A portable magnetic manipulation system and manipulation method applied to additive manufacturing

Abstract

The application provides a portable magnetic control system and control method applied to additive manufacturing, which comprises a magnetic field generating base, the magnetic field generating base has a containing cavity, and the magnetic field generating base is internally provided with an operation platform, a Z-axis electromagnetic coil, an X-axis electromagnetic coil and a Y-axis electromagnetic coil, wherein the operation platform is arranged in the containing cavity, an operation piece is placed on the operation platform, the Z-axis electromagnetic coil is arranged in the containing cavity and is arranged below the operation platform, the two X-axis electromagnetic coils are arranged in the containing cavity and are oppositely arranged with the operation platform as the center, and the two Y-axis electromagnetic coils are arranged in the containing cavity and are oppositely arranged with the operation platform as the center. The control system has portability, universality and the ability to generate various magnetic fields, can be easily integrated into various 3D printing devices, and the control method can flexibly and efficiently generate the required magnetic field according to the specific requirements of the 3D printing device, so that the flexibility and efficiency of the magnetic field control are realized.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing auxiliary technology, and in particular to a portable magnetic control system and control method for additive manufacturing. Background Technology

[0002] With the development of technology, functional magnetic materials have shown broad application prospects in many fields, especially in magnetically driven microrobots and flexible magnetic devices. However, the further application of these functional magnetic materials largely depends on the ability to manufacture structures with special geometries and magnetization properties. Traditional manufacturing technologies have limitations in handling complex geometries and internal structures, while additive manufacturing (3D printing) technology effectively solves this problem by virtue of its ability to accurately mold complex shapes and internal structures based on computer models. Against this backdrop, magnetic field-assisted 3D printing technology has emerged innovatively. This technology achieves precise control of the distribution of magnetic particles during the printing process by integrating a magnetic manipulation system. The core of magnetic field-assisted 3D printing technology lies in combining the high-precision layer-by-layer building capability of 3D printing with the magnetic field control of the magnetic manipulation system. This combination not only retains the advantages of 3D printing in building complex shapes but also endows the printed parts with unique magnetic properties, making them infinitely possible in fields such as microrobots, biomedicine, and electronic engineering. As the core component of magnetic field-assisted 3D printing technology, the magnetic manipulation system has the ability to generate and control a magnetic field in a certain direction, guiding the magnetic particles in the printing material to arrange themselves in an orderly manner according to a preset direction, thereby constructing a structure with a specific magnetization distribution.

[0003] However, most current magnetic field-assisted 3D printing technologies integrate the magnetic control system directly into specific printing equipment. This not only increases the overall complexity of the system, but also limits the versatility and adaptability of the magnetic control system across different operating platforms. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a portable magnetic manipulation system and method for additive manufacturing. The manipulation system is portable, versatile, and capable of generating various magnetic fields, making it easy to integrate into various 3D printing devices. Furthermore, the manipulation method can flexibly and efficiently generate the required magnetic field according to the specific needs of the 3D printed device, thereby achieving flexibility and efficiency in magnetic field manipulation. This significantly improves the controllability of magnetic fields in magnetic field-assisted 3D printing and can also play a beneficial role in multiple fields such as magnetic material manipulation, biomedicine, and microfluidics.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] A portable magnetic manipulation system for additive manufacturing, comprising:

[0007] A magnetic field generating base is provided, the base having a receiving cavity, and an operating platform, a Z-axis electromagnetic coil, an X-axis electromagnetic coil, and a Y-axis electromagnetic coil are disposed within the base.

[0008] The operating platform is located in the receiving cavity, and operating components are placed on the operating platform;

[0009] The Z-axis electromagnetic coil is disposed in the receiving cavity and located below the operating platform. The Z-axis electromagnetic coil extends along a first direction to generate a magnetic field in the first direction.

[0010] The two X-axis electromagnetic coils are disposed within the receiving cavity and are arranged opposite each other with the operating platform as the center, and the two X-axis electromagnetic coils extend along the second direction to generate a magnetic field in the second direction;

[0011] The two Y-axis electromagnetic coils are disposed within the cavity and are positioned opposite each other with the operating platform as the center. The two Y-axis electromagnetic coils extend along a third direction to generate a magnetic field in the third direction. The second direction intersects with the third direction, and the first direction intersects with the plane formed by the second direction and the third direction.

[0012] Furthermore, it also includes a magnetic field generating cover, the operating platform is disposed at the bottom of the magnetic field generating cover, the magnetic field generating cover and the magnetic field generating base are detachably connected so that the operating platform can be selectively disposed in the receiving cavity, and both the magnetic field generating cover and the magnetic field generating base are provided with multiple heat dissipation holes.

[0013] Furthermore, the receiving cavity is provided with multiple snap-fit ​​structures, each of which is used to snap-fit ​​with a Y-axis electromagnetic coil or an X-axis electromagnetic coil.

