A high-precision laser welding device with variable focal depth

Abstract

A high-precision laser welding device with variable focal depth, where a high-precision linear guide is fixedly connected to the upper end of the welding plate; two limit frames are respectively sleeved outside both ends of the high-precision linear guide, and their bottom ends are fixedly connected to the upper end surface of the welding plate; 4 high-precision sliders are assembled on the high-precision linear guide and slide from left to right in sequence; a four-dimensional optical adjustment frame, a five-dimensional optical adjustment frame A, a five-dimensional optical adjustment frame B, and a five-dimensional optical adjustment frame C are respectively fixedly installed on the 4 high-precision sliders; a laser access head is installed in the mounting hole at the center of the four-dimensional optical adjustment frame, and a plano-convex lens is installed in the five-dimensional adjustment frame. Through the combined design of optical components, the adjustment of the laser spot diameter in the range of micrometers to sub-millimeters is realized, and at the same time, the adjustment of the focal depth size is achieved. Through the optimized combination of the spot and the focal depth, the deformation-free and high-precision welding of different types and different thicknesses of transparent polymer plates is realized, meeting the requirements of different welding processes of products.

Description

Technical Field

[0001] The present invention belongs to the technical field of laser welding, and particularly relates to a high-precision laser welding device with variable focal depth. Background Art

[0002] Laser welding is a process of locally heating a small area of the processed material with a laser beam having a high energy density, and the material absorbs the laser energy and melts to achieve the purpose of welding. For the welding of transparent polymers, it is required that the upper layer material has a high transmittance to the laser and the lower layer material has a high absorption of the laser, so as to complete the welding between the upper and lower layer materials. In the actual processing and production process, due to different welding materials and welding processes, different combinations of spot size and focal depth are often required to be achieved. The existing laser welding heads all adopt a two-lens fixed design, with the output spot size and focal depth being fixed and unable to be adjusted, and the spot size is in the millimeter order of magnitude, and the focal depth dimension is in the centimeter order of magnitude. As a result, when the laser power is low, welding cannot be achieved, and after the laser power is increased, the upper polymer material absorbs heat and deforms, and the energy cannot reach the contact surface between the upper and lower layer materials. Especially for relatively thick (>3 mm) transparent polymer materials, the existing welding devices cannot achieve welding. Therefore, there is an urgent need to provide a transparent polymer welding device with variable focus and variable focal depth, which can flexibly adjust the spot size and focal depth to meet the welding requirements of different materials and processes. Summary of the Invention

[0003] Aiming at the problems existing in the above-mentioned prior art, the present invention provides a high-precision laser welding device with variable focal depth, which can adjust the spot diameter only by adjusting the distance between the lenses without replacing any lenses, and at the same time can adjust the focal depth corresponding to different spots, meet the welding requirements of different materials and processes, and ensure a small weld width.

[0004] To achieve the above object, the present invention provides a high-precision laser welding device with variable focal depth, including a laser access head, a welding plate, a high-precision linear guide rail, a limit frame, a high-precision slider A, a high-precision slider B, a high-precision slider C, a high-precision slider D, a four-dimensional optical adjustment frame, a five-dimensional optical adjustment frame A, a five-dimensional optical adjustment frame B, and a five-dimensional optical adjustment frame C;

[0005] The length direction of the welding plate extends along the left-right direction;

[0006] The length direction of the high-precision linear guide rail is consistent with the length direction of the welding plate, and it is fixedly connected to the upper end of the welding plate;

[0007] Two limit frames are respectively sleeved outside both ends of the high-precision linear guide rail, and their bottom ends are fixedly connected to the upper end surface of the welding plate;

[0008] The high-precision slider A, high-precision slider B, high-precision slider C and high-precision slider D are assembled on the high-precision linear guide and slide from left to right in sequence;

[0009] The four-dimensional optical adjustment frame, five-dimensional optical adjustment frame A, five-dimensional optical adjustment frame B and five-dimensional optical adjustment frame C are respectively fixedly installed on the high-precision slider A, high-precision slider B, high-precision slider C and high-precision slider D; The five-dimensional optical adjustment frame A, five-dimensional optical adjustment frame B and five-dimensional optical adjustment frame C are respectively installed with plano-convex lens A, plano-convex lens B and plano-convex lens C; The plano-convex lens A, plano-convex lens B and plano-convex lens C have high transmittance for 1.9 - 2.1μm band laser, and the lens parameters are F1 = 100mm, F2 = 50mm, F3 = 50mm in sequence, the distance d1 between the laser beam and the plano-convex lens A is 50mm, the distance d2 from the plano-convex lens A to the plano-convex lens B is 100mm, and the distance from the plano-convex lens B to the plano-convex lens C is 120mm - 150mm.

