Surface treatment process and system for continuous fiber 3D printed components

Abstract

The present application relates to the technical field of composite material additive manufacturing, and in particular to a surface treatment process and system for continuous fiber 3D printed components, which comprises five steps of down pressure optimization in the G code programming stage, light-cold synergistic curing in the real-time printing stage, resin impregnation after printing, two-degree-of-freedom rotary light curing and vibration polishing; the system comprises a two-degree-of-freedom rotary light curing device and a vibration polishing device adapted to the process, the two-degree-of-freedom rotary light curing device realizes equivalent light curing of each part of the component, and the vibration polishing device completes gradient modification through a mixed abrasive head. The present application forms a systematic solution from the printing source, real-time printing and subsequent post-processing, solves the problems of excessive surface roughness, fiber exposure, interlayer defects and post-processing damage to the mechanical properties of the component in the prior art, adapts to the characteristics of thermosetting materials, takes into account the surface finish and fiber integrity, improves the structural strength and reliability of the component, and reduces production costs.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing technology for composite materials, and specifically to a surface treatment process and system for continuous fiber 3D printed components. Background Technology

[0002] Continuous fiber reinforced composite 3D printing technology has developed rapidly in recent years and has shown broad application prospects in many fields. However, the components printed by this technology generally have significant surface quality problems. The core contradictions are the interlayer step effect and roughness, fiber exposure and interface defects, and the limitations of traditional post-processing.

[0003] In existing technologies, during the molding process, the step texture is formed by the layer-by-layer stacking of components, resulting in excessive surface roughness of the printed parts, which makes it difficult to meet the requirements of industrial applications. In order to improve the performance of the components, materials such as continuous fibers are introduced, but the surface roughness problem is further aggravated due to the increased complexity of the process. At the same time, insufficient wetting of fibers and resin can easily lead to exposed surface fibers and reduced precision.

[0004] Furthermore, traditional post-processing methods such as mechanical polishing involve manual polishing, which can easily cause fiber breakage and damage the mechanical properties of the components.

[0005] Meanwhile, existing technologies also have many shortcomings in terms of impregnation technology improvement: for example, in the Chinese patent application No. CN201810282910.1, "A method and apparatus for preparing 3D printing filaments of continuous fiber reinforced resin matrix composite material", the pre-impregnation technology is used to fully impregnate the resin and continuous fiber before printing, but the actual test shows that there is still local impregnation failure in the bending path of the continuous fiber; in terms of post-processing innovation attempts, the resin coating is used to fill the surface pits in the experiment, but it increases the weight by about 10% and reduces the dimensional accuracy.

[0006] The analysis by Xing Yue et al. (Journal of Composite Materials, 2023) points out that many process problems, such as post-processing of parts, still need to be addressed, which are also the main bottlenecks for the technology to truly move towards engineering applications.

[0007] Therefore, developing a systematic treatment solution that adapts to the properties of thermosetting materials and balances surface smoothness and fiber integrity has become a technological gap that the industry urgently needs to overcome. Summary of the Invention

[0008] To address the technical problems of excessive surface roughness, exposed fibers, interlayer delamination, and structural deformation in existing continuous fiber 3D printed components, as well as the tendency of traditional post-processing to damage the mechanical properties of components, insufficient impregnation, uneven curing, and resin waste, this invention provides a surface treatment process and system for continuous fiber 3D printed components. This system achieves systematic optimization from the printing source to post-processing, adapts to the characteristics of thermosetting materials, balances the surface smoothness, structural strength, and fiber integrity of components, reduces production costs, meets industrial application requirements, and breaks through the bottleneck of the engineering application of this technology.

