Powder supply system for metal 3D printing and control method thereof

Abstract

The invention discloses a powder supply system for metal 3D printing and a control method thereof. The system comprises a remote measurement and control device, a powder supply mechanism and a powder feeding tank, the powder supply mechanism comprises a box body, a man-machine interaction device, a controller, a powder storage tank and a circulating system, a powder inlet pipeline is installed below a filter element of the powder feeding tank, the powder feeding tank is provided with a first material level sensor, and an air outlet pipeline is installed above the filter element of the powder feeding tank; the circulating system comprises a fan, a powder feeding pipeline and an air return pipeline, and the powder feeding pipeline and the air return pipeline achieve communication of the fan and the powder feeding tank through connecting pipelines; a powder outlet of the powder storage tank is provided with a powder outlet pipeline, the installation position of the powder outlet pipeline and the powder feeding pipeline is obliquely arranged so that an acute angle can be formed between the powder outlet direction and the feeding direction of the feeding pipeline, the powder outlet pipeline is provided with a first butterfly valve, the powder storage tank is provided with a second material level sensor, and the controller controls the working states of all the components. The problems that in the current powder conveying process, powder blocking, uneven conveying and the like are prone to occurring, and therefore the printing quality and efficiency are affected are solved.

Description

Technical Field

[0001] This application relates to the technical field of additive manufacturing, specifically to a powder supply system and control method for metal 3D printing. Background Art

[0002] Metal powders, as a core material for 3D printing, are constantly being diversified, including aluminum alloys, copper alloys, titanium alloys, and others, each with its unique properties and applicable scenarios. Since metal powder preparation and performance requirements are typically high, ensuring safety, reducing contamination, minimizing waste, and improving efficiency during transportation are current challenges that need to be addressed.

[0003] In the past, conventional methods for powder supply systems in metal 3D printing have been relatively limited. Some systems use simple gravity-feeding, relying on the powder's own weight to transport it from the powder container to the forming chamber. Other systems use mechanical stirring to ensure even powder distribution. However, these methods often require frequent manual intervention, such as manually adding powder and adjusting the feeding speed. Furthermore, there is a lack of effective monitoring and control over the powder storage and delivery environment. In summary, current powder delivery methods struggle to guarantee a stable powder supply, easily leading to problems like powder clogging and uneven delivery, which negatively impact printing quality and efficiency. Summary of the Invention

[0004] This application provides a powder supply system and control method for metal 3D printing, which solves the problems of difficulty in ensuring stable powder supply, powder blockage, uneven delivery, etc., which affect printing quality and efficiency in the current powder delivery process.

[0005] The first aspect of this application provides a powder supply system for metal 3D printing, which adopts the following technical solution: A powder supply system for metal 3D printing includes a remote monitoring and control device, a powder supply mechanism, and at least one powder loading tank with a filter element. The powder supply mechanism includes a housing, a human-machine interface device mounted on the housing, a controller, a powder storage tank, and a circulation system housed within the housing. The powder loading tank's lower powder inlet communicates with the forming chamber. An upper powder inlet is located on the side wall of the upper powder tank below the filter element. A powder inlet pipe is installed at the upper powder inlet. A first material level sensor is installed below the upper powder inlet. An upper return air outlet is located above the filter element, and an air outlet pipe is installed at the upper return air outlet. The circulation system includes a fan, a powder delivery pipe, and a return air pipe. One end of the powder delivery pipe is installed at the fan outlet, and the other end is fixedly connected to the free end of the powder delivery pipe. The return air... One end of the pipe is installed at the return air inlet of the blower, and the other end of the return air pipe is fixedly connected to the free end of the outlet air pipe. The return air pipe and the outlet air pipe, as well as the powder feeding pipe and the powder inlet pipe, are all fixedly connected by connecting pipes. The powder outlet of the powder storage tank is equipped with a powder discharge pipe. The powder discharge pipe and the powder feeding pipe are installed at an angle. The angle of the powder discharge pipe is such that the powder discharge direction and the feeding direction formed by the airflow generated by the blower in the feeding pipe form an acute angle. A first butterfly valve is installed on the powder discharge pipe. A second material level sensor is installed on the powder storage tank. The first material level sensor is electrically connected to a remote monitoring and control device. The remote monitoring and control device is communicatively connected to a controller. The second material level sensor, the first butterfly valve, and the blower are all electrically connected to the controller. Universal wheels are also installed at the bottom of the box.

[0006] By adopting the above technical solution, unattended, automated, and continuous powder supply is achieved, solving the problems of limited powder storage capacity in the powder feeding structure and low efficiency and safety issues associated with manual powder feeding on large metal 3D printing equipment. Operators only need to touch a button such as "Start Powder Feeding" on the human-machine interface to activate powder feeding; the controller automates the process, eliminating manual operation, improving feeding efficiency, and ensuring employee safety. The powder outlet pipe and the powder feeding pipe are installed at an angle, and the angle between the powder outlet direction and the feeding direction is acute, facilitating smooth powder entry. The powder feeding pipeline prevents powder blockage and reduces mechanical design costs. A first level sensor continuously monitors the powder level in the upper powder tank to indicate the current powder status. A second level sensor also continuously monitors the powder level in the upper powder tank to ensure sufficient powder is always stored in the storage tank, thus achieving automatic powder feeding control. The upper powder tank, acting as a transfer structure between the storage tank and the forming chamber, forms a pressure buffer unit, preventing pressure changes in the storage tank from being directly transmitted to the forming chamber, reducing powder gushing, splashing, or other issues caused by sudden pressure changes during transport. The system features a closed-loop circulation system between the powder storage tank, powder loading tank, and forming chamber, creating an inert gas atmosphere for closed-loop powder delivery. This protects the metal powder from external environmental influences, improving powder delivery efficiency, equipment stability, and lifespan. Simultaneously, casters at the bottom of the housing facilitate the movement of the controller, powder storage tank, and circulation system installed within. Furthermore, the powder delivery pipes of the circulation system, the powder inlet pipes of the powder loading tank, and the return air pipes of the circulation system are all fixedly connected to the outlet pipes of the powder loading tank via connecting pipes. This allows the circulation system to adapt to various powder loading tanks, enabling it to handle multiple powder loading tanks. The powder supply tank enables powder supply to multiple molding chambers. It can be adapted to molding chambers that require the same type of metal powder for 3D printing, or to molding chambers that require different types of metal powder for 3D printing. Furthermore, the control and data acquisition of the powder supply tank are achieved through a remote measurement and control device. The remote measurement and control device can realize the control and data transmission of multiple powder supply tanks. That is, after the controller and the remote measurement and control device establish a communication connection, the controller sends instructions to the remote measurement and control device to realize the control of the powder supply tank and data acquisition, thereby establishing a connection with multiple powder supply tanks to realize the powder supply of multiple molding chambers.

[0007] Optionally, the powder storage tank, powder delivery pipe, and return air pipe are all equipped with pressure balancing pipes for connecting to the external environment. The pressure balancing pipes are equipped with clamp valves, which are electrically connected to the controller. The air outlet pipe and the powder inlet pipe are all equipped with second butterfly valves, which are electrically connected to the remote monitoring and control device.

