A device and method for monitoring process anomalies in cold spraying in-situ repair based on recycled dust concentration ratio

Abstract

This invention discloses an anomaly monitoring device and method for in-situ cold spraying repair process based on the recovered dust concentration ratio. It includes an extraction unit and a monitoring module. The extraction unit comprises an extraction pipeline and an extraction pump. The inlet of the extraction pump is connected to the outlet of the extraction pipeline to draw undeposited powder, rebound powder, and escaped dust from the surface of the workpiece to be repaired into the extraction pipeline, thereby transforming free dust into a stable dust flow. The monitoring module monitors and acquires in real time the dust jet signal entering the surface of the workpiece to be repaired and the dust recovery flow signal S2 entering the extraction pipeline, and continuously calculates the ratio K = S2 / S1 and the absolute changes of S1 and S2 and the fluctuation amplitude of K. The beneficial effects of this invention are: this anomaly monitoring device and method for in-situ cold spraying repair process based on the recovered dust concentration ratio can determine in real time problems such as abnormal powder feeding, abnormal decrease in deposition efficiency, and instability in the spraying process, and can distinguish between powder supply-side anomalies and deposition-side anomalies.

Description

Technical Field

[0001] This invention relates to the field of aviation maintenance technology, and in particular to an anomaly monitoring device and method for in-situ repair of cold spraying based on the concentration ratio of recycled dust. Background Technology

[0002] Cold spray in-situ repair is being gradually adopted in scenarios such as aircraft casings, flange edges, local defects in skin, fastener seats, and the inner walls of narrow cavities. Unlike large-scale fixed-point spraying under factory conditions, on-site repair in aircraft hangars is usually affected by factors such as space constraints, attitude restrictions, complex curved surfaces, fluctuating extraction conditions, and narrow operating windows. The stability of the spraying process is more sensitive to the final repair quality. Therefore, the industry has put forward increasingly higher requirements for the monitoring of the cold spraying process.

[0003] Currently, the quality control methods for cold spraying and similar thermal spraying processes mainly rely on five approaches: operator experience judgment, final inspection after spraying, particle parameter measurement under laboratory conditions, jet optical monitoring, and recovery of undeposited powder and dust protection.

[0004] The operator's experience-based judgment method, which involves the operator judging the appearance of the coating by visual inspection, judging the sound of powder delivery by hearing, and observing the visibility of the spray, is the most widely used method in on-site maintenance. However, this method is biased towards subjective judgment and requires a high level of operator experience.

[0005] The final inspection method after spraying, which uses ultrasonic, eddy current, penetrant, metallographic or bonding strength peel testing methods to judge the quality of the repair layer after spraying, is biased towards post-event verification and does not have real-time capability when an abnormality occurs. Although ultrasonic, eddy current, penetrant, metallographic and other methods after spraying can be used for final quality judgment, they can only detect problems after spraying is completed and cannot stop spraying in time when an abnormality occurs. This can easily lead to the scrapping of the entire repair layer and rework of the entire process.

[0006] The method of measuring particle parameters under laboratory conditions, which involves using particle velocimetry and imaging instruments such as DPV, CPS, and PIV to measure particle velocity, temperature, and feed rate, is mainly used in process calibration and R&D stages. However, the equipment is complex and difficult to adapt to hangar environments.

[0007] The jet optical monitoring method, which uses a transmission photoelectric pair, a light-shielding curtain, a laser scattering or backscattering probe near the nozzle exit to measure the powder concentration, transmittance or shading rate in the free jet, is used to indirectly characterize the powder feeding stability and jet density changes. It is currently the online monitoring method that is closest to the real-time quality of the spraying process. This method places the sensor in the open free jet area, and the signal is significantly affected by the reflection of the workpiece surface, local backflow, ambient light, changes in spray distance and reflection of the narrow space wall. Under the same working conditions, the signal fluctuates greatly, and the baseline drifts with the spraying posture, making it difficult to form a stable and usable process judgment. There is a problem of poor stability of free jet optical monitoring. In addition, if only the absolute dust concentration or transmittance signal is collected at a certain location, although the overall anomaly can be detected, it cannot distinguish between the two completely different process anomalies: "sudden increase in powder feeding" and "normal powder feeding but decreased deposition efficiency". The former originates from the powder supply system, while the latter originates from the spray distance, posture, surface condition or local backflow. The corresponding handling actions are completely different, and there is a problem that single-point absolute concentration monitoring cannot distinguish different sources of anomalies.