[0014] Furthermore, it also includes a control unit, which comprises a power supply, a driver, a controller, and a host computer. The power supply and the driver are electrically connected to the controller, and the controller is electrically connected to the host computer. The power supply is used to provide power. The driver includes an X-axis electromagnetic coil driver, a Y-axis electromagnetic coil driver, and a Z-axis electromagnetic coil driver. The Z-axis electromagnetic coil driver is electrically connected to the Z-axis electromagnetic coil to drive and generate a magnetic field in the Z direction. The X-axis electromagnetic coil driver is electrically connected to two X-axis electromagnetic coils to drive and generate a magnetic field in the X direction. The Y-axis electromagnetic coil driver is electrically connected to two Y-axis electromagnetic coils. The magnetic coils are electrically connected to drive the generation of a magnetic field in the Y direction. The two X-axis electromagnetic coils are connected in parallel or in series, and the two Y-axis electromagnetic coils are connected in parallel or in series. The controller reads the magnetic field parameters from the host computer and compiles the magnetic field parameters into a PWM wave control signal that can be received by the X-axis electromagnetic coil driver, the Y-axis electromagnetic coil driver, and / or the Z-axis electromagnetic coil driver. The X-axis electromagnetic coil driver, the Y-axis electromagnetic coil driver, and / or the Z-axis electromagnetic coil control the power supply output current according to the PWM wave control signal to control the Z-axis electromagnetic coil, the two X-axis electromagnetic coils, and / or the two Y-axis electromagnetic coils to generate a magnetic field.

[0015] Furthermore, the magnetic field generating base is detachably fixed in the 3D printing system or magnetic field manipulation device, wherein the 3D printing system is a photopolymerization 3D printing system or a material extrusion 3D printing system.

[0016] A portable magnetic manipulation method for additive manufacturing, applied to the aforementioned portable magnetic manipulation system for additive manufacturing, includes the following steps:

[0017] Set the required magnetic field, which can be a magnetic field of a certain direction and magnitude, a spatial rotating magnetic field, or a conical spiral magnetic field;

[0018] Control the Z-axis electromagnetic coil, two X-axis electromagnetic coils, and / or two Y-axis electromagnetic coils to generate the required magnetic field.

[0019] Furthermore, when the required magnetic field is a magnetic field of a certain direction and magnitude, the input currents are as follows:

[0020]

[0021] Among them, I X I Y I Z The currents input to the X-axis electromagnetic coil, Y-axis electromagnetic coil, and Z-axis electromagnetic coil are respectively under a magnetic field of a certain direction and magnitude. α1, α2, and β are all linear relationship coefficients, p0 is the pitch angle under a magnetic field of a certain direction and magnitude, and d0 is the direction angle under a magnetic field of a certain direction and magnitude.

[0022] Furthermore, when the required magnetic field is a spatial rotating magnetic field, the input currents are as follows:

[0023]

[0024] Among them, I X′ I Y′ I Z′ p0′ represents the current input to the X-axis electromagnetic coil, Y-axis electromagnetic coil, and Z-axis electromagnetic coil under the spatial rotating magnetic field, f is the frequency, and t is the time.

[0025] Furthermore, when the required magnetic field is a planar rotating magnetic field, the input currents along the X and Y axes are respectively:

[0026]

[0027] Among them, I X′ I Y′ The input currents to the X-axis and Y-axis electromagnetic coils under the planar rotating magnetic field are α1 and α2, which are linear relationship coefficients, f is the frequency, and t is the time.

[0028] The current input to the Z-axis electromagnetic coil under the spatial rotating magnetic field is 0.

[0029] Furthermore, when the required magnetic field is a conical spiral magnetic field, the currents along the X and Y axes gradually decrease while the current along the Z axis gradually increases.

[0030] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0031] (1) Traditional magnetic field control systems used to assist 3D printing are mostly integrated with the printing system, which increases the overall complexity of the equipment and also weakens the versatility of the magnetic field control system. The design of a portable magnetic control system can solve this problem well. The whole system can be used in material extrusion 3D printing scenarios and also in photopolymerization 3D printing scenarios, and has good portability.

[0032] (2) The Z-axis electromagnetic coil, two X-axis electromagnetic coils and two Y-axis electromagnetic coils are arranged in a right-handed manner, which can generate a variety of special magnetic fields that are not available in traditional magnetic field manipulation systems, such as regional approximate gradient magnetic fields, rotating magnetic fields, and conical spiral magnetic fields, thus solving the problem that traditional magnetic manipulation systems used to assist 3D printing generate relatively simple magnetic field types.

[0033] (3) The circular printing platform in the center of the heat dissipation cover is sunken, so that it can be simultaneously acted on by the Z-axis electromagnetic coil, two X-axis electromagnetic coils and two Y-axis electromagnetic coils. Because it is close enough to the coils, the magnetic field strength is sufficient to control the magnetic particles, which solves the problem that the magnetic manipulation system used to assist 3D printing generates a weak magnetic field.

[0034] (4) The overall system design concept is replicable, the control logic is simple, it has high plasticity, and it can be flexibly adjusted to cope with changing environments and needs. Attached Figure Description

[0035] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and are intended to explain the invention, but do not constitute an undue limitation thereof. In the drawings:

[0036] Figure 1 This is a schematic diagram showing the structure of the magnetic field generating base and the magnetic field generating cover of the present invention, which are separated.

[0037] Figure 2 This is an exploded view of the portable magnetic control system of the present invention;

[0038] Figure 3 This is a schematic diagram of the overall structure of the portable magnetic control system of the present invention;

[0039] Figure 4 This is a schematic diagram of the portable magnetic control system of the present invention applied to a material extrusion 3D printing system;

[0040] Figure 5 This is a schematic diagram of the portable magnetic control system of the present invention applied to a photopolymerization 3D printing system;

[0041] Figure 6 This is an overall schematic diagram of the connection between the portable magnetic control system and the control unit of the present invention;

[0042] Figure 7 This is a schematic diagram of the control strategy of the portable magnetic control system of the present invention;

[0043] Figure 8 This is a wiring diagram of the portable magnetic control system and driver of the present invention;

[0044] Figure 9 This is a schematic diagram of a magnetic field of a certain direction and a certain magnitude for the portable magnetic control system of the present invention.

