A coupled wire and pellet fused additive manufacturing apparatus and method

Abstract

The present application relates to a coupling filament and granular material fused additive manufacturing device, which is connected to a filament extrusion device, comprising a granular material conveying part, a filament conveying part and a filament extrusion part, the filament conveying part and the filament extrusion device are communicated; the granular material conveying part has a granular material feeding port and a granular material discharging port, the granular material feeding port is communicated with the granular material discharging port through a feeding channel, and the granular material discharging port is connected with the feeding port of the filament extrusion part through a second bearing; the filament conveying part is inserted into the feeding channel, there is a gap between the filament conveying part and the feeding channel, the filament conveying part is arranged opposite to the feeding port of the filament extrusion part, and the granular material conveying part can rotate relative to the filament conveying part. The present application also relates to a coupling filament and granular material fused additive manufacturing method. The device of the present application realizes the separate printing of two kinds of materials of filament and granular material, also realizes the mixed printing of two kinds of materials of filament and granular material, and belongs to the technical field of 3D printing equipment.

Description

Technical Field

[0001] This invention relates to the field of 3D printing equipment technology, specifically to an apparatus and method for coupled filament and granular material melting additive manufacturing. Background Technology

[0002] Particle-feed fused deposition modeling (FDM) 3D printing technology utilizes a screw extruder with particle feed to address the issues of low forming efficiency and slow forming speed, making it a promising and significant field for development. However, this technology is difficult to apply to multi-material and hybrid material printing, exhibiting poor modification capabilities for mixed materials. Furthermore, when using large-diameter printing, the heat source is located at the bottom, hindering heat transfer to the center and resulting in incomplete material melting. Therefore, optimizing the material extrusion structure is crucial for further improving printing efficiency and accuracy.

[0003] Currently, most hybrid and multi-material printing uses dual-nozzle printing, employing two nozzles to supply different materials for simultaneous printing. This design, however, is less efficient due to the additional nozzle requiring control compared to a single-nozzle structure. It also significantly increases the probability of collisions during printing. Furthermore, the time lag caused by the alternating printing of the dual nozzles can lead to adhesion defects between materials, ultimately affecting the overall strength and quality of the finished product. Therefore, there is an urgent need to optimize and modify the extrusion structure based on the single-nozzle design. Summary of the Invention

[0004] To address the technical problems existing in the prior art, the purpose of this invention is to provide a coupled filament and granular material melting additive manufacturing apparatus and method, enabling the separate printing of filament and granular material, as well as the mixed printing of filament and granular material; and to solve the problems of low efficiency and low quality in the prior art of printing multi-material parts, which requires a dual-nozzle structure.

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

[0006] A coupled filament and granule material melt additive manufacturing apparatus is disclosed. The high-efficiency granule material melt additive manufacturing apparatus is connected to a filament extrusion apparatus. It includes a granule material conveying component, a filament conveying component, and a filament extrusion component. One end of the filament conveying component is connected to the outlet of the filament extrusion apparatus. One end of the granule material conveying component has a granule material inlet, and the other end has a granule material outlet. The granule material inlet is connected to the granule material outlet via a feeding channel within the granule material conveying component. The granule material outlet is connected to the inlet of the filament extrusion component via a second bearing. The other end of the filament conveying component is inserted into the feeding channel from the granule material inlet. A gap exists between the outer surface of the filament conveying component and the feeding channel. The other end of the filament conveying component is directly opposite the inlet of the filament extrusion component. The granule material conveying component is rotatable relative to the filament conveying component.

[0007] As a preferred embodiment, the feeding channel within the pellet conveying component is provided with an internal thread, which extends from the pellet inlet to the pellet outlet.

[0008] As a preferred embodiment, the filament conveying component is connected to a temperature control component, which includes a heating element and a temperature sensor. The heating element is in contact with the filament conveying component to heat the filament conveying component, and the temperature sensor is used to detect the temperature of the filament conveying component.

[0009] As a preferred embodiment, the filament extrusion device is connected to a mounting frame, on which a drive component is mounted to drive the granular material conveying component to rotate relative to the filament conveying component.

[0010] As a preferred embodiment, the driving component is a motor, the output shaft of which is connected to a drive gear, and the outer surface of the pellet conveying component is fitted with a driven gear, which meshes with the drive gear for transmission; a first bearing is also installed on the outer surface of the pellet conveying component, the inner ring of the pellet conveying component and the first bearing are fixed, and the outer ring of the first bearing and the mounting frame are fixed.

[0011] As a preferred option, the feed inlet for the granular material has a funnel-shaped structure.