[0008] The method of undeposited powder recovery and dust protection involves removing undeposited rebound powder and escaped dust during the spraying process through exhaust hoods, dust collection hoods, or negative pressure channels. Its main purpose is powder recovery, environmental cleaning, and worker protection. It has been widely used in industrial cold spraying lines, but the collected dust recovery information is basically not used for process quality assessment.

[0009] Therefore, there is an urgent need to design an abnormal monitoring device and method for the in-situ repair process of cold spraying based on the concentration ratio of recycled dust, which can determine in real time problems such as abnormal powder feeding, abnormal decrease in deposition efficiency and unstable spraying process, and can also distinguish between abnormalities on the powder supply side and abnormalities on the deposition side. Summary of the Invention

[0010] The purpose of this invention is to overcome the above-mentioned technical deficiencies and propose an abnormal monitoring device and method for in-situ repair process of cold spraying based on the concentration ratio of recycled dust. This solves the problems in the prior art that it is impossible to determine abnormalities in powder feeding, abnormal decrease in deposition efficiency, and instability in the spraying process in real time, and it is also impossible to distinguish between abnormalities on the powder supply side and abnormalities on the deposition side.

[0011] To achieve the above technical objectives, the present invention provides an anomaly monitoring device for in-situ cold spraying repair process based on the concentration ratio of recycled dust, comprising: An air extraction unit includes an air extraction pipeline and an air extraction pump. The inlet end of the air extraction pump is connected to the outlet end of the air extraction pipeline, used to draw undeposited powder, rebound powder, and escaped dust from the surface of the workpiece to be repaired into the air extraction pipeline, so as to transform free dust into a stable dust flow; and The monitoring module is used to monitor and acquire the dust jet stream signal S1 entering the surface of the workpiece to be repaired and the dust recovery stream signal S2 entering the exhaust pipe in real time, and continuously calculate the ratio K = S2 / S1 and calculate the absolute changes of S1 and S2 and the fluctuation amplitude of K.

[0012] Furthermore, the cross-sectional area of ​​the exhaust pipe is the same at all points.

[0013] Furthermore, the air extraction pipeline is a straight pipe.

[0014] Furthermore, the predetermined location of the air extraction pipe is made of a transparent material to allow light to pass through.

[0015] Furthermore, the extraction unit also includes an extraction hood, which is fitted onto the outer wall of the cold spray nozzle and has an opening facing the surface of the workpiece to be repaired. The inlet end of the extraction pipeline is connected to the extraction hood.

[0016] Furthermore, the distance between the opening side of the extraction hood and the surface of the workpiece to be repaired is 5-20mm.

[0017] Furthermore, the monitoring module includes a first monitor, a second monitor, and a processor. The first monitor is located at the outlet end of the cold spray nozzle or inside the extraction hood to monitor the dust jet stream signal S1 entering the workpiece surface to be repaired in real time. The second monitor is located at a preset position in the extraction pipeline to monitor the dust recovery stream signal S2 entering the extraction pipeline in real time. The processor is electrically connected to the first monitor and the second monitor to acquire the dust jet stream signal S1 monitored by the first monitor and the dust recovery stream signal S2 monitored by the second monitor in real time, and continuously calculate the ratio K = S2 / S1 and simultaneously calculate the absolute changes of S1 and S2 and the fluctuation amplitude of K.

[0018] Furthermore, both the first and second monitors are transmission photoelectric pairs, reflection photoelectric probes, or backscatter dust probes.

[0019] Furthermore, the monitoring module also includes a display, which is electrically connected to the processor to display data information and abnormal signals.

