Portable magnetic control system applied to additive manufacturing and control method

Abstract

The invention provides a portable magnetic control system applied to additive manufacturing and a control method, the portable magnetic control system comprises a magnetic field generation base, the magnetic field generation base is provided with a containing cavity, an operation platform, a Z-axis electromagnetic coil, an X-axis electromagnetic coil and a Y-axis electromagnetic coil are arranged in the magnetic field generation base, the operation platform is arranged in the containing cavity, an operation part is placed on the operation platform, and the Z-axis electromagnetic coil and the Y-axis electromagnetic coil are arranged in the containing cavity. The Z-axis electromagnetic coil is arranged in the containing cavity and below the operation platform, the two X-axis electromagnetic coils are arranged in the containing cavity and oppositely arranged with the operation platform as the center, and the two Y-axis electromagnetic coils are arranged in the containing cavity and oppositely arranged with the operation platform as the center. The control system has portability, universality and the capacity of generating multiple magnetic fields and can be easily integrated into various 3D printing devices, the control method can flexibly and efficiently generate the needed magnetic fields according to the specific requirements of the 3D printing devices, and therefore the flexibility and the high efficiency of magnetic field control are achieved.

Description

Technical Field

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

[0002] With the development of science and technology, functional magnetic materials have shown broad application prospects in many fields, especially in the fields of magnetically driven microrobots and magnetic flexible devices. However, the further application of these functional magnetic materials depends largely on whether structures with special geometric shapes and magnetization characteristics can be manufactured. Traditional manufacturing technology has limitations in dealing with complex geometric shapes and internal structures, while additive manufacturing (3D printing) technology has effectively solved this problem by virtue of its ability to accurately shape complex shapes and internal structures based on computer models. In this context, magnetic field-assisted 3D printing technology has emerged innovatively. This technology realizes the 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 is to combine the high-precision layer-by-layer construction 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 the construction of complex shapes, but also gives the printed parts unique magnetic properties, making it show unlimited possibilities in the fields of microrobots, biomedicine, electronic engineering, etc. As the core component of magnetic field-assisted 3D printing technology, the magnetic manipulation system has the ability to generate and control magnetic fields in a certain direction, guiding the magnetic particles in the printing material to be arranged in an orderly manner according to the preset direction, thereby constructing a structure with a specific magnetization distribution.

[0003] However, current magnetic field-assisted 3D printing technologies mostly integrate the magnetic manipulation system directly into specific printing equipment, which not only increases the overall complexity of the system, but also limits the versatility and adaptability of the magnetic manipulation system between different operating platforms. Summary of the invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a portable magnetic manipulation system and a manipulation method for additive manufacturing. The manipulation system is portable, versatile, and has the ability to generate a variety of magnetic fields. It can be easily integrated into various types of 3D printing equipment, and the manipulation method can flexibly and efficiently generate the required magnetic field according to the specific needs of the 3D printing device, thereby achieving the flexibility and efficiency of magnetic field manipulation, significantly improving the controllability of the magnetic field in magnetic field-assisted 3D printing, and at the same time can play a beneficial role in multiple fields such as magnetic material manipulation, biomedicine, and microfluidics.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

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

[0007] A magnetic field generating base, wherein the magnetic field generating base has a containing cavity, and an operating platform, a Z-axis electromagnetic coil, an X-axis electromagnetic coil and a Y-axis electromagnetic coil are arranged in the magnetic field generating base, wherein

[0008] The operating platform is arranged in the accommodating cavity, and an operating member is placed on the operating platform;

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

[0010] The two X-axis electromagnetic coils are disposed in the accommodating cavity and are arranged opposite to 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 arranged in the accommodating cavity and are relatively arranged with the operating platform as the center, and the two Y-axis electromagnetic coils extend along the 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 arranged 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 arranged in the accommodating cavity, and the magnetic field generating cover and the magnetic field generating base are both provided with a plurality of heat dissipation holes.

