阅读说明：本技术 一种多光束耦合光斑的激光冲击强化装置及方法 (Laser shock peening device and method for multi-beam coupling light spots ) 是由 郭伟 张永鑫 李博 郭超 车志刚 孙汝剑 彭鹏 李钢 李卫东 于 2020-04-30 设计创作，主要内容包括：本发明公开了一种多光束耦合光斑的激光冲击强化装置及方法,自上而下依次包括：激光阵列组件、光束组合组件和聚焦组件；激光阵列组件包括主壳体和N个激光头,N≥3；激光头的布置方式为A方式：N-1个激光头呈环形均匀安装于主壳体的顶部,一个激光头安装在环形的圆心位置；B方式：N个激光头呈环形均匀安装于主壳体的顶部；光束组合组件在主壳体内部；聚焦组件位于光束组合组件下方,与环形的圆心处于同一轴心线上；该装置获得的耦合光斑可有效解决单一激光束能量不足问题,利用耦合光斑进行一次性覆盖式的大面积激光冲击强化,有效消除常规逐点冲击方式存在的产生应力先后顺序问题,形成更加均匀的残余应力场,提高零件的使用寿命。(The invention discloses a laser shock strengthening device and method for multi-beam coupling light spots, which sequentially comprise the following steps from top to bottom: the laser array assembly, the beam combination assembly and the focusing assembly; the laser array component comprises a main shell and N laser heads, wherein N is more than or equal to 3; the arrangement mode of the laser head is A mode: n-1 laser heads are uniformly arranged on the top of the main shell in an annular shape, and one laser head is arranged at the position of the center of the annular circle; mode B: the N laser heads are uniformly arranged on the top of the main shell in an annular shape; the light beam combination component is arranged inside the main shell; the focusing assembly is positioned below the light beam combination assembly and is positioned on the same axis line with the circular center of the circle; the coupling light spot obtained by the device can effectively solve the problem of insufficient energy of a single laser beam, the coupling light spot is utilized to carry out one-time covering type large-area laser shock strengthening, the problem of stress generation sequence existing in a conventional point-by-point shock mode is effectively solved, a more uniform residual stress field is formed, and the service life of parts is prolonged.)

1. The laser shock peening device of the multi-beam coupling light spot is characterized by sequentially comprising the following components from top to bottom: the laser array assembly, the beam combination assembly and the focusing assembly;

the laser array assembly includes: a main housing (1) and a plurality of laser heads (2); the number of the laser heads is N, and N is more than or equal to 3;

the laser head is arranged in an A mode or a B mode;

mode A: n-1 laser heads (2) are uniformly arranged on the top of the main shell (1) in an annular shape, and one laser head (2) is arranged at the position of the circular center; mode B: the N laser heads (2) are uniformly arranged on the top of the main shell (1) in an annular shape;

the light beam combination assembly is arranged inside the main shell (1); the focusing assembly is positioned below the light beam combination assembly and is positioned on the same axis line with the circular center of the circle;

laser beams emitted by the laser heads (2) which are uniformly arranged on the top of the main shell (1) in an annular shape are reflected by the beam combination component and then are output by the focusing component; the laser beam emitted by the laser head (2) and arranged at the position of the circular center is directly output by the focusing assembly.

2. The laser shock peening apparatus of claim 1, wherein the laser head is arranged in a mode a, the beam combining block includes: a mirror frame (3), N-1 reflector units (4) and N-1 driving mechanisms (5); the mirror bracket (3) and the driving mechanism (5) are fixedly arranged on the main shell (1);

the mirror unit (4) comprises a first mirror (41) and a second mirror (42), the first mirrors (41) are respectively mounted on the corresponding driving mechanisms (5); the second reflecting mirrors (42) correspond to the first reflecting mirrors (41) one by one, and the second reflecting mirrors (42) are arranged on the mirror frame (3);

the N-1 first reflectors (41) correspond to the N-1 laser heads (2) one by one respectively; the laser beams emitted by the N-1 laser heads (2) are incident on the corresponding first reflecting mirrors (41) and are reflected to the corresponding second reflecting mirrors (42).