[0008] By adopting the above technical solution, pressure balancing pipes and pinch valves connected to the external environment are installed on the powder storage tank, powder delivery pipe, and return air pipe. This effectively balances the pressure between the system and the external environment, preventing excessive pressure difference from affecting powder delivery. The pinch valves are electrically controlled by a controller, enabling automated pressure balancing regulation. A second butterfly valve is installed on the air outlet pipe and powder inlet pipe and electrically connected to a remote monitoring and control device. This allows for remote control of the second butterfly valve, facilitating flexible adjustment of gas and powder flow, improving system stability and reliability, and enabling automatic pipe cleaning to reduce powder blockage.

[0009] Optionally, the housing is further equipped with an inerting control device electrically connected to the controller. The housing has an inerting gas inlet connected to the inerting control device. The powder feeding pipe has a washing gas inlet, and the return air pipe has a washing gas outlet connected to an external filtration device. The inerting control device is connected to the washing gas inlet. The powder loading tank is equipped with an oxygen content detector and a temperature sensor. The powder loading tank is equipped with a pressure sensor and a pressure relief valve. The oxygen content detector, temperature sensor, pressure sensor, and pressure relief valve are all electrically connected to a remote monitoring and control device.

[0010] By adopting the above technical solution, an inerting control device electrically connected to the controller is installed inside the chamber. An inerting gas inlet is opened in the chamber and connected to the inerting control device. A washing gas inlet is opened in the powder delivery pipeline, and a washing gas outlet connected to an external filtration device is opened in the return air pipeline, with the inerting control device connected to the washing gas inlet. This allows for washing operations on the powder delivery pipeline and return air pipeline, reducing the oxygen content within the pipelines. An oxygen content detector is installed in the powder loading tank and electrically connected to a remote monitoring and control device, enabling real-time monitoring of the oxygen content within the tank. This achieves closed-loop powder delivery in an inert atmosphere, ensuring the metal powder is in a safe inert gas environment during delivery, improving the safety of personnel and equipment. Simultaneously, a pressure sensor detects the gas pressure in the powder loading tank in real-time during washing and powder supply, and sends the detected pressure value to the controller via the remote monitoring and control device. The controller controls the operation of the pressure relief valve based on the pressure value detected by the pressure sensor to ensure the powder loading tank remains in a safe state. A temperature sensor is installed in the powder loading tank to monitor the temperature in real-time, preventing potential spontaneous combustion, explosion, or other safety accidents caused by abnormal temperature increases in the metal powder due to friction, static electricity, or other factors.

[0011] Optionally, the first material level sensor includes a high material level sensor and a low material level sensor. The low material level sensor is located near the powder outlet of the upper powder tank, and the high material level sensor is located near the powder inlet of the upper tank. An alarm device is also installed on the housing, and the alarm device is electrically connected to the controller.

[0012] By adopting the above technical solution, the first material level sensor is equipped with a high-level sensor and a low-level sensor. The low-level sensor is located near the discharge port of the upper powder tank, and the high-level sensor is located near the powder inlet of the upper powder tank. This allows for more accurate detection of the powder level in the upper powder tank, providing accurate data for powder feeding control and enabling automatic powder feeding cycle. Specifically, the high-level sensor is installed below and near the powder inlet of the upper powder tank, thus preventing the powder in the upper powder tank from overflowing and causing backflow. The low-level sensor is installed near the discharge port of the upper powder tank, indicating that the current material level in the upper powder tank is low and powder needs to be added in time. In addition, a human-machine interface device and an alarm device electrically connected to the controller are installed on the housing, allowing the staff to clearly understand the status of each unit of the powder feeding system, and to promptly detect and resolve problems, thereby improving industrial efficiency.

[0013] Optionally, the filter element of the powder loading tank is equipped with a differential pressure detector for detecting the pressure difference between the two ends of the filter element. The differential pressure detector is electrically connected to a remote monitoring and control device. A backflush air manifold is installed above the filter element in the powder loading tank. The backflush air manifold is connected to the inside of the powder loading tank through an air blowing pipe. The air outlet of the air blowing pipe is located in the upstream area of ​​the airflow channel of the filter element inside the powder loading tank. A backflush pulse valve is provided on the air blowing pipe. The backflush pulse valve is electrically connected to a controller so that the controller can control the opening and closing of the backflush pulse valve.

[0014] By adopting the above technical solution, the differential pressure detector can detect the pressure difference between the two ends of the filter element in the powder tank and feed the data back to the remote monitoring and control device. When an abnormal pressure difference is detected in the filter element, the controller can control the backflush pulse valve to open, so that the backflush air manifold releases gas into the upstream area of ​​the airflow channel of the filter element through the air blowing pipe for backflush, cleaning the powder accumulated on the filter element, solving the filter element blockage problem, ensuring smooth powder feeding, thereby improving powder feeding efficiency, and maintaining the pressure balance in the powder tank to ensure the stable operation of the entire powder supply system.

[0015] Optionally, a manual butterfly valve may also be installed on the powder outlet pipe.

[0016] By adopting the above technical solution, the opening and closing of the powder supply pipeline can be manually controlled, which facilitates manual intervention and adjustment of the powder supply when necessary, and enhances the flexibility of system operation.

[0017] The second aspect of this application provides a control method for a powder supply system for metal 3D printing, employing the following technical solution: A control method for a safety handling system for additive manufacturing, applied to the system as described in the first aspect, the method comprising: In response to the powder delivery request, open the second butterfly valve; Based on the powder feeding request, the current state of the second level sensor is obtained, and based on the current state of the second level sensor, it is determined whether the remaining amount of powder in the current powder storage tank meets the powder feeding requirements. If the current state of the second level sensor determines that the remaining amount of powder in the current powder storage tank is equal to or lower than the preset minimum level, a powder replenishment signal is generated to control the alarm device to issue an alarm to prompt the operator to replenish the powder. Based on the powder delivery request, the current oxygen content data detected by the oxygen content detection sensor is obtained, and based on the current oxygen content data, it is determined whether the current oxygen content of the powder loading tank, powder delivery pipeline and return air pipeline is lower than the preset safety threshold. If, based on the current oxygen content data, it is determined that the current oxygen content of the powder supply tank, powder delivery pipeline, and return air pipeline is higher than or equal to a preset safety threshold, a gas scrubbing command is generated to control the gas scrubbing control device and the second butterfly valve to open. When the oxygen content detection sensor determines that the current oxygen content of the powder feeding tank, powder delivery pipeline and return air pipeline is lower than the preset safety threshold, a gas washing stop command is generated to control the gas washing control device to shut down. When the remaining amount of powder in the powder storage tank meets the powder delivery requirements and the current oxygen content is lower than the preset safety threshold, the control fan, the first butterfly valve and the second butterfly valve are opened. After a first preset time, the first butterfly valve is opened so that the fan can deliver the powder to the powder loading tank. In response to the request to stop powder feeding, the first butterfly valve is closed, and the second butterfly valve and the fan are closed after a second preset time.