[0013] Furthermore, a plurality of snap-fit ​​structures are provided in the accommodating cavity, and each of the snap-fit ​​structures is used for snap-fitting with the Y-axis electromagnetic coil or the X-axis electromagnetic coil.

[0014] Furthermore, it also includes a control unit, the control unit includes a power supply, a driver, a controller and a host computer, the power supply and the driver are electrically connected to the controller, the controller is electrically connected to the host computer, the power supply is used for power supply, 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 the generation of a magnetic field in the Z direction, the X-axis electromagnetic coil driver is electrically connected to the two X-axis electromagnetic coils to drive the generation of a magnetic field in the X direction, the Y-axis electromagnetic coil driver is electrically connected to the two Y-axis electromagnetic coils The magnetic coils are electrically connected to drive and generate 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 transmitted 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 a 3D printing system or a magnetic field manipulation device, and the 3D printing system is a light-curing 3D printing system or a material extrusion 3D printing system.

[0016] A portable magnetic manipulation method for additive manufacturing, applied to the above-mentioned portable magnetic manipulation system for additive manufacturing, comprises the following steps:

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

[0018] The Z-axis electromagnetic coil, the two X-axis electromagnetic coils and / or the two Y-axis electromagnetic coils are controlled to generate a desired magnetic field.

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

[0020]

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

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

[0023]

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

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

[0026]

[0027] Among them, I X′ I Y′ is the current input to the X-axis electromagnetic coil and the Y-axis electromagnetic coil under the plane rotating magnetic field, α1 and α2 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 of the X-axis and the Y-axis are gradually reduced and the current of the Z-axis is gradually increased.

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

[0031] (1) Traditional magnetic field manipulation systems used to assist 3D printing are mostly integrated with the printing system, which increases the overall complexity of the equipment and weakens the versatility of the magnetic field manipulation system in different scenarios. The design of a portable magnetic manipulation system can solve this problem well. The overall system can be used in material extrusion 3D printing scenarios and can also be used in light-curing 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 multiple types of special magnetic fields that traditional magnetic field manipulation systems do not have, such as regional approximate gradient magnetic fields, rotating magnetic fields, conical spiral magnetic fields, etc., solving the problem of the relatively single type of magnetic field generated by traditional magnetic manipulation systems used to assist 3D printing.

[0033] (3) The circular printing platform in the center of the heat sink is arranged in a sunken position so that it can be simultaneously acted upon by the Z-axis electromagnetic coil, two X-axis electromagnetic coils, and two Y-axis electromagnetic coils. Since the distance to the coils is close enough, the magnetic field strength is sufficient to control the magnetic particles, thus solving the problem of weak magnetic field generated by the traditional magnetic manipulation system used to assist 3D printing.

[0034] (4) The overall system design concept is replicable, the control logic is simple, and it is highly malleable and can be flexibly adjusted to cope with changing environments and needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0036] Figure 1 This is a schematic diagram of the structure in which the magnetic field generating base and the magnetic field generating cover are separated from each other in the present invention;

[0037] Figure 2 An exploded view of the portable magnetic manipulation system of the present invention;

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

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

[0040] Figure 5 A schematic diagram of the portable magnetic manipulation system of the present invention applied to a light-curing 3D printing system;

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

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

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

[0044] Fig. 9 It is a schematic diagram of a magnetic field of a certain direction and a certain size of the portable magnetic control system of the present invention;

[0045] Fig.10 This is a relationship diagram between the single-axis magnetic field and the current at the center of the circular printing platform of the portable magnetic manipulation system of the present invention;

[0046] Fig.11A schematic diagram of generating a regional gradient magnetic field for the portable magnetic manipulation system of the present invention;

[0047] Fig.12 A schematic diagram of generating a rotating magnetic field for the portable magnetic manipulation system of the present invention;

[0048] Fig.13 Schematic diagram of analysis of samples printed by the portable magnetic manipulation system of the present invention.