3. The laser shock peening apparatus of claim 1, wherein the laser head is arranged in a B mode, and the beam combining unit includes: a mirror holder (3), N mirror units (4), and N drive mechanisms (5); the mirror bracket (3) and the driving mechanism (5) are fixedly arranged on the main shell (1);

the mirror unit (4) comprises a first mirror (41) and a second mirror (42), the first mirrors (41) are respectively mounted on the corresponding driving mechanisms (5); the second reflecting mirrors (42) correspond to the first reflecting mirrors (41) one by one, and the second reflecting mirrors (42) are arranged on the mirror frame (3);

the N first reflecting mirrors (41) correspond to the N laser heads (2) one by one respectively; the laser beams emitted by the N laser heads (2) are incident on the corresponding first reflecting mirrors (41) and are reflected to the corresponding second reflecting mirrors (42).

4. The laser shock peening apparatus for multi-beam coupled spots according to claim 2 or 3, wherein the driving mechanism (5) includes a driving motor (51) and an output shaft (52), and the driving motor (51) drives the first mirror (41) to rotate through the output shaft (52).

5. The laser shock peening apparatus for multi-beam coupled spots according to claim 4, wherein the first mirror (41) is mounted on the output shaft (52) at an angle of 45 ° to the horizontal plane.

6. The laser shock peening apparatus of claim 5, wherein the deflection angle of the first mirror (41) is in the range of 0 to 5 °, and the first mirror (41) is adjusted in the range of 45 ° to 50 ° from the vertical plane.

7. The laser shock peening apparatus for multi-beam coupled spots according to claim 2 or 3, wherein the second mirror (42) is mounted on the frame (3) at an angle of 45 ° to the horizontal.

8. The laser shock peening apparatus for multi-beam coupled spots according to claim 7, wherein the frame (3) is a regular polygon having the same number of sides as the second mirrors (42).

9. The laser shock peening apparatus for multi-beam coupled spots according to claim 1, wherein the focusing assembly is a focusing lens (6), and the focusing lens (6) is installed right below the inside of the main housing (1).

10. A laser shock peening method of multi-beam coupled light spots, wherein the laser shock peening is realized by adopting the peening device of any one of claims 1-9, and the method comprises the following steps:

s1, determining the shape and size of the coupling light spot according to the structure of the part to be shock-strengthened;

s2, determining to start the laser head at the corresponding position according to the shape of the coupling light spot;

s3, calculating the distance L from the circle center of each light spot to the focus according to the size of the coupled light spot;

s4, calculating the deflection angle alpha of the light beam combination component corresponding to each light spot according to the distance L between the center of each light spot and the focus, wherein f & tan2 alpha;

s5, adjusting according to the deflection angle alpha of the light beam combination component corresponding to each light spot to obtain coupling light spots with corresponding shape characteristics;

s6, if the lapping rate of the coupling facula is changed, the distance L from the circle center of each facula to the focus can be recalculated, and the steps S3, S4 and S5 are repeated to obtain the corresponding coupling facula.

Technical Field

The invention relates to the technical field of laser shock peening, in particular to a laser shock peening device and method for multiple beam coupling light spots.

Background

The laser shock strengthening technology utilizes high-power-density short-pulse laser to penetrate through a constraint layer and act on a material surface coating to generate a large amount of dense high-temperature and high-pressure plasmas, the plasmas continue to absorb laser energy to explode, high-strength shock waves are formed to act on a metal surface and propagate inwards, plastic deformation and dislocation structures are generated in a certain area, and high residual compressive stress is obtained on the material surface after external force is eliminated, so that the average stress level of parts is reduced when the parts are subjected to alternating load, and the fatigue performance is enhanced.

