A multi-degree of freedom machining device for 3D printed support structure removal

Abstract

This invention discloses a multi-degree-of-freedom machining device for removing support structures in 3D printing, relating to the technical field of post-processing in metal additive manufacturing. This invention aims to solve the problems of low operational precision and easy damage to parts in existing 3D printing support removal methods. The invention includes a mounting base, a rotary drive assembly, a tool feed assembly, and a dust removal assembly. An inner bushing is fixedly connected to the extended end of a hollow driven shaft. An outer bushing is fitted outside the inner bushing. A linear feed motor that drives the cutting tool axially feeds is located inside the inner bushing. The outer bushing can slide axially relative to the inner bushing and is driven to rotate synchronously by the inner bushing. The dust removal assembly includes a dust suction port on the outer bushing, an internal gas flow channel inside the inner bushing, a telescopic conduit connecting the two, a dust collection chamber, and a negative pressure source. The gas flow channel is connected to the dust collection chamber via the hollow driven shaft. This invention, through multi-degree-of-freedom posture adjustment of the robotic arm combined with independent tool feed, can complete the support removal of complex parts in one operation, eliminating the need for multiple clamping operations.

Description

Technical Field

[0001] This invention relates to the technical field of post-processing in metal additive manufacturing, specifically a multi-degree-of-freedom processing device for removing support structures from 3D printed materials. Background Technology

[0002] Existing 3D printed parts, especially metal 3D printed parts or complex structural parts, often require the removal of support structures after printing. Traditional methods include manual hammering, breaking with pliers, or grinding with a hand drill. While this method is flexible, the precision relies entirely on manual experience, which can easily damage the surface of the printed part. Furthermore, tools are difficult to reach support points inside deep cavities, limiting the operator's field of vision.

[0003] One proposed solution utilizes an industrial robot carrying a spindle or cutting tool for support removal. Robots possess multiple degrees of freedom, enabling flexible posture adjustment. However, existing robotic support removal devices suffer from the following shortcomings: most solutions rigidly fix the cutting tool to the robot's end effector, relying solely on the robot's overall motion for cutting feed. This method struggles to achieve high-precision, small-range micro-feeding, especially when removing small supports or fine-tuning support residues, making control difficult and prone to overcutting.

[0004] The support removal process generates a large amount of dust (such as metal powder and plastic debris). An external, independent dust collection pipe is used, but this pipe gets tangled and dragged along with the robot's movement, affecting its flexibility. Furthermore, the dust suction port is fixed in position and difficult to move with the cutting point, resulting in poor dust removal efficiency. Therefore, a support removal device specifically designed for 3D printed parts, capable of flexibly entering complex areas, is needed. Summary of the Invention

[0005] To address the aforementioned problems, namely the issues raised in the background section, this invention proposes a multi-degree-of-freedom processing device for removing support structures from 3D printing, comprising a robotic arm with a processing main body mechanism mounted at the end of the robotic arm. The main processing mechanism includes a mounting base, inside which a rotary drive assembly is provided. The output end of the rotary drive assembly is connected to a hollow driven shaft, which passes through and extends out of the mounting base. An inner bushing is fixedly connected to the extended end of the hollow driven shaft. An outer bushing is fitted around the inner bushing. A linear feed motor is installed inside the inner bushing. A cutting tool is installed at the output end of the linear feed motor. The linear feed motor drives the cutting tool to feed axially relative to the inner bushing. The inner bushing and the outer bushing are slidably engaged by a guide slider and a guide groove, allowing the outer bushing to slide axially relative to the inner bushing. At the same time, the inner bushing drives the outer bushing to rotate synchronously through the guide slider and the guide groove. The main processing mechanism is also equipped with a dust removal component, which includes several dust suction ports opened on the outer bushing, an internal gas flow channel disposed inside the inner bushing, a telescopic conduit connecting the dust suction ports and the internal gas flow channel, and a dust collection chamber disposed inside the mounting base. The internal gas flow channel passes through the hollow driven shaft and connects to the dust collection chamber, and the dust collection chamber is connected to a negative pressure source. A further feature of the present invention is that the hollow driven shaft has a hollow structure, and the internal gas flow channel passes through the hollow structure and communicates with the dust collection chamber.

