Laser-assisted mechanical drilling device for composite materials

Abstract

The application provides a kind of composite laser-assisted mechanical drilling device, including base platform, and workpiece chuck rotation unit, laser unit, laser-assisted mechanical composite processing unit and safety unit installed on base platform;Laser-assisted mechanical composite processing unit includes double-shaft movement mechanism, sleeve drilling mechanism and laser coupling focusing mechanism;The installation orientation correspondence of laser coupling focusing mechanism and sleeve drilling mechanism makes that the focused laser spot is located on the profile line of sleeve drilling circumferential cutting edge or is radially offset by a certain distance, and the focus plane of laser beam and the tool end face of sleeve drilling are accurately coupled by adjusting the position of focusing lens group, the adjustment of drilling position and drilling feed are realized by double-shaft movement workbench drive, and laser-mechanical composite drilling processing is completed.The application solves the defects problems such as high tool wear rate, hole wall layered damage and burr, fiber pull-out and other defects existing in traditional mechanical drilling, and can greatly improve drilling efficiency.

Description

Technical Field

[0001] This invention belongs to the field of composite material hole making, specifically relating to a composite material laser-assisted mechanical hole making device. Background Technology

[0002] With the deepening large-scale application of high-performance composite materials (hereinafter referred to as composites), represented by carbon fiber reinforced polymer (CFRP), traditional machining technologies face numerous challenges. Firstly, due to the significant anisotropy of composites, their properties vary with fiber orientation. For example, CFRP is composed of a laminate of hard, brittle carbon fibers and a soft resin matrix. During machining, carbon fibers are mainly removed through brittle fracture rather than plastic deformation, making the fiber-matrix interface prone to debonding and delamination defects. Secondly, the high hardness of carbon fibers (HV 2000-3000) causes severe tool wear, and the cutting force varies greatly depending on the fiber orientation; the cutting force between 0° and 90° fiber orientations can differ by 2-3 times, easily leading to uneven cutting. Especially for drilling holes in load-bearing composite structural components, large-diameter holes (diameter ≥ 10mm) in thick composite plates (thickness ≥ 20mm) commonly suffer from complex processes, high tool wear rates, hole wall delamination damage and burrs, fiber pull-out, and other defects, severely restricting processing efficiency and cost control.

[0003] Laser drilling, as an important application of laser technology, offers advantages over traditional mechanical drilling methods, including high processing efficiency, high automation, and no tool wear. It has already seen initial applications in the composite materials field. However, due to the anisotropic thermophysical properties of composites such as CFRP and the limited heat resistance of the resin matrix (typically <200℃), laser drilling is prone to defects such as pyrolysis delamination and excessive ablation, resulting in processing efficiency far lower than mechanical drilling. Especially for laser drilling of large-diameter holes in thick composite plates, the heat accumulation generated by laser scanning causes severe heat-affected zones and delamination at the hole exit. Furthermore, as the drilling depth increases, laser energy significantly attenuates, the heat-affected zone expands, and tapered holes form in the later stages of processing. This leads to poor hole quality, low processing accuracy, low processing efficiency, and small processing thickness, resulting in overall poor hole quality and hindering its large-scale industrial application. Summary of the Invention

[0004] This invention provides a laser-assisted mechanical hole-making device for composite materials, which solves the problems of high tool wear rate, hole wall delamination damage and burrs, fiber pull-out, etc. in traditional mechanical hole-making, as well as the problems of tapered holes and thermal delamination in existing laser hole-making, and can significantly improve hole-making efficiency.

[0005] This invention is achieved through the following technical solution:

[0006] A composite material laser-assisted mechanical hole-making device includes a base platform, and a workpiece chuck rotation unit, a laser unit, a laser-assisted mechanical composite processing unit, and a safety unit mounted on the base platform.

[0007] The composite workpiece to be processed is clamped on the workpiece chuck rotating unit, and the hole to be processed is located at the rotation center of the workpiece chuck rotating unit. The composite workpiece to be processed can be driven to rotate by the workpiece chuck rotating unit. The laser unit includes a laser with pulse output or quasi-continuous output, and a mirror group for beam output, beam expansion and collimation and transmission direction.

