A micro-group hole and special-shaped hole cutting process method of a thin-wall curved surface part based on a laser field mirror beam scanning

Abstract

The present application relates to the field of special processing technology, in particular to a kind of micro group hole and special-shaped hole cutting process processing method of thin-walled curved surface parts based on laser field mirror beam scanning, steps are as follows: S1, according to single laser scanning processing area, divide N processing areas on the curved surface of thin-walled curved surface parts;S2, laser focal point automatic focusing is carried out to each processing area respectively, and the focal point position data of laser beam scanning when automatic focusing is recorded into processing program;S3, dynamic light type laser field mirror beam is scanned through flat field lens to process micro group hole and special-shaped hole on thin-walled curved surface parts;S4, clean and check, obtain finished parts.The present application uses ultrafast laser as energy source, combines high-speed galvanometer and flat field lens, innovatively develops laser focal point subarea automatic focusing process and dynamic light type beam scanning processing process, and realizes scanning cutting processing to thin-walled micro group hole, special-shaped hole and thin-walled contour by using laser field mirror beam scanning process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of special processing, in particular to a micro-group hole and special-shaped hole cutting process of a thin-walled curved surface part based on laser field mirror beam scanning. BACKGROUND

[0002] At present, the traditional shaft moving one-by-one single hole processing method is mainly used for thin-walled (thickness δ1<0.5mm) micro-group hole processing, and the mechanical drilling, electric spark punching, laser punching and electrolytic punching process methods are mainly used; for the holes with high surface quality requirements, the electric spark-electrolytic, laser-electrolytic and ultrasonic-electric spark composite processing methods or the hole surface post-processing technology (burr, flash, re-melt layer removal, etc.) are used to improve the hole quality; for the special-shaped holes (thickness δ2<0.5mm), the shaft moving method is used for laser cutting or electric spark forming electrode copying process method.

[0003] For the traditional shaft moving one-by-one single hole processing method, the mechanical drilling has the problems of large burr, poor surface integrity, existence of modified hardened layer, micro-cracks and heat affected zone, and easy occurrence of drill jamming and drill breaking; the electric spark and laser single processing methods have the problems of re-melt layer, micro-cracks and heat affected zone; the electrolytic processing has the problems of low efficiency, electrolyte environmental pollution, long pre-process preparation time and the like. For the newly emerging new type of composite small hole processing methods (electric spark-electrolytic, laser-electrolytic, ultrasonic-electric spark, etc.), there are problems of unstable process, large taper of deep small hole processing, re-melt layer residue, poor consistency of hole diameter and the like, and the hole quality needs to be improved by using the hole surface post-processing technology (burr, flash, re-melt layer removal, etc.) in the subsequent process, which has long process and low efficiency. For the special-shaped hole laser cutting process using the shaft moving method, the cutting path programming is needed, and the electric spark forming electrode copying process needs to manufacture the cathode electrode tool, which has long processing cycle and low efficiency. SUMMARY

[0004] In view of the problem that the thin-walled micro-group hole and special-shaped hole are not easy to process in the prior art, the present application provides a micro-group hole and special-shaped hole cutting process of a thin-walled curved surface part based on laser field mirror beam scanning.

[0005] The present application is realized by the following technical scheme:

[0006] A micro-group hole and special-shaped hole cutting process of a thin-walled curved surface part based on laser field mirror beam scanning, comprising the following steps:

[0007] S1, dividing N processing areas on the curved surface of the thin-walled curved surface part according to the single laser scanning processing area;

[0008] S2, automatically focus the laser focus point for each processing area respectively, and record the focus point position data of the laser beam scanning during the automatic focusing to the processing program;

[0009] S3, adopt the dynamic light type laser field mirror light beam to pass through the flat field lens to scan and process the micro group holes and special-shaped holes on the thin-walled curved surface part, and cut the thin-walled profile; wherein the thickness δ of the thin-walled curved surface part is less than 0.5mm;

[0010] S4, clean and inspect the processed part to obtain the finished part.

[0011] Preferably, in S1, the processing area is the automatic focusing area of the laser focus point, and the area of the automatic focusing area is not greater than 60% of the surface area of the field mirror.

[0012] Preferably, in S2, the thin-walled curved surface part is installed on the equipment rotary C shaft through quick-change tooling, and when automatic focusing, the automatic focusing program is compiled to automatically focus the laser focus point automatic focusing area to be measured through the quick-change tooling, and the laser distance meter is used to automatically focus the laser focus point automatic focusing area to be measured.

[0013] Preferably, during automatic focusing, multiple focusing is performed in each processing area.

