Intelligent hot bed system of fused deposition modeling 3D printer

Abstract

The intelligent hot bed system of the fused deposition modeling 3D printer comprises a first fixing plate and a second fixing plate which are oppositely arranged, a plurality of gear seats are fixed between the two fixing plates, a transmission gear is rotationally installed in a gear cavity of each gear seat, and a lead screw penetrating through the two fixing plates is in threaded connection with the interior of a center hole of each transmission gear; a hot bed unit platform is hinged to the top of the lead screw penetrating through the first fixing plate through a universal joint, multiple sets of cameras installed on the 3D printer are arranged above the hot bed unit platform, a driving device is fixed to the portion, close to the lead screw, of the surface of the first fixing plate, and the multiple sets of cameras and the driving device are electrically connected with a control module. A driving shaft of the driving device is sleeved with a driving gear meshed with the transmission gear exposed out of the notch of the gear cavity, and a moving guide rod connected with an existing moving mechanism on the 3D printer in a matched mode is fixed to the bottom face of the second fixing plate. According to the system, dynamic adaptation of a supporting area is achieved through the independent modular thermal bed unit, and the bottom face supporting area can be obviously reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of 3D printers, and in particular to an intelligent hot bed system for a fused deposition modeling 3D printer. Background Art

[0002] Fused Deposition Modeling (FDM) is a method of heating and melting various hot-melt filamentous materials (such as wax, ABS, and nylon) to form a shape, and is a type of 3D printing technology. The temperature of the hot-melt material is always slightly higher than the curing temperature, while the temperature of the formed part is slightly lower than the curing temperature. After the hot-melt material is extruded from the nozzle, it immediately fuses with the previous layer. After a layer is deposited, the workbench descends by the thickness of one layer at a predetermined increment, and then continues to melt and spray deposit until the entire solid part is completed.

[0003] Traditional fused deposition modeling 3D printers use an integral hot bed as a support platform during the printing process. However, the inventors of the present application have found through research that this design has the following significant defects: First, the fixed integrated (integral) hot bed structure is prone to thermal deformation during continuous heating, resulting in a decrease in the flatness of the printing platform, directly affecting the dimensional accuracy and surface quality of the formed part; Second, the traditional hot bed cannot be dynamically adjusted according to the geometric characteristics of the printing model (such as the irregular anatomical surface of a biological joint commonly found in the medical field), and it is difficult to achieve a differential support effect (such as generating micro support points in bone depressions or overhanging parts); More critically, the support structures generated by existing slicing algorithms usually completely cover the bottom surface of the model, which not only causes waste of support materials and prolongs the printing time, but also causes damage or residual marks on the model surface when removing the support. Summary of the Invention

[0004] In view of the technical problems that the existing fixed integrated (monolithic) hot bed structure is prone to thermal deformation during continuous heating, resulting in a decrease in the flatness of the printing platform, directly affecting the dimensional accuracy and surface quality of the formed parts. At the same time, the traditional hot bed cannot be dynamically adjusted according to the geometric features of the printing model, making it difficult to match the irregular anatomical surfaces of biological joints, and it is difficult to achieve a differential support effect when printing animal experiment fixing devices and human joint fixing braces. In addition, the support structures generated by the existing slicing algorithms usually completely cover the bottom surface of the model, which not only causes waste of support materials and prolongs the printing time, but also leads to surface damage or residual traces of the model when removing the support. The present invention provides an intelligent hot bed system for a fused deposition modeling 3D printer, which realizes the dynamic adaptation of the support area through independent modular hot bed units, matches the irregular anatomical surfaces of biological joints, and at the same time, based on the support optimization algorithm for model feature recognition, only generates micro support points at the concave or overhanging parts of the bone, which not only retains the surface details of the model, but also avoids excessive adhesion between the support surface and the model. Thus, on the premise of ensuring the forming quality, the bottom surface support area is significantly reduced, the printing efficiency and the finished product rate are improved, and a new solution is provided for the intelligent manufacturing of personalized medical devices.