[0020] On the other hand, the present invention also provides an anomaly monitoring method for in-situ cold spraying repair process based on the concentration ratio of recycled dust, applicable to the above-mentioned anomaly monitoring device for in-situ cold spraying repair process based on the concentration ratio of recycled dust, comprising the following steps: The monitoring module monitors and acquires the dust jet stream signal S1` entering the workpiece surface to be repaired under normal cold spraying conditions and the dust recovery stream signal S2` entering the extraction pipeline. The monitoring module calculates the ratio K` = S2` / S1`, and sets the allowable fluctuation range of S1`, S2` and K`; The air pump draws undeposited powder, rebound powder, and escaped dust from the surface of the workpiece to be repaired into the air extraction pipeline. The monitoring module monitors and acquires in real time the dust jet stream signal S1 entering the surface of the workpiece to be repaired and the dust recovery stream signal S2 entering the exhaust pipe. The monitoring module continuously calculates the ratio K = S2 / S1 and simultaneously calculates the absolute changes of S1 and S2 and the fluctuation amplitude of K; When S1 is outside the allowable fluctuation range of S1', S2 is simultaneously outside the allowable fluctuation range of S2', and K is within the allowable fluctuation range of K', then the powder supply is abnormal. When S1 is within the allowable fluctuation range of S1', S2 is significantly greater than S2' and K is significantly greater than K', the deposition efficiency decreases abnormally. When the instantaneous fluctuation amplitude of K increases significantly, the spraying process becomes unstable.

[0021] Compared with the prior art, the beneficial effects of the present invention include: During use, the monitoring module monitors and acquires the dust jet stream signal S1` entering the workpiece surface to be repaired under normal cold spraying conditions and the dust recovery stream signal S2` entering the extraction pipeline, and calculates the ratio K` = S2` / S1`. It sets the allowable fluctuation ranges for S1`, S2`, and K`. Then, the extraction pump draws undeposited powder, rebound powder, and escaped dust from the workpiece surface to be repaired into the extraction pipeline. The monitoring module monitors and acquires the dust jet stream signal S1 entering the workpiece surface to be repaired and the dust recovery stream signal S2 entering the extraction pipeline in real time. The monitoring module then continuously calculates the ratio K = S2 / S1 and synchronously calculates... Calculate the absolute changes of S1 and S2 and the fluctuation amplitude of K. If S1 is outside the allowable fluctuation range of S1', S2 is simultaneously outside the allowable fluctuation range of S2', and K is within the allowable fluctuation range of K', then the powder supply is abnormal. If S1 is within the allowable fluctuation range of S1', S2 is significantly greater than S2', and K is significantly greater than K', then the deposition efficiency is abnormally reduced. If the instantaneous fluctuation amplitude of K increases significantly, then the spraying process is unstable. This cold spraying in-situ repair process abnormal monitoring device and method based on the recovered dust concentration ratio can determine the problems of powder supply abnormality, abnormal decrease in deposition efficiency, and unstable spraying process in real time, and can also distinguish between powder supply side abnormality and deposition side abnormality. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of an abnormal monitoring device for in-situ repair process of cold spraying based on the concentration ratio of recycled dust provided by the present invention; Figure 2This is a schematic diagram of an abnormal monitoring method for in-situ repair process of cold spraying based on the concentration ratio of recycled dust, provided by the present invention. In the diagram: 1 - cold spray nozzle, 2 - workpiece surface to be repaired, 100 - air extraction unit, 110 - air extraction pipeline, 120 - air extraction pump, 130 - air extraction hood, 200 - monitoring module, 210 - first monitor, 220 - second monitor. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0024] This invention provides an anomaly monitoring device for in-situ repair processes using cold spraying based on the concentration ratio of recycled dust, the structure of which is as follows: Figure 1 As shown, the system includes an extraction unit 100 and a monitoring module 200. The extraction unit 100 includes an extraction pipeline 110 and an extraction pump 120. The inlet end of the extraction pump 120 is connected to the outlet end of the extraction pipeline 110 to extract undeposited powder, rebound powder, and escaped dust from the surface 2 of the workpiece to be repaired into the extraction pipeline 110, so that the free dust is transformed into a stable dust flow. The monitoring module 200 is used to monitor and acquire the dust jet flow signal S1 entering the surface 2 of the workpiece to be repaired and the dust recovery flow signal S2 entering the extraction pipeline 110 in real time, and continuously calculate the ratio K = S2 / S1 and calculate and monitor the absolute changes of S1 and S2 and the fluctuation amplitude of K.