[0012] As a preferred embodiment, the end of the conveying channel of the granular material conveying component has a discharge collection area, which is located between the other end of the filament conveying component and the inlet of the filament extrusion component.

[0013] A method for melt additive manufacturing of coupled filaments and granules, employing a melt additive manufacturing apparatus for coupled filaments and granules, includes the following steps:

[0014] S1: Connect the filament and granule melt additive manufacturing device to the filament extrusion device of the 3D printer;

[0015] S2: Select a test piece made of multiple materials and start the 3D printer to print;

[0016] S3: Adjust the extrusion speed of filament and granules according to the ratio of ordinary materials and reinforcing materials required for the test piece, observe the extrusion of filament and granules, adjust the preset temperature and parameters of the PID heating system for filament and granules extrusion and the movement speed of the extrusion structure to ensure that the material flows out uniformly and the internal and external flow velocities are equal, and obtain the conveying flow rates of filament extrusion and granules extrusion respectively.

[0017] S4: Print multiple test pieces according to steps S2-S3. Before printing each test piece, adjust the PID coefficient, preset temperature and extrusion speed respectively. Observe the printing quality and accuracy of the multiple test pieces, test the mechanical properties and special properties of the printing material, and determine the specific parameters of the temperature control PID internal and external heating control system and the motion coordination relationship between the ideal temperature field and the extrusion structure according to the printing parameter set that meets the usage requirements.

[0018] S5: Based on the obtained conveying flow rates of filament extrusion and granule extrusion, and the stable temperature control of the PID internal and external heating control system, start printing the multi-material reinforced manufacturing parts that need to be printed.

[0019] In summary, the present invention has the following advantages:

[0020] 1. The device of the present invention enables the separate printing of two materials, filament and granules, as well as the mixed printing of the two materials, thus solving the problems of low efficiency and low quality that exist in the prior art for printing multi-material parts, which requires a dual-nozzle structure.

[0021] 2. The device of this invention improves the processing capacity of mixed materials: Due to the high controllability of filamentary wires, traditional filamentary wire printing can achieve higher efficiency and accuracy than granular raw materials when recycling some mixed materials. This invention actively controls the conveying of granular materials or filaments through granular material conveying components and filament conveying components according to different actual needs. By selecting different material transport methods, different materials can be printed according to different material requirements, eliminating the need for a dual-nozzle structure.

[0022] 3. This invention improves multi-material printing capability: Since different materials have different properties, and different properties are suitable for different material transportation methods, this invention provides the option of traditional filament printing on the basis of granular material extrusion printing. Compared with the dual-nozzle structure, the probability of collision during printing is reduced, and it is less affected by the adhesion defects between materials caused by the time difference during printing.

[0023] 4. This invention improves the uniformity of heating during the printing melting process: Since the heating source in the melting process is located at the bottom, the heat transfer from bottom to top is very uneven. The filament conveying component in this invention is connected to a temperature control component, which can act as a heating medium to uniformly apply heat to the material melting process, greatly ensuring the quality and speed of material processing and improving subsequent printing accuracy and efficiency. Attached Figure Description

[0024] Figure 1 This is a half-sectional schematic diagram of a melting additive manufacturing apparatus for coupled filaments and granules.

[0025] Figure 2 An exploded view of an apparatus for melt additive manufacturing of coupled filaments and granules.

[0026] Figure 3 This is a perspective view of an apparatus for melt additive manufacturing of coupled filaments and granules.

[0027] Figure 4 This is a perspective view of a wire extrusion device.

[0028] Figure 5 This is a 3D view of the granular material conveying component.

[0029] Figure 6 This is a half-sectional schematic diagram of the granular material conveying component.

[0030] Figure 7 This is a three-dimensional view of the filament extrusion component.

[0031] Figure 8 A three-dimensional view of the wire conveying component.

[0032] Among them, 1 is the filament extrusion device, 2 is the granular material conveying component, 3 is the filament conveying component, 4 is the filament extrusion component, 5 is the discharge port of the filament extrusion device, 6 is the granular material inlet, 7 is the internal thread, 8 is the discharge collection area, 9 is the inlet of the filament extrusion component, 10 is the motor, 11 is the driving gear, 12 is the driven gear, 13 is the first bearing, 14 is the mounting frame, and 15 is the second bearing. Detailed Implementation

[0033] The present invention will now be described in further detail with reference to specific embodiments.

