Rotatable hot roller system and method for continuous fiber 3D printing

Abstract

The rotatable hot roller system and method for continuous fiber 3D printing comprise a fiber tensioning device, the fiber tensioning device is fixed to a gantry printing table cross beam, the gantry printing table cross beam is connected with a force control feedback device, and the bottom of the force control feedback device is connected with a hot pressing device; the force control feedback device comprises a lead screw guide rail, a first stepping motor is connected to the lead screw guide rail, and a sliding block is connected to the lead screw guide rail. The sliding block is connected with the hollow rotating platform and the tension sensor; a pressure sensor is connected between the hollow rotating platform and the hot-pressing device; a second stepping motor for driving the hot-pressing device to rotate is connected above the hollow rotating platform, the lead screw guide rail is connected with a heating block, the heating block is arranged above the hot-pressing device, and a printing nozzle is connected below the heating block; accurate matching of the hot pressing direction and the printing path is achieved through the rotatable hot roller, real-time adjustment of the pressure of the hot roller and the fiber tension force is achieved through the force control feedback device, and the mechanical performance of a printing sample piece is remarkably improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of 3D printing, and in particular relates to a rotatable hot rolling roller system and method for continuous fiber 3D printing. Background Art

[0002] In order to meet the needs of the manufacturing industry to quickly produce complex structures, 3D printing technology has received widespread attention in the industrial field; however, the durability of existing 3D printing materials in engineering applications is insufficient, and the limitations of the hardware performance of 3D printing equipment have made the application of this technology still mainly concentrated in the prototyping stage. In order to expand the 3D printing process to the final product manufacturing stage, high-performance semi-crystalline polymers represented by polyetheretherketone (PEEK), polyetherketoneketone (PEKK) and polyphenylene sulfide (PPS) are gradually becoming the preferred materials for high-performance 3D printing. These materials are suitable for the manufacture of parts in extreme working environments due to their excellent high-temperature stability and mechanical properties, and have good compatibility with existing 3D printing systems.

[0003] At present, the main challenge of high-performance 3D printing technology is its low interlayer bonding strength. In order to improve the mechanical properties of printed parts, researchers have proposed some improvement measures, such as the patent application "A ground simulation experimental device for 3D printing in space environment" (publication number: CN105716892A) for 3D printing in vacuum environment, the patent application "Based on semi-open high-temperature rotary printing device and process" (publication number: CN118163354A) for high-temperature 3D printing, etc., to improve the mechanical properties of printed parts by adjusting the processing environment; in addition, there is another patent application "A deformable hot pressing 3D printing device" (CN112873830A) to introduce a hot roller device to improve the mechanical properties of printed parts by increasing the pressure during the printing process. Although these methods can improve the mechanical properties of 3D printed parts to a certain extent, they have problems such as limited application scenarios and high equipment requirements. The existing hot pressing device uses a fixed hot roller, which limits the direction and path selection of printing, and cannot dynamically adjust the pressure and fiber tension during the printing process, resulting in insignificant improvement in mechanical properties.

[0004] In summary, at present, there is a lack of a printing device that is suitable for a variety of occasions and has low cost, high efficiency and controllability to effectively improve the interlayer bonding performance of 3D printed samples. This technical bottleneck seriously restricts the widespread application of high-performance 3D printing technology in the industrial field, especially in the manufacturing of high-performance parts. Summary of the invention

[0005] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a rotatable hot roller system and method for continuous fiber 3D printing, which realizes precise matching of the hot pressing direction and the printing path through the rotatable hot roller, and realizes real-time adjustment of the hot roller pressure and the fiber tensioning force through the force control feedback device, thereby effectively reducing the defects that may occur during the printing process and significantly improving the mechanical properties of the printed samples.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A rotatable hot roller system for continuous fiber 3D printing includes a fiber tensioning device 1, which is fixed on a gantry printing table beam 2. The gantry printing table beam 2 is connected to a force control feedback device 4 through a connector 3, and a hot pressing device 5 is connected to the bottom of the force control feedback device 4.

[0008] The fiber tensioning device 1 comprises a fixed cylinder 12 , both ends of which are supported on a left fiber support 13 and a right fiber support 14 , and one end of the fixed cylinder 12 is connected to a magnetic damper 15 ; the fixed cylinder 12 is sleeved with a continuous carbon fiber 11 .

