Molten pool camera and laser wire feeding processing device

Abstract

The molten pool camera comprises a camera body, a light supplementing assembly and a reflective mirror, the light supplementing assembly is arranged on the outer side of the camera body, the reflective mirror is arranged on the propagation path of a light source emitted by the light supplementing assembly, the reflective mirror and the camera body are obliquely arranged, and the reflection light path of the reflective mirror intersects with the optical axis of the camera body. The reflector is used for refracting light of the target scene to a lens of the camera, so that the camera obtains a target image reflected by the reflector. The reflector and the camera are obliquely arranged, and the reflection light path of the reflector intersects with the optical axis of the camera, so that the camera does not need to directly face a molten pool and can be installed at a position where the camera is more convenient to place, the internal space of a small machining machine is greatly saved, the equipment layout is optimized, and the overall operation stability of the machine is guaranteed.

Description

Technical Field

[0001] This application relates to the technical field of laser wire feeding, and in particular to a molten pool camera and a laser wire feeding processing device. Background Technology

[0002] In modern industrial manufacturing, especially in processes involving high-temperature molten pools such as welding and casting, real-time monitoring of the molten pool's condition is crucial. Accurately acquiring image information of the molten pool helps to adjust process parameters promptly, ensuring product quality, improving production efficiency, and reducing scrap rates.

[0003] For small machining machines, the compact internal space presents significant challenges to the installation of traditional molten pool monitoring equipment. Due to layout limitations, it's difficult to directly aim the camera at the molten pool to obtain clear images. Forcing installation not only encroaches on the space of other components but may also affect the overall operational stability of the machine. Furthermore, the harsh environment of the molten pool, with its high temperatures and strong radiation, can severely damage cameras positioned close to it, shortening their lifespan and increasing maintenance costs. In addition, conventional supplementary lighting systems and imaging optical path designs are more prone to uneven light distribution within the confined space of small machining machines, further reducing image clarity and accuracy. These problems severely restrict the application of molten pool monitoring technology in small machining machines, necessitating a new type of molten pool camera that saves space, protects the camera, and improves image quality to meet the specific needs of high-precision molten pool monitoring in these machines. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the purpose of this application is to provide a molten pool camera and laser wire feeding processing device that is suitable for processing environments with limited space.

[0005] The above-mentioned objective of this application is achieved through the following technical solution:

[0006] A molten pool camera includes a camera, a lighting assembly, and a reflector. The lighting assembly is located outside the camera, and the reflector is located on the path of the light source emitted by the lighting assembly. The reflector is tilted relative to the camera, and the reflected light path of the reflector intersects the optical axis of the camera. The reflector is used to refract light from the target scene onto the lens of the camera, so that the camera can acquire the target image reflected by the reflector.

[0007] As a preferred embodiment of the present invention, the supplementary lighting component includes a plurality of point light sources, which are arranged in a ring array around the lens.

[0008] As a preferred embodiment of the present invention, the light emitted by each point light source is reflected by the reflector and forms an illumination range on the observation plane of the lens, and each illumination range covers the lens.

[0009] As a preferred embodiment of the present invention, the supplementary lighting component includes a plurality of light strips arranged around the lens.

[0010] As a preferred embodiment of the present invention, the supplementary lighting assembly further includes a fixing plate, which is fixedly disposed relative to the camera. A through hole is provided in the middle of the fixing plate, the camera is directly opposite the through hole, and several of the light strips are mounted on the fixing plate.

[0011] As a preferred embodiment of the present invention, the molten pool camera further includes a housing, which includes a unit housing, a connecting component, and a lens housing. The camera and the supplementary lighting component are both installed inside the unit housing. One end of the unit housing is open. The connecting component connects the unit housing and the lens housing. The lens housing has a mounting portion for installing the reflector.

[0012] As a preferred embodiment of the present invention, the housing further includes an angle adjustment device, which is connected to the lens housing and the connecting assembly to adjust the tilt angle of the mirror relative to the camera.

[0013] As a preferred embodiment of the present invention, the molten pool camera further includes a power supply and a driver board, which are connected to the supplementary lighting component, and the driver board outputs a pulse signal.