[0049] Among them, 100, magnetic manipulation system; 1, magnetic field generating base; 101, accommodating 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-on structure; 8, heat dissipation holes; 9, reinforcing ribs; 10, circular ring; 11, plastic screws; 12, power supply; 13, driver; 14, controller; 15, small magnetic needle; 16, circular mesh printing sample; 17, magnetic particles inside the printed sample; 200, material extrusion 3D printing system; 300, photocuring 3D printing system. DETAILED DESCRIPTION

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

[0051] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0052] Example 1

[0053] Some of the magnetic control parts in existing magnetic field-assisted 3D printing systems use simple magnets as magnetic field sources, but cannot accurately control the direction of the magnetic field; others integrate complex magnetic field equipment with printing equipment. Although this achieves precise control of the magnetic field, it increases the complexity of the overall system and limits the versatility of the portable magnetic control system 100 in different printing systems.

[0054] In response to the above problems, the present invention innovatively proposes a portable magnetic manipulation system 100 for additive manufacturing—P-MagDisk. The portable magnetic manipulation system 100 is characterized by its high portability, versatility and ability to generate a variety of magnetic fields. It can be easily integrated into various types of 3D printing equipment, achieving flexibility and efficiency in magnetic field manipulation. P-MagDisk can generate the required magnetic field according to the needs of the printing device through the designed electromagnetic coil portable magnetic manipulation system 100 and magnetic field manipulation algorithm. Whether it is generating a gradient magnetic field or a rotating magnetic field, P-MagDisk can achieve it.

[0055] The portable magnetic manipulation system 100 for additive manufacturing provided in this embodiment can be divided into a hardware module and a software module. Figure 1-Figure 3 As shown, the hardware module includes a magnetic field generating base 1, the magnetic field generating base 1 has a containing cavity 101, and an operating platform 2, a Z-axis electromagnetic coil 3, an X-axis electromagnetic coil 4 and a Y-axis electromagnetic coil 5 are arranged in the magnetic field generating base 1.

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

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

[0058] The two X-axis electromagnetic coils 4 are disposed in the accommodating cavity 101 and are arranged opposite to 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 arranged in the accommodating cavity 101 and are relatively arranged with the operating platform 2 as the center, and the two Y-axis electromagnetic coils 5 extend along the 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.

[0060] In this embodiment, the required magnetic field is set 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 the required magnetic field, so as to control the operating member and realize 3D printing of the operating member or magnetic control of the operating member.

[0061] In this embodiment, for the electromagnetic coil, it is first clear that a single electromagnetic coil can only generate a magnetic field in a single direction. If a magnetic field in any direction is to be generated, the arrangement of the electromagnetic coils needs to be designed in combination. In order to generate a magnetic field in any desired direction during printing, the portable magnetic manipulation system 100 applied to additive manufacturing is arranged according to the right-hand coordinate system, where the X-axis and the Y-axis are composed of two electromagnetic coils, and the Z-axis has one electromagnetic coil. Since the control object of the portable magnetic manipulation system 100 applied to additive manufacturing is the magnetic particles inside the magnetic material, the magnetic field force generated by the output magnetic field of the portable magnetic manipulation system 100 only needs to overcome the force between the particles, and the magnetic field strength is in the order of mT. When the portable magnetic manipulation system 100 applied to additive manufacturing in this embodiment is fed with a current of 10A, a maximum magnetic field of 18mT can be generated along the X direction or the Y direction at the intersection of the normal lines of the five electromagnetic coils (i.e., the center of the operating platform 2), and a maximum magnetic field of 54mT can be generated along the Z direction. The magnetic field strength is sufficient to control and rearrange the magnetic particles inside the material.

