Laser rotary cutting machining system capable of increasing depth-diameter ratio

Abstract

The utility model discloses a laser rotary cutting machining system capable of increasing the depth-diameter ratio, and belongs to the technical field of laser machining optical design. The laser rotary cutting machining system comprises a laser, a beam expanding system, a light-transmitting rotating system, a rotary cutting system and a focusing system which are arranged in sequence, the light-transmitting rotating system comprises a light-transmitting mirror and a rotating mechanism, the light-transmitting mirror is arranged in the rotating mechanism, a rotating shaft of the light-transmitting mirror coincides with an optical axis of emergent light of the beam expanding system, and a shading structure is arranged on the light-transmitting mirror. The shading structure is adhered and fixed on the light-transmitting mirror, the shading structure is used for shading one half of incident light of the light-transmitting mirror in the direction perpendicular to the optical axis of the shading structure, the rotating speed of the light-transmitting mirror is the same as that of emergent light of the rotary cutting system, and meanwhile, when the rotary cutting system and the light-transmitting rotating system are in the initial state, the rotating speed of the emergent light of the rotary cutting system is the same as that of the light-transmitting rotating system. And one half of the part close to the rotating shaft is reserved. According to the design, not only is the depth-diameter ratio effectively improved, but also the machining quality is ensured.

Description

TECHNICAL FIELD

[0001] The utility model relates to laser processing optical design technical field especially relates to a laser rotary cutting processing system of can promote deep diameter ratio. BACKGROUND

[0002] Laser processing is a kind of precision efficient non-contact processing technology, is widely used in modern manufacturing, especially in metal plate cutting, precision drilling and three-dimensional micro-nano structure manufacturing etc. However, in the actual operation process, laser processing often appears the problem that the taper exists in the machining hole or cutting surface, that is, the hole diameter processed is inconsistent from top to bottom size, or the cutting surface presents the taper feature of wide upper narrow lower or narrow upper wide lower. This taper phenomenon directly affects the quality and precision of the workpiece, and restricts its application potential in high-end manufacturing field.

[0003] There are mainly two reasons for the emergence of such processing taper phenomenon:

[0004] The first is process factor. Laser beam focuses after optical system to form a focus area with high energy density, and the difference of focus position will lead to the difference of energy distribution, with the change of focus along the processing depth direction, energy density changes, causes the material removal rate at different depths to be different, thereby producing taper. In addition, the beam quality of laser, focal length, machine tool precision and stability, process parameter selection, workpiece material and thickness etc. all have direct influence on laser processing taper, but these are not the root cause of processing taper.

[0005] The second is optical factor. The shape of focused Gaussian beam gradually evolves into conical beam in the diffusion propagation process, reaches the narrowest state on the focal plane, at this time, the spot size is smallest and the energy density is highest. When far away from the focal plane, the beam will re-diverge again, leading to the energy distribution no longer concentrated. Therefore, when the focused beam irradiates to the material surface and tries to penetrate into the material interior, due to the influence of absorption and reflection of the edge part of laser on the material surface layer, the so-called "light blocking" effect appears. In this way, the beam energy gradually decays with the degree of its penetration into the material, cannot uniformly act on each depth layer of the material, causes the phenomenon that the middle region is more easily affected by laser compared with the peripheral region, and further makes the material processing region form taper morphology in the vertical direction. It can be seen that this factor is the root cause of taper.

[0006] There are many solutions and technical means to solve the problem of laser processing taper. For example: through precise control of laser output energy, using multi-pass low energy scanning or short focal length focusing, the taper can be reduced to a certain extent; using dynamic focusing system, the laser focal point changes with the processing depth in real time, keeps the energy distribution relatively constant, realizes more uniform material removal; improve the numerical control system, combined with high precision servo drive and closed loop feedback system, ensure the stability of the laser beam path, improve the overall dynamic performance of the machine tool; using new optical design, realize the fine control of beam shaping and energy distribution, reduce the taper. However, the above technologies are improvements for the first reason of taper, although they can improve the taper problem to a certain extent, but cannot completely eliminate the taper.