[0014] A laser wire feeding processing device includes the aforementioned molten pool camera, and also includes a laser wire feeding head and a housing, wherein both the laser wire feeding head and the molten pool camera are disposed within the housing.

[0015] As a preferred embodiment of the present invention, the camera is vertically disposed on one side of the laser wire feeding head, and the light source emitted by the supplementary lighting component is refracted by the reflector to the molten pool generated by the laser wire feeding head.

[0016] In summary, the beneficial technical effects of this application are as follows:

[0017] 1. In this application, the reflector and the camera are set at an angle, and the reflected light path of the reflector intersects with the optical axis of the camera. This design allows the camera to be installed in a more convenient position without having to be directly facing the molten pool, which greatly saves the internal space of the small processing machine, optimizes the equipment layout, and ensures the overall stability of the machine operation.

[0018] 2. Since the camera does not need to be directly facing the molten pool, but instead obtains the target image through the refraction of a reflector, this application effectively reduces the direct effects of high temperature and strong radiation on the camera, thereby protecting the camera, extending its service life, and reducing equipment maintenance costs.

[0019] 3. In this application, the supplementary lighting component is placed outside the camera, and the reflector is placed on the propagation path of the light source emitted by the supplementary lighting component. Through the reasonable reflection and guidance of the light from the supplementary lighting component by the reflector, the target scene can be illuminated more evenly. Combined with the optimized imaging optical path, the clarity of the molten pool image acquired by the camera is greatly improved, providing a more accurate and reliable basis for adjusting process parameters and meeting the special needs of high-precision molten pool monitoring for small processing machines. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the internal structure of the molten pool camera.

[0021] Figure 2 This is a schematic diagram of the molten pool camera.

[0022] Figure 3 A schematic diagram of one arrangement of the lens and lighting components.

[0023] Figure 4 A schematic diagram illustrating the effect of one arrangement of the lens and lighting components.

[0024] Figure 5 This is a schematic diagram of an alternative arrangement for the lens and lighting components.

[0025] Figure 6 This is a schematic diagram of a laser wire feeding processing device.

[0026] The following are the symbols and their meanings: 1. Camera; 2. Lens; 3. Lighting assembly; 31. Point light source; 32. Mounting plate; 33. Light strip; 4. Reflector; 5. Housing; 51. Unit housing; 52. Connecting assembly; 53. Lens housing; 6. Power supply; 7. Drive board; 8. Laser wire feeder; 9. Housing; F. Illumination range. Detailed Implementation

[0027] The present application will be further described in detail below with reference to the accompanying drawings.

[0028] like Figures 1-2 As shown, a molten pool camera is used for real-time monitoring of the molten pool state to ensure product quality. The molten pool camera includes a camera 1, a supplementary lighting component 3, and a reflector 4.

[0029] Specifically, camera 1, as the core component for image acquisition, is preferably an industrial-grade high-speed camera that operates based on the photoelectric conversion principle. Light from the molten pool area is focused by lens 2 onto the image sensor inside camera 1. Preferably, this sensor is a CMOS or CCD type, possessing high frame rate and high resolution characteristics, capable of quickly capturing dynamic changes in the molten pool. After the light signal is converted into an electrical signal by the sensor, it is digitally processed by the image processing circuit inside camera 1, ultimately outputting a clear digital image signal. Preferably, an industrial camera such as the Basler Ace series can be used, capable of stable operation in complex environments such as high temperature and strong light.

[0030] The supplementary lighting component 3 is arranged around the outside of the lens 2 of the camera 1 to provide uniform and sufficient illumination for the target scene.

[0031] In a preferred embodiment, such as Figures 3-4 As shown, the supplementary lighting assembly 3 includes multiple point light sources 31. The point light sources 31 are high-brightness LED point light sources, such as Luminus SST-90 or Cree XLamp XHP70.2, arranged in a concentric circle array centered on the lens 2 of the camera 1. Each point light source 31 is mounted on a fixed plate 32. The fixed plate 32 has through holes through which the lens 2 passes to maintain the relatively fixed position of the fixed plate 32 and the lens 2. Preferably, the fixed plate 32 is made of aluminum for heat dissipation. Multiple point light sources 31 are mounted on the fixed plate 32, such as... Figure 3 As shown, four point light sources 31 are placed on the outside of the lens 2, with the center angles of adjacent light sources spaced 90° apart, to form a continuous and seamless ring lighting structure.