[0018] By adopting the above technical solution, when responding to a powder feeding request, the remaining powder level in the powder storage tank can be determined by acquiring the status of the second material level sensor. When the remaining powder level is equal to or lower than the preset minimum material level, an alarm is promptly triggered to remind the operator to replenish powder, avoiding the disruption of normal 3D printing operations due to insufficient powder. Simultaneously, by acquiring the current oxygen content data detected by the oxygen content detection sensor, the oxygen content in the powder supply tank, powder feeding pipe, and return air pipe is determined. When the oxygen content is higher than or equal to the preset safety threshold, a gas purging operation is promptly performed to ensure that the oxygen content in the system is within a safe range, reducing safety risks such as metal powder oxidation and explosion. When the remaining powder level in the powder storage tank meets the powder feeding requirements and the oxygen content is lower than the preset safety threshold, the system controls the fan and other equipment to send powder to the powder supply tank, achieving efficient and safe powder supply. When responding to a powder feeding stop request, the corresponding valves and fans are closed for a preset duration to ensure the stability and safety of the system when powder feeding stops, improving the reliability and efficiency of the metal 3D printing process.

[0019] Optionally, after opening the first butterfly valve after a first preset time period, the process further includes: Acquire dynamic level data from the first level sensor; When the remaining powder level in the powder storage tank is determined to be lower than or equal to the preset minimum level based on the detection data of the first material level sensor, a stop processing command is generated, the first butterfly valve is controlled to close and the alarm device is controlled to sound an alarm, and after a second preset time, the blower and the second butterfly valve are controlled to close. When the amount of powder remaining in the powder storage tank is higher than the preset minimum level based on the dynamic level data of the first level sensor, the powder level data of the second level sensor is obtained. When the powder level data from the second level sensor is determined to be at or above the level of the high level sensor, a pause processing command is generated, and the first butterfly valve is closed. If, based on the dynamic level data from the second level sensor, it is determined that the powder in the current powder feeding tank remains at or above the position of the high level sensor for a continuous second preset time, a stop processing command is generated, controlling the first butterfly valve to close and the alarm device to sound an alarm. After the second preset time, the blower and the second butterfly valve are controlled to close. When the powder level data from the second level sensor is determined to be lower than the position of the high level sensor and / or at or below the position of the low level sensor, a command to continue feeding powder is generated, controlling the first butterfly valve to open and continue feeding powder into the powder tank.

[0020] By adopting the above technical solution, during the powder feeding process, the remaining powder in the powder storage tank can be monitored in real time based on the dynamic level data of the first level sensor. When the remaining powder is lower than or equal to the preset minimum level, a stop processing command can be generated in a timely manner, closing the first butterfly valve and triggering an alarm. Subsequently, the blower and the second butterfly valve are shut down to avoid situations where there is no powder to feed, ensuring the continuity and stability of the powder feeding process. Furthermore, the position of the powder in the feeding tank can be determined based on the powder level data from the second level sensor. When the powder is at or above the position of the high level sensor, powder feeding is paused to prevent powder from being added to the tank. The powder overflow prevention system improves the safety of powder feeding. If, after the second preset time, the powder level in the powder feeding tank is still at or above the position of the high-level sensor, the powder feeding tank may experience a powder feeding failure or the forming chamber may suspend processing. In this case, powder feeding will be stopped to prevent powder overflow from the powder feeding tank. When the powder level is below the position of the high-level sensor and / or at or below the position of the low-level sensor, a powder feeding command will be generated in a timely manner to ensure that the powder feeding tank has a sufficient powder supply. This achieves automatic powder feeding without manual intervention, improves powder feeding efficiency, and reduces labor costs.

[0021] Optionally, after opening the first butterfly valve after a first preset time period, the process further includes: Obtain the current temperature value detected by the temperature sensor, and compare the current temperature value with a preset safe temperature value; If the current temperature value is greater than or equal to the preset safety threshold, a stop processing command is generated, controlling the first butterfly valve, the fan, and the second butterfly valve to close and triggering an alarm.

[0022] By adopting the above technical solution, the current temperature value detected by the temperature detection sensor is obtained in real time during the powder feeding process and compared with the preset safe temperature value. When the current temperature value is greater than or equal to the preset safe threshold, a stop processing command can be generated in time to close the first butterfly valve, the fan and the second butterfly valve and control the alarm device to alarm, thereby realizing temperature loss protection, avoiding damage to the equipment and powder feeding process due to abnormal temperature, and ensuring the stability and service life of the equipment.

[0023] Optionally, after closing the second butterfly valve and the blower after the second preset time period, the process further includes: The clamp valve is opened and then closed after a third preset time period.

[0024] By adopting the above technical solution, after closing the second butterfly valve and the fan, the pinch valve is opened to keep the pressure of the powder storage tank, powder supply pipeline and return air pipeline in a balanced state with the external environment. This prevents the powder conveying from being affected by excessive pressure difference, ensures stable system pressure, and facilitates the normal operation and maintenance of the system. At the same time, closing the pinch valve after the third preset time can prevent impurities in the external environment from entering the powder storage tank, powder supply pipeline and return air pipeline and causing pollution to the powder supply system.

[0025] In summary, one or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages: 1. Achieve automatic powder feeding without human intervention. The system monitors the remaining amount of powder through remote monitoring and control devices, controllers, and material level sensors. It automatically controls the switching of equipment such as fans and butterfly valves according to preset conditions, achieving unattended, automated, and continuous powder feeding, thereby improving powder delivery efficiency. 2. It has a special anti-clogging structure. The powder outlet pipe and the powder delivery pipe of the powder storage tank are installed at an angle. The angle between the powder outlet direction and the airflow delivery direction in the delivery pipe is an acute angle, which is conducive to the smooth entry of powder into the delivery pipe. Combined with the circulation system, it reduces the probability of powder blockage and realizes the anti-powder jamming and powder blockage control design at the program end, reducing mechanical design costs. 3. Achieve closed-loop powder feeding in an inert atmosphere. Through inerting control devices, oxygen content detectors, etc., the powder feeding and gas circulation process is protected by an inert gas atmosphere throughout, which can effectively prevent powder oxidation, while not interfering with the molding chamber, ensuring the safety of the powder feeding process, reducing powder contamination, and reducing losses. Attached Figure Description

[0026] Figure 1 This is a rear side view schematic diagram of a powder supply system for metal 3D printing disclosed in an embodiment of this application; Figure 2 This is a front view schematic diagram of a powder supply system for metal 3D printing disclosed in an embodiment of this application; Figure 3 This is a schematic diagram of the structure of each device inside the box of a powder supply system for metal 3D printing disclosed in an embodiment of this application; Figure 4 This is a schematic diagram of the circulation system of a powder supply system for metal 3D printing disclosed in an embodiment of this application; Figure 5 This is a schematic diagram of the powder loading tank of a powder supply system for metal 3D printing disclosed in an embodiment of this application; Figure 6 This is a cross-sectional view of the powder feeding tank of a powder supply system for metal 3D printing disclosed in an embodiment of this application; Figure 7 This is another cross-sectional view of the powder loading tank of a metal 3D printing powder supply system disclosed in the embodiments of this application; Figure 8 This is a flowchart illustrating a control method for a powder supply system for metal 3D printing disclosed in an embodiment of this application.