[0005] To solve the above technical problems, the present invention adopts the following technical solutions:

[0006] An intelligent hot bed system for a fused deposition modeling 3D printer, comprising a first fixed plate and a second fixed plate arranged opposite to each other. A plurality of gear seats are fixedly connected between the first fixed plate and the second fixed plate. A transmission gear is rotatably installed in the gear cavity of each gear seat. A notch is formed on the side surface of the gear seat, and a part of the transmission gear protrudes from the notch. A lead screw passing through the first fixed plate and the second fixed plate is threadedly connected in the central hole of the transmission gear. The top of the lead screw passing through the first fixed plate is hinged to a hot bed unit platform through a universal joint. Above the hot bed unit platform, a plurality of groups of cameras installed on the 3D printer are provided. A driving device is fixedly connected to the surface of the first fixed plate near the lead screw. All the plurality of groups of cameras and the driving devices on the surface of the first fixed plate are electrically connected to a control module. The driving shaft of the driving device passes through the first fixed plate to the second fixed plate. A driving gear is fixedly sleeved on the driving shaft between the first fixed plate and the second fixed plate. The driving gear meshes with the transmission gear protruding from the notch. Two relatively arranged moving guide rods are fixedly connected to the bottom surface of the second fixed plate. One end of the moving guide rod is cooperatively connected with an existing moving mechanism on the 3D printer.

[0007] Compared with the existing technology, the intelligent hot bed system of the fused deposition modeling 3D printer provided by the present invention is composed of multiple movable hot bed unit platforms. The hot bed unit platforms adopt an independent modular layout. Each hot bed unit platform is hinged to the lead screw through a universal joint. It can be independently raised and lowered and coordinated. It can be dynamically adjusted according to the shape of the printed object, support requirements and printing stage requirements, so as to better fit the anatomical curved surface structure of the organism for brace printing. Specifically, each unit is connected to the control module through a drive device, and its height and inclination are adjusted up and down in real time during the printing process. At the same time, the hot bed unit is controlled by optimizing the support algorithm to provide intelligent support during the object printing process to avoid excessive support of the bottom surface. The dynamic support principle of this system is as follows: the control module analyzes the 3D printing model data based on the existing adaptive slicing algorithm, uses normal vector analysis to calculate the angle θ between each triangular facet of the model and the Z axis, and sets a critical angle of 55°. When the critical angle θ is less than 55°, it is marked as a potential overhang area. The support necessity of potential overhang areas is evaluated, and the projection path of each overhang area along the gravity direction is calculated. If there is a 3D model structure in the projection path, it is marked as a self-supporting area. A support demand heat map is generated for the remaining areas that cannot be self-supported. Based on the support demand heat map, a grid matrix of hot bed units is established, and the responsible area of each hot bed unit is determined. The G code for controlling the movement of each lead screw is converted using the existing slicing software. The slicing data is converted into the hot bed unit lifting instruction parameters using the existing kinematic inverse solution algorithm. The control module then controls the drive device to start, and the drive gear on the drive shaft drives the transmission gear to rotate. The rotation of the transmission gear drives the lead screw in the corresponding area, raising the target hot bed unit platform to the working height of the nozzle. The remaining inactivated hot bed unit platforms remain in a sunken state. The fixed plate moves to the working position driven by the existing moving mechanism via the movable guide rod to provide support for the printing base surface. When printing overhanging structures, the drive unit precisely lifts the designated hot bed unit platform to the height of the support surface through the transmission of the meshing drive gear and transmission gear and the lead screw. Multiple sets of cameras are used in combination with the existing visual space positioning algorithm to verify the accuracy of the hot bed unit platform. At the same time, the inclination angle of the hot bed unit platform is adjusted through the differential motion of the multiple lead screws to achieve adaptive fit with the overhanging surface. Only the support structure with minimized (lightweight) contact with the bottom surface of the model is generated above the raised hot bed unit platform. The inactivated units remain stationary to reduce the system load, thereby significantly reducing the consumption of redundant support materials, reducing printing costs, and avoiding the interference problem of traditional global support on the model surface. In addition, multiple sets of cameras are used to monitor the flatness of each unit of the hot bed unit platform in real time. When local warping or decline is detected, compensation instructions are generated through the control module, allowing the drive unit to fine-tune the rotation angle of the corresponding lead screw according to the compensation instruction. The height correction of the hot bed unit platform is achieved through the meshing drive gear and transmission gear transmission.In summary, the present application can intelligently determine which areas need support, provide appropriate support by adjusting the hot bed unit, reduce the support area on the bottom surface of the model, thereby reducing the use of support materials and optimizing the printing quality. At the same time, based on the control of the independent drive device, the height correction of the hot bed unit platform can be realized, effectively eliminating the platform offset caused by mechanical deformation or assembly error, ensuring the consistency of the printing layer thickness, and improving the forming accuracy of the formed part.