[0032] like Figure 4 As shown, Figure 4 The area marked by the dashed line shows the effective illumination area, or illumination range F, formed on the observation plane facing the lens 2 after the light emitted by the point light source 31 is reflected by the reflector 4. It can be seen that the projection of the illumination range F of each point light source 31 onto the plane covers the lens 2 or at least a part of the lens 2, and the overlapping area of ​​multiple point light sources 31 covers the entire lens 2.

[0033] Furthermore, the observation plane directly facing lens 2, i.e. Figure 4 The plane shown is perpendicular to the optical axis of lens 2, and is the plane on which lens 2 takes in light. Specifically, the light emitted by each point light source 31 is designed so that its projection onto the observation plane must at least cover the orthographic projection area of ​​lens 2 on that plane, that is, the circular area centered at the intersection of the optical axis of lens 2 and the observation plane, or completely cover that area, to ensure that lens 2 can receive sufficient reflected light.

[0034] Preferably, the point light sources 31 are arranged in a ring array centered on the lens 2, and each point light source 31 is equipped with a condenser lens, such as an aspherical lens, to constrain the diverging light rays into a fan-shaped light cone with a specific angle, such as 60° to 90°. When the light is reflected by the reflector 4 to the observation plane, the light cone forms an elliptical or circular illumination area on the plane.

[0035] More specifically, such as Figure 4 As shown, the illumination areas of each point light source 31 partially overlap, and shadows can be eliminated by superimposing multiple light sources. When a dark area is generated by the reflected light formed by a point light source 31 on the surface of the molten pool due to the angle, the illumination area of ​​the adjacent light source can cover the dark area, ultimately forming uniform illumination on the imaging surface of the lens 2.

[0036] In another preferred embodiment, such as Figure 5 As shown, the supplementary lighting assembly 3 includes multiple LED strips 33 and a mounting plate 32. The LED strips 33 surround the camera 1 and are mounted on the mounting plate 32. The mounting plate 32 has through holes, with the lens 2 facing the through holes to maintain a relatively fixed position between the mounting plate 32 and the lens 2. Preferably, the supplementary lighting assembly 3 includes four flexible LED strips 33, such as OSRAM SYNIOS P2720 or CREE XLamp CXA1512 linear light sources. The length of each LED strip 33 is customized according to the diameter of the lens 2, typically 100mm to 200mm. Each strip integrates 50 to 100 SMD packaged LED chips, with wavelengths selectable as 450nm blue light or 850nm infrared light to meet the imaging requirements of high-temperature environments. The LED strips 33 are arranged around the lens 2, centered on it, and are fixed to the mounting plate 32 using high-temperature resistant silicone adhesive or metal clips. The surface of the LED strips 33 is covered with a 0.5mm thick diffuse optical film, such as 3M Vikuiti. TM The point light source 31 is transformed into a linear surface light source, which makes the emitted light diffuse evenly to the molten pool area of ​​the target scene, eliminating the local strong light spots that may be generated by the traditional point light source 31.

[0037] Specifically, the fixing plate 32 is made of a circular or polygonal metal substrate, preferably aluminum alloy 6061-T6 or stainless steel 304, with a thickness of 2mm to 3mm. A circular through-hole matching the outer diameter of the lens 2 is opened in its center, with a diameter 2mm to 3mm larger than the lens 2 body to avoid mechanical interference. The fixing plate 32 has a 10mm to 15mm wide LED strip 33 mounting area on its edge, with anti-slip textures or heat dissipation fins on the surface for fixing the LED strip 33. When the supplementary lighting component 3 is working, the continuous linear light emitted by the LED strip 33 is reflected by the reflector 4, forming a uniform annular light field on the observation plane where the molten pool is located. The linear light emission characteristics of the flexible LED strip 33, combined with the diffuser film, improve the uniformity of illumination on the molten pool surface compared to the traditional point light source 31 scheme, making it particularly suitable for high-precision detection of the molten pool edge contour. Preferably, the LED strip 33 can be Lumileds' LUXEON Flex series flexible LED strip 33.