[0062] In this embodiment, Figure 1-Figure 3 As shown, the magnetic field generating base 1 is a rectangular cavity structure. In order to make the portable magnetic control system 100 easy to carry and install, it also includes a magnetic field generating cover 6, which is a rectangular plate-like structure. The operating platform 2 is arranged below the magnetic field generating cover 6. Considering that the electromagnetic coil has an impact on the surrounding magnetic materials when working, the plastic screws 11 commonly used on the market are used to detachably connect the magnetic field generating base 1 and the magnetic field generating cover 6 so that the operating platform 2 can be selectively arranged in the accommodating cavity 101. The accommodating cavity 101 needs to be able to accommodate five electromagnetic coils, so there are certain requirements for the strength of the magnetic field generating base 1. In order to increase the strength of the magnetic field generating base 1, reinforcing ribs 9 are arranged around the accommodating cavity 101 to strengthen the connection between the bottom and the side of the magnetic field generating base 1, and further improve the strength and rigidity of the magnetic field generating base 1. In the portable magnetic manipulation system 100 used for additive manufacturing, the main function of the magnetic field generating base 1 is to provide stable support for the electromagnetic coil and provide 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 when working, heat dissipation holes 8 of different sizes are left 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 further 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 arranged below the magnetic field generating cover 6. In the specific implementation manner of this embodiment, the fixing member is a cylinder, the top of the fixing member is welded or integrally connected to the magnetic field generating cover 6, and the bottom of the fixing member is welded 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, the operating platform 2 is arranged in the accommodating 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, the X-axis electromagnetic coil 4 and the Y-axis electromagnetic coil 5 in the accommodating cavity 101 can be adjusted.

[0065] In this embodiment, in order to take into account the stability of heat dissipation and support, the clamping structure 7 is used to clamp 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. In the specific implementation of this embodiment, the clamping structure 7 is two V-shaped blocks arranged at a certain distance, and the bottom of the V-shaped block is fixed to the accommodating cavity 101, and the two V-shaped blocks provide support and sufficient heat dissipation space for the X-axis electromagnetic coil 4 and the Y-axis electromagnetic coil 5. Since the Z-axis electromagnetic coil 3 in the center is small in size, a circular ring 10 is selected to clamp the Z-axis electromagnetic coil 3 with a plastic screw 11 to fix the Z-axis electromagnetic coil 3. In addition, in order to serve the 3D printing system and face the application of millimeter-micrometer-level printing devices, the operating platform 2 and the magnetic field generating cover 6 are not in the same horizontal plane, but are sunk a certain distance relative to the magnetic field generating cover 6 so that the operating platform 2 is parallel to the central axis of the X-axis electromagnetic coil 4 and the Y-axis electromagnetic coil 5, and the diameter of the operating platform 2 is 70 to 100 mm. This arrangement enables the printing material in 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", and the installation of the overall structure can be completed by simply placing the magnetic field generating cover 6 on the magnetic field generating base 1 according to the orientation.

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

[0067] In this embodiment, Figure 6-Figure 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 the driver 13 are electrically connected to the controller 14, and the controller 14 is electrically connected to the host computer. The power supply 12 is used for power supply. 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 the Z-axis electromagnetic coil 3 to drive the generation of a magnetic field in the Z direction. The X-axis electromagnetic coil driver is electrically connected to the two X-axis electromagnetic coils 4 to drive the generation of a magnetic field in the X direction. The Y-axis electromagnetic coil driver is electrically connected to the two Y-axis electromagnetic coils 4 to drive the generation of a magnetic field in the X direction. The coil 5 is electrically connected to drive the generation of a magnetic field in the Y direction, the two X-axis electromagnetic coils 4 are connected in parallel or in series, and the two Y-axis electromagnetic coils 5 are connected in parallel or in series. The controller reads the magnetic field parameters transmitted 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 and / or the Y-axis electromagnetic coil driver, and the 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 model is CSP-3000 power supply, and the driver model is CoPley driver. CSP-3000 power supply mainly powers CoPley driver. The myRIO controller reads the magnetic field parameters transmitted from the host computer software, and 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 controls the power supply output current to control the electromagnetic coil according to the control signal.