[0034] like Figure 1-8As shown, this embodiment provides a coupled filament and granule material melt additive manufacturing apparatus. The high-efficiency granule material melt additive manufacturing apparatus is connected to the filament extrusion apparatus 1 and includes a granule material conveying component 2, a filament material conveying component 3, and a filament material extrusion component 4. One end of the filament material conveying component 3 is connected to the discharge port 5 of the filament material extrusion apparatus. One end of the granule material conveying component 2 has a granule material inlet 6, and the other end of the granule material conveying component 2 has a granule material outlet. The granule material inlet 6 is connected to the granule material outlet through a feeding channel inside the granule material conveying component 2. The granule material outlet is connected to the inlet 9 of the filament material extrusion component through a second bearing 15. The other end of the filament material conveying component 3 is inserted into the feeding channel from the granule material inlet 6. There is a gap between the outer surface of the filament material conveying component 3 and the feeding channel. The other end of the filament material conveying component 3 is directly opposite the inlet 9 of the filament material extrusion component. The granule material conveying component 2 can rotate relative to the filament material conveying component 3. In this embodiment, the filament extrusion device 1, the granule conveying component 2, the filament conveying component 3, and the filament extrusion component 4 can all adopt corresponding structures found in existing 3D printers. For example, the filament extrusion component 4 can be the print head of an existing 3D printer, and the filament extrusion device 1, the granule conveying component 2, and the filament conveying component 3 can be the material supply structure of a 3D printer for conveying the corresponding materials. It is only necessary to set both ends of the granule conveying component 2 as open, hollow structures inside, so that the filament conveying component 3 can be accommodated within it. By switching between conveying filament and granules, the individual printing of filament and granules can be achieved, as well as the mixed printing of filament and granules. In this embodiment, since the granules may be blocked by the filament conveying component 3, the granule conveying component 2 is designed to rotate relative to the filament conveying component 3, and a gap is set between the two, so that the granules can be smoothly conveyed.

[0035] like Figure 5-6 As shown, in some embodiments, the feeding channel within the pellet conveying component 2 is provided with an internal thread 7, which extends from the pellet inlet 6 towards the pellet outlet. In this embodiment, considering the large gap between the pellet conveying component 2 and the filament conveying component 3 during relative rotation, and the potential for blockage due to pellet movement within this gap, preventing relative rotation, the internal thread 7 is designed to allow the pellet to move within it, thus avoiding blockage and preventing the pellet conveying component 2 from rotating. Traditional pellet conveying structures use a method where the external screw rotates while the external screw remains stationary. However, the filament conveying component in this solution cannot rotate, otherwise it would severely affect the extrusion of the filament (e.g., breakage due to friction). Therefore, this method achieves relative movement between the pellet and the threaded structure, thereby realizing material conveying.

[0036] In some embodiments, the filament conveying component 3 is connected to a temperature control component, which includes a heating element and a temperature sensor. The heating element is in contact with the filament conveying component 3 to heat it, and the temperature sensor is used to detect the temperature of the filament conveying component 3. By calculating the temperature difference between the data obtained from the temperature sensor and the set temperature field, the heating temperature of the heating block is adjusted by a PID control module. The temperature field is controlled in real time according to the extrusion speed, reducing energy loss and improving the uniformity of the extruded material. The filament conveying component 3 has a heating function, which not only ensures the temperature stability of the internal filament during transport but also better prevents incomplete melting of the granular material on the outside of the filament conveying component 3, resulting in more complete processing of the printing material and higher subsequent printing efficiency and accuracy.

[0037] like Figure 1-3 As shown, in some embodiments, the filament extrusion device 1 is connected to a mounting frame 14, and a drive component is mounted on the mounting frame 14 to drive the granular material conveying component 2 to rotate relative to the filament conveying component 3. In this embodiment, some existing drive structures can be used to achieve the rotation of the granular material conveying component 2 relative to the filament conveying component 3, such as direct motor drive or other structural forms.

[0038] like Figure 1-3 As shown, in some embodiments, the driving component is a motor 10, the output shaft of the motor 10 is connected to a drive gear 11, and a driven gear 12 is fitted on the outer surface of the pellet conveying component 2. The drive gear 11 and the driven gear 12 mesh and drive each other. A first bearing 13 is also installed on the outer surface of the pellet conveying component 2. The inner ring of the pellet conveying component 2 and the first bearing 13 are fixed, and the outer ring of the first bearing 13 is fixed to the mounting frame 14. In this embodiment, which is a preferred specific implementation structure of the above-mentioned driving component, there are two motors. The two motors drive two drive gears respectively, which mesh with the driven gears, thereby driving the pellet conveying component 2 to rotate, facilitating the conveying of pellets in the pellet conveying component 2.