[0027] Explanation of reference numerals in the attached diagram: 1. Housing; 11. Controller; 121. Powder storage tank; 122. Second level sensor; 123. Powder outlet pipe; 124. First butterfly valve; 125. Manual butterfly valve; 13. Circulation system; 131. Fan; 132. Powder delivery pipe; 133. Return air pipe; 14. Casters; 15. Human-machine interface device; 16. Alarm device; 171. Inerting control device; 172. Inerting gas inlet; 173. Washing gas inlet; 174. Washing gas outlet; 2. Upper powder tank; 21. Upper tank powder inlet; 22. Powder inlet pipe; 2 3. Upper tank return air inlet; 24. Air outlet duct; 25. Second butterfly valve; 26. Pressure sensor; 27. Pressure relief valve; 28. Oxygen content detector; 29. ​​Backflush air manifold; 20. First material level sensor; 201. High material level sensor; 202. Low material level sensor; 210. Temperature detection sensor; 211. Differential pressure detector; 3. Connecting pipe; 4. Pressure balancing pipe; 41. Pinch valve; 500. Electronic equipment; 501. Processor; 502. Communication bus; 503. User interface; 504. Network interface; 505. Memory. Detailed Implementation

[0028] In order to enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below in conjunction with the drawings in the embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this application, not all of the embodiments.

[0029] In the description of the embodiments of this application, the words "for example" or "for instance" are used to indicate examples, illustrations, or explanations. Any embodiment or design that is described as "for example" or "for instance" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design options. Rather, the use of the words "for example" or "for instance" is intended to present the relevant concepts in a specific manner.

[0030] In the description of the embodiments of this application, the term "multiple" means two or more. For example, multiple systems means two or more systems, and multiple screen terminals means two or more screen terminals. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. The terms "comprising," "including," "having," and variations thereof all mean "including but not limited to," unless otherwise specifically emphasized.

[0031] like Figure 1-7 As shown, the system includes a remote monitoring and control device 5, a powder supply mechanism, and at least one powder loading tank 2 with a filter element. The remote monitoring and control device 5 works in conjunction with the powder supply mechanism and the powder loading tank 2 to achieve precise monitoring and control of the powder supply process, thereby ensuring stable powder delivery and achieving automated continuous powder supply.

[0032] Specifically, the remote monitoring and control device 5 functions as a remote I / O module in this system, mainly performing the following functions: Data acquisition: It is electrically connected to the first level sensor 20, oxygen content detector 28, temperature sensor 210, pressure sensor 26, differential pressure detector 211, and other detection components to collect the detection data of each component in real time; Signal transmission: It establishes a communication connection with the controller 11 through an industrial Ethernet to transmit the collected detection data to the controller 11, and at the same time receives control commands issued by the controller 11; Execution control: It is electrically connected to the second butterfly valve 25 and other execution components to control the actions of the execution components according to the commands of the controller 11 or the preset control logic.

[0033] The powder supply mechanism includes a housing 1, a human-machine interface device 15, a controller 11, a powder storage tank 121, and a circulation system 13. The housing 1 provides a relatively enclosed installation space for the entire powder supply mechanism, and its bottom is equipped with casters 14 for easy movement and position adjustment. The human-machine interface device 15 is mounted on the housing 1, allowing operators to input commands and view system status. The human-machine interface device 15 can be in the form of a touchscreen, buttons, etc. For example, a touchscreen-type human-machine interface device 15 is intuitive and convenient to operate and can display various system parameters in real time. In this embodiment, the human-machine interface device 15 is a suspended HMI touchscreen. A hook is fixedly installed on the housing 1, and the suspended HMI touchscreen is fixed to the housing 1 in conjunction with the hook. A through hole is provided on the side wall of the housing 1 to allow cables for electrical connection between the human-machine interface device 15, the alarm device 16, and the controller 11 to pass through.

[0034] Understandably, operators can set parameters such as powder feeding amount and safety threshold through the human-machine interface device 15, and can also view the system operating status, such as material level information and temperature data.

[0035] The circulation system 13 includes a fan 131, a powder feeding pipe 132, and a return air pipe 133, forming an airflow circulation loop for powder conveying. The fan 131 can be a variable frequency fan 131, installed inside the housing 1. Its air outlet is connected to one end of the powder feeding pipe 132, and its return air outlet is connected to one end of the return air pipe 133. The other end of the powder feeding pipe 132 is fixedly connected to the free end of the powder inlet pipe 22 of the upper powder tank 2 through a connecting pipe 3. The other end of the return air pipe 133 is fixedly connected to the free end of the air outlet pipe 24 of the upper powder tank 2 through a connecting pipe 3. The connecting pipe 3 is made of copper wire flexible hose, which has good flexibility and sealing performance, can compensate for installation errors and absorb displacement caused by equipment vibration, and can also achieve the connection between the circulation system 13 and the upper powder tank 2 by using different models of connecting pipe 3, so that the same powder supply mechanism can be used to feed powder to different upper powder tanks 2.

[0036] The powder storage tank 121 inside the housing 1 is used to store the metal powder to be transported. The powder storage tank 121 is made of stainless steel, which has good sealing and corrosion resistance. A second level sensor 122 is installed inside the powder storage tank 121. The second level sensor 122 can detect the remaining powder in the powder storage tank 121 in real time. The second level sensor 122 is electrically connected to the controller 11 and transmits the detected level data to the controller 11 in real time. When the remaining powder in the powder storage tank 121 is lower than the preset minimum level, the controller 11 will immediately send a powder replenishment signal to remind the operator to replenish the metal powder in the powder storage tank 121 in time. This can effectively ensure that the powder quantity in the powder storage tank 121 is always maintained within a reasonable range, ensuring the stable and continuous operation of the entire powder supply system, avoiding interruptions in the 3D printing process due to insufficient powder, or safety hazards and resource waste caused by excessive powder.

[0037] The second level sensor 122 can be a capacitive level sensor, an ultrasonic level sensor, etc. Capacitive level sensors have advantages such as high sensitivity and easy installation.

[0038] A powder outlet pipe 123 is installed at the powder outlet of the powder storage tank 121. The powder outlet pipe 123 is connected to the powder delivery pipe 132 of the circulation system 13. The powder outlet pipe 123 and the powder delivery pipe 132 are installed at an angle. The angle makes the angle between the powder outlet direction and the feeding direction formed by the airflow generated by the blower 131 in the powder delivery pipe 132 acute. This allows the powder to enter the powder delivery pipe 132 more smoothly by utilizing the traction force of the airflow and the weight of the powder itself, reducing the accumulation and blockage of powder at the pipe connection.

[0039] A first butterfly valve 124 is installed on the powder outlet pipe 123. The first butterfly valve 124 is an electric butterfly valve and is electrically connected to the controller 11. The controller 11 controls the powder supply from the powder storage tank 121 to the powder delivery pipe 132 by controlling the opening and closing of the first butterfly valve 124. A manual butterfly valve 125 is also installed on the powder outlet pipe 123. The opening and closing of the powder outlet pipe 123 can be controlled by manually operating the manual butterfly valve 125, thereby improving the reliability of the system.

