A double-sided laser shot peening additive manufacturing apparatus and method

Abstract

The application discloses a double-sided laser shot peening cumulative forming device and method, which comprises a laser shot peening system, a motion control system, an information acquisition system, a sample rotating system and the like. The application solves the problem of inconsistent curvature change of plate deformation when single-sided and single-time shot peening is performed. The method utilizes a rotating clamping system to realize interval shot peening of the double sides of the plate, combines cumulative forming and concave-convex deformation modes, sets an energy gradient of a shot peening surface, and realizes real-time monitoring of a shot peening process and adjustable parameters, so that the curvature of plate deformation can be greatly improved, and the deformation precision can be improved.

Description

Technical Field

[0001] This invention belongs to the field of laser peening technology, specifically relating to a double-sided laser peening cumulative forming device and method. Background Technology

[0002] High-precision, high-performance forming of wall panels is one of the key technologies in the manufacturing of major equipment, and also an important common technology in the manufacturing field. Key components of equipment such as airfoils, train nose wings, and ship hull plates not only determine the shape of the equipment, but also have a significant impact on the overall performance and lifespan of the equipment. The key to their manufacturing lies in the integral forming of complex wall panels.

[0003] Due to the limitations of laser energy, the curvature of sheet metal forming is greatly restricted. Currently, prestress-assisted forming methods are often used to improve the degree of deformation. However, this method involves complex equipment and cumbersome operation. Therefore, it is necessary to innovate laser shot peening forming methods. Summary of the Invention

[0004] The purpose of this invention is to provide a double-sided laser shot peening cumulative forming device and method, which has advantages such as high forming accuracy, large deformation degree, high degree of automation, and convenience.

[0005] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows: a double-sided laser shot peening cumulative forming device, comprising a laser shot peening system, a three-dimensional moving platform, and a workpiece. One of the surfaces of the workpiece to be processed faces the laser shot peening system. A vertical platform is fixed on the three-dimensional moving platform. An upper connecting device and a lower connecting device for a built-in motor are installed on the vertical platform. The upper and lower connecting devices for the built-in motor are respectively connected to the vertical platform sliding joint. A circular upper half-track is fixedly installed on the upper connecting device for the built-in motor, and a circular lower half-track is fixedly installed on the lower connecting device for the built-in motor. An upper clamp is installed in the circular upper half-track, and a lower clamp is installed in the circular lower half-track. The upper half of the four surfaces of the workpiece is clamped by the upper clamp, and the lower half of the four surfaces of the workpiece is clamped by the lower clamp. The 180° rotation switching of the two surfaces to be processed on the workpiece is achieved by simultaneously controlling the rotation angle of the upper clamp in the circular upper half-track and the rotation angle of the lower clamp in the circular lower half-track.

[0006] In the above scheme, the upper clamp includes four upper rotating wheels, each of which is connected to the circular upper half track rotating pair. A first upper housing is fixedly installed on each upper rotating wheel. A first upper coil is installed inside the first upper housing. The first upper housing is connected to a second upper housing through an upper spring. A second upper coil is installed inside the second upper housing. An upper fixed wheel is installed on the second upper housing. The upper half of the workpiece is located in the middle of the four upper fixed wheels.

[0007] In the above scheme, the lower clamp includes four lower rotating wheels, each of which is connected to the circular lower half track rotating pair. A first lower housing is fixedly installed on each of the lower rotating wheels. A first lower coil is installed inside the first lower housing. The first lower housing is connected to a second lower housing through a lower spring. A second lower coil is installed inside the second lower housing. A lower fixed wheel is installed on the second lower housing. The lower half of the workpiece is located in the middle of the four lower fixed wheels.

[0008] In the above solution, a movable tray is provided below the workpiece, the movable tray is fixed on a sliding platform, and a motor is installed on the sliding platform.

[0009] In the above scheme, the laser shot peening strengthening system includes a pulsed laser, a first reflecting mirror, a second reflecting mirror, and a focusing lens. The laser beam emitted by the pulsed laser is reflected by the first and second reflecting mirrors and then focused onto the surface of the workpiece by the focusing lens. A nozzle and a three-dimensional scanner are arranged near the workpiece.

