A dual-mode rotating magnetization field generating device for assisting DLP 3D printing and a 3D printing method

Abstract

The application provides a dual-mode rotating magnetization field generating device for assisting DLP 3D printing and a 3D printing method, and relates to the technical field of 3D printing. The existing magnet field generating device based on a permanent magnet has the problems of simple structure, single magnet field and difficulty in realizing directional alignment of multidirectional and two-dimensional materials. The device comprises two oppositely arranged rotating magnet field generating device units, each of which comprises a rotating magnet field device, a rotating plane adjusting device and a support seat. The power output end of the stepping motor of the rotating plane adjusting device is connected to the input end of the driving mechanism, which is used to drive the directional adjusting gear and the driving rod to rotate, and further drive the rotating magnet field device to rotate around the axis of the driving rod. The rotating magnet field device comprises a fixed frame body, a servo motor, a driving component and a permanent magnet on the fixed frame body. The power output end of the servo motor is sequentially connected to the driving component and the permanent magnet, which is used to drive the permanent magnet to rotate in the fixed frame body.

Description

Technical Field

[0001] This invention relates to the field of 3D printing technology, and more specifically, to a dual-mode rotating magnetization field generating device and a 3D printing method for assisting DLP 3D printing. Background Technology

[0002] 3D printing technology is a relatively new manufacturing technology that has emerged in recent decades. Its advantages lie in its ability to create integrated molding and manufacture complex structures. Currently, the most widely used 3D printing technologies on the market include mature solutions such as photopolymerization (DLP, LCD, and SLA, etc.), material extrusion (FDM and DIW, etc.), and laser thermoforming (SLS, DED, etc.). Among them, DLP technology based on photopolymerization has advantages such as low equipment cost, long service life, low material cost, and simple preparation, and has been widely used in scientific research, biomedicine, and personalized customization.

[0003] However, traditional photosensitive resin materials used in DLP 3D printing often fail to meet the performance requirements of structural components in special applications. For example, components such as tires, brake pads, and clutch discs require resin materials with excellent friction resistance and mechanical properties. Therefore, further exploration of solutions to enhance resin material performance is needed. In recent years, multiphysics-assisted 3D printing technology has gradually emerged and developed. It fully utilizes the physicochemical properties of the printed material, selecting appropriate physical fields to act on the reinforcing phase, allowing the reinforcing phase to be controllably distributed in the resin, ultimately resulting in composite material components with enhanced performance. Among these, magnetic field-assisted 3D printing technology has gradually found practical applications, such as in flexible robots, improving the mechanical properties of composite materials, and strengthening medical microneedles. Magnetic field-assisted 3D printing technology can align magnetic or magnetized non-magnetic particles in a certain direction, thereby enhancing the mechanical or magnetic properties of the composite material in that direction. Currently, while electromagnet solutions can achieve arbitrary alignment of magnetic or magnetized non-magnetic particles, their complex structure, expensive equipment, and difficulty in large-scale production hinder their adoption. More importantly, their low magnetic field strength cannot achieve magnetic enhancement of the material. While permanent magnet-based magnetic field generating devices possess high magnetic field strength, their simple structure and unidirectional magnetic field make it difficult to achieve multi-directional and two-dimensional material alignment. Therefore, there is an urgent need to research a novel permanent magnet-assisted device to enhance the magnetic properties of 3D printed prototypes. Summary of the Invention

[0004] The technical problem to be solved by this invention is:

[0005] Existing magnetic field generating devices based on permanent magnets have simple structures and single magnetic fields, making it difficult to achieve directional alignment of materials in multiple directions and two dimensions.

[0006] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0007] This invention provides a dual-mode rotating magnetization field generating device for assisting DLP 3D printing. The dual-mode rotating magnetization field generating device includes two rotating magnetic field generating device units arranged opposite to each other. Each rotating magnetic field generating device unit includes a rotating magnetic field device, a rotating plane adjustment device, and a support base.

[0008] The support base includes a first support plate, a second support plate, and a fixed base plate. The first support plate and the second support plate are installed on both sides of the upper end face of the fixed base plate.

