Metal coating monitoring and adjusting system based on infrared imaging

Abstract

The invention relates to a metal coating monitoring and adjusting system based on infrared imaging. The metal coating monitoring and adjusting system comprises an intelligent air knife and a high-speed infrared camera arranged in front of and / or behind the intelligent air knife. The intelligent air knife comprises a plurality of independent air outlet modules, an air outlet hole is formed in one end of each air outlet module, all the air outlet modules are arranged in the direction that the air outlet holes face the inner side, and the shape of the track where the air outlet holes are located is matched with the section shape of a workpiece. The air outlet parameters of all the air outlet modules can be independently adjusted; the high-speed infrared camera is used for capturing an infrared image of the surface of the workpiece, the computer processes the image to obtain brightness distribution information, and the pre-stored brightness-coating thickness mapping relation is combined to further obtain coating thickness distribution information of the surface of the workpiece; and the computer adjusts air outlet parameters of the intelligent air knife according to the coating thickness distribution information. The technical problem that an existing workpiece coating process cannot monitor the coating thickness on line and cannot adjust air outlet parameters of different sections of an air knife is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of process online monitoring and control, and in particular to a metal coating monitoring and adjustment system based on infrared imaging. Background Art

[0002] Galvanizing refers to the coating of metals, alloys, and other materials with a zinc layer for aesthetic purposes and rust prevention. For steel substrates, the metal coating is an anodic coating, primarily used to prevent corrosion. Its corrosion protection is highly dependent on the thickness of the coating, which should typically be within a range of 20 to 80 microns. However, existing production processes struggle to ensure uniform zinc coatings. The metal substrate often corrodes first in areas with thin zinc coatings, allowing harmful factors to continuously invade these thin areas, rendering the entire pipe useless and severely reducing the service life of the galvanized parts. Furthermore, manufacturers must adhere to relevant standards to ensure a minimum coating thickness. However, due to the instability of the coating thickness, zinc consumption increases significantly, resulting in higher costs.

[0003] The existing metal galvanizing production process usually relies on experience to control the coating thickness. Take the hot-dip galvanizing pipe process as an example. Figure 1 As shown, the process is roughly divided into three stages: suction and scooping, blowing and cooling and transportation. First, the metal pipe is immersed in the zinc pool for a period of time to react and form a thin composite layer. Then, the magnetic roller and the lifting mechanism are used to lift the metal pipe out of the zinc pool. Driven by the magnetic roller, it continues to be lifted along the roller table and passes through the middle of the fixed air ring. The fixed air ring acts as an air knife (the inner side of the fixed air ring is covered with air outlet holes). It continuously sprays the surface of the steel pipe to make the zinc layer uniform and blows the excess zinc liquid into the plating pool. After cooling and transportation, the final galvanized pipe product is formed.

[0004] However, this process has the following technical problems: (1) It is impossible to monitor the zinc layer thickness online and adjust the wind pressure and wind speed of the air knife in time during the production process; (2) The entire annular air knife is a fixed structure, which includes a ring with an air outlet gap opened on the surface of the ring towards the inner ring. The air is discharged through the air outlet gap. Each part of the annular air knife has uniform air discharge, and each part or annular segment cannot be adjusted separately. This will result in a high scrap rate and even cause the entire batch of parts to be scrapped due to the mismatch of the initial production process parameters. (3) After the metal pipe comes out of the zinc liquid pool, the zinc liquid attached to the bottom edge is thicker than other parts, and the uniform air discharge of the existing annular air knife cannot be targeted at the thicker zinc liquid at the bottom. Summary of the Invention

[0005] (1) Technical issues to be resolved In view of the above disadvantages and deficiencies of the prior art, the present invention provides a metal coating monitoring and adjustment system based on infrared imaging, which solves the technical problem that in the existing workpiece coating process, the coating thickness cannot be monitored online and the air outlet speed and air pressure of different sections of the annular air knife cannot be adjusted in real time according to the coating thickness distribution.

