A tiltable printing selective laser melting apparatus and method

Abstract

The present application relates to additive manufacturing technology field, specifically to a kind of selectively laser melting equipment and method of tilting printing, including rack, laser scanning mechanism, powder laying mechanism, feeding mechanism, forming box and tilting printing mechanism;The rack is equipped with forming box with forming cavity in the interior, the laser scanning mechanism is equipped in forming box, the powder laying mechanism is equipped in the bottom surface of forming cavity, and the feeding mechanism and the tilting printing mechanism are respectively equipped with forming cavity intercommunication on the bottom of both sides of forming box;By tilting printing mechanism, it is accurate to rotate specific angle while lifting, i.e. the overhanging angle of support needed to be added can be reduced to 0 °, and layer-by-layer support-free printing is realized;Not only greatly simplify the difficulty of post-processing of parts, but also can print complex geometric body and curved surface shape parts, greatly improve production efficiency and printing quality.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing technology, specifically to a selective laser melting device and method for tilt printing. Background Technology

[0002] Currently, additive manufacturing technology is an advanced manufacturing technology that has developed rapidly in recent years and is widely used in fields such as jewelry, aerospace, and automobile manufacturing. However, existing selective laser melting additive manufacturing equipment usually relies on a forming platform that can only move in the vertical direction. When the overhang angle is less than 45° during the part printing process, support needs to be added. This not only makes the post-processing of parts difficult, but also causes problems such as the inability to print complex geometries and the low quality of parts at specific angles and positions.

[0003] Therefore, the applicant hereby proposes a selective laser melting device and method for tilt printing to solve the aforementioned problems. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a selective laser melting device and method for tilt printing.

[0005] The technical solution of this invention is as follows: This invention provides a selective laser melting device for tilt printing, comprising a frame, a laser scanning mechanism, a powder spreading mechanism, a feeding mechanism, a forming box, and a tilt printing mechanism; the frame is provided with a forming box having an internal forming cavity, the laser scanning mechanism is located on the forming box, the powder spreading mechanism is located on the bottom surface of the forming cavity, and the bottom sides of the forming box are respectively provided with a feeding mechanism and a tilt printing mechanism connected to the forming cavity; The tilting printing mechanism includes a protective cylinder that is narrower at the top and wider at the bottom, a spherical printing platform, and a ball joint drive assembly. The protective cylinder is fixed to one side of the bottom of the forming box and has a rotating cavity that communicates with the forming cavity. The spherical printing platform is movably located in the upper end of the rotating cavity. The ball joint drive assembly is located at the lower end of the rotating cavity and its working end is connected to the ball joint drive assembly on the periphery of the bottom end of the spherical printing platform.

[0006] Furthermore, the ball joint drive assembly includes at least three ball joint drive arms arranged in a ring at equal intervals on the inner circumference of the lower end of the protective cylinder.

[0007] Furthermore, the ball joint drive arm includes a first linear slide module, a transmission arm, a ball socket, and a transmission ball head; the first linear slide module is vertically disposed on the inner circumference of the lower end of the protective cylinder and its working end is rotatably connected to one end of the transmission arm, the other end of the transmission arm is fixedly provided with a ball socket, and the transmission ball head is fixedly disposed on the circumference of the bottom end of the spherical printing platform and is connected to the ball socket in a ball joint transmission.

[0008] Furthermore, the spherical printing platform has a hollow internal periphery and a horizontal mounting plate. The transmission ball head is located on the bottom surface of the mounting plate, and a clearance hole is provided on the bottom periphery of the spherical printing platform corresponding to the transmission ball head for the transmission arm to extend into.

[0009] Furthermore, the laser scanning mechanism includes a laser generator and a galvanometer arranged horizontally on the forming box; the galvanometer is located on the forming box directly above the tilting printing mechanism.

[0010] Furthermore, the powder spreading mechanism includes a second linear slide module, a blade holder, and a scraper; the second linear slide module is laterally disposed on the side of the bottom surface inside the molding cavity, and a blade holder is provided on the working end of the second linear slide module, with a scraper connected to the blade holder.

[0011] Furthermore, the powder spreading mechanism also includes a recycling funnel and a powder recycling box that are connected to the forming cavity; the recycling funnel is located at the bottom of the forming box outside the tilting printing mechanism, and the powder recycling box is located inside the frame and is connected to the recycling funnel. Furthermore, the feeding mechanism includes a feeding cylinder, a piston, and an electric push rod; the feeding cylinder is fixed to one side of the bottom of the forming box, the piston is provided inside the feeding cylinder, and the electric push rod is located at the bottom of the feeding cylinder and its working end is connected to the piston.

