A dual-beam laser machining device

Abstract

The application belongs to the field of laser processing, and discloses a double-beam laser processing device, wherein the laser device comprises a double-beam laser head, a special wedge prism is used to convert a single laser beam output by a conventional laser into a rotatable double laser beam, and a conventional wedge prism is further used to output a composite track double-beam, so that the output laser beam can be used for circular ring-shaped, circular dot-shaped and other processing requirements, and the processing efficiency and processing quality can be improved.

Description

Technical Field

[0001] This invention belongs to the field of laser processing, and more specifically, relates to a dual-beam laser processing device. Background Technology

[0002] Welding of dot-shaped, elliptical, or circumferential welds is a common welding requirement in the 3C industry, new energy batteries, and automotive bodies. Precision laser welding, laser scanning welding, and laser spiral welding are widely used to address these needs, and laser processing devices based on scanning galvanometers are typically used to implement these methods. Existing scanning galvanometer laser heads usually use two sets of galvanometers to control a single laser beam to achieve scanning of the area to be processed along a preset trajectory, thereby obtaining the desired processing effect. For applications involving materials with coatings on their surfaces or combinations of dissimilar materials, single-laser-beam galvanometer scanning welding cannot effectively ensure the uniformity of the weld, thus affecting the final weld quality. In the welding of large-size dot welds, the single-laser-beam galvanometer scanning path is long, requiring a long time to complete the weld point; or, when the single-point welding time is reduced, the weld quality decreases. Summary of the Invention

[0003] To improve the quality and efficiency of laser welding of dot-shaped welds, this invention provides a dual-beam laser processing device, the specific solution of which is as follows:

[0004] The dual-beam laser processing device includes a laser head and a motion mechanism. The laser head is used to connect to a laser and convert the single laser beam output by the laser into a dual laser beam. The motion mechanism is used to fix the position of the laser head and / or adjust the position of the laser head to the position to be processed.

[0005] Specifically, the laser head includes a collimation unit, a beam splitting unit, and a focusing unit; the beam splitting unit includes a specially designed wedge prism, one side of which is a plane 11 perpendicular to the optical axis, and the other side of which includes two non-coplanar and non-parallel planes; when the collimated parallel laser beam passes through the wedge prism, two parallel beams with different deflection directions are obtained, and after focusing, two focal points with different positions on the focal plane are obtained; the laser beams forming the two focal points act on the part to be processed and continue for a period of time to heat the material to form a processing area.

[0006] In a preferred embodiment, the other side of the specially designed wedge prism has two surfaces, one of which is an inclined plane 12 and the other is a plane 13 parallel to the plane 11. The plane 13 intersects the inclined plane 12 with a straight line. The plane 13 deflects part of the collimated laser beam with zero deflection, ultimately forming a focal point 21 located on the optical axis. The inclined plane 12 deflects part of the collimated laser beam, ultimately forming a focal point 22 that is off the optical axis and coplanar with the focal point 21.

[0007] The beam splitting unit also includes a driving mechanism to drive the specially designed wedge prism to rotate continuously, so that the focal point 22 rotates continuously around the focal point 21; when the laser beam forming the focal point 21 is fixedly applied to the part to be processed, the laser beam forming the focal point 22 rotates and applies to the part to be processed.

[0008] Optionally, the drive mechanism is a hollow direct-drive torque motor;

[0009] Optionally, the maximum rotational speed of the wedge prism is 10,000 revolutions per minute.

[0010] Optionally, the maximum rotational speed of the wedge prism is 6000 rpm.

[0011] Optionally, the processing area generated by the rotating action of the laser beam forming the focal point 22 on the part to be processed is eventually merged with the processing area generated by the fixing action of the laser beam forming the focal point 21, becoming a point-shaped or circular processing area.

[0012] Preferably, the distance by which the focal point 22 deviates from the optical axis does not exceed four times the sum of the diameters of the focal points 21 and 22.