[0006] (II) Technical Solution The present invention provides a metal coating monitoring and adjustment system based on infrared imaging, which includes: an intelligent air knife, a first group of high-speed infrared cameras arranged in front of the intelligent air knife, and / or a second group of high-speed infrared cameras arranged behind the intelligent air knife; The intelligent air knife includes a number of independent air outlet modules. One end of each air outlet module is provided with an air outlet hole. The air outlet modules are arranged in such a way that their air outlet holes face inward and the other ends face outward, so that the shape of the trajectory where the air outlet holes of each air outlet module are located matches the cross-sectional shape of the workpiece; the air outlet parameters of each air outlet module can be independently adjusted dynamically, or several adjacent air outlet modules form an air outlet section, and the air outlet parameters of this air outlet section can be independently adjusted; The first group of high-speed infrared cameras and the second group of high-speed infrared cameras are connected to a computer. The first group of high-speed infrared cameras and the second group of high-speed infrared cameras are used to capture infrared images of the workpiece surface, transmit the infrared images to the computer, and the computer performs image processing to obtain the corresponding light and dark distribution information; based on the light and dark distribution information, the computer further obtains the coating thickness distribution information of the workpiece surface in combination with the pre-stored mapping relationship between light and darkness and coating thickness; the computer adjusts the air outlet parameters of the intelligent air knife according to the coating thickness distribution information.

[0007] According to a preferred embodiment of the present invention, when the workpiece is a circular metal pipe fitting, the air outlet modules are radially spliced in such a way that their air outlet holes face the same center point to form the intelligent air knife, and the shape of the trajectory where the air outlet holes of each air outlet module are located is circular; each air outlet module is respectively provided with a high-pressure chamber. One side of the high-pressure chamber is connected to an air supply pipe, and the air outlet hole communicates with the high-pressure chamber; a piston body is arranged inside the high-pressure chamber. The piston body has a first end facing the air outlet hole and a second end opposite to the air outlet hole; a piston push rod is connected to the side of the second end opposite to the air outlet hole. The end of the piston push rod extends to the outside of the high-pressure chamber and is connected to a micro linear servo motor; under the driving action of the micro linear servo motor, the piston body moves in the high-pressure chamber to adjust the effective volume of the high-pressure chamber and thereby adjust the air outlet pressure. Since the air supply pipe continuously supplies air, when the air supply flow rate remains unchanged, the smaller the effective volume of the high-pressure chamber of the air outlet module, the greater the air outlet pressure of this air outlet module.

[0008] Furthermore, the air supply pipes connected to each air outlet module are provided with solenoid valves that are independently controlled, and the opening degree of the solenoid valves is dynamically adjusted by a computer so as to adjust the air outlet parameters (including air velocity, air pressure, and air volume) of each air outlet module from the air supply side.

[0009] According to a preferred embodiment of the present invention, the piston body is a piston body with a gradually changing cross-section, and the cross-sectional area of the piston body gradually increases from the first end to the second end. The second end of the piston body is in a tight fit with the inner wall of the high-pressure chamber; an included angle is formed between the initial velocity of the air ejected from the air outlet hole and the workpiece surface, and this included angle is greater than 0 degrees and less than 90 degrees. The piston body with a gradually changing cross-section can improve the continuity of the adjustment of the air outlet parameters of the air outlet module and avoid jump-like adjustment. Preferably, a driving mechanism can also be provided to adjust this included angle; for example, when the plating solution is thinner, this included angle can be reduced so that more air blows in a manner close to parallel to the workpiece surface. When the plating solution is thicker, this included angle can be increased so that the ejected air directly acts on the plating solution on the workpiece surface; however, when the included angle is larger, it may cause the coating to become rougher.

[0010] According to a preferred embodiment of the present invention, the piston body is a needle-shaped piston body, and the first end of the piston body is a needle tip; under the drive of the micro linear servo motor, the needle tip of the needle-shaped piston body is inserted into the air outlet hole, thereby conveniently cleaning the metal plating solution blocked in the air outlet hole without manual cleaning by workers.

[0011] According to a preferred embodiment of the present invention, a conical transition zone is formed at the part where the high-pressure chamber communicates with the air outlet hole, and the inner contour of the conical transition zone coincides with the outer contour of the needle-shaped piston body.

[0012] According to a preferred embodiment of the present invention, it further includes an annular motor base, and the annular motor base is located on the outer circle of the intelligent air knife and has a concentric positional relationship with the intelligent air knife; the micro linear servo motors are installed on the annular motor base, and each micro linear servo motor is respectively connected to a piston push rod of an air outlet module.

[0013] According to a preferred embodiment of the present invention, the first group of high-speed infrared cameras and the second group of high-speed infrared cameras each include 3 - 6 high-speed infrared cameras, and each high-speed infrared camera is arranged around the workpiece.