[0012] Furthermore, the molding box also includes an air inlet plate, an air outlet plate, an air intake plate, and an air exhaust plate; the air inlet plate and the air intake plate are disposed opposite each other in the molding cavity on both sides of the inclined printing mechanism, and the air outlet plate and the air exhaust plate are disposed opposite each other in the molding cavity on both sides of the feeding mechanism.

[0013] This invention also provides a selective laser melting tilt printing method, which specifically includes the following steps: S1: Seal the molding box and inject inert gas into the molding cavity; S2: Drive the spherical printing platform to rotate back to zero around the X and Y axes via the ball joint drive assembly, and then raise and lower the spherical printing platform along the Z axis until it is parallel to the printing plane; S3: Evenly spread powder material onto the spherical printing platform; S4: Activate the laser scanning system to laser melt the powder material on the spherical printing platform to form the current layer structure; S5: Based on the geometric parameters of the next layer of the printed part, the control system drives the ball joint drive component to rotate the spherical printing platform around the X and Y axes by a specific angle, and then raises and lowers along the Z axis, repeating S3-S4 to complete the unsupported printing process layer by layer. S6: Printing complete.

[0014] The beneficial effects achieved by this invention are as follows: The present invention provides a selective laser melting device and method for tilt printing. By tilting the printing mechanism and rotating it precisely at a specific angle while raising and lowering it, the hanging angle that requires additional support can be reduced to 0°, achieving layer-by-layer supportless printing. This not only greatly simplifies the post-processing of parts, but also enables the printing of complex geometric shapes and curved surfaces, significantly improving production efficiency and printing quality. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0016] Figure 2 This is a schematic diagram of the internal structure of the present invention.

[0017] Figure 3 This is a cross-sectional schematic diagram of the tilting printing mechanism of the present invention.

[0018] Figure 4 yes Figure 3 Enlarged view of point A.

[0019] Figure 5 yes Figure 3 Enlarged view of point B.

[0020] Figure 6 This is a schematic diagram of the laser scanning mechanism of the present invention.

[0021] Figure 7 This is a schematic diagram of the powder spreading mechanism of the present invention.

[0022] Figure 8 This is a schematic diagram of the feeding mechanism of the present invention.

[0023] Figure 9 This is a schematic diagram of the assembly of the spherical printing platform and the rotating cavity.

[0024] Figure 10 yes Figure 9 Enlarged view of point C.

[0025] Figure 11 This is a schematic diagram of the method flow of the present invention. Detailed Implementation

[0026] To facilitate understanding of the present invention by those skilled in the art, specific embodiments of the present invention are clearly described below with reference to the accompanying drawings. Obviously, the specific embodiments described are merely preferred embodiments of the present invention, and not all embodiments.

[0027] like Figure 1-7As shown, the present invention provides a selective laser melting device for tilt printing, which enables supportless printing of parts and simplifies post-processing of parts; it includes a frame 1, a laser scanning mechanism 2 for selectively melting powder material, a powder spreading mechanism 3 for uniformly spreading powder material, a feeding mechanism 4 for supplying powder material, a forming box 5 for accommodating and protecting the printed parts, and a tilt printing mechanism 6 for supporting and adjusting the printing angle of the parts; the frame 1 is provided with a forming box 5 having an internal forming cavity 51, the laser scanning mechanism 2 is provided on the forming box 5, the powder spreading mechanism 3 is provided on the bottom surface of the forming cavity 51, and the bottom sides of the forming box 5 are respectively provided with a feeding mechanism 4 and a tilt printing mechanism 6 connected to the forming cavity 51; The tilting printing mechanism 6 includes a protective cylinder 61 (narrower at the top and wider at the bottom), a spherical printing platform 62, and a ball joint drive assembly 63. The protective cylinder 61 is fixed to one side of the bottom of the forming box 5, and has a rotating cavity 611 connected to the forming cavity 51. The spherical printing platform 62 is movably disposed in the upper end of the rotating cavity 611. The ball joint drive assembly 63 is disposed at the lower end of the rotating cavity 611, and its working end is connected to the ball joint drive assembly on the periphery of the bottom end of the spherical printing platform 62. The ball joint drive assembly enables precise control of the dynamic tilting capability of the spherical printing platform with multiple degrees of freedom, improving the unsupported printing quality of conventional parts and irregularly shaped parts (such as curved inner cavities and overhanging structures). The control system ensures high-precision displacement of the spherical printing platform in Z-axis lifting and X / Y-axis rotation, effectively avoiding interlayer misalignment caused by the tilting of the spherical printing platform, and ensuring the forming accuracy of complex parts (such as hollow structures).