[0010] This invention also provides a method for double-sided laser shot peening cumulative forming, comprising the following steps: S1: After grinding the workpiece, an absorption layer is applied to both sides and placed between the upper and lower clamps; S2: The power is turned on, and the first upper coil, second upper coil, first lower coil, and second lower coil are controlled to generate an induced magnetic field. The repulsive force drives the upper and lower springs to extend, thereby clamping the upper and lower halves of the workpiece; S3: The four upper rotating wheels and four rotating wheels are adjusted to rotate synchronously, so that the surface of the workpiece to be processed is perpendicular to the laser incident path; S4: The nozzle and laser are turned on, and the three-dimensional moving platform controls the movement of the workpiece. The workpiece is laser shot peened. After the workpiece completes shot peening of one strip area, the three-dimensional scanner measures the curvature change of the back area of ​​the impact surface, analyzes the curvature, and adjusts the laser parameters for the next strip area; S5: The four upper rotating wheels and four rotating wheels are adjusted to rotate synchronously, so that the workpiece is rotated 180 degrees. Then the pallet is moved, so that the workpiece moves upward by one strip spacing. The laser parameters are adjusted, and S4 is repeated. S6: After completing all strip shot peening areas, adjust the power supply and clamping force, and move the tray downwards to allow the sample to slide back to its initial position. S7: Repeat S2-S6 to complete the sample accumulation and forming process until the curvature meets the set requirements.

[0011] In the above scheme, when the workpiece is a flat workpiece, one side is laser-peened with a low energy laser (1-3J) and a spot diameter of 2-3mm, causing the workpiece to bend convexly away from the laser incident direction. The other side of the workpiece is laser-peened with a high energy laser (50-100J) and a spot diameter of 5mm-8mm, causing the workpiece to bend concavely towards the laser incident direction.

[0012] In the above scheme, when the workpiece is a plate with stiffeners, the side without stiffeners is laser shot peening with a low energy laser (1-3J, spot diameter 2-3mm), causing the plate to bend convexly away from the laser incident direction. The side with stiffeners can be laser shot peened with the same energy, or with a high energy laser (50-100J), causing the stiffener plate to bend concavely towards the laser incident direction.

[0013] In the above scheme, the overlap rate of the laser spots in all strip areas gradually increases from the edge of the board to the inside of the board, and the overlap rate gradually increases from 10% to 50%.

[0014] In the above scheme, the strip width on the workpiece is 3-10mm, and the strip spacing width is 3-10mm.

[0015] The beneficial effects of the present invention are as follows: (1) The present invention solves the problem of small curvature of plate deformation and inconsistent plate curvature changes when shot peening on one side and in one pass by using a special fixture and an automatic laser shock processing method after 360° automatic rotation of the workpiece. (2) The method uses a rotating clamping system to realize double-sided interval shot peening of the plate, combining cumulative forming and concave-convex deformation modes, setting the energy gradient of the shot peening surface, real-time monitoring of the shot peening process, and adjustable parameters, which can greatly improve the curvature of plate deformation and improve deformation accuracy. Attached Figure Description

[0016] Figure 1 Schematic diagram of the experimental setup.

[0017] Figure 2 The upper part of the sample rotation system.

[0018] Figure 3 The lower half of the sample rotation system.

[0019] Figure 4 Schematic diagram of double-sided laser shot peening. Detailed Implementation

[0020] The technical solution of the present invention will now be described in more detail with reference to the accompanying drawings.

[0021] like Figure 1As shown, this embodiment provides a double-sided laser shot peening cumulative forming device, including a laser shot peening system, a motion control system, an information acquisition system, and a sample rotation system. The laser shot peening strengthening system includes a pulsed laser 6, a first reflecting mirror 5, a second reflecting mirror 8, a focusing lens 10, a water tank 3, and a water valve 4. The laser beam emitted by the pulsed laser 6 is reflected by the first reflecting mirror 5 and the second reflecting mirror 8 and then focused onto the surface of the workpiece 9 by the focusing lens 10. The motion control system includes a three-dimensional moving platform 15, a vertical platform 17, a motion controller 11, a motion controller 2 16, a motion controller 2 19, a computer 1, a sliding platform 12, a motor 13, and a moving tray 14. One of the surfaces of the workpiece to be processed faces the laser shot peening system. A vertical platform 17 is fixed on the three-dimensional moving platform 15. An upper connecting device 28 and a lower connecting device 37 for the built-in motor are mounted on the vertical platform 17. The upper connecting device 28 and the lower connecting device 37 for the built-in motor are respectively connected to the sliding joint of the vertical platform 17. The information acquisition system includes a computer 1 and a three-dimensional scanner 18. The sample rotation system consists of an upper clamp and a lower clamp.