[0013] In another preferred embodiment, the other side of the inclined surface 12 of the specially designed wedge prism is an inclined surface 14; the inclined surface 14 intersects the inclined surface 12 in a straight line; the inclined surface 12 and the inclined surface 14 deflect a portion of the collimated laser beam in opposite directions, and the two deflected laser beams eventually form focal points 22 and 23 off the optical axis on the focal plane, respectively;

[0014] Optionally, the inclined plane 12 and the inclined plane 14 have the same wedge angle;

[0015] When the specially designed wedge prism is driven to rotate continuously, the two laser beams forming focal point 22 and focal point 23 rotate synchronously around the optical axis and act on the part to be processed.

[0016] Optionally, the two rotating laser beams form a ring-shaped processing area;

[0017] Optionally, the distance between the focal points 22 and 23 and the optical axis does not exceed four times the sum of the diameters of the light spots of the focal points 22 and 23, forming a dot-shaped processing area.

[0018] Optionally, the wedge angle formed by the inclined plane 14 and the plane 11 is smaller than the wedge angle formed by the inclined plane 12 and the plane 11. Preferably, the distance of the focal point 22 from the optical axis does not exceed 8 times the sum of the diameters of the focal points 22 and 23, and the distance of the focal point 23 from the optical axis does not exceed 4 times the sum of the diameters of the focal points 22 and 23.

[0019] In yet another preferred embodiment, the laser head further includes another conventional wedge prism located after the specially designed wedge prism along the optical path, causing the two laser beams output by the specially designed wedge prism to deflect.

[0020] Optionally, the specially designed wedge prism and the conventional wedge prism rotate independently around the optical axis, so that the laser beam output by the specially designed wedge prism, which deviates from the optical axis, acts on the part to be processed in a curved trajectory including a circular trajectory, and the laser beam parallel to the optical axis acts on the part to be processed in a circular trajectory. The two laser beams work together to form the processing area.

[0021] Optionally, the specially designed wedge prism rotates in the same direction but at a different speed than the conventional wedge prism, so that the laser beam output by the specially designed wedge prism, which deviates from the optical axis, ultimately acts on the part to be processed in a spiral trajectory.

[0022] Optionally, the thicker end of the specially designed wedge prism slope 12 is located in the same orientation as the thicker end of the conventional wedge prism, and the slope of the conventional wedge prism faces the output surface of the specially designed wedge prism, with a gap between them;

[0023] Optionally, the conventional wedge prism has a wedge angle of the same size as the inclined plane 12;

[0024] Optionally, the conventional wedge prism has a wedge angle of the same size as the inclined plane 14, but smaller than the wedge angle of the inclined plane 12.

[0025] In another preferred embodiment, the intersection line of the two non-coplanar and non-parallel surfaces on the other side of the wedge prism is offset from the optical axis, so that the laser beam area passing through the two surfaces is significantly different. Preferably, the passing area of ​​the laser beam that is far from the optical axis is not less than 60% and not more than 80% of the total laser beam area.

[0026] Optionally, the intersection of the two non-coplanar and non-parallel surfaces on the other side of the wedge prism is a smooth transition.

[0027] Optionally, the wedge angle of any inclined surface of the specially designed wedge prism does not exceed 5°, and the wedge angle of the conventional wedge prism does not exceed 5°;

[0028] Optionally, the processing area is ultimately an annular, circular, or elliptical weld area.

[0029] In another preferred embodiment, the laser device includes multiple laser heads, and the motion mechanism controls the multiple laser heads simultaneously, so that the multiple laser heads can act on different parts to be processed simultaneously or separately, thereby improving the overall processing efficiency of the device.

[0030] Optionally, the number of the plurality of laser heads is 2 to 6, and the motion mechanism can simultaneously control the plurality of laser heads to adjust their positions respectively, so as to achieve efficient processing of a large number of welds.

[0031] In the above scheme, the collimation unit of the laser head preferably uses a single aspherical lens for laser beam collimation, and can optionally use a multi-spherical lens collimation lens group: such as a Galilean two-piece collimation lens group or a three-piece variable focus collimation lens group.