[0008] Further, a rotary magnetic encoder is built in the drive device.

[0009] Further, the drive device is a drive motor.

[0010] Further, the end of the drive shaft of the drive device penetrates through the first fixing plate and is movably arranged in the second fixing plate.

[0011] Further, two relatively arranged support plates are fixedly connected to the bottom surface of the second fixing plate, and the two moving guide rods are respectively fixedly sleeved on the two support plates. Description of the Drawings

[0012] Figure 1 is the first side view structural schematic diagram of the intelligent hot bed system of the fused deposition modeling 3D printer provided by the present invention.

[0013] Figure 2 is the second side view structural schematic diagram of the intelligent hot bed system of the fused deposition modeling 3D printer provided by the present invention.

[0014] Figure 3 is the top view structural schematic diagram of the intelligent hot bed system of the fused deposition modeling 3D printer provided by the present invention.

[0015] Figure 4 is Figure 3 the cross-sectional structural schematic diagram in the A-A direction in

[0016] In the figure, 1, the first fixing plate; 2, the second fixing plate; 3, the transmission gear; 4, the lead screw; 5, the hot bed unit platform; 6, the drive device; 61, the drive shaft; 7, the drive gear; 8, the moving guide rod; 9, the support plate. Detailed Embodiments

[0017] In order to make the technical means, creative features, achieved purposes and effects of the present invention easy to understand, the present invention will be further described below with reference to specific drawings.

[0018] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "longitudinal", "radial", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is 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. Therefore, it should not be construed as a limitation to the present invention. In the description of the present invention, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0019] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "mounted", "connected" and "coupled" shall be construed broadly. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0020] Please refer to Figures 1 to 4As shown in the figure, the present invention provides an intelligent hot bed system for a fused deposition modeling 3D printer, which includes a first fixed plate 1 and a second fixed plate 2 arranged oppositely. A plurality of gear seats (not shown in the figure) are fixedly connected between the first fixed plate 1 and the second fixed plate 2. A driving gear 3 is rotatably installed in the gear cavity of each gear seat. A notch is formed on the side surface of the gear seat, and a part of the driving gear 3 exposes from the notch. A lead screw 4 passing through the first fixed plate 1 and the second fixed plate 2 is threadedly connected in the central hole of the driving gear 3. The top of the lead screw 4 passing through the first fixed plate 1 is hinged to the hot bed unit platform 5 through a universal joint, that is, the hot bed unit platform 5 is movably connected to the top of the lead screw 4 through an existing universal joint. A plurality of groups of cameras (not shown in the figure) installed on an existing 3D printer are arranged above the hot bed unit platform 5. A driving device 6 is fixedly connected to the surface of the first fixed plate 1 near the lead screw 4. All the plurality of groups of cameras and the driving devices 6 on the surface of the first fixed plate 1 are electrically connected to a control module (not shown in the figure). The control module can be specifically implemented by using an existing programmable logic controller or a single-chip microcomputer. The driving shaft of the driving device 6 passes through the first fixed plate 1 to the second fixed plate 2, that is, the driving shaft 61 of the driving device 6 stops on the second fixed plate 2 after passing through the first fixed plate 1. A driving gear 7 is fixedly sleeved on the driving shaft 61 between the first fixed plate 1 and the second fixed plate 2. The driving gear 7 meshes with the driving gear 3 exposing from the notch. Thus, after the driving device 6 is started, the driving gear 7 and the driving gear 3 that mesh with each other can be driven to rotate through the driving shaft 61, and then the lead screw 4 and the hot bed unit platform 5 can be driven to lift through the rotating driving gear 3. Two moving guide rods 8 arranged oppositely are fixedly connected to the bottom surface of the second fixed plate 2. One end of the moving guide rod 8 is cooperatively connected with an existing moving mechanism on the 3D printer. Specifically, the moving guide rod 8 can be set as a threaded guide rod. A rotating gear is arranged on the existing moving mechanism. The central hole of the rotating gear is in threaded fit with the threaded guide rod. When the rotating gear rotates, the fixed plate can be driven to move to the working position through the moving guide rod 8.