[0009] The rotating plane adjustment device includes a direction adjustment gear, a drive rod, and a stepper motor. One end of the drive rod passes through a support plate and is fixedly connected to the rotating magnetic field device. The other end of the drive rod is connected to a support plate. The direction adjustment gear is located between the support plate and the support plate and is coaxially fixedly connected to the drive rod. The steering stepper motor is mounted on the upper surface of the fixed base plate. The power output end of the steering stepper motor is connected to the input end of the drive mechanism. The drive mechanism is used to drive the direction adjustment gear and the drive rod to rotate, and further drive the rotating magnetic field device to rotate around the axis of the drive rod.

[0010] The rotating magnetic field device includes: a fixed frame and a servo motor, a drive component, and a permanent magnet on the fixed frame. The power output end of the servo motor is connected to the drive component and the permanent magnet in sequence. The drive component is used to drive the permanent magnet to rotate within the fixed frame. The fixed frame is fixedly connected to the drive rod.

[0011] Furthermore, the rotating plane adjustment device also includes a synchronizing rod, the two ends of which are fixedly connected to the direction adjustment gear and the fixed frame, respectively.

[0012] Furthermore, the stepper motor drives the direction adjustment gear to rotate within an angle range of 0-180°.

[0013] Furthermore, the support plate is provided with a rotating groove, the opening of which faces the same direction as the rotation direction of the drive rod, and the rotating groove is adapted to the rotation trajectory of the synchronizing rod.

[0014] Furthermore, one end of the drive rod extends to the outer end of the second support plate, is fixed by a bearing, and is connected to an angle display device to display the rotation angle of the drive rod.

[0015] Furthermore, the permanent magnet is a vertically mounted cylindrical permanent magnet with radial magnetization. The servo motor rotates through the drive component, further driving the permanent magnet to rotate around the axial direction.

[0016] Furthermore, the distance between the two permanent magnets arranged opposite each other is 60-300mm.

[0017] Furthermore, the servo motor speed is not less than 100 rpm.

[0018] Furthermore, the method for determining the minimum speed of the servo motor is as follows: The method for determining the minimum speed of the servo motor (2) is as follows: Based on the force conditions of the disc-shaped magnetic particles in the liquid resin, without considering the gravitational torque T g The effect of considering the viscous torque T under steady rotational conditions. η With magnetic torque T m In equilibrium, i.e., T η +T m =0, substituting formulas (1) and (2) into the torque balance equation, and according to the phase lag formula (3), the critical speed threshold shown in formula (4) is obtained:

[0019]

[0020]

[0021]

[0022]

[0023] Where μ0 is the free permeability, χ ps η is the magnetic permeability of the magnetic filler, d is the thickness of the magnetic layer, η is the resin viscosity, H0 is the intensity of the rotating magnetic field, a is half the thickness of the magnetic disk particles, b is the radius of the magnetic disk particles, f and f0 are both Perrin friction coefficients, and φ is the magnetic permeability of the magnetic filler. p Let θ be the angle between the magnetic disk particle and the direction of gravity, θ be the angle between the magnetic field and the diameter direction of the magnetic disk particle, and ω be the rotational speed of the magnetic field. c The critical revolutions required for the magnetic field to align.

[0024] A printing method using the dual-mode rotating magnetization field generator described in any of the above technical solutions includes the following steps:

[0025] Step 1: Prepare magnetic resin material and store the prepared resin material in a dark environment away from light for later use;

[0026] Step 2: Adjust the distance between the rotating magnetic field generating units at both ends of the resin tank to determine the magnetic field strength, set the servo motor rotation speed and adjust the stepper motor drive angle; place the resin material in the resin tank, and before starting the actual printing, turn on the servo motor to generate a rotating magnetic field at the preset rotation speed to pre-magnetize and align the magnetic particles, and turn on the steering stepper motor to rotate the magnetic plane to the specified angle through the direction adjustment gear at the preset drive angle.