[0032] Optionally, when the wedge angles of all wedge prisms are less than 1°, the focusing unit uses a single aspherical lens for focusing;

[0033] Preferably, the focusing unit uses a multi-lens group for focusing, such as a meniscus negative-positive-positive three-lens group.

[0034] By adopting the above-described technical solution of the present invention, the following beneficial effects can be obtained:

[0035] 1. The dual-beam laser processing device provided by the present invention is specifically designed for ring or point processing needs, breaking the application limitations of conventional dual-beam lasers. Compared with single-laser beam scanning galvanometer processing, the device of the present invention provides dual heat source synchronous processing to improve processing efficiency, and improves processing quality through laser beam rotation.

[0036] 2. In the solution provided by the present invention, when the laser beam whose focus is off the optical axis rotates around the laser beam whose focus is on the optical axis, the laser beam whose focus is on the optical axis acts fixedly on the processing part, causing the material to melt rapidly and spread to the surrounding area; the laser beam whose focus is off the optical axis gradually melts the material during the rotation process; after the melting areas of the two laser beams merge, the rotating laser beam plays the role of stirring the molten pool, which increases the uniformity of element distribution in the processing area, promotes the discharge of pores inside the molten pool, and improves the overall processing quality, which is suitable for spot weld processing.

[0037] 3. In the solution provided by this invention, when the focal points of both laser beams deviate from the optical axis by the same distance, the two heat sources rotate in symmetrical positions, which is suitable for processing annular welds. The dual heat source processing efficiency is high, and the welding quality is improved through mutual preheating and post-processing. When the focal points of the two laser beams deviate from the optical axis by a larger distance than one smaller distance, they each produce circular welds that expand outwards and eventually merge, which is suitable for processing larger-sized spot welds.

[0038] 4. In the solution provided by the present invention, when the two beams pass through another wedge prism and the two wedge prisms rotate independently, unlike conventional Risley prisms, the present invention has two laser beams, which can realize that one beam processes in a spiral trajectory and the other beam processes in a circular trajectory; or both laser beams process in a spiral trajectory, with one beam from the outside to the inside and the other from the inside to the outside. Compared with a single laser beam, this can effectively improve the processing quality of the coating material.

[0039] 5. In the solution provided by the present invention, when the motion mechanism controls multiple laser heads to process synchronously, the overall processing efficiency of the device is significantly increased. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of a dual-beam laser processing device, including a dual-beam laser head and a motion mechanism. The laser head is connected to a laser and outputs dual laser beams. The motion mechanism can carry the laser head to move in the X, Y, and Z directions.

[0041] Figure 2 A schematic diagram of a dual-beam laser head device with one focal point on the optical axis and the other focal point off the optical axis.

[0042] Figure 3 Schematic diagram of a dual-beam laser head scheme where the laser beam with its focal point off-axis rotates around the optical axis.

[0043] Figure 4 Schematic diagram of a dual-beam laser head device in which two laser beams with their focal points offset from the optical axis by the same distance rotate synchronously and continuously.

[0044] Figure 5 Schematic diagram of a dual-beam laser head device in which two laser beams with different focal points deviating from the optical axis rotate synchronously and continuously.

[0045] Figure 6 A schematic diagram of a dual-beam laser head device in which one laser beam scans in a spiral pattern from a larger outer diameter and the other laser beam scans in a circular pattern from a smaller inner diameter.

[0046] Figure 7 A schematic diagram of a dual-beam laser head device in which one laser beam scans inward spiral from a larger outer diameter and the other laser beam scans outward spiral from a smaller inner diameter.

[0047] Figure 8 A schematic diagram of a dual-beam laser head scheme where the laser beam with its focal point on the optical axis has lower laser energy, and the laser beam with its focal point off the optical axis has higher laser energy.

[0048] Figure 9 A schematic diagram of a dual-beam laser head scheme where the laser beam with its focal point closer to the optical axis has lower energy, and the laser beam with its focal point farther from the optical axis has higher energy.

