A composite device for precise powder thickness detection and ultrasonic flattening

Abstract

A composite device for precision powder thickness measurement and ultrasonic leveling is disclosed. This invention relates to the field of laser cladding technology. The device includes a worktable base with an ultrasonic thickness measuring mechanism, a flexible clamp, and an ultrasonic leveling mechanism mounted on its upper surface. The flexible clamp is located between the ultrasonic thickness measuring mechanism and the ultrasonic leveling mechanism for clamping and horizontally adjusting the workpiece to be measured. A central control module is mounted on the upper surface of the worktable base, located outside the ultrasonic leveling mechanism. The central control module is connected to both the ultrasonic thickness measuring mechanism and the ultrasonic leveling mechanism via data transmission channels, and controls the ultrasonic thickness measuring mechanism and the ultrasonic leveling mechanism to collaboratively complete the powder layer thickness measurement and leveling operations. This invention integrates ultrasonic thickness measurement and ultrasonic leveling functions to achieve real-time powder layer thickness detection and synchronous precise leveling, providing a high-quality powder layer with uniform thickness and a smooth surface for subsequent processes.

Description

Technical Field

[0001] This invention relates to the field of laser cladding technology, specifically to a composite device for achieving precision powder thickness detection and ultrasonic leveling. Background Technology

[0002] Laser cladding technology, as a highly efficient surface modification and reinforcement manufacturing technique, uses a laser beam to fuse cladding powder with the surface of a substrate to form a metallurgical bond layer. This significantly improves the wear resistance, corrosion resistance, and high-temperature resistance of the substrate and has been widely applied in key fields such as machinery manufacturing, aerospace, and mold repair. In the laser cladding process, the thickness accuracy and surface flatness of the powder layer before cladding are the core prerequisites for determining the quality of the cladding layer. A uniform and flat powder layer ensures consistent laser energy absorption, avoiding defects such as uneven cladding layer thickness, high porosity, and weak metallurgical bonding. Precise powder thickness detection is the key guarantee for achieving accurate control of the cladding layer dimensions.

[0003] Currently, the powder processing steps preceding laser cladding (thickness detection and leveling) mostly employ separate operations or simple equipment, which presents several technical limitations: First, the powder spreading and thickness measurement processes are independent of each other. Typically, powder is spread using traditional methods such as scrapers and rollers, followed by thickness measurement using contact thickness gauges or laser rangefinders. If thickness deviations or surface unevenness are found after measurement, secondary powder spreading correction is required, which not only prolongs the processing cycle but also easily disturbs the powder layer structure, leading to powder agglomeration or localized accumulation. Second, traditional powder spreading equipment has poor adaptability to ultrafine powders and low-flowability powders (such as ceramic composite powders and high-activity alloy powders). These powders, due to strong interparticle forces and insufficient flowability, are prone to forming particles during the spreading process. The powder layer may form clumps, depressions, or protrusions, making it difficult to achieve uniform dispersion using ordinary mechanical powder spreading methods. This can lead to quality problems such as cracks and inclusions in the subsequent cladding layer. Thirdly, the thickness measurement lacks a real-time feedback and adjustment mechanism. Most existing thickness measurement technologies are offline and cannot capture thickness deviations in real time during powder spreading and adjust the leveling parameters simultaneously. This results in large fluctuations in powder layer thickness (the error usually exceeds ±15μm), making it difficult to meet the requirements of high-precision cladding for powder layer thickness tolerance (within ±5μm). Fourthly, some integration attempts have not fully incorporated powder characteristics into the optimized design. Either the leveling method still relies on mechanical contact, which can damage the powder layer, or the coordination between thickness measurement and leveling is poor, making it unsuitable for powder processing requirements on complex substrate surfaces.