[0027] Step 3: Import the 3D printing model file into the slicing software and set the printing parameters; the DLP light source projects patterned light onto the bottom of the resin tank, runs the printing device, and cures the magnetic resin material to obtain a magnetically enhanced composite material print.

[0028] Compared with the prior art, the beneficial effects of the present invention are:

[0029] This invention discloses a dual-mode rotating magnetization field generating device and a 3D printing method for assisting DLP 3D printing. It employs a dual-configuration rotating magnetic field generating device, uses a permanent magnet as the magnetic source, obtains a rotating magnetic field through a servo motor, and adjusts the action surface of the rotating magnetic field through a steering stepper motor to achieve arbitrary alignment of magnetic particles, ultimately obtaining a magnetically enhanced composite material component.

[0030] The device of this invention has a simple structure, low maintenance and repair costs, and large upgrade potential, making it a promising application.

[0031] The device of this invention produces a high magnetic field strength, and the magnitude and direction of the magnetic field are easily adjustable, which can meet the requirements of liquid magnetic resins with different magnetic properties.

[0032] The device of this invention can be used with a wide range of magnetic material systems, including hard magnetic and soft magnetic material systems, and also has the ability to form complex structures and printing precision. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the rotating magnetization field generating device in an embodiment of the present invention;

[0034] Figure 2 This is a schematic diagram of the structure of the rotating magnetic field generating device unit with opposite orientation in an embodiment of the present invention;

[0035] Figure 3 This is a torque analysis diagram of the disc-shaped magnetic particles in liquid resin in an embodiment of the present invention;

[0036] Figure 4 This describes the magnetic field distribution state under a static magnetic field in an embodiment of the present invention.

[0037] Figure 5 This is a diagram showing the alignment state of magnetic particles under a static magnetic field in an embodiment of the present invention.

[0038] Figure 6 The diagram shows the magnetic field distribution when the rotation angles are 45° (left) and 90° (right) in the embodiments of the present invention.

[0039] Figure 7 The images show the magnetic characterization results of different printed parts in the embodiments of the present invention.

[0040] Explanation of reference numerals in the attached figures:

[0041] 1-Support plate one, 2-Servo motor, 3-Drive component, 4-Fixed plate one, 5-Permanent magnet, 6-Fixed plate two, 7-Fixed side plate, 8-Direction adjustment gear, 9-Drive rod, 10-Bearing mounting seat, 11-Support plate two, 12-Fixed base plate, 13-Steering stepper motor, 14-Steering gear, 15-Synchronizer rod, 16-Slider base, 17-Slider, 18-Lead screw, 19-Drive motor, 20-Fixed flange. Detailed Implementation

[0042] In the description of this invention, it should be noted that the terms used in the various embodiments, such as "upper," "lower," "front," "rear," "left," and "right," which indicate orientation, are only used to simplify the description of the positional relationships based on the accompanying drawings and do not mean that the components and devices referred to must be operated in accordance with the specific orientations and defined operations, methods, and structures in the specification. Such directional terms do not constitute a limitation of this invention.

[0043] In the description of this invention, it should be noted that the terms "first," "second," and "third" mentioned in the embodiments of this invention are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first," "second," and "third" may explicitly or implicitly include one or more of that feature.

[0044] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0045] Specific Implementation Plan 1: (e.g.) Figure 1 and Figure 2 As shown, the present invention provides a dual-mode rotating magnetization field generating device for assisting DLP 3D printing. The dual-mode rotating magnetization field generating device includes two rotating magnetic field generating device units arranged opposite to each other. Each rotating magnetic field generating device unit includes a rotating magnetic field device, a rotating plane adjustment device, and a support base.

[0046] The support base includes a first support plate 1, a second support plate 11, and a fixed base plate 12. The first support plate 1 and the second support plate 11 are installed on both sides of the upper end face of the fixed base plate 12.

