A laser impact curved surface imprinting micro-text positioning method and automatic film changing device

Abstract

The present application relates to the technical field of laser shock imprinting, and particularly refers to a laser shock curved surface imprinting micro-text positioning method and an automatic film changing device. The present application adopts an integrated contact film, performs same-position micro-text nanosecond etching with same size on adjacent contact films, and through a rubber transmission belt on a roller, the contact film is delivered to the same position, so that repeated imprinting of the micro-text can be performed, or a variable curved surface imprinting is performed by adjusting an X-Y axis positioning system, which avoids the phenomena of uneven and insufficient imprinting caused by deformation of the contact film, reduces errors such as misregistration imprinting caused by film vibration in the imprinting process, ensures the accuracy of multiple imprinting, and reduces the process flow.

Description

Technical Field

[0001] This invention relates to the field of laser shock embossing technology, specifically to a laser shock embossing method for positioning microtextures on curved surfaces and an automatic film changing device. Background Technology

[0002] Laser shock embossing (LSI) is a novel surface texture preparation technology that simultaneously enhances surface plasticity and controls surface morphology. It significantly improves the high-cycle fatigue performance of metals through residual compressive stress pre-setting and microstructure improvement, while also making uncontrollable surface morphology controllable. However, high-power-density laser shock embossing can easily cause significant plastic deformation of the microtextured contact film, while low-power-density laser shock embossing results in uneven and insufficient surface morphology imprinting. Therefore, the microtextured contact film needs to be constantly replaced. This not only makes the LSI process cumbersome but also introduces new problems, namely, the automatic positioning of the microtexture and the consistency of the imprinted texture after contact film replacement. Furthermore, the placement, adjustment, and replacement of the contact film on curved workpieces present significant challenges. Summary of the Invention

[0003] To address the aforementioned problems, the present invention aims to provide an automatic film changing device and a microtexture positioning method, thereby solving the problems of cumbersome process flow and precise microtexture positioning caused by changing curved contact films during laser impact curved surface imprinting.

[0004] To address the above problems, the present invention provides the following technical solution:

[0005] An automatic film-changing device for laser impact curved surface embossing is characterized in that the device includes a micro-textured contact film, rollers, couplings, sliders, blocking blocks, slider vertical displacement servo motors, ball screws, roller rotation servo motors, guide rails, rotating shafts, support seats, XY-axis positioning systems, and positioning baffles.

[0006] The device is fixed to the horizontal workbench by bolts on the support base.

[0007] The XY-axis positioning system is also placed on a horizontal worktable, below the microtextured contact film held between the rollers.

[0008] The device is characterized in that it comprises four roller groups, totaling eight rollers, such as... Figure 1As shown, the rollers are connected to roller rotation servo motors via connecting rods and couplings. A positioning baffle with its own bearing is fixed to the rear end of each roller. The rotation servo motors connected to each roller rotate at the same speed. Two sets of rollers are fixed together at the top and bottom using elastic rubber transmission belts to achieve smooth rotation. The roller rotation servo motors are fixed to a slider, which is mounted on a ball screw. A slider vertical displacement servo motor is mounted on the slider to control its vertical displacement on the ball screw. The required thickness of the laser impact embossing contact film is adapted by adjusting the distance between the slider and the ball screw. After adapting to the contact film thickness, the distance between the two sliders on each ball screw remains unchanged, and the corresponding slider positions on each ball screw are the same. The ball screw is connected to the connecting rod, and the ball head at the end of the connecting rod is fixed to the guide rail by a fixing pin. The guide rail is marked with degrees for easy curvature adjustment. The guide rail is connected to the rotating shaft, which is fixed to the support base. The rotating shaft used is a type with automatic reset and limit functions, and it is marked with rotation degrees. The curvature control of the contact film is achieved by rotating the guide rail and moving the ball head on the guide rail. At the same time, the speed of the roller rotation servo motor can be adjusted to achieve quick film replacement.