[0069] The software part of the portable magnetic manipulation system 100 for additive manufacturing mainly includes the magnetic field control algorithm of the portable magnetic manipulation system 100, the LabVIEW control interactive interface (host computer program) and the COMSOL magnetic field simulation model. According to the Biot-Savart law, the magnetic field generated by the electromagnetic coil at a certain point is proportional to the current. Therefore, to control the magnetic field at a certain point, it is only necessary to control the current input to the electromagnetic coil. The magnetic field control algorithm is based on this. Through the input magnetic field parameters, the corresponding current is calculated, and the current signal is converted into a PWM wave signal with different duty cycles through the algorithm and sent. This is the logic of the magnetic field control algorithm. The LabVIEW control interactive interface, as a host computer program, can input the required magnetic field parameters, set the wiring port of the myRIO controller, and compile and run the magnetic field control code. The COMSOL magnetic field simulation model can truly reflect the size and direction of the magnetic field generated by the portable magnetic manipulation system 100 for additive manufacturing. Combined with the magnetic field control program, the magnetic field control code can be optimized in a simulation environment.

[0070] like Figure 4 and Figure 5 As shown, the design of the portable magnetic manipulation system 100 used for additive manufacturing determines that the portable magnetic manipulation system 100 has great convenience. In practical applications, the portable magnetic manipulation system 100 used for additive manufacturing can be placed in a material extrusion 3D printing system 200 or a light-curing 3D printing system 300, and the premise of application is to adjust the printing height of the 3D printing system. Since the portable magnetic manipulation system 100 used for additive manufacturing is relatively low in height, general 3D printing systems can accommodate the portable magnetic manipulation system 100. In addition, the portable magnetic manipulation system 100 can also be used alone as a magnetic field manipulation device, which can control magnetic particles, small magnetic devices, etc. In summary, the portable magnetic manipulation system 100 used for additive manufacturing is a set of portable magnetic manipulation systems 100 with significant application value and diversified application scenarios.

[0071] The magnetic field generating base 1 can be detachably fixed in a 3D printing system or a magnetic field manipulation device. The 3D printing system is a light-curing 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 manipulation 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 manipulation system in different scenarios. The design of the portable magnetic manipulation system 100 can solve this problem well. The overall system can be used in material extrusion 3D printing scenarios and can also be used in light-curing 3D printing scenarios, and has good portability.

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

[0075] (3) The circular printing platform at the center of the heat dissipation cover is arranged in a sunken manner so that it can be simultaneously acted upon by the Z-axis electromagnetic coil 3, two X-axis electromagnetic coils 4, and two Y-axis electromagnetic coils 5. Since the distance to the coils is close enough, the magnetic field strength is sufficient to control the magnetic particles, thus solving the problem of weak magnetic field generated by the conventional portable magnetic manipulation system 100 used to assist 3D printing.

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

[0077] Example 2

[0078] Embodiment 2 provides a portable magnetic manipulation method for additive manufacturing, which is applied to the above-mentioned portable magnetic manipulation system 100 for additive manufacturing, and includes the following steps:

[0079] Step S1: setting a required magnetic field, which is a magnetic field of a certain direction and magnitude, a plane rotating magnetic field, a space rotating magnetic field or a conical spiral magnetic field;

[0080] Step S2: 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 required magnetic field.

[0081] like Fig. 9 As shown, it is a schematic diagram of a magnetic field of a certain direction and a certain size of the portable magnetic manipulation system of the present invention. When the required magnetic field is a magnetic field of a certain direction and a certain size, in order to allow the portable magnetic manipulation system 100 used in additive manufacturing to generate a magnetic field of a certain direction and a certain size. First of all, it is clear that the magnetic field generating element of the portable magnetic manipulation system 100 is five combined electromagnetic coils, the number of turns of the X-axis electromagnetic coil 4 and the Y-axis electromagnetic coil 5 are both 340 turns, and there are two X-axis electromagnetic coils 4 and two Y-axis electromagnetic coils 5 arranged on the X-axis and Y-axis, respectively. Therefore, the equivalent number of turns of the X-axis coil is 680 turns, and the equivalent number of turns of the Y-axis coil is also 680 turns. The number of turns of the Z-axis coil is 485 turns. Since the magnetic field generated by the portable magnetic manipulation system 100 is outside the coil, the specific area is the operating platform 2. According to the simulation results, the magnetic field distribution on the operating platform 2 is uneven, and the magnetic field at the center of the operating platform 2 (i.e., the center of the circle) is the weakest, and the center is subsequently referred to as the coil magnetic field working point. For magnetron printing, a too precise magnetic field is not required, and the magnetic field only needs to be greater than a certain threshold value (the threshold value is determined by the characteristics of the magnetron 3D printing material). Therefore, if the threshold value is 10mT, it only needs the magnetic field at the coil magnetic field working point to be greater than 10mT, and then the magnetic field on the entire operating platform 2 is also greater than 10mT, and both exceed the threshold value, thus satisfying the conditions for magnetron printing.