[0047] The rotating plane adjustment device includes a direction adjustment gear 8, a drive rod 9, and a stepper motor 13. One end of the drive rod 9 passes through the support plate 1 and is fixedly connected to the rotating magnetic field device. The other end of the drive rod 9 is connected to the support plate 11. The direction adjustment gear 8 is located between the support plate 1 and the support plate 11 and is coaxially fixedly connected to the drive rod 9. The steering stepper motor 13 is mounted on the upper surface of the fixed base plate 12. The power output end of the steering stepper motor 13 is connected to the input end of the drive mechanism. The drive mechanism adopts a steering gear 14. The drive mechanism is used to drive the direction adjustment gear 8 and the drive rod 9 to rotate, and further drive the rotating magnetic field device to rotate around the axis of the drive rod 9.

[0048] The rotating magnetic field device includes: a fixed frame and a servo motor 2, a drive component and a permanent magnet 5 on the fixed frame. The power output end of the servo motor 2 is connected to the drive component 3 and the permanent magnet 5 in sequence. The drive component 3 is used to drive the permanent magnet 5 to rotate within the fixed frame. The fixed frame is fixedly connected to the drive rod 9.

[0049] In this embodiment, the fixed frame includes a first fixed plate 4, a second fixed plate 6, two side plates, and a bottom plate. The first fixed plate 4, the second fixed plate 6, and the two side plates are respectively installed opposite each other on the side end face of the bottom plate. The other end face of the bottom plate is connected to the drive rod 9. The first fixed plate 4 and the second fixed plate 6 are respectively set at the lower end and the upper end of the permanent magnet 5. The two side plates are respectively set at the two sides of the permanent magnet 5. The drive component 3 adopts a flange. The two sides of the flange are fixedly connected to the two side plates. The upper end of the flange passes through the first fixed plate 4 and is connected to the bottom end of the permanent magnet 5. The flange is driven by the servo motor 2 to further drive the permanent magnet 5 to rotate.

[0050] In this embodiment, two rotating magnetic field generating units are installed opposite each other on both sides of the resin tank. By adjusting the servo motor 2 and the steering stepper motor 13, the rotation of the magnetic field and the adjustment of the magnetic field action surface are completed. The rotating magnetic field will drive the magnetic particles (such as carbonyl iron powder, iron tetroxide and neodymium iron boron particles, etc.) to rotate. When the rotation frequency is greater than the critical value, the rotation speed of the magnetic particles cannot keep up with the speed of the rotating magnetic field and remains stationary. Finally, the particles are aligned in the rotation plane and then printed.

[0051] In this embodiment, the structural supports and fixing components are all made of weakly magnetic materials such as aluminum alloy.

[0052] The dual-mode rotating magnetization field generator in this embodiment can produce a unidirectional and relatively uniform magnetic field.

[0053] Specific Implementation Scheme Two: The rotating plane adjustment device further includes a synchronizing rod 15, the two ends of which are fixedly connected to the direction adjusting gear 8 and the fixed frame, respectively. This implementation scheme is otherwise the same as Specific Implementation Scheme One.

[0054] Specific Implementation Scheme 3: The stepper motor 13 drives the direction adjustment gear 8 to rotate within an angle range of 0-180°. All other aspects of this implementation scheme are the same as Specific Implementation Scheme 2.

[0055] Specific Implementation Scheme Four: The support plate 1 has a rotating groove, the opening of which faces the same direction as the rotation of the drive rod, and the rotating groove is adapted to the rotation trajectory of the synchronizing rod 15. This implementation scheme is otherwise the same as Specific Implementation Scheme Three.

[0056] Specific Implementation Scheme 5: One end of the drive rod 9 extends to the outer end of the support plate 2 11, is fixed by a bearing, and is connected to an angle display device to display the rotation angle of the drive rod 9. This implementation scheme is otherwise the same as Specific Implementation Scheme 1.

[0057] Specific Implementation Scheme Six: The permanent magnet 5 is a vertically mounted cylindrical permanent magnet, magnetized radially. The servo motor 2 rotates via the drive component 3, further driving the permanent magnet 5 to rotate around its axial direction. All other aspects of this implementation scheme are the same as in Specific Implementation Scheme One.