[0014] According to a preferred embodiment of the present invention, the first group of high-speed infrared cameras and the second group of high-speed infrared cameras collect mid-infrared rays with a wavelength of 3 - 50 μm. The sensing results of the first group of high-speed infrared cameras and the second group of high-speed infrared cameras can be mutually verified.

[0015] According to a preferred embodiment of the present invention, the coating layer is a zinc layer, a nickel layer, a copper layer, a titanium layer, or other metal or non-metal paint surfaces.

[0016] (III) Beneficial effects The technical effects of the solution of the present invention are as follows: 1. The present invention uses infrared sensing technology to detect the thickness distribution of the plating solution on the workpiece surface, and adjusts the air outlet parameters of each air outlet module of the intelligent air knife in real time according to the thickness distribution. For the parts with a higher thickness of the plating solution attached to the workpiece surface, a larger air pressure and air speed are used for blowing, and vice versa, a smaller air pressure and air speed are used for blowing, thereby improving the uniformity of the thickness distribution of the coating on the workpiece surface. The present invention solves the technical problem that in the existing workpiece coating process, the coating thickness cannot be monitored online and the air outlet speed and air pressure of different sections of the annular air knife cannot be adjusted correspondingly according to the coating thickness distribution.

[0017] 2. The method for detecting the thickness of the plating solution based on infrared sensing technology provided by the present invention is a safe and reliable non-contact detection method. It obtains the light and dark distribution information corresponding to the infrared image by computer processing according to the infrared image collected by the infrared camera, and further obtains the coating thickness distribution information on the workpiece surface by combining the pre-stored mapping relationship between light and darkness and coating thickness.

[0018] Although there are some non-contact methods for detecting thickness in the prior art, such as electromagnetic induction method, eddy current detection method, X-ray fluorescence spectrometry (XRF method), laser confocal microscopy method, etc., they are not applicable to the field of workpiece coating process. The electromagnetic induction method is applicable to magnetic materials and not applicable to non-magnetic substrates such as aluminum and copper. The eddy current detection method is affected by the conductivity and surface roughness of the substrate; the XRF method has radiation and poor safety; the laser confocal microscopy method has high requirements for the cleanliness of the sample surface and is slow, and is not applicable to the process environment of the present invention.

[0019] 3. The intelligent air knife of the present invention is composed of several air outlet modules spliced in a ring, and the air outlet parameters of each air outlet module can be independently adjusted. To solve the problem of a larger thickness of the plating solution attached to the bottom edge of the workpiece, the air outlet pressure or air outlet speed of the air outlet module at the bottom of the intelligent air knife can be adjusted to remove more plating solution, making the coating on the workpiece surface more uniform. In addition, combining the coating thickness distribution converted from the light and dark distribution of the infrared image obtained by the computer, the air outlet parameters of the air outlet modules in the corresponding sections of the corresponding intelligent air knife are adjusted accordingly to further improve the uniformity of the coating thickness. The plating solution blown off returns to the plating bath, reducing the consumption of the plating solution.

[0020] 4. When adjusting the air outlet parameters of each air outlet module, the position of the piston body in the high-pressure chamber is estimated by a micro linear servo motor, and the air outlet parameters of this air outlet module can be adjusted. Since the air supply pipeline continuously supplies air and the supplied air needs to pass through the high-pressure chamber before spraying, the larger the volume of the high-pressure chamber, the smaller the spraying air speed and pressure. In addition, by continuously approaching the air outlet hole with the tip of the needle-shaped piston body and occupying the air outlet hole, the actual air outlet cross-sectional area of the air outlet hole becomes smaller and smaller, which also serves the purpose of increasing the air outlet pressure. The tip of the needle-shaped piston body is inserted into the air outlet hole, whereby the metal plating solution blocked in the air outlet hole can be conveniently cleaned without manual cleaning by workers. Description of the Drawings

[0021] Figure 1 Schematic diagram of the galvanizing process of a steel pipe in the prior art.

[0022] Figure 2 Schematic diagram of the coating process of the workpiece of the present invention.

[0023] Figure 3 Correspondence between the infrared image on the surface of the steel pipe and the zinc layer thickness Figure 1 .

[0024] Figure 4 Correspondence between the infrared image on the surface of the steel pipe and the zinc layer thickness Figure 2 .

[0025] Figure 5 Schematic diagram of the overall structure of the intelligent air knife.

