 are connected with a heating block fixing frame 603 and fixed on the section bar bracket 24 through the heating block fixing frame 603; the continuous fiber 13 is fed into the printing head 6 through the fiber tube 111 passively, and is co-impregnated with the second thermoplastic resin filament 122 inside the printing head 6 synchronously and then is co-extruded through the composite material printing nozzle 609 for printing.

The heat insulation board 10 is made of an aluminum foil shell and a high-density polyurethane core material, and the total thickness is 20 mm.

The cavity heat-insulating shell 7 is made of an aluminum alloy shell 71, foamed heat-insulating cotton 72, a ceramic fiber blanket 73 and a stainless steel liner 74 in sequence from outside to inside, and the total thickness is 15-20 mm.

The cavity heating unit 4 comprises a first heating lamp 41 and a second heating lamp 45 on the upper layer of the two sides, a third heating lamp 42 and a fourth heating lamp 44 on the lower layer, and a cavity temperature sensor 43 installed in the cavity heat-insulating shell 7, wherein the four heating lamps are uniformly distributed on the inner walls of the two sides of the cavity heat-insulating shell 7.

The cavity heat-insulating shell 7 is provided with a main door 3, an electrical cabinet 9 and an operating panel 8, and the top of the cavity heat-insulating shell 7 is connected with a bracket 1 for supporting thermoplastic resin wires 12 and a continuous fiber 13 rotating wheel.

The invention has the following beneficial effects:

the invention solves the contradiction between the horizontal movement mechanism 2 and the cavity heat-insulating shell 7 through the structural design of the whole machine, realizes the separation and heat insulation of the horizontal movement mechanism 2 and the cavity heat-insulating shell 7 through the heat-insulating plate 10 which follows the printing head 6, does not need to adopt a high-temperature resistant motor, a transmission part and the like with high cost, creates a high-temperature constant-temperature printing environment with low cost, reduces the shrinkage and the warping of a continuous fiber reinforced thermoplastic composite material sample piece in the printing process, reduces the temperature difference among materials, improves the interlayer combination, and further improves the forming quality of the 3D printing of the continuous fiber reinforced thermoplastic composite material.

Drawings

Fig. 1 is a schematic view of the overall structure of the present invention.

Fig. 2 is a schematic structural diagram of the horizontal movement mechanism of the present invention.

FIG. 3 is a schematic view of an extrusion wire feeder according to the present invention.

FIG. 4 is a schematic diagram of a printhead according to the present invention.

FIG. 5 is a schematic diagram of a preheating layout of a high temperature chamber according to the present invention.

FIG. 6 is a schematic view of the composition of the cavity thermal insulation casing material of the present invention.

Detailed Description

The following description of the embodiments of the present invention with reference to the drawings is provided to assist the reader in understanding the basic principles and operational steps of the present invention, and it is to be understood that the scope of the present invention is not limited to the specific statements and embodiments set forth herein. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without inventive step, are still within the scope of the present invention.

Referring to fig. 1, the continuous fiber reinforced thermoplastic composite high-temperature 3D printer comprises a cavity heat-insulation shell 7, wherein a lifting printing platform 5 is connected inside the cavity heat-insulation shell 7, a cavity heating unit 4 is arranged inside the cavity heat-insulation shell 7, and the cavity heating unit 4 heats the cavity heat-insulation shell 7; the top of the cavity heat-insulation shell 7 is connected with a horizontal movement mechanism 2, the horizontal movement mechanism 2 is provided with a heat-insulation plate 10 and a printing head 6, the heat-insulation plate 10 is matched with an opening at the top of the cavity heat-insulation shell 7, so that the cavity heat-insulation shell 7 forms a closed cavity space, the plane size of the heat-insulation plate 10 is larger than the size of the opening at the top of the cavity heat-insulation shell 7, and the heat-insulation plate 10 can always cover the opening at the top of the cavity heat-insulation shell 7 within the effective movement stroke of the printing head 6; the printing head 6 extends into the cavity heat-insulating shell 7 and is positioned above the lifting printing platform 5; the horizontal movement mechanism 2 is provided with an extrusion wire feeding mechanism 11, the extrusion wire feeding mechanism 11 is connected with the printing head 6, and the extrusion wire feeding mechanism 11 feeds the thermoplastic resin wire 12 and the continuous fiber 13 into the printing head 6.

The cavity heat-insulation shell 7 is provided with the main door 3, so that an operator can conveniently open and close the main door 3 to take a piece and observe the printing state in the cavity; an electrical cabinet 9 is arranged on the right side of the cavity heat-preservation shell 7, so that an operator can conveniently overhaul hardware circuit faults and expand hardware, a heat-insulation interlayer is arranged between the electrical cabinet 9 and the cavity heat-preservation shell 7, and normal use of electronic components on the other side is not influenced when the temperature of the cavity is raised; an operation panel 8 is arranged on the right side of the front face of the cavity heat-insulating shell 7, so that man-machine interaction is facilitated, printing tasks are better processed, and state monitoring is better performed; the top of the cavity heat-insulating shell 7 is connected with a bracket 1 for supporting thermoplastic resin wires 12 and a continuous fiber 13 rotating wheel.