[0025] When the cold spraying process is stable, there is a relatively stable proportional relationship between the amount of powder entering the repair zone per unit time, the amount of powder successfully deposited on the workpiece surface, and the amount of undeposited powder carried away by the recovery system. For the same part, the same material, the same nozzle, the same spray distance, and similar spatial geometry, the correspondence between the dust jet stream signal S1 entering the workpiece surface to be repaired 2 and the dust recovery stream signal S2 entering the extraction pipe 110 should be maintained within a repeatable normal window. During use, the monitoring module 200 monitors and acquires the dust jet stream signal S1' entering the workpiece surface to be repaired 2 and the dust recovery stream signal S2' entering the extraction pipe 110 under normal cold spraying conditions, and calculates the ratio K' = S2' / S1', sets the allowable fluctuation range of S1', S2', and K', and then the extraction pump 120 draws the undeposited powder, rebound powder, and escaped dust from the workpiece surface to be repaired 2 into the extraction pipe 110, through... The monitoring module 200 monitors and acquires the dust jet signal S1 entering the workpiece surface 2 to be repaired and the dust recovery signal S2 entering the exhaust pipe 110 in real time. The monitoring module 200 continuously calculates the ratio K = S2 / S1 and simultaneously calculates the absolute changes of S1 and S2 and the fluctuation amplitude of K. If S1 is outside the allowable fluctuation range of S1', S2 is simultaneously outside the allowable fluctuation range of S2', and K is within the allowable fluctuation range of K', then the powder supply is abnormal. If S1 is within the allowable fluctuation range of S1', S2 is significantly greater than S2', and K is significantly greater than K', then the deposition efficiency is abnormally reduced. If the instantaneous fluctuation amplitude of K increases significantly, then the spraying process is unstable. This cold spraying in-situ repair process abnormal monitoring device and method based on the recovery dust concentration ratio can determine the problems of abnormal powder supply, abnormal decrease in deposition efficiency, and unstable spraying process in real time, and can also distinguish between abnormalities on the powder supply side and abnormalities on the deposition side.

[0026] As a preferred embodiment, please refer to Figure 1 The cross-sectional area of ​​the exhaust pipe 110 is the same at all points, which is used to stably transport and recover the dust flow.

[0027] As a preferred embodiment, please refer to Figure 1 The exhaust pipe 110 is a straight pipe used to stably transport and recover dust streams.

[0028] In another embodiment, the exhaust pipe 110 may also be a bend. When the exhaust pipe 110 is a bend, the included angle at the bend is greater than or equal to 150° and less than 180°, so as to facilitate stable transport of the recovered dust stream.

[0029] In a preferred embodiment, the air extraction pipe 110 is made of a transparent material at a predetermined position to allow light to pass through.

[0030] In another embodiment, a detection port is provided at a preset position of the air extraction pipe 110, and a transparent sealing plate is provided at the detection port to allow light to pass through.

[0031] As a preferred embodiment, please refer to Figure 1 The extraction unit 100 also includes an extraction hood 130, which is fitted onto the outer wall of the cold spray nozzle 1 and has an opening facing the workpiece surface 2 to be repaired. The inlet end of the extraction pipe 110 is connected to the extraction hood 130. Its function is to form a semi-enclosed trapping space in the local repair area, reducing the disorderly diffusion of dust in free space. This invention does not directly perform absolute concentration inversion in the free jet, but instead uses the local extraction hood 130 to convert the unstable dust cloud in free space into a recovered dust flow transported in a fixed flow channel. Then, the ratio K of S2 / S1 is used as a simple, direct, and stable process anomaly characterization quantity, thereby significantly reducing the influence of spatial backflow, curved surface reflection, and ambient light fluctuations on the signal.

