Metal printing complex runner powder cleaning system

Abstract

The invention relates to the technical field of metal powder cleaning control, in particular to a metal printing complex runner powder cleaning system which comprises a powder cleaning machine, a powder collecting module, a powder cleaning monitoring module and a powder cleaning control module. The powder monitoring unit is used for monitoring the air inlet dust concentration and the exhaust dust concentration in the powder collecting module in real time and shooting powder cloud videos at different angles in the powder cleaning process to determine a powder cloud panoramic model; the powder cleaning control module determines the dust characterization state of the part according to the exhaust dust concentration in the first preset time so as to determine a first adjusting strategy, determines the powder cloud change trend in the powder cleaning process according to the powder cloud panoramic model so as to determine the powder cleaning state, and determines a second adjusting strategy according to the powder cleaning state in the second preset time; according to the device, efficient and accurate cleaning and intelligent regulation and control of residual powder are achieved, and the powder cleaning quality and efficiency are effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of metal powder cleaning control, and in particular to a metal printing complex flow channel powder cleaning system. Background Art

[0002] Selective Laser Melting (SLM) is an advanced metal additive manufacturing technology that builds parts with complex shapes by melting metal powder layer by layer. During the SLM process, unmelted metal powder will remain on the surface of the molded parts and in the internal holes and gaps. If these residual powders are not cleaned in time, they will affect the surface quality, dimensional accuracy, mechanical properties and subsequent processing of the parts. At present, the common powder cleaning methods mainly include manual cleaning, air blowing cleaning, vibration cleaning and chemical cleaning. Manual cleaning is inefficient and it is difficult to ensure the consistency of the cleaning effect. Air blowing cleaning is difficult to completely remove powder from the internal and hidden parts of some complex-shaped parts. Vibration cleaning may cause damage to the parts. Chemical cleaning may introduce new impurities and involve environmental issues. Therefore, an efficient, thorough and non-destructive laser selective melting post-processing powder cleaning system is needed to meet the needs of industrial production.

[0003] The prior art discloses a device for vibrating and cleaning powder in the inner cavity and finishing the inner surface of laser selective melting formed products. This device can effectively solve the current problems of manual knocking and cleaning of residual powder in the inner cavity and poor inner surface quality of laser selective melting formed wing products by using a vibration and rotation system, a powder cleaning power and recovery system, and an inner surface finishing system. It can achieve efficient and rapid cleaning of residual powder in the inner cavity of complex hollow lattice structures of wing surfaces, greatly improving the cleaning efficiency and ensuring the cleaning quality of residual powder in the inner cavity. This invention integrates an electrochemical workstation into the equipment, which can achieve electrochemical polishing of the inner surface of the wing surface and improve the surface quality of the entire inner cavity of the wing surface. It can be seen that this invention has the following problems:

[0004] This invention cleans metal powders of different machine models through fixed patterns pre-stored in the equipment, but fails to perform real-time intelligent perception and analysis of differences in structure, material, process characteristics, and powder residue conditions among different machine models, and thus fails to flexibly make adaptive adjustments to cleaning parameters, resulting in low powder cleaning efficiency for each machine model. Summary of the invention

[0005] To this end, the present invention provides a metal printing complex flow channel powder cleaning system to overcome the problem of the prior art of cleaning metal powders of different models through fixed patterns pre-stored in the equipment, but failing to perform real-time intelligent perception and analysis of the differences in structure, material, process characteristics and powder residue conditions of different models, and thus failing to flexibly make adaptive adjustments to the cleaning parameters, resulting in low powder cleaning efficiency for each model.

[0006] To achieve the above object, the present invention provides a metal printing complex flow channel powder cleaning system, comprising:

[0007] Powder purifier, used to vibrate and remove residual powder from parts and recycle it without pollution;

[0008] A powder collection module, which is connected to the powder cleaning machine and is used to collect the metal powder cleaned from the parts and perform preliminary separation of the metal powder;

[0009] A powder cleaning monitoring module, which is connected to the powder cleaning machine and the powder collecting module respectively, and includes a dust monitoring unit and a powder monitoring unit;

[0010] The dust monitoring unit is used to monitor the intake dust concentration and exhaust dust concentration at the air inlet and the exhaust port of the sealed collection box in the powder collection module in real time;

[0011] The powder monitoring unit includes a plurality of video shooting components and video reconstruction components, each of which is used to shoot powder cloud videos of the powder purifier at different angles during the powder cleaning process, and the video reconstruction component is used to determine a powder cloud panoramic model according to the powder cloud videos at different angles;

[0012] a powder cleaning control module, which is connected to the powder cleaning machine and the powder cleaning monitoring module respectively, and is used to determine the dust characterization state of the part according to the exhaust dust concentration at a first preset time to determine whether to determine a first adjustment strategy for a first powder cleaning parameter in combination with the dust concentration difference, determine a powder cloud change trend during the powder cleaning process according to the powder cloud panoramic model to determine a powder cleaning state, and determine a second adjustment strategy for a second powder cleaning parameter according to the powder cleaning state at a second preset time;

[0013] Wherein, the first powder cleaning parameter includes powder cleaning power and negative pressure power, and the second powder cleaning parameter includes powder cleaning time;

[0014] The first start time of the first preset time is the initial powder cleaning start time, and the second end time of the second preset time is the initial powder cleaning end time.

