A circulating toner supply method for a multi-functional SLM printer

Abstract

This application discloses a circulating toner supply method for a multi-functional SLM printer, comprising the following steps: when the toner level in the top toner tank is too low, the intermediate toner tank moves above the top toner tank via a moving mechanism, and the intermediate toner tank supplies toner to the top toner tank; when the level in the intermediate toner tank is too low, the main toner tank supplies toner to the intermediate toner tank; when the level in the main toner tank is too low or the level in the residual toner transfer tank is too high, a blower is activated to create an inert gas flow at a set pressure inside the air path toner conveying pipeline. The powder from the residual toner transfer tank or the replenishment tank enters the air path toner conveying pipeline under the action of the air flow and is conveyed to the cyclone separator for powder separation. The separated powder is then sent to the powder drying chamber for drying. The dried powder enters the ultrasonic sieving device for sieving, and the sieved powder enters the main toner tank. This application solves the problem of low efficiency in the existing technology of manually adding or transporting powder to complete the powder replenishment process of the printer.

Description

Technical Field

[0001] This application belongs to the field of additive manufacturing technology, specifically relating to a circulating powder supply method for a multifunctional SLM printing device. Background Technology

[0002] Additive manufacturing is an advanced manufacturing technology that uses data-driven, layer-by-layer material addition to form solid parts. Compared to traditional subtractive manufacturing, this technology can create lightweight, complex, and multi-material gradient components. It also features shorter process flows, less material waste, no need for molds, and support for personalized and customized processing. With the development of modern science, additive manufacturing technology has been applied to many fields, demonstrating excellent performance in areas such as cultural relic restoration and industrial manufacturing. However, the high costs of additive manufacturing printing materials and equipment operation and maintenance significantly limit the development of this technology.

[0003] Currently, most additive manufacturing (SLM) printing powder supply devices on the market have relatively simple functions, and most still rely on manual addition or handling of powder to complete the powder replenishment process. This is especially problematic when printing small parts, where only a small portion of the material is used in the printing process. Most of the powder is collected in a residual powder tank through the powder inlet, and then undergoes manual drying and sieving. This process has low automation and efficiency. Residual powder in the printing channel during material replacement leads to poor forming quality in subsequent prints, and the powder environment can also cause harm to the environment and human health. During SLM printing, the target part is generally in an inert gas environment. After each print, the inert gas in the forming chamber is discharged outdoors. This process causes printing powder to be released into the external environment along with the gas, affecting human health and the environment, and increasing equipment operating costs. Summary of the Invention

[0004] This application provides a circulating powder supply method for a multi-functional SLM printer, which solves the problem of low efficiency in the existing technology of manually adding or transporting powder to complete the powder replenishment process of the printer. At the same time, it realizes the recycling of inert gas and the circulating powder supply for multiple printers.

[0005] To achieve the above objectives, embodiments of the present invention provide a circulating toner supply method for a multi-functional SLM printer. The circulating toner supply method for a multi-functional SLM printer includes a residual toner transfer tank. The upper interface of the residual toner transfer tank is connected to the toner discharge port of the forming chamber inside the SLM printer through a ninth electric butterfly valve and a toner discharge pipe. The lower interface of the residual toner transfer tank is connected to a pneumatic toner conveying pipe through a tenth electric butterfly valve.

[0006] The outlet in the middle of the argon cylinder is connected to the SLM printing equipment via the Hth electric ball valve and the first argon delivery pipe;

[0007] The outlet at the bottom of the argon tank is connected to the blower inlet via a second argon delivery pipe, and the blower outlet is connected to the inlet of the gas powder delivery pipeline.

[0008] The air inlet of the cyclone separator is connected to the outlet of the air-powder conveying pipeline via the fifth shut-off valve; the powder outlet at the bottom of the cyclone separator is connected to the inlet of the powder drying chamber via the second electric butterfly valve and a connecting pipe, in which a photoelectric sensor is installed; the powder outlet at the bottom of the powder drying chamber is connected to the inlet of the ultrasonic sieving device via the third electric butterfly valve; the powder discharge port at the bottom of the ultrasonic sieving device is connected to the main powder storage tank via the fifth ninth electric butterfly valve and the sieving powder drop pipe; the waste discharge port at the bottom of the ultrasonic sieving device is connected to the waste collection chamber via the fourth third electric butterfly valve and the waste discharge pipe.

[0009] The outlet on one side of the airbag is connected to the inlet of the arch-breaking pipe through the C electric ball valve. The outlet of the arch-breaking pipe is connected to the inside of the main powder storage tank, the feed tank, the top powder storage tank and the transfer powder tank through multiple branch pipes. Electric ball valves are installed on each of the multiple branch pipes.

