Fiber pre-tightening device for 3D printing continuous fiber composite material

Abstract

The invention discloses a fiber pre-tightening device for a 3D printing continuous fiber composite material, and relates to the technical field of 3D printing. Pre-tightening tension of continuous fibers is applied through the pre-tightening roller assembly and matched with anti-skid lines to enhance grabbing force, a tension sensor in the yarn guide pipe mechanism monitors fiber tension changes in real time, the control unit dynamically adjusts the displacement amount of a hydraulic cylinder based on feedback signals, and accurate closed-loop control over the fiber tension is achieved; the detachable design (such as a connecting shaft, a positioning frame and a fastener) is adopted, so that parts can be conveniently and quickly replaced, and different fiber types and diameter requirements are met; in addition, stable supporting and integrated management of the base ensure stable operation of the whole device, tension fluctuation caused by vibration or deviation is avoided, and therefore the uniform tension of fibers is maintained in the 3D printing process, and the forming quality and efficiency of the composite material are improved.

Description

Technical Field

[0001] This invention relates to the field of 3D printing technology, and more specifically to a fiber pre-tightening device for 3D printing continuous fiber composite materials. Background Technology

[0002] 3D printing, also known as additive manufacturing or layer-by-layer manufacturing, is a technology that uses digital model files as a basis and employs powdered metals or plastics and other bondable materials to construct objects layer by layer. 3D printing is commonly used in mold making and industrial design to create models, and is increasingly being used for the direct manufacturing of some products. It has profoundly impacted traditional processes, production lines, factory models, and supply chain structures, making it a representative disruptive technology in the manufacturing industry.

[0003] In 3D printing methods, fused deposition modeling can print continuous fiber resin-based composite materials through in-situ impregnation. However, continuous fibers are prone to tangling due to feed resistance when encountering corners and arcs, resulting in uneven fiber distribution in the material during printing. This also makes it easy for difficult corner or arc printing to fail or for the dimensions to be unqualified. To address this, we propose a fiber pre-tightening device for 3D printing continuous fiber composite materials. Summary of the Invention

[0004] The purpose of this invention is to provide a fiber pre-tightening device for 3D printing continuous fiber composite materials in order to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention specifically adopts the following technical solution:

[0006] A fiber pretensioning device for 3D printing continuous fiber composite materials includes:

[0007] A pre-tensioning roller assembly includes a main roller body. Positioning frames are detachably connected to both ends of the main roller body via connecting shafts. An adjusting plate is movably connected to the interior of each positioning frame via a limiting shaft. The lower ends of two adjusting plates are connected via a limiting shaft. Limiting plates are movably connected to both ends of the limiting shaft. Adjusting cylinders are fitted onto the circumferential surfaces of both ends of the limiting shaft. A hydraulic cylinder is installed at the lower end of each adjusting cylinder. A base is installed at the lower ends of the limiting plates and the hydraulic cylinders.

[0008] The guide wire mechanism includes multiple support frames evenly arranged in a horizontal direction. Each support frame has a tension sensor installed inside its bottom wall. Each support frame has an adjusting shaft movably installed inside its interior. The circumferential surface of the adjusting shaft is fitted with a guide wheel. Both ends of each adjusting shaft extend to the outside of the support frame, and fasteners are detachably installed on the circumferential surface of the extension.

[0009] A control unit is located on the front side of the pretension roller assembly, and the control unit is connected to the tension sensor and the hydraulic cylinder in the pretension roller assembly for dynamically adjusting the tension;

[0010] The base is located below the preload roller assembly and the wire guide tube mechanism.

[0011] Furthermore, each of the positioning frames has a through groove at its lower end, and the upper end of the adjusting plate is installed in the through groove.

[0012] Furthermore, the two ends of the limiting shaft extend to the outside of the positioning frame, and the circumferential surface of the extension is fitted with a positioning element. The circumferential surface of the two ends of the limiting shaft is provided with external threads, and the positioning element is provided with internal threads. The limiting shaft and the positioning element are connected by threads.

[0013] Furthermore, a limiting groove is provided at the lower end of the adjustment plate located on the rear side, and the lower end of the adjustment plate located on the front side is installed in the limiting groove.

[0014] Furthermore, the limiting plate has a movable groove with arc-shaped ends inside, and the limiting shaft is movably connected to the limiting plate through the movable groove.

[0015] Furthermore, the support frame has an internal movable groove with arc-shaped ends, and the adjusting shaft is movably connected to the support frame through the movable groove.

