Thin-wall curved surface part micro group hole and special-shaped hole cutting process machining method based on laser field lens light beam scanning

Abstract

The invention relates to the technical field of non-traditional machining, in particular to a thin-wall curved surface part micro group hole and special-shaped hole cutting process machining method based on laser field lens light beam scanning, which comprises the following steps: S1, dividing N machining areas on the curved surface of a thin-wall curved surface part according to a single laser scanning machining area; s2, automatic laser focus searching is conducted on each machining area, and focus position data scanned by a laser beam during automatic focus searching are recorded into a machining program; s3, micro group holes and special-shaped holes in the thin-wall curved-surface part are scanned and machined through a flat field lens by adopting light beams of a movable light type laser field lens; and S4, cleaning and checking are conducted, and finished parts are obtained. Ultrafast laser is adopted as an energy source, a high-speed galvanometer and a flat field lens are combined, a laser focus regional automatic focus searching process and a dynamic light type light beam scanning processing process are innovatively developed, and the laser field lens light beam scanning process is adopted to realize scanning cutting processing of thin-wall micro group holes, special-shaped holes and thin-wall outlines.

Description

Technical Field

[0001] The invention relates to the technical field of special processing, and in particular to a cutting process method for tiny group holes and special-shaped holes of thin-walled curved surface parts based on laser field mirror beam scanning. Background Art

[0002] At present, for thin-walled (thickness δ1 < 0.5mm) micro-group hole processing, the traditional axis movement single-hole processing method is mostly used, mainly using mechanical drilling, EDM drilling, laser drilling, electrolytic drilling and other process methods; for holes with high surface quality requirements, EDM-electrolysis, laser-electrolysis, ultrasonic-electrodischarge and other composite processing methods are often used, or post-processing processes such as burrs, flash, and remelting layer removal are added to improve the hole quality; for special-shaped holes (thickness δ2 < 0.5mm), axis movement is often used for cutting path programming laser cutting or EDM forming electrode replication process methods.

[0003] For the traditional single-hole processing method with axis movement, mechanical drilling often has flash, large burrs, poor surface integrity, metamorphic hardened layer, microcracks and heat-affected zone, and is prone to drill jamming and drill breakage; single processing such as EDM and laser often has remelting layer, microcracks and heat-affected zone; electrolytic processing has problems such as low efficiency, electrolyte environmental pollution, and long pre-process preparation time. For the new composite small hole processing methods that have emerged one after another (electrodischarge-electrolysis, laser-electrolysis, ultrasonic-electrodischarge, etc.), there are problems such as unstable process, large taper of deep small hole processing, residual remelting layer, poor consistency of hole mouth and hole diameter, and subsequent post-processing process of hole surface (removal of burrs, flash, remelting layer, etc.) is required to improve the hole quality, the process is long and the efficiency is low. For special-shaped holes, the axis movement laser cutting process requires cutting path programming, and the EDM forming electrode replication process requires the manufacture of cathode electrode tools, which has a long processing cycle and low efficiency. Summary of the invention

[0004] In view of the problem that thin-walled tiny group holes and special-shaped holes are difficult to process in the prior art, the present invention provides a cutting process method for tiny group holes and special-shaped holes of thin-walled curved surface parts based on laser field mirror beam scanning.

[0005] The present invention is achieved through the following technical solutions: A method for cutting micro-group holes and special-shaped holes of thin-walled curved surface parts based on laser field mirror beam scanning, comprising the following steps: S1, dividing N processing areas on the surface of the thin-walled curved surface part according to the single laser scanning processing area; S2, automatically searching the laser focus for each processing area, and recording the focus position data of the laser beam scanning during the automatic searching into the processing program; S3, using a dynamic laser field mirror beam to scan and process tiny group holes and special-shaped holes on thin-walled curved surface parts through a flat field lens, and to scan and cut thin-wall contours; wherein the thickness of the thin-walled curved surface parts is δ<0.5mm; S4, clean and inspect the processed parts to obtain finished parts.

[0006] Preferably, in S1, the processing area is an automatic focusing area of ​​the laser focus, and the area of ​​the automatic focusing area is not greater than 60% of the surface area of ​​the field lens.

