CN100441360C - Laser drilling method and drilling device thereof - Google Patents

Abstract

The invention discloses a laser drilling method and a drilling device thereof. The workpiece is kept still, and a small hole D1 is processed first, and then a hole D2 with a diameter of (2/5)D3 to (3/4)D3 is processed. Finally, the required hole D3 is obtained by rotary cutting. The device includes interconnected lasers and their optical light guide parts, laser focusing mirror parts, etc.; from top to bottom, the laser focusing mirror parts are mainly X-axis, Y-axis 45-degree full reflection mirrors, upper rail frame, X-axis moving frame, middle Rail frame, Y-axis moving frame, focusing lens; X-axis moving frame can slide relatively along the X-axis of the upper rail frame, and Y-axis moving frame can relatively slide along the Y-axis of the middle rail frame. The hole diameter D3 suitable for drilling in the present invention is 0.5 mm to 2 mm, and the processing quality is high.

Description

Laser drilling method and drilling device thereof

technical field

The invention relates to a method for high-quality microhole processing by combining free laser pulses and modulated laser pulses and a device designed according to the method, belonging to the technical field of laser processing.

Background technique

Compared with other drilling methods, laser drilling has the advantages of flexible processing, low cost, fast processing speed, high efficiency, no contact, transmission in the air, high drilling depth-to-diameter ratio, processing any material, and environmental protection. It is widely used in drilling ceramics and composite materials, and can also drill holes with a series of diameters and a certain inclination angle in superhard and high-temperature alloy materials, such as the drilling of aircraft engine turbine blades.

At present, laser drilling methods mainly include replication method and rotary method. The replication method also includes single-pulse drilling and multi-pulse drilling. Single-pulse drilling is suitable for drilling blind holes in thin plate parts. Deep hole processing generally uses multi-pulse drilling, that is, a series of modulated pulses with narrow pulse widths are used for drilling. Drilling with acousto-optic modulated laser pulses can reduce a series of problems such as recasting layer, microcracks and large heat-affected zone in laser drilling, but the hole diameter is small and the drilling speed is slow, and it is difficult for Larger apertures can't help. Free-running laser pulse drilling is used, and the hole diameter is large, and the drilling speed is fast, but the quality of the hole is poor. Nowadays, when laser processing holes with larger apertures, the rotary method is often used, that is, the workpiece rotates around an axis that deviates from the center of the laser focus spot by a distance of D/2. When the rotation speed is slow (compared to the pulse laser emission frequency), it is equivalent to cutting, and a hole with an aperture D is cut on the workpiece after one revolution. However, the laser energy required for cutting holes by the rotary method is large, and the quality of the cut holes is relatively poor. Moreover, the existing laser cutting equipment is expensive and inefficient. The above points limit the development of laser processing technology.

Contents of the invention

The purpose of the present invention is to propose a laser drilling method using free laser pulses and modulated laser pulses and a drilling device designed to realize the method; The technical problem of poor quality of the large holes drilled solves the technical problems of recasting layer and micro-cracks and large heat-affected area in laser drilling.

The technical solution adopted by the present invention to solve the above object is as follows.

A laser drilling method is characterized in that: the step of laser drilling is:

1. Position the position on the workpiece that needs to be drilled, and adjust the position of the laser focusing mirror;

2. Adjust the output parameters of the laser according to the relationship between the diameter and depth of the workpiece to be drilled and the energy, and output the laser pulse with energy E ₁ ,

$\mathrm{<span\; class="notranslate">\; D.</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 2</span>}{<span\; class="notranslate">\; [</span>\frac{\mathrm{<span\; class="notranslate">\; 3</span>}\mathrm{<span\; class="notranslate">\; E.</span>}}{\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; B</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; ]</span>}^{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; ,</span>$ $\mathrm{<span\; class="notranslate">\; h</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 2</span>}{<span\; class="notranslate">\; [</span>\frac{\mathrm{<span\; class="notranslate">\; 3</span>}\mathrm{<span\; class="notranslate">\; E.</span>}}{\mathrm{<span\; class="notranslate">\; \&pi;<figure-callout\; id="2"\; label="t\; g"\; filenames="C20051013205500171.png"\; state="\{\{state\}\}">t</figure-callout></span><figure-callout\; id="2"\; label="t\; g"\; filenames="C20051013205500171.png"\; state="\{\{state\}\}">\; </figure-callout>}{\mathrm{<span\; class="notranslate">\; </span>}}^{}{\mathrm{<span\; class="notranslate">g</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; \&theta;</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; B</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; ]</span>}^{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; ,</span>$