[0009] The force control feedback device 4 includes a lead screw guide 42 connected to the connecting member 3, a first stepper motor 41 is connected to the lead screw guide 42, a slider 44 is connected to the lead screw guide 42, and the first stepper motor 41 is used to drive the slider 44 to perform linear motion; the slider 44 is connected to the hollow rotating platform 410 through a first special-shaped sheet metal part 45, and the first special-shaped sheet metal part 45 is connected to the tension sensor 47 through an L-shaped sheet metal part 46; a first pressure sensor 48 and a second pressure sensor 49 are connected between the bottom of the hollow rotating platform 410 and the hot pressing device 5; a second stepper motor 411 is connected above the hollow rotating platform 410, and the second stepper motor 411 drives the rotation of the hot pressing device 5; the lead screw guide 42 is connected to the heating block 413 through the second special-shaped sheet metal part 43, and the heating block 413 and the hollow rotating platform 410 are located on the same axis, and a printing nozzle 412 is connected above the hot pressing device 5 and below the heating block 413.

[0010] The hot pressing device 5 comprises a connecting plate 51 , a U-shaped sheet metal part 52 is connected below the connecting plate 51 , and the U-shaped sheet metal part 52 is connected to a hot rolling roller 53 via a heating rod.

[0011] The hot calendering roller 53 is provided with grooves to fix the position of the fiber when the fiber is turned.

[0012] A method of utilizing a rotatable heated roller system for continuous fiber 3D printing comprises the following steps:

[0013] 1) Generate a printing path for printing a complex structure, and set the corresponding pulse value of the second stepper motor 411 so that it drives the hot pressing device 5 to rotate through the hollow rotating platform 410 when the printing direction changes, so as to achieve effective hot pressing in any printing direction;

[0014] 2) The first stepper motor 41 drives the slider 44 to descend to a certain height, and the initial pressure is monitored by the first pressure sensor 48 and the second pressure sensor 49;

[0015] 3) adjusting the damping size of the magnetic damper 15 so that the continuous fiber 11 is tensioned under the constraint of compaction between the magnetic damper 15 and the hot roller 53, and monitoring the current tension through the tension sensor 47;

[0016] 4) Setting the temperature of the hot roller 53 and the heating block 413 according to the printing requirements;

[0017] 5) Real-time monitoring of printing pressure and fiber tension during printing, and implementation of multi-sensor real-time feedback and closed-loop control based on deep learning;

[0018] 6) Repeat steps 1) to 5) to print the next part.

[0019] The real-time monitoring in step 5) refers to establishing multi-sensor real-time feedback and closed-loop control based on deep learning, establishing the relationship between printing pressure, fiber tension and interlayer shear strength, and finding the optimal mechanical combination.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] Since the rotatable hot rolling roller of the present invention adopts a force-controlled feedback device, through real-time monitoring and closed-loop control of multiple sensors, it can dynamically adjust the hot pressing direction and pressure during the printing process to ensure precise control of the fiber tension. Therefore, it has the advantages of effectively reducing microscopic pores and improving the surface quality and mechanical properties of printed parts. At the same time, the flexibility and manufacturing accuracy during the printing process are greatly improved, reducing the overall manufacturing cost, and providing a new solution for the promotion of high-performance 3D printing in industrial applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the overall structure of the system of the embodiment of the present invention.

[0023] Figure 2 Schematic diagram of a fiber tensioning device according to an embodiment of the present invention.

[0024] Figure 3 Schematic diagram of a force control feedback device according to an embodiment of the present invention.

[0025] Figure 4 Schematic diagram of a hot pressing device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0026] The present invention is described in detail below in conjunction with embodiments and drawings.

[0027] Reference Figure 1 A rotatable hot roller system for continuous fiber 3D printing includes a fiber tensioning device 1, which is fixed on a gantry printing table beam 2. The gantry printing table beam 2 is connected to a force control feedback device 4 through a connecting piece 3, and a hot pressing device 5 is connected to the bottom of the force control feedback device 4. This embodiment has good adaptability and can be quickly installed on different 3D printers to broaden the scope of application.