[0008] The laser-assisted mechanical composite processing unit includes a dual-axis motion mechanism, a nesting drill mechanism, and a laser coupling focusing mechanism. The dual-axis motion mechanism is mounted on a base platform and includes a dual-axis motion worktable capable of two-dimensional orthogonal linear motion. The two axes of the worktable are along the radial and axial directions of the workpiece to be processed, respectively. The nesting drill mechanism and the laser coupling focusing mechanism are mounted on the motion slide of the dual-axis motion worktable. The laser coupling focusing mechanism includes a focusing lens group and an XYZ three-axis focusing displacement stage. The laser beam output from the laser unit is spatially deflected multiple times before being incident on the focusing lens group. The focusing lens group is linked to the XYZ three-axis focusing displacement stage via a lens mount, enabling... The position of the focused laser spot can be precisely controlled in three-dimensional space. The nesting drill mechanism includes a nesting drill, a variable diameter sleeve, an auxiliary tool holder, and a tool post. The nesting drill is mounted on the tool post via the auxiliary tool holder, the variable diameter sleeve, and bolts. The tool post is securely connected to the top mounting plate of the dual-axis motion mechanism. The installation orientation of the laser coupling focusing mechanism and the nesting drill mechanism corresponds so that the focused laser spot is located on the contour line of the circumferential cutting edge of the nesting drill or radially offset by a certain distance. Furthermore, by adjusting the position of the focusing lens group, the focal plane of the laser beam is precisely coupled with the end face of the nesting drill tool. The drilling position is adjusted and the drilling feed is achieved by driving the dual-axis motion worktable, thus completing the laser-mechanical composite hole making process.

[0009] Furthermore, the workpiece chuck rotation unit includes a chuck, chuck pulleys, and chuck base for clamping the composite workpiece to be processed, as well as a motor, motor pulley, and tensioner for driving the chuck rotation. The chuck base is bolted to the base platform, and the chuck is bolted to the chuck base for clamping the composite workpiece to be processed. The chuck pulley is connected to the tail of the chuck by a key. The motor mounting plate is bolted to the base platform, and the motor is mounted on the motor mounting plate via a motor flange and bolts. The motor pulley is connected to the motor output shaft. The chuck pulley and the motor pulley are connected by a V-belt, and the tensioner is connected and fixed below the chuck base by a nut, so that the motor drives the composite workpiece to be processed to rotate and the hole to be processed is located at the center of the chuck rotation.

[0010] Further, a tool clamp matched with the shape and size of the composite workpiece to be processed is arranged on the chuck.

[0011] Further, the laser unit has a wavelength of 266nm, 355nm, 532nm or 1060-1070nm, a pulse width less than 500ms, an average power of 5W-500W, and a repetition frequency of 10kHz to 1GHz.

[0012] Further, the laser unit comprises multiple lasers with different wavelength parameters.

[0013] Further, the laser coupling and focusing mechanism realizes auxiliary mechanical composite machining of multiple laser beams through the arrangement of spatial beam combining or spectral beam combining mechanisms.

[0014] Further, the safety unit is arranged on the periphery of the laser auxiliary mechanical composite machining unit and comprises a safety switch, a guide rail mounting plate, a sliding block, a support block, a guide rail, a side acrylic plate, a protective cover and a top acrylic plate, which are used for realizing safety protection and observing the machining process; the guide rail mounting plate is fixed on both sides of the laser auxiliary mechanical composite machining unit through bolts, the sliding block and the guide rail are installed on the front and rear sides of the guide rail mounting plate through the support block, the protective cover is installed on the sliding block through bolts, the side acrylic plate and the top acrylic plate are fixed on the outer side and the top of the protective cover through bolts, the safety switch mounting plate is fixed on the outer side of the guide rail mounting plate through bolts, and the safety switch is installed on the safety switch mounting plate through bolts.