[0010] The laser access head is installed in the mounting hole at the center of the four-dimensional optical adjustment frame, and the laser beam source accessed by the laser access head is configured to emit a laser beam with a wavelength of 2 microns.

[0011] As a preference, the five-dimensional optical adjustment frame A, five-dimensional optical adjustment frame B and five-dimensional optical adjustment frame C are all AMM5-1A adjustment frames.

[0012] As a preference, the limiting frame is in an inverted U shape.

[0013] Furthermore, in order to facilitate the positioning of the welding plate, a positioning plate is further included. The front side and the rear side of the middle part of the welding plate each have an extension part extending outward, and a pair of positioning holes B are respectively opened at both ends of the length direction of the extension part; The length direction of the positioning plate extends along the front-rear direction, and a plurality of pairs of positioning holes A are opened along the front-rear direction, and each pair of positioning holes A is arranged to be adapted to a pair of positioning holes B; The positioning plate is arranged in a fitting manner below the middle part of the welding plate and is fixedly connected by positioning bolts passing through each pair of positioning holes A and a pair of positioning holes B.

[0014] In the present invention, by assembling high-precision sliders A, B, C, and D on a high-precision linear guide, and installing a four-dimensional optical adjustment mount, a five-dimensional optical adjustment mount A, a five-dimensional optical adjustment mount B, and a five-dimensional optical adjustment mount C on the high-precision sliders A, B, C, and D respectively, precise adjustment of the distance between each adjustment mount can be achieved, thereby meeting the requirements of precise adjustment. Installing the laser access head in the mounting hole at the center of the four-dimensional optical adjustment mount can achieve displacement adjustment of the laser access head in the tilt Y angle, tilt Z angle, translation X direction, and translation Y direction, and thus the output angle of the laser emitted by the laser access head can be flexibly adjusted according to different working conditions; after respectively installing plano-convex lenses in the five-dimensional optical adjustment mount A, the five-dimensional optical adjustment mount B, and the five-dimensional optical adjustment mount C, displacement adjustment of the installed lens in the tilt Y angle, tilt Z angle, translation X direction, translation Y direction, and translation Z direction can be achieved according to different requirements. Through the combined design of optical components, adjustment of the laser spot diameter in the range of micrometers to sub-millimeters can be achieved, and at the same time, adjustment of the depth of focus can be realized. Through the optimized combination of the spot and the depth of focus, the effects of high transmittance of the laser on the upper-layer welding material and high absorption by the contact surface of the upper and lower-layer materials are achieved, realizing deformation-free and high-precision welding of different types and different thicknesses of transparent polymer plates, solving the problem of laser welding of thick transparent polymer plates, and by adjusting the distance between the plano-convex lenses of the welding device, it is possible to meet the requirements of different welding processes for products using a set of welding devices. Description of the Drawings

[0015] Figure 1 is a schematic structural diagram of the present invention;

[0016] Figure 2 is Figure 1 the front view of

[0017] Figure 3 is Figure 1 the top view of

[0018] Figure 4 is an optical path simulation diagram;

[0019] Figure 5 is a curve graph simulated by the optical software rezonator with a spot radius R of 100 micrometers and a depth of focus DOF of 5 mm;

[0020] Figure 6 is Figure 5 the schematic diagram of the actual weld width of the optical parameters shown;

[0021] Figure 7 is a curve graph simulated by the optical software rezonator with a spot radius R of 60 micrometers and a depth of focus DOF of 2 mm;

[0022] Figure 8 is Figure 7 Schematic diagram of the actual weld width with the optical parameters shown;

[0023] Figure 9 is a schematic diagram of the incident laser spot acting on the upper and lower layer polymers.

