Laser ultrasonic residual stress detection device

Abstract

The utility model relates to the technical field of residual stress detection, in particular to a laser ultrasonic residual stress detection device which comprises a machine table, a laser emitting mechanism arranged on the machine table and used for emitting excitation laser to the surface of a component and a receiving mechanism used for receiving ultrasonic signals. The machine table is provided with an industrial personal computer, the receiving mechanism comprises an organic glass wedge block attached to the surface of the component and an ultrasonic receiving transducer arranged on the organic glass wedge block, and the ultrasonic receiving transducer is electrically connected to the industrial personal computer. The laser emitting mechanism emits excitation laser to the surface of a component, then ultrasonic waves are excited on the surface of the component, organic glass wedge blocks and ultrasonic receiving transducers are arranged on the two sides of the excitation laser, and the ultrasonic receiving transducers can improve the intensity of collected ultrasonic signals; and for some materials with relatively low ultrasonic excitation efficiency and weak ultrasonic signals, the residual stress detection accuracy can be effectively improved.

Description

Technical Field

[0001] The present application relates to the technical field of residual stress detection, and in particular to a laser ultrasonic residual stress detection device. Background Art

[0002] In mechanical processing, the generation of residual stress is inevitable. The influence of residual tensile stress in components usually shows harmful effects, such as reducing the fatigue strength of components, causing stress corrosion and brittle fracture, and reducing the dimensional accuracy of components. In engineering, people often only pay attention to the working stress, while ignoring the residual stress in the workpiece. In metal corrosion cracking accidents, residual stress often plays an important role. Therefore, it is particularly important to detect residual stress in components.

[0003] Laser ultrasound uses pulsed laser to irradiate the surface of solid materials. Due to the local high temperature generated on the irradiated area, a thermal elastic and ablation mechanism is formed, which in turn stimulates ultrasonic waves. The ultrasonic signal is then received by an ultrasonic receiving device for residual stress detection. Existing laser ultrasonic stress detection devices usually use laser interferometers to receive ultrasonic signals, and the residual stress detection accuracy is low, so further improvement is needed. Utility Model Content

[0004] In order to improve the accuracy of residual stress detection of components, the present application provides a laser ultrasonic residual stress detection device.

[0005] The present application provides a laser ultrasonic residual stress detection device that adopts the following technical solution:

[0006] A laser ultrasonic residual stress detection device comprises a machine platform, a laser emitting mechanism arranged on the machine platform to emit an excitation laser to a component surface, and a receiving mechanism for receiving ultrasonic signals. The machine platform is provided with an industrial computer. The receiving mechanism comprises an organic glass wedge block attached to the component surface and an ultrasonic receiving transducer arranged on the organic glass wedge block. The ultrasonic receiving transducer is electrically connected to the industrial computer.

[0007] By adopting the above technical solution, the laser emitting mechanism emits an excitation laser to the surface of the component, thereby exciting ultrasonic waves on the surface of the component. Organic glass wedges and ultrasonic receiving transducers are placed on both sides of the excitation laser. The use of ultrasonic receiving transducers can improve the intensity of the collected ultrasonic signals. For some materials with low ultrasonic excitation efficiency and weak ultrasonic signals, the accuracy of residual stress detection can be effectively improved.

[0008] Preferably, two plexiglass wedges are provided, and the two plexiglass wedges are symmetrically distributed along the excitation laser.

[0009] By adopting the above technical solution, two organic glass wedges are provided to detect the residual stress values ​​in two directions at the same time.

[0010] Preferably, the laser emitting mechanism includes a mechanical arm arranged on the machine platform, a detection shell arranged on the free end of the mechanical arm, and a laser emitter built into the detection shell, and a side wall of the detection shell is provided with a light outlet for emitting the excitation laser.

[0011] By adopting the above technical solution, during detection, the detection shell is moved to the required detection position by the robotic arm, the laser emitter is started, and the excitation laser is directly emitted from the light outlet to the surface of the component to be tested. The robotic arm can emit the excitation laser to different positions of the component.

[0012] Preferably, the laser emitting mechanism further comprises a laser modulator built into the detection housing for modulating the excitation laser emitted by the laser emitter.

[0013] By adopting the above technical solution and adding a laser modulator, the excitation laser emitted by the laser transmitter is modulated into a narrow-band laser ultrasonic wave of the required detection frequency. Laser ultrasonic waves of different frequencies can detect residual stress values ​​at different depths of the component.