[0009] The technical problem to be solved by this invention is achieved through the following technical solution: On one hand, the present invention provides a surface treatment process for continuous fiber 3D printed components, comprising the following steps: Step 1: In the G-code writing stage, for high-stress fiber areas such as curved surface inflection points and thin-walled edges, set two adjacent path nodes before and after the preset inflection point coordinates, and embed three equal-parameter downward pressure commands respectively to ensure that the interlayer resin is fully bonded. Step 2: During the real-time printing stage, "light-cold" curing and multi-parameter dynamic control are implemented simultaneously through the light-curing component and the air-cooling component: During the printing process, the light-curing component starts in-situ ultraviolet irradiation with a wavelength of 405nm, and the air-cooling component turns on the air pump cooling system to form convection heat dissipation, so that the printhead temperature remains constant after reaching the preset temperature. Step 3: Slowly immerse the printed component into an impregnation tank containing UV-curing resin, and maintain the temperature of the UV-curing resin at 32±2℃ using a constant temperature water bath device; immerse the component in normal atmospheric conditions for 30 minutes, during which time the resin is continuously stirred by a mechanical stirring device to ensure that the component is fully wetted. Step 4: Transfer the fully impregnated component to the two-degree-of-freedom rotational photocuring device, clamp the component with a jig, start the drive motor to rotate the component on both axes, and set the speed to 5-15 rpm; irradiate the rotating component with a continuous spectrum of wavelengths of 385-420 nm emitted by the ultraviolet light component to ensure that all parts of the component receive equivalent light energy input and achieve complete curing; Step 5: Move the cured component into the vibratory grinding device, start the vibration mechanism, and set the vibration frequency to 40-100Hz; after the vibration frequency stabilizes, start the abrasive mechanism, and keep the vibration frequency constant during the grinding process; under the three-dimensional vibration of the vibration mechanism, the grinding head of the abrasive mechanism generates high-frequency micro-amplitude movement to cut and finely polish the surface of the cured component; every 10 minutes during the grinding process, take out the component, blow off the surface debris with compressed air, and weigh it. When the difference between two consecutive weighing results is ≤0.1, the grinding is considered to be over.

[0010] Furthermore, the equal-parameter pressing command in step one controls the print head to perform the same pressing operation at each specified position. The pressing depth is uniformly set to twice the current layer thickness, and the static pressure state is maintained for 800ms after each pressing.

[0011] Furthermore, in step five, the vibratory grinding device uses a grinding head with mixed abrasive particles to achieve gradient trimming of the microstructure on the surface of the component.

[0012] Furthermore, in step three, the light-curing resin is a low-viscosity thermosetting resin with a viscosity controlled between 450 and 550 mPa·s.

[0013] Furthermore, during the photocuring process in step four, the illumination time shall be no less than 20 minutes, provided that the component is rotated biaxially at 5-15 rpm and the ultraviolet light component emits a continuous spectrum of 385-420 nm. For components with complex geometric features such as sharp corners and deep grooves, the light-blocking area can be avoided by adjusting the clamping angle between the fixture and the component, ensuring that the surface and internal gaps of the component receive equivalent light energy without any dead angles.

[0014] On the other hand, the present invention provides a surface treatment system for continuous fiber 3D printed components suitable for the above-mentioned process, including a two-degree-of-freedom rotational photopolymerization device and a vibration grinding device. The two-degree-of-freedom rotational photopolymerization device is used in step four, and the vibration grinding device is used in step five. The two-degree-of-freedom rotational photopolymerization device includes a working box with a placement opening on the front side for picking up and placing components. A rotation clamping assembly is provided inside the working box to clamp and drive the components to rotate at a speed range of 5 to 15 rpm. An ultraviolet light assembly is provided directly above the rotation clamping assembly in the working box. The vibration grinding device includes a vibration mechanism and an abrasive mechanism. The vibration mechanism adopts an axial and radial three-dimensional composite vibration mode with a controllable frequency of 40 to 100 Hz. The grinding head of the abrasive mechanism is configured with a mixture of 50% cylindrical brown fused alumina abrasive grains and 50% spherical brown fused alumina abrasive grains by volume. The cylindrical brown fused alumina abrasive grains are used to quickly remove larger micro-protrusions on the surface of the component, and the spherical brown fused alumina abrasive grains are used to finely polish the surface of the component after cutting.

[0015] Furthermore, the rotary clamping assembly includes a drive motor mounted in the work box via a mounting bracket. The output shaft of the drive motor is connected to a rotary seat, and a left support seat and a right support seat are fixedly connected to the left and right ends of the rotary seat, respectively. A left transmission rod is vertically rotatable on the left side of the left support seat via a bearing, and a left rotating rod is horizontally rotatable on the top of the left support seat via a bearing. A left transmission gear is fixedly fitted at the bottom end of the left transmission rod, a left bevel gear one is fixedly fitted at the top end of the left transmission rod, and a left bevel gear two meshing with the left bevel gear one is fixedly fitted at the left end of the left rotating rod. A right transmission rod is vertically rotatable on the right side of the right support seat via a bearing, and a right rotating rod is horizontally rotatable on the top end of the right support seat via a bearing. A right transmission gear is fixedly fitted at the bottom end of the right transmission rod, a right bevel gear one is fixedly fitted at the top end of the right transmission rod, and a right bevel gear two meshing with the right bevel gear one is fixedly fitted at the right end of the right rotating rod. Clamping components are provided at the right end of the left rotating rod and the left end of the right rotating rod. A central gear that meshes with the left and right transmission gears is fixedly mounted on the top of the drive motor.