[0006] A further feature of the present invention is that a conductive slip ring is provided at the tail end of the hollow driven shaft, one end of the conductive slip ring is connected to an external controller and a power supply, and the other end is connected to the control line and power supply line of the linear feed motor.

[0007] A further feature of the present invention is that the robotic arm is a six-axis industrial robot.

[0008] A further configuration of the present invention is as follows: the rotary drive assembly includes a rotary drive motor, the output end of the rotary drive motor is connected to a drive shaft, and the drive shaft is connected to the hollow driven shaft via a sprocket and a chain.

[0009] A further configuration of the present invention is that the guide slider is disposed on the outer wall of the inner bushing, and the guide groove is disposed on the inner wall of the outer bushing.

[0010] A further provision of the present invention is that the telescopic conduit maintains continuous communication between the dust suction port and the internal gas flow channel when the inner bushing extends or retracts axially relative to the outer bushing.

[0011] A further feature of the present invention is that a filter assembly and a sealing cover are provided inside the dust collection chamber, and the sealing cover and the dust collection chamber are hinged or detachably connected.

[0012] A further provision of the present invention is that the cutting tool is one of a drill bit, a milling cutter, or a grinding head.

[0013] A further configuration of the present invention is that the rotary drive motor, the linear feed motor, and the negative pressure source are all electrically connected to a controller.

[0014] The beneficial technical effects of this invention are as follows: it achieves independent axial feed of the cutting tool, significantly improving the accuracy and flexibility of support removal. This invention integrates a linear feed motor inside the inner bushing, directly driving the cutting tool to feed axially relative to the inner bushing. This decouples the tool's rotational motion from the axial feed motion, eliminating the need to rely on the overall robot motion for feed. Compared to existing solutions, this invention can achieve micron-level precision feed, making it particularly suitable for pinpoint removal of small supports and fine finishing of support residues, effectively avoiding over-cutting or under-cutting problems caused by robot positioning errors.

[0015] This invention achieves dust collection during rotation and sliding, significantly improving the working environment. A dust suction port is opened on the outer bushing, connected to the internal gas flow channel inside the inner bushing via a telescopic conduit. The gas is then led to the dust collection chamber via the hollow driven shaft and connected to a negative pressure source. The dust suction port rotates and slides axially synchronously with the outer bushing, always aligning with the contact area between the cutting tool and the workpiece, achieving the effect of "cutting while suctioning dust." Simultaneously, the telescopic conduit remains continuously open when the outer bushing slides axially relative to the inner bushing. The gas flow channel is built into the inner bushing and the hollow driven shaft, eliminating the need for external piping and avoiding pipe entanglement and dragging problems, resulting in high dust capture efficiency.

[0016] This invention improves support removal efficiency by utilizing the multi-degree-of-freedom posture adjustment of a robotic arm, combined with the independent rotation and feed of the cutting tool. It enables the removal of all support structures on complex parts in a single operation, eliminating the need for multiple clamping operations or manual intervention. Furthermore, the integrated dust removal function reduces subsequent cleaning steps, significantly enhancing the automation level and overall efficiency of support removal.

[0017] This invention effectively protects the surface quality of parts. By using a linear feed motor to achieve precise force and position control, and in conjunction with a robot compliant control strategy, it can remove supports with lower cutting force, avoiding damage or deformation of the part surface due to rigid impact. It is especially suitable for the post-processing of supports for thin-walled parts and delicate structural parts. Attached Figure Description

[0018] Figure 1 A schematic diagram of the structure of the present invention is shown.

[0019] Figure 2 A schematic diagram of the internal structure of the mounting base is shown.

[0020] Figure 3 A schematic diagram of the internal gas flow channel structure is shown.

[0021] Figure 4 A schematic diagram of the telescopic conduit structure is shown.