[0009] Before performing laser impact embossing on curved surfaces using the aforementioned device, the position of the microtexture needs to be preset to achieve positioning, i.e., using an integrated contact film, such as... Figure 3 As shown, the integrated contact film consists of multiple impact zones and buffer zones. A buffer zone is provided between two adjacent impact zones, and a guide groove is provided within the buffer zone. A nanosecond laser is used to etch microtextures of the same size and structure at the same position in adjacent impact zones. After the contact film is laser-impacted at the previous station, the ball head is restored to its initial position on the guide rail, and the rotating shaft is also reset. Then, a new contact film is transported to the same position on the sample requiring imprinting via rollers and an elastic rubber conveyor belt. The positions of the rotating shaft and ball head on the guide rail are then sequentially adjusted to the previous imprinting positions. A positioning baffle with its own bearing is fixed behind the rollers to ensure proper alignment during curvature adjustment. The contact membrane does not shift. When repositioning the microtexture, the guide groove is used to overlap with the previous imprinting texture for misaligned imprinting. The guide groove is a through structure of the contact membrane, which is processed together with the microtexture and is on the same straight line as the side texture on the membrane surface. The deviation of the microtexture is corrected by adjusting the XY axis positioning system and imprinting at different positions to adapt to the repositioning of the texture after the surface is changed. By moving the four sets of sliders downward on the ball screw, the new contact membrane is made to fit tightly with the sample surface. This achieves automatic positioning of complex microtextures during continuous laser shock strengthening and ensures the consistency of microtexture imprinting after the contact membrane is replaced.

[0010] When the workpiece is large, the corresponding contact film will also be larger. The relative distance between the support seats can be increased accordingly, and the length of the rubber conveyor belt and the number of rollers can be appropriately increased to ensure the stability of the transmission and impact process.

[0011] The integrated contact membrane used has a buffer zone between adjacent impact zones to prevent the deformation of the contact membrane caused by the shock wave from indirectly affecting the surface texture morphology of the next contact membrane.

[0012] The nanosecond laser used to ablate the surface microtexture has a spot diameter of 50µm, a pulse width of 200ns, a velocity of 200mm / s, a power of 600W, and a frequency of 200kHz.

[0013] The integrated contact membrane is made of 60Si2CrVA high-elasticity spring steel. After nanosecond laser etching of the microtexture, it undergoes conventional polishing and ultrasonic cleaning before experimental operation. This invention will not be described in detail.

[0014] The beneficial effects of this invention are as follows:

[0015] The laser impact curved surface imprinting microtexture positioning and automatic film changing device designed by this invention can not only adjust the speed of the rotary servo motor to achieve rapid replacement of the contact film, but also ensure that the groove of the contact film after replacement is consistent with the previous station, and promptly replace the microtexture contact film that has undergone plastic deformation due to high power density laser impact, thus avoiding undesirable phenomena such as uneven surface morphology caused by insufficient laser impact curved surface imprinting.

[0016] The adjustment of the rotating shaft and ball head on the guide rail transforms the flat contact film into a curved contact film, providing a curved embossing device that solves the cumbersome process of changing the contact film when performing curved embossing.

[0017] By displacing the slider on the ball screw, the device can adapt to the replacement of contact films of different thicknesses, and the micro-textured contact film adheres more tightly to the sample surface. At the same time, due to the pressing effect of the elastic rubber band, the misalignment imprinting error caused by adverse vibration during the imprinting process is effectively reduced.

[0018] By pre-etching microtextures at the same position on adjacent contact films of an integrated contact film, and then transferring the new contact film to the position of the contact film at the previous station via a rubber belt, the complex microtextures can be automatically positioned during continuous laser shock peening, ensuring the consistency of microtexture imprinting after the contact film is replaced.

[0019] The integrated contact film used has a buffer zone between adjacent contact films to prevent the shock wave from propagating on the contact film and causing poor elastic-plastic deformation of the contact film in the next station. The resulting micro-deformation of the texture will eventually lead to a decrease in the embossing accuracy.