[0016] Furthermore, the ultraviolet light assembly includes a heat sink plate disposed on the top surface of the work box and a lamp frame disposed on the top surface of the work box directly above the fixture. A PCB board is disposed on the bottom surface of the heat sink plate, and a number of LED beads are arranged in a rectangular array on the bottom surface of the PCB board. Each LED bead is placed inside the lamp frame, and a convex lens is disposed at the bottom end of the lamp frame corresponding to each LED bead. The number of convex lenses are integrally formed in an array.

[0017] Furthermore, the heat sink includes an integrally formed heat-conducting plate and several heat sinks. The heat sinks are arranged in a straight line at equal intervals on the top surface of the heat-conducting plate, and a cooling fan is also provided on the top surface of the heat sinks for heat dissipation of the LED beads.

[0018] Furthermore, it also includes a conical cylinder located on the top surface of the rotating seat directly below the fixture, and an annular collection box placed on the bottom surface of the work box below the drive motor. The top surface of the conical cylinder has a horn-shaped opening, and arc-shaped guide pipes are fixedly connected to the symmetrical side walls of the conical cylinder. The output end of the arc-shaped guide pipes faces the annular collection box and is used to collect the dripping light-curing resin.

[0019] Compared with the prior art, the present invention has the following beneficial effects: 1. The process of this invention forms a systematic surface treatment solution from three stages: printing source, real-time printing, and subsequent post-processing. In step one, during the G-code writing stage, for high-stress fiber areas such as curved surface inflection points and thin-walled edges, adjacent path nodes are set before and after the preset inflection point coordinates, and three equal-parameter pressing commands are embedded. This enables the print head to perform precise pressing operations at specific positions, effectively enhancing the bonding force of fibers in these key areas, reducing interlayer gaps and stress concentration, and ensuring that the resin fully fills the fiber gaps. This avoids the interlayer peeling and structural deformation problems caused by stress concentration in traditional printing processes, thereby significantly improving the structural strength and reliability of the printed components. In step two, the combination of the photocuring component and the air-cooling component avoids surface unevenness of the printed components due to temperature fluctuations. Steps three, four, and five implement subsequent impregnation, rotational photocuring, and vibration polishing steps to gradually repair surface defects and improve surface smoothness, solving the core problem of poor surface quality in the prior art.

[0020] 2. The thermosetting photocurable resin used in this invention has good fluidity at a suitable temperature, which allows it to penetrate deeper into the micropores of the component. Immersion for 30 minutes under normal atmospheric conditions, combined with continuous stirring of the resin by a mechanical stirring device, makes the resin form a uniform flow in the tank, which further promotes the full contact and penetration of the resin with the component, ensuring that the internal pores of the component are fully filled by the resin.

[0021] 3. The drive motor of this invention drives the rotating seat to rotate. The rotation of the rotating seat drives the left and right support seats to move in a circle around the rotating seat. The left support seat drives the left transmission gear to mesh with the central gear through the left transmission rod, causing it to rotate. The rotation of the left transmission gear, in turn, drives the first left bevel gear to rotate through the left transmission rod. The rotation of the first left bevel gear drives the second left bevel gear to rotate, thereby driving the left rotating rod to rotate. At the same time, the right support seat drives the right transmission gear to mesh with the central gear through the right transmission rod, causing it to rotate. The rotation of the right transmission gear, in turn, drives the right bevel gear through the right transmission rod. When the first wheel rotates, the first right bevel gear rotates, which in turn drives the second right bevel gear to rotate, thereby driving the right rotating rod to rotate. At this time, the left and right rotating rods rotate synchronously, which in turn drives the component clamped in the fixture to rotate uniformly with two degrees of freedom around the left and right rotating rods and the output shaft of the drive motor. In addition, under the illumination of the light source emitted by the lamp beads of the ultraviolet light component, all parts of the component impregnated with thermosetting light-curing resin can receive equivalent light energy input, achieving complete curing and effectively eliminating the problem of uneven curing caused by light attenuation in the traditional static curing method.

[0022] 4. The grinding head of the present invention, with its mixed abrasive particles, drives the abrasive particles to generate high-frequency micro-amplitude motion under the three-dimensional vibration of the vibration mechanism. It rapidly removes larger micro-protrusions on the surface of the component through cylindrical brown fused alumina abrasive particles, and performs fine polishing on the surface of the component after cutting through spherical brown fused alumina abrasive particles. This achieves gradient trimming of the microstructure on the surface of the component. This vibration grinding process is suitable for processing complex curved surface components. It can significantly reduce the surface roughness Ra value while maintaining the dimensional accuracy of the component, making the surface of the component smoother and flatter, and improving the appearance quality and wear resistance of the component.