[0016] Furthermore, each of the two ends of the adjusting shaft is provided with a threaded connection portion, and the fastener is provided with an internal thread. The adjusting shaft and the fastener are connected by the thread.

[0017] Furthermore, the control unit includes:

[0018] The feedback mechanism automatically triggers an alarm or shutdown function when the tension value exceeds the preset threshold to prevent fiber breakage or loosening. The preset threshold is set in the range of 5 to 50 Newtons, and the specific value is dynamically adjusted according to the fiber type and diameter.

[0019] The audible and visual alarm uses an audible and visual alarm device to provide real-time alerts to operators.

[0020] The stopping mechanism is linked to the wire feeding motor via an electromagnetic clutch;

[0021] The data logging module is used to store historical tension values ​​and alarm events.

[0022] Furthermore, the control unit integrates a user interface module, allowing the operator to set tension parameters and monitor the operating status.

[0023] Furthermore, a recessed groove is provided above the base, and the lower ends of the base and the support frame are inserted into the recessed groove.

[0024] The beneficial effects of this invention are as follows:

[0025] 1. This invention applies pretension to continuous fibers through a pretension roller assembly and enhances gripping force with anti-slip texture. The tension sensor in the guide tube mechanism monitors fiber tension changes in real time, and the control unit dynamically adjusts the displacement of the hydraulic cylinder based on the feedback signal to achieve precise closed-loop control of fiber tension.

[0026] 2. The present invention adopts a detachable design (such as connecting shaft, positioning frame and fasteners) to facilitate quick replacement of parts and adapt to different fiber types and diameter requirements; in addition, the stable support and integrated management of the base ensure the stable operation of the entire device and avoid tension fluctuations caused by vibration or displacement, thereby maintaining uniform fiber tension during the 3D printing process and improving the quality and efficiency of composite material molding. Attached Figure Description

[0027] Figure 1 This is a three-dimensional schematic diagram of the present invention;

[0028] Figure 2 This is a front sectional view of the present invention;

[0029] Figure 3 This is a three-dimensional schematic diagram of the pre-tightening roller assembly in this invention;

[0030] Figure 4 This is a three-dimensional schematic diagram of the positional relationship between the guide wire mechanism and the tension sensor in this invention;

[0031] Figure 5 This is a block diagram of the control unit in this invention.

[0032] Reference numerals in the attached drawings: 1. Pretension roller assembly; 11. Main roller body; 12. Connecting shaft; 13. Positioning frame; 14. Limiting shaft; 15. Adjusting plate; 16. Limiting shaft; 17. Limiting plate; 18. Adjusting cylinder; 19. Hydraulic cylinder; 110. Base; 2. Guide tube mechanism; 21. Support frame; 22. Adjusting shaft; 23. Guide wheel; 24. Fastener; 3. Tension sensor; 4. Control unit; 5. Base. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0034] Please see Figure 1 - Figure 5 The present invention provides a fiber pretensioning device for 3D printing continuous fiber composite materials, comprising:

[0035] The pretensioning roller assembly 1 includes a main roller body 11. Positioning frames 13 are detachably connected to both ends of the main roller body 11 via connecting shafts 12. Each positioning frame 13 has an adjusting plate 15 movably connected to its interior via a limiting shaft 14. The lower ends of two adjusting plates 15 are connected via a limiting shaft 16, and limiting plates 17 are movably connected to both ends of the limiting shaft 16. Adjusting cylinders 18 are fitted onto the circumferential surfaces of both ends of the limiting shaft 16. A hydraulic cylinder 19 is mounted at the lower end of each adjusting cylinder 18. A base 110 is mounted at the lower ends of the limiting plates 17 and the hydraulic cylinders 19. The main roller body 11 is used to apply pretension to the continuous fibers, and its surface is provided with anti-slip textures to enhance fiber gripping force. The device enables quick disassembly and replacement through the cooperation of the connecting shaft 12 and the positioning frame 13. At the same time, the rotational movement of the main roller 11, in conjunction with the synergistic action of the adjusting plate 15 and the hydraulic cylinder 19, precisely controls the pre-tension of the fiber, ensuring that the fiber maintains uniform tension during the 3D printing process and avoiding slippage or loosening. The hydraulic cylinder 19 provides precise hydraulic adjustment force, driving the adjusting cylinder 18 and the limiting shaft 16 to move up and down, thereby driving the adjusting plate 15 to adjust the height of the main roller 11 and the usage requirements of main rollers 11 of different lengths, realizing real-time dynamic control of fiber tension. In addition, the device also includes a fiber guiding mechanism to guide continuous fibers smoothly into the pre-tensioning roller assembly 1, avoiding fiber twisting or breakage.