[0007] For the root cause of taper, rotary cutting is an effective solution. This technology controls the deflection angle of the focused beam to form an acute angle with the processing surface. By rotating such an inclined focused beam, it can be ensured that the outer edge of the focused laser beam will not come into contact with the wall of the processing hole during processing, avoiding the blocking of light by the hole wall, thereby perfectly solving the problem of processing taper caused by focusing effect. The main implementation methods include dynamic control of the relative attitude of the beam and the sample, use of a rotating prism system to guide laser deflection, use of a five-axis galvanometer to precisely control the laser path, and a combination of a galvanometer and a 4f optical system. Among them, Figure 4 The optical path diagram of the rotary cutting system combining the galvanometer and the 4f optical system,

[0008] However, the depth-diameter ratio of non-taper processing that can be achieved by rotary cutting is limited. When the focal plane rises to the vicinity of the position where the beam passes through the optical axis, the beam on the other side of the optical axis will pass through the optical axis again, causing the blocking effect. At this time, the rotary cutting processing capability reaches the limit. The depth-diameter ratio of the rotary cutting system is generally 10:1, and some schemes can reach 20:1. However, for increasingly complex and demanding applications, it is necessary to further improve the depth-diameter ratio of the system.

[0009] According to the principle of rotary cutting, the rotary cutting system can control the position and tilt angle of the focused laser beam exit by deflection and rotation of the beam, so that the beam is tilted and focused towards the direction close to its rotation axis, and finally focused on the opposite side after passing through the rotation axis. If such a beam is used to process materials, as the depth increases, the beam will shrink towards the optical axis. That is, the surface of the material will not block the beam, completely eliminating the cause of taper. However, as the depth further increases to the position where the beam passes through its rotation axis, the projection of the beam at this position covers half of the processing area. Subsequently, the beam will pass through its rotation axis and begin to affect the opposite side. From this time to the reappearance of the light blocking phenomenon, the depth of the laser feed determines the final depth-diameter ratio.

[0010] From the above analysis, the divergence degree of the light beam after leaving the focal point is closely related to the laser feed depth, if the divergence degree is small, the light beam can have a larger feed space after passing through its rotation axis, in the limit case, the feed depth can be equal to the laser feed depth when the light beam shrinks from the focal plane to its rotation axis. Therefore, the smaller the incident spot is, the more conducive to the increase of the depth-diameter ratio. However, the reduction of the incident spot will lead to the increase of the energy density, which challenges the tolerance of the optical system, on the other hand, the reduction of the incident spot will lead to the increase of the final focusing spot and the decrease of the energy density, resulting in the weakening of the processing capacity. Practical new type content

[0011] The utility model discloses to the technical present situation, provide a kind of laser rotary cutting processing system of promoting depth-diameter ratio, not only effectively promote depth-diameter ratio, also guarantee processing quality.

[0012] To achieve the above object, the utility model adopts the following technical scheme:

[0013] A kind of laser rotary cutting processing system of promoting depth-diameter ratio, including laser, expansion system, rotary cutting system and focusing system;

[0014] The expansion system is arranged before the laser, and the expansion system is used to enlarge the outgoing light of the laser;

[0015] The rotary cutting system is arranged before the expansion system, and the rotary cutting system is used to deflect the outgoing light of the expansion system relative to the optical axis of its incident light, while making the outgoing light of the expansion system rotate around the optical axis of its incident light;

[0016] The focusing system is arranged before the rotary cutting system, and the focusing system is used to focus the outgoing light of the rotary cutting system to the surface of workpiece to be processed;

[0017] The light transmission rotating system is provided between the expansion system and the rotary cutting system, and the light transmission rotating system includes light transmission mirror and rotating mechanism, the light transmission mirror is arranged in the rotating mechanism, the rotating mechanism is used to drive the light transmission mirror to rotate, and the rotation axis of the light transmission mirror coincides with the optical axis of the outgoing light of the expansion system;

[0018] The light transmission mirror is provided with shading structure, the shading structure is adhered and fixed on the light transmission mirror, and the shading structure is used to shield half of the incident light of the light transmission mirror in the direction perpendicular to its optical axis, and the rotation speed of the light transmission mirror is the same as the rotation speed of the outgoing light of the rotary cutting system, at the same time, when the rotary cutting system and the light transmission rotating system are in initial state, for the outgoing light of the rotary cutting system, half close to its rotation axis is reserved.