[0026] Figure 6 For the intelligent air knife along Figure 5 Schematic diagram of two air outlet modules on the vertical section along the L line in Detailed Description of the Invention

[0027] For better explaining the present invention and facilitating understanding, the present invention will be described in detail below with reference to the drawings through specific embodiments.

[0028] Embodiment 1 As Figure 1As shown in the figure, it is a schematic diagram of the plating process of the metal pipe of the present invention. This process is roughly divided into three stages: suction and fishing, blowing and leveling, and cooling and transportation. First, the steel pipe 1 is immersed in the zinc bath for a period of time for reaction and a layer of galvanized liquid is attached. Then, through the cooperation of the magnetic roller 2 (lifting and fishing out the steel pipe 1 by suction) and the lifting mechanism 3, the steel pipe 1 is lifted out of the zinc bath. Driven by the magnetic roller 2, it continues to rise along the roller path (composed of multiple magnetic rollers 2) and passes through the middle of the intelligent air knife 4. The intelligent air knife 4 sprays air at a certain speed and pressure inside, blowing the surface of the steel pipe 1 to make the zinc layer uniform and blowing the excess zinc liquid into the plating bath. Then, after cooling and transportation, the final galvanized steel pipe is formed. On one side of the roller path, there are a first group of high-speed infrared cameras 51 and a second group of high-speed infrared cameras 52. Among them, the first group of high-speed infrared cameras 51 is arranged in front of the intelligent air knife 4, and the second group of high-speed infrared cameras 52 is arranged behind the intelligent air knife 4. The first group of high-speed infrared cameras 51 and the second group of high-speed infrared cameras 52 are also connected to the computer 6. Among them, the first group of high-speed infrared cameras 51 and the second group of high-speed infrared cameras 52 respectively include 3-6 high-speed infrared cameras. Each high-speed infrared camera is arranged around the steel pipe 1 and is used to capture the infrared image of the surface of the steel pipe 1 and transmit the infrared image to the computer 6. The computer 6 performs image processing to obtain the corresponding light and dark distribution information. Based on the light and dark distribution information, the computer performs conversion processing in combination with the pre-stored mapping relationship between light and darkness and coating thickness to obtain the distribution information of the zinc layer thickness on the surface of the steel pipe 1.

[0029] In the present invention, the principle of the high-speed infrared camera for detecting the zinc layer thickness on the surface of the steel pipe 1 is as follows: Since the steel pipe 1 with the plating solution attached comes out of the plating bath in a high-temperature state, its surface emits infrared light. As the materials of the steel pipe 1 and the zinc layer on its surface are different, their infrared emissivities for emitting infrared light are also different. The steel pipe 1 is made of a steel-based material, and its infrared emissivity is greater than that of the zinc layer (see Table 1). When reflected in an infrared image (also known as a thermal image), the image of the bare steel pipe 1 is brighter, and the infrared image of zinc is darker. Similarly, when galvanizing the surface of the steel pipe 1, the thicker the thickness of the zinc layer covering, the higher the degree of "darkness" of the image. On the contrary, the thinner the thickness of the zinc layer covering, the lower the degree of "darkness" of the image, the higher the degree of "brightness", and it is also closer to the infrared image of the bare steel pipe 1. According to this rule, before the system of the present invention is officially used, infrared images of galvanized steel pipes and the corresponding zinc layer thicknesses (measuring the coating thickness by the metal corrosion method) can be pre-produced and collected. The computer processes these collected infrared images to obtain the corresponding light and dark distribution information. The light and dark can be quantitatively processed to obtain quantified light and dark data. A quantity-quantity mapping relationship is established between the light and dark data and the zinc layer thickness. Finally, a database containing a large amount of "infrared image" → light and dark distribution information → zinc layer thickness distribution information is obtained, and the database is pre-stored in the computer. During the subsequent production process application, the computer processes the infrared image transmitted back by the infrared camera and combines the database to obtain the thickness distribution information of the zinc layer on the surface of the steel pipe 1.