[0049] Figure 10 Schematic diagram of a meniscus-shaped negative-positive-positive three-element focusing lens group

[0050] Figure 11 Schematic diagram of a two-piece collimating lens group

[0051] Figure 12 Schematic diagram of a three-element variable focus collimating lens group

[0052] Figure 13 Schematic diagram of a dual-beam laser processing device that controls two dual-beam laser heads for motion mechanism Detailed Implementation

[0053] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings.

[0054] The term "embodiment" as used herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment herein. The phrase appearing in various places in the specification does not necessarily refer to the same embodiment, nor is it limited to mutually exclusive, independent, or alternative embodiments. Those skilled in the art will understand that the embodiments herein can be combined with other embodiments without structural conflict.

[0055] This invention provides different schemes for a dual-beam laser processing device, which includes a laser head and a motion mechanism. The laser head is used to connect to a laser and convert the single laser beam output by the laser into a dual laser beam. The motion mechanism is used to fix the position of the laser head and / or adjust the position of the laser head to the welding position. The laser head device includes a collimation unit, a beam splitting unit, and a focusing unit. The collimation unit is connected to the laser via an interface and adjusts the diverging laser beam input from the laser into a collimated parallel beam. The beam splitting unit includes a specially designed wedge prism, one side of which is a plane perpendicular to the optical axis, and the other side includes two non-coplanar and non-parallel planes. When the collimated parallel laser beam passes through the wedge prism, it will be deflected into two parallel beams with different directions. The focusing unit focuses the two parallel beams with different incident angles to obtain two focal points with different positions on the focal plane, that is, the laser head device converts a single laser beam into a dual laser beam. The two laser beams forming the two focal points act simultaneously on the part to be processed for a period of time to achieve material processing. The dual-beam laser processing device is preferably used in applications requiring ring-shaped or point-shaped processing, such as welding ring-shaped or dot-shaped welds. According to the solution provided by the present invention, the dual-beam laser head device can output in different dual-beam combinations, thereby achieving processing in different ways to meet processing requirements such as different plate thickness combinations and target dimensions.

[0056] Example 1

[0057] like Figure 2 As shown, the diverging beam of laser 1 passes sequentially through the collimating unit of the laser head device, which includes a single aspherical collimating lens 2; the beam splitting unit, which includes a single specially designed wedge prism 3; and the focusing unit, which includes a single aspherical focusing lens 4. The single aspherical collimating lens 2 in the collimating unit adjusts the diverging beam into a parallel laser beam; the specially designed wedge prism 3 in the beam splitting unit outputs the single parallel laser beam as two parallel laser beams with different directions; and the single aspherical focusing lens 4 in the focusing unit focuses the two parallel laser beams respectively, obtaining two separate focal points 21 and 22 on the focal plane. In this embodiment, the side of the specially designed wedge prism 3 facing the incident parallel laser beam is a plane 11 perpendicular to the optical axis, and the other side includes an inclined plane 12 and a plane 13. The plane 13 is parallel to the plane 11, and the thinner side of the inclined plane 12 intersects the plane 13 in a straight line, with the intersection line passing through the optical axis. The incident laser beam is divided into two parts of equal or comparable area. The inclined plane 12 has a wedge angle greater than 0° and not exceeding 5°, causing part of the laser beam to deflect before exiting and being focused to obtain a focal point 22 off the optical axis; the remaining laser beam passes through the plane 13 perpendicular to the optical axis without deflection and is focused to obtain a focal point 21 located on the optical axis. The distance of focal point 22 from the optical axis depends on the wedge angle of the inclined plane 12 and the focal length of the aspherical focusing lens 4, and can be estimated using the formula: S≈f*(n-1)*A, where S is the distance of the focal point off the optical axis, f is the focal length of the focusing lens, n is the refractive index of the lens material at the corresponding laser wavelength, and A is the value of the wedge angle corresponding to the wedge prism exiting the inclined plane 12 converted to rad. In this embodiment, the center distance between the light spots of focal point 22 and focal point 21 is also S.