[0023] 5. The present invention also uses a conical cylinder set on the rotating seat to prevent thermosetting light-curing resin on the component from dripping onto the rotating component through the flared opening on the top surface of the conical cylinder, and collects the dripping resin, and then guides the dripping resin into the annular collection box through the arc-shaped guide tube, so as to realize resin recycling, reduce production costs and reduce pollution. Attached Figure Description

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0025] Figure 1 This is a schematic diagram of the process flow of Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the printing path of the 3D printed sample in Embodiment 1 of the present invention; Figure 3 This is a comparison image of the surface of the control group and the experimental group in Example 1 of the present invention. Figure 4 This is a schematic diagram of the overall structure of the two-degree-of-freedom rotational photocuring device in Embodiment 2 of the present invention; Figure 5 This is a schematic diagram of the overall structure of the rotating clamping assembly according to Embodiment 2 of the present invention; Figure 6 This is a schematic diagram of the overall structure of the ultraviolet light component in Embodiment 2 of the present invention; Figure 7 This is a frontal schematic diagram of the two-degree-of-freedom rotational photocuring device holding the component to be photocured in Embodiment 2 of the present invention; Figure 8 This is another overall structural schematic diagram of the two-degree-of-freedom rotational photocuring device in Embodiment 2 of the present invention.

[0026] Figure label: 1. Working box; 11. Placement opening; 2. Rotary clamping assembly; 21. Drive motor; 22. Rotary seat; 23. Left support seat; 231. Left transmission rod; 232. Left rotating rod; 233. Left transmission gear; 234. Left bevel gear one; 235. Left bevel gear two; 24. Right support seat; 241. Right transmission rod; 242. Right rotating rod; 243. Right transmission gear; 244. Right bevel gear one; 245. Right bevel gear two; 25. Central gear; 3. Ultraviolet light assembly; 31. Heat sink; 311. Heat conduction plate; 312. Heat sink; 32. Lamp frame; 33. PCB board; 34. Lamp bead; 35. Convex lens; 4. Mounting bracket; 5. Conical cylinder; 51. Horn opening; 6. Annular collection box; 7. Arc-shaped guide tube. Detailed Implementation

[0027] To make the technical solution of the present invention clearer and easier to understand, the present invention will be further described in detail below with reference to specific embodiments. It should be noted that these embodiments are only for explaining the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention. Furthermore, the technical features mentioned in the following embodiments can be arbitrarily combined as long as they do not conflict with each other. Example

[0028] Please refer to Figure 1 This embodiment provides a surface treatment process for continuous fiber 3D printed components, and the specific steps are as follows: Step 1: Based on the dedicated slicing software for continuous fiber 3D printing, write G-code. For high stress areas of the fiber, such as curved inflection points and thin-walled edges of the printed component, set an adjacent path node before and after the preset inflection point coordinates, and embed three equal-parameter pressing commands at the two path nodes respectively. Among them, the high-stress area of ​​the fiber is a deformable area caused by physical behaviors such as filament shrinkage and dragging during printing, which can easily lead to shape and size errors and poor surface quality. In this embodiment, please refer to Figure 2 The process involves printing square thin-walled components, with the corners being high-stress fiber areas. Adjacent path nodes are set before and after the preset corner coordinates, and three equal-parameter pressing commands are embedded. The equal-parameter pressing commands control the print head to perform the same pressing operation at each specified position. The pressing depth is uniformly set to twice the current layer thickness. The current printing layer thickness is set to 0.2mm, so the pressing depth is uniformly set to 0.4mm. After each pressing, a static pressure state is maintained for 800ms, which can effectively enhance the bonding force of the fiber in key areas, reduce interlayer gaps, ensure that the resin fully fills the fiber gaps, and ensure that the interlayer resin is fully bonded.

[0029] Step Two: During the real-time printing stage, after the printhead reaches the predetermined temperature, the pre-impregnated filament bundle is fed into the printhead and printed according to the optimized G-code path. During the printing process, the light-curing component and the air-cooling component are activated simultaneously to implement "light-cold" curing and multi-parameter dynamic control. The light-curing component starts in-situ ultraviolet irradiation with a wavelength of 405nm and the irradiation intensity is adjusted to 100mW / cm². The air-cooling component turns on the air pump cooling system to form stable convection heat dissipation and presets the printhead nozzle temperature to 70℃. The temperature sensor monitors the temperature in real time to ensure that the printhead temperature remains constant after reaching 70℃, avoiding surface unevenness caused by temperature fluctuations.

[0030] Step 3: After printing, slowly immerse the component into an impregnation tank containing photocurable resin. The photocurable resin is a low-viscosity thermosetting resin with a viscosity controlled at 500 mPa·s. Use a constant temperature water bath to maintain the temperature of the photocurable resin at 32°C. Immerse the component in the photocurable resin under normal atmospheric conditions for about 30 minutes. During the immersion, use a mechanical stirring device to continuously stir the resin at a speed of 50 r / min to make the resin form a uniform flow in the tank, ensuring that the surface, internal pores and fiber gaps of the component are fully wetted.