[0015] As a preferred technical solution for the metal printing complex flow channel powder cleaning system, the powder collection module includes a sealed collection box and a negative pressure generating device;

[0016] The sealed collection box is used to collect the metal powder cleaned from the parts, and a powder filtering device is arranged inside the sealed collection box to perform preliminary separation of powders of different particle sizes;

[0017] The negative pressure generating device is connected to the sealed collecting box and is used for sucking the powder in the cleaning process into the sealed collecting box by generating negative pressure.

[0018] As a preferred technical solution for the metal printing complex flow channel powder cleaning system, in the powder cleaning monitoring module, the dust monitoring unit includes two dust sensors respectively arranged at the air inlet and the exhaust port of the sealed collection box.

[0019] As a preferred technical solution for the metal printing complex flow channel powder cleaning system, the powder cleaning control module determines the dust characterization state of the part according to the exhaust dust concentration at the first preset time to determine the first adjustment strategy of the first powder cleaning parameter, or determines the first adjustment strategy of the first powder cleaning parameter in combination with the dust concentration difference, including:

[0020] If the exhaust dust concentration is greater than the concentration threshold, the dust characterization state of the part is determined to be an abnormal characterization state and a first adjustment strategy is determined according to the dust concentration difference, wherein:

[0021] If the dust concentration difference is greater than or equal to the concentration difference reference value, it is determined that the first adjustment strategy is to reduce the dust cleaning power;

[0022] If the dust concentration difference is less than the concentration difference reference value, it is determined that the first adjustment strategy is not formulated, and it is determined that the powder filtering device of the sealed collection box is faulty;

[0023] If the exhaust dust concentration is less than or equal to the concentration threshold, it is determined that the dust characterization state of the part is a normal characterization state, and it is determined not to formulate the first adjustment strategy;

[0024] The dust concentration difference is determined according to the difference between the intake dust concentration and the exhaust dust concentration.

[0025] As a preferred technical solution for the metal printing complex flow channel powder cleaning system, the powder cleaning control module determines whether to formulate the first adjustment strategy for the second time according to the dust characterization state for a preset time after reducing the powder cleaning power, including:

[0026] If the dust characterization state is still the abnormal characterization state, it is determined that the first adjustment strategy is formulated for the second time, and the first adjustment strategy formulated for the second time is to maintain the reduced powder cleaning power and reduce the negative pressure power.

[0027] As an optimal technical solution for the metal printing complex flow channel powder cleaning system, the video reconstruction component converts powder cloud videos at different angles into three-dimensional point cloud data of the powder cloud at various angles through a three-dimensional reconstruction method, and forms a powder cloud panoramic model with a spatial structure based on point cloud fusion and rendering technology.

[0028] As a preferred technical solution for the metal printing complex flow channel powder cleaning system, the powder cleaning control module determines the volume time domain diagram of the powder cloud according to the real-time panoramic model of the powder cloud, and determines the powder cloud change trend during the powder cleaning process according to the real-time fluctuation parameters of the volume time domain diagram to determine the powder cleaning state, including:

[0029] If the real-time fluctuation parameter at each moment is less than or equal to the preset fluctuation value, it is determined that the powder cloud change trend is a continuous decreasing trend, and the powder removal state is determined to be a normal state;

[0030] If the real-time fluctuation parameter at any moment is greater than the preset fluctuation value, the powder cloud change trend is determined to be a fluctuation change trend, and the powder removal state is determined to be an abnormal state.

[0031] As an optimal technical solution for the metal printing complex flow channel powder cleaning system, the powder control module determines the real-time volume difference based on the powder cloud volume at the current moment and the powder cloud volume at the previous moment, and determines the real-time fluctuation parameter based on the percentage of the real-time volume difference and the powder cloud volume at the current moment.

[0032] As a preferred technical solution of the metal printing complex flow channel powder cleaning system, the powder control module determines a second adjustment strategy for the second powder cleaning parameter according to the powder cleaning state at a second preset time, including:

[0033] If the powder cleaning state at the second preset time is an abnormal state, determining that the second adjustment strategy is to increase the powder cleaning time;

[0034] If the powder removal state at the second preset time is a normal state, it is determined that the second adjustment strategy is not formulated.

[0035] As a preferred technical solution for the metal printing complex flow channel powder cleaning system, the powder control module determines the increased powder cleaning time according to the volume ratio of the powder cloud volume at the second end time to the preset volume, wherein:

[0036] If the volume ratio is less than or equal to the preset ratio, the increased powder cleaning time is determined to be the standard time;

[0037] If the volume ratio is greater than a preset ratio, the increased powder cleaning time is determined to be the product of the standard time and the volume ratio.

[0038] Compared with the prior art, the beneficial effect of the present invention is that the metal printing complex flow channel powder cleaning system provided by the present invention realizes efficient and accurate cleaning and intelligent regulation of residual powder of metal printing complex flow channel parts through the coordinated operation of multiple modules, effectively improves the powder cleaning quality and efficiency, reduces the impact on the environment and ensures the stability of equipment operation;

[0039] In particular, the powder collection module collects and preliminarily separates metal powders of different particle sizes through a sealed collection box and an internal powder filtering device, and at the same time relies on a negative pressure generating device connected to the sealed collection box to generate negative pressure to inhale the powder, and cooperates with the dust monitoring unit to set dust sensors at the air inlet and exhaust port to achieve efficient powder collection, prevent powder from escaping and preliminarily separate powders of different particle sizes, and also facilitates monitoring of dust concentration, thereby ensuring the orderly progress of the powder cleaning process, improving the powder cleaning quality, reducing dust pollution and helping the system to operate stably;