[0058] Optionally, the laser 1 outputs a 1064nm wavelength laser. The collimating lens 2, wedge prism 3, and focusing lens 4 are all made of fused silica material, with a corresponding refractive index n of approximately 1.4496. When the wedge angle of the inclined plane 12 is 1.5° ≈ 0.02618 rad, the distance S ≈ 0.01177 * f from the optical axis of the focal point 22. When the focal length of the focusing lens 4 is designed to be 200mm, the focal point 22 will deviate from the optical axis by approximately 2.354mm; when the focal length of the focusing lens 4 is designed to be 300mm, the focal point 22 will deviate from the optical axis by approximately 3.531mm. Depending on the requirements, the wedge angle of the inclined plane 12 of the wedge prism 3 and the focal length of the focusing lens 4 can be selectively designed to obtain a focal point 22 with a specific distance from the optical axis. When the wedge angle of the inclined plane 12 does not exceed 5° and the focal length of the focusing lens 4 is 100~300mm, a focal point 22 with a distance greater than 0mm and less than 12mm from the optical axis can be obtained. In a specific example, the spot diameters of focal points 21 and 22 are 0.6 mm, and the distance of focal point 22 from the optical axis does not exceed 4.8 mm.

[0059] Preferably, when the wedge angle of the inclined plane 12 exceeds 1°, the focusing unit uses, as shown in the example below. Figure 10 The three-element lens group, consisting of negative meniscus lens 41, positive meniscus lens 42, and positive meniscus lens 43, replaces the single focusing lens 4 to focus the laser beam.

[0060] Example 2

[0061] like Figure 3 As shown, similar to Embodiment 1, the difference is that the beam-splitting unit of the laser head device also includes a rotation mechanism, preferably a hollow torque motor, to drive the specially designed wedge prism 3 to rotate. During the rotation of the specially designed wedge prism 3, the inclined surface 12 and the plane 13 rotate together, causing the laser beams passing through the two exit surfaces to also rotate. After final focusing, the focal point 21 located on the optical axis remains unchanged, while the focal point 22, which deviates from the optical axis, rotates around the focal point 21 at the same speed as the specially designed wedge prism 3. The specially designed wedge prism 3 can be selected with a maximum rotation speed of 10,000 rpm, and preferably not exceeding 6,000 rpm during the dual-beam laser processing. According to the data of Example 1, when the wedge angle of the inclined plane 12 is 1.5° and the focal length is 200mm, the focal point 22 rotates in a circular trajectory with a radius of 2.354mm. When the focal length is 300mm, the focal point 22 rotates in a circular trajectory with a radius of 3.531mm. Preferably, the rotation radius of the focal point 22 does not exceed 4 times the sum of the diameters of the focal spot 21 and the focal spot 22.

[0062] Example 3

[0063] like Figure 4 As shown, similar to Embodiment 2, the difference is that the plane 13 on the same side as the inclined plane 12 in the special wedge prism 3 is replaced by the inclined plane 14. The wedge angle of the inclined plane 14 is opposite to the wedge angle of the inclined plane 12, that is, the thinner side of the inclined plane 14 intersects with the thicker side of the inclined plane 12, and the line of intersection of the two passes through the optical axis. In this embodiment, the wedge angle of the inclined plane 14 is the same as that of the inclined plane 12, ultimately obtaining a focal point 23 that is offset from the optical axis by the same distance as the focal point 22. The positions of the two are symmetrically distributed relative to the optical axis. During the continuous rotation of the specially designed wedge prism 3, the focal points 22 and 23 rotate continuously relative to each other. The rotation trajectories of the two focal points are both circles with a radius of S, and the distance between the two focal points is 2S. For example, when the wedge angles of the inclined planes 12 and 14 are both 3° and the focal length of the focusing lens 4 is 300mm, the center distance between the focal points 22 and 23 is 14.125mm, and the corresponding two laser beams perform ring processing; when the wedge angles are both 1.5° and the focal length of the focusing lens is 200mm, the center distance between the focal points 22 and 23 is 4.708mm, and the corresponding two laser beams perform dot-shaped processing.