[0082] For a magnetic field at a certain point in space, the magnetic field and the current are linearly related, that is, Figure 7The relationship between magnetic field and current is shown in the figure. This formula is related to the number of coil turns and the distance from the center of the coil to the point. For the X and Y axes, the equivalent number of turns is 680 turns, and the distance to the point is 39 mm. The distance from the center of the Z axis coil to the point is 8 mm, and the equivalent number of turns is 485 turns. According to the Biot-Savart law, the magnetic field at a certain point is linearly related to the current, the magnetic field is linearly related to the number of turns, and the magnetic field is inversely proportional to the distance (r) in cubic proportion. Therefore, although the Z axis coil has fewer turns, it is closer to the working point of the coil, and the magnetic field attenuates less, so the same current can generate a larger magnetic field. The X and Y axis coils are far away from the point, and the same current can only generate a smaller magnetic field.

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

[0084] B X =α1I X (1)

[0085] B Y =α2I Y (2)

[0086] B Z =βI Z (3)

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

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

[0089] Therefore, for the portable magnetic manipulation system 100 to generate a magnetic field in any fixed direction, the specific magnetic field is represented as follows: Fig.11 If the portable magnetic manipulation system 100 is to generate a synthetic magnetic field with a magnetic field size of A in mT, a direction angle of d0, and a pitch angle of p0, the magnetic field components in the X, Y, and Z directions can be inferred to be:

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

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

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

[0093] By making equations (4)-(6) equal to equations (1)-(3), we can obtain the input currents of the X, Y, and Z axes respectively:

[0094]

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

[0096] Therefore, in the specific implementation of this embodiment, if a magnetic field with a magnitude of 10 mT, a direction angle of 30°, and a pitch angle of 45° is to be generated, the input three-axis current can be obtained as follows:

[0097]

[0098] Therefore, it is only necessary to control the driver to output the above three-axis current to make the coil magnetic field working point generate a fixed-direction magnetic field with a magnitude of 10mT, a direction angle of 30°, and a pitch angle of 45°.

[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 applied should also change with time, that is, the current applied should be alternating current. Therefore, sin(2πft) and cos(2πft) are some parameters of alternating current, where f is the frequency, indicating the number of times the magnetic field changes in 1 second. In the 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 adjusted mainly by adjusting the frequency parameter.

[0100]

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

[0102] In the specific implementation of this embodiment, if the pitch angle is 30°, equations (10)-(12) are changed to:

[0103]

[0104] When the required magnetic field is a plane rotating magnetic field, the Z-axis coil is not energized because the magnetic field is only on the XY plane, and the pitch angle of the magnetic field is 0°. In addition, since the magnetic field vectors of the generated uniform plane rotating magnetic field are the same at any position at any time, there is no concept of direction angle. At this time, the input three-axis current is:

[0105]

[0106] When the required magnetic field is a conical spiral magnetic field: when the currents of the X-axis and the Y-axis gradually decrease, and the current of the Z-axis gradually increases, the pitch angle continues to increase, and the pitch angle is continuously increased 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 feature of this magnetic field is spiral progression, the magnetic field strength gradually increases and the direction gradually follows the Z axis, and it can be mainly used to break up particles. At the initial moment, the magnetic field is weak and the pitch angle is small. At this time, the particles in the surrounding area will gather, and then as the magnetic field increases, the pitch angle increases, and the particles stand and distribute between the particles. At this time, the two particles can be understood as two bar magnets, and both have their N poles facing the Z direction. At this time, the particles will be repelled and dispersed. This also shows that the portable magnetic manipulation system 100 is not limited to assisting 3D printing, but can also be used as a magnetic manipulation device.

