Isolated galvanometer leveling and focusing device and metal 3D printer

Abstract

The application discloses an isolated galvanometer leveling and focusing device and a metal 3D printer, wherein the device comprises: a mounting base fixed on the top of a forming cavity; a bearing plate slidably assembled on the mounting base in the vertical direction, wherein a clamping locking assembly for locking the bearing plate is arranged at the sliding connection position of the bearing plate and the mounting base; a movable focusing mechanism, comprising: two groups of focusing lead screws symmetrically arranged on both sides of the bearing plate, and a linkage assembly for linkage of the two groups of focusing lead screws to rotate synchronously; and a flexible leveling mechanism, comprising: an outer fixed ring, an inner leveling ring, a plurality of flexible bridges, and a leveling assembly arranged around the inner leveling ring and always abutting against the inner leveling ring under the tensioning action of the flexible bridges to adjust the attitude angle of the inner leveling ring. The application can reduce the additional inclination of the bearing plate in the lifting and focusing process, realize mechanical decoupling of leveling and focusing, and effectively improve the precision and stability of leveling and focusing.

Description

Technical Field

[0001] This invention relates to the field of 3D printing technology, and in particular to an isolated galvanometer leveling and focusing device and a metal 3D printer. Background Technology

[0002] Selective laser melting (SLM) technology is widely used in the manufacturing of high-precision medical products such as orthopedic implants and dental prostheses. In this technology, the relative positional relationship between the galvanometer system and the field lens has a decisive impact on the full-area spot size, scanning geometric accuracy, and energy input consistency. Therefore, the equipment must have high-precision leveling and focusing capabilities, as well as good long-term stability and calibration traceability.

[0003] In existing technologies, some solutions disclose a structure that uses a lifting mechanism to move the galvanometer housing and field lens as a whole to change the focal length, or uses an angle adjustment stage to adjust the parallelism between the galvanometer and the worktable. However, these existing technologies still have the following shortcomings: 1. Leveling mechanisms often use rigid angle tables, shims, or ordinary set screws, which can cause friction, return clearance, and secondary displacement during the adjustment process. 2. Single-sided lead screw or eccentric lifting can easily cause the bearing plate to pitch slightly, resulting in the need to readjust the level after the focus is adjusted; 3. If the adjusting threads, guide rails, and lubrication parts are connected to the metal powder forming cavity, problems such as powder entering the moving parts, particle precipitation, and difficulty in cleaning may easily occur. 4. The elastic reaction force of the sealed bellows may cause disturbance to the adjustment plate and Z-axis position.

[0004] These deficiencies will significantly affect the accuracy of galvanometer leveling and focusing, and consequently the dimensional accuracy of 3D printed products. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the present invention aims to provide an isolated galvanometer leveling and focusing device and a metal 3D printer, which has the advantages of high leveling accuracy, good sealing and isolation and strong stability.

[0006] The objective of this invention is achieved through the following technical solution: According to a first aspect of the present disclosure, an isolated galvanometer leveling and focusing device is provided, comprising: A mounting base fixed to the top of the molding cavity of a 3D printing device; A support plate for mounting a galvanometer assembly is slidably mounted on the mounting base in the vertical direction. A clamping assembly for locking the support plate is provided at the sliding connection between the support plate and the mounting base. A movable focusing mechanism for driving the support plate to move up and down for focusing operations includes: two sets of focusing screws symmetrically arranged on both sides of the support plate, and a linkage assembly for synchronously rotating the two sets of focusing screws. The focusing screws are rotatably mounted on the mounting base and threadedly connected to the support plate. A flexible leveling mechanism supported on the support plate for leveling the galvanometer assembly includes: an outer fixing ring fixed to the support plate; an inner leveling ring movably embedded in the outer fixing ring for loading the galvanometer assembly; a plurality of flexible bridges elastically connecting the outer fixing ring and the inner leveling ring; and a leveling component surrounding the inner leveling ring and constantly pressed against the inner leveling ring by the tension of the flexible bridges to adjust the attitude angle of the inner leveling ring. The flexible bridges have high rigidity in the horizontal direction and elastic deformation capability in the vertical direction.