[0040] The controller 11 is housed within the housing 1. It is the core control unit of the entire powder supply mechanism, responsible for receiving and processing data from various sensors and controlling the operation of each component according to a preset program. In this embodiment, a PLC controller 11 is used as an example. However, other types of controllers 11 capable of implementing this solution can also be applied, such as microcontrollers, microprocessors, or other programmable logic control units. These controllers 11 can all process sensor signals according to preset logic programs and output corresponding control commands. Furthermore, the controller 11 also has an expansion interface for connecting other auxiliary equipment, such as a human-machine interface device 15 or an alarm device 16, thereby improving the system's ease of operation and intelligence.

[0041] The enclosure 1 is also equipped with an alarm device 16 that is electrically connected to the controller 11. The alarm device 16 may include a power-on indicator light, an abnormal alarm light, and a buzzer. The power-on indicator light is used to indicate whether each device in the enclosure 1 is powered on. The abnormal alarm light is used to prompt the operator whether there is an abnormality in the current powder feeding system. The buzzer is used to emit a high-decibel warning sound when the system has a serious fault or an emergency, so that it can still attract attention in time when the light is insufficient or the operator's line of sight is not focused on the indicator light. This ensures that the operator can quickly detect the abnormality and take corresponding measures to avoid affecting the normal operation of the powder supply system due to the failure to deal with the fault in time, or even causing more serious production safety problems.

[0042] An inerting control device 171 is installed inside the housing 1. The inerting control device 171 is electrically connected to the controller 11. An inerting gas inlet 172 is provided on the housing 1. The inerting gas inlet 172 is connected to the inerting control device 171 through a pipeline for introducing inert gas (such as argon). A washing gas inlet 173 is provided on the powder feeding pipeline 132, and a washing gas outlet 174 is provided on the return air pipeline 133. The washing gas outlet 174 is connected to an external filtration device. After filtration by the external filtration device, the gas is discharged into the external environment to avoid pollution. The inerting control device 171 is connected to the washing gas inlet 173 through a pipeline. An oxygen content detector 28 is installed inside the powder loading tank 2 to detect the oxygen content in the system. The oxygen content detector 28 is electrically connected to the remote monitoring and control device 5 to transmit the detection data.

[0043] The powder inlet of the powder tank 2 is connected to the forming chamber, providing the forming chamber with the powder required for printing. The powder tank 2 has a powder inlet 21 on its side wall below the filter element. A powder inlet pipe 22 is installed at the powder inlet. A first level sensor 20 is installed below the powder inlet 21 to monitor the powder level in the powder tank 2. The first level sensor 20 includes a high level sensor 201 and a low level sensor 202. The low level sensor 202 is located near the powder inlet of the powder tank 2, and the high level sensor 201 is located near the powder inlet 21. When the powder level is lower than the low level sensor 202, it indicates that there is insufficient powder in the powder tank 2, and it needs to be replenished; when the powder level is higher than the high level sensor 201, it indicates that there is too much powder in the powder tank 2, and the powder supply needs to be stopped. The powder tank 2 is located above the filter element and has an upper tank return air port 23. An air outlet duct 24 is installed at the upper tank return air port 23 to discharge the gas in the circulation process. A second butterfly valve 25 is installed on both the air outlet duct 24 and the powder inlet duct 22. The second butterfly valve 25 is electrically connected to the remote monitoring and control device 5. The remote monitoring and control device 5 can control the opening and closing of the second butterfly valve 25 according to the actual situation to adjust the powder conveying and return air.

[0044] Understandably, to prevent powder from colliding with the side wall of the upper powder tank 2 and flowing back into the powder inlet 22 when entering the upper powder tank 2 from the powder inlet pipe 22, the powder inlet 21 of the upper tank is designed in an oval shape. This effectively guides the powder to slide down the curved inner wall, reducing the direct impact area between the powder and the tank wall, thereby reducing the backflow force. At the same time, the oval-shaped opening structure, while ensuring the powder inlet flow rate, creates a relatively stable flow state for the powder when entering the upper powder tank 2 through a gradual cross-sectional transition, further weakening the backflow phenomenon and ensuring that the powder can smoothly enter the tank, improving the stability and efficiency of the powder replenishment process.

[0045] The filter element in powder loading tank 2 serves a filtering function, filtering the powder. Under the influence of gravity, the powder falls from the filter element to the powder outlet of powder loading tank 2, thus supplying powder to the forming chamber. The filter element can be made of paper or metal. Paper filter elements have good filtration effect and low cost, while metal filter elements have advantages such as high strength and long service life. The filter element in powder loading tank 2 is equipped with a differential pressure detector 211 to detect the pressure difference across the filter element. When the pressure difference across the filter element is too large, it indicates that the filter element may be clogged and needs to be cleaned or replaced. A backflush air manifold 29 is installed above the filter element in powder loading tank 2. The backflush air manifold 29 is connected to the inside of powder loading tank 2 through an air blowing pipe. The air outlet of the air blowing pipe is located in the upstream area of ​​the airflow channel of the filter element inside powder loading tank 2. A backflush pulse valve is installed on the air blowing pipe. The backflush pulse valve is electrically connected to the controller 11 so that the controller 11 can control the opening and closing of the backflush pulse valve. When the filter element needs cleaning, the controller 11 controls the backflush pulse valve to open, and the gas in the backflush air tank 29 is quickly blown out to backflush the filter element and remove the powder attached to the filter element.

[0046] The powder storage tank 121, the powder delivery pipe 132, and the return air pipe 133 are all equipped with pressure balancing pipes 4 for connecting to the external environment. A pinch valve 41 is installed on the pressure balancing pipe 4, and the pinch valve 41 is electrically connected to the controller 11. After powder delivery is completed, the pinch valve 41 is opened to achieve pressure balance between the powder storage tank 121, the powder delivery pipe 132, and the return air pipe 133 and the external environment, preventing damage to the pipes or obstruction of powder delivery due to excessive pressure.

[0047] A pressure sensor 26 and a pressure relief valve 27 are installed inside the powder loading tank 2. The pressure sensor 26 is used to detect the pressure inside the powder loading tank 2, and the pressure relief valve 27 is used to automatically release pressure when the pressure inside the powder loading tank 2 exceeds a safety threshold. Both the pressure sensor 26 and the pressure relief valve 27 are electrically connected to the remote monitoring and control device 5. A temperature detection sensor 210 is also installed inside the powder loading tank 2 to detect the temperature inside the powder loading tank 2. The temperature detection sensor 210 is electrically connected to the remote monitoring and control device 5 and transmits the temperature data to the remote monitoring and control device 5 in real time.

[0048] The inerting control device 171 can inject inerting gas into the powder feeding pipeline 132 to reduce the oxygen content in the system and prevent oxidation and other reactions of the metal powder. The oxygen content detector 28 monitors the oxygen content in the powder loading tank 2 in real time. When the oxygen content exceeds a preset safety threshold, the remote control device 5 controls the inerting control device 171 and the second butterfly valve 25 to open for gas washing. When the oxygen content is below the preset safety threshold, the remote control device 5 controls the inerting control device 171 to close. The temperature detection sensor 210 monitors the temperature in the powder loading tank 2 in real time. When the temperature is too high, the remote control device 5 controls relevant components to stop working to prevent safety accidents. The pressure sensor 26 monitors the pressure in the powder loading tank 2 in real time. When the pressure is too high, the pressure relief valve 27 automatically opens to release the pressure and ensure system safety.