[0014] Preferably, a shooting port is provided on a side wall of the detection housing, and a camera for shooting the irradiation position of the excitation laser is built into the detection housing.

[0015] By adopting the above technical solution, a camera is additionally provided to facilitate the staff to observe the irradiation position of the excitation laser.

[0016] Preferably, the receiving mechanism further comprises a bracket, the organic glass wedge is arranged on the bracket, and the bracket is provided with a suction cup adsorbed on the outer wall of the component to be tested.

[0017] By adopting the above technical solution, the bracket is adsorbed on the side wall or bottom wall of the component to be tested through the suction cup, so that the plexiglass wedge and the component to be tested are relatively fixed, effectively reducing the possibility of the plexiglass wedge falling and improving the convenience of fixing the plexiglass wedge.

[0018] Preferably, the bracket includes a mounting ring plate, a connecting plate fixedly connected to the outer side wall of the mounting ring plate, and a connecting rod fixed to the connecting plate, the suction cup is fixedly connected to the lower end of the connecting rod, and the plexiglass wedge is arranged on the mounting ring plate.

[0019] Preferably, the connecting plate is penetrated by a mounting hole for the connecting rod to slide through, the connecting rod is a screw rod, and the connecting rod is threadedly connected to a pair of limit nuts respectively located above and below the connecting plate, and the two limit nuts are respectively pressed against the upper end surface and the lower end surface of the connecting plate.

[0020] By adopting the above technical solution, the relative position of the limit nut and the connecting rod is adjusted by rotating the limit nut, thereby adjusting the relative position of the mounting ring plate and the suction cup according to the thickness of the plexiglass wedge, so that the detection surface of the plexiglass wedge fits against the surface of the component to be tested.

[0021] Preferably, the bracket also includes a movable ring plate coaxially rotatably connected to the lower part of the mounting ring plate, the two organic glass wedges are arranged on the movable ring plate, and the mounting ring plate is provided with a rotating component driving the movable ring plate to rotate around its own axis.

[0022] By adopting the above technical solution, the movable ring plate is driven to rotate relative to the mounting ring plate through the rotating assembly, thereby adjusting the relative position of the organic glass wedge block and the mounting ring plate to adapt to different detection conditions.

[0023] Preferably, the rotating assembly includes a transmission ring gear coaxially fixedly sleeved on the outer peripheral wall of the movable ring plate, a rotating motor fixedly connected to the mounting ring plate, and a transmission gear fixedly sleeved on the output shaft of the rotating motor, and the transmission gear is meshed with the transmission ring gear.

[0024] By adopting the above technical solution, the transmission gear is driven to rotate by the rotating motor, thereby driving the transmission gear ring and the movable ring plate to rotate together, thereby realizing the relative rotation of the movable ring plate and the installation ring plate.

[0025] In summary, the utility model has the following beneficial effects:

[0026] 1. The laser emitting mechanism emits an excitation laser to the surface of the component, thereby exciting ultrasonic waves on the surface of the component. Organic glass wedges and ultrasonic receiving transducers are placed on both sides of the excitation laser. The use of ultrasonic receiving transducers can improve the intensity of the collected ultrasonic signals. For some materials with low ultrasonic excitation efficiency and weak ultrasonic signals, the accuracy of residual stress detection can be effectively improved.

[0027] 2. Add a laser modulator to modulate the excitation laser emitted by the laser transmitter into a narrow-band laser ultrasonic wave of the required detection frequency. Laser ultrasonic waves of different frequencies can detect residual stress values ​​at different depths of components;

[0028] 3. The bracket is adsorbed on the side wall or bottom wall of the component to be tested through the suction cup, so that the plexiglass wedge and the component to be tested are relatively fixed, effectively reducing the possibility of the plexiglass wedge falling and improving the convenience of fixing the plexiglass wedge. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic diagram of the overall structure of a laser ultrasonic residual stress detection device in Example 1;

[0030] Figure 2is a schematic diagram of the internal structure of the detection housing in Example 1;

[0031] Figure 3 is a schematic diagram of the structure of the receiving mechanism in Example 1;

[0032] Figure 4 is a schematic diagram of the structure of the bracket in Example 2;

[0033] Figure 5 It is a schematic diagram of the structure of the rotating assembly in Example 2.