[0108] The control strategy of the overall portable magnetic manipulation system 100 is as follows: Figure 6 . Input the required magnetic field parameters in the upper computer LabVIEW control terminal, which is connected to the myRIO controller. The controller solves the input parameters to obtain the current signal of the coil, and converts the current signal into a PWM wave (control signal) with different duty cycles through the magnetic field algorithm. After the compilation is completed, the controller sends the signal to the CoPley driver through the control bus. The driver reads the control signal and adjusts the power supply to output 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, in order to further improve the accuracy of the portable magnetic manipulation system 100 in generating the magnetic field, a three-dimensional magnetic sensor is used to measure the magnetic field parameters of the operating platform 2 and feed it back to the LabVIEW control terminal, thereby further regulating the output of the current. The three drivers used in this portable magnetic manipulation system 100 respectively control the magnetic field components of the three axes of XYZ. The wiring ports between the driver and the controller are pre-set. The interface connections of this portable magnetic manipulation system 100 are as follows: Figure 7 .

[0109] Fig.10It is the relationship between the uniaxial magnetic field and the current at the center of the operating platform 2 of the portable magnetic manipulation system 100. Since the portable magnetic manipulation system 100 mainly serves the 3D printing system, the uniformity of the magnetic field is not an important parameter, but the strength of the magnetic field affects whether the magnetic device that meets the requirements can be printed. After the portable magnetic manipulation system 100 is running, the magnetic field at the center of the operating platform 2 is the weakest, that is, the surrounding magnetic fields are greater 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 turn, and the magnetic device that meets the requirements can be successfully printed. To control the magnetic field strength at this point, it is necessary to obtain the relationship between the magnetic field and the current at this point. The relationship between the magnetic field and the current at this point obtained under experimental measurement is shown in the figure. The coefficient of this linear relationship is determined by the electromagnetic coil used. If the electromagnetic coil is replaced, the coefficient needs to be re-measured.

[0110] Fig.11 The diagram is a schematic diagram of the portable magnetic manipulation system 100 generating a regional gradient magnetic field. In order to visualize the magnetic field, small magnetic needles are evenly sprinkled in the operating platform 2, and then the portable magnetic manipulation system 100 is started, and the portable magnetic manipulation system 100 is set to generate a magnetic field at an angle of 45 degrees to the positive direction of the X-axis. Under the action of the magnetic field, the small magnetic needle inside the operating platform 2 turns as the magnetic field is generated. This example proves that the portable magnetic manipulation system 100 has the function of generating a magnetic field in a certain direction.

[0111] Fig.12 Schematic diagram of the portable magnetic manipulation system 100 generating an XY plane rotating magnetic field. Similarly, small magnetic needles are sprinkled in the operating platform 2. The system is started and set to generate an XY plane rotating magnetic field rotating around the Z axis. Under the action of the rotating magnetic field, the small magnetic needle inside the operating platform 2 also rotates. However, since the magnetic field of this system is generated by an electromagnetic coil, the magnetic field inside the operating platform 2 is not uniform, but for the auxiliary 3D printing system, this effect is almost negligible, and the weak magnetic field gradient does not affect the overall distribution of magnetic particles.

[0112] Fig.13 The portable magnetic manipulation system 100 is used to assist in the sample analysis of printing on the material extrusion 3D printing system 200. Before printing, the portable magnetic manipulation system 100 is set to generate a magnetic field along the Y direction, and then a circular mesh sample is printed through the 3D printer. After printing is completed, the magnetic particles inside the printed sample are distributed along the Y direction. This application example also proves that the portable magnetic manipulation system 100 can be well applied to the 3D printing system.