[0031] Step 4: After impregnation, slowly remove the component and transfer the fully impregnated component to the two-degree-of-freedom rotational light curing device. Use the clamps (not shown in the figure) inside the device to firmly clamp the component, ensuring that the clamping coaxiality error is ≤0.02mm. Start the drive motor 21 to make the component rotate uniformly in two degrees of freedom at a speed of 10 rpm; Simultaneously, the ultraviolet light component 3 is activated, emitting a continuous ultraviolet spectrum with a wavelength of 400nm. The irradiation intensity is adjusted to 150mW / cm², irradiating the rotating component for 20 minutes to ensure that each part of the component receives equivalent light energy input and achieves complete resin curing.

[0032] During the photocuring process in step four, the illumination time shall be no less than 20 minutes, provided that the component is rotated biaxially at 5-15 rpm and the ultraviolet light component emits a continuous spectrum of 385-420 nm. For components with complex geometric features such as sharp corners and deep grooves, the light-blocking area can be avoided by adjusting the clamping angle between the fixture and the component, so as to ensure that the surface and internal gaps of the component receive equivalent light energy without dead angles.

[0033] Step 5: Move the fully cured component into the vibratory grinding device, start the vibration mechanism, and set the vibration frequency to 70Hz; after the vibration frequency stabilizes, start the abrasive mechanism, and maintain a constant vibration frequency of 70Hz throughout the grinding process; Among them, the abrasive mechanism of the vibratory grinding device achieves gradient trimming of the microstructure on the surface of the component through a grinding head that mixes abrasive particles; Specifically, under the three-dimensional vibration of the vibration mechanism, the grinding head generates high-frequency micro-amplitude motion to cut and finely polish the surface of the component. The grinding time is 15 minutes. After grinding, the component is removed and the surface debris is blown away with compressed air to complete the entire surface treatment process.

[0034] Measured data from a TEAM2022 international conference paper show that, under a typical layer thickness of 0.2 mm, the surface roughness (Ra) of parts printed by fused deposition modeling (FDM) is generally >10 μm, while industrial applications typically require ≤6.3 μm (e.g., in the aerospace field). Please refer to [link / reference needed]. Figure 3 In this embodiment, Figure 3 The image on the left shows the surface of the control group (untreated), and the image on the right shows the surface of the experimental group (treated in this solution). By comparing the surface images of the control group and the experimental group, it is obvious that the surface of the experimental group is smoother and the roughness is significantly reduced compared to the control group. Moreover, there are no exposed fibers or fiber breakage defects on the surface. That is, after testing, the surface roughness Ra of the continuous fiber 3D printed component after treatment in this embodiment is Ra≤5.8μm, which meets the requirements of industrial applications in the aerospace field. The interlayer peel strength of the component is increased by more than 35%, there is no fiber breakage, and the structural strength and reliability are significantly improved. Example

[0035] Please refer to Figures 4-7 This embodiment provides a surface treatment system for continuous fiber 3D printed components suitable for the process of Embodiment 1, including a two-degree-of-freedom rotational photopolymerization device and a vibration grinding device, the specific structure of which is as follows: The two-degree-of-freedom rotational photocuring device includes a working box 1, which is a cuboid structure. The front side of the working box 1 has a placement opening 11 for picking up and putting in components. The working box 1 is equipped with a rotation clamping assembly 2, which is used to clamp and drive the components to rotate. The rotation speed range is 5 to 15 rpm. The working box 1 is equipped with an ultraviolet light assembly 3 directly above the rotation clamping assembly 2. Additionally, an openable and closable sealed door is provided at the placement opening 11 to reduce ultraviolet light leakage and resin volatilization.

[0036] Please refer to Figure 5 and Figure 7The rotary clamping assembly 2 includes a drive motor 21 mounted in the work box 1 via a mounting bracket 4. The output shaft of the drive motor 21 is connected to a rotary seat 22. A left support seat 23 and a right support seat 24 are fixedly connected to the left and right ends of the rotary seat 22, respectively. A left transmission rod 231 is vertically rotatable on the left side of the left support seat 23 via a bearing. A left rotating rod 232 is horizontally rotatable on the top of the left support seat 23 via a bearing. A left transmission gear 233 is fixedly sleeved at the bottom end of the left transmission rod 231. A left bevel gear 234 is fixedly sleeved at the top end of the left transmission rod 231. A rod corresponding to the left bevel gear 234 is fixedly sleeved at the left end of the left rotating rod 232. 4. A left bevel gear 235 is engaged; a right transmission rod 241 is vertically rotatable on the right side of the right support 24 via a bearing, and a right rotating rod 242 is horizontally rotatable on the top of the right support 24 via a bearing. A right transmission gear 243 is fixedly sleeved at the bottom of the right transmission rod 241, and a right bevel gear 244 is fixedly sleeved at the top of the right transmission rod 241. A right bevel gear 245, which meshes with the right bevel gear 244, is fixedly sleeved at the right end of the right rotating rod 242; a clamp (not shown in the figure) for holding components is provided at the right end of the left rotating rod 232 and the left end of the right rotating rod 242. The clamp is used to hold the component after it has been wetted, i.e., the component to be light-cured.