In the formula, E is the laser energy (J), L _B is the vaporization specific energy of the workpiece material (J/cm ² ), L _M is the melting heat specific energy of the processed material (J/cm ² ), θ is the time when the laser enters the material The divergence half angle (rad), H is the depth of the laser drilling, that is, the thickness of the processed material, D is the aperture of the laser drilling, the output is a modulated laser pulse with high peak power, and the power range is 10 ⁶ W/CM ² ~ 10 ⁹ W/CM ² ;

3. Adopt suitable auxiliary gas according to the material properties of the workpiece, and output modulated laser pulses under the protection of the auxiliary gas to penetrate the workpiece to obtain a small hole _D1 ;

4. Readjust the output parameters of the laser, and the laser pulse to be emitted is a free-running laser pulse with an energy range of 5E ₁ to 10E ₁ ;

5. The position of the workpiece remains unchanged, and under the protection of the auxiliary gas, a free-running laser pulse is output, and drilling is continued on the basis of the small hole _D1 obtained in step [3] to obtain an aperture size range of $\frac{2}{5}{\mathrm{D.}}_3~\frac{3}{4}{\mathrm{D.}}_3$ hole _D2 ;

6. Adjust the output parameters of the laser again, and output the modulated laser pulse with energy E ₁ ;

7. The position of the workpiece remains unchanged. Under the protection of the auxiliary gas, the modulated laser pulse is output, the position of the laser focusing mirror is adjusted, the hole _D2 is rotary cut, the recast layer and microcracks on the hole wall are repaired, and the obtained The required aperture D ₃ .

The pore size of the pores _D1 of the present invention ranges from 50 to 300 μm.

A laser perforating device, comprising a laser 1 connected to each other and its optical light guide part 2, a CCD camera 3, a photodetector 5, a computer 6, a digital oscilloscope 7 and a laser focusing mirror part 4, directly above the laser focusing mirror part It is a CCD camera 3, the laser focusing mirror part is connected with the optical light guide part, and the photodetector 5 is on the side outside the upper part of the laser focusing mirror part, and its feature also includes: the laser focusing mirror part 4 is mainly from top to bottom X-axis 45-degree full reflection mirror 12 and Y-axis 45-degree full reflection mirror 13, upper rail frame 14, X-axis moving frame 25, middle rail frame 16, Y-axis moving frame 22, focusing lens 24; upper rail frame 14, X Axis moving frame 25, middle guide rail frame 16, and Y-axis moving frame 22 are all hollow structures, and the fixing seat at the bottom of the X-axis 45-degree full mirror passes through the upper rail frame 14 and is fixed on the X-axis moving frame 25, and the Y-axis is 45 degrees. The Y-axis laser light guide tube at the bottom of the full mirror 13 passes through the upper rail frame 14, the X-axis moving frame 25, the middle rail frame 16, and the Y-axis moving frame 22 to fix it, and the focusing lens 24 is fixed right below the Y-axis laser light tube The upper rail frame is fixed on the frame of the laser focusing mirror part, and the X-axis moving frame and the middle rail frame are fixed together; the X-axis moving frame 25 is connected with the upper rail frame 14, and the two are controlled by a computer 6 The drive mechanism of the drive mechanism slides relative to the X axis, the Y axis moving frame 22 is connected with the middle rail frame 16, and the drive mechanism controlled by the computer between the two slides relatively along the Y axis, the X axis axis and the Y axis axis They are perpendicular to each other; the lens of the X-axis 45-degree full-reflection mirror and the lens of the Y-axis 45-degree full-reflection mirror are facing each other. The direction of becomes perpendicular to the direction of the workbench

The laser beam passing between the two is parallel to the Y-axis axis.