[0004] Furthermore, the efficiency requirements for pre-treatment powder processing in laser cladding processes are increasingly demanding. The cumbersome process connections and low production efficiency caused by separate operations have become significant bottlenecks restricting the large-scale application of laser cladding technology. Therefore, developing a pre-treatment device that can adapt to ultrafine, low-flowability powders and achieve real-time powder thickness detection and synchronous leveling is crucial. This device would address the shortcomings of existing technologies, such as low precision, poor adaptability, and insufficient efficiency, providing a high-quality powder pretreatment foundation for subsequent laser cladding processes. This is of significant practical importance for promoting the development of laser cladding technology towards higher precision and efficiency. Summary of the Invention

[0005] This invention addresses the technical problems in existing laser cladding pre-processing powder treatment, such as low efficiency caused by the separation of powder spreading and thickness measurement, uneven spreading of ultrafine powder and low-flowability powder, insufficient thickness control accuracy, and easy disturbance of powder layer. It proposes a composite device for achieving precise powder thickness detection and ultrasonic leveling.

[0006] The technical solution adopted by the present invention to solve the above problems is as follows: This invention proposes a composite device for precision powder thickness measurement and ultrasonic leveling, comprising a worktable base. An ultrasonic thickness measuring mechanism, a flexible clamp, and an ultrasonic leveling mechanism are disposed on the upper surface of the worktable base. The flexible clamp is located between the ultrasonic thickness measuring mechanism and the ultrasonic leveling mechanism for clamping and horizontally adjusting the workpiece to be measured. A central control module is installed on the upper surface of the worktable base, located outside the ultrasonic leveling mechanism. The central control module is connected to both the ultrasonic thickness measuring mechanism and the ultrasonic leveling mechanism via data transmission channels, and is used to control the ultrasonic thickness measuring mechanism and the ultrasonic leveling mechanism to collaboratively complete the powder layer thickness measurement and leveling operations.

[0007] Furthermore, the ultrasonic thickness measurement mechanism includes a high-frequency ultrasonic probe, a sound velocity calibration module, and a probe mounting base. The probe mounting base is connected to the workbench base via a mechanism support; the sound velocity calibration module is mounted on the upper surface of the probe mounting base, the high-frequency ultrasonic probe is fixed to the side wall of the sound velocity calibration module, the detection end face of the high-frequency ultrasonic probe is parallel to the substrate surface, and its ultrasonic emission direction is perpendicular to the substrate surface.

[0008] Furthermore, the high-frequency ultrasonic probe extends and retracts at its detection end by driving a miniature ball screw via a first drive motor.

[0009] Furthermore, the ultrasonic leveling mechanism includes an electric guide rail, an electric slider, a height adjustment mechanism, an ultrasonic generator, a leveling execution plate, a rotary table, an amplitude transformer, and a piezoelectric transducer. The lower end of the height adjustment mechanism is mounted on the base of the worktable via a support, and the upper end is fixed to one end of the electric guide rail. The electric slider is slidably connected to the electric guide rail, and the upper surface of the rotary table is connected to the electric slider and moves linearly back and forth along the length of the guide rail. The piezoelectric transducer is mounted on the lower surface of the rotary table. The leveling execution plate is connected to the piezoelectric transducer via the amplitude transformer. The ultrasonic generator is mounted on the support of the ultrasonic leveling mechanism.

[0010] Furthermore, the flexible fixture includes two flexible pin assemblies, two synchronous drive mechanisms, and two fixture sliding guide rails; the two fixture sliding guide rails are mounted side by side on the worktable base, the two synchronous drive mechanisms are arranged opposite each other and slidably connected to the fixture sliding guide rails, and move towards or away from each other along the length direction of the fixture sliding guide rails; each synchronous drive mechanism has a flexible pin assembly on the side facing the workpiece.

[0011] Furthermore, the flexible pin assembly includes multiple flexible pins arranged in an array. Each flexible pin is installed in a corresponding guide hole within the synchronous drive mechanism and coaxially engages with a hydraulic bushing within the guide hole. The hydraulic bushing has an annular oil chamber inside, which is connected to the hydraulic control module via an integrated oil circuit. The bottom end of each flexible pin is connected to a micro actuator via a return spring, and the micro actuator is mounted on the base plate of the synchronous drive mechanism.

[0012] Furthermore, the two synchronous drive mechanisms move in opposite directions or backwards along the length of the fixture sliding guide rail via ball screws. The ball screws are arranged parallel between the two sliding guide rails and located at the lower part of the flexible pin assembly. The two ends of the ball screws are respectively provided with threaded portions with opposite directions of rotation. They are threadedly connected to the two synchronous drive mechanisms respectively. The output end of the second drive motor is connected to one end of the ball screw through a coupling. The second drive motor drives the ball screw to rotate, thereby driving the two synchronous drive mechanisms to perform synchronous reverse linear motion.