[0019] Further, the light-transmitting mirror is a Dove prism, the Dove prism has a first inclined surface and a second inclined surface, the exit light of the beam expanding system enters the Dove prism through the first inclined surface and exits the Dove prism through the second inclined surface, and the light shielding structure is arranged on the first inclined surface or the second inclined surface of the Dove prism.

[0020] Further, the light-transmitting mirror is a plane mirror, the plane mirror has a first plane and a second plane, the exit light of the beam expanding system enters the plane mirror through the first plane and exits the plane mirror through the second plane, and the light shielding structure is arranged on the first plane or the second plane of the plane mirror.

[0021] Further, the light shielding structure is a diaphragm.

[0022] Further, the rotary cutting system is a rotary prism rotary cutting system or a five-axis galvanometer rotary cutting system.

[0023] Further, the rotary cutting system comprises a galvanometer and a 4f system arranged in front of the galvanometer, the 4f system is used for performing translational transformation on the exit light of the galvanometer to a focusing system, wherein the 4f system comprises a first lens and a second lens, and the distance between the first lens and the second lens is adjustable.

[0024] Further, the laser is a superfast laser or a non-superfast laser.

[0025] Further, the wavelength of the exit light of the laser is in an ultraviolet light band, a visible light band or an infrared light band.

[0026] The laser rotary cutting machining system has the following beneficial effects:

[0027] The laser rotary cutting machining system has the following beneficial effects: BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 FIG. 1 is a schematic view of a light path structure of a laser rotary cutting machining system capable of improving a depth-diameter ratio according to the present application;

[0029] Figure 2 FIG. 4 is a comparison diagram of light shielding effects before and after the light-transmitting rotary system rotates 180° in the laser rotary cutting machining system capable of improving the depth-diameter ratio according to the present application (the section line part is a light shielding part);

[0030] Figure 3 For the laser rotary cutting machining system of the utility model, the focused light beam after the focusing system is compared with the focused light beam after the focusing system in the existing laser rotary cutting machining system (the section line part is a light shielding part).

[0031] Figure 4 For the light path schematic diagram of the rotary cutting system combined with the galvanometer and the 4f optical system.

[0032] Labeling instructions: 1, laser, 2, beam expander system, 3, light transmission rotary system, 4, light transmission mirror, 5, light shielding structure, 6, galvanometer, 7, first lens, 8, second lens, 9, reflecting mirror, 10, focusing system. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical scheme and advantages of the utility model more clear and obvious, the utility model is further described in detail below in combination with the drawings and implementation examples. It should be understood that the specific examples described here are only used to explain the utility model and not to limit the utility model.

[0034] Please refer to Figures 1-2 The laser rotary cutting machining system can improve the depth-diameter ratio, and the laser rotary cutting machining system comprises a laser 1, a beam expander system 2, a rotary cutting system and a focusing system 10.

[0035] The beam expander system 2 is arranged before the laser 1, and the beam expander system 2 is used for amplifying the outgoing light of the laser 1. Specifically, the laser 1 includes but is not limited to an ultrafast laser or a non-ultrafast laser, and the wavelength of the outgoing light of the laser 1 includes but is not limited to an ultraviolet light band or a visible light band or an infrared light band.

[0036] The rotary cutting system is arranged before the beam expander system 2, and the rotary cutting system is used for deflecting the outgoing light of the beam expander system 2 relative to the optical axis of the incident light thereof and simultaneously rotating the outgoing light of the beam expander system 2 around the optical axis of the incident light thereof. Specifically, the rotary cutting system includes but is not limited to a rotary prism type rotary cutting system or a five-axis galvanometer type rotary cutting system.