[0039] In some embodiments, the pellet feed inlet 6 has a flared opening structure. In this embodiment, as shown... Figure 5-6 As shown, the granular material conveying component has a cylindrical structure. The vertical cross-section of the granular material inlet 6 at one end is an isosceles trapezoid. The length of the long base of the isosceles trapezoid is greater than the outer diameter of the cylinder, and the length of the short base of the isosceles trapezoid is equal to the outer diameter of the cylinder.

[0040] In some embodiments, the end of the conveying channel of the pellet conveying component 2 has a discharge collection area 8, which is located between the other end of the filament conveying component 3 and the inlet of the filament extrusion component 4. In this embodiment, as... Figure 1As shown, the conveying channel of the granular material conveying component 2 is a truncated cone with a gradually decreasing radius. The conveying channel has the largest radius at the granular material inlet 6 and the smallest radius at the granular material outlet. There is a cylindrical discharge collection area 8 at the granular material outlet. When the granular material is conveyed to the granular material outlet, it first collects here and is then slowly extruded from the filament extrusion component. The filaments conveyed by the filament conveying component are also conveyed from the end to the discharge collection area 8 and then slowly extruded from the filament extrusion component.

[0041] In some embodiments, such as Figure 1 and Figure 8 As shown, the filament conveying component includes a cylindrical section and a frustum section. The cylindrical section is connected to the outlet of the filament extrusion device, and one end of the frustum section is connected to the other end of the cylindrical section. The other end of the frustum section corresponds to the inlet of the filament extrusion component. Of course, in this embodiment, the filament conveying component is simply configured to correspond to the structure of the granular material conveying component. Different filament conveying component structures can be configured accordingly to achieve a smooth combination and efficient filament conveying. The filament conveying component has a smooth exterior and is made of a thermally conductive material, which can receive and conduct heat, and evenly distribute it for melting the internal filamentous wire and the external granular raw materials. Thermally conductive materials include aluminum alloy, copper alloy, chromium-molybdenum steel, stainless steel, etc. The smooth exterior of the filament conveying component is designed to make the filament extrusion more uniform and smooth.

[0042] A method for melt additive manufacturing of coupled filaments and granules, employing a melt additive manufacturing apparatus for coupled filaments and granules, includes the following steps:

[0043] S1: Connect the filament and granule melt additive manufacturing apparatus to the filament extrusion unit 1 of the 3D printer;

[0044] S2: Select a test piece made of multiple materials that requires filament-assisted reinforcement manufacturing, and set the type of reinforcement material and the proportion of reinforcement material in each part according to manufacturing requirements, and start the 3D printer to print;

[0045] S3: Adjust the extrusion speed of filament and granules according to the ratio of ordinary material and reinforcing material required for the test piece, observe the extrusion of filament and granules, adjust the preset temperature and parameters of the PID heating system of filament and granules extrusion and the movement speed of the extrusion structure (screw and extruder) to ensure that the material flows out uniformly and the internal and external flow velocities are equal, and obtain the conveying flow rates of filament extrusion and granules extrusion respectively.

[0046] S4: Print multiple test pieces according to steps S2-S3. Before printing each test piece, adjust the PID coefficient, preset temperature and extrusion speed respectively. Observe the printing quality and accuracy of the multiple test pieces. Test the mechanical properties and special properties of the printing material (such as the properties changed after the addition of reinforcing materials such as electrical conductivity). Based on the optimal printing parameter set that meets the usage requirements (evaluation criteria: printing time, accuracy, strength (in order)), determine the specific parameters of the temperature control PID internal and external heating control system and the motion coordination relationship between the ideal temperature field and the extrusion structure.

[0047] S5: Based on the obtained conveying flow rates of filament extrusion and granule extrusion, and the stable temperature control of the PID internal and external heating control system, start printing the multi-material reinforced manufacturing parts that need to be printed.

[0048] S6 records the obtained optimal printing parameter set into the statistical data set, which can be used as a reference when manufacturing similar reinforced mechanical structures in the future, thereby reducing testing time and iterations, and reducing material waste.

[0049] By integrating the conveying structures of filaments and granules into a single conveying structure, and by incorporating an optimized temperature field (i.e., temperature control component) for the granule melt extrusion into the filament conveying structure, the manufacturing mechanical structure is enhanced by precisely modifying the reinforcing filament material to ensure that the material meets structural strength requirements, thus achieving high-strength multi-material molding. The ordinary filling structure utilizes granule melt extrusion, with large-diameter solid filling based on structural strength requirements, achieving high-efficiency additive manufacturing. The structures of the granule conveying component, the filament conveying component, and the filament extrusion component are all designed using CAD computer-aided design and formed using additive manufacturing technology.