[0007] To achieve the above technical solution, during the galvanometer leveling and focusing operation, the forming working surface is first determined to be level based on a standard reference plate. The attitude angle of the inner leveling ring is adjusted using the leveling assembly to bring the galvanometer assembly to a predetermined level. Then, the focal plane is determined using a focal point test plate, a coaxial distance measuring device, or a standard molten pool test. Rotating one side of the focusing screw causes the other side's focusing screw to rotate synchronously under the action of the linkage assembly. This allows the support plate to smoothly rise and fall vertically under the action of the focusing screw, adjusting the galvanometer assembly to reach a predetermined working distance from the forming working surface. Finally, the position of the support plate is locked using a clamping assembly. To prevent displacement, the focusing and leveling process can be completed. By adjusting the height of the support plate through two sets of focusing screws, the lifting and lowering load and the additional tilt of the support plate during focusing can be reduced, effectively improving the focusing accuracy. The flexible bridge provides frictionless lateral constraint and elastic warning for the inner leveling ring. Compared with the traditional solution, it can effectively reduce the backlash and particle precipitation caused by sliding pairs, springs and ordinary set screws. The galvanometer assembly moves up and down with the support plate as a whole. During focusing, the horizontal posture of the flexible leveling mechanism is not changed, realizing the mechanical decoupling of leveling and focusing, and effectively improving the accuracy and stability of leveling and focusing.

[0008] In some exemplary embodiments, the leveling assembly has at least three pressure fulcrums evenly distributed around the inner leveling ring, including a fixed spherical surface and two sets of differential adjusters for adjusting the attitude angle of the inner leveling ring.

[0009] To achieve the above technical solution, a single-point positioning of the inner leveling ring is realized by fixing the spherical surface, and two sets of differential regulators work together to adjust the pitch and roll angles of the inner leveling ring, thereby realizing the adjustment of the attitude angle of the inner leveling ring.

[0010] In some exemplary embodiments, the differential regulator includes: A differential screw, wherein the differential screw has a first threaded section and a second threaded section with the same direction of rotation but different pitches, the first threaded section being threadedly connected to the outer fixed ring, and the second threaded section being threadedly connected to an output seat that is guided and slidably connected to the outer fixed ring; A spherical output end fixed to the output socket and abutting against the outer edge of the inner leveling ring; and, Locking assembly for locking or unlocking the differential screw.

[0011] To achieve the above technical solution, when adjusting the attitude angle of the inner leveling ring, the differential screw is rotated. A threaded transmission is formed between the first threaded section and the outer fixed ring, and a threaded transmission is formed between the second threaded section and the output seat. Due to the different pitches of the two threaded sections, the output seat generates a slight axial displacement to push the inner leveling ring through the spherical output end. With the cooperation of the fixed spherical surface, the pitch and roll adjustment of the inner leveling ring is realized. Combined with the elastic constraint of the flexible bridge, precise leveling without backlash is achieved. After leveling is completed, the differential screw can be locked by the locking assembly to prevent attitude drift during subsequent focusing.

[0012] In some exemplary embodiments, the locking component includes: A split locking sleeve is disposed within the outer fixing ring and surrounds the differential screw, wherein one side of the split locking sleeve has an opening; and, A locking element threaded to the split locking sleeve for tightening the opening to lock the differential screw or opening the opening to unlock the differential screw.

[0013] To achieve the above technical solution, by tightening or loosening the locking component, the separate locking sleeve can be controlled to clamp or release the differential screw, thereby locking and unlocking the differential screw. Furthermore, the separate locking sleeve clamps the differential screw radially, which can effectively reduce the disturbance of the fulcrum height caused by the locking action, thus ensuring the stability of the leveling accuracy.

[0014] In some exemplary embodiments, the linkage component is selected individually or in combination from the following structures: a timing pulley assembly, a timing sprocket assembly, or a timing gear assembly.

[0015] In some exemplary embodiments, the mounting base is provided with a sliding guide structure, and the clamping assembly includes: a sliding block connected to the two side bearing plates and slidably connected to the sliding guide structure, and a clamping locking member threadedly connected to the sliding block to clamp or release the sliding guide structure.