[0014] Preferably, in S3, during processing, first, the circular air film group hole processing program is called to process the circular air film micro group holes on the thin-walled curved surface part, then the special-shaped air film hole processing program is called to process all special-shaped air film holes on the part, and finally the cutting processing program is called to cut and process the profile of the thin-walled curved surface part.

[0015] 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 defocusing amount is -1~1mm.

[0016] Preferably, in S3, during processing, a layered processing method is adopted, and the layer spacing between adjacent two layers is 0.005~0.02mm.

[0017] Preferably, in S3, during processing, 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.

[0018] Preferably, in S3, during processing, oxygen or argon is used as the auxiliary gas, and the gas pressure is 0.6~1.0MPa.

[0019] A product obtained by a thin-walled curved surface part micro group hole and special-shaped hole cutting process method based on laser field mirror light beam scanning.

[0020] Compared with the prior art, the present application has the following beneficial effects:

[0021] The present application is a kind of micro group hole and special-shaped hole cutting process of thin-walled curved surface parts based on laser field mirror beam scanning, which uses ultrafast laser as energy source, combines high-speed galvanometer with field mirror, and forms a flat focal plane on the machining work surface through a flat field lens. The 3-axis linkage cutting is formed by two-dimensional (galvanometer X-axis, galvanometer Y-axis) beam scanning mode (dynamic light type) and Z-axis parameter linkage control (third axis) feeding. When the Z-axis parameter linkage control feeding is performed, the machining depth is controlled by parameters at the same time. The laser focal point sub-area automatic focusing process and beam scanning processing (dynamic light type) process are developed to realize high-efficiency and high-quality cutting of thin-walled micro group holes and special-shaped holes. Compared with the traditional single-hole rotary cutting processing, impact processing technology and special-shaped hole trajectory cutting or cathode motor reprocessing, the method proposed in the present application has higher processing efficiency, and the surface integrity of the micro group hole and the special-shaped hole is better.

[0022] The present application adopts laser focal point sub-area automatic focusing process and beam scanning processing (dynamic light type) process, combines galvanometer with field mirror, has high processing efficiency and good quality. The processing efficiency is 10 times that of conventional single-hole (fixed light type) processing. The galvanometer X-axis, galvanometer Y-axis and Z-axis parameter linkage control are used to form 3-axis linkage cutting to realize aperture taper and shape parameter control and improve the processing quality and precision. The flat focal plane focusing processing is used to ensure the consistency of the hole type surface shape quality, avoid the distortion of the focal point of the beam, and the deformation of the machining depth and shape. The ultrafast laser (femtosecond, picosecond) processing is used to realize high-quality processing without remelt layer, micro crack and heat-affected zone by using its "cold" processing characteristics.

[0023] Further, the steps of first processing conventional circular gas film group holes, then processing special-shaped holes, and finally performing contour cutting are performed to prevent the thin-walled curved surface part from being warped and deformed during cutting, which affects the hole type shape and position degree. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a flow chart of the present application, which is a micro group hole and special-shaped hole cutting process of thin-walled curved surface parts based on laser field mirror beam scanning;

[0025] Figure 2 is a principle diagram of the present application, which is a micro group hole and special-shaped hole cutting process of thin-walled curved surface parts based on laser field mirror beam scanning;

[0026] Figure 3 is a schematic diagram of the present application, which is a schematic diagram of the field mirror obtaining a flat focal plane;

[0027] Figure 4is a schematic diagram of automatic focusing of laser focal points in the present application by region;

[0028] Figure 5 is a schematic diagram of micro-group hole and special-shaped hole processing in the present application.

[0029] In the figure, 1 is an ultrafast laser beam; 2 is a two-dimensional galvanometer scanning system; 3 is a flat-field lens; 4 is a Z-axis; 5 is a machining work surface; 6 is a machining region; 7 is a flat focusing plane; 8 is a thin-walled curved surface part; 10 is a quick-change tooling; 11 is a laser range finder; 12 is a focusing region; 13 is a machining horizontal plane; 14 is a micro-group hole; 15 is a special-shaped hole; 16 is a thin-walled profile; and 17 is a thin-walled formed part. DETAILED DESCRIPTION

[0030] The present application will be further described in detail below in combination with specific examples, which are an explanation of the present application rather than a limitation.

[0031] The present application discloses a micro-group hole and special-shaped hole cutting process machining method for a thin-walled curved surface part based on a laser field mirror light beam scanning, referring to Figure 1 , comprising the following steps:

[0032] S1, using a CAD software, N machining regions 6 are divided on the curved surface of the thin-walled curved surface part 8 according to a single laser scanning machining area; the machining region 6 is a laser focal point automatic focusing region 12, and the area of the automatic focusing region 12 is not greater than 60% of the surface area of the field mirror, so that the influences of geometric distortion of the laser galvanometer scanning field, focal point distortion of the light beam, trapezoidal and diamond distortion on the part quality can be prevented.