[0032] In a preferred embodiment, the distance between the opening side of the extraction hood 130 and the workpiece surface 2 to be repaired is 5-20mm, thereby forming a semi-enclosed local space in the spraying area.

[0033] As a preferred embodiment, please refer to Figure 1The monitoring module 200 includes a first monitor 210, a second monitor 220, and a processor (not shown in the figure). The first monitor 210 is located at the outlet end of the cold spray nozzle 1 or inside the extraction hood 130 to monitor the dust jet signal S1 entering the workpiece surface 2 to be repaired in real time. The second monitor 220 is located at a preset position in the extraction pipe 110 to monitor the dust recovery flow signal S2 entering the extraction pipe 110 in real time. The processor is electrically connected to the first monitor 210 and the second monitor 220 to acquire the data from the first monitor 210 in real time. The processor continuously calculates the ratio K = S2 / S1 and simultaneously calculates the absolute changes of S1 and S2 and the fluctuation amplitude of K. During operation, the first monitor 210 monitors the dust jet stream signal S1' entering the workpiece surface 2 to be repaired under normal cold spraying conditions, and the second monitor 220 monitors the dust recovery stream signal S2' entering the extraction pipe 110 under normal cold spraying conditions. The dust jet signal S1` on surface 2 and the dust recovery signal S2` entering the extraction pipe 110 under normal cold spraying conditions are monitored by the second monitor 220. The ratio K` = S2` / S1` is calculated, and the allowable fluctuation range of S1`, S2` and K` is set. Then, the extraction pump 120 draws the undeposited powder, rebound powder and escaped dust from the surface 2 to be repaired into the extraction pipe 110. The dust jet signal S1 entering the surface 2 to be repaired is monitored in real time by the first monitor 210, and the dust entering the extraction pipe is monitored in real time by the second monitor 220. The dust recovery flow signal S2 of the 110 circuit is then continuously calculated by the processor, along with the ratio K = S2 / S1 and the absolute changes of S1 and S2 and the fluctuation amplitude of K. If S1 is outside the allowable fluctuation range of S1', S2 is simultaneously outside the allowable fluctuation range of S2', and K is within the allowable fluctuation range of K', then the powder supply is abnormal. If S1 is within the allowable fluctuation range of S1', S2 is significantly greater than S2', and K is significantly greater than K', then the deposition efficiency is abnormally reduced. If the instantaneous fluctuation amplitude of K increases significantly, then the spraying process is unstable.

[0034] In a preferred embodiment, the cross-section of the extraction line 110 near the measurement area of ​​the second monitor 220 is the same.

[0035] In a preferred embodiment, the second sensor 220 can be attached to the outer wall of the exhaust pipe 110 or embedded inside the exhaust pipe 110 to avoid dust accumulation on the inner wall of the exhaust pipe 110, which could lead to optical errors.

[0036] In a preferred embodiment, both the first monitor 210 and the second monitor 220 are transmission photoelectric pairs, reflection photoelectric probes, or backscatter dust probes.

[0037] In a preferred embodiment, the monitoring module 200 further includes a display (not shown in the figure), which is electrically connected to the processor to display data information and abnormal signals.