[0037] In the embodiment, the rotary cutting system comprises a galvanometer 6 and a 4f system arranged before the galvanometer 6, the galvanometer is used for deflecting the outgoing light of the beam expander system 2 relative to the optical axis of the incident light thereof and simultaneously rotating the outgoing light of the beam expander system 2 around the optical axis of the incident light thereof, and the 4f system is used for translating the outgoing light of the galvanometer 6 to the focusing system 10, wherein the 4f system comprises a first lens 7 and a second lens 8, and the distance between the first lens 7 and the second lens 8 is adjustable, that is, the rotary cutting system of the embodiment selects the rotary cutting system combined with the galvanometer 6 and the 4f optical system.

[0038] It should be noted that the rotary cutting system of the embodiment further comprises a plurality of reflecting mirrors 9, and the reflecting mirrors 9 are used for the connection of light beam propagation.

[0039] The focusing system 10 is arranged in front of the rotary cutting system, and is used for focusing the outgoing light of the rotary cutting system to the surface of the workpiece to be processed.

[0040] The light transmission rotating system 3 is arranged between the beam expanding system 2 and the rotary cutting system, and comprises a light transmission mirror 4 and a rotating mechanism (not shown in the figure). The light transmission mirror 4 is arranged in the rotating mechanism, and the rotating mechanism is used for driving the light transmission mirror 4 to rotate. The rotation axis of the light transmission mirror 4 coincides with the optical axis of the outgoing light of the beam expanding system 2. Specifically, the rotating mechanism is a hollow motor.

[0041] The light transmission mirror 4 is provided with a light shielding structure 5, and the light shielding structure 5 is adhered and fixed on the light transmission mirror 4. The light shielding structure 5 is used for shielding half of the incident light of the light transmission mirror 4 in the direction perpendicular to the optical axis of the light transmission mirror 4. The rotating speed of the light transmission mirror 4 is the same as the rotating speed of the outgoing light of the rotary cutting system. At the same time, when the rotary cutting system and the light transmission rotating system 3 are in the initial state, for the outgoing light of the rotary cutting system, half close to the rotation axis is reserved. Specifically, the light shielding structure 4 is a diaphragm.

[0042] As one of the embodiments, the light transmission mirror 4 is a Dove prism. The Dove prism has a first inclined surface and a second inclined surface. The outgoing light of the beam expanding system 2 enters the Dove prism through the first inclined surface and exits the Dove prism through the second inclined surface. The light shielding structure 4 is arranged on the first inclined surface or the second inclined surface of the Dove prism.

[0043] As another embodiment, the light transmission mirror 4 is a plane mirror. The plane mirror has a first plane and a second plane. The outgoing light of the beam expanding system 2 enters the plane mirror through the first plane and exits the plane mirror through the second plane. The light shielding structure 4 is arranged on the first plane or the second plane of the plane mirror.

[0044] The laser rotary cutting machining system based on the light shielding effect of the light shielding structure 4 makes half close to the rotation axis of the outgoing light of the rotary cutting system reserved, and then makes the outgoing light of the rotary cutting system focused by the focusing system 10. Before passing through the rotation axis, the half part on the relative outer side has no energy distribution. After passing through the rotation axis, the half part on the relative inner side has no energy distribution.

[0045] The principle of improving the depth-diameter ratio will be described below.

[0046] For the laser rotary cutting machining system, the state of the light beam after being focused by the focusing system 10 is as shown in Figure 3Wherein, the left side is the focusing state of the existing rotary cutting system, and the right side is the focusing state after the energy of half of the light beams (the section line part) is shielded. For the existing rotary cutting system, when the machining aperture is Φ, the height from the focal plane to the position where the light blocking phenomenon occurs is L, and the machining depth-diameter ratio that can be achieved is L / Φ; for the utility model, after half of the energy of the light beams is shielded and the deflection requirement of the light beams is met, the position where the light blocking phenomenon occurs is moved upward, so that the height from the focal plane to the position is L', and L' is greater than L, thus the utility model can effectively increase the depth-diameter ratio of the rotary cutting machining.