[0007] Preferably, in S2, the thin-walled curved surface part is installed on the rotating C-axis of the equipment through a quick-change fixture. During automatic focusing, an automatic focusing program is compiled to automatically focus the laser focus area to be measured through the quick-change fixture, and the laser focus automatic focusing area to be measured is automatically focused by the program through the laser rangefinder.

[0008] Preferably, during automatic focusing, focusing is performed multiple times in each processing area.

[0009] Preferably, in S3, during processing, the circular air film hole group processing program is first called to process the circular air film tiny hole groups on the thin-walled curved surface parts, then the special-shaped air film hole processing program is called to process all the special-shaped air film holes on the parts, and finally the cutting processing program is called to cut and process the contour of the thin-walled curved surface parts.

[0010] Preferably, in S3, during processing, the pulse width of the laser is 290fs~15ps, the pulse frequency is 100~200kHZ, the laser power percentage is 60~95%, and the defocus amount is -1~1mm.

[0011] Preferably, in S3, a layered processing method is adopted during processing, and the interlayer spacing between two adjacent layers is 0.005-0.02 mm.

[0012] Preferably, in S3, during processing, the scanning time of a single layer of the galvanometer is 3000-60000 ms, the scanning speed is 2000-20000 mm / s, and the line spacing is 0.005-0.02 mm.

[0013] Preferably, in S3, during processing, oxygen or argon is used as the auxiliary gas, and the gas pressure is 0.6-1.0 MPa.

[0014] A product obtained by a cutting process method for tiny group holes and special-shaped holes of thin-walled curved surface parts based on laser field mirror beam scanning.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention discloses a method for cutting micro-group holes and special-shaped holes of thin-walled curved surface parts based on laser field mirror beam scanning. The method uses ultrafast laser as the energy source, combines a high-speed galvanometer with a field mirror, and forms a flat focal plane on the processing work surface through a flat field lens. The method uses a two-dimensional (galvanometer X-axis, galvanometer Y-axis) beam scanning mode (dynamic light type) and a Z-axis parameter linkage control (third axis) feeding to form a three-axis linkage for cutting. When the Z-axis parameter linkage control feeds, the processing depth is controlled with the parameters. At the same time, a laser focus automatic focus search process method and a beam scanning process (dynamic light type) are developed to achieve efficient and high-quality cutting of thin-walled micro-group holes and special-shaped holes. Compared with the traditional axis movement single hole rotary cutting process, impact processing process, and special-shaped hole trajectory cutting or cathode motor replication process, the method proposed by the present invention has higher processing efficiency, and the surface integrity of micro-group holes and special-shaped holes is better.

[0016] This method adopts the laser focus area automatic focus search process and the beam scanning processing (dynamic light type) process, and combines the galvanometer and the field mirror to achieve high processing efficiency and good quality. The processing efficiency is 10 times that of the conventional single hole (fixed light type) processing; the galvanometer X-axis, galvanometer Y-axis and Z-axis parameters are linked to form a 3-axis linkage for cutting processing to achieve aperture taper and shape parameter control and improve processing quality accuracy; the flat focal plane focusing processing is used to ensure the consistency of the hole surface shape quality, avoid beam focus distortion, processing depth and shape deformation; ultrafast laser (femtosecond, picosecond) processing is used, and its "cold" processing characteristics are used. After laser processing, no remelting layer or heat-affected zone is generated, and high-quality processing without remelting layer, microcracks and heat-affected zone can be achieved. Furthermore, the processing is performed according to the steps of first processing conventional circular air film group holes, then processing special-shaped holes, and finally performing contour cutting, so as to prevent thin-walled curved surface parts from warping and deforming during the cutting process, thereby affecting the hole shape and position accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a flow chart of a method for cutting micro-group holes and special-shaped holes of thin-walled curved surface parts based on laser field mirror beam scanning of the present invention; Figure 2 It is a principle diagram of a cutting process method for micro-group holes and special-shaped holes of thin-walled curved surface parts based on laser field mirror beam scanning of the present invention; Figure 3 This is a schematic diagram of the method for obtaining a flat focal plane by using the mid-field mirror in the invention; Figure 4 This is a schematic diagram of the laser focus automatic focus search in different areas in the present invention; Figure 5 It is a schematic diagram of processing of micro-group holes and special-shaped holes in the present invention.