[0022] Reference numerals: 1. Robotic arm, 2. Mounting base, 3. Hollow driven shaft, 4. Inner bushing, 5. Outer bushing, 6. Linear feed motor, 7. Cutting tool, 8. Guide slider, 9. Guide groove, 10. Dust suction port, 11. Internal gas flow channel, 12. Telescopic duct, 13. Dust collection chamber, 14. Negative pressure source, 15. Filter assembly, 16. Sealing cover, 17. Rotary drive motor, 18. Drive shaft. Detailed Implementation

[0023] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0024] like Figures 1 to 4 As shown, this embodiment provides a multi-degree-of-freedom processing device for removing support structures from 3D printed parts, including a robotic arm 1, with a processing main body mechanism mounted at the end of the robotic arm 1. The robotic arm 1 is preferably a six-axis industrial robot, capable of flexible posture adjustment in six degrees of freedom in space, facilitating access to the inner cavities, recesses, and other areas of complex parts for support removal operations. The processing main body mechanism is fixedly connected to the end flange of the robotic arm 1 via a mounting base 2.

[0025] The mounting base 2 is internally equipped with a rotary drive assembly. Specifically, the rotary drive assembly includes a rotary drive motor 17, the output end of which is connected to a drive shaft 18. The drive shaft 18 is connected to a hollow driven shaft 3 via a sprocket and a chain. The hollow driven shaft 3 passes through and extends out of the mounting base 2.

[0026] Through this rotary drive assembly, the power of the rotary drive motor 17 is transmitted to the hollow driven shaft 3 via the drive shaft 18, sprocket, and chain, driving the hollow driven shaft 3 to rotate around its axis. The sprocket and chain drive method has the advantages of smooth transmission and high load-bearing capacity, and can adapt to the intermittent cutting impact during the support removal process.

[0027] An inner bushing 4 is fixedly connected to the extended end of the hollow driven shaft 3. An outer bushing 5 is fitted around the inner bushing 4. A linear feed motor 6 is installed inside the inner bushing 4, and a cutting tool 7 is installed at the output end of the linear feed motor 6. The cutting tool 7 can be selected from a drill bit, a milling cutter, or a grinding head, depending on the support material and structural form.

[0028] The linear feed motor 6 drives the cutting tool 7 to feed axially relative to the inner bushing 4. This structure decouples the rotational motion of the tool (transmitted by the rotary drive assembly via the hollow driven shaft and inner bushing) from the axial feed motion (independently controlled by the linear feed motor), eliminating the need to rely on the overall robot motion for feed. Compared to existing technologies, this invention achieves micron-level precision feed, making it particularly suitable for pinpoint removal of small supports and fine finishing of support residues, effectively avoiding overcutting or undercutting problems caused by robot body positioning errors.

[0029] The inner bushing 4 and the outer bushing 5 are slidably engaged by a guide slider 8 and a guide groove 9. Specifically, the guide slider 8 is disposed on the outer wall of the inner bushing 4, and the guide groove 9 is disposed on the inner wall of the outer bushing 5. This engagement structure allows the outer bushing 5 to slide axially relative to the inner bushing 4, while the inner bushing 4 drives the outer bushing 5 to rotate synchronously via the guide slider 8 and the guide groove 9.

[0030] The inner and outer bushings adopt a nested sliding fit structure, making full use of the internal space. The overall device is small in size and has a reasonable center of gravity distribution, making it suitable for installation at the end effector of a six-axis industrial robot without adding extra motion burden to the robot, and it is not prone to interference with the workpiece or environment during multi-pose machining.

[0031] The main processing mechanism is also equipped with a dust removal component. The dust removal component includes a plurality of dust suction ports 10 opened on the outer bushing 5, an internal gas flow channel 11 disposed inside the inner bushing 4, a telescopic conduit 12 connecting the dust suction ports 10 and the internal gas flow channel 11, and a dust collection chamber 13 disposed inside the mounting base 2.

[0032] The internal gas flow channel 11 passes through the hollow structure of the hollow driven shaft 3 and connects to the dust collection chamber 13. The dust collection chamber 13 is connected to a negative pressure source 14. The dust collection chamber 13 is also equipped with a filter assembly 15 and a sealing cover plate 16. The sealing cover plate 16 is hinged or detachably connected to the dust collection chamber 13 to facilitate regular cleaning of the collected dust.

[0033] The telescopic conduit 12 maintains continuous communication between the dust suction port 10 and the internal gas flow channel 11 when the outer bushing 5 extends or retracts axially relative to the inner bushing 4. The telescopic conduit 12 may adopt a corrugated pipe or a sleeve-type telescopic structure.