[0034] In the figure, 1. machine; 2. laser emitting mechanism; 21. mechanical arm; 22. detection shell; 221. light outlet; 222. shooting port; 23. laser emitter; 24. laser modulator; 25. camera; 3. receiving mechanism; 31. organic glass wedge; 32. ultrasonic receiving transducer; 33. bracket; 331. mounting ring plate; 332. connecting plate; 333. connecting rod; 334. movable ring plate; 335. limiting nut; 34. suction cup; 35. reinforcement plate; 351. light hole; 4. rotating assembly; 41. transmission gear ring; 42. rotating motor; 43. transmission gear. DETAILED DESCRIPTION

[0035] The following is combined with Figure 1-5 This application is described in further detail.

[0036] Embodiment 1:

[0037] The present application discloses a laser ultrasonic residual stress detection device, referring to Figure 1 , including a machine platform 1, a laser emitting mechanism 2 arranged on the machine platform 1 to emit an excitation laser to the surface of a component, and a receiving mechanism 3 for receiving an ultrasonic signal. The machine platform 1 is provided with an industrial computer.

[0038] Reference Figure 1 , Figure 2 The laser emitting mechanism 2 includes a mechanical arm 21 disposed on the machine platform 1, a detection housing 22 disposed at the free end of the mechanical arm 21, a laser emitter 23 built in the detection housing 22, and a laser modulator 24 built in the detection housing 22 for modulating the excitation laser emitted by the laser emitter 23. The base of the mechanical arm 21 is fixedly connected to the machine platform 1, and the detection housing 22 is fixedly connected to the free end of the mechanical arm 21. The same side wall of the detection housing 22 is provided with a shooting port 222 and a light outlet 221 for emitting the modulated excitation laser. The detection housing 22 is built with a camera 25 for photographing the excitation laser irradiation position through the shooting port 222. The camera 25 is a binocular industrial camera.

[0039] Reference Figure 3The receiving mechanism 3 includes an organic glass wedge 31 attached to the surface of the component and an ultrasonic receiving transducer 32 detachably connected to the organic glass wedge 31. The ultrasonic receiving transducer 32 is electrically connected to a data acquisition card in the industrial computer. In this embodiment, two organic glass wedges 31 are provided, and the two organic glass wedges 31 are symmetrically distributed along the excitation laser. The ultrasonic receiving transducer 32 is detachably connected to the inclined surface of the organic glass wedge 31 by screwing.

[0040] The implementation principle of a laser ultrasonic residual stress detection device in an embodiment of the present application is as follows: during detection, a plexiglass wedge 31 equipped with an ultrasonic receiving transducer 32 is placed at a position to be detected, the detection shell 22 is moved to the desired detection position by a mechanical arm 21, the laser transmitter 23 is started, and the excitation laser modulated by the laser modulator 24 is directly emitted from the light outlet 221 to the surface of the component to be detected, thereby exciting ultrasonic waves on the surface of the component. Organic glass wedges 31 and ultrasonic receiving transducers 32 are placed on both sides of the excitation laser. The use of ultrasonic receiving transducers 32 can improve the intensity of the collected ultrasonic signal. For some materials with low ultrasonic excitation efficiency and weak ultrasonic signals, the accuracy of residual stress detection can be effectively improved.

[0041] Embodiment 2:

[0042] The difference from Example 1 is that, referring to Figure 4 , Figure 5 The receiving mechanism 3 also includes a bracket 33, which includes a mounting ring plate 331, a connecting plate 332 fixedly connected to the outer side wall of the mounting ring plate 331, a connecting rod 333 fixed to the connecting plate 332, and a movable ring plate 334 coaxially connected to the lower end surface of the mounting ring plate 331. The connecting plate 332 is provided with a plurality of holes distributed around the axis of the mounting ring plate 331, and the connecting plate 332 is penetrated with a mounting hole for the connecting rod 333 to slide through. The connecting rod 333 is a screw rod, and the connecting rod 333 is threadedly connected with a pair of limit nuts 335 respectively located above and below the connecting plate 332, and the two limit nuts 335 are respectively pressed against the upper end surface and the lower end surface of the connecting plate 332, and the lower end of the connecting rod 333 is fixedly connected with a suction cup 34 adsorbed on the outer wall of the component to be tested.