[0058] In this implementation scheme, the permanent magnets are NdFeB magnets, N52 grade, with a remanence of 1.43T; the magnetic pole directions of the two permanent magnets 5 are NSNS.

[0059] Specific Implementation Plan Seven: (e.g.) Figure 2 As shown, the dual-mode rotating magnetization field generator also includes a slide rail module. Two opposing rotating magnetic field generator units are mounted on the slide rail module, and the distance between the two rotating magnetic field generator units can be adjusted along the slide rail module to adjust the magnetic field strength. The distance between the two permanent magnets 5 is 60-300mm. Other aspects of this embodiment are the same as in specific embodiment one.

[0060] In this embodiment, the slide rail module includes a slider base 16, a slider 17, a lead screw 18, a drive motor 19, and a fixed flange 20. Both of the rotating magnetic field generating device units are connected to the slider base 16 via the slider 17. The lead screw 18 is a positive and negative threaded lead screw, located above the slider base 16, and connected to the sliders 17 of the two rotating magnetic field generating device units via positive and negative threads, respectively. The drive motor 19 is located at the end of the dual-mode rotating magnetization field generating device, and the output end of the drive motor 19 is connected to the lead screw 18 via the fixed flange 20, which is used to drive the lead screw 18 to rotate axially, thereby causing the two rotating magnetic field generating device units on the lead screw 18 to move closer to or further away from each other.

[0061] Specific Implementation Scheme Eight: The rotational speed of servo motor 2 is not less than 100 rpm. All other aspects of this scheme are the same as Specific Implementation Scheme One.

[0062] Specific implementation plan nine: The method for determining the minimum speed of servo motor 2 is as follows: Figure 3 As shown, the disc-shaped magnetic particles in the liquid resin will be subjected to a gravitational torque T. g Viscous torque T η and magnetic torque T m Function, of which T g Relative to T m The difference is more than two orders of magnitude smaller, therefore T is not considered. g The function of T. m and T η The calculation formulas are shown in formulas (1) and (2), considering the viscous torque T under steady rotation. η With magnetic torque T m In equilibrium, i.e., T η +T m =0, substituting formulas (1) and (2) into the torque balance equation, and according to the phase lag formula (3), the critical speed threshold shown in formula (4) is obtained:

[0063]

[0064]

[0065]

[0066]

[0067] Where μ0 is the free permeability, χ ps η is the magnetic permeability of the magnetic filler, d is the thickness of the magnetic layer, η is the resin viscosity, H0 is the intensity of the rotating magnetic field, a is half the thickness of the magnetic disk particles, b is the radius of the magnetic disk particles, f and f0 are both Perrin friction coefficients, and φ is the magnetic permeability of the magnetic filler. p Let θ be the angle between the magnetic disk particle and the direction of gravity, θ be the angle between the magnetic field and the diameter direction of the magnetic disk particle, and ω be the rotational speed of the magnetic field. c The critical revolutions required for magnetic field alignment. This implementation scheme is otherwise identical to specific implementation scheme eight.

[0068] Specific Implementation Scheme Ten: A printing method using the dual-mode rotating magnetization field generator described in the above implementation scheme, comprising the following steps:

[0069] Step 1: Preparation of magnetic resin material: Mix 20 parts by weight of carbonyl iron powder and 72 parts by weight of photosensitive resin monomer 4-hydroxybutyl acrylate. Then, add 2 parts by weight of BYK 163 as a dispersant, 2 parts by weight of nano-fumed silica as a rheology modifier, and 4 parts by weight of 6900-20X as an anti-precipitant. Mix and stir for 1 hour to obtain magnetic photosensitive resin. Store the prepared resin material in a dark environment away from light for later use.

[0070] Step 2: Adjust the distance between the rotating magnetic field generating units at both ends of the resin tank to determine the magnetic field strength, set the rotation speed of the servo motor 2 and adjust the drive angle of the stepper motor 13; place the resin material in the resin tank, and before starting the formal printing, turn on the servo motor 2 to generate a rotating magnetic field at the preset rotation speed to pre-magnetize and align the magnetic particles, and turn on the steering stepper motor 13 to rotate the magnetic plane to the specified angle through the direction adjustment gear 8 at the preset drive angle.