Referring to fig. 2, the horizontal movement mechanism 2 includes two first and second linear ball screw sliding tables 22 and 25 in the Y direction and a third linear ball screw sliding table 27 in the X direction, and the first and second linear ball screw sliding tables 22 and 25 are connected to each other through a first sliding table adapter base 21, a second sliding table adapter base 26 and the third linear ball screw sliding table 27 to form an H-shaped structural layout; the third linear rail ball screw sliding table 27 is connected with the section bar bracket 24 through an X-axis rotary joint seat 28, the middle part of the section bar bracket 24 is connected with the heat insulation plate 10, the bottom of the section bar bracket 24 is connected with the printing head 6, and the top of the section bar bracket 24 is connected with the extrusion wire feeding mechanism 11.

Referring to fig. 3, the extrusion wire feeder 11 includes a pure material extruder 112, a composite material extruder 115, one inlet of the pure material extruder 112 is connected with the continuous fiber 13 through a fiber material pipe 111, and the other inlet of the pure material extruder 112 is connected with a first pure material resin wire 121 through a first pure material resin feeding pipe 116; the inlet of the composite extruder 115 is connected with the second thermoplastic resin filament 122 through a first composite resin feed pipe 117; the extrusion wire feeder 11 feeds the first thermoplastic resin wire 121 and the second thermoplastic resin wire 122 to the virgin material extruder 112 through the first virgin material resin feed pipe 116 and the first composite material resin feed pipe 117, and the composite material extruder 115 actively feeds and extrudes the virgin material resin wire through the second virgin material resin feed pipe 113 and the second composite material resin feed pipe 114.

Referring to fig. 4, the print head 6 includes a heating block 605, a first throat 604, a second throat 611, and a fiber guide tube 614 are connected to the heating block 605; the inlet of the first throat pipe 604 is connected with the outlet of the first pneumatic connector 601 through the first radiating pipe 602, the inlet of the first pneumatic connector 601 is connected with the outlet of the pure material extruder 112 through the second pure material resin feeding pipe 113, and the outlet of the first throat pipe 604 is connected with the pure material printing nozzle 606; the inlet of the second throat pipe 611 is connected with the outlet of the second pneumatic joint 613 through a second heat radiation pipe 612, and the inlet of the second pneumatic joint 613 is connected with the outlet of the composite material extruder 115 through a second composite material resin feeding pipe 114; the inlet of the fiber guide tube 614 is connected with the outlet of a third pneumatic connector 615, and the inlet of the third pneumatic connector 615 is connected with the fiber tube 111; the outlet of the fiber guide tube 614, the outlet of the second throat 611 and the composite printing nozzle 609 are connected; a first heating rod 608 for heating the first throat pipe 604 is connected to the heating block 605 close to the outlet of the first throat pipe 604, a second heating rod 610 for heating the fiber guide pipe 614 and the second throat pipe 611 is connected to the heating block 605 close to the outlet of the fiber guide pipe 614 and the outlet of the second throat pipe 611, a thermocouple 607 is connected to the heating block 605, and two sides of the heating block 605 are connected with a heating block fixing frame 603 and fixed on the profile bracket 24 through the heating block fixing frame 603; the continuous fiber 13 is fed into the printing head 6 through the fiber tube 111 passively, and is co-impregnated with the second thermoplastic resin filament 122 inside the printing head 6 synchronously and then is co-extruded through the composite material printing nozzle 609 for printing.

Referring to fig. 5, the cavity heating unit 4 includes a first heating lamp 41 and a second heating lamp 45 on the upper layer of the two sides, a third heating lamp 42 and a fourth heating lamp 44 on the lower layer, and a cavity temperature sensor 43 installed in the cavity heat-insulating housing 7, the heating lamps are 500W iodine-tungsten lamps, the four heating lamps are uniformly distributed on the inner walls of the two sides of the cavity heat-insulating housing 7, and the real-time ambient temperature of the cavity is fed back to the temperature control system through the cavity temperature sensor 43.

Referring to fig. 6, the cavity thermal insulation shell 7 is made of an aluminum alloy shell 71, foamed thermal insulation cotton 72, a ceramic fiber blanket 73 and a stainless steel liner 74 in sequence from outside to inside, and the total thickness is 15-20 mm; the stainless steel has good heat resistance, and the heat preservation performance is superior to that of aluminum alloy, so the stainless steel is adopted as the inner container of the cavity body to directly bear the high-temperature irradiation of the heating lamp tube; the ceramic fiber blanket 73 is tightly attached to the stainless steel inner container 74, the heat insulation and flame retardant effects are good, the ceramic fiber blanket can resist the high temperature of 1000 ℃ at most, the outer side of the ceramic fiber blanket 73 is provided with the foaming heat preservation cotton 72, and the outer side of the foaming heat preservation cotton 72 adopts the aluminum alloy shell 71 for keeping and fixing the internal heat insulation material.

The heat insulation board 10 is made of an aluminum foil shell and a high-density polyurethane core material, the total thickness is 20mm, the total weight is light, and the movement precision of the horizontal movement mechanism 2 is not influenced.

The working principle of the invention is as follows: the cavity heating unit 4 heats the cavity heat-insulating shell 7, the heat-insulating plate 10 can always cover the top opening of the cavity heat-insulating shell 7, and the extruding and wire-feeding mechanism 11 sends the thermoplastic resin wire 12 and the continuous fiber 13 to the printing head 6 to print on the lifting printing platform 5; in the printing process, the cavity heat-insulating shell 7, the heat-insulating plate 10 and the cavity heating unit 4 have comprehensive effects, and a high-temperature constant-temperature printing environment is provided, so that the shrinkage and warpage of the continuous fiber reinforced thermoplastic composite material in the printing process are reduced, the interlayer performance is improved, and the 3D printing forming quality of the continuous fiber reinforced thermoplastic composite material is improved.