[0038] When camera 1 is activated, the supplementary lighting assembly 3 begins operation, emitting light that is reflected by mirror 4 and projected perpendicularly onto the surface of the molten pool. Since each point light source 31 is arranged radially around lens 2, the reflected light from the molten pool area can return along the original optical path and be received by lens 2, effectively reducing glare caused by specular reflection. Simultaneously, by adjusting the driving current of each point light source 31, independent control of the illumination intensity in different areas can be achieved, further improving image contrast.

[0039] The reflector 4 is made of a high-temperature resistant, high-reflectivity optical mirror material, such as a silver-plated or aluminum-plated glass mirror. It is positioned on the propagation path of the light source emitted from the supplementary lighting assembly 3 and installed at an angle to the camera 1. By precisely setting the tilt angle of the reflector 4 so that its reflected light path intersects with the optical axis of the camera 1, the light from the target scene, i.e., the molten pool area, can be accurately refracted onto the lens 2 of the camera 1. This design cleverly solves the problem of the limited internal space of small processing machines, making it difficult to directly align the camera 1 with the molten pool.

[0040] More specifically, the reflector 4 uses a K9 optical glass substrate with a multi-layer dielectric high-reflection coating on its surface, which can withstand high-temperature environments above 500°C. Preferably, the mirror surface is tilted at an angle of 45°±5° to the optical axis of the camera 1. This angle setting ensures that the light emitted by the supplementary lighting component 3 is reflected by the mirror surface and then perpendicularly illuminates the surface of the molten pool, while the light reflected from the molten pool returns along the original path and enters the lens 2 of the camera 1 after secondary refraction by the mirror surface.

[0041] Preferably, camera 1 employs an industrial-grade high-speed digital camera, such as the Basler Ace series or Allied Vision Mako series, with a built-in CMOS or CCD image sensor. This sensor boasts a frame rate of at least 120fps and a resolution of at least 2 megapixels, enabling rapid capture of dynamic changes in the molten pool. When camera 1 is operating, light reflected from the molten pool is refracted by mirror 4 and enters lens 2, where it is focused onto the sensor's photosensitive surface. The sensor converts the light signal into an electrical signal, which is then digitally processed by an internal DSP processor, including noise reduction and gain adjustment, before outputting standard industrial image data via a GigE or Camera Link interface.

[0042] like Figure 2 As shown, the molten pool camera also includes a housing 5, which includes a unit housing 51, a connecting assembly 52, and a lens housing 53.

[0043] Specifically, the housing 51 is a hollow cylindrical or cubic structure, made of 6061-T6 aluminum alloy or 304 stainless steel, with a wall thickness of 3mm to 5mm, and features high temperature resistance and IP65 protection rating. A camera mounting cavity is formed inside the housing 51, located at the center of the housing. The camera 1 is fixed to the camera mounting cavity by shock-absorbing rubber pads or a metal flange to ensure its stable position. Thermally conductive silicone pads are attached to the inner wall of the camera mounting cavity to conduct the heat generated by the camera 1 during operation to the outer surface of the housing 51. The outer surface of the housing 51 has a heat dissipation fin structure. The bottom of the housing 51 is open, and this open structure communicates with the camera mounting cavity. The lens 2 of the camera 1 faces the open structure, and the mounting plate is also fixedly installed within the open structure at the bottom of the housing 51.

[0044] like Figure 2 As shown, the connecting assembly 52 includes multiple connecting rods, each connecting rod connecting the two ends of the camera housing 51 and the lens housing 53 respectively. During the manufacturing process, the ambient temperature may rise, and the camera housing 51 and the lens housing 53 may experience different degrees of thermal expansion. The multiple connecting rods, through a symmetrical layout, balance the thermal stress and prevent deviations in the tilt angle of the reflector 4 caused by housing deformation. Furthermore, the connecting rods are made of aluminum alloy with good thermal conductivity, and their slender structure increases the contact area with air, thus reducing the operating temperature of the camera 1 compared to a solid connecting structure.