[0047] In general, according to the above design, on the one hand, the utility model can increase the feeding depth of the laser rotary cutting machining, and effectively improve the depth-diameter ratio, and on the other hand, the utility model does not affect the energy density of the light spot formed on the surface of the workpiece to be machined, and ensures the machining quality.

[0048] The utility model is not only limited to the above specific implementation, and the person skilled in the art can adopt other various specific implementation to implement the utility model according to the content disclosed by the utility model, thus, any design that adopts the design structure and idea of the utility model and makes some simple changes or alterations falls within the protection scope of the utility model.

Claims

1. A laser rotary cutting system capable of improving the aspect ratio, characterized in that: Includes laser, beam expander, rotary cutter, and focusing system; The beam expanding system is positioned in front of the laser and is used to amplify the emitted light from the laser. The spin-cutting system is positioned before the beam expander system. The spin-cutting system is used to deflect the outgoing light of the beam expander system relative to the optical axis of its incident light, and at the same time, to make the outgoing light of the beam expander system rotate around the optical axis of its incident light. The focusing system is located before the rotary cutting system and is used to focus the light emitted from the rotary cutting system onto the surface of the workpiece to be processed. A light-transmitting rotation system is provided between the beam expanding system and the rotary cutting system. The light-transmitting rotation system includes a light-transmitting mirror and a rotation mechanism. The light-transmitting mirror is disposed in the rotation mechanism, which is used to drive the light-transmitting mirror to rotate. The rotation axis of the light-transmitting mirror coincides with the optical axis of the light emitted from the beam expanding system. The light-transmitting mirror is provided with a light-shielding structure, which is adhered and fixed to the light-transmitting mirror. The light-shielding structure is used to block half of the incident light of the light-transmitting mirror in a direction perpendicular to its optical axis. The rotation speed of the light-transmitting mirror is the same as the rotation speed of the output light of the rotary cutting system. At the same time, when the rotary cutting system and the light-transmitting rotation system are in the initial state, half of the output light of the rotary cutting system is retained near its rotation axis.

2. The laser rotary cutting system for improving aspect ratio according to claim 1, characterized in that: The light-transmitting lens is a Dowell prism, which has a first inclined surface and a second inclined surface. The light emitted from the beam expanding system enters the Dowell prism through the first inclined surface and exits the Dowell prism through the second inclined surface. The light-shielding structure is arranged on the first or second inclined surface of the Dowell prism.

3. The laser rotary cutting system for improving aspect ratio according to claim 1, characterized in that: The light-transmitting mirror is a plane mirror, which has a first plane and a second plane. The light emitted from the beam expanding system enters the plane mirror through the first plane and exits the plane mirror through the second plane. The light-shielding structure is arranged on the first plane or the second plane of the plane mirror.

4. A laser rotary cutting system for improving aspect ratio according to any one of claims 1 to 3, characterized in that: The light-blocking structure is an aperture.

5. The laser rotary cutting system for improving aspect ratio according to claim 1, characterized in that: The rotary cutting system is either a rotating prism rotary cutting system or a five-axis galvanometer rotary cutting system.

6. The laser rotary cutting system for improving aspect ratio according to claim 1, characterized in that: The rotary cutting system includes a galvanometer and a 4f system disposed in front of the galvanometer. The 4f system is used to translate and transform the outgoing light from the galvanometer to the focusing system. The 4f system includes a first lens and a second lens, and the distance between the first lens and the second lens is adjustable.

7. The laser rotary cutting system for improving aspect ratio according to claim 1, characterized in that: The laser is either an ultrafast laser or a non-ultrafast laser.

8. A laser rotary cutting system for improving aspect ratio according to claim 1 or 7, characterized in that: The wavelength of the emitted light from the laser is in the ultraviolet, visible, or infrared band.

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