The X-axis guide rail 31 of the present invention is installed on both sides of the bottom of the upper guide rail frame 14, and the Y-axis guide rail 17 is installed on both sides of the bottom of the middle guide rail frame 16; the Y-axis moving frame 22 passes through the Y-axis slider 21 and the Y-axis guide rail 17 In contact, the X-axis moving frame 31 is in contact with the X-axis slide block 30 and the X-axis guide rail 31 on it.

The X-axis driving mechanism of the present invention includes an X-axis motor fixed on the side of the upper guide rail frame 14, the X-axis motor synchronous wheel 20, and the X-axis screw synchronous wheel 15. Fixed Y-axis motor, Y-axis motor synchronous wheel 28 on the side of frame 22, Y-axis lead screw synchronous wheel 19; X-axis lead screw synchronous wheel 15 is connected with X-axis motor synchronous wheel 20 through synchronous belt; Y-axis lead screw The synchronous wheel 19 is connected with the Y-axis motor synchronous wheel 28 through a synchronous belt.

The present invention establishes an X-axis lead screw 26, one end of which is fixed on the shaft center of the X-axis lead screw synchronous wheel 15, and the other end is screwed into the X-axis lead screw nut 32, and the X-axis lead screw nut is fixed on one side of the X-axis moving frame 25. Side; establish a Y-axis lead screw 23, one end is fixed on the axis center of the Y-axis lead screw synchronous wheel 19, and the other end is screwed into the Y-axis lead screw nut 33 li, and the Y-axis lead screw nut is fixed on a part of the Y-axis moving frame 22 side.

The present invention has auxiliary gas nozzles 11 with constant relative positions around the focusing lens 24 .

The ranges of the relative moving distances of the X-axis moving frame 25 and the Y-axis moving frame 22 of the present invention are both 0-40 mm.

If only the X-axis motor is working or only the Y-axis motor is working, one-dimensional cutting can be realized, and two motors working at the same time can realize two-dimensional movement. Keep the X-axis direction screw and the Y-axis direction screw fixed, not only keep the focusing mirror still, and drill holes at rest; the two-axis motors work at the same time, driving the focusing mirror to move in two dimensions, and the movement path is the aperture that needs to be repaired.

The focusing mirror part realizes the combination of copy punching and rotary cutting punching.

The beneficial effects of the present invention are: compared with the rotary method, the focusing mirror rotary cutting method realizes laser pulse cutting with small energy; improves the precision of laser drilling, and can improve the efficiency of laser drilling, and can obtain a larger aperture; Moreover, it is more convenient to remove the material at the melting point of small size; the area affected by laser heat is reduced, the thickness of the recast layer is reduced, the roundness is high, the hole wall is straight and the surface is clean.

Description of drawings

Fig. 1 is the schematic diagram of the inventive method;

Fig. 2 is a schematic diagram of the overall structural framework of the device of the present invention;

Fig. 3 is a schematic diagram of punching holes by laser focusing mirror rotary cutting method;

Fig. 4 is a schematic diagram of laser rotary drilling;

Fig. 5 is a structural diagram of laser focusing mirror components of the present invention;

Fig. 6 is an exploded view of the structure of the laser focusing mirror part of the present invention;

Fig. 7 is a sectional view of laser focusing mirror part A-A of the present invention.

1. Laser 2. Optical light guide system 3. CCD camera 4. Focusing mirror component 5. Photoelectric detector 6. Computer 7. Digital oscilloscope 8. Workpiece 9. Workbench 10. Lens 1 11. Y-axis 45-degree full mirror Mirror frame 12. X-axis 45-degree full reflection mirror 13. Y-axis 45-degree full reflection mirror 14. Upper guide rail frame 15. X-axis screw synchronous wheel 16. Middle guide rail frame 17. Y-axis guide rail 18. Y-axis bearing 19. Y-axis screw synchronous wheel 20, X-axis motor synchronous wheel 21, Y-axis slider 22, Y-axis moving frame 23, Y-axis screw 24, focusing lens 25, X-axis moving frame 26, X-axis screw 27, Y Axis laser light guide 28, Y-axis motor synchronous wheel 29, X-axis bearing 30, X-axis slider 31, X-axis guide rail 32, X-axis screw nut 33, Y-axis screw nut 34, lens 2 35, protective lens

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings, implementation methods and examples.