[0043] Two organic glass wedges 31 are fixedly connected to the lower end surface of the movable ring plate 334. The mounting ring plate 331 is provided with a rotating assembly 4 that drives the movable ring plate 334 to rotate around its own axis. The rotating assembly 4 includes a transmission gear ring 41 coaxially fixedly sleeved on the outer peripheral wall of the movable ring plate 334, a rotating motor 42 fixedly connected to the mounting ring plate 331, and a transmission gear 43 fixedly sleeved on the output shaft of the rotating motor 42. The transmission gear 43 is meshed with the transmission gear ring 41. A reinforcing plate 35 is fixedly connected between the two organic glass wedges 31. The reinforcing plate 35 is provided with a light-through hole 351. The light-through hole 351 and the mounting ring plate 331 are coaxially arranged.

[0044] The transmission gear 43 is driven to rotate by the rotating motor 42, thereby driving the transmission ring gear 41 and the movable ring plate 334 to rotate together, thereby realizing the relative rotation of the movable ring plate 334 and the mounting ring plate 331, adjusting the relative position of the organic glass wedge block 31 and the mounting ring plate 331 to adapt to different detection conditions.

[0045] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A laser ultrasonic residual stress detection device, characterized in that: The invention comprises a machine platform (1), a laser emitting mechanism (2) arranged on the machine platform (1) for emitting an excitation laser to a component surface, and a receiving mechanism (3) for receiving an ultrasonic signal, wherein the machine platform (1) is provided with an industrial computer, the receiving mechanism (3) comprises an organic glass wedge (31) attached to the component surface and an ultrasonic receiving transducer (32) arranged on the organic glass wedge (31), and the ultrasonic receiving transducer (32) is electrically connected to the industrial computer; two organic glass wedges (31) are provided, and the two organic glass wedges (31) are symmetrically distributed along the excitation laser; the receiving mechanism (3) further comprises a bracket (33), the organic glass wedge (31) is provided on the bracket (33), and the bracket (33) is provided with a suction cup (34) adsorbed on the outer wall of the component to be measured.

2. The laser ultrasonic residual stress detection device according to claim 1, characterized in that: The laser emitting mechanism (2) comprises a mechanical arm (21) arranged on the machine platform (1), a detection housing (22) arranged at the free end of the mechanical arm (21), and a laser emitter (23) built into the detection housing (22); a side wall of the detection housing (22) is provided with a light outlet (221) for emitting an excitation laser.

3. The laser ultrasonic residual stress detection device according to claim 2, characterized in that: The laser emitting mechanism (2) further comprises a laser modulator (24) which is built into the detection housing (22) and is used to modulate the excitation laser emitted by the laser emitter (23).

4. The laser ultrasonic residual stress detection device according to claim 2, characterized in that: A shooting port (222) is provided on the side wall of the detection housing (22), and a camera (25) for shooting the irradiation position of the excitation laser is built into the detection housing (22).

5. The laser ultrasonic residual stress detection device according to claim 1, characterized in that: The bracket (33) comprises a mounting ring plate (331), a connecting plate (332) fixedly connected to the outer side wall of the mounting ring plate (331), and a connecting rod (333) fixed to the connecting plate (332); the suction cup (34) is fixedly connected to the lower end of the connecting rod (333); and the organic glass wedge (31) is arranged on the mounting ring plate (331).

6. The laser ultrasonic residual stress detection device according to claim 5, characterized in that: The connecting plate (332) is provided with a mounting hole through which the connecting rod (333) is slidably inserted. The connecting rod (333) is a screw rod. The connecting rod (333) is threadedly connected to a pair of limit nuts (335) respectively located above and below the connecting plate (332). The two limit nuts (335) are respectively pressed against the upper end surface and the lower end surface of the connecting plate (332).

7. The laser ultrasonic residual stress detection device according to claim 5, characterized in that: The bracket (33) further comprises a movable ring plate (334) coaxially rotatably connected to the lower part of the mounting ring plate (331), the two organic glass wedges (31) are arranged on the movable ring plate (334), and the mounting ring plate (331) is provided with a rotating assembly (4) for driving the movable ring plate (334) to rotate around its own axis.

8. The laser ultrasonic residual stress detection device according to claim 7, characterized in that: The rotating assembly (4) comprises a transmission gear ring (41) coaxially fixedly sleeved on the outer peripheral wall of the movable ring plate (334), a rotating motor (42) fixedly connected to the mounting ring plate (331), and a transmission gear (43) fixedly sleeved on the output shaft of the rotating motor (42), wherein the transmission gear (43) meshes with the transmission gear ring (41).

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