[0036] The fiber guide tube mechanism 2 includes multiple support frames 21 evenly arranged in the horizontal direction. Each support frame 21 has a tension sensor 3 installed inside its bottom wall, and an adjusting shaft 22 movably installed inside each support frame 21. A guide wheel 23 is fitted onto the circumferential surface of the adjusting shaft 22. Both ends of each adjusting shaft 22 extend to the outside of the support frame 21, and fasteners 24 are detachably installed on the circumferential surface of the extension. The support frames 21 are used to fix and support the adjusting shafts 22, ensuring stable rotation of the guide wheels 23 during fiber guidance and preventing fiber twisting or breakage. Simultaneously, the tension sensor 3 installed inside the bottom wall of the support frame 21 monitors changes in fiber tension in real time and feeds the data back to the control unit 4, coordinating with the hydraulic cylinder 19 to adjust the pre-tightening force, achieving precise closed-loop control of fiber tension. Furthermore, the support frames 21 allow for quick replacement of the adjusting shafts 22 and guide wheels 23 via detachable fasteners 24, adapting to different fiber diameters or wear requirements, thus improving the flexibility and durability of the device.

[0037] The control unit 4 is located on the front side of the pretension roller assembly 1 and is connected to the tension sensor 3 and the hydraulic cylinder 19 in the pretension roller assembly 1. It is used to dynamically adjust the tension. Based on the fiber tension signal collected in real time by the tension sensor 3, the control unit 4 analyzes the signal through an algorithm and outputs control commands to the hydraulic cylinder 19 to drive the adjusting cylinder 18 to move up and down, thereby dynamically adjusting the height position of the pretension roller assembly 1 to ensure that the fiber maintains a constant pretension force during the conveying process.

[0038] The base 5 is located below the pretension roller assembly 1 and the wire guide tube mechanism 2. The base 5 is used to provide stable support and horizontal positioning for the entire device. Adjustable anchor bolts are provided at the bottom of the base 5 to facilitate precise leveling during equipment installation. The base 5 has a pre-set hydraulic pipeline channel and cable groove, which are respectively connected to the hydraulic cylinder 19 of the pretension roller assembly 1 and the tension sensor 3 of the wire guide tube mechanism 2 to the control unit 4, so as to realize integrated management of power transmission and signal feedback.

[0039] In this embodiment, preferably, each positioning frame 13 has a through groove at its lower end, and the upper end of the adjusting plate 15 is installed in the through groove. By setting the through groove and the limiting shaft 14, the angle between the upper end of the adjusting plate 15 and the positioning frame 13 can be adjusted.

[0040] In this embodiment, preferably, both ends of the limiting shaft 14 extend to the outside of the positioning frame 13, and a positioning element is sleeved on the circumferential surface of the extension. The circumferential surfaces at both ends of the limiting shaft 14 are provided with external threads, and the positioning element is provided with internal threads. The limiting shaft 14 and the positioning element are connected by threads. This arrangement ensures the positional stability of the adjusting plate 15 after angle adjustment.

[0041] In this embodiment, preferably, the lower end of the rear adjusting plate 15 is provided with a limiting groove, and the lower end of the front adjusting plate 15 is installed in the limiting groove. Under the action of the limiting groove, it can be ensured that the two adjusting plates 15 maintain a synchronous movement trajectory under the linkage action of the limiting shaft 16, and prevent the mechanism from jamming due to unilateral offset.

[0042] In this embodiment, preferably, the limiting plate 17 has a movable groove with arc-shaped ends inside, and the limiting shaft 16 is movably connected to the limiting plate 17 through the movable groove. The movable groove allows the limiting shaft 16 to move smoothly in the vertical direction, adapting to the height adjustment requirements of the main roller 11, while reducing frictional resistance and stress concentration, and improving the durability and motion accuracy of the mechanism.