[0030] Table 1: Infrared Emissivities of Zinc Layer and Steel

[0031] As Figure 3 and Figure 4 shown, they are all infrared images obtained when the infrared camera of the present invention is used to photograph galvanized steel pipes in the laboratory. Under laboratory conditions, the galvanized steel pipe is heated to make its temperature uniform. Due to the higher infrared emissivity of the steel-based material, it appears bright in the image, while the emissivity of the zinc layer is lower, and the image appears dark. Infrared rays have a certain degree of penetrability. In the place where the coating is thinner, more infrared rays emitted by the steel pipe penetrate, and the image of this part is brighter. In the place where the coating is thicker, less infrared rays emitted by the steel pipe penetrate, so the image of this part is darker. In other words, the lower the infrared emissivity in the dark area, it indicates that the zinc layer in this part is thicker; the higher the infrared emissivity in the bright area, it indicates that the zinc layer in this part is thinner or the zinc layer has been damaged (the steel pipe is partially exposed). Therefore, according to the infrared image collected by the infrared camera, the thickness situation of the zinc layer at this part can be identified.

[0032] Regarding the principle of detecting the thickness of the zinc layer on the surface of the steel pipe 1 by a high-speed infrared camera, there is theoretical support. According to Planck's law and Wien's displacement law, when a metal is in a high-temperature state, it will radiate infrared rays of different wavelengths outward, and its radiation energy is proportional to the fourth power of the temperature and proportional to the emissivity of the object. Also according to the Stefan-Boltzmann law in the theory of thermal radiation, the radiant exitance ; where, is the Stefan - Boltzmann constant ; is the emissivity of the object; T is the absolute temperature (K) of the object.

[0033] It should be noted that since the infrared emissivities of the base materials and coating materials of pipe fittings made of different materials are all different, the database needs to be constructed specifically.

[0034] Common infrared light rays can be divided into near - infrared, mid - infrared and far - infrared according to the wavelength band, as follows: ① Near - infrared (0.76 - 3μm): Suitable for low - temperature measurement, with low radiation energy but high sensitivity. ② Mid - infrared (3 - 50μm): High radiation energy and strong penetration ability. ③ Far - infrared (15 - 1000μm): Suitable for high - temperature measurement, with high radiation energy but weak penetration ability. In the present invention, the first group of high - speed infrared cameras 51 and the second group of high - speed infrared cameras 52 preferably collect the mid - infrared wavelength rays on the surface of the steel pipe 1 to obtain infrared images, and the sensing results of the first group of high - speed infrared cameras 51 and the second group of high - speed infrared cameras 52 can be mutually verified. As Figure 3 shown is the mid - infrared thermal imaging of the galvanized steel pipe collected by the infrared camera in the laboratory.

[0035] Combined with Figure 1 and Figure 5 and Figure 6 shown, the intelligent air knife 4 includes a number of independent air - outlet modules 41. One end of each air - outlet module 41 is provided with an air - outlet hole 42. Each air - outlet module 41 is spliced radially with its air - outlet hole 42 facing the same center point to form the intelligent air knife 4. Finally, the trajectory of the air - outlet holes 42 of each air - outlet module 41 is a circle to match the cross - section of the steel pipe 1. Among them, the air - outlet parameters (the air - outlet parameters are mainly the air - outlet pressure or the initial velocity of the air - outlet) of each air - outlet module 41 can be independently adjusted dynamically. Specifically, the air - outlet parameters of each air - outlet module 41 are independently adjusted by the computer 6 according to the thickness distribution information of the zinc layer on the surface of the steel pipe 1 obtained.

[0036] Combined with Figure 5 and Figure 6As shown in the figure, each air outlet module 41 is respectively provided with a high-pressure chamber 40. One side of the high-pressure chamber is connected to an air supply pipe, and the air outlet holes 42 of each air outlet module 41 communicate with the high-pressure chamber 40. Inside the high-pressure chamber 40, there is a piston body 43, which has a first end facing the air outlet hole 42 and a second end opposite to the air outlet hole. One side of the second end is connected to a piston push rod 44, and the end of the piston push rod 44 extends to the outside of the high-pressure chamber 40 and is connected to a micro linear servo motor 45. Under the driving action of the micro linear servo motor 45, the piston body 43 moves in the high-pressure chamber 40 to change the effective volume of the high-pressure chamber 40. Since the air supply pipe continuously supplies air, when the air supply flow rate remains unchanged, the smaller the effective volume of the high-pressure chamber of the air outlet module 41, the greater the air outlet pressure of the air outlet module 41. Among them, the number of micro linear servo motors 45 can be equal to the number of air outlet modules 41, or several adjacent air outlet modules 41 can form an air outlet section, and this air outlet section shares a micro linear servo motor 45.