In the implementation method shown in Figure 1, the hole diameter _D3 suitable for punching by this method is 0.5mm to 2mm, the small hole (aperture _D1 ) completed in the first step, and the hole (aperture _D2 ) completed in the second step , and finally obtain the hole (aperture D ₃ ) required for processing, the specific steps are:

First of all, according to the position of the workpiece that needs to be drilled, the position of the focusing lens is adjusted by using CCD positioning. According to the relational expression (I) of the aperture and depth and energy that workpiece needs to punch, adjust each input parameter of laser, control output power, output energy is _E Output small energy laser pulse as long as the hole is punched) laser pulse. According to different materials, compressed gas, nitrogen, argon or oxygen are used as auxiliary gas, and 1 to 3 laser pulses are output with high peak power (10 ⁶ W/CM ² ～10 ⁹ W/CM ² ) modulated laser pulses under gas protection The pulse penetrates the workpiece to obtain a small hole D ₁ with a diameter of 50-300μ.

Then readjust the frequency, pulse width, and input power of the laser, so that the output laser energy is 5E ₁ ~ 10E ₁ free-running laser pulse, the position of the focusing lens and the workpiece remains unchanged, and the hole is drilled under the protection of the auxiliary gas. The obtained aperture is D ₂ (the size is $\frac{2}{5}{\mathrm{D.}}_3~\frac{3}{4}{\mathrm{D.}}_3$ ) holes.

Because the existence of small holes in the first step can better prevent plasma shielding caused by the interaction between laser and metal vapor during the laser drilling process, reducing energy loss, and reducing metal deposition and microcracks on the hole wall , but the quality of the punched holes is still poor, and the shape of the holes is irregular.

Finally, the output energy is the modulated laser pulse of _E1 , and the X-axis 45-degree total reflection mirror 12 and the Y-axis 45-degree total reflection mirror 13 of the focusing mirror part are controlled by a servo motor to perform two-dimensional movement, and the focusing lens is rotated. The rotation speed of the motor can change the rotation range of the focusing lens to achieve the rotary cutting of the D ₂ hole by the moving rotating part of the focusing lens, repair the recast layer and micro cracks on the hole wall, and obtain the required aperture D ₃ .

Implementation method one:

If a small hole with a diameter of 1mm is drilled on a 0.7mm thick galvanized steel plate, firstly, use the CCD to position the hole according to the workpiece needs, and adjust the position of the focusing lens. Adjust the input parameters of the laser, control the output power, and output laser pulses with an energy of 0.3J. Under the protection of oxygen, a modulated laser pulse with a high peak power of 1.0×10 ⁹ W/cm ² is output to penetrate the workpiece with one pulse, and a small hole D ₁ with a diameter of 80 μm is obtained. Then readjust the frequency, pulse width, and input power of the laser, so that the output laser energy is a free-running laser pulse of 2J, and the positions of the focusing lens and the workpiece remain unchanged. Under the protection of the auxiliary gas, the hole is drilled to obtain an aperture of 0.7 mm hole D ₂ . Finally, output the modulated laser pulse with an energy of 0.3J, use the motor to control the X, Y axis 45-degree total reflection mirror 1 and 2 of the focusing mirror rotation movement system to make two-dimensional movement to drive the focus lens to rotate, and the X and Y axis 45-degree total reflection mirror Both 1 and 2 are Nd:YAG full reflection mirrors. By setting the rotation speed of the motor and changing the rotation range of the focus lens, the rotary cutting of the D ₂ hole by the moving rotating part of the focus lens is realized, and the recasting layer and the microscopic surface of the hole wall are repaired. Crack, and obtain the required hole diameter 1mm.