[0037] A central gear 25 is fixedly mounted on the top of the drive motor 21 via a bracket, which meshes with the left transmission gear 233 and the right transmission gear 243 respectively. By achieving the meshing of the central gear 25 with the left and right transmission gears 243, the single drive motor 21 drives the left and right rotating rods 242 to rotate synchronously, thereby causing the clamped component to rotate uniformly with two degrees of freedom around the left and right rotating rods 242 as the axis and around the output shaft of the drive motor 21 as the axis.

[0038] Specifically, the drive motor 21 drives the rotating seat 22 to rotate. This rotation drives the left support seat 23 and the right support seat 24 to move in a circle around the rotating seat 22. The left support seat 23, through the left transmission rod 231, drives the left transmission gear 233 to mesh with the central gear 25 and rotate. The rotation of the left transmission gear 233, in turn, drives the left bevel gear 234 to rotate through the left transmission rod 231. The rotation of the left bevel gear 234 drives the left bevel gear 235 to rotate, thereby driving the left rotating rod 232 to rotate. Simultaneously, the right support seat 24... The right transmission rod 241 drives the right transmission gear 243 to mesh with the center gear 25 and rotate. The rotation of the right transmission gear 243, in turn, drives the right bevel gear 1 244 to rotate through the right transmission rod 241. The rotation of the right bevel gear 1 244 drives the right bevel gear 245 to rotate, thereby driving the right rotating rod 242 to rotate. At this time, the left and right rotating rods 242 rotate synchronously, which in turn drives the clamped fixture to rotate, so that the component to be light-cured can rotate uniformly with two degrees of freedom with the left and right rotating rods 242 as the axis and the output shaft of the drive motor 21 as the axis. Please refer to Figure 6The ultraviolet light component 3 includes a heat sink 31 disposed on the outer top surface of the work box 1, and a lamp frame 32 disposed on the inner top surface of the work box 1 directly above the fixture. The heat sink 31 includes an integrally formed heat-conducting plate 311 and several heat sinks 312 arranged in a straight line at equal intervals. Both the heat-conducting plate 311 and the heat sinks 312 are made of aluminum alloy and have good thermal conductivity. A cooling fan (not shown in the figure) is fixedly mounted on the top surface of the heat sinks 312 by bolts. A PCB board 33 is fixedly mounted on the bottom surface of the heat sink 31. Several LED beads 34 are arranged in a rectangular array on the bottom surface of the PCB board 33. The LED beads 34 are ultraviolet LEDs with a power of 3W / each and an adjustable wavelength of 385~420nm. The lamp frame 32 is a rectangular frame with dimensions matching the PCB board 33. It is fixed to the top surface inside the work box 1. Each lamp bead 34 is placed inside the lamp frame 32, and a convex lens 35 is provided at the bottom of the lamp frame 32 corresponding to each lamp bead 34. The convex lenses 35 are integrally formed in an array to concentrate ultraviolet light and improve the uniformity and intensity of illumination.

[0039] When the cooling fan starts, it generates airflow between adjacent heat sinks 312, dissipating the heat on the heat sinks 312. The heat sinks 312 absorb the heat emitted by the LED beads 34 arranged on the PCB board 33 through the heat conduction plate 311, thereby achieving heat dissipation of the LED beads 34.

[0040] When the component held in the fixture rotates, under the illumination of the light source emitted by the lamp beads 34 of the ultraviolet light component 3, each part of the component impregnated with thermosetting light-curing resin can receive the equivalent light energy input, achieving complete curing and effectively eliminating the problem of uneven curing caused by light attenuation in the traditional static curing method.

[0041] Please refer to Figure 8 In addition, this application also has a resin recycling function, specifically including a conical cylinder 5 that is fixed to the top surface of the rotating seat 22 and located directly below the clamp by bolts. The top surface has a flared opening 51, which can prevent the thermosetting light-cured resin on the component from dripping onto the rotating component, thus ensuring the service life of the device. An annular collection box 6 is placed on the bottom surface of the working box 1 below the drive motor 21. Stainless steel arc-shaped guide pipes 7 are fixedly connected to the symmetrical side walls of the conical cylinder 5 by welding. The output end of the arc-shaped guide pipe 7 faces the annular collection box 6. The arc-shaped guide pipe 7 is used to collect dripping resin and guide it into the annular collection box 6 for recycling.