[0018] In the figure, 1. Ultrafast laser beam; 2. Two-dimensional galvanometer scanning system; 3. Flat field lens; 4. Z axis; 5. Processing work surface; 6. Processing area; 7. Flat focal plane; 8. Thin-walled curved parts; 10. Quick-change tooling; 11. Laser rangefinder; 12. Focusing area; 13. Processing horizontal plane; 14. Tiny group holes; 15. Special-shaped holes; 16. Thin-walled contour; 17. Thin-walled molded parts. DETAILED DESCRIPTION

[0019] The present invention is further described in detail below in conjunction with specific embodiments, which are intended to explain the present invention rather than to limit it.

[0020] The present invention discloses a cutting process for micro-group holes and special-shaped holes of thin-walled curved surface parts based on laser field mirror beam scanning, referring to Figure 1 , including the following steps: S1, using CAD software, divide the surface of the thin-walled curved part 8 into N processing areas 6 according to the single laser scanning processing area; the processing area 6 is the laser focus automatic focusing area 12, and the area of ​​the automatic focusing area 12 is not greater than 60% of the surface area of ​​the field mirror, so as to prevent the geometric distortion of the laser galvanometer scanning field, the focus distortion of the light beam, and the influence of trapezoidal and rhombus distortion on the part quality.

[0021] S2, automatically searching the laser focus for each processing area 6, and recording the focus position data of the laser beam scanning during the automatic searching into the processing program.

[0022] Specifically, the thin-walled curved surface part 8 is installed on the rotating C axis of the equipment through the quick-change fixture 10. When automatically focusing, the automatic focusing program is compiled to automatically focus the laser focus area 12 to be measured through the quick-change fixture 10, and the laser rangefinder 11 is used to automatically focus the laser focus area 12 to be measured. Multiple focusing is performed in each processing area 6. The processing area 6 is divided into N areas, and N automatic focusing is performed. The automatic positioning and automatic focusing of each area are performed by relying on the compiled automatic focusing program. Figure 4 Schematic diagram of focusing at different positions of a thin-walled curved surface part 8.

[0023] S3, using a dynamic laser field mirror beam to scan and process tiny group holes 14, special-shaped holes 15 on a thin-walled curved surface part 8 through a flat field lens 3, and to scan and cut a thin-walled contour 16; wherein the thickness δ of the thin-walled curved surface part 8 is less than 0.5 mm.

[0024] Specifically, during processing, the circular air film hole group processing program is first called to process the circular air film hole micro-group 14 on the thin-walled curved surface part 8, and then the special-shaped hole 15 processing program is called to process all the special-shaped holes 15 on the part, and finally the cutting processing program is called to cut and process the thin-wall contour 16 of the thin-walled curved surface part 8.

[0025] During processing, the laser pulse width is 290fs~15ps, the pulse frequency is 100~200kHZ, the laser power percentage is 60~95%, and the defocus is -1~1mm; a layered processing method is adopted, and the interlayer spacing between two adjacent layers is 0.005~0.02mm; the galvanometer single-layer scanning time is 3000~60000ms, the scanning speed is 2000~20000mm / s, and the line spacing is 0.005~0.02mm; oxygen or argon is used as auxiliary gas, and the gas pressure is 0.6~1.0MPa.

[0026] S4, cleans and inspects the parts processed in S3 to obtain finished parts.

[0027] Reference Figure 2 The present invention discloses a cutting process method for thin-walled micro-hole groups and special-shaped holes 15 based on laser field mirror beam scanning (dynamic light type). The principle is: using ultrafast laser (femtosecond, picosecond) as the energy source, a two-dimensional galvanometer scanning system (galvanometer X-axis, galvanometer Y-axis) and a Z-axis 4 are linked with the parameters to control the depth system to form a three-axis linkage processing, an ultrafast laser beam 1 is scanned through a flat field lens 3, the laser focus is concentrated on a processing work plane, and thin-walled micro-hole groups and special-shaped holes 15 are proportionally processed in a processing area 6 of the processing work plane.