[0045] Figure 10 This is a diagram showing the relationship between the uniaxial magnetic field and current at the center of the circular printing platform of the portable magnetic control system of the present invention.

[0046] Figure 11This is a schematic diagram of the gradient magnetic field generated by the portable magnetic control system of the present invention.

[0047] Figure 12 A schematic diagram illustrating the generation of a rotating magnetic field by the portable magnetic control system of this invention;

[0048] Figure 13 This is a schematic diagram illustrating the analysis of a printed sample produced by the portable magnetic manipulation system of this invention.

[0049] Among them, 100, magnetic control system; 1, magnetic field generating base; 101, receiving cavity; 2, operating platform; 3, Z-axis electromagnetic coil; 4, X-axis electromagnetic coil; 5, Y-axis electromagnetic coil; 6, magnetic field generating cover; 7, snap-fit ​​structure; 8, heat dissipation holes; 9, reinforcing ribs; 10, ring; 11, plastic screw; 12, power supply; 13, driver; 14, controller; 15, small magnetic needle; 16, circular mesh printed sample; 17, magnetic particles inside the printed sample; 200, material extrusion 3D printing system; 300, photopolymerization 3D printing system. Detailed Implementation

[0050] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0051] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0052] Example 1

[0053] In existing magnetic field-assisted 3D printing systems, the magnetic control components sometimes use simple magnets as the magnetic field source, but cannot precisely control the direction of the magnetic field; other systems integrate complex magnetic field devices with the printing equipment, which achieves precise control of the magnetic field, but increases the overall system complexity and limits the versatility of the portable magnetic control system 100 in different printing systems.

[0054] To address the aforementioned problems, this invention innovatively proposes a portable magnetic manipulation system 100—P-MagDisk—for additive manufacturing. This portable magnetic manipulation system 100 is characterized by its high portability, versatility, and ability to generate various magnetic fields. It can be easily integrated into various 3D printing equipment, achieving flexibility and efficiency in magnetic field manipulation. Through its designed electromagnetic coil portable magnetic manipulation system 100 and magnetic field manipulation algorithm, P-MagDisk can generate the required magnetic field according to the needs of the printed device. Whether generating gradient magnetic fields or rotating magnetic fields, P-MagDisk can achieve both.

[0055] This embodiment provides a portable magnetic control system 100 for additive manufacturing, which can be divided into hardware modules and software modules, such as... Figures 1-3 As shown, the hardware module includes a magnetic field generating base 1, which has a receiving cavity 101. The magnetic field generating base 1 is equipped with an operating platform 2, a Z-axis electromagnetic coil 3, an X-axis electromagnetic coil 4, and a Y-axis electromagnetic coil 5.

[0056] The operating platform 2 is located in the receiving cavity 101, and the operating components are placed on the operating platform 2.

[0057] The Z-axis electromagnetic coil 3 is disposed in the receiving cavity 101 and below the operating platform 2. The Z-axis electromagnetic coil 3 extends along the first direction to generate a magnetic field in the first direction.

[0058] Two X-axis electromagnetic coils 4 are disposed within the receiving cavity 101 and are arranged opposite each other with the operating platform 2 as the center, and the two X-axis electromagnetic coils 4 extend along the second direction to generate a magnetic field in the second direction.

[0059] Two Y-axis electromagnetic coils 5 are disposed in the receiving cavity 101 and are arranged opposite each other with the operating platform 2 as the center. The two Y-axis electromagnetic coils 5 extend along a third direction to generate a magnetic field in the third direction. The second direction and the third direction intersect, and the first direction intersects with the plane formed by the second direction and the third direction.

[0060] This embodiment controls the Z-axis electromagnetic coil 3, two X-axis electromagnetic coils 4 and / or two Y-axis electromagnetic coils 5 to generate the required magnetic field by setting the required magnetic field, so as to control the operating part and realize the 3D printing of the operating part or the magnetic control of the operating part.

[0061] In this embodiment, for the electromagnetic coils, it is first clarified that a single electromagnetic coil can only generate a magnetic field in one direction. To generate a magnetic field in any direction, the arrangement of the electromagnetic coils needs to be designed. The portable magnetic manipulation system 100 used in additive manufacturing, in order to generate a magnetic field in any desired direction during printing, arranges the electromagnetic coils according to a right-handed coordinate system, where the X and Y axes each consist of two electromagnetic coils, and the Z axis has one electromagnetic coil. Since the controlled object of the portable magnetic manipulation system 100 used in additive manufacturing is the magnetic particles inside the magnetic material, the magnetic force generated by the output magnetic field of this portable magnetic manipulation system 100 only needs to overcome the interaction force between the particles, and the magnetic field strength is only on the order of mT. In this embodiment, when a 10A current is applied, the portable magnetic manipulation system 100 used in additive manufacturing can generate a maximum magnetic field of 18mT along the X or Y direction at the intersection of the normals of the five electromagnetic coils (i.e., the center of the operating platform 2), and a maximum magnetic field of 54mT along the Z direction. This magnetic field strength is sufficient to control and rearrange the magnetic particles inside the material.