[0071] Step 3: Import the 3D printing model file into the slicing software and set the printing parameters; the DLP light source projects patterned light onto the bottom of the resin tank, which is a transparent plate. When the printing device is running, the light passes through the bottom of the resin tank to cure the photosensitive resin material, resulting in a magnetically enhanced composite material print.

[0072] The printed part was placed in a beaker containing alcohol and ultrasonically cleaned for 5 minutes, followed by magnetic characterization. The test results are as follows. Figure 7 As shown, it demonstrates that magnetically reinforced composite materials can be manufactured by selecting the magnetic field-assisted DLP 3D printing process.

[0073] A dual-mode rotating magnetization field generator for assisting DLP 3D printing has been tested and proven to manufacture magnetically enhanced composite materials. This invention does not affect the printing accuracy or complex structure forming capability of the DLP 3D printing process, achieving a minimum printing resolution better than 170µm, which is sufficient for most applications. It provides a new process approach for manufacturing composite materials with enhanced properties and has significant practical application value.

[0074] The dual-mode rotating magnetization field generator for DLP 3D printing of this invention can achieve multiple working modes; static magnetic field working mode: neither the servo motor 2 nor the steering stepper motor 13 works, and only the distance between the rotating magnetic field generator unit and the resin tank needs to be adjusted according to the material response characteristics, such as... Figure 4 and Figure 5As shown, the magnetic particles are aligned along the direction of the static magnetic field. After alignment, the magnetic particles are distributed in a linear pattern in the liquid resin, which enhances the material properties in that direction. Then, during printing, the distribution of the magnetic particles is ensured to remain unaffected by the vertical movement of the printing substrate. Dynamic magnetic field working mode: First, two servo motors 2 rotate synchronously, driving the cylindrical permanent magnet 5 to rotate and generate a rotating magnetic field. Then, the steering stepper motor 13 drives the direction adjustment gear 8 to rotate by a specified angle, adjusting the plane of action of the rotating magnetic field. This allows the magnetic particles to be aligned in different magnetic planes. Finally, printing is performed, as shown... Figure 6 As shown, during the printing process, the angle can be adjusted as needed via a steering stepper motor to generate rotating magnetic fields in different planes. Single / Dual Module Working Mode: A single or dual rotating magnetic field generator unit can be selected to operate according to actual needs. Dual rotating magnetic field generator units can form a dual magnetic field, which has advantages in orientation, intensity, and magnetic field uniformity compared to a single rotating magnetic field generator unit. The operating mode of a single rotating magnetic field generator unit is completely consistent with that of two rotating magnetic field generator units.

[0075] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A dual-mode rotating magnetization field generating device for assisting DLP 3D printing, characterized in that, The dual-mode rotating magnetization field generator includes two opposing rotating magnetic field generator units, each of which includes a rotating magnetic field device, a rotating plane adjustment device, and a support base; The support base includes a support plate one (1), a support plate two (11) and a fixed base plate (12), and the support plate one (1) and the support plate two (11) are installed on both sides of the upper end face of the fixed base plate (12); The rotating plane adjustment device includes a direction adjustment gear (8), a drive rod (9), and a steering stepper motor (13). One end of the drive rod (9) passes through the first support plate (1) and is fixedly connected to the rotating magnetic field device. The other end of the drive rod (9) is connected to the second support plate (11). The direction adjustment gear (8) is located between the first support plate (1) and the second support plate (11) and is coaxially fixedly connected to the drive rod (9). The steering stepper motor (13) is installed on the upper surface of the fixed base plate (12). The power output end of the steering stepper motor (13) is connected to the input end of the drive mechanism. The drive mechanism is used to drive the direction adjustment gear (8) and the drive rod (9) to rotate, and further drive the rotating magnetic field device to rotate around the axis of the drive rod (9). The rotating magnetic field device includes: a fixed frame and a servo motor (2), a drive component (3) and a permanent magnet (5) on the fixed frame. The power output end of the servo motor (2) is connected to the drive component (3) and the permanent magnet (5) in sequence. The drive component (3) is used to drive the permanent magnet (5) to rotate in the fixed frame. The fixed frame is fixedly connected to the drive rod (9). The permanent magnet (5) is a vertically mounted cylindrical permanent magnet with radial magnetization. The servo motor (2) rotates through the drive component (3), which further drives the permanent magnet (5) to rotate around its axis.