[0022] like Figure 2 and Figure 3 As shown, the sample rotation system includes an upper connecting device 28 for the built-in motor and a lower connecting device 37 for the built-in motor. A circular upper track 20 is fixedly installed on the upper connecting device 28, and a circular lower track 29 is fixedly installed on the lower connecting device 37. An upper clamp is installed inside the circular upper track 20, and a lower clamp is installed inside the circular lower track 29. Figure 2 As shown, the upper clamp includes four upper rotating wheels 23, each of which is connected to the circular upper half track 20 via a rotating joint. A first upper housing 21 is fixedly mounted on each upper rotating wheel 23. A first upper coil 24 is installed inside the first upper housing 21. The first upper housing 21 is connected to a second upper housing 26 via an upper spring 22. A second upper coil 25 is installed inside the second upper housing 26. An upper fixed wheel 27 is mounted on the second upper housing 26. The upper half of the workpiece is located in the middle of the four upper fixed wheels 27. Figure 3 As shown, the lower clamp includes four lower rotating wheels 32. Each lower rotating wheel 32 is connected to the circular lower half track 29 via a rotating pair. A first lower housing 30 is fixedly installed on each lower rotating wheel 32. A first lower coil 33 is installed inside the first lower housing 30. The first lower housing 30 is connected to a second lower housing 35 via a lower spring 31. A second lower coil 34 is installed inside the second lower housing 35. A lower fixed wheel 36 is installed on the second lower housing 35. The lower half of the workpiece is located in the middle of the four lower fixed wheels 36.

[0023] The upper half of the four sides of the workpiece is clamped by the upper fixture, and the lower half of the four sides of the workpiece is clamped by the lower fixture. The 180° rotation switching of the two sides of the workpiece to be processed is achieved by simultaneously controlling the rotation angle of the upper fixture in the circular upper track 20 and the rotation angle of the lower fixture in the circular lower track 29.

[0024] A method for double-sided laser shot peening cumulative forming includes the following steps: S1: After grinding, the workpiece 9 is coated with an absorption layer on both sides and placed between the upper and lower clamps; S2: The power is turned on, and the first upper coil 24, the second upper coil 25, the first lower coil 33, and the second lower coil 34 are controlled to generate an induced magnetic field. The repulsive force drives the upper spring 22 and the lower spring 31 to extend, thereby clamping the upper and lower halves of the workpiece 9; S3: The four upper rotating wheels 23 and the four lower rotating wheels 32 are adjusted to rotate synchronously, so that the surface of the workpiece 9 to be processed is perpendicular to the laser incident path; S4: The nozzle and laser are turned on, and the three-dimensional moving platform controls the movement of the workpiece 9, and the workpiece 9 enters the laser path. Laser peening is performed. After workpiece 9 completes peening of one strip area, the 3D scanner 18 measures the curvature change of the back area of ​​the impact surface, analyzes the curvature, and adjusts the laser parameters for the next strip area. S5: Adjust the four upper rotating wheels 23 and the four lower rotating wheels 32 to rotate synchronously, so that workpiece 9 completes a 180-degree rotation. Then move the tray to move workpiece 9 upward by one strip spacing. Adjust the laser parameters and repeat S4. S6: Continue until all strip peening areas are completed. Adjust the power supply and clamping force, and move the tray downward to allow the sample to slide back to the initial position. S7: Repeat S2-S6 to complete the cumulative forming of the sample until the curvature meets the set requirements.