[0062] In this embodiment, as Figures 1-3 As shown, the magnetic field generating base 1 has a rectangular cavity structure. To facilitate carrying and installation of this portable magnetic control system 100, a magnetic field generating cover 6 is also included. The magnetic field generating cover 6 has a rectangular plate structure, and the operating platform 2 is located below the magnetic field generating cover 6. Considering that the operation of the electromagnetic coils affects the surrounding magnetic materials, commercially available plastic screws 11 are used to detachably connect the magnetic field generating base 1 and the magnetic field generating cover 6, allowing the operating platform 2 to be selectively placed in the receiving cavity 101. The receiving cavity 101 needs to accommodate five electromagnetic coils, thus requiring a certain strength from the magnetic field generating base 1. To increase the strength of the magnetic field generating base 1, reinforcing ribs 9 are arranged around the receiving cavity 101 to strengthen the connection between the bottom and sides of the magnetic field generating base 1, further improving the strength and rigidity of the magnetic field generating base 1. In the portable magnetic manipulation system 100 used in additive manufacturing, the main function of the magnetic field generating base 1 is to provide stable support for the electromagnetic coil and a suitable working platform for 3D printing. The magnetic field generating base 1 is mainly made of white resin material. Considering that the electromagnetic coil generates a lot of heat during operation, heat dissipation holes 8 of different sizes are provided on the magnetic field generating base 1. The magnetic field generating cover 6 also has multiple heat dissipation holes 8 of different sizes.

[0063] In this embodiment, a fixing member is also included. The top of the fixing member is fixed to the magnetic field generating cover 6, and the bottom of the fixing member is fixed to the operating platform 2, so that the operating platform 2 is positioned below the magnetic field generating cover 6. In a specific embodiment, the fixing member is a cylinder. The top of the fixing member is welded to or integrally connected to the magnetic field generating cover 6, and the bottom of the fixing member is welded to or integrally connected to the operating platform 2.

[0064] When the magnetic field generating cover 6 and the magnetic field generating base 1 are fixed, and the operating platform 2 is located in the receiving cavity 101, when the magnetic field generating cover 6 and the magnetic field generating base 1 are disassembled and separated, the Z-axis electromagnetic coil 3, X-axis electromagnetic coil 4 and Y-axis electromagnetic coil 5 in the receiving cavity 101 can be adjusted.

[0065] In this embodiment, to balance heat dissipation and support stability, a snap-fit ​​structure 7 is used to engage with the Z-axis electromagnetic coil 3 or the X-axis electromagnetic coil 4 to provide support and sufficient heat dissipation space for the Y-axis electromagnetic coil 5 or the X-axis electromagnetic coil 4. Specifically, in this embodiment, the snap-fit ​​structure 7 consists of two V-shaped blocks spaced at a certain distance. The bottom of the V-shaped blocks is fixed to the receiving cavity 101, providing support and sufficient heat dissipation space for the X-axis electromagnetic coil 4 and the Y-axis electromagnetic coil 5. Since the central Z-axis electromagnetic coil 3 is small, a ring 10 supplemented with plastic screws 11 is used to clamp and fix the Z-axis electromagnetic coil 3. Furthermore, to serve the 3D printing system and target millimeter-micron level printing applications, the operating platform 2 and the magnetic field generating cover 6 are not on the same horizontal plane. Instead, the operating platform 2 is sunken a certain distance relative to the magnetic field generating cover 6, making it parallel to the central axes of the X-axis electromagnetic coil 4 and the Y-axis electromagnetic coil 5. The diameter of the operating platform 2 is 70–100 mm. This arrangement allows the printing material within the operating platform 2 to be better affected by the five electromagnetic coils. The magnetic field generating cover 6 and the magnetic field generating base 1 are similar to a "lid" and a "box". The installation of the whole structure can be completed simply by placing the magnetic field generating cover 6 on the magnetic field generating base 1 according to the orientation.

[0066] In this specific embodiment, the operating platform 2 has a diameter of approximately 80 mm. Since devices manufactured using magnetic field-assisted 3D printing technology are generally at the millimeter or micrometer level, the 80 mm operating platform 2 provided by the portable magnetic manipulation system 100 for additive manufacturing is sufficient to meet diverse printing needs.

[0067] In this embodiment, as Figures 6-8As shown, it also includes a control unit, which includes a power supply 12, a driver 13, a controller 14, and a host computer. The power supply 12 and driver 13 are both electrically connected to the controller 14, and the controller 14 is electrically connected to the host computer. The power supply 12 provides power. The driver 13 includes an X-axis electromagnetic coil driver, a Y-axis electromagnetic coil driver, and a Z-axis electromagnetic coil driver. The Z-axis electromagnetic coil driver is electrically connected to a Z-axis electromagnetic coil 3 to generate a magnetic field in the Z direction. The X-axis electromagnetic coil driver is electrically connected to two X-axis electromagnetic coils 4 to generate a magnetic field in the X direction. The Y-axis electromagnetic coil driver is electrically connected to two Y-axis electromagnetic coils 4. Coil 5 is electrically connected to drive the generation of a magnetic field in the Y direction. Two X-axis electromagnetic coils 4 are connected in parallel or in series, and two Y-axis electromagnetic coils 5 are connected in parallel or in series. The controller reads the magnetic field parameters from the host computer and compiles the magnetic field parameters into PWM wave control signals that can be received by the X-axis electromagnetic coil driver, Y-axis electromagnetic coil driver and / or Z-axis electromagnetic coil driver. The X-axis electromagnetic coil driver and / or Y-axis electromagnetic coil driver and Z-axis electromagnetic coil driver control the power supply output current according to the PWM wave control signal to control the Z-axis electromagnetic coil 3, the two X-axis electromagnetic coils 4 and / or the two Y-axis electromagnetic coils 5 to generate a magnetic field.