[0028] At the same time, in order to avoid the focus distortion, processing depth and shape deformation of the light beam, a flat focal plane 7 (focus A' and B' at different positions are in the same plane) is obtained in combination with a flat field lens 3 at different incident angles (far field and near field) of the ultrafast laser beam 1 (see Figure 3 ), in order to ensure the consistency of the hole surface shape quality, avoid the focus distortion of the light beam, processing depth and shape deformation, a focusing lens capable of flattening the field, the flat field lens 3, is used to obtain a flat focal plane 7 (focus A' and B' at different positions are in the same plane) at different incident angles of the laser beam (far field and near field). On the processing work surface 5 (flat focal plane 7 = processing work surface 5), a laser focus automatic focus search process method is developed by dividing the focus into different areas (see Figure 4 ) and laser beam scanning processing (dynamic light) process (see Figure 5 ), achieving efficient and high-quality cutting of thin-walled micro-hole clusters and special-shaped holes 15.

[0029] The present invention discloses a method for cutting micro-group holes and special-shaped holes of thin-walled curved surface parts based on laser field mirror beam scanning, including an ultrafast laser (femtosecond, picosecond) beam scanning hole-making process, and relates to a method for cutting thin-walled micro-group holes and special-shaped holes 15. It is an innovative processing method, which can realize the effective combination of ultrafast laser (femtosecond, picosecond), high-speed galvanometer and flat field lens 3 and laser focus automatic focusing in different regions, beam scanning processing (dynamic light type) process and z-axis parameter linkage control, realize beam scanning 3-axis linkage processing, improve processing quality and efficiency, and adopt the dynamic light type processing galvanometer deflection to generate a laser scanning speed of 8000mm / s, which is 10 to 15 times more efficient than fixed light processing, and eliminates the post-processing process of the hole surface (removal of burrs, flash, remelting layer, etc.), further improving the overall processing efficiency of the workpiece. At the same time, the process selectivity of the thin-walled micro-group hole and special-shaped hole 15 processing method is increased to achieve efficient and high-quality processing.

[0030] The invention also discloses a product obtained by a cutting process method for micro-group holes and special-shaped holes of thin-walled curved surface parts based on laser field mirror beam scanning.

[0031] Take a thin-walled part of a guide blade upper cover plate for processing ( Figure 5 Take the example of the thin-walled upper cover plate of the guide blade, with a wall thickness of δ=0.3mm, 120 air film holes 14 distributed on the surface, the micro-pore air film hole 14 has a hole diameter of Φ0.65±0.1mm, and the special-shaped static pressure hole is Φ10.8±0.1mm, with an irregular polygonal shape. It is required to be free of burrs, flash, deformation and scratches; and the hole surface roughness Ra1.6 and the metallographic structure requirements are relatively high (no remelting layer, no microcracks, no heat-affected zone). The thin-walled micro-group hole 14 and special-shaped hole 15 cutting process method based on laser field mirror beam scanning proposed by the present invention are used for processing. The specific steps are as follows: S1, using CAD software, the surface parts are divided into processing areas 6 according to the single laser scanning processing area.

[0032] S2, install the part on the rotating C-axis of the equipment through the quick-change tooling 10, and when performing automatic focusing in the different divided areas, compile an automatic focusing program to adjust the laser focus automatic focusing area 12 to be measured to the processing horizontal plane 13 through the quick-change tooling 10, and perform program automatic focusing on the laser focus automatic focusing area 12 to be measured through the laser rangefinder 11.

[0033] S3, automatically recording the auto-focusing data (the focal position of the laser beam scanning) in the processing program, and performing the processing in the following order; 1) Call the circular air film group hole processing program and use the laser field mirror beam scanning process (dynamic light type) to process all the circular air film micro-group holes on the parts 14 ( Figure 5-1 as shown).

[0034] 2) Call the special-shaped hole 15 processing program and use the laser field mirror beam scanning process (dynamic light type) to process all the special-shaped holes 15 on the parts ( Figure 5-2 as shown).

[0035] 3) Call the cutting program and use the laser field mirror beam scanning process (dynamic light type) to perform thin-wall contour 16 cutting ( Figure 5-3 as shown).

[0036] The relevant parameters during processing are: 1) the pulse width of the femtosecond laser is 290fs; 2) the pulse frequency is 100kHZ; 3) the laser power percentage is determined to be 85%; 4) the defocus amount is 0mm; 5) the laser processing method is the dynamic light beam scanning method; 6) the number of processing layers is 30 layers; 7) the layer spacing is 0.01mm; 8) the galvanometer single layer scanning time is 28000ms; 9) the scanning speed is 6000mm / s; 9) the line spacing is 0.005mm; 10) the auxiliary gas is argon, and the gas pressure is 0.8MPa.