[0021] Compared with the existing technology, the intelligent hot bed system of the fused deposition modeling 3D printer provided by the present invention is composed of multiple movable hot bed unit platforms. The hot bed unit platforms adopt an independent modular layout. Each hot bed unit platform is hinged to the lead screw through a universal joint. It can be independently raised and lowered and coordinated. It can be dynamically adjusted according to the shape of the printed object, support requirements and printing stage requirements. Specifically, each unit is connected to the control module through a drive device, and its height and inclination are adjusted up and down in real time during the printing process. At the same time, the hot bed unit is controlled by optimizing the support algorithm to provide intelligent support during the printing process of the object to avoid excessive support of the bottom surface. The dynamic support principle of this system is as follows: the control module analyzes the 3D printing model data based on the existing adaptive slicing algorithm, uses normal vector analysis to calculate the angle θ between each triangular facet of the model and the Z axis, and sets a critical angle of 55°. When the critical angle θ is less than 55°, it is marked as a potential overhang area. The support necessity of potential overhang areas is evaluated, and the projection path of each overhang area along the gravity direction is calculated. If there is a 3D model structure in the projection path, it is marked as a self-supporting area. A support demand heat map is generated for the remaining areas that cannot be self-supported. Based on the support demand heat map, a grid matrix of hot bed units is established, and the responsible area of each hot bed unit is determined. The G code for controlling the movement of each lead screw is converted using the existing slicing software. The slicing data is converted into the hot bed unit lifting instruction parameters using the existing kinematic inverse solution algorithm. The control module then controls the drive device to start, and the drive gear on the drive shaft drives the transmission gear to rotate. The rotation of the transmission gear drives the lead screw in the corresponding area, raising the target hot bed unit platform to the working height of the nozzle. The remaining inactivated hot bed unit platforms remain in a sunken state. The fixed plate moves to the working position driven by the existing moving mechanism via the movable guide rod to provide support for the printing base surface. When printing overhanging structures, the drive unit precisely lifts the designated hot bed unit platform to the height of the support surface through the transmission of the meshing drive gear and transmission gear and the lead screw. Multiple sets of cameras are used in combination with the existing visual space positioning algorithm to verify the accuracy of the hot bed unit platform. At the same time, the inclination angle of the hot bed unit platform is adjusted through the differential motion of the multiple lead screws to achieve adaptive fit with the overhanging surface. Only the support structure with minimized (lightweight) contact with the bottom surface of the model is generated above the raised hot bed unit platform. The inactivated units remain stationary to reduce the system load, thereby significantly reducing the consumption of redundant support materials, reducing printing costs, and avoiding the interference problem of traditional global support on the model surface. In addition, multiple sets of cameras are used to monitor the flatness of each unit of the hot bed unit platform in real time. When local warping or decline is detected, compensation instructions are generated through the control module, allowing the drive unit to fine-tune the rotation angle of the corresponding lead screw according to the compensation instruction. The height correction of the hot bed unit platform is achieved through the meshing drive gear and transmission gear transmission.In summary, the present application can intelligently determine which areas need support, provide appropriate support by adjusting the hot bed unit, reduce the support area on the bottom surface of the model, thereby reducing the use of support materials and optimizing the printing quality. At the same time, based on the control of the independent driving device, the height correction of the hot bed unit platform can be realized, effectively eliminating the platform offset caused by mechanical deformation or assembly error, ensuring the consistency of the printing layer thickness, and improving the forming accuracy of the formed part.