[0025] Laser shot peening double-sided shot peening method, for flat surfaces, such as... Figure 4 As shown, one side is laser-peened with a low-energy laser (1-3J) and a spot diameter of 2-3mm, causing the plate to bend convexly away from the laser incident direction. The other side of the plate is laser-peened with a high-energy laser (50-100J) and a spot diameter of 5mm-8mm, causing the plate to bend concavely towards the laser incident direction. The combination of these two deformation mechanisms greatly improves the degree of bending deformation of the plate.

[0026] The laser shot peening double-sided shot peening method for stiffened plates involves using a low-energy laser (1-3J, 2-3mm spot diameter) on the unstiffened side to form the plate, causing a convex bend away from the laser incident direction. The stiffened side can be peened with the same laser energy, or with a high-energy laser (50-100J), causing the stiffened plate to bend concave towards the laser incident direction.

[0027] The overlap rate of the laser spot in the strip area gradually increases from the edge of the board to the inside of the board, and the overlap rate gradually increases from 10% to 50%.

[0028] A 3D scanner measures the back side of the surface after each strip shot peening process, providing greater accuracy. Based on the measured curvature, the laser shot peening parameters for the next strip are adjusted.

[0029] The shot peening method is double-sided interval shot peening, with a strip width of 3-10mm and an adjustable strip interval width of 3-10mm.

[0030] Specific implementation example: Take a flat plate with a thickness of 2mm as an example.

[0031] S1: After the sample is polished, the absorbent layer is attached to both sides and placed between the ring holders;

[0032] S2: Turn on the power, control the coil to generate an induced magnetic field, and clamp the sample.

[0033] S3: Adjust the upper and lower rotating wheels of the built-in engine to rotate synchronously so that the sample surface is perpendicular to the laser incident path. Set the laser energy to 3J, flat top light, laser wavelength to 20ns, spot diameter to 3mm, and overlap rate to gradually increase from 10% to 50% from the edge of the plate inward.

[0034] S4: Turn on the water valve and laser. The three-dimensional moving platform controls the movement of the sample. The sample is laser shot peened. After the sample completes shot peening of a strip area, the three-dimensional measuring instrument measures the curvature change of the back area of ​​the impact surface and analyzes the curvature to adjust the laser parameters of the next strip area.

[0035] S5: The upper and lower rotating wheels of the built-in engine rotate synchronously to complete the 180-degree rotation. Then move the tray so that the sample moves upward by one strip spacing. Adjust the laser parameters, set the laser energy to 50J, flat top light, laser wavelength to 20ns, spot diameter to 6mm, and the overlap rate to gradually increase from 10% to 50% from the edge of the plate inward. Repeat S4.

[0036] S6: After completing all strip shot peening areas, adjust the power supply, adjust the clamping force, and move the tray downwards so that the sample slides back to the initial position.

[0037] S7: Repeat S2-S6 to complete the sample accumulation and forming until the curvature meets the set requirements.