[0037] In order to install these micro linear servo motors 45, an annular motor base can be further provided on the outer ring of the intelligent air knife, and these micro linear servo motors are installed on the annular motor base.

[0038] In one embodiment, the piston body 43 is preferably a piston body with a gradually changing cross-section, and its cross-sectional area gradually increases from the first end to the second end. The second end of the piston body 43 is in a tight fit with the inner wall of the high-pressure chamber 40. The piston body with a gradually changing cross-section can make the adjustment of the effective volume of the high-pressure chamber 40 continuous, thereby making the adjustment of the air outlet parameters of the air outlet module 41 continuous and avoiding jump adjustment. As Figure 6 shown, in a more preferred embodiment of the present invention, the piston body 43 is a needle-shaped piston body, the first end of the piston body 43 is a needle tip, and a conical transition zone is formed at the part where the high-pressure chamber 40 communicates with the air outlet hole 42. The inner contour of the conical transition zone coincides with the outer contour of the needle-shaped piston body 43. Under the push of the micro linear servo motor 45, finally, the needle tip of the needle-shaped piston body 43 can be inserted into the air outlet hole 42, whereby the metal plating solution blocked in the air outlet hole 42 can be conveniently cleaned without manual cleaning by workers. An included angle is formed between the initial velocity of the air ejected from the air outlet hole 42 and the surface of the metal pipe, and this included angle is greater than 0 degrees and less than 90 degrees. Preferably, an independent driving mechanism can also be provided to adjust this included angle; for example, when the plating solution is thinner, the included angle can be reduced so that more air blows in a manner close to parallel to the surface of the metal pipe, and when the plating solution is thicker, the included angle can be increased so that the ejected air directly acts on the plating solution on the surface of the metal pipe.

[0039] Further, a solenoid valve with independent control is provided at the connection between each air outlet module 41 and the air supply pipe. The opening degree of the solenoid valve is dynamically adjusted by a computer 6 so as to adjust the air outlet parameters (including air velocity, air pressure and air volume) of each air outlet module 41 from the air supply side. The adjustment on the air supply side and the adjustment of the piston body 43 in the high-pressure chamber 40 can be jointly applied to the plating process of the metal pipe.

[0040] Embodiment 2 This embodiment only includes a set of high-speed infrared cameras, which are arranged behind the intelligent air knife 4. In the steel pipe galvanizing process, the defective parts of galvanizing (such as the damaged parts of the zinc layer) are continuous. For example, Figure 3 and Figure 4 as shown in the zinc layer accumulation (thicker part), zinc layer scratches or damaged parts may have trailing properties. Therefore, a set of high-speed infrared cameras are arranged right behind the intelligent air knife 4 for real-time detection, and the galvanizing situation can also be detected in time and the working parameters of the intelligent air knife 4 can be adjusted through the computer. In addition, the mapping relationship between the infrared image and the thickness behind the intelligent air knife 4 is clearer. Therefore, it is more accurate to detect the thickness of the zinc layer on the surface of the steel pipe 1 by arranging the high-speed infrared cameras behind the intelligent air knife 4.

[0041] Embodiment 3 Embodiment 1 is used for the steel pipe galvanizing process. Therefore, the trajectory of the air outlet holes 42 of each air outlet module 41 of the intelligent air knife 4 is a circle to match the cross-section of the steel pipe 1. In this embodiment, if it is used for the galvanized steel plate production process, the trajectory of the air outlet holes 42 of each air outlet module 41 of the intelligent air knife 4 forms a square that matches the cross-section of the steel plate, and the air outlet modules 41 surround the workpiece; if it is used for the galvanized angle steel production process, the trajectory of the air outlet holes 42 of each air outlet module 41 of the intelligent air knife 4 forms a triangle, and the air outlet modules 41 surround the workpiece.