[0016] To achieve the above technical solution, the position of the bearing plate can be locked by tightening the clamping and locking parts against the sliding guide structure, thus preventing secondary displacement after focusing.

[0017] In some exemplary embodiments, the mounting base is provided with a limit block at the extreme position of the vertical movement of the support plate, and an adjustment scale is provided between the limit blocks.

[0018] By implementing the above technical solution, the limit stop can prevent mechanical collisions caused by the overtravel of the support plate, and the adjustment scale makes it easy to read the displacement, which is beneficial for subsequent repeated positioning and calibration record traceability.

[0019] In some exemplary embodiments, an adapter plate for mounting a galvanometer assembly is fixed on the inner leveling ring. The adapter plate, the inner leveling ring, and the carrier plate are provided with a through-hole for light transmission. The optical axis of the galvanometer assembly passes through the through-hole and faces the molding cavity.

[0020] The above technical solution is achieved by setting up an adapter plate to facilitate the installation and removal of the galvanometer assembly, forming an integrated optical module with the galvanometer assembly, which facilitates overall leveling and lifting / focusing.

[0021] In some exemplary embodiments, a corrugated sealing tube is provided between the light-emitting side of the galvanometer assembly and the top of the forming cavity, and the axial deformation stroke of the corrugated sealing tube is greater than the focusing stroke of the support plate.

[0022] By implementing the above technical solution, the corrugated sealing pipe can effectively isolate dust and metal vapor in the molding cavity.

[0023] According to a second aspect of the present disclosure, a metal 3D printer is provided, comprising: A forming cavity for forming laser-printed controls and performing laser melting molding; and, The isolated galvanometer leveling and focusing device as described in the first aspect is installed on the top of the forming cavity.

[0024] In summary, compared with the prior art, the present invention has the following beneficial effects: This invention provides an isolated galvanometer leveling and focusing device and a metal 3D printer. During galvanometer leveling and focusing, the level of the forming working surface is first determined based on a standard reference plate. The attitude angle of the inner leveling ring is adjusted by the leveling component to bring the galvanometer assembly to a predetermined level. Then, the focal plane is determined using a focal point test plate, a coaxial distance measuring device, or a standard molten pool test. Rotating one side of the focusing screw causes the other side's focusing screw to rotate synchronously under the action of the linkage component. This allows the support plate to smoothly rise and fall vertically under the action of the focusing screw, adjusting the galvanometer assembly to reach a predetermined working distance from the forming working surface. The clamping assembly locks the position of the support plate to prevent displacement, thus completing the focusing and leveling process. The height of the support plate is adjusted by two sets of focusing screws, which can reduce the lifting and lowering load and the additional tilt of the support plate during focusing, effectively improving the focusing accuracy. The flexible bridge provides frictionless lateral constraint and elastic warning for the inner leveling ring. Compared with the traditional solution, it can effectively reduce the backlash and particle precipitation caused by sliding pairs, springs and ordinary set screws. The galvanometer assembly moves up and down with the support plate as a whole. During focusing, it does not change the horizontal posture already completed by the flexible leveling mechanism, realizing the mechanical decoupling of leveling and focusing, and effectively improving the accuracy and stability of leveling and focusing. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the isolated galvanometer leveling and focusing device in an embodiment of the present invention.

[0026] Figure 2 This is a schematic diagram of the flexible leveling mechanism in an embodiment of the present invention.

[0027] Figure 3 This is a schematic diagram of the differential regulator in an embodiment of the present invention.

[0028] Figure 4 This is a schematic diagram of the adapter plate in an embodiment of the present invention.