[0028] Reference Figure 2 The fiber tensioning device 1 comprises a fixed cylinder 12, both ends of which are supported on a left fiber support 13 and a right fiber support 14, and one end of the fixed cylinder 12 is connected to a magnetic damper 15; the fixed cylinder 12 is sleeved with a continuous carbon fiber 11;

[0029] In this embodiment, the magnetic damper 15 is placed on one side of the right fiber support 14. The tension range of the magnetic damper 15 is 20g-300g, and the torque range is 0.002n*m-0.02n*m.

[0030] Reference Figure 3 The force control feedback device 4 includes a lead screw guide 42 connected to the connecting member 3, a first stepper motor 41 is connected to the lead screw guide 42, a slider 44 is connected to the lead screw guide 42, and the first stepper motor 41 is used to drive the slider 44 to perform linear motion; the slider 44 is connected to the hollow rotating platform 410 through a first special-shaped sheet metal part 45, and the first special-shaped sheet metal part 45 is connected to the tension sensor 47 through an L-shaped sheet metal part 46; a first pressure sensor 48 and a second pressure sensor 49 are connected between the bottom of the hollow rotating platform 410 and the hot pressing device 5; a second stepper motor 411 is connected above the hollow rotating platform 410, and the second stepper motor 411 drives the rotation of the hot pressing device 5; the lead screw guide 42 is connected to the heating block 413 through the second special-shaped sheet metal part 43, and the heating block 413 and the hollow rotating platform 410 are located on the same axis, and a printing nozzle 412 is connected above the hot pressing device 5 and below the heating block 413.

[0031] Reference Figure 4 The hot pressing device 5 includes a connecting plate 51, a U-shaped sheet metal part 52 is connected to the bottom of the connecting plate 51, and the U-shaped sheet metal part 52 is provided with holes for installing a temperature sensor and a heating rod; the U-shaped sheet metal part 52 is connected to a hot rolling roller 53 through a heating rod, and a groove is provided on the hot rolling roller 53 to fix the position of the fiber when the fiber turns, thereby ensuring its follow-up performance.

[0032] In this embodiment, the continuous fiber 11 and the thermoplastic material are melt-impregnated in the heating block 413; the melted material is drawn out through the printing nozzle 412 and wrapped around the tension sensor 47 to monitor the current tension; then, the composite material filament passes through the hollow rotating platform 410 and is embedded in the groove of the hot rolling roller 53. Under the heating action of the hot rolling roller 53, the material is melted again and the printing is completed under the pressure of the hot rolling roller 53. The first pressure sensor 48 and the second pressure sensor 49 can monitor the current printing pressure in real time.

[0033] A method of utilizing a rotatable heated roller system for continuous fiber 3D printing comprises the following steps:

[0034] 1) Generate a printing path for printing a complex structure, and set the corresponding pulse value of the second stepper motor 411 so that it drives the hot pressing device 5 to rotate through the hollow rotating platform 410 when the printing direction changes, so as to achieve effective hot pressing in any printing direction;

[0035] 2) The first stepper motor 41 drives the slider 44 to descend to a certain height, and the first pressure sensor 48 and the second pressure sensor 49 monitor whether the initial pressure is appropriate;

[0036] 3) adjusting the damping size of the magnetic damper 15 so that the continuous fiber 11 is tensioned under the constraint of compaction between the magnetic damper 15 and the hot roller 53, and monitoring whether the current tension is appropriate through the tension sensor 47;

[0037] 4) Setting the temperature of the hot roller 53 and the heating block 413 according to the printing requirements;

[0038] 5) Real-time monitoring of printing pressure and fiber tension during printing, and implementation of multi-sensor real-time feedback and closed-loop control based on deep learning;

[0039] 6) Repeat steps 1) to 5) to print the next part.

[0040] The real-time monitoring in step 5) refers to establishing multi-sensor real-time feedback and closed-loop control based on deep learning, establishing the relationship between printing pressure, fiber tension and interlayer shear strength, and finding the optimal mechanical combination.