[0040] In particular, the powder cleaning control module effectively improves the working efficiency of the powder cleaning system, ensures the powder cleaning quality and environmental compliance, and enhances the stability and safety of equipment operation through precise monitoring and intelligent regulation. Among them, the powder cleaning control module accurately determines the dust characterization state of the parts based on the comparison between the exhaust dust concentration and the concentration threshold within the first preset time and the relationship between the dust concentration difference and the concentration difference reference value, thereby determining the first adjustment strategy of the powder cleaning power. When the exhaust dust concentration is too high and the dust concentration difference meets the conditions, the powder cleaning power can be reasonably reduced to avoid excessive powder cleaning and dust escape. In the case of specific faults, it can be discovered and alarmed in time to ensure the normal operation and powder cleaning effect of the system. The module also flexibly decides whether to formulate an adjustment strategy for the second time based on the dust characterization state of the preset time after reducing the powder cleaning power. When necessary (the dust characterization state is still an abnormal characterization state), the reduced powder cleaning power is maintained and the negative pressure power is reduced to further optimize the powder cleaning process, so that the powder cleaning parameters always adapt to the actual powder cleaning needs and improve the powder cleaning efficiency and quality.

[0041] In particular, the powder cleaning control module can keep the powder cleaning process in the best state at all times by real-time monitoring and dynamic regulation of the changing trend of the powder cloud, effectively reduce powder residue, and improve the cleanliness and quality of parts; at the same time, this precise control strategy helps to reduce the energy consumption and wear of the powder cleaning equipment, extend the service life of the equipment, enhance the stability and reliability of the system operation, reduce production interruptions and cost increases caused by incomplete powder cleaning or equipment failure, and improve the overall benefits of the entire metal printing complex flow channel powder cleaning system. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 A connection diagram of a powder cleaning system for complex flow channels in metal printing according to an embodiment of the present invention;

[0043] Figure 2This is a connection diagram of a powder cleaning monitoring module according to an embodiment of the present invention;

[0044] Figure 3 A flow chart for determining a first adjustment strategy for an embodiment of the present invention;

[0045] Figure 4 The present invention is a flowchart for determining a second adjustment strategy according to an embodiment of the present invention. DETAILED DESCRIPTION

[0046] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0047] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0048] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings. This is merely for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0049] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0050] See also Figure 1 and Figure 2 As shown, they are respectively a connection diagram of a metal printing complex flow channel powder cleaning system according to an embodiment of the present invention and a connection diagram of a powder cleaning monitoring module according to an embodiment of the present invention. An embodiment of the present invention provides a metal printing complex flow channel powder cleaning system, comprising:

[0051] Powder purifier, used to vibrate and remove residual powder from parts and recycle it without pollution;

[0052] A powder collection module, which is connected to the powder cleaning machine, is used to collect the metal powder cleaned from the parts and perform preliminary separation on the metal powder to prevent the powder from escaping;

[0053] A powder cleaning monitoring module, which is connected to the powder cleaning machine and the powder collecting module respectively, and includes a dust monitoring unit and a powder monitoring unit;

[0054] The dust monitoring unit is used to monitor the intake dust concentration and exhaust dust concentration at the air inlet and the exhaust port of the sealed collection box in the powder collection module in real time;

[0055] The powder monitoring unit includes a plurality of video shooting components and video reconstruction components, each of which is used to shoot powder cloud videos of the powder purifier at different angles during the powder cleaning process, and the video reconstruction component is used to determine a powder cloud panoramic model based on the powder cloud videos at different angles to determine the spatial structure of the powder cloud;

[0056] In practice, the video shooting component is usually a high-definition motion camera, and the video shooting components are respectively arranged on the inner wall of the powder cleaning machine; at least three video shooting components are included, one video shooting component is located at the center of the inner wall at the top of the powder cleaning machine to obtain a downward-looking powder cloud video, and the other two video shooting components are evenly arranged on the inner wall on the side of the powder cleaning machine to obtain a front-view powder cloud video and a left-view powder cloud video respectively; it is also possible to increase the acquisition of a rear-view powder cloud video and a right-view powder cloud video to obtain a more accurate powder cloud panoramic model;

[0057] a powder cleaning control module, which is connected to the powder cleaning machine and the powder cleaning monitoring module respectively, and is used to determine the dust characterization state of the part according to the exhaust dust concentration at a first preset time to determine whether to determine a first adjustment strategy for a first powder cleaning parameter in combination with the dust concentration difference, determine a powder cloud change trend during the powder cleaning process according to the powder cloud panoramic model to determine a powder cleaning state, and determine a second adjustment strategy for a second powder cleaning parameter according to the powder cleaning state at a second preset time;

[0058] Among them, the first powder cleaning parameter includes powder cleaning power and negative pressure power, and the second powder cleaning parameter includes powder cleaning time; it can be understood that the powder cleaning power refers to the power intensity of the powder cleaning tool in the powder cleaning machine when it is working. If the powder cleaning tool is a brush, the powder cleaning power is the speed of the brush rotating or moving. When the brush contacts the surface of the part at a higher speed to clean the powder, the powder cleaning power is higher; conversely, the powder cleaning power is low at a low speed; if the powder cleaning tool is an ultrasonic vibration head, the powder cleaning power is reflected in the frequency of ultrasonic vibration. A higher frequency means stronger vibration energy, which can make the powder more easily detached from the surface of the part and the inside of the complex flow channel. At this time, the powder cleaning power is higher; and the powder cleaning power generated by a lower frequency is lower; the negative pressure power refers to the intensity of the negative pressure generated by the negative pressure generating device in the powder collection module. The negative pressure power can be adjusted by changing the fan speed, wherein the fan speed is in direct proportion to the negative pressure power;

[0059] The first start time of the first preset time is the initial powder cleaning start time, and the second end time of the second preset time is the initial powder cleaning end time;

[0060] It can be understood that the duration of the first preset time is usually shorter than the duration of the second preset time; the first preset time is usually from the initial powder cleaning start time to the first end time, and the second preset time is usually from the second start time to the initial powder cleaning end time; it can be understood that after placing the parts to be cleaned and selecting the powder cleaning mode, there will be a fixed powder cleaning time (from the initial powder cleaning start time to the initial powder cleaning end time) and fixed powder cleaning parameters. The powder cleaning system provided by the present invention is used to determine whether the mode is appropriate after selecting the powder cleaning mode and whether the first powder cleaning parameters and the second powder cleaning parameters need to be adjusted.