Embodiment two:

If a small hole with a diameter of 2mm is drilled on a low carbon steel with a thickness of 1.5mm, first of all, according to the position of the workpiece to be drilled, use the CCD to position and adjust the position of the focusing lens. Adjust the input parameters of the laser, control the output power, and output laser pulses with an energy of 2J. Under the protection of argon gas, output a modulated laser pulse with a high peak power of 3×10 ⁹ W/cm ² to penetrate the workpiece with one pulse, and obtain a small hole D1 with a diameter of 100 μm. Then readjust the frequency, pulse width, and input power of the laser, so that the output laser energy is a free-running laser pulse of 16J, and the position of the focusing lens and the workpiece remains unchanged. Under the protection of the auxiliary gas, the hole is drilled to obtain an aperture of 1.4 mm hole D ₂ . Finally, output the modulated laser pulse with an energy of 1J, and use the servo motor to control the X, Y axis 45-degree full mirrors 1 and 2 of the focusing lens rotation movement system to make two-dimensional movements to drive the focusing lens to rotate. By setting the rotation speed of the motor, Change the rotation range of the focusing lens to achieve the rotary cutting of the _D2 hole by the moving rotating part of the focusing lens, repair the recast layer and micro cracks on the hole wall, and obtain the required hole with a diameter of 2mm.

In the embodiment shown in FIG. 2 , the entire device includes an interconnected laser 1 and its optical light guiding part 2 , a CCD camera 3 , a photodetector 5 , a computer 6 , a digital oscilloscope 7 and a laser focusing mirror part 4 . Just above the laser focusing mirror part 4 is a CCD camera 3, the laser focusing mirror part is connected with the optical light guide part, and the photodetector 5 is on the outer side of the laser focusing mirror part.

In the laser focusing mirror rotary cutting method shown in Figure 3, d is the starting end of rotary cutting, e is the end of rotary cutting, and f is the path of rotary cutting. The third step of the drilling method uses this rotary cutting method, which is used to repair the holes punched in the first two steps.

In the drilling by the laser rotary method shown in Fig. 4, the workpiece rotates around an axis deviating from the center of the laser focus spot by a distance D/2. The workpiece is on the two-dimensional motion table, the focusing head does not move, the workpiece rotates with the platform, and the laser punches a hole with an aperture D on the workpiece. However, when the rotary method is used to cut holes, the laser energy required is relatively large, and the quality of the cut holes is poor. 10 of them is lens 1.

In the embodiment shown in Fig. 5, the focusing mirror part 4 mainly includes the X-axis 45-degree total reflection mirror 12 and the Y-axis 45-degree total reflection mirror 13 on the left side of the X-axis 45-degree total reflection mirror from top to bottom, and the upper guide rail Frame 14, X-axis moving frame 25, middle rail frame 16, Y-axis moving frame 22, focusing lens 24.

Refer to the exploded view of the structure of the laser focusing mirror components shown in FIG. 6 and the A-A sectional view shown in FIG. 7 .

The upper rail frame 14, the X-axis moving frame 25, the middle rail frame 16, and the Y-axis moving frame 22 are all hollow structures, and the fixed seat at the lower part of the X-axis 45-degree full mirror passes through the upper rail frame 14 and is fixed on the X-axis moving frame On 25, the Y-axis laser light guide tube at the bottom of the Y-axis 45-degree full reflection mirror 13 passes through the upper rail frame 14, the X-axis moving frame 25, the middle rail frame 16, and the Y-axis moving frame 22 is fixed, and the Y-axis laser light guide A focusing lens 24 is fixed just below the tube. The upper rail frame is fixed on the frame of the laser focusing mirror component, and the X-axis moving frame is fixed together with the middle rail frame.