At present, most of common laser strengthening equipment is single-point type, namely after the first point is impacted, a laser spot moves to a second point to be impacted under the motion of a mechanical arm, and laser shock strengthening is sequentially carried out. According to the working mode of point-by-point impact strengthening, the energy at the laser spot is small (less than 10J), a large residual compressive stress value is difficult to generate, and the impact efficiency is low; the impact path is restricted by the motion direction of the mechanical arm, and only a laser impact strengthening area with dotting and line forming and line combining and surface forming can be completed, so that the aims of once impact and once strengthening in an area cannot be realized. Meanwhile, the working mode of point-by-point impact strengthening causes the problem of the front and back order of impact between different point positions, namely, the stress field of the impacted point position influences the next point position to be impacted, and the problem cannot be fundamentally solved in the existing laser strengthening equipment. In addition, for some complex structures, such as perforated structures, circular or square impact shapes are required to cover the area around the perforated structure, and triangular, cross-shaped, etc. impact shapes may be required under special conditions.

Therefore, how to solve the problems of insufficient energy of a single light spot, insufficient spot size and the like and adapt to the rapid laser shock peening of parts with different shapes is a problem to be solved urgently by practitioners of the same profession.

Disclosure of Invention

The present invention is directed to a multi-beam coupled spot laser shock peening apparatus and method that solves at least some of the above problems.

In order to solve the above technical problem, in one aspect, an embodiment of the present invention provides a laser shock peening apparatus for multiple beam coupled spots, which sequentially includes, from top to bottom: the laser array assembly, the beam combination assembly and the focusing assembly;

the laser array assembly includes: a main housing and a plurality of laser heads; the number of the laser heads is N, and N is more than or equal to 3;

the laser head is arranged in an A mode or a B mode;

mode A: n-1 laser heads are uniformly arranged on the top of the main shell in an annular shape, and one laser head is arranged at the position of the circular center; mode B: the N laser heads are uniformly arranged on the top of the main shell in an annular shape;

the light beam combination assembly is arranged inside the main shell; the focusing assembly is positioned below the light beam combination assembly and is positioned on the same axis line with the circular center of the circle;

laser beams emitted by the laser heads which are uniformly arranged on the top of the main shell in an annular shape are reflected by the beam combination assembly and then are output by the focusing assembly; and the laser beam emitted by the laser head arranged at the position of the circular center is directly output by the focusing assembly.

In one embodiment, the beam combining assembly comprises: when the arrangement of the laser head is in the A mode, the light beam combination assembly comprises: the device comprises a mirror frame, N-1 reflector units and N-1 driving mechanisms; the mirror bracket and the driving mechanism are fixedly arranged on the main shell;

the reflector unit comprises a first reflector and a second reflector, and the first reflectors are respectively arranged on the corresponding driving mechanisms; the second reflectors correspond to the first reflectors one by one, and are mounted on the mirror frame;

the N-1 first reflectors correspond to the N-1 laser heads one by one respectively; and laser beams emitted by the N-1 laser heads are incident on the corresponding first reflecting mirrors and are reflected to the corresponding second reflecting mirrors.

In one embodiment, when the laser head is arranged in the B mode, the beam combining assembly comprises: the mirror bracket, N reflecting mirror units and N driving mechanisms; the mirror bracket and the driving mechanism are fixedly arranged on the main shell;

the reflector unit comprises a first reflector and a second reflector, and the first reflectors are respectively arranged on the corresponding driving mechanisms; the second reflectors correspond to the first reflectors one by one, and are mounted on the mirror frame;

the N first reflectors correspond to the N laser heads one by one respectively; the laser beams emitted by the N laser heads are incident on the corresponding first reflecting mirrors and are reflected to the corresponding second reflecting mirrors.

In one embodiment, the driving mechanism includes a driving motor and an output shaft, and the driving motor drives the first reflecting mirror to rotate through the output shaft.

In one embodiment, the first reflector is mounted on the output shaft at an angle of 45 ° to the horizontal.