[0049] In this embodiment, the powder supply system achieves precise control over the supply of metal 3D printing powder through the coordinated operation of the remote monitoring and control device 5, the powder supply mechanism, and the powder loading tank 2. The circulation system 13 enables the powder to circulate within the system, improving powder utilization and conveying efficiency. The use of multiple sensors, such as the first level sensor 20, the second level sensor 122, the oxygen content detector 28, the temperature sensor 210, and the pressure sensor 26, monitors various system parameters in real time. The controller 11 performs corresponding control based on these parameters, ensuring the stability and accuracy of the powder supply. Simultaneously, the inerting control device 171 reduces the oxygen content within the system, improving system safety. Compared with existing technologies, this system solves the problems of low efficiency, easy introduction of impurities, and lack of monitoring and control mechanisms in traditional powder supply methods, meeting the stringent requirements of metal 3D printing for powder supply.

[0050] like Figure 8 As shown, a control method for a powder supply system for metal 3D printing provided in this application embodiment includes the following steps: S1, in response to the powder delivery request, opens the second butterfly valve.

[0051] S2, based on the powder feeding request, obtain the current state of the second level sensor, and based on the current state of the second level sensor, determine whether the remaining amount of powder in the current powder storage tank meets the powder feeding requirements.

[0052] S3, if the current powder level in the powder storage tank is determined to be equal to or lower than the preset minimum level based on the current state of the second level sensor, a powder replenishment signal is generated to control the alarm device to issue an alarm to prompt the operator to replenish the powder.

[0053] S4, and obtain the current oxygen content data detected by the oxygen content detection sensor according to the powder feeding request, and determine whether the current oxygen content of the current powder feeding tank, powder feeding pipeline and return air pipeline is lower than the preset safety threshold based on the current oxygen content data.

[0054] S5. If the current oxygen content of the powder supply tank, powder delivery pipeline and return air pipeline is determined to be higher than or equal to the preset safety threshold based on the current oxygen content data, a gas scrubbing command is generated to control the gas scrubbing control device to open.

[0055] S6, when the current oxygen content data detected by the oxygen content detection sensor determines that the current oxygen content of the current powder tank, powder delivery pipeline and return air pipeline is lower than the preset safety threshold, a gas washing stop command is generated to control the gas washing control device to shut down.

[0056] S7, when the remaining amount of powder in the powder storage tank meets the powder delivery requirements and the current oxygen content is lower than the preset safety threshold, control the fan, the first butterfly valve and the second butterfly valve to open, and open the first butterfly valve after a first preset time period so that the fan can deliver the powder to the powder loading tank.

[0057] S8 responds to the request to stop powder feeding, closes the first butterfly valve, and closes the second butterfly valve and the fan after a second preset time.

[0058] In this embodiment, when the molding chamber needs powder, the operator issues a powder feeding request on the human-machine interface 15. After receiving the powder feeding request, the controller 11 controls the second butterfly valve 25 to open, preparing for airflow circulation and powder delivery.

[0059] The controller 11 acquires the powder remaining amount data detected by the second material level sensor 122 in the powder storage tank 121, and determines whether the powder remaining amount meets the powder feeding requirements. If the powder remaining amount is equal to or lower than the preset minimum material level, the controller 11 generates an alarm signal, controls the alarm device 16 to issue an alarm, and prompts the operator to replenish the powder storage tank 121 in time; if the powder remaining amount meets the powder feeding requirements, the next operation is performed.

[0060] The remote monitoring and control device 5 acquires the current oxygen content data detected by the oxygen content detector 28 and transmits the acquired data to the controller 11. The controller 11 determines whether the oxygen content in the powder tank 2, the powder delivery pipeline 132, and the return air pipeline 133 is lower than a preset safety threshold based on the current oxygen content data. If the oxygen content is higher than or equal to the preset safety threshold, the controller 11 generates a gas rinsing command, controls the inerting control device 171 and the second butterfly valve 25 to open, and introduces inert gas into the system to replace the air in the system; when the oxygen content detector 28 detects that the oxygen content is lower than the preset safety threshold, the controller 11 generates a gas rinsing stop command, controls the inerting control device 171 to close, and stops the introduction of inert gas.

[0061] The preset safety threshold is 100ppm.

[0062] When the remaining amount of powder in the powder storage tank 121 meets the powder delivery requirements and the oxygen content in the system is lower than the preset safety threshold, the controller 11 controls the fan 131 to start and the second butterfly valve 25 to remain open. After a first preset time, the controller controls the first butterfly valve 124 to open. Under the action of the airflow generated by the fan 131, the powder in the powder storage tank 121 enters the powder tank 2 through the powder outlet pipe 123, the powder delivery pipe 132 and the powder inlet pipe 22.

[0063] The first preset duration can be 5 to 20 seconds, such as 5 seconds, 8 seconds, 10 seconds, 15 seconds, etc. The setting of the first preset duration is that under the action of the fan 131, the gas between the circulation system 13 and the powder tank 2 is circulated first, which can effectively clean the remaining powder in the pipeline.

[0064] During the powder feeding process, the status of the powder storage tank 121 and the powder loading tank 2 is monitored to obtain real-time data on the remaining powder in the powder storage tank 121 and key parameters such as pressure and temperature in the powder loading tank 2, thereby ensuring the stability and safety of the powder feeding process. Specifically: The dynamic level data of the first level sensor 20 is acquired; when the remaining powder in the powder storage tank 121 is lower than or equal to the preset minimum level based on the detection data of the first level sensor 20, a stop processing command is generated, controlling the first butterfly valve 124 to close and the alarm device 16 to sound an alarm; after a second preset time, the blower 131 and the second butterfly valve 25 are controlled to close; when the remaining powder in the powder storage tank 121 is higher than the preset minimum level based on the dynamic level data of the first level sensor 20, the powder loading level data of the second level sensor 122 is acquired; based on the powder loading level data of the second level sensor 122... When the material level data determines that the powder in the current powder feeding tank 2 is at or above the position of the high material level sensor 201, a pause processing command is generated, and the first butterfly valve 124 is closed. If the dynamic material level data of the second material level sensor 122 determines that the powder in the current powder feeding tank 2 remains at or above the position of the high material level sensor 201 for a second preset time, a stop processing command is generated, the first butterfly valve 124 is closed, and the alarm device 16 is activated. After the second preset time, the blower 131 and the second butterfly valve 25 are closed. When the powder level data of the second material level sensor 122 determines that the powder in the current powder feeding tank 2 is below the position of the high material level sensor 201 and / or at or below the position of the low material level sensor 202, a continue powder feeding command is generated, the first butterfly valve 124 is opened, and powder continues to be fed into the powder feeding tank 2.