[0020] The integrated contact film used has a guide groove in its buffer zone, which is processed together with the microtexture and is aligned with the side texture on the film surface. This helps to control the positioning of the microtexture, and adjacent contact films are pulled by the guide groove to perform staggered imprinting.

[0021] The curvature is coarsely adjusted by rotating the shaft, and then finely adjusted by using the position of the ball head on the guide rail, thus enabling automatic film changing for multi-curved surface laser impact embossing. Attached Figure Description

[0022] Figure 1 A simplified 3D diagram of an automatic film-changing device for laser impact embossing of curved surfaces;

[0023] Figure 2 This is a simplified two-dimensional automatic membrane changing diagram of the device;

[0024] In the figure: 1 Microtextured contact membrane, 2 Roller, 3 Coupling, 4 Slider, 5 Stop block, 6 Slider up and down displacement servo motor, 7 Ball screw, 8 Roller rotation servo motor, 9 Guide rail, 10 Rotating shaft, 11 Support base, 12 Workpiece, 13 Horizontal worktable, 14 X-Y axis positioning system, 15 Positioning baffle, 16 Ball head.

[0025] Figure 3 The integrated contact membrane used in this invention has a guide groove that is a through-structure of the contact membrane. It is processed together with the texture and is on the same straight line as the side texture on the membrane surface. Detailed Implementation

[0026] To better illustrate the implementation details of the present invention, the technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] The present invention provides a laser-impact embossing microtexture positioning and automatic film changing device, such as... Figure 1 , 2 As shown, the device includes roller 2, coupling 3, slider 4, stop block 5, slider up / down displacement servo motor 6, ball screw 7, roller rotation servo motor 8, guide rail 9, rotating shaft 10, support base 11, XY axis positioning system 14, positioning baffle 15, and ball head 16. This device is not limited to the following example; when the workpiece is large, the corresponding contact film will also be large, which can be achieved by increasing the relative distance between the four support bases and appropriately increasing the number of rollers between the rubber conveyor belts.

[0028] Implementation Example 1:

[0029] In this embodiment, the microtextured contact film is made of 0.1mm thick 60Si2CrVA high-elasticity spring steel. Before inputting the contact film, a nanosecond laser is used to etch microtextures of the same size and structure at the same positions of adjacent impact zones on the integral contact film. The specific experimental steps are as follows:

[0030] Step 1: When feeding the film, align the two sides of the contact film with the outer side of the roller to make the film feeding process smoother. Use the displacement of the slider 4 on the ball screw 7 to clamp the contact film. Rotate the servo motor 8 slowly forward to transport the contact film above the workpiece.

[0031] Step 2: Scan the surface data through the computer-aided control system, and control the rotating shaft 10 to rotate the guide rail 9 for coarse curvature adjustment. Then, use the ball head 16 to move on the guide rail 9 for fine curvature adjustment and fix it with the positioning pin. The slider 4 moves down, while the distance between each group of sliders remains unchanged until the contact film is in close contact with the sample surface.

[0032] Step 3: After the first set of laser shock embossing is completed, the overall slider moves upward while maintaining the spacing, so that the contact film separates from the sample. First, adjust the ball head 16 back to its original position, and then reset the rotating shaft 10.

[0033] Step 4: Start the rotary servo motor 8 to output the previous contact film and input the new contact film to the same position as the previous contact film. Then, adjust the position of the rotating shaft 10 and the ball head 16 on the guide rail 9 to the position of the previous imprint. Move the four sets of sliders downward on the ball screw 7 so that the new contact film is closely attached to the sample surface, thus achieving the purpose of precise positioning of the microtexture.

[0034] The surface microtexture width was measured to be 51µm after the experiment. The above experimental process was repeated, and the new contact film was input to the previous imprinting location using guide lines and XY axis positioning system 14. After laser shock imprinting on the surface after surface transformation, the microtexture width at the surface junction was measured to be 50.7µm after the experiment.