[0029] The numbers and letters in the diagram represent the names of the corresponding components: 10. Mounting base; 11. Molding cavity top plate; 12. Sliding guide structure; 13. Limiting block; 14. Adjusting scale; 20. Bearing plate; 30. Galvanometer assembly; 31. Galvanometer box; 32. Field lens; 33. Optical sleeve; 34. Corrugated sealing tube; 341. Upper sealing flange; 342. Lower sealing flange; 40. Clamping assembly; 41. Sliding block; 42. Clamping element; 50. Movable focusing mechanism; 51. Focusing screw; 52. Linkage assembly; 53. Focusing handwheel; 6 0. Flexible leveling mechanism; 61. Outer fixed ring; 611. Wear-resistant contact seat; 62. Inner leveling ring; 63. Flexible bridge; 64. Leveling assembly; 641. Fixed spherical surface; 642. Differential adjuster; 6421. Differential screw; 6422. Output seat; 6423. Spherical output end; 6424. Locking assembly; 64241. Split locking sleeve; 64242. Locking component; 65. Adapter plate; 651. Light passage; 652. Cylindrical positioning pin; 653. Rhomboid positioning pin. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] like Figures 1 to 4 As shown, a first aspect of the present invention provides an isolated galvanometer leveling and focusing device, comprising: a mounting base 10 fixed to the top of the molding cavity of a 3D printing equipment; a support plate 20 slidably mounted on the mounting base 10 in a vertical direction for loading a galvanometer assembly 30, wherein a clamping assembly 40 for locking the support plate 20 is provided at the sliding connection between the support plate 20 and the mounting base 10; a movable focusing mechanism 50 for driving the support plate 20 to move up and down to perform focusing operations; and a flexible leveling mechanism 60 supported on the support plate 20 for leveling the galvanometer assembly 30.

[0032] Specifically, the mounting base 10 can be fixed to the top plate 11 of the forming cavity by welding, bolting or other means. It can be understood that the mounting base 10 is a rigid frame structure suitable for the installation of the bearing plate 20, the movable focusing mechanism 50 and other structures. Both the mounting base 10 and the bearing plate 20 can be integrally processed from materials such as aluminum alloy or stainless steel to ensure the overall structural strength.

[0033] The mounting base 10 is provided with a sliding guide structure 12, which can be in the form of a slide rail, guide rod, etc. Taking the sliding guide structure 12 as an example, linear slide rails are symmetrically arranged on both sides of the support plate 20 on the mounting base 10. The clamping assembly 40 includes: a sliding block 41 connected to the two support plates 20 and slidably connected to the sliding guide structure 12, and a clamping locking member 42 threadedly connected to the sliding block 41 to clamp or release the sliding guide structure 12. The sliding block 41 can be fixed to the two sides of the support plate 20 by means of integral molding, welding, bolt connection, etc. The clamping locking member 42 can be, for example, a screw. The sliding block 41 can also be in the form of a split clamping block or a wedge-shaped pressure block. When the clamping locking member 42 is locked, it can press against the slide rail or drive the sliding block 41 to clamp the slide rail, thereby fixing the sliding block 41 relative to the slide rail. By tightening the clamping locking member 42 to press against the sliding guide structure 12, the position of the support plate 20 can be locked to prevent secondary displacement after focusing.

[0034] The movable focusing mechanism 50 includes: two sets of focusing screws 51 symmetrically arranged on both sides of the support plate 20, and a linkage component 52 for synchronously rotating the two sets of focusing screws 51. The focusing screws 51 are rotatably mounted on the mounting base 10 and threadedly connected to the support plate 20. Typically, bearing seats are provided at both ends of the adjusting screw on the mounting base 10. The focusing screws 51 are mounted in the bearing seats through bearings to ensure that the focusing screws 51 can rotate stably and smoothly. A screw nut for threaded connection of the focusing screws 51 is fixed on the support plate 20, thereby forming a stable threaded transmission with the focusing screws 51 and driving the support plate 20 to rise and fall smoothly in the vertical direction.

[0035] The linkage component 52 can be selected individually or in combination from the following structures: synchronous belt pulley assembly, synchronous sprocket assembly, or synchronous gear assembly. Taking the synchronous gear assembly as an example, the linkage component 52 includes a first helical gear fixed to the end of the adjusting screw, a synchronous shaft rotatably mounted on the mounting base 10, and a second helical gear fixed to both ends of the synchronous shaft and meshing with the first helical gear. Through the linkage of the synchronous shaft and the meshing transmission of the first and second helical gears, the two sets of focusing screws 51 are kept rotating synchronously. Usually, in order to facilitate the rotation of the focusing screw, a focusing handwheel 53 can be provided at the end of one of the focusing screws 51. In some embodiments, a motor can also be used to drive the focusing screw 51 to rotate in order to achieve automated focusing control.