[0028] The ball joint drive assembly 63 includes at least three ball joint drive arms arranged in a ring at equal intervals on the inner circumference of the lower end of the protective cylinder 61. Each ball joint drive arm includes a first linear slide module 631, a transmission arm 632, a ball socket 633, and a transmission ball head 634. The first linear slide module 631 is vertically arranged on the inner circumference of the lower end of the protective cylinder 61, and its working end is rotatably connected to one end of the transmission arm 632. The other end of the transmission arm 632 is fixedly provided with the ball socket 633. The transmission ball head 634 is fixedly provided on the circumference of the bottom end of the spherical printing platform 62 and is ball jointly connected to the ball socket 633. By connecting the three sets of ball joint drive arms to the spherical printing platform, the linear displacement is converted into the tilt angle motion of the platform, ensuring smooth and unhindered movement. The independent Z-axis displacement of the first linear slide module is combined with the linkage of the transmission arm, the ball socket, and the transmission ball head to realize the six-degree-of-freedom motion (Z-axis translation + X / Y-axis rotation) of the spherical printing platform.

[0029] The spherical printing platform 62 has a hollow internal periphery and a horizontal mounting plate 621. The transmission ball head 634 is located on the bottom surface of the mounting plate 621. The bottom periphery of the spherical printing platform 62 has a clearance hole 622 corresponding to the transmission ball head 634 for the transmission arm 632 to extend into. This reduces the weight of the spherical printing platform while improving the sensitivity of the ball joint drive arm in driving the spherical printing platform.

[0030] The spherical printing platform 62 has a horizontally circumferential placement groove 62A at its maximum outer diameter. A barrier ring 62B is fitted inside the placement groove 62A to block and scrape away powder material. The barrier ring 62B is elastic and, in this example, preferably made of soft plastic. When the spherical printing platform 62 is working, the barrier ring 62B blocks most of the powder material from the upper part of the rotating cavity 611 and scrapes away the residual powder material on the inner wall of the rotating cavity 611 to the lower part of the rotating cavity 611, preventing the spherical printing platform 62 from getting stuck inside the rotating cavity 611. During printing, excess powder material located in the upper part of the rotating cavity 611 (referring to powder material exceeding the height of the rotating cavity 611) is scraped out by the powder spreading mechanism 3 into the powder recovery box 35. After printing, the operator can clean the powder material in the upper or lower part of the rotating cavity 611 to facilitate the next printing operation.

[0031] The laser scanning mechanism 2 includes a laser generator 21 for emitting a high-energy laser beam and a galvanometer 22 for deflecting the high-energy laser beam onto the tilting printing mechanism, which are arranged laterally on the forming box 5. The high-energy laser beam generated by the laser generator is transmitted to the galvanometer through an optical fiber, and then the galvanometer deflects the high-energy laser beam onto the spherical printing platform for scanning and melting. Specifically, the galvanometer 22 is located on the forming box 5 directly above the tilting printing mechanism 6.

[0032] The powder spreading mechanism 3 includes a second linear slide module 31, a blade holder 32, and a scraper 33. The second linear slide module 31 is horizontally disposed on the side of the bottom surface inside the forming cavity 51. The blade holder 32 is provided on the working end of the second linear slide module 31, and the scraper 33 is connected to the blade holder 32. The scraper is driven to reciprocate along the X-axis by the second linear slide module, so that the powder material fed by the feeding mechanism to the printing plane is evenly spread on the spherical printing platform.

[0033] The powder spreading mechanism 3 also includes a recovery funnel 34 and a powder recovery box 35 connected to the forming cavity 51; the recovery funnel 34 is located at the bottom of the forming box 5 outside the inclined printing mechanism 6, and the powder recovery box 35 is located inside the frame 1 and connected to the recovery funnel 34; by the reciprocating motion of the scraper along the X-axis, excess powder material in the spherical printing platform is recovered and stored in the powder recovery box.