In one embodiment, the deflection angle of the first reflector is in the range of 0-5 degrees, and the first reflector is adjusted in the angle range of 45-50 degrees with the vertical plane.

In one embodiment, the second mirror is mounted on the frame at a 45 ° angle to the horizontal.

In one embodiment, the frame is a regular polygon having the same number of sides as the number of second mirrors.

In one embodiment, the focusing assembly is a focusing lens mounted directly below the interior of the main housing.

In another aspect, an embodiment of the present invention provides a laser shock peening method for multiple beam coupled spots, including:

s1, determining the shape and size of the coupling light spot according to the structure of the part to be shock-strengthened;

s2, determining to start the laser head at the corresponding position according to the shape of the coupling light spot;

s3, calculating the distance L from the circle center of each light spot to the focus according to the size of the coupled light spot;

s4, calculating the deflection angle alpha of the light beam combination component corresponding to each light spot according to the distance L between the center of each light spot and the focus, wherein f & tan2 alpha;

s5, adjusting according to the deflection angle alpha of the light beam combination component corresponding to each light spot to obtain coupling light spots with corresponding shape characteristics;

s6, if the lapping rate of the coupling facula is changed, the distance L from the circle center of each facula to the focus can be recalculated, and the steps S3, S4 and S5 are repeated to obtain the corresponding coupling facula.

The laser shock strengthening device and method for the multi-beam coupling light spots have the advantages that:

(1) the device has a simple and compact structure, and special impact patterns such as squares, circles, triangles and the like can be obtained by respectively setting the laser heads in the mode A or the mode B, so that the problem of limitation of single shape of the traditional laser strengthening faculae is solved.

(2) The device can effectively meet the requirements of different light spot modes in laser shock peening production; the lapping rate of the coupling light spots is changed by adjusting the deflection angle of a first reflector in the light beam combination assembly; when a plurality of laser beams are focused on one point, the problem of insufficient energy of a single laser beam can be effectively solved, the accurate control of each laser beam forming a coupling light spot can be realized, and the processing precision is improved;

(3) aiming at special structures such as round holes and the like, the coupling light spots are utilized to carry out one-time covering type large-area laser shock strengthening, the problem of stress generation sequence existing in a conventional point-by-point shock mode is solved, a more uniform residual stress field is formed, and the service life of parts is prolonged; and multiple beams of laser form coupling light spots, so that the production efficiency is obviously improved, and the cost investment is effectively saved.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

The technical solution of the present invention is further described in detail by the accompanying drawings and embodiments.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:

fig. 1 is a schematic structural diagram of a laser shock peening apparatus for multiple beam coupled spots according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a laser array apparatus for coupling multiple light beams to a light spot according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a triangular light spot output by a coupled light spot device according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a rectangular light spot output by a coupled light spot device according to an embodiment of the present invention;

fig. 5 is a schematic diagram of an output light spot of a light beam circular coupling light spot device according to an embodiment of the present invention;

fig. 6 is a schematic diagram of light spots with different overlapping ratios output by the light beam circular coupling light spot device according to the embodiment of the present invention;

fig. 7 is a flowchart of a laser shock peening method for 7-beam circular coupling spots according to an embodiment of the present invention;

FIG. 8 is a schematic view of an angular deflection of a first mirror according to an embodiment of the present invention;

fig. 9 is a schematic diagram of a specific structure of a triangular light spot according to an embodiment of the present invention;

fig. 10 is a schematic diagram of a specific structure of a rectangular light spot according to an embodiment of the present invention;

fig. 11 is a schematic diagram of a specific structure of a circular light spot provided in an embodiment of the present invention;

the laser comprises a main shell 1, a laser head 2, a laser head 3, a mirror frame 4, a reflecting mirror unit 5, a driving mechanism 6, a focusing lens 41, a first reflecting mirror 42, a second reflecting mirror 51, a driving motor 52 and an output shaft 52.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.