[0036] In some embodiments, the linkage component 52 may also employ a synchronous belt pulley assembly and a synchronous sprocket assembly. The synchronous belt pulley assembly includes a synchronous pulley fixed to the end of the focusing screw 51 and a synchronous belt wound around the synchronous pulley. The synchronous sprocket assembly includes a synchronous sprocket fixed to the end of the focusing screw 51 and a synchronous chain wound around the synchronous sprocket. In comparison, the transmission accuracy of the synchronous gear assembly is obviously higher than that of the synchronous belt pulley assembly and the synchronous sprocket assembly. Therefore, the linkage component 52 preferably employs a synchronous gear assembly.

[0037] Meanwhile, a limit stop 13 is provided on the mounting base 10 at the limit position of the vertical movement of the support plate 20, and an adjustment scale 14 is provided between the limit stops 13. The adjustment scale 14 has a travel scale. The limit stops 13 can prevent the support plate from exceeding the adjustment range and causing mechanical collision. The adjustment scale 14 makes it easy to read the displacement, which is beneficial for subsequent repeated positioning and calibration record traceability. In order to reduce mechanical collision, in some embodiments, a buffer pad or elastic damping element can also be provided on the limit stops 13 to further absorb impact energy and protect precision components.

[0038] The flexible leveling mechanism 60 includes: an outer fixing ring 61 fixed to the bearing plate 20; an inner leveling ring 62 movably embedded in the outer fixing ring 61 for loading the galvanometer assembly 30; a plurality of flexible bridges 63 elastically connecting the outer fixing ring 61 and the inner leveling ring 62; and a leveling component 64 surrounding the inner leveling ring 62 and constantly pressed against the inner leveling ring 62 by the tension of the flexible bridges 63 to adjust the attitude angle of the inner leveling ring 62. The flexible bridges 63 have high rigidity in the horizontal direction and elastic deformation capability in the vertical direction.

[0039] Specifically, the outer fixing ring 61 and the inner leveling ring 62 are nested together, with a certain gap between the inner wall of the outer fixing ring 61 and the outer wall of the inner leveling ring 62 to provide space for the deflection and focusing of the inner leveling ring 62. Flexible bridges 63 are evenly distributed along the circumference. In this embodiment, three sets of flexible bridges 63 are evenly distributed between the outer fixing ring 61 and the inner leveling ring 62. The flexible bridges 63 have high stiffness in the horizontal direction and around the optical axis, and elastic deformation capability in the vertical direction. They are used to restrict the lateral translation and rotation of the inner moving ring, while allowing it to produce small-angle pitch and roll. That is, the thickness direction of the flexible bridge 63 is vertical, allowing it to undergo elastic bending deformation in the vertical direction, while restricting the horizontal translation of the inner leveling ring 62, i.e., rotation around the optical axis. In other embodiments, other numbers of flexible bridges 63 can be provided, but it should be ensured that the inner leveling ring 62 can produce small-angle tilts in two directions and restrict lateral movement.

[0040] The leveling assembly 64 has at least three evenly distributed pressure fulcrums surrounding the inner leveling ring 62, including a fixed spherical surface 641 and two sets of differential adjusters 642. The differential adjusters 642 are used to adjust the attitude angle of the inner leveling ring 62. The elastic restoring force of the flexible bridge 63 enables the inner leveling ring 62 to continuously press against the fixed spherical surface 641 and the two differential adjusters 642 throughout the entire leveling range. Therefore, after setting the flexible bridge 63, it is not necessary to set an independent preload spring near the forming cavity. The fixed spherical surface 641 realizes the single-point positioning of the inner leveling ring 62. The two sets of differential adjusters 642 coordinate to adjust the pitch and roll angles of the inner leveling ring 62, realizing the adjustment of the attitude angle of the inner leveling ring 62. In some embodiments, the differential adjuster 642 can be replaced with a differential head with equivalent differential displacement output.