[0013] Furthermore, the flexible fixture also includes a laser rangefinder, which is installed at the lower end of the rotary table and can move with the rotary table.

[0014] The beneficial effects of this invention are: 1. This invention integrates ultrasonic thickness measurement and ultrasonic leveling functions to achieve real-time detection of powder layer thickness and synchronous precise leveling in one operation. This avoids efficiency loss and powder disturbance caused by process separation, and provides a high-quality powder layer with uniform thickness and flat surface for subsequent processes, thereby improving the metallurgical bonding quality and dimensional accuracy of the cladding layer. 2. This invention uses flexible fixtures to clamp and level workpieces, which are compatible with workpieces of various specifications and can be adapted to complex curved surfaces. It avoids deformation and damage caused by rigid clamping and reduces the cost of fixture customization and production preparation cycle. 3. The ultrasonic probe of the ultrasonic thickness measuring mechanism of the present invention is extendable to precisely control the detection gap and reduce powder interference; the height of the probe mounting base is finely adjustable to adapt to different pre-laid powder thickness requirements. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the ultrasonic thickness measuring mechanism of the present invention; Figure 3 This is a schematic diagram of the flexible clamp of the present invention; Figure 4 This is a schematic diagram of the ultrasonic leveling mechanism of the present invention; Figure 5 This is a schematic diagram of the structure of the rotary table of the present invention; Figure 6 This is a schematic diagram of the flexible pin assembly of the present invention.

[0016] In the diagram: 1-Flexible pin, 2-Electric guide rail, 3-First drive motor; 4-Electric slider, 5-Synchronous drive mechanism, 6-High-frequency ultrasonic probe, 7-Sound velocity calibration module, 8-Second drive motor, 9-Probe mounting base, 10-Workbench base, 11-Central control module, 12-Data transmission pipeline, 13-Height adjustment mechanism, 14-Ultrasonic generator, 15-Hydraulic control module, 16-Sliding guide rail, 20-Base, 21-Leveling execution plate, 22-Rotating workbench, 23-Amplitude rod, 24-Laser rangefinder, 25-Piezoelectric transducer, 26-Ball screw, 27-Reset spring, 28-Miniature actuator, 29-Base plate, 30-Annular oil chamber, 31-Hydraulic bushing. Detailed Implementation

[0017] This embodiment proposes a composite device for precision powder thickness detection and ultrasonic leveling, such as... Figure 1As shown, the device includes a workbench base 10, which serves as the mounting base for the entire device and is a rectangular plate. The upper surface of the workbench base 10 is equipped with an ultrasonic thickness measuring mechanism, a flexible clamp, and an ultrasonic leveling mechanism. The flexible clamp is located between the ultrasonic thickness measuring mechanism and the ultrasonic leveling mechanism for clamping and horizontally adjusting the workpiece to be measured. A central control module 11 is installed on the upper surface of the workbench base 10, located outside the ultrasonic leveling mechanism. The central control module 11 is connected to the bases 20 of both the ultrasonic thickness measuring mechanism and the ultrasonic leveling mechanism via a data transmission pipe 12, and is used to control the ultrasonic thickness measuring mechanism and the ultrasonic leveling mechanism to collaboratively complete the powder layer thickness measurement and leveling operations.

[0018] like Figure 2 As shown, the ultrasonic thickness measurement mechanism includes a high-frequency ultrasonic probe 6, a sound velocity calibration module 7, and a probe mounting base 9. The probe mounting base 9 is connected to the worktable base 10 via a mechanism support 20. The sound velocity calibration module 7 is mounted on the upper surface of the probe mounting base 9, and the high-frequency ultrasonic probe 6 is fixed to the side wall of the sound velocity calibration module 7. The detection end face of the high-frequency ultrasonic probe 6 is parallel to and opposite to the substrate surface, and its ultrasonic emission direction is perpendicular to the substrate surface. In actual operation, the propagation speed of ultrasonic waves in the powder layer is dynamically matched to eliminate the influence of sound velocity fluctuations on thickness measurement.