[0015] The application has the following beneficial effects:

[0016] 1. The composite laser auxiliary mechanical drilling device provided by the application rationally arranges a workpiece clamping rotary chuck, a sleeve drilling mechanism, a laser coupling and focusing mechanism and a matched double-shaft motion adjustment feeding mechanism in a compact space, and ingeniously realizes the composite application of the sleeve drilling and the pulsed laser on the rotating composite workpiece, and the mechanical and laser working mechanisms can be cooperatively and precisely adjusted to complete the drilling of the composite workpiece, which is a brand-new process device that has not been reported in the industry field.

[0017] 2. The laser auxiliary mechanical composite machining unit comprises a componentized double-shaft motion mechanism, a sleeve drilling mechanism and a laser coupling and focusing mechanism, has good adjustable ability for drilling position adjustment, drilling feeding rate and laser spot composite position, on one hand, reduces the cutting force required by the composite fibers through the synchronous micro-area preheating effect of the coupled laser beams, solves the problems of high tool wear rate, excessive cutting force leading to hole wall delamination damage and burrs, fiber pull-out and other defects in traditional pure mechanical drilling, and on the other hand, overcomes the defects of thick plate hole taper and energy attenuation caused by pure laser drilling, and significantly improves the drilling precision and efficiency through the synchronous feeding of the laser and the tool.

[0018] 3、The expandability of the present application is very good, the laser coupling and focusing mechanism can configure multiple lasers for the laser unit scene, through configuring corresponding spatial beam combining or spectrum beam combining mechanism, realizing the auxiliary mechanical composite processing of multiple laser beam coupling, such as setting ultrafast laser spot at the outer diameter of the hole wall, which can polish the hole wall synchronously, and improve the hole quality.

[0019] 4、The composite material laser auxiliary mechanical hole making device provided by the present application does not increase the process compared with the existing hole making method, and the device structure is simple and easy to popularize and use. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is the overall structure schematic diagram of the composite material laser auxiliary mechanical hole making device.

[0021] Figure 2 It is the workpiece chuck rotating unit structure schematic diagram of the composite material laser auxiliary mechanical hole making device.

[0022] Figure 3 It is the laser unit structure schematic diagram of the composite material laser auxiliary mechanical hole making device.

[0023] Figure 4 It is the laser auxiliary mechanical composite processing unit schematic diagram of the composite material laser auxiliary mechanical hole making device.

[0024] Figure 5 It is the safety unit schematic diagram of the composite material laser auxiliary mechanical hole making device.

[0025] Figure 6 It is the processing state schematic diagram of the composite material laser auxiliary mechanical hole making device. DETAILED DESCRIPTION

[0026] The present application will be further described in detail below in combination with the drawings and specific embodiments.

[0027] As Figure 1-6 shown, the present application provides a composite material laser auxiliary mechanical hole making device, which comprises a base platform 1, and a workpiece chuck rotating unit 2, a laser unit 3, a laser auxiliary mechanical composite processing unit 4 and a safety unit 5 installed on the base platform 1.

[0028] The base platform 1 provides support and fixing effect for the composite material laser auxiliary mechanical hole making device, and is provided with positions and mounting hole positions for placing the workpiece chuck rotating unit 2, the laser unit 3, the laser auxiliary mechanical composite processing unit 4 and the safety unit 5;