[0065] Specifically, a multi-level safety assurance system is constructed through multi-sensor data fusion and a hierarchical response mechanism. When the powder level in the powder storage tank 121 reaches the preset minimum material level threshold, the system immediately triggers an emergency shutdown procedure. The first butterfly valve 124 is closed to cut off the powder conveying path, and the alarm device 16 is simultaneously activated to prompt operator intervention. After the residual powder is cleaned up within a second preset time period, the blower 131 and the second butterfly valve 25 are shut down sequentially to prevent residual powder from clogging or causing moisture in the pipeline. For the material level monitoring of the powder tank 2, a dual-threshold judgment logic is used. When the powder level reaches or exceeds the position of the high-level sensor 201, the system first generates a pause processing command and closes the first butterfly valve 124, allowing the powder a buffer time for natural settling. If the high-level state continues for more than the second preset time period, it is determined to be an abnormal accumulation risk, and the system immediately escalates to a stop processing command and activates an alarm to ensure safe equipment operation. When the powder level is below the high level and has not reached the low level, the system automatically executes a continue powder feeding command, maintaining a stable powder supply by opening the first butterfly valve 124, thus achieving continuous processing. This dynamic adjustment mechanism avoids printing interruptions due to insufficient powder and prevents equipment overload caused by excessive powder feeding, effectively improving the stability and safety of powder supply during metal 3D printing.

[0066] It is conceivable that the temperature may rise abnormally during the powder feeding process due to friction, static electricity or other factors. Therefore, by setting a temperature detection sensor 210 in the powder feeding tank 2 to monitor the temperature in the powder feeding tank 2 in real time, safety accidents such as spontaneous combustion and explosion can be avoided. Specifically, the current temperature value detected by the temperature detection sensor 210 is obtained and compared with the preset safe temperature value. If the current temperature value is greater than or equal to the preset safe temperature value, a stop processing command is generated, which controls the first butterfly valve 124, the fan 131 and the second butterfly valve 25 to close and controls the alarm device 16 to sound an alarm.

[0067] Understandably, to further improve the timeliness and reliability of temperature anomaly handling, the system is equipped with a three-level temperature warning mechanism. When the current temperature value is detected to reach 80% of the preset safe temperature value, a level one warning is triggered. At this time, the system only issues an audible and visual warning through the alarm device 16, while maintaining the normal operation of the powder feeding process, so that operators can conduct preliminary investigations before the temperature reaches the danger threshold. If the temperature continues to rise to 90% of the preset safe temperature value, it enters a level two warning state. The system automatically reduces the powder feeding rate and turns on the external cooling fan of the powder loading tank 2 to suppress further temperature rise through physical cooling. When the temperature reaches or exceeds the preset safe temperature value, an emergency shutdown procedure is immediately executed. In addition to closing the first butterfly valve 124, the fan 131, and the second butterfly valve 25, the inert gas injection device inside the powder loading tank 2 is simultaneously activated to quickly reduce the oxygen concentration inside the tank, eliminating the risk of spontaneous combustion or explosion from the source. In addition, the temperature detection sensor 210 adopts a distributed arrangement scheme, with one detection point set at the top, middle and bottom of the tank. The average temperature of the three points is taken as the current temperature value, avoiding misjudgment due to single sensor failure or local temperature deviation, and ensuring the accuracy of temperature monitoring data.

[0068] Upon receiving a request to stop powder feeding, controller 11 responds by first closing the first butterfly valve to stop the powder storage tank 121 from supplying powder to the powder feeding pipeline 132. After a second preset time, controller 11 closes the second butterfly valve and the blower 131 to stop airflow circulation. After closing the second butterfly valve and the blower 131 after the second preset time, controller 11 opens the pinch valve 41 to balance the internal and external pressures of the system. After a third preset time, controller 11 closes the pinch valve 41, completing the entire powder feeding process.

[0069] The second preset duration can be 30 to 50 seconds, such as 30 seconds, 35 seconds, 40 seconds, 42 seconds, 45 seconds, 50 seconds, etc. The purpose of setting the second preset duration is to clean up the accumulated powder during powder feeding, making the equipment safer, preventing blockages, and extending the service life of the equipment.

[0070] The third preset duration can be 1 to 10 seconds, such as 2 seconds, 3 seconds, 5 seconds, etc. The setting of the third preset duration is to ensure that the powder storage tank 121, the powder delivery pipe 132 and the return air pipe 133 form a pressure balance with the external environment, and to prevent impurities in the external environment from entering the powder storage tank 121, the powder delivery pipe 132 and the return air pipe 133.

[0071] In this embodiment, a remote monitoring and control device 5 is used to realize distributed data acquisition and control, improving the system's response speed and control accuracy. The inclined setting of the powder outlet pipe 123 and the powder delivery pipe 132 of the powder storage tank 121, combined with the airflow generated by the fan 131, improves the smoothness of powder delivery and reduces pipe blockage. The system integrates multiple monitoring functions such as material level detection, oxygen content detection, temperature detection, and pressure detection, and, together with the alarm device 16 and emergency control measures, significantly improves the safety of system operation. The system achieves fully automated control of powder supply, reduces manual intervention, and improves the production efficiency and stability of metal 3D printing. The system also includes a filter cleaning system and a pressure balancing system, which reduce system maintenance costs and extend the service life of the equipment.

[0072] The above description is merely an exemplary embodiment of this disclosure and should not be construed as limiting the scope of this disclosure. Any equivalent changes and modifications made in accordance with the teachings of this disclosure shall still fall within the scope of this disclosure. Other embodiments of this disclosure will be readily apparent to those skilled in the art upon consideration of the disclosure herein.

[0073] This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not described in this disclosure. The specification and embodiments are to be considered exemplary only, and the scope and spirit of this disclosure are defined by the claims.

Claims

1. A powder supply system for metal 3D printing, characterized in that, The system includes a remote monitoring and control device (5), a powder supply mechanism, and at least one powder supply tank (2) with a filter element. The powder supply mechanism includes a housing (1), a human-machine interface device (15) installed on the housing (1), a controller (11), a powder storage tank (121), and a circulation system (13) installed inside the housing (1). The powder outlet of the powder supply tank (2) is connected to the forming chamber. The powder supply tank (2) has a powder inlet (21) on its side wall below the filter element. A powder inlet pipe (22) is installed at the powder inlet opening of the powder supply tank. Below the powder inlet (21) of the powder supply tank... A first material level sensor (20) is installed. The powder tank (2) is located above the filter element and has an upper tank return air port (23). An air outlet pipe (24) is installed at the upper tank return air port (23). The circulation system (13) includes a blower (131), a powder feeding pipe (132), and a return air pipe (133). One end of the powder feeding pipe (132) is installed at the air outlet of the blower (131), and the other end of the powder feeding pipe (132) is fixedly connected to the free end of the powder inlet pipe (22). One end of the return air pipe (133) is installed at the blower (131). At the return air inlet, the other end of the return air duct (133) is fixedly connected to the free end of the outlet air duct (24). The return air duct (133) and the outlet air duct (24), as well as the powder feeding duct (132) and the powder inlet duct (22), are all fixedly connected by connecting pipes (3). The powder outlet of the powder storage tank (121) is equipped with a powder outlet duct (123). The powder outlet duct (123) and the powder feeding duct (132) are installed at an angle. The angle of the powder outlet duct (123) makes the powder discharge direction different from that of the powder feeding duct, which is driven by the fan (131) inside the fan (131). The included angle of the feeding direction formed by the airflow is acute. A first butterfly valve (124) is installed on the powder outlet pipe (123). A second material level sensor (122) is installed on the powder storage tank (121). The first material level sensor (20) is electrically connected to the remote monitoring and control device (5). The remote monitoring and control device (5) is communicatively connected to the controller (11). The second material level sensor (122), the first butterfly valve (124), and the blower (131) are all electrically connected to the controller (11). A caster wheel (14) is also installed at the bottom of the box (1).