[0024] In the figure: 1. Laser access head, 2. Welding plate, 3. Four-dimensional optical adjustment frame, 4. Five-dimensional optical adjustment frame A, 5. Five-dimensional optical adjustment frame B, 6. Five-dimensional optical adjustment frame C, 7. High-precision linear guide rail, 8. High-precision slider A, 9. High-precision slider B, 10. High-precision slider C, 11. Limit frame, 12. High-precision slider D, 13. Positioning hole B, 14. Extension part, 15. Fixed plate, 16. Positioning hole A, 17. Fixing hole, 18. Plano-convex lens A, 19. Plano-convex lens B, 20. Plano-convex lens C, 21. Upper surface of the upper layer polymer material, 22. Incident laser spot, 23. Contact surface between the upper and lower layer polymer materials, 24. Upper layer polymer, 25. Lower layer polymer. Detailed implementation manners

[0025] The present invention will be further described below in conjunction with the accompanying drawings.

[0026] As Figures 1 to 3 shown, a high-precision laser welding device with variable focal depth includes a laser access head 1, a welding plate 2, a high-precision linear guide rail 7, a limit frame 11, a high-precision slider A 8, a high-precision slider B 9, a high-precision slider C 10, a high-precision slider D 12, a four-dimensional optical adjustment frame 3, a five-dimensional optical adjustment frame A 4, a five-dimensional optical adjustment frame B 5 and a five-dimensional optical adjustment frame C 6;

[0027] The length direction of the welding plate 2 extends along the left-right direction;

[0028] The length direction of the high-precision linear guide rail 7 is consistent with the length direction of the welding plate 2, and it is fixedly connected to the upper end of the welding plate 2;

[0029] Two limit frames 11 are respectively sleeved outside both ends of the high-precision linear guide rail 7, and their bottom ends are fixedly connected to the upper end surface of the welding plate 2;

[0030] The high-precision slider A 8, the high-precision slider B 9, the high-precision slider C 10 and the high-precision slider D 12 are assembled on the high-precision linear guide rail 7 and slide from left to right in sequence;

[0031] The four-dimensional optical adjustment mount 3, five-dimensional optical adjustment mount A4, five-dimensional optical adjustment mount B5, and five-dimensional optical adjustment mount C6 are respectively fixedly installed on the high-precision slider A8, high-precision slider B9, high-precision slider C10, and high-precision slider D12; further, the five-dimensional optical adjustment mount A4, five-dimensional optical adjustment mount B5, and five-dimensional optical adjustment mount C6 are respectively equipped with plano-convex lens A18, plano-convex lens B19, and plano-convex lens C20.

[0032] The plano-convex lens A18, plano-convex lens B19, and plano-convex lens C20 have a high transmittance for 1.9 - 2.1μm band lasers. The lens parameters are F1 = 100mm, F2 = 50mm, F3 = 50mm in sequence. The distance d1 between the laser beam and the plano-convex lens A18 is 50mm, the distance d2 from the plano-convex lens A18 to the plano-convex lens B19 is 100mm, and the distance from the plano-convex lens B19 to the plano-convex lens C20 is 120mm - 150mm.

[0033] The laser access head 1 is installed in the mounting hole at the center of the four-dimensional optical adjustment mount 3.

[0034] As a preference, the laser beam source accessed by the laser access head 1 is configured to emit a laser beam with a wavelength of 2 microns, preferably a fiber laser.

[0035] As a preference, the five-dimensional optical adjustment mount A4, five-dimensional optical adjustment mount B5, and five-dimensional optical adjustment mount C6 are all AMM5 - 1A adjustment mounts.

[0036] As a preference, the limit frame 11 is in an inverted U shape.

[0037] To facilitate the positioning of the welding plate, a positioning plate 15 is further included. The front side and the rear side of the middle part of the welding plate 2 each have an extension part 14 extending outward. A pair of positioning holes B13 are respectively opened at both ends of the extension part 14 in the length direction; the length direction of the positioning plate 15 extends along the front - rear direction, and a plurality of pairs of positioning holes A16 are opened along the front - rear direction. Each pair of positioning holes A16 is arranged to be adapted to a pair of positioning holes B13; the positioning plate 15 is arranged to fit under the middle part of the welding plate 2 and is fixedly connected by positioning bolts passing through each pair of positioning holes A16 and a pair of positioning holes B13.