[0029] The workpiece chuck rotation unit 2 comprises a chuck 21 for clamping the composite workpiece to be processed, a chuck pulley 22 and a chuck base 23, and a motor 24 for driving the chuck rotation, a motor pulley 25 and a tensioner 26; wherein the chuck base 23 is bolted on the base platform, the chuck 21 is bolted on the chuck base 23 and used for clamping the composite workpiece to be processed, and the chuck pulley 22 is connected to the tail of the chuck 21 by a key; the motor mounting plate is bolted on the base platform 1, the motor 24 is bolted on the motor mounting plate through a motor flange, and the motor pulley 25 is connected with the output shaft of the motor 24; the chuck pulley 22 and the motor pulley 25 are connected through a group of V-shaped belts, and the tensioner 26 is connected and fixed below the chuck base 23 through a nut, so as to realize the rotation of the composite workpiece to be processed driven by the motor 24 and the positioning of the hole to be processed at the center of the chuck 23 rotation; preferably, a tool clamp matched with the shape and size of the composite workpiece to be processed is arranged on the chuck 23, so as to better realize the stable clamping of the composite workpiece on the chuck 23 and the positioning of the hole to be processed at the center of the chuck rotation;

[0030] The laser unit 3 comprises a pulsed output or quasi-continuous output laser 31, and a laser beam output, beam expansion and collimation, and transmission and turning mirror group 32; preferably, the laser wavelength can be 266nm, 355nm, 532nm or 1060-1070nm, the pulse width is less than 500ms, the average power can be in the range of 5W-500W, and the repetition frequency can be in the range of 10kHz to 1GHz (quasi-continuous); preferably, the laser unit can also include multiple lasers with different wavelength parameters to realize more wavelength and pulse width laser composite processing;

[0031] The laser-assisted mechanical composite machining unit 4 comprises a double-axis motion mechanism, a bushing drill mechanism and a laser coupling focusing mechanism. The double-axis motion mechanism is installed on the base platform 1 and comprises a double-axis motion workbench 41 capable of two-dimensional orthogonal linear motion. The two motion axes of the double-axis motion workbench 41 are respectively along the rotation radial direction and the axial direction of the composite material workpiece (i.e. the chuck) to be machined. The bushing drill mechanism and the laser coupling focusing mechanism are installed on the motion sliding table of the double-axis motion workbench 41. The laser coupling focusing mechanism comprises a focusing mirror group 42 and an XYZ three-axis focusing displacement table 43. The laser beam output from the laser unit 3 is incident on the focusing mirror group 42 through necessary spatial folding. The focusing mirror group 42 is linked with the XYZ three-axis focusing displacement table 43 through a mirror holder seat, so that the position of the focused light spot can be accurately controlled in three-dimensional space. The bushing drill mechanism comprises a bushing drill 44 (preferably a diamond bushing drill), a variable-diameter sleeve 45, an auxiliary tool holder 46 and a tool holder 47. The bushing drill 44 is installed on the tool holder 47 through the auxiliary tool holder 46, the variable-diameter sleeve 45 and bolts. The tool holder 47 is fastened and connected through a foundation nut and the top mounting plate of the double-axis motion mechanism. The installation orientation of the laser coupling focusing mechanism and the bushing drill mechanism corresponds to the fact that the focused laser spot is located on the profile line of the circumferential cutting edge of the bushing drill 44 or is radially offset by a certain distance (generally less than ±0.5 mm). The position of the focusing mirror is adjusted to accurately couple the focal plane of the laser beam and the tool end face of the bushing drill, so that the drilling position is adjusted and the drilling feed is realized through the driving of the double-axis motion workbench 41, and the laser-mechanical composite drilling machining is completed. Preferably, the laser coupling focusing mechanism can configure multiple lasers for the laser unit. Through the configuration of corresponding spatial beam combining or spectral beam combining mechanisms, the auxiliary mechanical composite machining of multiple laser beams can be realized, such as setting an ultrafast laser spot at the outer diameter of the hole wall to simultaneously polish the hole wall and improve the hole drilling quality.

[0032] The safety unit cover 5 is arranged outside the laser-assisted mechanical composite machining unit 4 and comprises a safety switch 51, a guide rail mounting plate 52, a sliding block 53, a support block 54, a guide rail 55, a side acrylic plate 56, a protective cover 57 and a top acrylic plate 58, which are used to realize safety protection and observe the machining process. The guide rail mounting plate 52 is fixed on both sides of the laser-assisted mechanical composite machining unit 4 through bolts. The sliding block 53 and the guide rail 55 are installed on the front and rear sides of the guide rail mounting plate 52 through the support block. The protective cover 57 is installed on the sliding block 53 through bolts. The side acrylic plate 56 and the top acrylic plate 58 are fixed on the outside and the top of the protective cover 57 through bolts. The protective cover 57 plays a role in safety protection and observation of the machining process. The safety switch mounting plate is fixed on the outside of the guide rail mounting plate 52 through bolts. The safety switch 51 is installed on the safety switch mounting plate through bolts.