[0019] Preferably, the high-frequency ultrasonic probe 6 is driven by a miniature ball screw via a first drive motor 3 to extend and retract the probe end of the high-frequency ultrasonic probe 6, thereby precisely controlling the detection gap and reducing powder interference. Specifically, the first drive motor 3 is fixedly mounted on the probe mounting base 9, and its output end is connected to the end of the miniature ball screw via a coupling. A sliding sleeve with a threaded connection is fitted on the miniature ball screw, and one end of the sliding sleeve is fixed to the tail of the high-frequency ultrasonic probe 6. When the motor is started, the miniature ball screw rotates to drive the sliding sleeve and the high-frequency ultrasonic probe 6 connected to it to extend and retract along its axial direction, thereby controlling the gap between the detection end face of the high-frequency ultrasonic probe 6 and the surface of the powder layer.

[0020] Preferably, the height of the probe mounting base 9 is finely adjustable to accommodate different pre-laid powder thickness requirements.

[0021] like Figure 4 , Figure 5As shown, the ultrasonic leveling mechanism includes an electric guide rail 2, an electric slider 4, a height adjustment mechanism 13, an ultrasonic generator 14, a leveling execution plate 21, a rotary table 22, an amplitude transformer 23, and a piezoelectric transducer 25. The lower end of the height adjustment mechanism 13 is mounted on the worktable base 10 via a support 20, and the upper end is fixed to one end of the electric guide rail 2. The electric slider 4 is slidably connected to the electric guide rail 2. The upper surface of the rotary table 22 is connected to the electric slider 4 and moves linearly back and forth along the length of the guide rail 2. The piezoelectric transducer 25 is mounted on the lower surface of the rotary table. The leveling execution plate 21 is connected to the piezoelectric transducer 25 via two amplitude transformers 23. The ultrasonic generator 14 is mounted on the support 20 of the ultrasonic leveling mechanism.

[0022] Preferably, there are two amplitude transformers 23. The amplitude transformer 23 is a rod-shaped structure with a cross section that gradually changes along the axial direction. Its large cross section end is connected to the piezoelectric transducer 25, and its small cross section end is connected to the leveling execution plate 21. The mechanical amplification of vibration amplitude and energy focusing are achieved by changing the cross section, thereby improving the leveling efficiency.

[0023] Preferably, the height of the height adjustment mechanism 13 is adjustable to precisely control the non-contact gap and avoid energy consumption or powder disturbance.

[0024] like Figure 1 , Figure 3 and Figure 6 As shown, the flexible fixture includes two flexible pin assemblies, two synchronous drive mechanisms 5, and two fixture sliding guide rails 16; the two fixture sliding guide rails 16 are mounted side by side on the worktable base 10 (along the width direction of the worktable base 10), the two synchronous drive mechanisms 5 are arranged opposite to each other and are slidably connected to the fixture sliding guide rails 16, and move towards or away from each other along the length direction of the sliding guide rails 16; each synchronous drive mechanism 5 has a flexible pin assembly on the side facing the workpiece.

[0025] The flexible pin assembly includes multiple flexible pins 1 arranged in an array. Each flexible pin 1 is installed in a corresponding guide hole within the synchronous drive mechanism 5 (its end extends out of the guide hole towards the workpiece to be tested) and coaxially engages with a hydraulic bushing 31 within the guide hole. The hydraulic bushing 31 has an annular oil chamber 30 inside, which is connected to a hydraulic control module 15 (including a pump, valve, and pressure sensor) via an integrated oil circuit. The hydraulic control module 15 is used to control the oil pressure to press or release the flexible pin 1. The bottom end of each flexible pin 1 is connected to a micro actuator 28 via a return spring 27, and the micro actuator 28 is mounted on the base plate 29 of the synchronous drive mechanism 5.

[0026] The two synchronous drive mechanisms 5 move in opposite directions or backwards along the length of the sliding guide rail 16 via ball screws 26. The ball screws 26 are arranged parallel between the two sliding guide rails 16 and located at the lower part of the flexible pin assembly. The two ends of the ball screws 26 are respectively provided with external threads with opposite directions of rotation and are threadedly connected to the two synchronous drive mechanisms 5. The output end of the second drive motor 8 is connected to one end of the ball screw 26 through a coupling. The second drive motor 8 drives the ball screw 26 to rotate, thereby driving the two synchronous drive mechanisms 5 to perform synchronous reverse linear motion.