[0042] When the rotating seat 22 rotates, it will drive the conical cylinder 5 to rotate as well. The rotation of the conical cylinder 5 will drive the arc-shaped guide pipe 7 to rotate around the annular collection box 6, and the output end of the arc-shaped guide pipe 7 will always face the annular collection box 6. At the same time, the rotating conical cylinder 5 has a certain centrifugal force, which can drive the resin to flow into the arc-shaped guide pipe 7 and collect it in the annular collection box 6 through the flow of the arc-shaped guide pipe 7. The collected resin can be reused, reducing production costs and pollution.

[0043] In the prior art, after the component is removed after impregnation, it often needs to stand for 10 minutes to drain the excess resin on the surface before it can be light-cured. The operation is time-consuming and cumbersome. In this application, by setting the conical cylinder 5, the undrained component can be directly rotated for light curing, and the light curing effect is better than the traditional method.

[0044] The vibratory grinding device includes a vibration mechanism and an abrasive mechanism. The vibration mechanism adopts a three-dimensional composite vibration mode with axial and radial directions, and the vibration frequency can be adjusted from 40 to 100 Hz. The grinding head of the abrasive mechanism is equipped with a mixture of cylindrical brown fused alumina abrasive grains (80 to 120 mesh) and spherical brown fused alumina abrasive grains (100 to 140 mesh) with a volume fraction of 50%. The cylindrical brown fused alumina abrasive grains are used to quickly remove larger micro-protrusions on the surface of the component, and the spherical brown fused alumina abrasive grains are used to finely polish the surface of the component after cutting. Both the vibration mechanism and the abrasive mechanism are existing technologies and will not be described in detail here.

[0045] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A surface treatment process for continuous fiber 3D printed components, characterized in that, Includes the following steps: Step 1: In the G-code writing stage, for high-stress fiber areas such as curved surface inflection points and thin-walled edges, set two adjacent path nodes before and after the preset inflection point coordinates, and embed three equal-parameter downward pressure commands respectively to ensure that the interlayer resin is fully bonded. Step 2: During the real-time printing stage, "light-cold" curing and multi-parameter dynamic control are implemented simultaneously through the light-curing component and the air-cooling component: During the printing process, the light-curing component starts in-situ ultraviolet irradiation with a wavelength of 405nm, and the air-cooling component turns on the air pump cooling system to form convection heat dissipation, so that the printhead temperature remains constant after reaching the preset temperature. Step 3: Slowly immerse the printed component into the impregnation tank containing UV-curing resin, and use a constant temperature water bath device to maintain the temperature of the UV-curing resin at 32±2℃. The component was immersed in a normal atmospheric environment for 30 minutes, during which the resin was continuously stirred by a mechanical stirring device to ensure that the component was fully impregnated. Step 4: Transfer the fully impregnated component to the two-degree-of-freedom rotational photocuring device, clamp the component with the clamps, start the drive motor to make the component rotate on both axes, and set the speed to 5-15 rpm; The rotating component is irradiated by emitting a continuous spectrum of wavelengths from 385 to 420 nm using an ultraviolet light component, ensuring that each part of the component receives equivalent light energy input and achieving complete curing. Step 5: Move the cured component into the vibratory grinding device, start the vibration mechanism, and set the vibration frequency to 40-100Hz; after the vibration frequency stabilizes, start the abrasive mechanism, and keep the vibration frequency constant during the grinding process; Under the three-dimensional vibration of the vibration mechanism, the grinding head of the abrasive mechanism generates high-frequency micro-amplitude motion to cut and finely polish the surface of the cured component. During the grinding process, the component is removed every 10 minutes, the surface debris is blown off with compressed air, and then it is weighed. When the difference between two consecutive weighing results is ≤0.1, the grinding is considered to be over.

2. The surface treatment process for continuous fiber 3D printed components according to claim 1, characterized in that, In step one, the equal-parameter pressing command controls the print head to perform the same pressing operation at each specified position. The pressing depth is uniformly set to twice the current layer thickness, and the static pressure state is maintained for 800ms after each pressing.

3. The surface treatment process for continuous fiber 3D printed components according to claim 1, characterized in that, In step five, the vibratory grinding device uses a grinding head with mixed abrasive particles to achieve gradient trimming of the microstructure on the surface of the component.