[0043] In this embodiment, preferably, the support frame 21 has an internal movable groove with arc-shaped ends, and the adjusting shaft 22 is movably connected to the support frame 21 through the movable groove. The movable groove allows the adjusting shaft 22 to move smoothly in the vertical direction, adapting to the adjustment requirements of the guide rollers 23 at different heights, while reducing frictional resistance and stress concentration, improving the durability and motion accuracy of the mechanism; in addition, the arc-shaped structure design of the movable groove ensures the stability of the adjusting shaft 22 during movement, preventing deviation caused by unilateral force, thereby ensuring uniform tension of the fiber during the guiding process and avoiding twisting or breakage.

[0044] In this embodiment, preferably, each adjusting shaft 22 has a threaded connection on its circumferential surface at both ends, and the fastener 24 has an internal thread. The adjusting shaft 22 and the fastener 24 are connected by the thread. The threaded connection allows for quick locking or loosening of the adjusting shaft 22, ensuring that the guide wheel 23 maintains a stable position during fiber guidance, preventing axial displacement caused by vibration or force, and simplifying the maintenance and replacement process of the guide wheel 23.

[0045] In this embodiment, preferably, the control unit 4 includes:

[0046] The feedback mechanism automatically triggers an alarm or shutdown function when the tension value exceeds the preset threshold to prevent fiber breakage or loosening. The preset threshold is set in the range of 5 to 50 Newtons, and the specific value is dynamically adjusted according to the fiber type and diameter.

[0047] The audible and visual alarm uses an audible and visual alarm device to provide real-time alerts to operators.

[0048] The stopping mechanism is linked to the wire feeding motor via an electromagnetic clutch;

[0049] The data logging module is used to store historical tension values ​​and alarm events.

[0050] With the coordinated operation of the aforementioned components, the control unit 4 can achieve intelligent closed-loop control of fiber tension. By receiving feedback signals from the tension sensor 3 in the guide tube mechanism 2 in real time, and combining them with a preset algorithm to dynamically calculate the displacement of the hydraulic cylinder 19, it precisely drives the adjusting cylinder 18 to move up and down, thereby adaptively adjusting the height position of the pre-tightening roller assembly 1 to ensure that the fiber maintains a constant pre-tightening force throughout the conveying process. At the same time, the feedback mechanism triggers an audible and visual alarm when the tension value exceeds the threshold, and cuts off the power supply to the fiber feeding motor through the shutdown mechanism, effectively preventing fiber breakage or loosening accidents. The data recording module automatically stores operating parameters and alarm events, facilitating subsequent process optimization and fault tracing.

[0051] In this embodiment, preferably, the control unit 4 integrates a user interface module, allowing the operator to set tension parameters and monitor the operating status, thereby improving the automation level and reliability of the device.

[0052] In this embodiment, preferably, a recess is provided above the base 5, and the lower ends of the base 110 and the support frame 21 are inserted into the recess. The recess ensures the installation stability of the base 110 and the support frame 21 and facilitates replacement and maintenance.

[0053] Working principle and usage process of this invention: When using this device,

[0054] The operator first sets the fiber tension parameters (preset threshold range of 5 to 50 Newtons, dynamically adjusted according to fiber type and diameter) through the user interface module of the control unit 4, and then starts the fiber feeding mechanism. Continuous fibers smoothly enter the pretension roller assembly 1 from the fiber inlet mechanism. The main roller 11 grips the fibers through its surface anti-slip texture, applying initial pretension. The hydraulic cylinder 19 drives the adjusting cylinder 18 to move up and down based on the fiber tension signal fed back in real time by the tension sensor 3. This drives the limiting shaft 16 and the adjusting plate 15 to coordinately adjust the height position of the main roller 11, achieving precise closed-loop control of fiber tension. This ensures that a uniform pretension is maintained throughout the 3D printing process, preventing slippage or loosening.

[0055] The guide rollers 23 of the guide tube mechanism 2 guide the fibers to move stably under the support of the adjusting shaft 22. The movable groove design of the support frame 21 allows for vertical displacement adjustment to adapt to different fiber path requirements and prevent twisting or breakage. When the tension value exceeds the preset threshold, the feedback mechanism of the control unit 4 immediately triggers the audible and visual alarm to issue a warning, and cuts off the power supply to the fiber feeding motor through the electromagnetic clutch linked by the shutdown mechanism to prevent fiber breakage accidents. At the same time, the data recording module automatically stores the operating parameters and alarm events, which is convenient for subsequent process optimization.

[0056] During use, the stable support of the base 5 and the integrated pipeline ensure efficient and reliable hydraulic power and signal transmission. The operator can monitor the tension status and system operation data in real time through the user interface. After use, the positioning frame 13 or guide wheel 23 can be easily disassembled for maintenance and replacement.