[0068] Specifically, the power supply is a CSP-3000 power supply, and the driver is a CoPley driver. The CSP-3000 power supply mainly powers the CoPley driver. The myRIO controller reads the magnetic field parameters from the host computer software, compiles the magnetic field parameters into a PWM wave control signal that the driver can receive, and sends the control signal to the CoPley driver through the control bus. The driver then controls the power supply output current to control the electromagnetic coil according to the control signal.

[0069] The software component of the portable magnetic control system 100 used in additive manufacturing mainly includes the magnetic field control algorithm, the LabVIEW control interface (host computer program), and the COMSOL magnetic field simulation model. According to the Biot-Savart law, the magnetic field generated by an electromagnetic coil at a certain point is directly proportional to the current. Therefore, controlling the magnetic field at a point only requires controlling the current input to the electromagnetic coil. The magnetic field control algorithm is based on this principle. It calculates the corresponding current using the input magnetic field parameters and converts this current signal into PWM wave signals with different duty cycles, which are then sent. This is the logic of the magnetic field control algorithm. The LabVIEW control interface, as the host computer program, allows input of the required magnetic field parameters, setting of the myRIO controller's wiring ports, and compilation and execution of the magnetic field control code. The COMSOL magnetic field simulation model can realistically reflect the magnitude and direction of the magnetic field generated by the portable magnetic control system 100 used in additive manufacturing. Combined with the magnetic field control program, it allows for optimization of the magnetic field control code in a simulation environment.

[0070] like Figure 4 and Figure 5 As shown, the design of the portable magnetic control system 100 for additive manufacturing ensures its high convenience. In practical applications, the portable magnetic control system 100 can be placed in either a material extrusion 3D printing system 200 or a photopolymerization 3D printing system 300. The prerequisite for its application is adjusting the printing height of the 3D printing system. Due to its low height, the portable magnetic control system 100 can be accommodated by most 3D printing systems. Furthermore, the portable magnetic control system 100 can also function as a standalone magnetic field manipulation device, capable of controlling devices such as magnetic particles and small magnetic components. In conclusion, the portable magnetic control system 100 for additive manufacturing is a portable magnetic control system with significant application value and diverse application scenarios.

[0071] The magnetic field generating base 1 can be detachably fixed in a 3D printing system or magnetic field manipulation device. The 3D printing system is a photopolymerization 3D printing system 300 or a material extrusion 3D printing system 200.

[0072] In summary, this embodiment has the following advantages:

[0073] (1) Traditional magnetic field control systems used to assist 3D printing are mostly integrated with the printing system, which increases the overall complexity of the equipment and also weakens the versatility of the magnetic field control system. The design of the portable magnetic control system 100 can solve this problem well. The whole system can be used in material extrusion 3D printing scenarios and also in photopolymerization 3D printing scenarios, and has good portability.

[0074] (2) The Z-axis electromagnetic coil 3, two X-axis electromagnetic coils 4 and two Y-axis electromagnetic coils 5 are arranged in a right-handed manner, which can generate a variety of special magnetic fields that are not available in traditional magnetic field control systems, such as regional approximate gradient magnetic fields, rotating magnetic fields, and conical spiral magnetic fields, thus solving the problem that the traditional portable magnetic control system 100 used to assist 3D printing generates a relatively simple type of magnetic field.

[0075] (3) The circular printing platform in the center of the heat dissipation cover is sunken, so that it can be simultaneously acted on by the Z-axis electromagnetic coil 3, two X-axis electromagnetic coils 4 and two Y-axis electromagnetic coils 5. Because it is close enough to the coils, the magnetic field strength is sufficient to control the magnetic particles, which solves the problem that the traditional portable magnetic manipulation system 100 used to assist 3D printing generates a weak magnetic field.

[0076] (4) The design concept of the overall portable magnetic control system 100 is replicable, the control logic is simple, it has high plasticity, and it can be flexibly adjusted to cope with changing environments and needs.

[0077] Example 2

[0078] Example 2 provides a portable magnetic manipulation method for additive manufacturing, applied to the aforementioned portable magnetic manipulation system 100 for additive manufacturing, comprising the following steps:

[0079] Step S1: Set the required magnetic field, which can be a magnetic field of a certain direction and magnitude, a planar rotating magnetic field, a spatial rotating magnetic field, or a conical spiral magnetic field.

[0080] Step S2: Control the Z-axis electromagnetic coil 3, two X-axis electromagnetic coils 4 and / or two Y-axis electromagnetic coils 5 to generate the required magnetic field.