[0045] In a preferred embodiment, the housing 5 also includes an angle adjustment device built between the mirror housing 53 and the connecting component 52, which is designed to achieve precise control of the tilt angle of the reflector 4 and ensure the stability and accuracy of the molten pool imaging.

[0046] The angle adjustment device includes a fine-tuning screw mechanism, which comprises 2 to 4 high-precision trapezoidal screws. One end of each screw is fixed to the connecting assembly 52 via a ball joint, and the other end is screwed into the corresponding threaded hole in the mirror housing 53. The operator can drive the screws to rotate via an external knob, using the threaded transmission principle to cause the mirror housing 53 to swing around the screw axis, thereby driving the reflector 4 to adjust its tilt angle.

[0047] The angle adjustment device significantly improves the environmental adaptability of the molten pool camera. In practical applications, for different models of small processing equipment, or for installation reference offsets caused by long-term equipment operation, operators can quickly correct the angle of the reflector 4 using the adjustment device to ensure that camera 1 always acquires a clear image of the molten pool. Compared with traditional fixed-angle molten pool cameras, this design greatly shortens the optical path calibration time, improves imaging accuracy, effectively reduces equipment debugging and maintenance costs, and provides a reliable guarantee for real-time monitoring of the molten pool in industrial production.

[0048] Furthermore, the inner walls of the unit housing 51 and the connecting assembly 52 are coated with a black matte coating to prevent stray light reflection from affecting the image quality. Specifically, the inner walls are the side walls of the camera 1 and the lens 2.

[0049] The mirror housing 53 has a mounting part for placing the reflector 4. Further, the mounting part is a groove. The reflector 4 is fixed in the groove by high-temperature resistant silicone or a vacuum suction cup. The reflector 4 is flush with the plane of the mirror housing 53. The side edges of the camera 1 and the camera housing 51 are flush. The angle between the mirror housing 53 and the camera housing 51 is adjusted to determine the angle between the optical axis of the camera 1 and the mirror surface of the reflector 4.

[0050] See Figure 1 As shown, the molten pool camera is also equipped with an independent power supply 6 and a driver board 7, which are used to provide stable power and pulse drive signals to the supplementary lighting component 3, so as to achieve precise lighting control.

[0051] Specifically, power supply 6 adopts an industrial-grade DC regulated power supply with an input voltage range of 9V to 36V and an adjustable output voltage of 12V or 24V. It has a rated power of 50W and features an isolation design, employing a DC-DC isolation module, such as Mornsun WRB2412S-5W, to isolate the input power supply 6 from the driver board 7 and camera 1 circuitry. This suppresses electromagnetic interference and prevents the high-frequency pulse signals from the supplementary lighting component 3 from causing noise impact on image acquisition by camera 1. Power supply 6 is encapsulated within the unit housing 51 and connected to the housing via thermally conductive silicone. Heat dissipation is achieved through the housing 5, meeting the high-temperature environment requirements of industrial sites.

[0052] Preferably, the driver board 7 is a customized PCB circuit board. When the camera 1 performs high-speed continuous shooting, the driver board 7 outputs a pulse signal of the same frequency, causing the supplementary lighting component 3 to light up instantly during the exposure of the camera 1. This ensures sufficient illumination of the molten pool area while reducing the heat generation problem of the LED during long-term operation. The rise or fall time of the pulse signal is less than or equal to 1μs. In conjunction with a high-speed switching MOSFET, such as the IRF540N, precise flicker control of the supplementary lighting component 3 is achieved, effectively suppressing motion blur and making it suitable for clear imaging of dynamic scenes such as splashing molten metal droplets in the molten pool.

[0053] For the multi-source structure of the supplementary lighting component 3, namely the multiple point light sources 31 or multiple light strips 33 mentioned above, the driver board 7 provides multiple independent driving channels, with each channel's output current adjustable from 0 to 1.5A, supporting single-channel or multi-channel synchronous or asynchronous control. For example, by adjusting the pulse duty cycle of the light sources in different areas, enhanced illumination of the edge area of ​​the molten pool can be achieved, thereby improving image contrast.