[0038] In the present invention, by assembling high-precision sliders A, B, C, and D on a high-precision linear guide, and respectively installing a four-dimensional optical adjustment frame, a five-dimensional optical adjustment frame A, a five-dimensional optical adjustment frame B, and a five-dimensional optical adjustment frame C on the high-precision sliders A, B, C, and D, precise adjustment of the distance between each adjustment frame can be achieved, thus meeting the requirements of precise adjustment. Installing the laser access head in the mounting hole at the center of the four-dimensional optical adjustment frame can achieve displacement adjustment of the laser access head in the tilted Y angle, tilted Z angle, translational X direction, and translational Y direction, and further flexibly adjust the output angle of the laser emitted by the laser access head according to different working conditions; after respectively installing lenses in the five-dimensional optical adjustment frame A, the five-dimensional optical adjustment frame B, and the five-dimensional optical adjustment frame C, displacement adjustment of the installed lens in the tilted Y angle, tilted Z angle, translational X direction, translational Y direction, and translational Z direction can be achieved according to different requirements. Then, by coordinating the adjustment of the position of the corresponding high-precision slider, adjustment of the spot size and focal depth before welding can be achieved. Specifically, an interval adjustment of the spot diameter from 10 microns to 200 microns can be achieved, and at the same time, the focal length corresponding to different spots can be adjusted, thus meeting the welding requirements of different materials and processes. This device has good adjustment flexibility, can achieve adjustment of the spot diameter without replacing any lenses, and can also adjust the focal length corresponding to different spots.

[0039] As Figure 4 shown, first install the basic components of the laser welding device according to the assembly method of the present invention. The four-dimensional optical adjustment frame 3 installs the laser access head 1, and the laser beam source accessed by the laser access head 1 emits a laser beam with a wavelength of 2 microns, preferably a laser beam emitted by a fiber laser. The five-dimensional optical adjustment frame A 4, the five-dimensional optical adjustment frame B 5, and the five-dimensional optical adjustment frame C 6 respectively install plano-convex lens A 18, plano-convex lens B 19, and plano-convex lens C 20. The parameters of the plano-convex lenses are F1 = 100 mm, lens F2 = 50 mm, and lens F3 = 50 mm in sequence. By adjusting the distance d1 between the laser beam and the plano-convex lens A 18 = 50 mm, the distance d2 from the plano-convex lens A 18 to the plano-convex lens B 19 = 100 mm, and the distance from the plano-convex lens B 19 to the plano-convex lens C 20 from 120 mm to 150 mm, an adjustable spot radius from 10 microns to 200 microns can be achieved.

[0040] Simulate the optical path through the optical design software rezonator:

[0041] (1) Set d1 = 50 mm, d2 = 100 mm, d3 = 130 mm. The software simulates that the spot radius R is 100 microns and the depth of focus DOF is 5 mm (as Figure 5 ) to achieve a weld bead width of 200 microns for the welded sample PMMA (as Figure 6 ).

[0042] (2) Set d1 = 50 mm, d2 = 100 mm, d3 = 120 mm. The spot radius R simulated by the software is 60 microns, and the depth of focus DOF is 2 mm (as Figure 7 ), achieving a weld seam with a weld bead width of 120 microns for the welded PMMA sample (as Figure 8 ).

[0043] The spot emitted by this device has the characteristics of being quickly adjustable and having high precision. The spot data simulated by the software can be fully realized by this device, achieving convenient and fast adjustment while achieving precise adjustment.