[0081] like Figure 9 The diagram illustrates a magnetic field of a specific direction and magnitude generated by the portable magnetic control system of this invention. When the required magnetic field is of a specific direction and magnitude, to generate such a magnetic field in the portable magnetic control system 100 used in additive manufacturing, the magnetic field generating element of the portable magnetic control system 100 consists of five combined electromagnetic coils. The X-axis electromagnetic coil 4 and the Y-axis electromagnetic coil 5 each have 340 turns. Two X-axis electromagnetic coils 4 and two Y-axis electromagnetic coils 5 are arranged on the X-axis and Y-axis respectively, resulting in an equivalent number of 680 turns for both the X-axis and Y-axis coils. The Z-axis coil has 485 turns. Since the magnetic field generated by the portable magnetic control system 100 is outside the coils, specifically in the operating platform 2, simulation results show that the magnetic field distribution on the operating platform 2 is non-uniform, with the weakest magnetic field at the center (center of the circle). This center will be referred to as the coil magnetic field operating point. For magnetron printing, an overly precise magnetic field is not required; a magnetic field greater than a certain threshold is sufficient (this threshold is determined by the properties of the magnetron 3D printing material). Therefore, if this threshold is 10 mT, as long as the magnetic field at the operating point of the coil is greater than 10 mT, the magnetic field on the entire operating platform 2 will also be greater than 10 mT, exceeding the threshold and thus satisfying the conditions for magnetron printing.

[0082] For a given point in space, the magnetic field has a linear relationship with the electric current, that is... Figure 7The formula showing the relationship between magnetic field and current is related to the number of coil turns and the distance from the coil center to the point. For the X and Y axes, the equivalent number of turns is 680, and the distance to the point is 39 mm. For the Z-axis, the distance from the coil center to the point is 8 mm, and the equivalent number of turns is 485. According to the Biot-Savart law, the magnetic field at a point has a linear relationship with the current, a linear relationship with the number of turns, and an inverse cubic relationship with the distance (r). Therefore, although the Z-axis coil has fewer turns, it is closer to the operating point of the coil, resulting in less magnetic field attenuation, and thus a larger magnetic field can be generated with the same current. The X and Y axis coils, being farther from the point, can only generate smaller magnetic fields with the same current.

[0083] Regarding the relationship between the magnetic field and current of a single-axis coil, the X, Y, and Z axis magnetic field components in this portable magnetic control system 100 are as follows:

[0084] B X =α1I X (1)

[0085] B Y =α2I Y (2)

[0086] B Z =βI Z (3)

[0087] Where α1, α2, and β are all linear relationship coefficients, I X I Y and I Z The input current is for the X-axis electromagnetic coil 4, Y-axis electromagnetic coil 5, and Z-axis electromagnetic coil 3.

[0088] When the distances from the X and Y axis coils to the coil operating point are the same and the equivalent number of turns is the same, the linear relationship coefficients of the X and Y axis magnetic field components are the same, α1=α2. However, the Z axis coil is different from the XY coil, and its coefficient is set to β.

[0089] Therefore, for the portable magnetic control system 100 to generate a magnetic field in any fixed direction, the specific magnetic field is represented as follows: Figure 11 To generate a composite magnetic field with a magnitude of A (mT), a direction angle of d0, and a pitch angle of p0 using the portable magnetic control system 100, the magnetic field components in the X, Y, and Z directions can be derived as follows:

[0090] B X =Acos(p0)sin(d0)(4)

[0091] B Y =Acos(p0)cos(d0)(5)

[0092] B Z=Asin(p0)(6)

[0093] Equating equations (4)-(6) with equations (1)-(3) respectively, we obtain the input currents for the X, Y, and Z axes as follows:

[0094]

[0095] Among them, I X I Y I Z The X-axis electromagnetic coil 4, Y-axis electromagnetic coil 5, and Z-axis electromagnetic coil 3 are respectively input into a magnetic field of a certain direction and magnitude. The linear relationship coefficients α1, α2, and β between the magnetic field and the current in the formula are obtained by magnetic field experiment calibration. These coefficients are related to the structure, number of turns, and other characteristics of the electromagnetic coils used. In the specific implementation of this embodiment, the parameters are measured, where α1 is 1.852, α2 is 1.852, and β is 5.425.

[0096] Therefore, in this specific embodiment, to generate a magnetic field with a magnitude of 10mT, a direction angle of 30°, and a pitch angle of 45°, the input triaxial current can be obtained as follows:

[0097]

[0098] Therefore, by simply controlling the driver to output the triaxial current as described above, the coil magnetic field operating point can generate a magnetic field with a magnitude of 10mT, a direction angle of 30°, and a pitch angle of 45° in a fixed direction.

[0099] When the required magnetic field is a spatial rotating magnetic field, the direction of the magnetic field changes. According to the Biot-Savart law, the current flowing through it should also change with time, meaning the current should be alternating current. Therefore, sin(2πft) and cos(2πft) are some parameters of the alternating current, where f is the frequency, representing the number of times the magnetic field changes in one second. In a spatial rotating magnetic field, the rotation period of the plane rotating magnetic field corresponding to the rotating plane and the pitch angle of the spatial rotating magnetic field relative to the rotating plane are mainly adjusted by adjusting this frequency parameter.

[0100]

[0101] Among them, I X′ I Y′ I Z′ p0′ represents the current input to the X-axis electromagnetic coil 4, Y-axis electromagnetic coil 5, and Z-axis electromagnetic coil 3 under the spatial rotating magnetic field, and p0′ represents the pitch angle under the spatial rotating magnetic field.

[0102] In this specific embodiment, if the pitch angle is 30°, then equations (10)-(12) change as follows:

[0103]

[0104] When the required magnetic field is a planar rotating magnetic field, since the magnetic field exists only in the XY plane, the Z-axis coil is not energized, and the pitch angle of the magnetic field is 0°. Furthermore, because the generated uniform planar rotating magnetic field has the same magnitude at any position at any given time, there is no concept of direction angle. In this case, the input triaxial current is:

[0105]

[0106] When the required magnetic field is a conical spiral magnetic field: as the current in the X-axis and Y-axis gradually decreases while the current in the Z-axis gradually increases, the pitch angle continues to increase, increasing from 0° to 90°. In this case, the magnetic field generated on the operating platform 2 is a conical spiral magnetic field.