[0034] In addition, to prevent dust from entering the sliding mating surface, a dustproof sealing structure (such as a lip seal ring) may be provided between the inner bushing 4 and the outer bushing 5 at the end near the cutting tool 7.

[0035] This dust removal path has the following advantages: (1) The dust suction port 10 rotates and slides axially synchronously with the outer bushing 5, always aligning with the contact area between the cutting tool 7 and the workpiece, realizing "cutting while suctioning dust", with high dust capture efficiency; (2) The telescopic conduit 12 remains continuously conductive when the outer bushing 5 slides axially relative to the inner bushing 4, adapting to the dynamic working state of the device; (3) The gas flow channel is built into the inner bushing 4 and the hollow driven shaft 3, without external pipelines, thus avoiding the problems of pipe entanglement and dragging.

[0036] A conductive slip ring (not shown in the figure) is provided at the tail end of the hollow driven shaft 3. One end of the conductive slip ring is connected to an external controller and power supply, and the other end is connected to the control line and power line of the linear feed motor 6. The cable of the linear feed motor 6 is led out through the interior of the hollow driven shaft 3 to the conductive slip ring.

[0037] The motor cable does not become entangled as the hollow driven shaft 3 rotates, and the hollow structure also provides a path for the gas flow channel, realizing "one line and one gas" coaxial transmission, which improves the reliability and service life of the system.

[0038] The rotary drive motor 17, the linear feed motor 6, and the negative pressure source 14 are all electrically connected to a controller. The controller can be a PLC, an embedded controller, or an industrial computer, used to coordinate the movement of the robotic arm 1, the start / stop and speed adjustment of the rotary drive motor 17, the feed speed and position of the linear feed motor 6, and the start / stop of the negative pressure source 14. In terms of specific control strategies, robot compliant control technology can be combined to remove supports with lower cutting forces, avoiding surface damage or deformation of parts caused by rigid impacts.

[0039] By adjusting the robotic arm's multi-degree-of-freedom posture and combining it with the independent rotation and feed of the cutting tool, all support structures on complex parts (such as 3D printed parts with internal cavities, side recesses, or suspended structures) can be removed in one operation without multiple clamping or manual intervention. Simultaneously, the integrated dust removal function reduces subsequent cleaning processes, significantly improving the automation level and overall efficiency of support removal. Combined with precise force / position control, it can also effectively protect the surface quality of thin-walled and delicate structural parts.

[0040] The working process of this device is as follows: First, the controller drives the robotic arm 1 to move, moving the main processing mechanism above the 3D printed part whose support structure needs to be removed, and aligning the cutting tool 7 with the target support area.

[0041] Then, the rotary drive motor 17 is started, which drives the hollow driven shaft 3 to rotate through the drive shaft 18, sprocket, and chain, thereby driving the inner bushing 4 and the outer bushing 5 to rotate synchronously, and the cutting tool 7 rotates at high speed accordingly.

[0042] Next, the linear feed motor 6 is started, driving the cutting tool 7 to feed axially relative to the inner bushing 4 to cut and remove the support structure. During this process, the feed speed and feed rate can be adjusted in real time as needed to achieve precise control.

[0043] Simultaneously, the negative pressure source 14 is activated, creating negative pressure within the dust collection chamber 13. Dust generated during cutting is drawn in through the suction port 10 on the outer bushing 5, enters the internal gas flow channel 11 inside the inner bushing 4 through the telescopic conduit 12, and then enters the dust collection chamber 13 through the hollow structure of the hollow driven shaft 3. After being filtered by the filter assembly 15, clean gas is discharged, and the dust is collected within the dust collection chamber 13.

[0044] When the cutting posture needs to be changed, the robotic arm 1 drives the entire machining body to adjust the angle. Since the dust suction port 10 always rotates with the outer bushing 5 and is close to the cutting point, the dust removal effect is not affected by the posture change.

[0045] After processing is completed, turn off all motors and negative pressure sources, open the sealing cover 16 and clean the dust in the dust collection chamber 13.