[0061] In practice, the duration of the first preset time is usually ≤3 minutes; usually, when the powder cleaning device is started and the gas in the sealed collection box starts to flow to the exhaust port, the exhaust dust concentration can be monitored. This time is very short and is almost synchronized with the powder cleaning process; therefore, only a relatively short first preset time needs to be set to determine whether to adjust the first powder cleaning parameter, but too short a time also makes the judgment too one-sided, so the duration of the first preset time is preferably set to 2 minutes;

[0062] In implementation, the duration of the second preset time is usually ≤10min. The second preset time is needed to judge the powder cleaning effect under the set powder cleaning mode. If the time is too short, the accuracy of judging the powder cleaning effect cannot be guaranteed. However, if the second preset time is too long, it may not have reached the end stage of the cleaning mode and the judgment may be inaccurate. Therefore, the duration of the second preset time is preferably set to 5min.

[0063] It can be understood that the powder cleaning monitoring module monitors the dust concentration at the air inlet and exhaust port of the sealed collection box in real time, and the powder cleaning control module determines the dust characterization state of the parts based on the exhaust dust concentration at the first preset time, and then determines the first adjustment strategy of the powder cleaning power and the negative pressure power, which can quickly respond to changes in the powder cleaning process, ensure the balance between powder cleaning effect and efficiency, and avoid excessive or insufficient powder cleaning; the powder monitoring unit uses multiple video shooting components to shoot powder cloud videos from different angles and uses the video reconstruction component to construct a panoramic model to determine the spatial structure of the powder cloud. Based on this, the powder cleaning control module can judge the powder removal status according to the powder cloud change trend, so as to evaluate the cleaning within the second preset time. The second adjustment strategy of the powder mode is used to determine the effectiveness of the powder mode and the powder cleaning time, making the powder cleaning process more targeted and adaptable; the powder collection module is connected to the powder cleaner, and preliminary separation can be performed when collecting metal powder to prevent powder overflow. Combined with the reasonable regulation of negative pressure power, it not only ensures the effective recovery of powder and reduces resource waste, but also reduces the pollution of dust emissions to the environment, which meets environmental protection requirements; through precise adjustment of powder cleaning parameters, it avoids damage to parts caused by excessive powder cleaning power and impact of improper negative pressure power on the filter device of the powder collection module, thereby extending the service life of the equipment, maintaining the overall stable operation of the system, and reducing downtime and cost increases caused by equipment failure or maintenance.

[0064] Specifically, the powder collection module includes a sealed collection box and a negative pressure generating device;

[0065] The sealed collection box is used to collect the metal powder cleaned from the parts, and a powder filtering device is arranged inside the sealed collection box to perform preliminary separation of powders of different particle sizes;

[0066] The negative pressure generating device is connected to the sealed collecting box and is used for sucking the powder in the cleaning process into the sealed collecting box by generating negative pressure.

[0067] Specifically, in the powder cleaning monitoring module, the dust monitoring unit includes two dust sensors respectively arranged at the air inlet and the air outlet of the sealed collection box.

[0068] It can be understood that the powder collection module collects and preliminarily separates metal powders of different particle sizes through a sealed collection box and an internal powder filtering device, and relies on a negative pressure generating device connected to the sealed collection box to generate negative pressure to inhale the powder, and cooperates with the dust monitoring unit to set dust sensors at the air inlet and exhaust port to achieve efficient powder collection, prevent powder overflow and preliminarily separate powders of different particle sizes, and also facilitate the monitoring of dust concentration, thereby ensuring the orderly progress of the powder cleaning process, improving the powder cleaning quality, reducing dust pollution and helping the system to operate stably.

[0069] It is understandable that the dust sensor in the present invention can be any dust sensor in the prior art, including: (1) an optical dust sensor, in which scattering occurs when light is irradiated onto dust particles. The sensor has a light source (such as a laser diode) and a photodetector inside. The light emitted by the light source is irradiated onto dust particles passing through the sensor detection area, and the scattered light is received by the photodetector. The dust concentration is calculated based on the intensity of the light scattering, wherein the more dust particles there are, the greater the intensity of the scattered light. The optical dust sensor has high sensitivity and can detect tiny dust particles. It is more effective for detecting low concentration dust at the exhaust port. It can detect dust particles with a particle size between 0.1 microns and 10 microns (which covers the particle size range of most metal powders), and the response speed of the optical dust sensor is relatively fast and can reflect the change of dust concentration in real time. (2) an electrostatic induction dust sensor, which detects dust concentration by utilizing the electrostatic induction generated by dust particles when passing through the sensor. When dust particles pass through the electric field inside the sensor, they will be charged. These charged dust particles will generate The induced charge is generated, and the dust concentration can be determined by detecting the size of the induced charge. The more dust particles there are, the more induced charge is generated. This sensor has good adaptability to dust of different particle sizes and has high accuracy. It can work in complex airflow environments and has strong anti-interference ability. At the exhaust port of the sealed collection box, the airflow speed and direction may fluctuate to a certain extent. The electrostatic induction dust sensor can still detect the dust concentration relatively stably. (3) β-ray absorption dust sensor uses the absorption characteristics of β-rays (electron rays) to measure dust concentration. It includes a β-ray source and a detector. When the β-ray passes through the airflow containing dust, part of the β-ray will be absorbed by the dust particles, and the β-ray intensity detected by the detector will be weakened. The dust concentration can be calculated based on the attenuation degree of the β-ray intensity. The β-ray absorption dust sensor is a high-precision dust concentration detection device with a wide measurement range. It can effectively detect dust from low concentration to high concentration. Its measurement results are less affected by the physical properties of the dust particles (such as color and shape). It can accurately detect the concentration of metal powders of different materials.