[0041] The differential adjuster 642 includes: a differential screw 6421, which has a first threaded section and a second threaded section with the same direction of rotation but different pitches. The first threaded section is threadedly connected to an outer retaining ring 61, and the second threaded section is threadedly connected to an output seat 6422 that is guided and slidably connected to the outer retaining ring 61; a spherical output end 6423 fixed to the output seat 6422 and abutting against the outer edge of the inner leveling ring 62; and a locking assembly 6424 for locking or unlocking the differential screw 6421.

[0042] Specifically, a threaded hole is provided on the outer fixed ring 61 for the differential screw 6421 to pass through. The differential screw 6421 passes through the threaded hole and is threadedly engaged with it through the first threaded section. The output seat 6422 and the outer fixed ring 61 can achieve sliding constraint through the matching guide groove and guide block, so that the output seat 6422 can only move radially and cannot rotate. The output seat 6422 is provided with a threaded hole that is threadedly engaged with the second threaded section. When the differential screw 6421 rotates, a threaded transmission is formed between it and the output seat 6422, driving the output seat 6422 to move radially. The spherical output end 6423 moves radially with the output seat 6422 to push the inner leveling ring 62, changing its pitch and roll angles. Since the differential screw 6421 forms a threaded transmission with the outer fixed ring 61 at the same time, the theoretical displacement of the spherical output end 6423 when the differential screw 6421 rotates one revolution is the difference between two screw pitches, thus achieving a displacement resolution smaller than that of a conventional single-threaded regulator.

[0043] When adjusting the attitude angle of the inner leveling ring 62, the differential screw 6421 is rotated. A threaded transmission is formed between the first threaded section and the outer fixed ring 61, and a threaded transmission is formed between the second threaded section and the output seat 6422. Due to the different pitches of the two threaded sections, the output seat 6422 generates a slight axial displacement to push the inner leveling ring 62 through the spherical output end 6423. With the cooperation of the fixed spherical surface 641, the pitch and roll adjustment of the inner leveling ring 62 is realized. With the elastic constraint of the flexible bridge 63, precise leveling without backlash is achieved. After leveling is completed, the differential screw 6421 can be locked by the locking component 6424 to prevent attitude drift during subsequent focusing.

[0044] The locking assembly 6424 includes: a split locking sleeve 64241 disposed within the outer retaining ring 61 and surrounding the differential screw 6421, the split locking sleeve 64241 having an opening on one side; and a locking member 64242 threadedly connected to the split locking sleeve 64241 for tightening the opening to lock the differential screw 6421 or opening the opening to unlock the differential screw 6421. The split locking sleeve 64241 can be fixed to the outer fixing ring 61 by welding, snap-fitting, etc. The locking element 64242 can also be a screw. The locking element 64242 passes radially through the ear of the split locking sleeve 64241 and presses against both sides of the opening. By tightening or loosening the locking element 64242, the split locking sleeve 64241 can be controlled to clamp or release the differential screw 6421, realizing the locking and unlocking of the differential screw 6421. The split locking sleeve 64241 clamps the differential screw 6421 radially without generating axial clamping force. Therefore, it can effectively reduce the disturbance of the fulcrum height caused by the locking action, reduce the angle drift after leveling and locking, and thus ensure the stability of the leveling accuracy.

[0045] In this embodiment, an adapter plate 65 for mounting the galvanometer assembly 30 is fixed on the inner leveling ring 62. The adapter plate 65, the inner leveling ring 62 and the carrier plate 20 are provided with a through light-passing port 651. The optical axis of the galvanometer assembly 30 passes through the light-passing port 651 and faces the forming cavity. The adapter plate 65 can facilitate the mounting and dismounting of the galvanometer assembly 30 and form an integral optical module with the galvanometer assembly 30, which is convenient for overall leveling and lifting and focusing.