[0064] Preferably, when the wedge angles of inclined plane 12 and inclined plane 14 each exceed 1°, the focusing unit uses, as shown in the example below. Figure 10 The three-element lens group, consisting of negative meniscus lens 41, positive meniscus lens 42, and positive meniscus lens 43, replaces the single focusing lens 4 to focus the laser beam.

[0065] Example 4

[0066] like Figure 5 As shown, similar to Embodiment 3, except that the inclined plane 14 has a smaller wedge angle than the inclined plane 12, and the distance of the focal point 23 from the optical axis is less than the distance of the focal point 22 from the optical axis. During the continuous rotation of the special wedge prism 3, the focal points 22 and 23 rotate around two circular trajectories, one large and one small. The radii of the two circular trajectories are the distances of the focal points 22 and 23 from the optical axis, respectively, and the distance between the focal points 22 and 23 is the sum of their respective distances from the optical axis. For example, if the wedge angle of the inclined plane 12 is 3°, the wedge angle of the inclined plane 14 is 1.5°, and the focal length of the focusing lens 4 is 200mm, then the rotation trajectory of the focal point 22 is a circle with a radius of 4.708mm, the rotation trajectory of the focal point 23 is a circle with a radius of 2.354mm, and the distance between the two focal points is 7.062mm. When the diameter of the focal spot is 0.6mm, the two rotating laser beams act on the part to be processed, ultimately forming a dot-shaped weld with a diameter of approximately 10mm.

[0067] Preferably, when either the wedge angle between the inclined plane 12 and the inclined plane 14 exceeds 1°, the focusing unit uses, as shown in the example below. Figure 10 The three-element lens group, consisting of negative meniscus lens 41, positive meniscus lens 42, and positive meniscus lens 43, replaces the single focusing lens 4 to focus the laser beam.

[0068] Example 5

[0069] like Figure 6As shown, similar to Embodiment 2, the difference is that the beam splitting unit of the laser head also includes a conventional wedge prism 5. The two laser beams output from the specially designed wedge prism 3 enter from the inclined surface 15 of the conventional wedge prism 5 and exit from the plane 16, causing the two laser beams to deflect. When the specially designed wedge prism 3 and the conventional wedge prism 5 rotate independently, according to the rotational output characteristics of the Risley prism pair, the deflected laser beam output from the inclined surface 12 can ultimately act on the part to be processed with a circular, rose curve, spiral, or other trajectory; at the same time, the parallel laser beam output from the plane 13 ultimately acts on the part to be processed with a circular trajectory. Optionally, the inclined plane 12 and the inclined plane 15 have the same wedge angle, and their thicker sides face the same direction. The specially made wedge prism 3 rotates in the same direction as the conventional wedge prism 5, and the rotation speed of the specially made wedge prism 3 is lower than that of the conventional wedge prism 5. Finally, the laser beam of the output focal point 22 acts on the part to be processed from the outside to the inside in a spiral trajectory. During this process, the laser beam of the output focal point 21 rotates continuously along a circular trajectory and acts on the part to be processed. Optionally, during the processing, the processing time does not exceed the time it takes for the laser beam to complete the scanning of the entire spiral from the outside to the inside.

[0070] Preferably, when either the wedge angle between the inclined plane 12 and the inclined plane 15 exceeds 1°, the focusing unit uses, as shown in the example below. Figure 10 The three-element lens group, consisting of negative meniscus lens 41, positive meniscus lens 42, and positive meniscus lens 43, replaces the single focusing lens 4 to focus the laser beam.