2. The powder supply system for metal 3D printing according to claim 1, characterized in that, The powder storage tank (121), powder delivery pipe (132) and return air pipe (133) are all equipped with pressure balancing pipes (4) for connecting with the external environment. The pressure balancing pipe (4) is equipped with a pinch valve (41) and the pinch valve (41) is electrically connected to the controller (11). The air outlet pipe (24) and powder inlet pipe (22) are both equipped with second butterfly valves (25) and the second butterfly valves (25) are electrically connected to the remote monitoring and control device (5).

3. The powder supply system for metal 3D printing according to claim 1, characterized in that, The housing (1) is also equipped with an inerting control device (171) electrically connected to the controller (11). An inerting gas inlet (172) is provided on the housing (1). The inerting gas inlet (172) is connected to the inerting control device (171). A washing gas inlet (173) is provided on the powder delivery pipe (132). A washing gas outlet (174) connected to an external filtration device is provided on the return air pipe (133). The inerting control device (171) is connected to the washing gas inlet (173). An oxygen content detector (28) and a temperature detection sensor (210) are installed in the powder loading tank (2). A pressure sensor (26) and a pressure relief valve (27) are installed on the powder loading tank (2). The oxygen content detector (28), temperature detection sensor (210), pressure sensor (26), and pressure relief valve (27) are all electrically connected to the remote monitoring and control device (5).

4. The powder supply system for metal 3D printing according to claim 1, characterized in that, The first material level sensor (20) includes a high material level sensor (201) and a low material level sensor (202). The low material level sensor (202) is close to the powder outlet of the upper powder tank (2), and the high material level sensor (201) is close to the powder inlet (21) of the upper tank. An alarm device (16) is also installed on the housing (1). The alarm device (16) is electrically connected to the controller (11).

5. The powder supply system for metal 3D printing according to claim 1, characterized in that, The filter element of the powder tank (2) is equipped with a differential pressure detector (211) for detecting the pressure difference between the two ends of the filter element. The differential pressure detector (211) is electrically connected to the remote monitoring and control device (5). The powder tank (2) is equipped with a backflush air manifold (29) above the filter element. The backflush air manifold (29) is connected to the inside of the powder tank (2) through a blowing pipe. The outlet of the blowing pipe is located in the upstream area of ​​the airflow channel of the filter element inside the powder tank (2). A backflush pulse valve is provided on the blowing pipe. The backflush pulse valve is electrically connected to the controller (11) to control the opening and closing of the backflush pulse valve through the controller (11).

6. The powder supply system for metal 3D printing according to claim 1, characterized in that, A manual butterfly valve (125) is also installed on the powder outlet pipe (123).

7. A control method for a powder supply system for metal 3D printing, characterized in that, The powder supply system applied to metal 3D printing according to any one of claims 1-6, the method comprising: In response to the powder delivery request, open the second butterfly valve; Based on the powder delivery request, the current state of the second level sensor (122) is obtained, and based on the current state of the second level sensor (122), it is determined whether the remaining amount of powder in the current powder storage tank (121) meets the powder delivery requirements. If the current state of the second level sensor (122) determines that the remaining amount of powder in the current powder storage tank (121) is equal to or lower than the preset minimum level, a powder replenishment signal is generated, and the alarm device (16) is controlled to issue an alarm to prompt the operator to replenish the powder. And according to the powder delivery request, the current oxygen content data detected by the oxygen content detection sensor is obtained, and based on the current oxygen content data, it is determined whether the current oxygen content of the current powder loading tank (2), powder delivery pipeline (132) and return air pipeline (133) is lower than the preset safety threshold. If, based on the current oxygen content data, it is determined that the current oxygen content of the powder feeding tank (2), powder delivery pipe (132), and return air pipe (133) is higher than or equal to the preset safety threshold, a gas scrubbing command is generated to control the gas scrubbing control device to open. When the current oxygen content data detected by the oxygen content detection sensor determines that the current oxygen content of the current powder tank (2), powder delivery pipeline (132) and return air pipeline (133) is lower than the preset safety threshold, a gas washing stop command is generated to control the gas washing control device to shut down. When the remaining amount of powder in the powder storage tank (121) meets the powder delivery requirements and the current oxygen content is lower than the preset safety threshold, the control fan (131), the first butterfly valve (124) and the second butterfly valve (25) are opened. After a first preset time, the first butterfly valve (124) is opened so that the fan (131) delivers the powder to the powder loading tank (2). In response to the request to stop powder feeding, the first butterfly valve (124) is closed, and the second butterfly valve (25) and the fan (131) are closed after a second preset time.

8. The control method for a powder supply system for metal 3D printing according to claim 7, characterized in that, After opening the first butterfly valve (124) after the first preset time period, the following is also included: Acquire dynamic level data from the first level sensor (20); When the amount of powder remaining in the powder storage tank (121) is lower than or equal to the preset minimum level, the processing stop command is generated based on the detection data of the first material level sensor (20). The first butterfly valve (124) is closed and the alarm device (16) is activated. After a second preset time, the blower (131) and the second butterfly valve (25) are closed. When the amount of powder remaining in the powder storage tank (121) is higher than the preset minimum level, based on the dynamic level data of the first level sensor (20), the powder level data of the second level sensor (122) is obtained. When the powder level data of the second material level sensor (122) is determined to be at or above the position of the high material level sensor (201), a pause processing command is generated and the first butterfly valve (124) is controlled to close. If, based on the dynamic level data of the second level sensor (122), it is determined that the powder in the current powder tank (2) remains at or above the position of the high level sensor (201) for a continuous second preset time, a stop processing command is generated, controlling the first butterfly valve (124) to close and controlling the alarm device (16) to sound an alarm, and after the second preset time, controlling the blower (131) and the second butterfly valve (25) to close; Based on the powder level data from the second level sensor (122), when the powder in the current powder tank (2) is lower than the position of the high level sensor (201) and / or at or below the position of the low level sensor (202), a powder feeding command is generated, and the first butterfly valve (124) is opened to continue feeding powder into the powder tank (2).

9. The control method for a powder supply system for metal 3D printing according to claim 7, characterized in that, After opening the first butterfly valve (124) after the first preset time period, the following is also included: The current temperature value detected by the temperature detection sensor (210) is obtained, and the current temperature value is compared with a preset safe temperature value. If the current temperature value is greater than or equal to the preset safe temperature value, a stop processing command is generated, controlling the first butterfly valve (124), the fan (131), and the second butterfly valve (25) to close and controlling the alarm device (16) to sound an alarm.

10. The control method for a powder supply system for metal 3D printing according to claim 7, characterized in that, After the second butterfly valve (25) and the blower (131) are closed after the second preset time, the following is also included: The clamp valve (41) is opened and then closed after a third preset time period.

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