[0041] In this embodiment, firstly, the printing path is generated and the corresponding parameters of the second stepper motor 411 are set, so that the hot pressing device 5 can rotate effectively in any printing direction; secondly, the initial pressure and fiber tension are monitored and adjusted by adjusting the slider 44 and the magnetic damper 15; then the temperature of the hot roller 53 and the heating block 413 is set, the printing pressure and fiber tension are monitored in real time, and real-time feedback and closed-loop control are achieved by deep learning, and the above steps are repeated to print multiple parts. Compared with the prior art, the present invention realizes flexible adjustment of hot pressing direction, fiber tension and printing pressure through real-time monitoring of multiple sensors, effectively reduces the microscopic pores of the sample, improves the surface quality and mechanical properties, enhances the flexibility and reliability of manufacturing, reduces the manufacturing cost, and provides a new way for rapid manufacturing of high-performance 3D printing.

Claims

1. A rotatable hot roller system for continuous fiber 3D printing, comprising a fiber tensioning device (1), characterized in that: The fiber tensioning device (1) is fixed on a gantry printing platform crossbeam (2), the gantry printing platform crossbeam (2) is connected to a force control feedback device (4) via a connecting piece (3), and a hot pressing device (5) is connected to the bottom of the force control feedback device (4).

2. The system according to claim 1, characterized in that: The fiber tensioning device (1) comprises a fixed cylinder (12), the two ends of which are supported on a left fiber support (13) and a right fiber support (14), and one end of the fixed cylinder (12) is connected to a magnetic damper (15); and the fixed cylinder (12) is sleeved with continuous carbon fibers (11).

3. The system according to claim 1, characterized in that: The force control feedback device (4) comprises a lead screw guide rail (42) connected to the connecting member (3), a first stepper motor (41) connected to the lead screw guide rail (42), a slider (44) connected to the lead screw guide rail (42), and the first stepper motor (41) is used to drive the slider (44) to perform linear motion; the slider (44) is connected to the hollow rotating platform (410) through a first special-shaped sheet metal part (45), and the first special-shaped sheet metal part (45) is connected to the tension sensor (47) through an L-shaped sheet metal part (46); the bottom of the hollow rotating platform (410) and the heat A first pressure sensor (48) and a second pressure sensor (49) are connected between the hot pressing device (5); a second stepper motor (411) is connected above the hollow rotating platform (410), and the second stepper motor (411) drives the rotation of the hot pressing device (5); the lead screw guide rail (42) is connected to the heating block (413) through the second special-shaped sheet metal part (43), and the heating block (413) and the hollow rotating platform (410) are located on the same axis, and a printing nozzle (412) is connected above the hot pressing device (5) and below the heating block (413).

4. The system according to claim 1, characterized in that: The hot pressing device (5) comprises a connecting plate (51), a U-shaped sheet metal part (52) is connected below the connecting plate (51), and the U-shaped sheet metal part (52) is connected to a hot rolling roller (53) via a heating rod.

5. The system according to claim 4, characterized in that: The hot rolling roller (53) is provided with a groove so as to fix the position of the fiber when the fiber is turned.

6. A method for utilizing a rotatable hot roller system for continuous fiber 3D printing according to any one of claims 1 to 5, characterized in that: The following steps are involved: 1) generating a printing path for printing a complex structure, and setting a corresponding pulse value of a second stepper motor (411) so that when the printing direction changes, the hollow rotating platform (410) drives the hot pressing device (5) to rotate, thereby achieving effective hot pressing in any printing direction; 2) The first stepper motor (41) drives the slider (44) to descend to a certain height, and the initial pressure is monitored by the first pressure sensor (48) and the second pressure sensor (49); 3) adjusting the damping size of the magnetic damper (15) so that the continuous fiber (11) is tensioned under the constraint of compaction between the magnetic damper (15) and the hot rolling roller (53), and monitoring the current tension through the tension sensor (47); 4) Setting the temperature of the hot roller (53) and the heating block (413) according to printing requirements; 5) Real-time monitoring of printing pressure and fiber tension during printing, and implementation of multi-sensor real-time feedback and closed-loop control based on deep learning; 6) Repeat steps 1) to 5) to print the next part.

7. The method according to claim 6, characterized in that: The real-time monitoring in step 5) refers to establishing multi-sensor real-time feedback and closed-loop control based on deep learning, establishing the relationship between printing pressure, fiber tension and interlayer shear strength, and finding the optimal mechanical combination.

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