[0022] As a specific embodiment, a rotary magnetic encoder is built in the driving device 6. The rotary magnetic encoder is used to detect the rotation phase of the driving lead screw in real time and dynamically calibrate it in combination with the existing least squares plane fitting algorithm, so as to drive all the hot bed unit platforms 5 to reset to the reference plane in the vertical direction, ensuring that the initial heights of all the hot bed units are the same. Among them, the rotation phase detection principle of the rotary magnetic encoder is realized by detecting the magnetic field change on the magnetic encoding disk through a magnetic sensor. A magnetic encoder usually consists of a magnetic encoding disk with a specific magnetic pattern and a magnetic sensor. When the magnetic encoding disk rotates, the magnetic sensor will detect the magnetic field change and output corresponding electrical signals. The phase difference of these signals can be used to judge the angle change of the rotation. Its specific structure and working principle are well-known prior arts to those skilled in the art.

[0023] As a specific embodiment, the driving device 6 is a driving motor, which can provide driving force for the rotation of the driving gear 7 and the transmission gear 3, and then drive the hot bed unit platform 5 to lift or lower through the lead screw 4.

[0024] As a specific embodiment, please refer to Figure 4 As shown, the end of the driving shaft 61 of the driving device 6 penetrates through the first fixing plate 1 and is movably arranged in the second fixing plate 2, which can make the rotation of the driving shaft 61 more stable and drive the hot bed unit platform 5 to lift or lower smoothly.

[0025] As a specific embodiment, please refer to Figure 2 As shown, two relatively arranged support plates 9 are fixedly connected to the bottom surface of the second fixing plate 2, and the two moving guide rods 8 are respectively fixedly sleeved on the two support plates 9. Thus, when the moving guide rods 8 move driven by the rotation of the rotating gear of the existing moving mechanism, the fixing plate can be driven to move smoothly through the moving guide rods 8.

[0026] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the purpose and scope of the technical solutions of the present invention, and they should all be covered by the scope of the claims of the present invention.

Claims

1. An intelligent heated bed system for a fused deposition modeling 3D printer, characterized in that, It includes a first fixed plate and a second fixed plate which are relatively arranged. A plurality of gear seats are fixedly connected between the first fixed plate and the second fixed plate. A transmission gear is rotatably installed in the gear cavity of each gear seat. A notch is formed on the side surface of the gear seat, and a part of the transmission gear protrudes from the notch. A lead screw passing through the first fixed plate and the second fixed plate is threadedly connected in the central hole of the transmission gear. The top of the lead screw passing through the first fixed plate is hinged to a hot bed unit platform through a universal joint. Above the hot bed unit platform, a plurality of groups of cameras installed on the 3D printer are provided. A driving device is fixedly connected to the surface of the first fixed plate near the lead screw. All the plurality of groups of cameras and the driving devices on the surface of the first fixed plate are electrically connected to a control module. The driving shaft of the driving device passes through the first fixed plate to the second fixed plate. A driving gear is fixedly sleeved on the driving shaft between the first fixed plate and the second fixed plate. The driving gear meshes with the transmission gear protruding from the notch. Two relatively arranged moving guide rods are fixedly connected to the bottom surface of the second fixed plate. One end of the moving guide rod is cooperatively connected with an existing moving mechanism on the 3D printer.

2. The intelligent hot bed system of the fused deposition modeling 3D printer according to claim 1, characterized in that, The driving device is internally provided with a rotary magnetic encoder.

3. The intelligent hot bed system of the fused deposition modeling 3D printer according to claim 1, wherein The driving device is a driving motor.

4. The intelligent hot bed system of the fused deposition modeling 3D printer according to claim 1, characterized in that The end of the driving shaft of the driving device passes through the first fixed plate and is movably arranged in the second fixed plate.

5. The intelligent hot bed system of the fused deposition modeling 3D printer according to claim 1, characterized in that, Two relatively arranged support plates are fixedly connected to the bottom surface of the second fixed plate. The two moving guide rods are respectively fixedly sleeved on the two support plates.

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