[0033] The composite laser-assisted mechanical drilling device provided by the application can realize high efficiency and high quality drilling of a composite thick plate. The drilling process can be divided into two steps.

[0034] Step 1: The composite thick plate to be processed is fixed on the chuck 21 through a fixture clamp, and the biaxial motion mechanism is controlled by a PLC control motor to align the sleeve drill 44 fixed on the top mounting plate with the rotation center of the chuck 21.

[0035] Step 2: The position of the focusing mirror group 42 is adjusted by adjusting the XYZ three-axis focusing displacement table in the laser coupling focusing mechanism, so that the focal plane of the laser beam and the tool end face of the sleeve drill are accurately coupled, the biaxial motion workbench 41 is driven to realize the adjustment of the drilling position and the drilling feed, the laser-mechanical composite drilling processing is completed, the protective cover 57 is moved to trigger the safety switch 51, the entire device is powered on and starts processing, and through the limit switch, it is ensured that the sleeve drill 44 does not exceed the limit distance during processing, and finally the mechanical laser composite processing of the thick plate composite material is realized.

[0036] Through the laser mechanical drilling technology of the application, the CFRP composite material can be processed with low tool wear and high hole wall quality. As shown in the specific processing state Figure 6 The laser beam 48 is superimposed on the circumferential cutting edge of the sleeve drill 44, which plays a role of "plowing" and "edge cutting", can effectively reduce the mechanical cutting force, reduce tool wear, reduce defects such as tearing, delamination and burr of the CFRP hole wall, and improve the drilling quality. Through laser processing, the inner layer and the periphery of the processed area are not significantly heated or deformed, which is beneficial to maintain the original performance of the CFRP material, and the main cutting principle of the mechanical sleeve drilling can effectively reduce the hole taper. The application combines the composite advantages of laser and mechanical drilling, and is expected to develop into a new method for efficiently and high-quality preparing CFRP thick plate large holes.

[0037] It is obvious to those skilled in the art that the application can be changed in various ways, and such changes are not considered to be beyond the scope of the application. All such modifications obvious to those skilled in the art will be included in the scope of the present claims.

Claims

1. A laser-assisted mechanical hole-making device for composite materials, characterized in that, The system includes a base platform (1), a workpiece chuck rotation unit (2), a laser unit (3), a laser-assisted mechanical composite processing unit (4), and a safety unit (5) mounted on the base platform (1). The composite workpiece to be processed is clamped on the workpiece chuck rotation unit (2), and the hole to be processed is located at the rotation center of the workpiece chuck rotation unit (2). The composite workpiece to be processed can be driven to rotate by the workpiece chuck rotation unit (2). The laser unit (3) includes a laser (31) with pulse output or quasi-continuous output, and a mirror group (32) for beam output, beam expansion, collimation, and transmission steering. The laser-assisted mechanical composite processing unit (4) includes a dual-axis motion mechanism, a nesting drill mechanism, and a laser coupling focusing mechanism. The dual-axis motion mechanism is mounted on a base platform (1) and includes a dual-axis motion worktable (41) capable of two-dimensional orthogonal linear motion. The two motion axes of the dual-axis motion worktable (41) are respectively along the radial and axial directions of the composite workpiece to be processed. The nesting drill mechanism and the laser coupling focusing mechanism are mounted on the motion slide of the dual-axis motion worktable (41). The laser coupling focusing mechanism includes a focusing lens group (42) and an XYZ three-axis focusing displacement stage (43). The laser beam output from the laser unit (3) is incident on the focusing lens group (42) after multiple spatial folds. The focusing lens group (42) is linked with the XYZ three-axis focusing displacement stage (43) through the lens mount, so that the focused light... The position of the spot can be precisely controlled in three-dimensional space; the nesting drill mechanism includes a nesting drill (44), a variable diameter sleeve (45), an auxiliary tool holder (46) and a tool holder (47). The nesting drill (44) is mounted on the tool holder (47) through the auxiliary tool holder (46), the variable diameter sleeve (45) and bolts. The tool holder (47) is fastened to the top mounting plate of the dual-axis motion mechanism. The installation orientation of the laser coupling focusing mechanism and the nesting drill mechanism corresponds so that the focused laser spot is located on the outline of the circumferential cutting edge of the nesting drill (44) or radially offset by a certain distance. By adjusting the position of the focusing lens group (42), the focal plane of the laser beam and the tool end face of the nesting drill are precisely coupled. The drilling position is adjusted and the drilling feed is achieved by driving the dual-axis motion worktable (41), thus completing the laser-mechanical composite hole making process.