The X-axis 45-degree full reflection mirror 12 is fixed above the X-axis moving frame 25 by screws, and moves together with the X-axis moving frame 25 . The Y-axis 45-degree total reflection mirror 13 is connected with the hollow cylindrical light guide tube 27 through screws, and the laser light guide tube is connected with the Y-axis moving frame 22 as a whole, and moves together with the Y-axis moving frame. The lens of the X-axis 45-degree full-reflection mirror and the lens of the Y-axis 45-degree full-reflection mirror are facing each other, and the Y-axis 45-degree full-reflection mirror is located on the left side of the X-axis 45-degree full-reflection mirror. The laser beam is parallel to the workbench. Finally, it becomes emitted in a direction perpendicular to the worktable, and the laser beam passing between the two is parallel to the Y axis.

The X-axis moving frame 25 is connected with the upper rail frame 14, and the two can slide relative to each other along the X-axis. The Y-axis moving frame 22 is connected with the middle rail frame 16, and can slide relative to each other along the Y-axis. The axis and the Y axis are perpendicular to each other. Four evenly distributed X-axis sliders 30 are in contact between the upper rail frame and the X-axis mobile frame, and four evenly distributed Y-axis sliders 21 are in contact between the middle rail frame and the Y-axis mobile frame.

The X-axis guide rail 31 is installed on both sides of the bottom of the upper rail frame; the X-axis motor synchronous wheel 20 and the X-axis lead screw synchronous wheel 15 are respectively fixed on the left and right sides of the lower part of the upper rail frame, and the X-axis motor is also fixed on the upper rail frame. Bottom, one end of X-axis leading screw 26 is fixed on the shaft center of X-axis leading screw synchronous wheel 15, and X-axis motor synchronous wheel is connected with X-axis leading screw synchronous wheel by synchronous belt.

The X-axis mobile frame is a cavity structure, and the bottom of the X-axis mobile frame is connected with the middle rail frame 16 outside the cavity, and the other end of the X-axis lead screw 26 is screwed into the X-axis lead screw nut 32 li. The slide block 30 is fixed above the X-axis moving frame and directly below the guide rail 31 . The X-axis lead screw nut 32 is fixed together with the left side of the X-axis moving frame, which changes the rotational motion of the X-axis lead screw 26 into its own motion in the X-axis direction, and drives the X-axis moving frame to move, thereby driving the X-axis slider 30 moves on the guide rail.

The Y-axis motor is fixed on the outside of the middle rail frame 16, and one end of the Y-axis leading screw 23 is fixed in the center of the shaft of the Y-axis leading screw synchronous wheel 19, and the other end of the Y-axis leading screw 23 is screwed into the Y-axis leading screw nut 33 li. Threads are provided in the bottom plate of the Y-axis moving frame to connect the focusing lens 24 .

The Y-axis lead screw nut 33 is fixed together with the rear side of the Y-axis movable frame, and converts the rotational motion of the Y-axis lead screw 23 into its own linear motion in the Y-axis direction, driving the Y-axis movable frame to move.

The X-axis motor synchronous wheel 20 and the Y-axis motor synchronous wheel 28 are connected to the X-axis and Y-axis motors respectively, and the X and Y motors adopt high-speed high-torque precision motors. Driven by the Y-axis motor, the Y-axis lead screw 23 drives the Y-axis moving frame 22 to move, and the slider 21 moves on the guide rail 17, thereby driving the Y-axis 45-degree total reflection mirror 13 and the focusing mirror 24 to move synchronously to realize the Y-axis direction. one-dimensional motion.

Both X and Y axis 45 degree full reflection mirrors are Nd:YAG full reflection mirrors, the laser travels to the X axis 45 degree full reflection mirror in a straight line, then reflects to the Y axis 45 degree full reflection mirror, and then passes through the Y axis 45 degree full reflection mirror After reflection, it is transmitted to the focusing mirror 24 through the light guide 27 to output the laser for processing. The camera lens of the X-axis 45-degree total reflection mirror 12 and the Y-axis 45-degree total reflection mirror 13 is always facing.