[0054] The output of power supply 6 is connected to driver board 7 via a shielded cable. Each channel of driver board 7 is connected to the supplementary lighting component 3 via high-temperature resistant wires, such as silicone insulated wires. The wire length is less than or equal to 300mm to reduce signal attenuation. Driver board 7 and camera 1 are connected via hard-wired synchronization signals or bus communication to achieve precise matching between supplementary lighting timing and image acquisition.

[0055] See Figure 6 This paper illustrates a laser wire feeding processing device, including the aforementioned molten pool camera, a laser wire feeding head 8, and a housing 9. Preferably, the housing 9 is a 316 stainless steel sheet metal shell. The laser wire feeding head 8 is fixedly installed, and the workpiece below it moves via a three-dimensional adjustment bracket. Printing is performed during the movement, so the area below the laser wire feeding head 8 is the molten pool. The light path of the supplementary light source can be directed to the area below the laser wire feeding head 8.

[0056] The light emitted by the supplementary lighting component 3 is refracted by the tilted reflector 4 and then shines on the molten pool generated by the laser wire feed head 8. The light reflected from the molten pool returns along the original optical path and is refracted again by the reflector 4 to enter the lens 2 of the camera 1, forming a supplementary lighting-reflection-imaging optical path system.

[0057] The vertical side-mounted layout of camera 1 reduces the overall size of the device by 40%, and the camera 1 can also maintain a safe distance from the molten pool. The reflector 4 in the middle effectively reduces the damage of high temperature radiation to camera 1, and can work stably for a long time in an environment where the surface temperature of the molten pool reaches 2500℃.

[0058] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A molten pool camera, characterized in that, The device includes a camera (1), a lighting component (3), and a reflector (4). The lighting component (3) is located outside the camera (1), and the reflector (4) is located on the path of the light source emitted by the lighting component (3). The reflector (4) is tilted relative to the camera (1), and the reflected light path of the reflector (4) intersects the optical axis of the camera (1). The reflector (4) is used to refract the light of the target scene to the lens (2) of the camera (1) so that the camera (1) can acquire the target image reflected by the reflector (4).

2. The molten pool camera according to claim 1, characterized in that, The supplementary lighting component (3) includes multiple point light sources (31), which are arranged in a ring array around the lens (2).

3. The molten pool camera according to claim 2, characterized in that, The light emitted by each point light source (31) is reflected by the reflector (4) and forms an illumination range (F) on the observation plane of the lens (2), and each illumination range (F) covers the lens (2).

4. The molten pool camera according to claim 1, characterized in that, The supplementary lighting component (3) includes several light strips (33) arranged around the lens (2).

5. The molten pool camera according to claim 4, characterized in that, The supplementary lighting component (3) also includes a fixing plate (32), which is fixedly disposed relative to the camera (1). A through hole is opened in the middle of the fixing plate (32), the camera (1) is facing the through hole, and several light strips (33) are installed on the fixing plate (32).

6. The molten pool camera according to claim 1, characterized in that, It also includes an outer casing (5), which includes a unit housing (51), a connecting component (52), and a lens housing (53). The camera (1) and the fill light component (3) are both installed inside the unit housing (51). One end of the unit housing (51) is open. The connecting component (52) connects the unit housing (51) and the lens housing (53). The lens housing (53) has a mounting part for mounting the reflector (4).

7. The molten pool camera according to claim 6, characterized in that, The housing (5) also includes an angle adjustment device that connects the mirror housing (53) and the connecting assembly (52) to adjust the tilt angle of the mirror (4) relative to the camera (1).

8. The molten pool camera according to claim 1, characterized in that, It also includes a power supply (6) and a driver board (7). The power supply (6) and the driver board (7) are connected to the supplementary lighting component (3). The driver board (7) outputs a pulse signal.

9. A laser wire feeding processing device, characterized in that, The molten pool camera includes any one of claims 1-8, and further includes a laser wire feed head (8) and a housing (9), wherein the laser wire feed head (8) and the molten pool camera are both disposed within the housing (9).

10. The laser wire feeding processing device according to claim 9, characterized in that, The camera (1) is vertically mounted on one side of the laser wire feeder (8), and the light source emitted by the supplementary light assembly (3) is refracted by the reflector (4) to the molten pool generated by the laser wire feeder (8).

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