[0042] Embodiment 4 Embodiment 1 is used for the steel pipe galvanizing process, and a database of the mapping relationship between the light and dark information distribution of the infrared image and the galvanizing thickness needs to be established in advance in the computer for real-time monitoring of the thickness distribution information of the zinc layer on the surface of the base material. In this embodiment, when the system of the present invention is used for nickel plating, copper plating, chromium plating or titanium plating of workpieces, a database of the mapping relationship between the light and dark information distribution of the infrared image and the thickness of the nickel layer, copper layer, chromium layer or titanium layer on the surface of the base material needs to be established in the computer.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements, or in the case where the technical features in the above embodiments do not conflict with each other, can be combined in the manner described in the embodiments, and these modifications, replacements or combinations do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A metal plating monitoring and adjustment system based on infrared imaging, characterized in that Comprising: An intelligent air knife, a first group of high-speed infrared cameras arranged in front of the intelligent air knife and / or a second group of high-speed infrared cameras arranged behind the intelligent air knife; The intelligent air knife includes a number of independent air outlet modules. One end of each air outlet module is provided with an air outlet hole. The air outlet modules are arranged in such a way that their air outlet holes face inwards and the other ends face outwards, so that the shape of the trajectory where the air outlet holes of each air outlet module are located matches the cross-sectional shape of the workpiece; the air outlet parameters of each air outlet module can be independently and dynamically adjusted, or several adjacent air outlet modules form an air outlet section, and the air outlet parameters of this air outlet section can be independently adjusted; The first group of high-speed infrared cameras and the second group of high-speed infrared cameras are connected to a computer. The first group of high-speed infrared cameras and the second group of high-speed infrared cameras are used to capture infrared images of the workpiece surface, transmit the infrared images to the computer, and the computer performs image processing to obtain the corresponding light and dark distribution information; based on the light and dark distribution information, the computer further obtains the coating thickness distribution information on the workpiece surface in combination with the pre-stored mapping relationship between light and dark degree - coating thickness; the computer adjusts the air outlet parameters of the intelligent air knife according to the coating thickness distribution information.

2. The metal coating monitoring and adjustment system according to claim 1, wherein When the workpiece is a circular metal pipe fitting, the air outlet modules are radially spliced in such a way that their air outlet holes face the same center point to form the intelligent air knife, and the shape of the trajectory where the air outlet holes of each air outlet module are located is circular; each air outlet module is respectively provided with a high-pressure chamber. One side of the high-pressure chamber is connected to an air supply pipe, and the air outlet hole communicates with the high-pressure chamber; a piston body is arranged inside the high-pressure chamber. The piston body has a first end facing the air outlet hole and a second end opposite to the air outlet hole; a piston push rod is connected to the side of the second end opposite to the air outlet hole. The end of the piston push rod extends outside the high-pressure chamber and is connected to a micro linear servo motor; through the driving action of the micro linear servo motor, the piston body moves in the high-pressure chamber.

3. The metal coating monitoring and adjustment system according to claim 2, wherein The air supply pipes connected to each air outlet module are provided with independently controlled solenoid valves, and the opening degree of the solenoid valves is dynamically adjusted by the computer so as to adjust the air outlet parameters of each air outlet module from the air supply side.

4. The metal coating monitoring and adjustment system according to claim 2, wherein The piston body is a piston body with a gradually changing cross-section. The cross-sectional area of the piston body gradually increases from the first end to the second end. The second end of the piston body is in a tight fit with the inner wall of the high-pressure chamber; an included angle is formed between the initial velocity of the air ejected from the air outlet hole and the workpiece surface, and this included angle is greater than 0 degrees and less than 90 degrees.

5. The metal coating monitoring and adjustment system according to claim 4, wherein The piston body is a needle-shaped piston body, and the first end of the piston body is a needle tip; under the driving of the micro linear servo motor, the needle tip of the needle-shaped piston body is inserted into the air outlet hole.

6. The metal coating monitoring and adjustment system according to claim 5, characterized in that: A conical transition zone is formed at the part where the high-pressure chamber communicates with the air outlet hole, and the inner contour of the conical transition zone coincides with the outer contour of the needle-shaped piston body.

7. The metal coating monitoring and adjustment system according to claim 2, wherein It further includes an annular motor base. The annular motor base is located on the outer circle of the intelligent air knife and has a concentric position relationship with the intelligent air knife; the micro linear servo motor is installed on the annular motor base.

8. The metal coating monitoring and adjustment system according to claim 1, wherein The first group of high-speed infrared cameras and the second group of high-speed infrared cameras each include 3-6 high-speed infrared cameras, and each high-speed infrared camera is arranged around the workpiece.

9. The metal coating monitoring and adjustment system according to claim 1, wherein The first group of high-speed infrared cameras and the second group of high-speed infrared cameras collect mid-infrared rays with a wavelength of 3-50 μm.

10. The metal coating monitoring and adjustment system according to claim 1, characterized in that: The coating is a zinc layer, a nickel layer, a copper layer, a titanium layer or a non-metallic paint surface.

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