When only the X-axis motor synchronous wheel is running, except for the upper rail frame and the X-axis motor synchronous wheel and X-axis screw synchronous wheel fixed together with the upper rail frame, the other parts move together with the X-axis mobile frame, that is The Y-axis moving part moves synchronously with the X-axis moving part, and the X-axis 45-degree full-reflective mirror 12 and the Y-axis 45-degree full-reflective mirror 13 move in the same direction to ensure that the light always passes through the center of the two mirrors, and at the same time ensures that the The light always exits from the center of the focusing mirror, thus realizing one-dimensional movement in the X-axis direction.

When the Y-axis motor and the X-axis motor run at the same time, driven by the X-axis screw and the Y-axis screw, the X-axis moving frame and the Y-axis moving frame move at the same time, and the X-axis 45-degree full mirror 12 and the Y-axis 45 13 full-degree mirrors move at the same time, and the Y-axis 45-degree full-mirror moves in the same direction as the X-axis 45-degree full-mirror while moving in the direction of the Y-axis driven by the Y-axis screw nut to realize the focusing mirror. Two-dimensional movement ensures the cutting of round holes.

Claims (8)

1. A laser drilling method is characterized in that: the step of laser drilling is: [1]. Position the position on the workpiece that needs to be drilled, and adjust the position of the laser focusing mirror; [2]. According to the relationship between the diameter and depth of the workpiece to be drilled and the energy, adjust the output parameters of the laser, and output the laser pulse with energy E ₁ , $\mathrm{<span\; class="notranslate">\; D.</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 2</span>}{<span\; class="notranslate">\; [</span>\frac{\mathrm{<span\; class="notranslate">\; 3</span>}\mathrm{<span\; class="notranslate">\; E.</span>}}{\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; B</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 2</span>}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; ]</span>}^{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; ,</span>$ $\mathrm{<span\; class="notranslate">\; h</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 2</span>}{<span\; class="notranslate">\; [</span>\frac{\mathrm{<span\; class="notranslate">\; 3</span>}\mathrm{<span\; class="notranslate">\; E.</span>}}{\mathrm{<span\; class="notranslate">\; \&pi;t</span>}{\mathrm{<span\; class="notranslate">\; g</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; \&theta;</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; B</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 2</span>}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; ]</span>}^{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; ,</span>$ In the formula, E is the laser energy (J), L _B is the vaporization specific energy of the workpiece material (J/cm ² ), L _M is the melting heat specific energy of the processed material (J/cm ² ), θ is the time when the laser enters the material The divergence half angle (rad), H is the depth of the laser drilling, that is, the thickness of the processed material, D is the aperture of the laser drilling; the output is a modulated laser pulse with high peak power, and the power range is 10 ⁶ W/CM ² ~ 10 ⁹ W/CM ² ; [3]. According to the properties of the workpiece material, an appropriate auxiliary gas is used, and under the protection of the auxiliary gas, a modulated laser pulse with energy E1 is output to penetrate the workpiece to obtain a small hole _D1 ; [4]. Readjust the output parameters of the laser, and the laser pulse to be emitted is a free-running laser pulse with an energy range of 5E ₁ to 10E ₁ ; [5]. The position of the workpiece remains unchanged, and under the protection of the auxiliary gas, a free-running laser pulse is output, and drilling is continued on the basis of the small hole _D1 obtained in step [3] to obtain a range of aperture sizes for