[0038] This invention also provides a method for monitoring anomalies in the in-situ repair process of cold spraying based on the concentration ratio of recycled dust, applicable to the aforementioned device for monitoring anomalies in the in-situ repair process of cold spraying based on the concentration ratio of recycled dust, comprising the following steps: The first monitor 210 monitors the dust jet stream signal S1` entering the workpiece surface 2 to be repaired under normal cold spraying conditions, and the second monitor 220 monitors the dust recovery stream signal S2` entering the exhaust pipe 110 under normal cold spraying conditions. The processor acquires the dust jet signal S1` from the first monitor 210, which monitors the dust jet stream entering the workpiece surface 2 to be repaired under normal cold spraying conditions, and the dust recovery stream signal S2` from the second monitor 220, which monitors the dust recovery stream entering the extraction pipe 110 under normal cold spraying conditions. The processor calculates the ratio K` = S2` / S1`, and sets the allowable fluctuation range of S1`, S2` and K`; The vacuum pump 120 draws the undeposited powder, rebound powder and escaped dust from the surface 2 of the workpiece to be repaired into the vacuum pipe 110; The first monitor 210 monitors the dust jet stream signal S1 entering the workpiece surface 2 to be repaired in real time, and the second monitor 220 monitors the dust recovery stream signal S2 entering the exhaust pipe 110 in real time. The processor acquires the dust jet stream signal S1 monitored by the first monitor 210 and the dust recovery stream signal S2 monitored by the second monitor 220 in real time. The processor continuously calculates the ratio K = S2 / S1 and simultaneously calculates the absolute changes of S1 and S2 and the fluctuation amplitude of K; The monitor displays data information and abnormal signals; When S1 is significantly greater than S1', S2 is simultaneously significantly greater than S2', and K is within the allowable fluctuation range of K', then the powder supply increases; When S1 is significantly smaller than S1', S2 is simultaneously significantly smaller than S2', and K is within the allowable fluctuation range of K', the powder supply is reduced. When S1 is within the allowable fluctuation range of S1', S2 is significantly greater than S2' and K is significantly greater than K', the deposition efficiency decreases abnormally. When the instantaneous fluctuation amplitude of K increases significantly, the spraying process becomes unstable.

[0039] In the first embodiment, the abnormal monitoring device and method for in-situ repair of cold spraying based on the concentration ratio of recycled dust are applied to the monitoring of the cold spray repair process in the narrow cavity of the casing. When repairing the local corrosion area of ​​the aircraft casing in situ, the exhaust hood 130 is installed outside the nozzle, and an approximately 8mm collection gap is formed between the hood and the workpiece. The exhaust pump 120 keeps the exhaust pipeline 110 at a stable flow rate. The first monitor 210 is set at the nozzle inlet and adopts a backscattering dust probe. The second monitor 220 adopts a fixed optical path transmission photoelectric pair. Under normal working conditions, a K' window is pre-established. If S1 remains basically unchanged while K continues to be high during the spraying process, it indicates a decrease in deposition efficiency or enhanced local backflow. The operator can pause and check the spray distance, attitude or nozzle status accordingly.

[0040] In the second embodiment, the cold spray in-situ repair process abnormal monitoring device and method based on the concentration ratio of recycled dust is applied to the monitoring of the local repair process of flange edge. For areas such as flange edge that are prone to generating rebound powder, the exhaust hood 130 is a narrow slit type and the length of the exhaust pipe 110 is relatively short. Since the geometry of flange edge is more sensitive to jet rebound, the K value window can be established separately and is not shared with flat areas.

[0041] This device and method for monitoring anomalies in the in-situ repair process of cold spraying based on the ratio of recovered dust concentration is applicable to in-situ repair of cold spraying, especially suitable for working conditions where the stability of powder jet has a significant impact on quality. It is applicable to space-constrained locations such as aircraft hangars, maintenance workshops, narrow cavities, flange grooves, and partially obstructed areas. It is also applicable to anomalies such as abnormal powder feeding, powder blockage, powder interruption, abnormal decrease in deposition efficiency, enhanced jet backflow, and unstable spraying process. Furthermore, it is applicable to transmissive transmittance and shading rate measurements, backscattered dust concentration measurements, or combinations thereof.