[0107] The main characteristic of this magnetic field is its spiral progression; the magnetic field strength gradually increases and its direction gradually moves along the Z-axis. It is primarily used to disperse particles. Initially, the magnetic field is weak and the pitch angle is small, causing particles in the surrounding area to aggregate. Then, as the magnetic field strengthens and the pitch angle increases, the particles stand upright. At this point, two particles can be understood as two bar magnets, each with its N pole facing the Z-axis. The particles then experience a repulsive force, thus dispersing them. This demonstrates that this portable magnetic manipulation system 100 is not limited to assisting 3D printing; it can also be used as a magnetic manipulation device.

[0108] The control strategy of the overall portable magnetic control system 100 is as follows: Figure 6 The required magnetic field parameters are input into the LabVIEW control terminal, which is connected to the myRIO controller. The controller calculates the input parameters to obtain the coil current signal, and converts this current signal into PWM waves (control signals) with different duty cycles using a magnetic field algorithm. After compilation, the controller sends the signal to the CoPley driver via the control bus. The driver reads the control signal and adjusts the power supply output to generate the corresponding current, thereby controlling the portable magnetic manipulation system 100 to generate the required magnetic field. After completing this series of open-loop control, to further improve the accuracy of the magnetic field generated by the portable magnetic manipulation system 100, a three-dimensional magnetic sensor is used to measure the magnetic field parameters of the operating platform 2 and feeds them back to the LabVIEW control terminal, thereby further adjusting the current output. The three drivers used in this portable magnetic manipulation system 100 control the magnetic field components of the XYZ axes respectively. The wiring ports between the drivers and the controller are pre-configured. The interface connections of this portable magnetic manipulation system 100 are as follows: Figure 7 .

[0109] Figure 10The figure shows the relationship between the uniaxial magnetic field and the current at the center of the operating platform 2 of the portable magnetic control system 100. Since the portable magnetic control system 100 primarily serves a 3D printing system, the uniformity of the magnetic field is not a critical parameter, but the strength of the magnetic field does affect whether the required magnetic device can be printed. After the portable magnetic control system 100 is running, the magnetic field is weakest at the very center of the operating platform 2, meaning that the surrounding magnetic fields are all stronger than the magnetic field at the center. Therefore, it is only necessary to control the magnetic field strength at this point to reach the threshold that can drive the internal particles of the magnetic material to orient themselves, and the required magnetic device can be successfully printed. Controlling the magnetic field strength at this point requires obtaining the relationship between the magnetic field and the current at that point. The final relationship obtained experimentally is shown in the figure. The coefficients of this linear relationship are determined by the electromagnetic coil used; if the electromagnetic coil is replaced, these coefficients need to be measured again.

[0110] Figure 11 This diagram illustrates the generation of a regional gradient magnetic field by the portable magnetic control system 100. To visualize the magnetic field, small magnetic needles are evenly scattered in the operating platform 2. The portable magnetic control system 100 is then activated, generating a magnetic field at a 45-degree angle to the positive X-axis. Under the influence of this magnetic field, the small magnetic needles inside the operating platform 2 rotate accordingly. This example demonstrates that the portable magnetic control system 100 has the function of generating a magnetic field with a specific direction.

[0111] Figure 12 This diagram illustrates the generation of a rotating magnetic field in the XY plane for the portable magnetic manipulation system 100. Small magnetic needles are also scattered in the operating platform 2. The system is activated and set to generate a rotating magnetic field in the XY plane around the Z-axis. Under the influence of this rotating magnetic field, the small magnetic needles inside the operating platform 2 also rotate. However, since the magnetic field of this system is generated by an electromagnetic coil, the magnetic field within the operating platform 2 is not uniform. But for an assisted 3D printing system, this effect is almost negligible; the weak magnetic field gradient does not affect the overall magnetic particle distribution.

[0112] Figure 13 This example illustrates the analysis of a sample printed using a portable magnetic manipulation system 100 assisted by a material extrusion 3D printing system 200. Before printing, the portable magnetic manipulation system 100 generates a magnetic field along the Y direction, and then the 3D printer prints a circular mesh sample. After printing, the magnetic particles inside the printed sample are distributed along the Y direction. This application demonstrates that the portable magnetic manipulation system 100 can be well applied to 3D printing systems.

[0113] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A portable magnetic control device for additive manufacturing, characterized in that, Used to control and rearrange magnetic particles within a material, including: A magnetic field generating base is provided, the base having a receiving cavity, and an operating platform, a Z-axis electromagnetic coil, an X-axis electromagnetic coil, and a Y-axis electromagnetic coil are disposed within the base. The operating platform is located in the receiving cavity, and operating components are placed on the operating platform; The Z-axis electromagnetic coil is disposed in the receiving cavity and located below the operating platform. The Z-axis electromagnetic coil extends along a first direction to generate a magnetic field in the first direction. The two X-axis electromagnetic coils are disposed within the receiving cavity and are arranged opposite each other with the operating platform as the center, and the two X-axis electromagnetic coils extend along the second direction to generate a magnetic field in the second direction; The two Y-axis electromagnetic coils are disposed in the cavity and are arranged opposite each other with the operating platform as the center. The two Y-axis electromagnetic coils extend along a third direction to generate a magnetic field in the third direction. The second direction and the third direction intersect, and the first direction intersects with the plane formed by the second direction and the third direction. It also includes a magnetic field generating cover, the operating platform is disposed at the bottom of the magnetic field generating cover, and the magnetic field generating cover and the magnetic field generating base are detachably connected so that the operating platform can be selectively disposed in the receiving cavity; The operating platform is lowered relative to the magnetic field generating cover, and the operating platform is parallel to the central axis of the X-axis electromagnetic coil and the Y-axis electromagnetic coil.