[0070] See also Figure 3 As shown, it is a flow chart of determining the first adjustment strategy according to an embodiment of the present invention.

[0071] Specifically, the powder cleaning control module determines the dust characterization state of the part according to the exhaust dust concentration at the first preset time to determine the first adjustment strategy of the first powder cleaning parameter, or determines the first adjustment strategy of the first powder cleaning parameter in combination with the dust concentration difference, including:

[0072] If the exhaust dust concentration is greater than the concentration threshold, the dust characterization state of the part is determined to be an abnormal characterization state and a first adjustment strategy is determined according to the dust concentration difference, wherein:

[0073] If the dust concentration difference is greater than or equal to the concentration difference reference value, it is determined that the first adjustment strategy is to reduce the powder cleaning power; it is understandable that the dust concentration at the exhaust port of the sealed collection box will be relatively high at the beginning of powder cleaning. This is because at the beginning of powder cleaning, a large amount of powder originally attached to the surface of the part is cleaned off and is quickly sucked into the sealed collection box under the action of negative pressure. At this time, the filter device in the collection box may not have time to effectively intercept all the powder, and some powder will move to the exhaust port with the airflow, resulting in an increase in the dust concentration at the exhaust port; as the powder cleaning process continues, the dust concentration will usually gradually decrease; this is because as time goes by As the dust moves, the filter device in the collection box gradually takes effect, intercepting more powder in the box; and the amount of powder remaining on the surface of the parts is also decreasing, and the amount of powder that is cleaned and enters the collection box is also decreasing, so that the dust concentration at the exhaust port shows a downward trend; however, the filter device has played a role within the first preset time, and the dust concentration difference at this time should be greater than or equal to the concentration difference reference value; therefore, when the exhaust dust concentration is greater than the concentration threshold and the dust concentration difference is greater than or equal to the concentration difference reference value, it can be determined that the first powder cleaning parameter is too large, resulting in too much powder being discharged in an instant, so the first powder cleaning parameter needs to be reduced;

[0074] If the dust concentration difference is less than the concentration difference reference value, it is determined that the first adjustment strategy is not formulated, and it is determined that the powder filter device of the sealed collection box is faulty; it is understandable that blockage or failure of the filter device of the sealed collection box will also affect the change of dust concentration. When the filter device is blocked, the flow of air in the box is blocked, which may cause some powder to not be effectively filtered, thereby increasing the dust concentration at the exhaust port; if the filter device is damaged, such as a ruptured filter element, a large amount of powder that was originally intercepted will leak to the exhaust port side, which will also cause the dust concentration to rise sharply; therefore, when the exhaust dust concentration is greater than the concentration threshold and the dust concentration difference is less than the concentration difference reference value, it is judged that the powder filter device of the sealed collection box is faulty / blocked, and an alarm signal needs to be issued and the powder filter device needs to be repaired;

[0075] Wherein, the dust concentration difference is determined according to the difference between the intake dust concentration and the exhaust dust concentration;

[0076] In implementation, the concentration difference reference value is determined according to the filtration efficiency of the cyclone separator and other filtration equipment built into the filtration device, and the concentration difference reference value is determined by the minimum filtration efficiency when it works normally, and the concentration difference reference value = minimum filtration efficiency × intake dust concentration;

[0077] In practice, the concentration threshold is determined based on environmental regulations / emission requirements / specifications for dust emissions in different industries.

[0078] In practice, the powder cleaning power after reduction = the powder cleaning power before reduction × concentration threshold ÷ exhaust dust concentration;

[0079] If the exhaust dust concentration is less than or equal to the concentration threshold, it is determined that the dust characterization state of the part is a normal characterization state, and it is determined not to formulate the first adjustment strategy.

[0080] Specifically, the powder cleaning control module determines whether to formulate the first adjustment strategy for the second time according to the dust characterization state for a preset time after reducing the powder cleaning power, including:

[0081] If the dust characterization state is still an abnormal characterization state, it is determined that the first adjustment strategy is formulated for the second time, and the first adjustment strategy formulated for the second time is to maintain the reduced cleaning power and reduce the negative pressure power; it can be understood that if the exhaust dust concentration is still greater than the concentration threshold after adjusting the cleaning power, it means that the adjustment is not enough, and it is necessary to reduce the dust entering the sealed collection box by adjusting the negative pressure power of the negative pressure generating device to achieve the effect of reducing the exhaust dust concentration;

[0082] In implementation, the negative pressure power after reduction = negative pressure power before reduction × concentration threshold ÷ exhaust dust concentration;

[0083] If the dust characterization state is a normal characterization state, it is determined that the first adjustment strategy is not formulated for a second time, and dust cleaning is performed according to the first adjustment strategy formulated for the first time.