[0042] To better understand this invention, the following is combined with... Figure 1 - Figure 2 The working principle of the technical solution of the present invention will be described in detail below: In operation, the first monitor 210 monitors the dust jet signal S1' entering the workpiece surface 2 to be repaired under normal cold spraying conditions, and the second monitor 220 monitors the dust recovery signal S2' entering the extraction pipeline 110 under normal cold spraying conditions. The processor acquires the dust jet signal S1' and the dust recovery signal S2' from the first monitor 210 and the second monitor 220 respectively, calculates the ratio K' = S2' / S1', and sets the allowable fluctuation ranges for S1', S2', and K'. Then, the extraction pump 120 draws undeposited powder, rebound powder, and escaped dust from the workpiece surface 2 to be repaired into the extraction pipeline 110. The first monitor 210 monitors the dust jet signal S1' entering the workpiece surface 2 to be repaired in real time, and the second monitor 220 monitors the dust recovery signal S2' entering the extraction pipeline 110 in real time. The dust recovery flow signal S2 from the air pipeline 110 is then continuously calculated by the processor, along with the ratio K = S2 / S1 and the absolute changes of S1 and S2 and the fluctuation amplitude of K. If S1 is significantly greater than S1', S2 is simultaneously significantly greater than S2', and K is within the allowable fluctuation range of K', then the dust supply increases. If S1 is significantly less than S1', S2 is simultaneously significantly less than S2', and K is within the allowable fluctuation range of K', then the dust supply decreases. If S1 is within the allowable fluctuation range of S1', S2 is significantly greater than S2', and K is significantly greater than K', then the deposition efficiency decreases abnormally. If the instantaneous fluctuation amplitude of K increases significantly, then the spraying process is unstable. This cold spraying in-situ repair process abnormal monitoring device and method based on the dust recovery concentration ratio can determine the problems of abnormal dust supply, abnormal decrease in deposition efficiency, and unstable spraying process in real time, and can also distinguish between abnormalities on the dust supply side and abnormalities on the deposition side.

[0043] The present invention provides an anomaly monitoring device and method for in-situ repair process of cold spraying based on the concentration ratio of recycled dust, which has the following beneficial effects: (1) The device and method for monitoring abnormalities in the in-situ repair process of cold spraying based on the concentration ratio of recycled dust does not contact the surface of the workpiece, does not require additional spraying at non-repair locations, and does not perform destructive verification on the main repair area, thus meeting the constraints of the aviation maintenance site.

[0044] (2) The device and method for monitoring abnormalities in the cold spraying in-situ repair process based on the concentration ratio of recycled dust has a simple structure and can be composed of an exhaust hood 130, a first monitor 210, a second monitor 220 and a processor. It does not require complex imaging equipment and complex algorithms and is particularly suitable for cold spraying in-situ repair scenarios in narrow spaces such as the inner cavity of the casing, flange grooves, corners, and local obstruction areas.

[0045] (3) The abnormal monitoring device and method for cold spraying in-situ repair process based on the concentration ratio of recycled dust can be used as an online process monitoring means for cold spraying in-situ repair, complementing the final release test and significantly reducing the probability of rework afterward. (4) The cold spray in-situ repair process anomaly monitoring device and method based on the concentration ratio of recycled dust does not directly perform absolute concentration inversion in the free jet. Instead, it transforms the unstable dust cloud in the free space into a recycled dust flow transported in a fixed channel through the local exhaust hood 130. Then, it uses the ratio K of S2 / S1 as a simple, direct and stable process anomaly characterization quantity, thereby significantly reducing the influence of spatial backflow, curved surface reflection and ambient light fluctuation on the signal. (5) The device and method for monitoring abnormalities in the in-situ repair process of cold spraying based on the concentration ratio of recycled dust can determine in real time the problems of abnormal powder feeding, abnormal decrease in deposition efficiency and unstable spraying process, and can also distinguish between abnormalities on the powder supply side and abnormalities on the deposition side.

[0046] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. An anomaly monitoring device for in-situ repair process of cold spraying based on the concentration ratio of recycled dust, characterized in that, include: The air extraction unit includes an air extraction pipeline and an air extraction pump. The inlet end of the air extraction pump is connected to the outlet end of the air extraction pipeline, which is used to draw undeposited powder, rebound powder and escaped dust from the surface of the workpiece to be repaired into the air extraction pipeline, so as to transform free dust into a stable dust flow. and The monitoring module is used to monitor and acquire the dust jet stream signal S1 entering the surface of the workpiece to be repaired and the dust recovery stream signal S2 entering the exhaust pipe in real time, and continuously calculate the ratio K = S2 / S1 and calculate the absolute changes of S1 and S2 and the fluctuation amplitude of K.