hole _D2 ; [6]. Adjust the output parameters of the laser again, and the output energy is the modulated laser pulse of E ₁ ; [7]. The position of the workpiece remains unchanged. Under the protection of the auxiliary gas, adjust the position of the laser focusing mirror, and use the modulated laser pulse with the output energy E1 to rotary cut the hole _D2 to repair the recast layer on the hole wall And microcracks, and obtain the required pore diameter D ₃ . 2. A laser drilling method according to claim 1, characterized in that: the diameter of the small hole _D1 ranges from 50 to 300 μm. 3. A laser drilling device, comprising interconnected lasers (1) and optical light guide components (2), a CCD camera (3) for positioning the laser drilling position, and a photodetector (5) for detecting laser pulse output , a computer (6) for controlling, a digital oscilloscope (7) for displaying laser pulse signals and computer output signals, and a laser focusing mirror part (4), and a CCD camera (3) is directly above the laser focusing mirror part (4) , the focusing mirror part is connected with the optical light guide part, and the photodetector (5) is on the side outside the upper part of the laser focusing mirror part, and the feature also includes: the laser focusing mirror part (4) is mainly X from top to bottom Axis 45-degree full reflection mirror (12) and Y-axis 45-degree full reflection mirror (13), upper rail frame (14), X-axis moving frame (25), middle rail frame (16), Y-axis moving frame (22) , focusing lens (24); the upper rail frame (14), the X-axis moving frame (25), the middle rail frame (16), and the Y-axis moving frame (22) are all hollow structures, and the X-axis 45-degree full reflection mirror bottom The fixed seat passes through the upper guide rail frame (14) fixed on the working platform and is fixed on the X-axis moving frame (25), and the Y-axis laser light guide tube at the bottom of the Y-axis 45-degree full reflection mirror (13) passes through the upper rail frame (14), the X-axis mobile frame (25), the middle guide rail frame (16), and the Y-axis mobile frame (22) are fixed, and the focusing lens (24) is fixed directly below the Y-axis laser light guide; the upper rail frame is fixed on the On the frame of the laser focusing mirror part described above, the X-axis moving frame and the middle rail frame are fixed together; the X-axis moving frame (25) is connected with the upper rail frame (14), and the computer (6) controls the The X-axis driving mechanism slides relatively along the X-axis, the Y-axis moving frame (22) is connected with the middle rail frame (16), and the Y-axis driving mechanism controlled by the computer (6) makes relative sliding along the Y-axis. , the X-axis and the Y-axis are perpendicular to each other; the lens of the X-axis 45-degree full-reflection mirror and the lens of the Y-axis 45-degree full-reflection mirror are facing each other, and the laser beam passes through the X-axis 45-degree full-reflection mirror and the Y-axis 45-degree After the total reflection mirror, the direction parallel to the workbench becomes perpendicular to the workbench, and the laser beam passing between the two is parallel to the Y axis. 4. A laser drilling device according to claim 3, characterized in that: the X-axis guide rail (31) is installed on both sides of the bottom of the upper guide rail frame (14), and the Y-axis guide rail (17) is installed on the middle guide rail frame Both sides of the bottom of (16); the Y-axis mobile frame (22) contacts the Y-axis guide rail (17) through the Y-axis slide block (21) above it, and the X-axis mobile frame (31) passes through the X-axis slide block above it (30) is in contact with the X-axis guide rail (31). 5. A kind of laser drilling device according to claim 3, characterized in that: the X-axis drive structure includes an X-axis motor fixed on the side of the upper rail frame (14), an X-axis motor synchronous wheel (20), X-axis lead screw synchronous wheel (15); Described Y-axis driving structure comprises Y-axis motor fixed on the side of Y-axis mobile frame (22), Y-axis motor synchronous wheel (28), Y Axis lead screw synchronous wheel (19); X-axis lead screw synchronous wheel (15) is connected with X-axis motor synchronous wheel (20) via a synchronous belt; Y-axis lead screw synchronous wheel (19) is connected with Y-axis motor synchronous wheel (28) Connection via timing belt. 6. A kind of laser drilling device according to claim 3 or 5, characterized in that: an X-axis screw (26), one end is fixed on the axis of the X-axis screw synchronous wheel (15), the other end Screw in the X-axis lead screw nut (32), and the X-axis lead screw nut is fixed on one side of the X-axis moving frame (25); establish a Y-axis lead screw (23), and one end is fixed on the Y-axis lead screw synchronous wheel ( 19) in the center of the shaft, the other end is screwed into the Y-axis lead screw nut (33), and the Y-axis lead screw nut is fixed on one side of the Y-axis moving frame (22). 7. A laser drilling device according to claim 3, characterized in that: around the focusing lens (24) there is an auxiliary gas nozzle (11) with a constant relative position. 8. A laser drilling device according to claim 6, characterized in that: the relative moving distances of the X-axis moving frame (25) and the Y-axis moving frame (22) are both in the range of 0-40 mm.

Images