[0113] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A portable magnetic manipulation system for additive manufacturing, characterized in that: include: A magnetic field generating base, wherein the magnetic field generating base has a containing cavity, and an operating platform, a Z-axis electromagnetic coil, an X-axis electromagnetic coil and a Y-axis electromagnetic coil are arranged in the magnetic field generating base, wherein The operating platform is arranged in the accommodating cavity, and an operating member is placed on the operating platform; The Z-axis electromagnetic coil is disposed in the accommodating cavity and below the operating platform, and the Z-axis electromagnetic coil extends along a first direction to generate a magnetic field in a first direction; The two X-axis electromagnetic coils are disposed in the accommodating cavity and are arranged opposite to 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 arranged in the accommodating cavity and are relatively arranged with the operating platform as the center, and the two Y-axis electromagnetic coils extend along the 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.

2. The portable magnetic manipulation system for additive manufacturing according to claim 1, characterized in that: It also includes a magnetic field generating cover, the operating platform is arranged 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 arranged in the accommodating cavity, and the magnetic field generating cover and the magnetic field generating base are both provided with a plurality of heat dissipation holes.

3. The portable magnetic manipulation system for additive manufacturing according to claim 1, characterized in that: A plurality of clamping structures are arranged in the accommodating cavity, and each of the clamping structures is used for clamping and cooperating with the Y-axis electromagnetic coil or the X-axis electromagnetic coil.

4. The portable magnetic manipulation system for additive manufacturing according to claim 1, characterized in that: It also includes a control unit, which includes a power supply, a driver, a controller and a host computer. The power supply and the driver are electrically connected to the controller, the controller is electrically connected to the host computer, the power supply is used for power supply, 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 the generation of a magnetic field in the Z direction, the X-axis electromagnetic coil driver is electrically connected to the two X-axis electromagnetic coils to drive the generation of a magnetic field in the X direction, the Y-axis electromagnetic coil driver is electrically connected to the two Y-axis electromagnetic coils The two X-axis electromagnetic 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 transmitted 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 manipulation system for additive manufacturing according to claim 1, characterized in that: The magnetic field generating base can be detachably fixed in a 3D printing system or a magnetic field manipulation device, and the 3D printing system is a light-curing 3D printing system or a material extrusion 3D printing system.

6. A portable magnetic manipulation method for additive manufacturing, applied to the portable magnetic manipulation system for additive manufacturing as claimed in any one of claims 1 to 5, characterized in that: The following steps are involved: Set the required magnetic field, which is a magnetic field of a certain direction and magnitude, a spatial rotating magnetic field or a conical spiral magnetic field; The Z-axis electromagnetic coil, the two X-axis electromagnetic coils and / or the two Y-axis electromagnetic coils are controlled to generate a desired magnetic field.

7. The portable magnetic manipulation method for additive manufacturing according to claim 6, characterized in that: When the required magnetic field is a magnetic field of a certain direction and magnitude, the input currents are: Among them, I X ,I Y ,I Z The currents of the X-axis electromagnetic coil, Y-axis electromagnetic coil, and Z-axis electromagnetic coil are respectively input under a magnetic field of a certain direction and a certain magnitude. α1, α2, and β are all linear relationship coefficients. p0 is the pitch angle under a magnetic field of a certain direction and a certain magnitude. d0 is the direction angle under a magnetic field of a certain direction and a certain magnitude.

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

9. The portable magnetic manipulation method for additive manufacturing according to claim 6, characterized in that: When the required magnetic field is a plane rotating magnetic field, the currents input into the X and Y axes are: Among them, I X′ I Y′ is the current input to the X-axis electromagnetic coil and the Y-axis electromagnetic coil under the plane rotating magnetic field, α1 and α2 are linear relationship coefficients, f is the frequency, and t is the time; The current input to the Z-axis electromagnetic coil under the spatial rotating magnetic field is 0.

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 currents of the X-axis and the Y-axis are gradually reduced and the current of the Z-axis is gradually increased.

Images