[0044] As Figure 9 shown, in the present invention, through the combined design of optical components, the device can adjust the diameter of the incident laser spot 22 in the range of microns to sub - millimeters by only adjusting the distance between the lenses without replacing any lenses. At the same time, the depth of focus corresponding to different incident laser spots 22 can be adjusted. Through the optimized combination of the spot and the depth of focus, the effects of high transmittance of the laser to the upper - layer welding material and high absorption by the contact surface of the upper and lower - layer materials are achieved. When the laser is incident on the upper surface 21 of the upper - layer polymer material, the incident laser spot 22 is large enough to ensure that the upper surface 21 of the upper - layer polymer material does not absorb heat and deform, and there is enough energy transmitted to the contact surface 23 of the upper and lower - layer polymer materials. Near the contact surface 23 of the upper and lower - layer polymer materials, the laser spot is small enough to be absorbed by the materials near the contact surface 23 of the upper and lower - layer polymer materials, realizing the welding of the upper - layer polymer 24 and the lower - layer polymer 25, which can meet the requirements of non - deformation and high - precision welding of different types and different thicknesses of transparent polymer plates, and ensure a small weld seam width. It solves the problem of laser welding of thick transparent polymer plates, and by adjusting the distance between the plano - convex lenses of the welding device, it can meet the requirements of different welding processes for products with a set of welding devices.

Claims

1. A high-precision laser welding device with variable focal depth, comprising a laser access head (1), characterized in that, It further includes a welding plate (2), a high-precision linear guide rail (7), a limit frame (11), a high-precision slider A (8), a high-precision slider B (9), a high-precision slider C (10), a high-precision slider D (12), a four-dimensional optical adjustment frame (3), a five-dimensional optical adjustment frame A (4), a five-dimensional optical adjustment frame B (5), and a five-dimensional optical adjustment frame C (6); The length direction of the welding plate (2) extends along the left-right direction; The length direction of the high-precision linear guide rail (7) is consistent with the length direction of the welding plate (2), and it is fixedly connected to the upper end of the welding plate (2); Two limit frames (11) are respectively sleeved outside both ends of the high-precision linear guide rail (7), and their bottom ends are both fixedly connected to the upper end surface of the welding plate (2); The high-precision slider A (8), high-precision slider B (9), high-precision slider C (10), and high-precision slider D (12) are successively assembled and slid on the high-precision linear guide rail (7) from left to right; The four-dimensional optical adjustment frame (3), five-dimensional optical adjustment frame A (4), five-dimensional optical adjustment frame B (5), and five-dimensional optical adjustment frame C (6) are respectively fixedly installed on the high-precision slider A (8), high-precision slider B (9), high-precision slider C (10), and high-precision slider D (12); The five-dimensional optical adjustment frame A (4), five-dimensional optical adjustment frame B (5), and five-dimensional optical adjustment frame C (6) are respectively installed with plano-convex lens A (18), plano-convex lens B (19), and plano-convex lens C (20); The plano-convex lens A (18), plano-convex lens B (19), and plano-convex lens C (20) have a high transmittance for 1.9 - 2.1 μm band laser, the lens parameters are F1 = 100 mm, F2 = 50 mm, F3 = 50 mm in sequence, the distance d1 between the laser beam and the plano-convex lens A (18) is 50 mm, the distance d2 from the plano-convex lens A (18) to the plano-convex lens B (19) is 100 mm, and the distance from the plano-convex lens B (19) to the plano-convex lens C (20) is 120 mm - 150 mm; The laser access head (1) is installed in the mounting hole at the center of the four-dimensional optical adjustment frame (3), and the laser beam source accessed by the laser access head (1) is configured to emit a laser beam with a wavelength of 2 microns.

2. The high-precision laser welding device with variable focal depth according to claim 1, characterized in that The five-dimensional optical adjustment frame A (4), five-dimensional optical adjustment frame B (5), and five-dimensional optical adjustment frame C (6) are all AMM5-1A adjustment frames.

3. The high-precision laser welding device with variable focal depth according to claim 1 or 2, characterized in that The limit frame (11) is in an inverted U shape.

4. A high-precision laser welding device with variable focal depth according to claim 3, characterized in that, It further includes a positioning plate (15). The front side and the rear side of the middle part of the welding plate (2) each have an extension part (14) extending outward. A pair of positioning holes B (13) are respectively opened at both ends of the extension part (14) in the length direction; the length direction of the positioning plate (15) extends in the front-back direction, and multiple pairs of positioning holes A (16) are opened along the front-back direction. At the same time, fixing holes are also opened on the positioning plate (15); each pair of positioning holes A (16) is arranged to be adapted to a pair of positioning holes B (13); the positioning plate (15) is disposed in a fitting manner below the middle part of the welding plate (2), and is fixedly connected by positioning bolts passing through each pair of positioning holes A (16) and a pair of positioning holes B (13).

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