Claims

1. A double-sided laser shot accumulation forming method, comprising a laser shot system, a three-dimensional moving platform (15) and a workpiece, one of the surfaces of the workpiece to be processed faces the laser shot system, characterized in that, The three-dimensional moving platform (15) is fixed with a vertical platform (17), the vertical platform (17) is installed with an upper connecting device (28) and a lower connecting device (37) with built-in motors, the upper connecting device (28) and the lower connecting device (37) are respectively connected with the vertical platform (17) moving pair, the upper connecting device (28) is fixedly installed with a circular upper half track (20), the lower connecting device (37) is fixedly installed with a circular lower half track (29), the circular upper half track (20) is installed with an upper clamp, the circular lower half track (29) is installed with a lower clamp, the upper half of the four sides of the workpiece is clamped by the upper clamp, the lower half of the four sides of the workpiece is clamped by the lower clamp, the rotation angle of the upper clamp in the circular upper half track (20) and the rotation angle of the lower clamp in the circular lower half track (29) are controlled at the same time to realize the 180° rotation switching of the two sides of the workpiece to be machined; the upper clamp comprises four upper rotating wheels (23), each upper rotating wheel (23) is connected with the circular upper half track (20) rotating pair, each upper rotating wheel (23) is fixedly installed with a first upper housing (21), the first upper housing (21) is installed with a first upper coil (24), the first upper housing (21) is connected with a second upper housing (26) through an upper spring (22), the second upper housing (26) is installed with a second upper coil (25), the second upper housing (26) is installed with an upper fixed wheel (27), the upper half of the workpiece is located in the middle of the four upper fixed wheels (27); the lower clamp comprises four lower rotating wheels (32), each lower rotating wheel (32) is connected with the circular lower half track (29) rotating pair, each lower rotating wheel (32) is fixedly installed with a first lower housing (30), the first lower housing (30) is installed with a first lower coil (33), the first lower housing (30) is connected with a second lower housing (35) through a lower spring (31), the second lower housing (35) is installed with a second lower coil (34), the second lower housing (35) is installed with a lower fixed wheel (36), the lower half of the workpiece is located in the middle of the four lower fixed wheels (36); the lower part of the workpiece is provided with a moving tray (14), the moving tray (14) is fixed on the sliding platform (12), the sliding platform (12) is installed with a motor (13); the laser shot peening system comprises a pulse laser (6), a first reflector (5), a second reflector (8) and a focusing lens (10), the laser beam emitted by the pulse laser (6) is reflected by the first reflector (5) and the second reflector (8) and focused on the surface of the workpiece (9) through the focusing lens (10), a nozzle (7) and a three-dimensional scanner (18) are arranged near the workpiece (9); characterized by the following steps: S1: after the workpiece (9) is polished, the double-sided absorption layer is pasted, and is placed between the upper clamp and the lower clamp; S2: Turn on the power supply, control the first upper coil (24), the second upper coil (25), the first lower coil (33) and the second lower coil (34) to generate an induced magnetic field, and the repulsive force drives the upper spring (22) and the lower spring (31) to stretch to realize clamping of the upper half and the lower half of the workpiece (9); S3: Adjust the four upper rotating wheels (23) and the four lower rotating wheels (32) to rotate synchronously, so that the workpiece (9) to be processed is perpendicular to the laser incident path; S4: Turn on the nozzle and the laser, and control the three-dimensional moving platform to move the workpiece (9), and the workpiece (9) is subjected to laser peening forming, when the workpiece (9) completes a strip area peening, the three-dimensional scanner (18) measures the curvature change of the back surface area of the impact surface, and analyzes the curvature to adjust the laser parameters of the next strip area; S5: Adjust the four upper rotating wheels (23) and the four lower rotating wheels (32) to rotate synchronously, so that the workpiece (9) completes a 180-degree flip, then moves the tray, so that the workpiece (9) moves upward by one strip interval, adjusts the laser parameters, and repeats S4; S6: Until all strip peening areas are completed, adjust the power supply, adjust the clamping force, move the tray downward, so that the sample slides to the initial position; S7: Repeat S2-S6 to complete the cumulative forming of the sample, until the curvature meets the set requirements.

2. A method of double-sided laser peening additive manufacturing according to claim 1, wherein, When the workpiece is a flat plate workpiece, one side is subjected to laser peening forming by using small energy laser, the laser energy is 1-3 J, the spot diameter is 2-3 mm, the workpiece occurs convex bending away from the laser incident direction, and the other side of the workpiece is subjected to laser peening by using large energy laser with a laser energy of 50-100 J and a spot diameter of 5 mm-8 mm, and the workpiece occurs concave bending towards the laser incident direction.

3. A method of double-sided laser peening additive manufacturing according to claim 2, wherein, When the workpiece is a plate with a stiffened plate, one side without the rib is subjected to laser peening forming by using small energy laser, the laser energy is 1-3 J, the spot diameter is 2-3 mm, the plate occurs convex bending away from the laser incident direction, and the other side with the rib can be subjected to laser peening by using the same laser energy or large energy laser with a laser energy of 50-100 J, and the stiffened plate occurs concave bending towards the laser incident direction.

4. A method of double-sided laser peening additive manufacturing according to claim 3, wherein, The overlap rate of all strip areas laser spots gradually increases from the edge position of the plate to the inside of the plate, and the overlap rate gradually increases from 10% to 50%.

5. A method of double-sided laser peening additive manufacturing according to claim 4, wherein, The strip width on the workpiece is 3-10 mm, and the strip interval width is 3-10 mm.

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