[0084] In implementation, the preset duration is set to be equal to the duration of the first preset time, that is, after executing the first adjustment strategy, the duration of the first preset time continues to be determined, and the dust characterization state is determined according to the exhaust dust concentration during this period;

[0085] It can be understood that the exhaust dust concentration changes with time, so the exhaust dust concentration within a period of time refers to the average value of the exhaust dust concentration during this period of time.

[0086] It can be understood that the powder cleaning control module accurately determines the dust characterization state of the parts based on the comparison between the exhaust dust concentration and the concentration threshold within the first preset time and the relationship between the dust concentration difference and the concentration difference reference value, thereby determining the first adjustment strategy of the powder cleaning power. When the exhaust dust concentration is too high and the dust concentration difference meets the conditions, the powder cleaning power can be reasonably reduced to avoid excessive powder cleaning and dust overflow; in the case of specific faults, it can be discovered and alarmed in time to ensure the normal operation and powder cleaning effect of the system; the module also flexibly decides whether to formulate an adjustment strategy for the second time based on the dust characterization state for a preset time after reducing the powder cleaning power. When necessary (the dust characterization state is still an abnormal characterization state), the reduced powder cleaning power is maintained and the negative pressure power is reduced to further optimize the powder cleaning process, so that the powder cleaning parameters always adapt to the actual powder cleaning needs and improve the powder cleaning efficiency and quality.

[0087] It can be understood that the powder cleaning control module determines the reduced powder cleaning power and negative pressure power based on a scientific calculation method during the process of adjusting the powder cleaning parameters, which not only realizes the effective control of the powder cleaning effect, but also avoids excessive impact or damage to equipment such as the powder cleaning machine and powder collection module due to improper parameter adjustment, thereby extending the service life of the equipment, reducing the frequency of equipment failures and maintenance, reducing operating costs, and ensuring the long-term stable operation of the entire powder cleaning system.

[0088] Specifically, the video reconstruction component converts powder cloud videos at different angles into three-dimensional point cloud data of the powder cloud at various angles through a three-dimensional reconstruction method, and forms a powder cloud panoramic model with a spatial structure based on point cloud fusion and rendering technology.

[0089] It is understandable that the 3D reconstruction method and point cloud fusion and rendering technology are both existing technologies;

[0090] In practice, the 3D reconstruction method includes: firstly, camera calibration is performed to determine the intrinsic parameters (such as focal length, principal point position, etc.) and extrinsic parameters (such as camera position and posture) of each camera, which is the basis for subsequent 3D reconstruction; then, feature extraction algorithms (such as SI FT, SURF, etc.) are used to extract feature points in each video frame; then, corresponding feature points in video frames of different viewing angles are found through feature matching algorithms; finally, these matched feature points are used for 3D reconstruction to obtain a 3D point cloud model of the powder cloud;

[0091] The 3D point cloud data from various angles obtained by the previous 3D reconstruction methods (such as multi-view geometry or motion recovery structure) need to be fused to form a complete powder cloud model with spatial structure. Point cloud fusion technology can align and merge point clouds from different perspectives, remove duplicate points and fill possible holes. Then, the fused point cloud model is converted into a panoramic video through rendering technology, so that it can intuitively display the spatial structure of the powder cloud.

[0092] In implementation, the point cloud fusion and rendering technology includes: first, using a point cloud registration algorithm (such as the ICP algorithm-iterative closest point algorithm) to register point clouds of different perspectives to find the best alignment between them, and then merging the registered point clouds through a fusion algorithm to obtain a complete powder cloud point cloud model, and then selecting a suitable rendering engine (such as OpenGL, Unity, etc.) to render the point cloud model. During the rendering process, set parameters such as light source, viewing angle, color, etc. to generate a panoramic video of a powder cloud with a spatial structure; in specific implementation, the rendering parameters can also be adjusted according to actual needs, such as emphasizing the density changes and movement direction of the powder cloud.

[0093] See also Figure 4 As shown, it is a flow chart of determining the second adjustment strategy according to an embodiment of the present invention.

[0094] Specifically, the powder cleaning control module determines the volume time domain diagram of the powder cloud according to the real-time panoramic model of the powder cloud, and determines the powder cloud change trend during the powder cleaning process according to the real-time fluctuation parameter of the volume time domain diagram to determine the powder cleaning state, including:

[0095] If the real-time fluctuation parameter at each moment is less than or equal to the preset fluctuation value, it is determined that the powder cloud change trend is a continuous decreasing trend, and the powder removal state is determined to be a normal state;

[0096] If the real-time fluctuation parameter at any moment is greater than the preset fluctuation value, the powder cloud change trend is determined to be a fluctuation change trend, and the powder removal state is determined to be an abnormal state.

[0097] It can be understood that the abscissa of the volume time domain diagram is time, and the ordinate is the volume of the powder cloud;

[0098] In implementation, the preset fluctuation value ∈ [1%, 5%]. The smaller the preset fluctuation value is set, the more stable the determined continuous reduction trend will be. However, the amount of dust in the powder cleaning process is bound to fluctuate rather than decrease in a straight line. Therefore, the preset fluctuation value cannot be set too small, and is preferably set to 5%.

[0099] It can be understood that the powder cleaning control module constructs a volume time domain diagram of the powder cloud, and determines the powder cloud change trend and powder removal status based on the comparison between the real-time fluctuation parameters and the preset fluctuation values. When the real-time fluctuation parameters are all within a reasonable range, it can accurately determine that the powder cloud shows a continuous downward trend and the powder removal status is normal, providing a reliable basis for the smooth progress of the powder cleaning process; and when abnormal fluctuations occur, it can quickly detect and determine them as fluctuation change trends and abnormal removal status, and promptly discover potential problems in the powder cleaning process.