[0046] The adapter plate 65 is mounted on the inner leveling ring 62 via cylindrical locating pins 652, rhomboid locating pins 653, and fastening screws. The cylindrical locating pins 652 limit the two translational directions, while the rhomboid locating pins 653 limit rotation around the Z-axis and release the hole spacing error between the two locating pins, preventing over-positioning. A detection reference surface can also be set on the adapter plate 65. This detection reference surface is machined under the same clamping reference as the galvanometer mounting surface, and is used to place an electronic level or as a reference for laser interferometry.

[0047] The galvanometer assembly 30 includes a galvanometer box 31 and a field lens 32 connected in sequence. The galvanometer box 31 contains a galvanometer mirror for deflecting the laser. The field lens 32 is provided with an optical sleeve 33 for protection. A detachable protective window assembly can also be provided at the lower end of the optical sleeve 33 to isolate splashes and metal powder. The light-emitting end of the field lens 32 is the light-emitting side of the galvanometer assembly 30.

[0048] A corrugated sealing tube 34 is provided between the light-emitting side of the galvanometer assembly 30 and the top of the forming cavity. The axial deformation stroke of the corrugated sealing tube 34 is greater than the focusing stroke of the support plate 20. The corrugated sealing tube 34 can be made of welded stainless steel, which can adapt to the maximum deflection angle of the flexible leveling mechanism 60. The corrugated sealing tube 34 is sealed to the optical sleeve 33 through the upper sealing flange 341 and sealed to the top plate 11 of the forming cavity through the lower sealing flange 342. A sealing ring resistant to inert atmosphere and cleaning agent can be provided on the sealing surface. The corrugated sealing tube 34 can effectively isolate dust and metal vapor in the forming cavity.

[0049] When performing galvanometer leveling and focusing operations, first determine the level of the forming working surface based on the standard reference plate. Adjust the attitude angle of the inner leveling ring 62 by adjusting the two sets of differential adjusters 642 so that the galvanometer assembly 30 reaches the predetermined level. After adjustment, the horizontal error of the reference surface in two mutually perpendicular directions can be measured to determine whether the predetermined level has been reached. When the predetermined level has been reached, the differential screw 6421 is locked by the locking assembly 6424 and the measurement is repeated. Next, the focal plane is determined by the focal test plate, coaxial distance measuring device or standard molten pool test. The focusing screw 51 on one side is rotated by the focusing handwheel 53. Under the action of the linkage assembly 52, the focusing screw on the other side rotates synchronously. Thus, under the action of the focusing screw 51, the support plate 20 is raised and lowered smoothly in the vertical direction. Adjust the galvanometer assembly 30 and the forming working surface to reach the predetermined working distance. The position of the support plate 20 is locked by the clamping assembly 40 to prevent displacement. The focusing and leveling process is completed. Finally, the focusing screw 51 is locked by the clamping assembly 40 and the corresponding stroke scale is recorded. By adjusting the height of the support plate 20 using two sets of focusing screws, the lifting and lowering load and the additional tilt of the support plate 20 during focusing can be reduced, effectively improving focusing accuracy. The flexible bridge 63 provides frictionless lateral constraint and elastic warning for the inner leveling ring 62. Compared with the traditional solution, this can effectively reduce the backlash and particle precipitation caused by sliding pairs, springs and ordinary set screws. The galvanometer assembly 30 moves up and down with the support plate 20 as a whole. During focusing, the horizontal posture of the flexible leveling mechanism 60 is not changed, realizing the mechanical decoupling of leveling and focusing, and effectively improving the accuracy and stability of leveling and focusing.

[0050] A second aspect of the present invention provides a metal 3D printer, comprising: a forming cavity for forming laser printing controls and performing laser melting forming; and an isolated galvanometer leveling and focusing device as described in the first aspect, the isolated galvanometer leveling and focusing device being installed on the top of the forming cavity.

[0051] Understandably, the top plate 11 of the molding cavity is also provided with an opening corresponding to the light-transmitting port 651 to allow the laser to pass through. The laser generated by the galvanometer assembly 30 enters the molding cavity through this opening and is sealed to the molding cavity through the bellows, so that all moving pairs are arranged outside the molding cavity, thereby effectively preventing powder from entering the moving pairs.

[0052] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention. These are all equivalent modifications and improvements made to the above embodiments based on the essential technology of the present invention, and all of these fall within the protection scope of the present invention.