[0037] S4, the processed thin-walled molded part 17 ( Figure 5-4 As shown), use a compressed air gun to blow away metal dust and pollutants on the surface of the workpiece, and check the cutting quality of each small group of holes 14, special-shaped holes 15 and thin-walled contours 16.

[0038] The above description is only a preferred embodiment of the present invention and is not intended to impose any limitation on the technical solution of the present invention. Those skilled in the art should understand that, without departing from the spirit and principles of the present invention, the technical solution can also be subjected to several simple modifications and substitutions, and these modifications and substitutions are also within the scope of protection covered by the claims.

Claims

1. A method for cutting micro-holes and special-shaped holes of thin-walled curved parts based on laser field mirror beam scanning, characterized in that: The following steps are involved: S1, dividing N processing areas on the surface of the thin-walled curved surface part according to the single laser scanning processing area; S2, automatically searching the laser focus for each processing area, and recording the focus position data of the laser beam scanning during the automatic searching into the processing program; S3, using a dynamic laser field mirror beam to scan and process tiny group holes and special-shaped holes on thin-walled curved surface parts through a flat field lens, and to scan and cut thin-wall contours; wherein the thickness of the thin-walled curved surface parts is δ<0.5mm; S4, clean and inspect the processed parts to obtain finished parts.

2. The method for cutting micro-hole groups and special-shaped holes of thin-walled curved surface parts based on laser field mirror beam scanning according to claim 1 is characterized in that: In S1, the processing area is the laser focus automatic focus area, and the area of ​​the automatic focus area is not greater than 60% of the surface area of ​​the field lens.

3. The method for cutting micro-hole groups and special-shaped holes of thin-walled curved surface parts based on laser field mirror beam scanning according to claim 2 is characterized in that: In S2, the thin-walled curved surface parts are installed on the rotary C-axis of the equipment through a quick-change fixture. During automatic focusing, an automatic focusing program is compiled to automatically focus the laser focus area to be measured through the quick-change fixture, and the laser rangefinder is used to automatically focus the laser focus area to be measured.

4. The method for cutting micro-hole groups and special-shaped holes of thin-walled curved surface parts based on laser field mirror beam scanning according to claim 3 is characterized in that: During automatic focus search, multiple focus searches are performed in each processing area.

5. The method for cutting micro-hole groups and special-shaped holes of thin-walled curved surface parts based on laser field mirror beam scanning according to claim 1 is characterized in that: In S3, during processing, the circular air film hole processing program is first called to process the circular air film tiny hole clusters on the thin-walled curved surface parts, and then the special-shaped air film hole processing program is called to process all the special-shaped air film holes on the parts, and finally the cutting processing program is called to cut the contour of the thin-walled curved surface parts.

6. The method for cutting micro-hole groups and special-shaped holes of thin-walled curved surface parts based on laser field mirror beam scanning according to claim 5 is characterized in that: In S3, the pulse width of the laser during processing is 290fs~15ps, the pulse frequency is 100~200kHZ, the laser power percentage is 60~95%, and the defocus amount is -1~1mm.

7. The method for cutting micro-hole groups and special-shaped holes of thin-walled curved surface parts based on laser field mirror beam scanning according to claim 5 is characterized in that: In S3, a layered processing method is used during processing, and the interlayer spacing between two adjacent layers is 0.005~0.02mm.

8. The method for cutting micro-hole groups and special-shaped holes of thin-walled curved surface parts based on laser field mirror beam scanning according to claim 5, characterized in that: In S3, the single-layer scanning time of the galvanometer during processing is 3000~60000ms, the scanning speed is 2000~20000mm / s, and the line spacing is 0.005~0.02mm.

9. The method for cutting micro-hole groups and special-shaped holes of thin-walled curved surface parts based on laser field mirror beam scanning according to claim 5, characterized in that: In S3, during processing, oxygen or argon is used as the auxiliary gas, and the gas pressure is 0.6~1.0MPa.

10. A product obtained by the method for cutting micro-hole clusters and special-shaped holes of thin-walled curved surface parts based on laser field mirror beam scanning according to any one of claims 1 to 9.

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