[0100] Specifically, the powder control module determines the real-time volume difference according to the powder cloud volume at the current moment and the powder cloud volume at the previous moment, and determines the real-time fluctuation parameter according to the percentage of the real-time volume difference to the powder cloud volume at the current moment.

[0101] It can be understood that the real-time fluctuation parameter = (powder cloud volume at the current moment - powder cloud volume at the previous moment) ÷ powder cloud volume at the current moment × 100%.

[0102] Specifically, the powder control module determines a second adjustment strategy for a second powder cleaning parameter according to the powder cleaning state at a second preset time, including:

[0103] If the powder removal state at the second preset time is abnormal, it means that the powder in the current part has not been completely removed and there is still powder remaining inside the part, that is, the part has not entered the final stage of the powder removal process, but has reached the final stage of the set powder removal mode, which means that the powder removal time is insufficient, so it is determined that the second adjustment strategy is to increase the powder removal time;

[0104] If the powder removal state at the second preset time is a normal state, it is determined that the second adjustment strategy is not formulated.

[0105] It can be understood that only the real-time fluctuation parameters within the second preset time are analyzed to see whether they are all smaller than the preset fluctuation values: if they are all smaller than the preset fluctuation values, it is determined to be a normal state and the second adjustment strategy is not specified; if the real-time fluctuation parameters at not all times are smaller than the preset fluctuation values, it is determined to be an abnormal state, and it is necessary to increase the powder cleaning time to increase the powder removal effect.

[0106] It can be understood that the powder cleaning control module formulates an adjustment strategy for the second powder cleaning parameters based on the powder cleaning status within the second preset time; when the powder cleaning status is abnormal, the increased powder cleaning time can be scientifically and reasonably determined based on the proportional relationship between the powder cloud volume and the preset volume, so as to avoid powder residue caused by insufficient powder cleaning time and effectively improve the thoroughness of powder cleaning; and when the powder cleaning status is normal, there is no need to additionally adjust the powder cleaning time, thereby ensuring the efficiency of the powder cleaning process and the rational use of resources.

[0107] Specifically, the powder control module determines the increased powder cleaning time according to the volume ratio of the powder cloud volume at the second end time to the preset volume, wherein:

[0108] If the volume ratio is less than or equal to the preset ratio, the increased powder cleaning time is determined to be the standard time;

[0109] If the volume ratio is greater than the preset ratio, the increased powder cleaning time is determined to be the product of the standard time and the volume ratio, that is, the increased powder cleaning time = standard time × volume ratio.

[0110] It is understandable that the standard duration is usually one tenth of the duration of the set powder cleaning mode, that is, if the set powder cleaning mode is mode one, and the powder cleaning duration of mode one is 40 minutes, then the corresponding standard duration is 4 minutes.

[0111] It is understandable that, in an ideal state at the end of powder cleaning, the volume of the powder cloud should be close to zero. This is because the purpose of powder cleaning is to completely remove the powder on the surface and inside of the part. When the powder cleaning process is successfully completed, no new powder will be blown up to form a powder cloud. For example, around a simple block part that has undergone efficient powder cleaning, no obvious powder cloud should be observed through high-speed camera observation or optical detection equipment, that is, its volume can be ignored. However, in actual powder cleaning operations, due to the influence of various factors, a small amount of powder may remain, resulting in a certain volume (small volume, usually a few cubic millimeters to a few cubic centimeters) of powder cloud still being observed at the end of powder cleaning. Therefore, in implementation, the preset volume is set to 2 cubic centimeters.

[0112] In practice, the preset ratio should be greater than 1, but should be a relatively small value / close to 1. If it is set too large, it will result in a large difference from the standard for the end of powder cleaning, that is, it cannot be regarded as the end of powder cleaning. Therefore, the preset ratio is preferably set to 1.1.

[0113] It can be understood that the powder cleaning control module determines the way to increase the powder cleaning time based on the volume ratio of the powder cloud volume at the second end time to the preset volume, and can adjust the powder cleaning time according to the actual powder cleaning situation to avoid insufficient or excessive powder cleaning. While effectively improving the powder cleaning effect to approach the ideal zero powder residue state, it fully considers the characteristics of different powder cleaning modes, reasonably determines the standard time, and combines the scientific setting of preset proportions and preset volumes to ensure the accuracy and adaptability of the powder cleaning time adjustment, thereby ensuring the efficient and stable operation of the entire powder cleaning system and the high quality of parts after powder cleaning.