4. The surface treatment process for continuous fiber 3D printed components according to claim 1, characterized in that, In step three, the light-curing resin is a low-viscosity thermosetting resin with a viscosity controlled between 450 and 550 mPa·s.

5. The surface treatment process for continuous fiber 3D printed components according to claim 1, characterized in that, In the photocuring process in step four, the light exposure time shall be no less than 20 minutes, provided that the component is rotated biaxially at 5-15 rpm and the ultraviolet light component emits a continuous spectrum of 385-420 nm. For components with complex geometric features such as sharp corners and deep grooves, the light-blocking area can be avoided by adjusting the clamping angle between the fixture and the component, so as to ensure that the surface and internal gaps of the component receive the equivalent light energy without any dead angles.

6. A surface treatment system for continuous fiber 3D printed components applicable to the process described in any one of claims 1 to 5, characterized in that, It includes a two-degree-of-freedom rotational photocuring device and a vibratory grinding device. The two-degree-of-freedom rotational photocuring device is used in step four, and the vibratory grinding device is used in step five. The two-degree-of-freedom rotational photocuring device includes a working box, with a placement opening on the front side of the working box for picking up and placing components. A rotation clamping assembly is provided inside the working box, which is used to clamp and drive the components to rotate, with a rotation speed range of 5 to 15 rpm. An ultraviolet light component is provided directly above the rotation clamping assembly in the working box. The vibratory grinding device includes a vibration mechanism and an abrasive mechanism. The vibration mechanism adopts a three-dimensional composite vibration mode with axial and radial directions, and the frequency is controllable from 40 to 100 Hz. The grinding head of the abrasive mechanism is equipped with a mixture of 50% cylindrical brown fused alumina abrasive grains and 50% spherical brown fused alumina abrasive grains by volume. The cylindrical brown fused alumina abrasive grains are used to quickly remove larger micro-protrusions on the surface of the component, and the spherical brown fused alumina abrasive grains are used to finely polish the surface of the component after cutting.

7. The surface treatment system for continuous fiber 3D printed components according to claim 6, characterized in that, The rotary clamping assembly includes a drive motor mounted in the work box via a mounting bracket. The output shaft of the drive motor is connected to a rotary seat, and a left support seat and a right support seat are fixedly connected to the left and right ends of the rotary seat, respectively. A left transmission rod is vertically rotatable on the left side of the left support seat via a bearing, and a left rotating rod is horizontally rotatable on the top of the left support seat via a bearing. A left transmission gear is fixedly sleeved at the bottom of the left transmission rod, a left bevel gear one is fixedly sleeved at the top of the left transmission rod, and a left bevel gear two that meshes with the left bevel gear one is fixedly sleeved at the left end of the left rotating rod. A right transmission rod is vertically rotatable on the right side of the right support seat via a bearing, and a right rotating rod is horizontally rotatable on the top of the right support seat via a bearing. A right transmission gear is fixedly sleeved at the bottom of the right transmission rod, and a right bevel gear one is fixedly sleeved at the top of the right transmission rod. A right bevel gear two that meshes with the right bevel gear one is fixedly sleeved at the right end of the right rotating rod. The right end of the left rotating rod and the left end of the right rotating rod are provided with clamping components, and the top of the drive motor is fixedly equipped with a central gear that meshes with the left drive gear and the right drive gear respectively.

8. The surface treatment system for continuous fiber 3D printed components according to claim 6, characterized in that, The ultraviolet light assembly includes a heat sink plate disposed on the top surface of the work box and a lamp frame disposed on the top surface of the work box directly above the fixture. A PCB board is disposed on the bottom surface of the heat sink plate, and a number of LED beads are arranged in a rectangular array on the bottom surface of the PCB board. Each LED bead is placed inside the lamp frame, and a convex lens is disposed at the bottom end of the lamp frame corresponding to each LED bead. The number of convex lenses are integrally formed in an array.

9. The surface treatment system for continuous fiber 3D printed components according to claim 8, characterized in that, The heat sink includes an integrally formed heat-conducting plate and several heat sinks. The heat sinks are arranged in a straight line at equal intervals on the top surface of the heat-conducting plate. A cooling fan is also provided on the top surface of the heat sinks for heat dissipation of the LED beads.

10. The surface treatment system for continuous fiber 3D printed components according to claim 9, characterized in that, It also includes a conical cylinder located on the top surface of the rotating seat directly below the fixture, and an annular collection box placed on the bottom surface of the work box below the drive motor. The top surface of the conical cylinder has a horn-shaped opening, and arc-shaped guide pipes are fixedly connected to the symmetrical side walls of the conical cylinder. The output end of the arc-shaped guide pipes faces the annular collection box and is used to collect the dripping light-curing resin.

Images