[0071] Example 6

[0072] like Figure 7 As shown, similar to Embodiment 5, the difference is that the output surfaces of the specially designed wedge prism 3 are inclined planes 12 and 14. According to the example of Embodiment 5, the laser beam of the output focal point 23 acts on the part to be processed in a spiral trajectory from the inside to the outside. When the inclined plane 14 has a wedge angle of the same size as the inclined plane 12, the outer diameter of the spiral of the two laser beams from the outside to the inside is equal to the outer diameter of the spiral from the inside to the outside. When the inclined plane 14 has a wedge angle smaller than that of the inclined plane 12, the outer diameter of the spiral of the laser beam from the inside to the outside is smaller than the outer diameter of the spiral from the outside to the inside.

[0073] Preferably, when any wedge angle of inclined plane 12, inclined plane 14, and inclined plane 15 exceeds 1°, the focusing unit uses as follows: Figure 10 The three-element lens group, consisting of negative meniscus lens 41, positive meniscus lens 42, and positive meniscus lens 43, replaces the single focusing lens 4 to focus the laser beam.

[0074] Example 7

[0075] like Figure 8As shown, similar to Embodiment 2, the difference is that the straight line intersecting the inclined plane 12 and the plane 13 deviates from the optical axis, causing the area of ​​the incident laser beam passing through one of the planes to be larger, resulting in two laser beams with significantly different output energy. In this embodiment, the area of ​​the laser beam passing through the plane 13 is smaller than the area of ​​the laser beam passing through the inclined plane 12. When the specially designed wedge prism 3 rotates continuously, the focal point 21 with lower energy is fixed on the part to be processed, while the focal point 22 with higher energy rotates and acts on the part to be processed, thus obtaining a more balanced processing effect.

[0076] Example 8

[0077] like Figure 9 As shown, similar to Embodiment 4, the difference is that the intersection line of the inclined plane 12 and the inclined plane 14 deviates from the optical axis, resulting in a larger area of ​​the laser beam passing through one of the planes, ultimately outputting two laser beams with significant energy differences. In this embodiment, the incident area of ​​the laser beam passing through the inclined plane 12 is larger than that of the laser beam passing through the inclined plane 14. When the wedge prism 3 rotates continuously, the focal point 23 with lower energy rotates with a smaller radius, and the focal point 22 with higher energy rotates with a larger radius, thus achieving a more balanced processing effect.

[0078] In addition to the above embodiments, in the dual-beam laser head solution of the present invention, the collimation unit of the laser head device may use a multi-element spherical lens instead of the single-element aspherical lens. For example, using... Figure 11 The meniscus negative lens with its concave surface facing the laser incident direction and the biconvex positive lens shown are used as a collimating lens group; alternatively, a meniscus negative lens that moves along the optical axis can be added in the middle, and the linkage of the biconvex positive lens can be adjusted to make the collimated parallel beam diameter adjustable, as shown in the collimating lens group. Figure 12 As shown, this results in a dual-beam laser processing device with a variable focal diameter.

[0079] Example 9

[0080] like Figure 13 As shown, the dual-beam laser processing apparatus of the present invention includes multiple laser heads. The motion mechanism simultaneously controls the multiple laser heads to act on different processing areas, or controls another laser head that has completed processing to move to the next processing area while one laser head is processing. Optionally, the multiple laser heads can each adopt different dual-beam laser head schemes to address different types of processing needs.

[0081] The purpose of the above embodiments is to provide a further detailed description of the present invention in conjunction with the accompanying drawings, so that those skilled in the art can understand the technical concept of the present invention. Within the scope of the claims of the present invention, any improvements, optimizations, or equivalent substitutions made to the structure or method of the present invention, as well as combinations of implementation methods in different embodiments without causing a conflict of principle, all fall within the protection scope of the present invention.

Claims

1. A dual-beam laser processing device, characterized in that, It includes a laser head and a motion mechanism. The laser head is used to connect to a laser and convert the single laser beam output by the laser into a dual laser beam. The motion mechanism is used to fix the position of the laser head and / or adjust the position of the laser head to the part to be processed. Specifically, the laser head includes a collimation unit, a beam splitting unit, and a focusing unit; the beam splitting unit includes a specially designed wedge prism, one side of which is a plane 11 perpendicular to the optical axis, and the other side of which includes two non-coplanar and non-parallel planes; when the collimated parallel laser beam passes through the wedge prism, two parallel beams with different deflection directions are obtained, and after focusing, two focal points with different positions on the focal plane are obtained; The laser beams that form the two focal points act on the area to be processed and continue for a period of time to heat the material and form the processing zone.