[0114] The flow chart and connection diagram in the accompanying drawings illustrate the possible architecture, functions and operations of the device, method and computer program product according to various embodiments of the present application. In this regard, each box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the module, a program segment or a part of a code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flow chart, and the combination of boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based device that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0115] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

[0116] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A metal printing complex flow channel powder cleaning system, characterized in that: include: Powder purifier, used to vibrate and remove residual powder from parts and recycle it without pollution; A powder collection module, which is connected to the powder cleaning machine and is used to collect the metal powder cleaned from the parts and perform preliminary separation of the metal powder; A powder cleaning monitoring module, which is connected to the powder cleaning machine and the powder collecting module respectively, and includes a dust monitoring unit and a powder monitoring unit; The dust monitoring unit is used to monitor the intake dust concentration and exhaust dust concentration at the air inlet and the exhaust port of the sealed collection box in the powder collection module in real time; The powder monitoring unit includes a plurality of video shooting components and video reconstruction components, each of which is used to shoot powder cloud videos of the powder purifier at different angles during the powder cleaning process, and the video reconstruction component is used to determine a powder cloud panoramic model according to the powder cloud videos at different angles; a powder cleaning control module, which is connected to the powder cleaning machine and the powder cleaning monitoring module respectively, and is used to determine the dust characterization state of the part according to the exhaust dust concentration at a first preset time to determine whether to determine a first adjustment strategy for a first powder cleaning parameter in combination with the dust concentration difference, determine a powder cloud change trend during the powder cleaning process according to the powder cloud panoramic model to determine a powder cleaning state, and determine a second adjustment strategy for a second powder cleaning parameter according to the powder cleaning state at a second preset time; Wherein, the first powder cleaning parameter includes powder cleaning power and negative pressure power, and the second powder cleaning parameter includes powder cleaning time; The first start time of the first preset time is the initial powder cleaning start time, and the second end time of the second preset time is the initial powder cleaning end time.

2. The metal printing complex flow channel powder cleaning system according to claim 1, characterized in that: The powder collection module includes a sealed collection box and a negative pressure generating device; The sealed collection box is used to collect the metal powder cleaned from the parts, and a powder filtering device is arranged inside the sealed collection box to perform preliminary separation of powders of different particle sizes; The negative pressure generating device is connected to the sealed collecting box and is used for sucking the powder in the cleaning process into the sealed collecting box by generating negative pressure.

3. The metal printing complex flow channel powder cleaning system according to claim 1, characterized in that: In the powder cleaning monitoring module, the dust monitoring unit includes two dust sensors respectively arranged at the air inlet and the air outlet of the sealed collection box.

4. The metal printing complex flow channel powder cleaning system according to claim 1, characterized in that: The powder cleaning control module determines the dust characterization state of the part according to the exhaust dust concentration at the first preset time to determine the first adjustment strategy of the first powder cleaning parameter, or determines the first adjustment strategy of the first powder cleaning parameter in combination with the dust concentration difference, including: If the exhaust dust concentration is greater than the concentration threshold, the dust characterization state of the part is determined to be an abnormal characterization state and a first adjustment strategy is determined according to the dust concentration difference, wherein: If the dust concentration difference is greater than or equal to the concentration difference reference value, it is determined that the first adjustment strategy is to reduce the dust cleaning power; If the dust concentration difference is less than the concentration difference reference value, it is determined that the first adjustment strategy is not formulated, and it is determined that the powder filtering device of the sealed collection box is faulty; If the exhaust dust concentration is less than or equal to the concentration threshold, it is determined that the dust characterization state of the part is a normal characterization state, and it is determined not to formulate the first adjustment strategy; The dust concentration difference is determined according to the difference between the intake dust concentration and the exhaust dust concentration.

5. The metal printing complex flow channel powder cleaning system according to claim 4, characterized in that: The powder cleaning control module determines whether to formulate the first adjustment strategy for the second time according to the dust characterization state for a preset time after reducing the powder cleaning power, including: If the dust characterization state is still the abnormal characterization state, it is determined that the first adjustment strategy is formulated for the second time, and the first adjustment strategy formulated for the second time is to maintain the reduced powder cleaning power and reduce the negative pressure power.

6. The metal printing complex flow channel powder cleaning system according to claim 1, characterized in that: The video reconstruction component converts powder cloud videos at different angles into three-dimensional point cloud data of the powder cloud at various angles through a three-dimensional reconstruction method, and forms a powder cloud panoramic model with a spatial structure based on point cloud fusion and rendering technology.

7. The metal printing complex flow channel powder cleaning system according to claim 1, characterized in that: The powder cleaning control module determines the volume time domain diagram of the powder cloud according to the real-time panoramic model of the powder cloud, and determines the powder cloud change trend during the powder cleaning process according to the real-time fluctuation parameter of the volume time domain diagram to determine the powder cleaning state, including: If the real-time fluctuation parameter at each moment is less than or equal to the preset fluctuation value, it is determined that the powder cloud change trend is a continuous decreasing trend, and the powder removal state is determined to be a normal state; If the real-time fluctuation parameter at any moment is greater than the preset fluctuation value, the powder cloud change trend is determined to be a fluctuation change trend, and the powder removal state is determined to be an abnormal state.

8. The metal printing complex flow channel powder cleaning system according to claim 7, characterized in that: The powder control module determines the real-time volume difference according to the powder cloud volume at the current moment and the powder cloud volume at the previous moment, and determines the real-time fluctuation parameter according to the percentage of the real-time volume difference to the powder cloud volume at the current moment.

9. The metal printing complex flow channel powder cleaning system according to claim 1, characterized in that: The powder control module determines a second adjustment strategy for a second powder cleaning parameter according to the powder cleaning state at a second preset time, including: If the powder clearing state at the second preset time is an abnormal state, determining that the second adjustment strategy is to increase the powder clearing time; If the powder removal state at the second preset time is a normal state, it is determined that the second adjustment strategy is not formulated.

10. The metal printing complex flow channel powder cleaning system according to claim 9, characterized in that: The powder control module determines the increased powder cleaning time according to the volume ratio of the powder cloud volume at the second end time to the preset volume, wherein: If the volume ratio is less than or equal to the preset ratio, the increased powder cleaning time is determined to be the standard time; If the volume ratio is greater than a preset ratio, the increased powder cleaning time is determined to be the product of the standard time and the volume ratio.

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