[0050] The volume of reinforcing material required during the manufacturing process is controlled by manufacturing requirements. Furthermore, different structures within a mechanical device (such as surface structures, internal filling structures, load-bearing structures, and structures with special electrical conductivity requirements) will also impose different requirements on the proportion of reinforcing material. To ensure the uniformity of the extruded material, when less reinforcing material is extruded, the extrusion amount of ordinary granules must be compensated accordingly, and vice versa.

[0051] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A coupled wire and granular feedstock fused additive manufacturing apparatus, the high efficiency granular feedstock fused additive manufacturing apparatus coupled to a wire extrusion apparatus, characterized by: It includes a pellet conveying component, a filament conveying component, and a filament extrusion component. One end of the filament conveying component is connected to the outlet of the filament extrusion device. One end of the pellet conveying component has a pellet inlet, and the other end has a pellet outlet. The pellet inlet is connected to the pellet outlet via a feeding channel inside the pellet conveying component. The pellet outlet is connected to the inlet of the filament extrusion component via a second bearing. The other end of the filament conveying component is inserted into the feeding channel from the pellet inlet. There is a gap between the outer surface of the filament conveying component and the feeding channel. The other end of the filament conveying component is directly opposite the inlet of the filament extrusion component. The pellet conveying component can rotate relative to the filament conveying component. The filament conveying component is connected to a temperature control component, which includes a heating element and a temperature sensor. The heating element is in contact with the filament conveying component to heat the filament conveying component, and the temperature sensor is used to detect the temperature of the filament conveying component.

2. The coupled filament and granular material melt additive manufacturing apparatus according to claim 1, characterized in that: The feeding channel inside the pellet conveying component is provided with an internal thread, which extends from the pellet inlet to the pellet outlet.

3. The coupled filament and granular material melt additive manufacturing apparatus according to claim 1, characterized in that: The filament extrusion device is connected to a mounting frame, on which a drive component is mounted to drive the granular material conveying component to rotate relative to the filament conveying component.

4. The coupled filament and granular material melt additive manufacturing apparatus according to claim 3, characterized in that: The driving component is a motor, and the output shaft of the motor is connected to a drive gear. A driven gear is fitted on the outer surface of the granular material conveying component, and the drive gear and the driven gear mesh and transmit power. A first bearing is also installed on the outer surface of the granular material conveying component. The inner ring of the granular material conveying component and the first bearing are fixed, and the outer ring of the first bearing and the mounting frame are fixed.

5. The apparatus for melt additive manufacturing of coupled filaments and granules according to claim 1, characterized in that: The feed inlet for granular materials has a funnel-shaped structure.

6. The coupled filament and granular material melt additive manufacturing apparatus according to claim 1, characterized in that: The end of the conveying channel of the granular material conveying component has a discharge collection area, which is located between the other end of the filament conveying component and the inlet of the filament extrusion component.

7. A method for melt additive manufacturing of coupled filaments and granular materials, characterized in that, The method using the melting additive manufacturing apparatus for coupled filaments and granules as described in any one of claims 1-6 comprises the following steps: S1: Connect the filament and granule melt additive manufacturing device to the filament extrusion device of the 3D printer; S2: Select a test piece made of multiple materials and start the 3D printer to print; S3: Adjust the extrusion speed of filament and granules according to the ratio of ordinary material and reinforcing material required for the test piece, observe the extrusion of filament and granules, adjust the preset temperature and parameters of the PID heating system for filament and granules extrusion and the movement speed of the extrusion structure to ensure that the material flows out uniformly and the internal and external flow velocities are equal, and obtain the conveying flow rates of filament extrusion and granules extrusion respectively. S4: Print multiple test pieces according to steps S2-S3. Before printing each test piece, adjust the PID coefficient, preset temperature and extrusion speed respectively. Observe the printing quality and accuracy of the multiple test pieces, test the mechanical properties and special properties of the printing material, and determine the specific parameters of the temperature control PID internal and external heating control system and the motion coordination relationship between the ideal temperature field and the extrusion structure according to the printing parameter set that meets the usage requirements. S5: Based on the obtained conveying flow rates of filament extrusion and granule extrusion, and the stable temperature control of the PID internal and external heating control system, start printing the multi-material reinforced manufacturing parts that need to be printed.

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