[0057] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A 3D printing continuous fiber composite material fiber pre-tightening device, characterized in that, include: A pre-tightening roller assembly (1) includes a main roller body (11). The two ends of the main roller body (11) are detachably connected to positioning frames (13) via connecting shafts (12). Each positioning frame (13) has an adjusting plate (15) movably connected to its interior via a limiting shaft (14). The lower ends of the two adjusting plates (15) are connected via a limiting shaft (16). The two ends of the limiting shaft (16) are movably connected to limiting plates (17). Adjusting cylinders (18) are sleeved on the circumferential surfaces of both ends of the limiting shaft (16). A hydraulic cylinder (19) is installed at the lower end of each adjusting cylinder (18). A base (110) is installed at the lower ends of the limiting plates (17) and the hydraulic cylinders (19). The guide wire mechanism (2) includes multiple support frames (21) evenly arranged in the horizontal direction. Each support frame (21) has a tension sensor (3) installed inside the bottom wall. Each support frame (21) has an adjusting shaft (22) movably installed inside. The circumferential surface of the adjusting shaft (22) is fitted with a guide wheel (23). Both ends of each adjusting shaft (22) extend to the outside of the support frame (21), and fasteners (24) are detachably installed on the circumferential surface of the extension. A control unit (4) is located on the front side of the pretension roller assembly (1), and the control unit (4) is connected to the tension sensor (3) and the hydraulic cylinder (19) in the pretension roller assembly (1) for dynamically adjusting the tension; The base (5) is located below the pre-tightening roller assembly (1) and the wire guide tube mechanism (2).

2. The 3D printing continuous fiber composite material fiber pre-tightening device according to claim 1, characterized in that, Each of the positioning frames (13) has a through groove at its lower end, and the upper end of the adjusting plate (15) is installed in the through groove.

3. The fiber pre-tightening device for 3D printing continuous fiber composite materials according to claim 1, characterized in that, The two ends of the limiting shaft (14) extend to the outside of the positioning frame (13), and the circumferential surface of the extension is fitted with a positioning member. The circumferential surface of the two ends of the limiting shaft (14) is provided with external threads, and the positioning member is provided with internal threads. The limiting shaft (14) and the positioning member are connected by threads.

4. The 3D printing continuous fiber composite material fiber pre-tightening device according to claim 1, characterized in that, The lower end of the adjustment plate (15) located on the rear side is provided with a limiting groove, and the lower end of the adjustment plate (15) located on the front side is installed in the limiting groove.

5. The 3D printing continuous fiber composite material fiber pre-tightening device according to claim 1, characterized in that, The limiting plate (17) has a movable groove with arc-shaped ends inside, and the limiting shaft (16) is movably connected to the limiting plate (17) through the movable groove.

6. The 3D printing continuous fiber composite material fiber pre-tightening device according to claim 1, characterized in that, The support frame (21) has a movable groove with arc-shaped ends inside, and the adjusting shaft (22) is movably connected to the support frame (21) through the movable groove.

7. The 3D printing continuous fiber composite material fiber pre-tightening device according to claim 1, characterized in that, Each of the two ends of the adjusting shaft (22) is provided with a threaded connection part, and the fastener (24) is provided with an internal thread. The adjusting shaft (22) and the fastener (24) are connected by the thread.

8. The 3D printing continuous fiber composite material fiber pre-tightening device according to claim 1, characterized in that, The control unit (4) includes: The feedback mechanism automatically triggers an alarm or shutdown function when the tension value exceeds the preset threshold to prevent fiber breakage or loosening. The preset threshold is set in the range of 5 to 50 Newtons, and the specific value is dynamically adjusted according to the fiber type and diameter. The audible and visual alarm uses an audible and visual alarm device to provide real-time alerts to operators. The stopping mechanism is linked to the wire feeding motor via an electromagnetic clutch; The data logging module is used to store historical tension values ​​and alarm events.

9. The 3D printing continuous fiber composite material fiber pre-tightening device according to claim 1, characterized in that, The control unit (4) integrates a user interface module, which allows the operator to set tension parameters and monitor the operating status.

10. The 3D printing continuous fiber composite material fiber pre-tightening device according to claim 1, characterized in that, A recessed groove is provided above the base (5), and the lower ends of the base (110) and the support frame (21) are inserted into the recessed groove.

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