[0027] The flexible fixture also includes a laser rangefinder 24, which is installed at the lower end of the rotary table 22 and can move with the rotary table 22. It is used to scan the surface of the powder layer to measure the distance and assist in the horizontal adjustment of the workpiece.

[0028] The specific workflow of this invention is as follows: Step 1: After the substrate is simply powdered, the second drive motor 8 drives the ball screw 26 to fix the substrate with the flexible pin of the flexible clamp. Step 2: The central control module 11 issues an instruction, and the height adjustment mechanism 13 and the rotating worktable 22 complete the calibration of the laser rangefinder 24. The laser rangefinder 24 scans the powder layer surface with a laser non-contact scan to measure the vertical distance between each point and the reference surface of the worktable. The overall level of the workpiece is judged by the "distance distribution trend". Step 3: The laser rangefinder 24 sends a real-time feedback signal to the central control module 11. The central control module 11 generates a corresponding signal and transmits it to the synchronous drive mechanism 5. The synchronous drive mechanism 5 uses the micro actuator 28 to fine-tune the flexible pin 1 to make the workpiece horizontal. Step 4: The central control module 11 receives the feedback signal and sends an instruction to the hydraulic control module 15 to adjust the pressure so that the hydraulic bushing 31 presses against the flexible pin 1 to complete the locking. Step 5: Input key process parameters through the human-machine interface of the central control module 11 and generate the corresponding program; Step 6: Adjust the height of the probe mounting base 9, and after the sound velocity calibration module 7 receives the signal from the central control module 11, it automatically calls the corresponding reference sound velocity and completes the probe calibration. Step 7: The central control module 11 issues a start command, and the high-frequency ultrasonic probe 6 continuously emits ultrasonic pulses. After the pulses penetrate the air gap and the powder layer, they are reflected by the substrate surface. After the reflected signal is filtered by the signal processing unit to remove noise, the data calculation unit combines the precise sound velocity of the sound velocity calibration module 7 and calculates the powder layer thickness at the current detection point using the formula "thickness = (sound velocity × round trip time) / 2", and transmits it to the central control module 11 in real time. Step 8: The central control module 11 issues a command to the height adjustment mechanism 13 to finely adjust the height of the leveling execution plate 21, ensuring that the leveling execution plate 21 maintains a uniform gap with the substrate surface. The module then outputs an adjustment command to the ultrasonic generator 14. The ultrasonic generator 14 receives the adjustment command and outputs a high-frequency electrical signal of the corresponding frequency. Step 9: The piezoelectric transducer 25 converts the electrical signal into mechanical vibration. The amplitude transformer 23 amplifies the vibration amplitude through the variable cross-section structure and focuses the energy to be directionally transmitted to the leveling execution plate 21 along the Z-axis (perpendicular to the substrate). Step 10: The leveling execution plate 21 maintains a preset non-contact gap with the powder layer. Energy is transmitted to the powder layer through high-frequency micro-vibration, breaking the van der Waals force and electrostatic force between powder particles, so that the powder presents a "quasi-fluid state", automatically filling depressions and flattening protrusions to form a uniform powder layer.

[0029] This invention, through its integrated and real-time feedback design, achieves high-precision thickness detection and high-quality ultrasonic leveling of the powder layer, providing a reliable powder pretreatment basis for laser cladding. It has good practical value and promising prospects for promotion.

[0030] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent substitutions, and improvements made to the above embodiments without departing from the scope of the present invention, based on the technical essence of the present invention and within the spirit and principles of the present invention, shall still fall within the protection scope of the present invention.