Claims

1. An automatic film-changing device for laser impact curved surface embossing, characterized in that, The device includes rollers, couplings, sliders, slider vertical displacement servo motors, ball screws, roller rotation servo motors, guide rails, shafts, support bases, XY-axis positioning systems, and positioning baffles. The XY-axis positioning systems are placed on a horizontal worktable, below the micro-textured contact membrane clamped between the rollers. Eight rollers form four roller groups. The rollers are connected to the roller rotation servo motors via connecting rods and couplings. Positioning baffles with built-in bearings are fixed to the rear ends of the rollers. The rotation servo motors connected to each roller rotate at the same speed. An elastic rubber transmission belt fixes the upper and lower roller groups together to achieve smooth rotation. The roller rotation servo motors are fixed to the sliders, which are mounted on the ball screws. A slider vertical displacement servo motor is mounted on the slider to control the slider's vertical movement relative to the ball screw. The vertical displacement of the lever is adjusted by regulating the distance between the sliders on the ball screw to adapt to the required thickness of the laser impact embossing contact film. After adjusting the distance between the upper and lower sliders of the ball screw to adapt to the contact film thickness, the distance between the two sliders on each ball screw remains unchanged, and the corresponding slider positions on each ball screw are the same. The ball screw is connected to the connecting rod, and the ball head at the end of the connecting rod is fixed to the guide rail by a fixing pin. The guide rail is marked with degrees for easy curvature adjustment. The guide rail is connected to the rotating shaft, which is fixed to the support base. The rotating shaft used is a type with automatic reset and limit functions, and it is marked with rotation degrees. The curvature control of the microtextured contact film is achieved by rotating the guide rail and moving the ball head on the guide rail. At the same time, the film can be changed quickly by adjusting the speed of the roller rotation servo motor.

2. The automatic film-changing device for laser impact curved surface embossing as described in claim 1, characterized in that, The device is fixed to the horizontal workbench by bolts on the support base.

3. The automatic film-changing device for laser impact curved surface embossing as described in claim 1, characterized in that, When the workpiece is large, the corresponding contact film will also be larger, requiring an increase in the relative distance between the supports and an increase in the length of the rubber conveyor belt and the number of rollers to ensure the stability of the transmission and impact process.

4. A method for positioning laser-impregnated curved surface microtextures using the apparatus as described in claim 1, characterized in that, The microtextured contact film is a one-piece design, consisting of multiple impact zones and buffer zones. A buffer zone is located between two adjacent impact zones, and a guide groove is provided within the buffer zone. A nanosecond laser is used to etch microtextures of the same size and structure at the same location on adjacent impact zones. After the laser impact imprinting of the contact film at the previous station, the ball head is returned to its initial position on the guide rail, and the rotating shaft is also reset. A new contact film is then transported to the same imprinting position on the sample via rollers and an elastic rubber conveyor belt. The positions of the rotating shaft and ball head on the guide rail are then sequentially adjusted to the previous imprinting positions. A positioning baffle with a built-in bearing is fixed behind the rollers to ensure curvature. During the adjustment process, the contact film will not shift. When repositioning the microtexture, the guide groove is used to overlap with the previous imprinting texture for misaligned imprinting. The guide groove is a through structure of the contact film, which is processed together with the microtexture and is on the same straight line as the side texture on the film surface. The deviation of the microtexture is corrected by adjusting the XY axis positioning system and imprinting at different positions to adapt to the repositioning of the texture after the surface is changed. By moving the four sets of sliders downward on the ball screw, the new contact film is made to fit tightly with the sample surface. This achieves automatic positioning of complex microtextures during continuous laser shock strengthening and ensures the consistency of microtexture imprinting after the contact film is replaced.

5. The method as described in claim 4, characterized in that, The nanosecond laser used to ablate the surface microtexture has a spot diameter of 50µm, a pulse width of 200ns, a velocity of 200mm / s, a power of 600W, and a frequency of 200kHz.

6. The method as described in claim 4, characterized in that, The integrated contact membrane is made of 60Si2CrVA high-elasticity spring steel. After nanosecond laser etching of the microtexture, it is polished and ultrasonically cleaned before experimental operation.

Images