2. The dual-beam laser processing apparatus as described in claim 1, characterized in that, The special wedge prism has two faces on the other side, one of which is an inclined plane 12 and the other is a plane 13 parallel to the plane 11. The plane 13 intersects the inclined plane 12 with a straight line. The plane 13 deflects part of the collimated laser beam with zero deflection, ultimately forming a focal point 21 located on the optical axis. The inclined plane 12 deflects part of the collimated laser beam, ultimately forming a focal point 22 that is off the optical axis and coplanar with the focal point 21. The beam splitting unit also includes a driving mechanism to drive the specially designed wedge prism to rotate continuously, so that the focal point 22 rotates continuously around the focal point 21; when the laser beam forming the focal point 21 is fixedly applied to the part to be processed, the laser beam forming the focal point 22 rotates and applies to the part to be processed.

3. The dual-beam laser processing apparatus as described in claim 2, characterized in that, The distance by which the focal point 22 deviates from the optical axis does not exceed four times the sum of the diameters of the focal points 21 and 22.

4. The dual-beam laser processing apparatus as described in claim 2, characterized in that, The other side of the inclined surface 12 of the specially designed wedge prism is the inclined surface 14; the inclined surface 14 intersects the inclined surface 12 in a straight line; the inclined surface 12 and the inclined surface 14 deflect a portion of the collimated laser beam in opposite directions, and the two deflected laser beams finally form focal points 22 and 23 off the optical axis on the focal plane, respectively. The inclined plane 12 and the inclined plane 14 have the same wedge angle; When the specially designed wedge prism is driven to rotate continuously, the two laser beams forming focal points 22 and 23 rotate synchronously around the optical axis and act on the part to be processed.

5. The dual-beam laser processing apparatus as described in claim 4, characterized in that, The wedge angle formed by the inclined plane 14 and the plane 11 is smaller than the wedge angle formed by the inclined plane 12 and the plane 11.

6. The dual-beam laser processing apparatus as described in claims 1-5, characterized in that, The laser head also includes another conventional wedge prism, which is located after the specially designed wedge prism along the optical path. The specially designed wedge prism and the conventional wedge prism rotate independently around the optical axis, so that the laser beam output by the specially designed wedge prism, which deviates from the optical axis, acts on the part to be processed in a curved trajectory including a circular trajectory, while the laser beam parallel to the optical axis acts on the part to be processed in a circular trajectory. The two laser beams work together to form the processing area.

7. The dual-beam laser processing apparatus as described in claim 6, characterized in that, The specially designed wedge prism rotates in the same direction at a different speed than the conventional wedge prism, so that the laser beam output by the specially designed wedge prism, which deviates from the optical axis, ultimately acts on the part to be processed in a spiral trajectory.

8. The dual-beam laser processing apparatus as described in claims 1 to 7, characterized in that, The intersection line of the two non-coplanar and non-parallel surfaces on the other side of the wedge prism is off-axis, so that the laser beam area passing through the two surfaces is significantly different. Preferably, the area of ​​the laser beam that is far off-axis is not less than 60% and not more than 80% of the total laser beam area.

9. The dual-beam laser processing apparatus as described in claims 1 to 8, characterized in that, The wedge angle of any inclined surface of the specially made wedge prism does not exceed 5°, the wedge angle of the conventional wedge prism does not exceed 5°, and the processing area is ultimately an annular, circular, or elliptical weld area.

10. The dual-beam laser processing apparatus as described in claims 1 to 9, characterized in that, The laser device includes multiple laser heads, and the motion mechanism controls the multiple laser heads simultaneously, so that the multiple laser heads can act on different parts to be processed at the same time or separately, thereby improving the overall processing efficiency of the device.

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