2. The dual-mode rotating magnetization field generating device for assisting DLP 3D printing according to claim 1, characterized in that, The rotating plane adjustment device also includes a synchronizing rod (15), the two ends of which are fixedly connected to the direction adjustment gear (8) and the fixed frame, respectively.

3. The dual-mode rotating magnetization field generating device for assisting DLP 3D printing according to claim 2, characterized in that, The steering stepper motor (13) drives the direction adjustment gear (8) to rotate within an angle range of 0-180°.

4. The dual-mode rotating magnetization field generating device for assisting DLP 3D printing according to claim 3, characterized in that, The support plate (1) has a rotating groove that is adapted to the rotation trajectory of the synchronizing rod (15).

5. The dual-mode rotating magnetization field generating device for assisting DLP 3D printing according to claim 3, characterized in that, One end of the drive rod (9) extends to the outer end of the support plate (11), is fixed by a bearing, and is connected to an angle display device to display the rotation angle of the drive rod (9).

6. The dual-mode rotating magnetization field generating device for assisting DLP 3D printing according to claim 1, characterized in that, The distance between the two permanent magnets (5) set opposite to each other is 60-300 mm.

7. The dual-mode rotating magnetization field generating device for assisting DLP 3D printing according to claim 1, characterized in that, The rotational speed of the servo motor (2) is not less than 100 revolutions per minute.

8. The dual-mode rotating magnetization field generating device for assisting DLP 3D printing according to claim 7, characterized in that, The method for determining the minimum speed of the servo motor (2) is as follows: based on the force situation of the disc-shaped magnetic particles in the liquid resin, without considering the gravitational torque T. g The effect of considering the viscous torque T under steady rotational conditions. η With magnetic torque T m In equilibrium, i.e., T η +T m =0, substitute formulas (1) and (2) into the torque balance equation, and according to the phase lag formula (3), obtain the critical speed threshold as shown in formula (4): （1） （2） （3） （4） in, The permeability of free space, Let d be the magnetic permeability of the magnetic particles, and d be the thickness of the magnetic layer. Let be the resin viscosity, H0 be the rotating magnetic field strength, a be half the thickness of the magnetic disk particle, b be the radius of the magnetic disk particle, and f and f0 be the Perrin friction coefficients. The angle between the magnetic disk particle and the direction of gravity is denoted as . The angle between the magnetic field and the diameter direction of the magnetic disk particle. The rotational speed of the magnetic field. The critical revolutions required for the magnetic field to align.

9. A printing method using the dual-mode rotating magnetization field generating device according to any one of claims 1 to 8, characterized in that, Includes the following steps: Step 1: Prepare magnetic resin material and store the prepared resin material in a dark environment away from light for later use; Step 2: Adjust the distance between the rotating magnetic field generating units at both ends of the resin tank to determine the magnetic field strength, set the rotation speed of the servo motor (2) and adjust the driving angle of the steering stepper motor (13); place the resin material in the resin tank, and before starting the formal printing, turn on the servo motor (2) to generate a rotating magnetic field at the preset rotation speed to pre-magnetize and align the magnetic particles, and turn on the steering stepper motor (13) to rotate the magnetic plane to the specified angle through the direction adjustment gear (8) at the preset driving angle. Step 3: Import the 3D printing model file into the slicing software and set the printing parameters; The DLP light source projects patterned light onto the bottom of the resin tank, runs the printing device, and cures the magnetic resin material to obtain a magnetically enhanced composite material print.

Images