[0033] S2, the laser focal point automatic focusing is respectively performed on each machining region 6, and the focal point position data of the laser beam scanning during the automatic focusing is recorded into a machining program.

[0034] Specifically, the thin-walled curved surface part 8 is installed on a device rotary C-axis through the quick-change tooling 10, an automatic focusing program is compiled to automatically focus the laser focal point automatic focusing region 12 needing to be measured through the quick-change tooling 10, and the laser focal point automatic focusing region 12 needing to be measured is subjected to program automatic focusing through the laser range finder 11. Multiple focusing is performed in each machining region 6, N regions are divided in the machining region 6, N times of automatic focusing are performed, and automatic positioning and automatic focusing by region are performed by means of the compiled automatic focusing program, Figure 4 is a schematic diagram of focusing of different parts of the thin-walled curved surface part 8.

[0035] S3, a dynamic light type laser field mirror light beam is scanned through the flat-field lens 3 to machine the micro-group hole 14, the special-shaped hole 15 and scan and cut the thin-walled profile 16 on the thin-walled curved surface part 8; wherein the thickness δ of the thin-walled curved surface part 8 is less than 0.5 mm.

[0036] Specifically, during processing, firstly, the circular air film group hole processing program is called to process the small group holes 14 of the circular air film holes on the thin-walled curved surface part 8, 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 the thin-walled profile 16 of the thin-walled curved surface part 8.

[0037] During processing, the pulse width of the laser is 290fs~15ps, the pulse frequency is 100~200kHZ, the laser power percentage is 60~95%, the defocusing amount is -1~1mm; a layered processing method is adopted, the layer spacing between adjacent two 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 the auxiliary gas, and the gas pressure is 0.6~1.0MPa.

[0038] S4, cleaning and checking the part processed in S3 to obtain a finished part.

[0039] Referring to Figure 2 , the principle of the thin-walled small group hole and special-shaped hole 15 cutting process processing method based on the laser field mirror light beam scanning (dynamic light type) is: taking the ultrafast laser (femtosecond, picosecond) as an energy source, a two-dimensional galvanometer scanning system (galvanometer X axis, galvanometer Y axis) and a Z axis 4 parameter linkage control depth system form a 3-axis linkage processing, the ultrafast laser beam 1 is scanned and processed through the flat field lens 3, the laser focus is gathered on the processing working plane, and the thin-walled small group hole and special-shaped hole 15 are processed in proportion in the processing area 6 of the processing working plane.

[0040] At the same time, in order to avoid the distortion of the focal point of the light beam, the deformation of the processing depth and shape, and in combination with the flat field lens 3, a flat focus plane 7 (different position focal points A', B' are in a plane) is obtained in different incident angle directions (far field and near field) of the ultrafast laser beam 1 (see Figure 3 ), in order to ensure the consistency of the hole type surface shape quality, avoid the distortion of the focal point of the light beam, and the deformation of the processing depth and shape, a flat field focusing lens - flat field lens 3 is used to obtain a flat focus plane 7 (different position focal points A', B' are in a plane) in different incident angle directions (far field and near field) of the laser beam. Through the development of the laser focal point regional automatic focusing process method (see Figure 4 ) and the laser beam scanning processing (dynamic light type) process (see Figure 5 ), the thin-walled small group hole and special-shaped hole 15 high-efficiency and high-quality cutting processing is realized.

[0041] The application discloses a kind of based on laser field mirror beam scanning's thin-walled curved surface part's little group hole and special-shaped hole cutting process machining method, including ultrafast laser (femtosecond, picosecond) beam scanning hole processing technology, it is related to thin-walled little group hole and special-shaped hole 15 cutting method, it is a kind of innovative processing method, can realize ultrafast laser (femtosecond, picosecond), high-speed galvanometer and flat field lens 3 and laser focal point subarea automatic focusing, beam scanning processing (dynamic light type) technology and z-axis parameter linkage control Effective combination, realize beam scanning 3-axis linkage processing, improve processing quality and efficiency, using dynamic light type processing galvanometer deflection generated laser scanning speed, generally can reach 8000mm / s, compared with fixed light type processing, efficiency is improved 10~15 times, eliminates hole surface post-processing technology (burr, fin, re-melt layer removal etc.), further improve the overall processing efficiency of workpiece.Simultaneously, increase the thin-walled little group hole and special-shaped hole 15 processing method technology selectivity, realize efficient high-quality processing.