Claims

1. A device for implementing precision powder thickness detection and ultrasonic flattening, characterized in that: The device includes a workbench base (10), and the upper surface of the workbench base (10) is provided with an ultrasonic thickness measuring mechanism, a flexible clamp and an ultrasonic leveling mechanism; the flexible clamp is located between the ultrasonic thickness measuring mechanism and the ultrasonic leveling mechanism, and is used to clamp and level the workpiece to be measured; the central control module (11) is installed on the upper surface of the workbench base (10), located outside the ultrasonic leveling mechanism; the central control module (11) is connected to the ultrasonic thickness measuring mechanism and the ultrasonic leveling mechanism respectively through a data transmission pipe (12), and is used to control the ultrasonic thickness measuring mechanism and the ultrasonic leveling mechanism to work together to complete the powder layer thickness measurement and leveling operation.

2. The device according to claim 1, wherein: The ultrasonic thickness measurement mechanism includes a high-frequency ultrasonic probe (6), a sound velocity calibration module (7), and a probe mounting base (9). The probe mounting base (9) is connected to the workbench base (10) via the base (20); the sound velocity calibration module (7) is mounted on the upper surface of the probe mounting base (9); the high-frequency ultrasonic probe (6) is fixed on the side wall of the sound velocity calibration module (7); the detection end face of the high-frequency ultrasonic probe (6) is parallel to the substrate surface, and its ultrasonic emission direction is perpendicular to the substrate surface.

3. The device according to claim 2, wherein, The high-frequency ultrasonic probe (6) is driven by a miniature ball screw via a first drive motor (3) to extend and retract the probe end of the high-frequency ultrasonic probe (6).

4. The device according to claim 1, wherein, The ultrasonic leveling mechanism includes an electric guide rail (2), an electric slider (4), a height adjustment mechanism (13), a sound wave generator (14), a leveling execution plate (21), a rotary table (22), an amplitude transformer (23), and a piezoelectric transducer (25). The lower end of the height adjustment mechanism (13) is mounted on the worktable base (10) via a base (20), and the upper end is fixed to one end of the electric guide rail (2). The electric slider (4) is slidably connected to the electric guide rail (2). The upper surface of the rotary table (22) is connected to the electric slider (4), and the rotary table (22) moves linearly back and forth along the length of the guide rail (2). The piezoelectric transducer (25) is mounted on the lower surface of the rotary table (22). The leveling execution plate (21) is connected to the piezoelectric transducer (25) via the amplitude transformer (23). The sound wave generator (14) is mounted on the support (20) of the ultrasonic leveling mechanism.

5. The device according to claim 1, wherein, The flexible fixture includes two flexible pin assemblies, two synchronous drive mechanisms (5) and two fixture sliding guide rails (16); the two fixture sliding guide rails (16) are mounted side by side on the workbench base (10), the two synchronous drive mechanisms (5) are arranged opposite to each other and are slidably connected to the fixture sliding guide rails (16), and move towards or away from each other along the length of the fixture sliding guide rails (16); each synchronous drive mechanism (5) has a flexible pin assembly on the side facing the workpiece to be measured.

6. The device according to claim 1, wherein, The flexible pin assembly includes multiple flexible pins (1), which are arranged in an array. Each flexible pin (1) is installed in a corresponding guide hole in the synchronous drive mechanism (5) and coaxially cooperates with the hydraulic bushing (31) in the guide hole. The hydraulic bushing (31) has an annular oil cavity (30) inside, which is connected to the hydraulic control module (15) through an integrated oil circuit. The bottom end of each flexible pin (1) is connected to a micro actuator (28) through a reset spring (27). The micro actuator (28) is installed on the base plate (29) of the synchronous drive mechanism (5).

7. The device according to claim 1, wherein, The two synchronous drive mechanisms (5) move in opposite directions or backwards along the length of the fixture sliding guide (16) via ball screws (26). The ball screws (26) are arranged parallel between the two sliding guides (16) and located at the lower part of the flexible pin assembly. The two ends of the ball screws (26) are respectively provided with threaded portions with opposite directions of rotation. The two synchronous drive mechanisms (5) are connected by threads respectively. The output end of the second drive motor (8) is connected to one end of the ball screw (26) through a coupling. The ball screw (26) is driven to rotate by the second drive motor (8), thereby driving the two synchronous drive mechanisms (5) to perform synchronous reverse linear motion.

8. The device according to claim 1, wherein, The flexible fixture also includes a laser rangefinder (24), which is mounted on the lower end of the rotary table (22).

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