Claims

1. An isolated galvanometer leveling and focusing device, characterized in that, include: A mounting base fixed to the top of the molding cavity of a 3D printing device; A support plate for mounting a galvanometer assembly is slidably mounted on the mounting base in the vertical direction. A clamping assembly for locking the support plate is provided at the sliding connection between the support plate and the mounting base. A movable focusing mechanism for driving the support plate to move up and down for focusing operations includes: two sets of focusing screws symmetrically arranged on both sides of the support plate, and a linkage assembly for synchronously rotating the two sets of focusing screws. The focusing screws are rotatably mounted on the mounting base and threadedly connected to the support plate. A flexible leveling mechanism supported on the support plate for leveling the galvanometer assembly includes: an outer fixing ring fixed to the support plate; an inner leveling ring movably embedded in the outer fixing ring for loading the galvanometer assembly; a plurality of flexible bridges elastically connecting the outer fixing ring and the inner leveling ring; and a leveling component surrounding the inner leveling ring and constantly pressed against the inner leveling ring by the tension of the flexible bridges to adjust the attitude angle of the inner leveling ring. The flexible bridges have high rigidity in the horizontal direction and elastic deformation capability in the vertical direction.

2. The isolated galvanometer leveling and focusing device according to claim 1, characterized in that, The leveling assembly has at least three pressure fulcrums evenly distributed around the inner leveling ring, including a fixed spherical surface and two sets of differential adjusters, the differential adjusters being used to adjust the attitude angle of the inner leveling ring.

3. The isolated galvanometer leveling and focusing device according to claim 2, characterized in that, The differential regulator includes: A differential screw, wherein the differential screw has a first threaded section and a second threaded section with the same direction of rotation but different pitches, the first threaded section being threadedly connected to the outer fixed ring, and the second threaded section being threadedly connected to an output seat that is guided and slidably connected to the outer fixed ring; A spherical output end fixed to the output socket and abutting against the outer edge of the inner leveling ring; and, Locking assembly for locking or unlocking the differential screw.

4. The isolated galvanometer leveling and focusing device according to claim 3, characterized in that, The locking assembly includes: A split locking sleeve is disposed within the outer fixing ring and surrounds the differential screw, wherein one side of the split locking sleeve has an opening; and, A locking element threaded to the split locking sleeve for tightening the opening to lock the differential screw or opening the opening to unlock the differential screw.

5. The isolated galvanometer leveling and focusing device according to claim 1, characterized in that, The linkage component is selected individually or in combination from the following structures: synchronous belt pulley assembly, synchronous sprocket assembly, or synchronous gear assembly.

6. The isolated galvanometer leveling and focusing device according to claim 1, characterized in that, The mounting base is provided with a sliding guide structure, and the clamping assembly includes: a sliding block connected to the two side bearing plates and slidably connected to the sliding guide structure, and a clamping locking member threadedly connected to the sliding block to clamp or release the sliding guide structure.

7. The isolated galvanometer leveling and focusing device according to claim 1, characterized in that, The mounting base is provided with a limit block at the limit position of the vertical movement of the bearing plate, and an adjustment scale is provided between the limit blocks.

8. The isolated galvanometer leveling and focusing device according to claim 1, characterized in that, An adapter plate for mounting the galvanometer assembly is fixed on the inner leveling ring. The adapter plate, the inner leveling ring, and the carrier plate are provided with a through-hole for light transmission. The optical axis of the galvanometer assembly passes through the through-hole and faces the molding cavity.

9. The isolated galvanometer leveling and focusing device according to claim 1, characterized in that, A corrugated sealing tube is provided between the light-emitting side of the galvanometer assembly and the top of the forming cavity, and the axial deformation stroke of the corrugated sealing tube is greater than the focusing stroke of the support plate.

10. A metal 3D printer, characterized in that, include: A forming cavity for forming laser-printed controls and performing laser melting molding; and, The isolated galvanometer leveling and focusing device as described in any one of claims 1-9, wherein the isolated galvanometer leveling and focusing device is installed on the top of the forming cavity.

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