[0042] The application further discloses a product obtained by the method.

[0043] Taking the processing of a guide vane upper cover plate thin-walled part as an example, Figure 5 as shown in the drawing, the guide vane upper cover plate thin-walled part has a wall thickness δ of 0.3 mm, a surface distributed with 120 film holes 14, the micro small hole film hole 14 has a hole diameter of Φ0.65±0.1 mm, a special-shaped static pressure hole Φ10.8±0.1 mm, and an irregular polygonal shape. No burr, no fin, no deformation and no scratch are required; the hole surface roughness Ra is 1.6, and the metallographic structure requirement is high (no re-melt layer, no micro crack, and no heat affected zone). The application provides a kind of based on laser field mirror beam scanning's thin-walled little group hole 14 and special-shaped hole 15 cutting process machining method, which is used for processing the guide vane upper cover plate thin-walled part, and the specific steps are as follows:

[0044] S1, a CAD software is used to divide the processing area 6 of the curved surface part according to single laser scanning processing area.

[0045] S2, the part is installed on the equipment rotary C shaft through the quick-change tool 10, and the automatic focusing program is compiled to adjust the laser focal point automatic focusing area 12 to be measured to the processing horizontal plane 13 position when automatic focusing in different areas divided, and the laser focal point automatic focusing area 12 to be measured is automatically focused by the laser range finder 11.

[0046] S3, the automatic focusing data (laser beam scanning focal point position) is automatically recorded in the processing program, and the processing is carried out according to the following order.

[0047] 1) call the circular gas film group hole processing program, adopt the laser field mirror beam scanning process (dynamic light type) to process all circular gas film micro group holes 14 on the part (as shown in Figure 5-1

[0048] 2) call the special-shaped hole 15 processing program, adopt the laser field mirror beam scanning process (dynamic light type) to process all special-shaped holes 15 on the part (as shown in Figure 5-2

[0049] 3) call the cutting processing program, adopt the laser field mirror beam scanning process (dynamic light type) to carry out thin-walled contour 16 cutting processing (as shown in Figure 5-3

[0050] The related parameters during processing are: 1) femtosecond laser pulse width is 290fs; 2) pulse frequency is 100kHZ; 3) the determined laser power percentage is 85%; 4) the defocusing amount is 0mm; 5) the laser processing mode is dynamic light type beam scanning mode; 6) the processing layer number 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.

[0051] S4, the thin-walled shaped part 17 (as shown in Figure 5-4

[0052] The above only describes the preferred embodiments of the present application, and does not use any restriction on the technical solutions of the present application, and those skilled in the art should understand that the technical solutions can be modified and replaced in several simple ways without departing from the spirit and principles of the present application, and these modifications and replacements also belong to the protection scope covered by the claims.​​​​

Claims

1. A method for cutting tiny group 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, divide the surface of the thin-walled curved part into N processing areas according to the processing area of ​​a single laser scan; the processing area is the laser focus automatic focus area, and the area of ​​the automatic focus area is no more than 60% of the field lens surface area; S2, automatically searching the laser focus for each processing area, and recording the focus position data of the laser beam scanning during automatic focusing into the processing program; S3, uses a dynamic laser field mirror beam to scan through a flat field lens to process tiny group holes, special-shaped holes on thin-walled curved parts, and scan and cut thin-wall contours; where the thickness of the thin-walled curved parts is less than 0.5mm; During processing, the circular air film hole processing program is first called to process the circular air film tiny holes 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 the contour of the thin-walled curved surface parts; 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; The layered processing method is adopted during processing, and the interlayer spacing between two adjacent layers is 0.005~0.02mm; During processing, the scanning time of a single layer of the galvanometer is 3000~60000ms, the scanning speed is 2000~20000mm / s, and the line spacing is 0.005~0.02mm; During processing, oxygen or argon is used as auxiliary gas, and the gas pressure is 0.6~1.0MPa; S4, clean and inspect the processed parts to obtain finished parts.

2. The method for cutting micro-holes and special-shaped holes of thin-walled curved parts based on laser field mirror beam scanning according to claim 1 is characterized in that: In S2, thin-walled curved 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 on the area to be measured through the quick-change fixture, and the laser rangefinder is used to automatically focus the laser focus on the area to be measured.

3. The method for cutting micro-holes and special-shaped holes of thin-walled curved parts based on laser field mirror beam scanning according to claim 2, characterized in that: During automatic focus search, multiple focus searches are performed in each processing area.

4. A product obtained by the method for cutting tiny group holes and special-shaped holes of thin-walled curved parts based on laser field mirror beam scanning according to any one of claims 1 to 3.

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