[0034] The feeding mechanism 4 includes a feeding cylinder 41, a piston 42, and an electric push rod 43; the feeding cylinder 41 is fixed to one side of the bottom of the forming box 5, the piston 42 is provided inside the feeding cylinder 41, and the electric push rod 43 is located at the bottom of the feeding cylinder 41 and its working end is connected to the piston 42; the electric push rod 43 can drive the piston 42 to quantitatively transport metal powder material from the feeding cylinder 41 to the printing plane; The molding chamber 5 also includes an air inlet plate 52, an air outlet plate 53, an air inlet plate 54 for sending inert gas into the molding chamber to form a low-oxygen environment, and an air outlet plate 55 for extracting dirty gas containing smoke, oxidized particles and oxygen; the air inlet plate 52 and the air inlet plate 54 are arranged opposite each other in the molding chamber 51 on both sides of the inclined printing mechanism 6, and the air outlet plate 53 and the air outlet plate 55 are arranged opposite each other in the molding chamber 51 on both sides of the feeding mechanism 4. It also includes a control system for controlling the working status of the laser scanning mechanism 2, powder spreading mechanism 3, feeding mechanism 4, forming box 5, and tilting printing mechanism 6; a high-precision encoder is used to provide real-time feedback on the platform position, and the pulse signal of the first or second linear slide module is adjusted through a PID algorithm to ensure displacement and angle accuracy. This allows the laser scanning mechanism, powder spreading mechanism, feeding mechanism, forming box, and tilting printing mechanism to work closely together through timing control. After a single layer of printing is completed, the feeding cylinder quickly replenishes powder, the scraper spreads powder synchronously, and the platform automatically adjusts to the angle of the next layer, adapting to the rapid manufacturing needs of highly complex parts, enabling efficient collaborative operation, and shortening the production cycle of parts.

[0035] Working principle: The control system controls the ball joint drive assembly to raise and lower the spherical printing platform along the Z-axis until it is parallel to the printing plane. Inert gas is injected into the forming cavity through the air inlet plate. The electric push rod drives the piston to quantitatively transport metal powder material from the feeding cylinder to the printing plane. The second linear slide module drives the scraper to move along the X-axis, uniformly scraping the metal powder material fed to the printing plane by the feeding mechanism onto the spherical printing platform. The laser scanning mechanism then laser-melts the powder to form the current layered structure. The ball joint drive assembly then drives the spherical printing platform to perform vertical displacement along the Z-axis and rotation along the X and Y axes to precisely adjust the tilt angle and height of the spherical printing platform. This allows the printing of the next layer to be completed without additional support, avoiding the need for support for the suspended structure. Subsequently, the electric actuator can quantitatively transport the metal powder material from the feeding cylinder to the printing plane by driving the piston. The second linear slide module drives the scraper to evenly scrape the metal powder material onto the spherical printing platform. Excess metal powder material is scraped into the recycling funnel. The scraper then returns to its position and begins a new printing cycle.

[0036] This invention also provides a selective laser melting tilt printing method, which specifically includes the following steps: S1: Seal the molding box and inject inert gas into the molding cavity; S101: Close the molding box door; S102: The air inlet plate and air outlet plate are opened, and inert gas enters from the air inlet plate to vent the air in the molding cavity. S103: When the air outlet plate is closed, the inert gas intake of the air inlet plate is reduced, and the air outlet plate and the air inlet plate are opened to form a circulating air duct. S2: Drive the spherical printing platform to rotate back to zero around the X and Y axes via the ball joint drive assembly, and then raise and lower the spherical printing platform along the Z axis until it is parallel to the printing plane; S3: Evenly spread powder material onto the spherical printing platform; S301: The electric actuator drives the piston to deliver powder material from the feed cylinder to the printing plane; S302: The second linear slide module drives the scraper to move along the X-axis. The scraper spreads the powder material onto the spherical printing platform. After completion, the scraper returns to the side of the feeding cylinder. S4: Activate the laser scanning system to laser melt the powder material on the spherical printing platform to form the current layer structure; S5: Based on the geometric parameters of the next layer of the printed part, the control system drives the ball joint drive assembly to rotate the spherical printing platform around the X and Y axes by a specific angle, and then raises and lowers it along the Z axis. This process repeats S3-S4 to complete the supportless printing process layer by layer. This process tilts the printing platform 61 to a position aligned with the normal vector of the next layer surface to avoid the need to add support to the suspended structure.

[0037] S6: Printing complete.