2. The composite material laser-assisted mechanical hole-making device according to claim 1, characterized in that, The workpiece chuck rotation unit (2) includes a chuck (21) for clamping the composite workpiece to be processed, a chuck pulley (22) and a chuck base (23), as well as a motor (24), a motor pulley (25) and a tensioner (26) for driving the chuck to rotate; the chuck base (23) is bolted to the base platform (1), the chuck (21) is bolted to the chuck base (23) and used to clamp the composite workpiece to be processed, and the chuck pulley (22) is connected to the tail of the chuck (21) by a key; The motor mounting plate is bolted to the base platform (1), and the motor (24) is mounted on the motor mounting plate via the motor flange and bolts. The motor pulley (25) is connected to the output shaft of the motor (24). The chuck pulley (22) and the motor pulley (25) are connected by a V-belt. At the same time, the tensioner (26) is connected and fixed below the chuck base (23) by a nut, so that the motor (24) drives the workpiece to be processed to rotate and the hole to be processed is located at the rotation center of the chuck (23).

3. The composite material laser-assisted mechanical hole-making device according to claim 2, characterized in that, The chuck (21) is equipped with tooling fixtures that match the shape and size of the composite workpiece to be processed.

4. The composite material laser-assisted mechanical hole-making device according to claim 1, characterized in that, The laser wavelength of the laser unit (3) is 266nm, 355nm, 532nm or 1060-1070nm, the pulse width is less than 500ms, the average power is 5W-500W, and the repetition frequency is 10kHz to 1GHz.

5. The composite material laser-assisted mechanical hole-making device according to claim 1, characterized in that, The laser unit (3) includes multiple lasers with different wavelength parameters.

6. The composite material laser-assisted mechanical hole-making device according to claim 5, characterized in that, Laser coupling and focusing mechanisms enable auxiliary mechanical composite processing by configuring spatial beam combining or spectral beam combining mechanisms to couple multiple laser beams.

7. The composite material laser-assisted mechanical hole-making device according to claim 1, characterized in that, The safety unit (5) is installed around the laser-assisted mechanical composite processing unit (4) and includes a safety switch (51), a guide rail mounting plate (52), a slider (53), a support block (54), a guide rail (55), a side acrylic plate (56), a protective cover (57), and a top acrylic plate (58) for safety protection and observation of the processing process. The guide rail mounting plate (52) is fixed to both sides of the laser-assisted mechanical composite processing unit (4) by bolts. The slider (53) and the guide rail (55) are installed on the front and rear sides of the guide rail mounting plate (52) by the support block. The protective cover (57) is installed on the slider (53) by bolts. The side acrylic plate (56) and the top acrylic plate (58) are fixed to the outside and top of the protective cover (57) by bolts. The safety switch mounting plate is fixed to the outside of the guide rail mounting plate (52) by bolts. The safety switch (51) is installed on the safety switch mounting plate by bolts.

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