[0046] Although the invention has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of the invention. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. The invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0047] In the description of this invention, terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," which indicate direction or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. These are used merely for ease of description and do not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0048] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0049] The term "comprising" or any other similar term is intended to cover non-exclusive inclusion, such that a process, article, or apparatus / device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to those processes, articles, or apparatus / devices.

[0050] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A multi-degree-of-freedom processing device for removing support structures from 3D printing, characterized in that, It includes a robotic arm (1), and a processing main body mechanism is installed at the end of the robotic arm (1); The main processing mechanism includes a mounting base (2), and a rotary drive assembly is provided inside the mounting base (2). The output end of the rotary drive assembly is connected to a hollow driven shaft (3), which passes through and extends out of the mounting base (2). An inner bushing (4) is fixedly connected to the extended end of the hollow driven shaft (3). An outer bushing (5) is fitted outside the inner bushing (4). A linear feed motor (6) is installed inside the inner bushing (4). A cutting tool (7) is installed at the output end of the linear feed motor (6). The linear feed motor (6) drives the cutting tool (7) to feed axially relative to the inner bushing (4). The inner bushing (4) and the outer bushing (5) are slidably engaged by a guide slider (8) and a guide groove (9), so that the outer bushing (5) can slide axially relative to the inner bushing (4), while the inner bushing (4) drives the outer bushing (5) to rotate synchronously through the guide slider (8) and the guide groove (9). The main processing mechanism is also provided with a dust removal component, which includes a plurality of dust suction ports (10) opened on the outer bushing (5), an internal gas flow channel (11) disposed inside the inner bushing (4), a telescopic conduit (12) connecting the dust suction ports (10) and the internal gas flow channel (11), and a dust collection chamber (13) disposed inside the mounting base (2). The internal gas flow channel (11) passes through the hollow driven shaft (3) and connects to the dust collection chamber (13). The dust collection chamber (13) is connected to a negative pressure source (14).

2. The multi-degree-of-freedom processing device for removing support structures in 3D printing according to claim 1, characterized in that, The hollow driven shaft (3) has a hollow structure, and the internal gas flow channel (11) passes through the hollow structure and communicates with the dust collection chamber (13).

3. The multi-degree-of-freedom processing device for removing support structures in 3D printing according to claim 1, characterized in that, A conductive slip ring is provided at the tail end of the hollow driven shaft (3). One end of the conductive slip ring is connected to an external controller and power supply, and the other end is connected to the control line and power supply line of the linear feed motor (6).

4. The multi-degree-of-freedom processing device for removing support structures in 3D printing according to claim 1, characterized in that, The robotic arm (1) is a six-axis industrial robot.

5. A multi-degree-of-freedom processing device for removing support structures in 3D printing according to claim 1, characterized in that, The rotary drive assembly includes a rotary drive motor (17), the output end of which is connected to a drive shaft (18), and the drive shaft (18) is connected to the hollow driven shaft (3) via a sprocket and a chain.

6. The multi-degree-of-freedom processing device for removing support structures in 3D printing according to claim 1, characterized in that, The guide slider (8) is disposed on the outer wall of the inner bushing (4), and the guide groove (9) is disposed on the inner wall of the outer bushing (5).

7. A multi-degree-of-freedom processing device for removing support structures in 3D printing according to claim 1, characterized in that, The telescopic conduit (12) maintains continuous communication between the dust inlet (10) and the internal gas flow channel (11) when the inner bushing (4) extends and retracts axially relative to the outer bushing (5).

8. A multi-degree-of-freedom processing device for removing support structures in 3D printing according to claim 1, characterized in that, The dust collection chamber (13) is equipped with a filter assembly (15) and a sealing cover plate (16). The sealing cover plate (16) and the dust collection chamber (13) are hinged or detachable.

9. A multi-degree-of-freedom processing device for removing support structures in 3D printing according to claim 1, characterized in that, The cutting tool (7) is one of a drill bit, a milling cutter or a grinding head.

10. A multi-degree-of-freedom processing device for removing support structures in 3D printing according to claim 5, characterized in that, The rotary drive motor (17), the linear feed motor (6), and the negative pressure source (14) are all electrically connected to a controller.

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