[0038] The embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A selective laser melting device for tiltable printing, characterized in that: It includes a frame (1), a laser scanning mechanism (2), a powder spreading mechanism (3), a feeding mechanism (4), a forming box (5), and a tilting printing mechanism (6); the frame (1) is provided with a forming box (5) having a forming cavity (51) inside, the laser scanning mechanism (2) is provided on the forming box (5), the powder spreading mechanism (3) is provided on the bottom surface inside the forming cavity (51), and the bottom sides of the forming box (5) are respectively provided with a feeding mechanism (4) and a tilting printing mechanism (6) connected to the forming cavity (51); The tilting printing mechanism (6) includes a protective cylinder (61) that is narrow at the top and wide at the bottom, a spherical printing platform (62), and a ball joint drive assembly (63). The protective cylinder (61) is fixed to one side of the bottom of the forming box (5). The protective cylinder (61) has a rotating cavity (611) that is connected to the forming cavity (51). The spherical printing platform (62) is movably disposed in the upper end of the rotating cavity (611). The ball joint drive assembly (63) is disposed at the lower end of the rotating cavity (611), and its working end is connected to the ball joint drive assembly on the periphery of the bottom end of the spherical printing platform (62). The ball joint drive assembly (63) includes at least three ball joint drive arms arranged in a ring at equal intervals on the inner circumferential side of the lower end of the protective cylinder (61); The ball joint drive arm includes a first linear slide module (631), a transmission arm (632), a ball socket (633), and a transmission ball head (634); the first linear slide module (631) is vertically disposed on the inner circumferential side of the lower end of the protective cylinder (61), and its working end is rotatably connected to one end of the transmission arm (632); the other end of the transmission arm (632) is fixedly provided with a ball socket (633); the transmission ball head (634) is fixedly disposed on the circumferential side of the bottom end of the spherical printing platform (62) and is connected to the ball socket (633) via a ball joint drive. The spherical printing platform (62) has a hollow structure on its inner periphery and is provided with a mounting plate (621) on the side. The transmission ball head (634) is located on the bottom surface of the mounting plate (621). The spherical printing platform (62) has a clearance hole (622) on the bottom periphery corresponding to the transmission ball head (634) for the transmission arm (632) to extend into.

2. The selective laser melting device for tiltable printing according to claim 1, characterized in that: The laser scanning mechanism (2) includes a laser generator (21) and a galvanometer (22) arranged horizontally on the forming box (5); the galvanometer (22) is located on the forming box (5) directly above the tilting printing mechanism (6).

3. A selective laser melting device for tiltable printing according to claim 1 or 2, characterized in that: The powder spreading mechanism (3) includes a second linear slide module (31), a knife holder (32), and a scraper (33); the second linear slide module (31) is arranged laterally on the side of the bottom surface inside the forming cavity (51), and the working end of the second linear slide module (31) is provided with a knife holder (32), and a scraper (33) is connected to the knife holder (32).

4. The selective laser melting device for tiltable printing according to claim 3, characterized in that: The powder spreading mechanism (3) also includes a recycling funnel (34) and a powder recycling box (35) connected to the forming cavity (51); the recycling funnel (34) is located at the bottom of the forming box (5) outside the inclined printing mechanism (6), and the powder recycling box (35) is located inside the frame (1) and connected to the recycling funnel (34).

5. The selective laser melting device for tiltable printing according to claim 1, characterized in that: The feeding mechanism (4) includes a feeding cylinder (41), a piston (42) and an electric push rod (43); the feeding cylinder (41) is fixed on one side of the bottom of the molding box (5), the feeding cylinder (41) is provided with a piston (42), and the electric push rod (43) is located at the bottom of the feeding cylinder (41) and its working end is connected to the piston (42).

6. The selective laser melting device for tiltable printing according to claim 1, characterized in that: The molding box (5) also includes an air inlet plate (52), an air outlet plate (53), an air inlet plate (54), and an air outlet plate (55); the air inlet plate (52) and the air inlet plate (54) are arranged opposite each other in the molding cavity (51) on both sides of the inclined printing mechanism (6), and the air outlet plate (53) and the air outlet plate (55) are arranged opposite each other in the molding cavity (51) on both sides of the feeding mechanism (4).

7. A tilting printing method for a tiltable selective laser melting apparatus according to any one of claims 1-6, characterized in that: S1: Seal the molding box and inject inert gas into the molding cavity; S2: Drive the spherical printing platform to rotate back to zero around the X and Y axes via the ball joint drive assembly, and then raise and lower the spherical printing platform along the Z axis until it is parallel to the printing plane; S3: Evenly spread powder material onto the spherical printing platform; S4: Activate the laser scanning system to laser melt the powder material on the spherical printing platform to form the current layer structure; S5: Based on the geometric parameters of the next layer of the printed part, the control system drives the ball joint drive component to rotate the spherical printing platform around the X and Y axes by a specific angle, and then raises and lowers along the Z axis, repeating S3-S4 to complete the unsupported printing process layer by layer. S6: Printing complete.

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