2. The abnormal monitoring device for in-situ repair process of cold spraying based on the concentration ratio of recycled dust as described in claim 1, characterized in that, The cross-sectional area of ​​the exhaust pipe is the same at all points.

3. The abnormal monitoring device for in-situ repair process of cold spraying based on the concentration ratio of recycled dust as described in claim 1, characterized in that, The air extraction pipeline is a straight pipe.

4. The abnormal monitoring device for in-situ repair process of cold spraying based on the concentration ratio of recycled dust as described in claim 1, characterized in that, The air extraction pipe is made of transparent material at the preset location.

5. The abnormal monitoring device for in-situ repair process of cold spraying based on the concentration ratio of recycled dust as described in claim 1, characterized in that, The extraction unit also includes an extraction hood, which is fitted onto the outer wall of the cold spray nozzle and has an opening facing the surface of the workpiece to be repaired. The inlet end of the extraction pipeline is connected to the extraction hood.

6. The abnormal monitoring device for in-situ repair process of cold spraying based on the concentration ratio of recycled dust as described in claim 5, characterized in that, The distance between the opening side of the extraction hood and the surface of the workpiece to be repaired is 5-20mm.

7. The abnormal monitoring device for in-situ repair process of cold spraying based on the concentration ratio of recycled dust as described in claim 5, characterized in that, The monitoring module includes a first monitor, a second monitor, and a processor. The first monitor is located at the outlet end of the cold spray nozzle or inside the extraction hood to monitor the dust jet stream signal S1 entering the workpiece surface to be repaired in real time. The second monitor is located at a preset position in the extraction pipeline to monitor the dust recovery stream signal S2 entering the extraction pipeline in real time. The processor is electrically connected to the first monitor and the second monitor to acquire the dust jet stream signal S1 monitored by the first monitor and the dust recovery stream signal S2 monitored by the second monitor in real time, and continuously calculate the ratio K = S2 / S1 and simultaneously calculate the absolute changes of S1 and S2 and the fluctuation amplitude of K.

8. The abnormal monitoring device for in-situ repair process of cold spraying based on the concentration ratio of recycled dust as described in claim 7, characterized in that, Both the first and second monitors are transmission photoelectric pairs, reflection photoelectric probes, or backscatter dust probes.

9. The abnormal monitoring device for in-situ repair process of cold spraying based on the concentration ratio of recycled dust as described in claim 7, characterized in that, The monitoring module also includes a display, which is electrically connected to the processor and is used to display data information and abnormal signals.

10. A method for monitoring anomalies in in-situ cold spraying repair processes based on the concentration ratio of recycled dust, comprising using the monitoring device for monitoring anomalies in in-situ cold spraying repair processes based on the concentration ratio of recycled dust as described in any one of claims 1-9, characterized in that, Includes the following steps: The monitoring module monitors and acquires the dust jet stream signal S1` entering the workpiece surface to be repaired under normal cold spraying conditions and the dust recovery stream signal S2` entering the extraction pipeline. The monitoring module calculates the ratio K` = S2` / S1`, and sets the allowable fluctuation range of S1`, S2` and K`; The air pump draws undeposited powder, rebound powder, and escaped dust from the surface of the workpiece to be repaired into the air extraction pipeline. The monitoring module monitors and acquires in real time the dust jet stream signal S1 entering the surface of the workpiece to be repaired and the dust recovery stream signal S2 entering the exhaust pipe. The monitoring module continuously calculates the ratio K = S2 / S1 and simultaneously calculates the absolute changes of S1 and S2 and the fluctuation amplitude of K; When S1 is outside the allowable fluctuation range of S1', S2 is simultaneously outside the allowable fluctuation range of S2', and K is within the allowable fluctuation range of K', then the powder supply is abnormal. When S1 is within the allowable fluctuation range of S1', S2 is significantly greater than S2' and K is significantly greater than K', the deposition efficiency decreases abnormally. When the instantaneous fluctuation amplitude of K increases significantly, the spraying process becomes unstable.

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