2. The portable magnetic control device for additive manufacturing according to claim 1, characterized in that: Both the magnetic field generating cover and the magnetic field generating base have multiple heat dissipation holes.

3. The portable magnetic control device for additive manufacturing according to claim 1, characterized in that: The cavity is provided with multiple snap-fit ​​structures, each of which is used to snap-fit ​​with a Y-axis electromagnetic coil or an X-axis electromagnetic coil.

4. The portable magnetic control device for additive manufacturing according to claim 1, characterized in that: It also includes a control unit, which comprises a power supply, a driver, a controller, and a host computer. The power supply and the driver are electrically connected to the controller, and the controller is electrically connected to the host computer. The power supply provides power. The driver includes an X-axis electromagnetic coil driver, a Y-axis electromagnetic coil driver, and a Z-axis electromagnetic coil driver. The Z-axis electromagnetic coil driver is electrically connected to the Z-axis electromagnetic coil to generate a magnetic field in the Z direction. The X-axis electromagnetic coil driver is electrically connected to two X-axis electromagnetic coils to generate a magnetic field in the X direction. The Y-axis electromagnetic coil driver is electrically connected to two Y-axis electromagnetic coils. The coils are electrically connected to drive the generation of a magnetic field in the Y direction. The two X-axis electromagnetic coils are connected in parallel or in series, and the two Y-axis electromagnetic coils are connected in parallel or in series. The controller reads the magnetic field parameters from the host computer and compiles the magnetic field parameters into a PWM wave control signal that can be received by the X-axis electromagnetic coil driver, the Y-axis electromagnetic coil driver, and / or the Z-axis electromagnetic coil driver. The X-axis electromagnetic coil driver, the Y-axis electromagnetic coil driver, and / or the Z-axis electromagnetic coil control the power supply output current according to the PWM wave control signal to control the Z-axis electromagnetic coil, the two X-axis electromagnetic coils, and / or the two Y-axis electromagnetic coils to generate a magnetic field.

5. The portable magnetic control device for additive manufacturing according to claim 1, characterized in that: The magnetic field generating base is detachably fixed in the 3D printing system or magnetic field manipulation device, wherein the 3D printing system is a photopolymerization 3D printing system or a material extrusion 3D printing system.

6. A portable magnetic control method for additive manufacturing, applied to the portable magnetic control device for additive manufacturing as described in any one of claims 1-5, characterized in that, Includes the following steps: Set the required magnetic field, which can be a magnetic field of a certain direction and magnitude, a spatial rotating magnetic field, or a conical spiral magnetic field; Control the Z-axis electromagnetic coil, two X-axis electromagnetic coils, and / or two Y-axis electromagnetic coils to generate the required magnetic field.

7. The portable magnetic manipulation method for additive manufacturing according to claim 6, characterized in that: When the required magnetic field is of a certain direction and magnitude, the input currents are as follows: in, , , To input current into the X-axis electromagnetic coil, Y-axis electromagnetic coil, and Z-axis electromagnetic coil respectively under a magnetic field of a certain direction and magnitude, All are linear relationship coefficients. A The magnitude of the magnetic field. The pitch angle is the angle of a magnetic field of a certain direction and magnitude. It is the direction angle under a magnetic field of a certain direction and magnitude; Among them, the linear relationship coefficient satisfy: ， ， ； In the formula, , and These are the magnetic field components along the X, Y, and Z axes, respectively.

8. The portable magnetic manipulation method for additive manufacturing according to claim 6, characterized in that: When the required magnetic field is a spatial rotating magnetic field, the input currents are as follows: in, , , The current input to the X-axis, Y-axis, and Z-axis electromagnetic coils is given under a rotating magnetic field in space. The pitch angle under a rotating magnetic field in space. For frequency, For time, A The magnitude of the magnetic field. All coefficients are linearly related and satisfy the following: ， ， ； In the formula, , and These are the magnetic field components along the X, Y, and Z axes, respectively.

9. The portable magnetic manipulation method for additive manufacturing according to claim 6, characterized in that: When the required magnetic field is a planar rotating magnetic field, the input currents along the X and Y axes are respectively: in, The current input to the X-axis and Y-axis electromagnetic coils is given under a planar rotating magnetic field. All are linear relationship coefficients. For frequency, Let A be the time, and A be the magnitude of the magnetic field. The current input to the Z-axis electromagnetic coil under a spatial rotating magnetic field is 0; Among them, the linear relationship coefficient satisfy: ， ； In the formula, , These are the magnetic field components along the X and Y axes, respectively.

10. The portable magnetic manipulation method for additive manufacturing according to claim 8, characterized in that: When the required magnetic field is a conical spiral magnetic field, the current in the X-axis and Y-axis gradually decreases while the current in the Z-axis gradually increases.

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