[0010] The transfer powder tank is installed via a moving mechanism. The transfer powder tank is vertically positioned between the main powder storage tank and the top powder storage tank. The top of the transfer powder tank is equipped with a funnel pipe that matches the bottom outlet of the main powder storage tank, and the bottom of the transfer powder tank is equipped with a telescopic connecting pipe that matches the top inlet of the top powder storage tank.

[0011] The toner tank is located on top of the SLM printer, and its outlet is connected to the inlet on top of the SLM printer.

[0012] The lower part of the replenishment tank is connected to the pneumatic powder conveying pipeline via the eleventh electric butterfly valve; the SLM printer assembly is installed on the pneumatic powder conveying pipeline;

[0013] The SLM printer operates in three modes: powder supply, pressure detection, and pipeline self-cleaning.

[0014] The powder replenishment process includes the following steps:

[0015] The argon cylinder is filled with gas into the forming chamber inside the SLM printing equipment through the first argon delivery pipe, and the SLM printing equipment starts to work.

[0016] When the material level in the top powder storage tank is too low, the transfer powder tank moves to the top of the top powder storage tank via a moving mechanism. After the telescopic connecting pipe at the bottom of the transfer powder tank is connected to the inlet at the top of the top powder storage tank, the transfer powder tank feeds powder to the top powder storage tank.

[0017] When the material level in the transfer powder tank is too low, the transfer powder tank is moved to the bottom of the main powder storage tank by the moving mechanism. After the funnel pipe at the top of the transfer powder tank is connected to the outlet at the bottom of the main powder storage tank, the main powder storage tank feeds powder to the transfer powder tank.

[0018] When the material level in the main powder storage tank is too low or the material level in the residual powder transfer tank is too high, the blower is started to create an inert gas flow at a set pressure inside the air path powder conveying pipeline. The powder in the residual powder transfer tank or the replenishment tank enters the air path powder conveying pipeline under the action of the air flow and is transported to the cyclone separator for powder separation. The separated powder is then sent to the powder drying chamber for drying. The dried powder enters the ultrasonic sieving device for sieving, and the sieved powder enters the main powder storage tank.

[0019] When the material level in the replenishment tank is too low, the staff will manually add powder.

[0020] When the material level in the residual material transfer powder tank is too low, start the blower. The blower will send the powder in the replenishment tank to the main powder storage tank, and then into the transfer powder tank, the top powder storage tank, and the SLM printing equipment in sequence before being sent to the residual material transfer powder tank.

[0021] In one possible implementation, the airbag is housed in a stainless steel shell, and the outlet on the other side of the airbag is connected to the air compressor inlet via a third electric ball valve. The air compressor is equipped with an air compressor pressure gauge, and the air compressor outlet is connected to the argon tank inlet via a fourth electric ball valve.

[0022] The pressure testing process includes the following steps:

[0023] When the pressure inside the airbag reaches the set value, the third electric ball valve is opened to start the air compressor. The air compressor compresses the argon gas inside the airbag. When the pressure inside the air compressor reaches the set value, the fourth electric ball valve is opened to input the compressed argon gas into the argon tank.

[0024] Staff manually added liquid argon through the inlet of the argon cylinder.

[0025] In one possible implementation, a first electric ball valve and a first pressure sensor are sequentially installed on the second argon gas delivery pipe; a Y-type filter and a flow rate sensor are sequentially installed on the gas-feeding powder pipeline between the lower interface of the residual powder transfer tank and the blower outlet; a second pressure sensor and an oxygen content monitor are sequentially installed on the gas-feeding powder pipeline on the side of the lower interface of the residual powder transfer tank away from the flow rate sensor.

[0026] The SLM printer unit is located on the air-toner pipeline between the lower interface of the residual toner transfer tank and the second pressure sensor. The lower part of the replenishment tank is connected to the air-toner pipeline via the eleventh electric butterfly valve on the side of the oxygen content detector away from the blower.

[0027] The powder drying chamber is equipped with humidity and temperature sensors; the drying cavity of the powder drying chamber is equipped with spiral stirring blades.

[0028] The outlet of the cyclone separator is connected to the inlet of the baffle dust collector, the outlet of the baffle dust collector is connected to the inlet of the bag filter, and the outlet of the bag filter is connected to the inlet of the three-way electric exhaust valve.

[0029] The upper part of the airbag is connected to the outlet of the first vertical pipe via a second electric ball valve, and the inlet of the first vertical pipe is connected to the outlet of the three-way electric exhaust valve.

[0030] When the material level in the main powder storage tank is too low, the first electric ball valve is opened, the ninth electric butterfly valve and the second electric butterfly valve are closed, the blower is started to form an airflow with a set pressure inside the air conveying pipeline, the three-way electric exhaust valve is opened, the flow velocity in the air conveying pipeline is detected by the flow velocity sensor, and the air pressure in the air conveying pipeline is detected by the first pressure sensor and the second pressure sensor. When the flow velocity is greater than the set value and the pressure difference is at the set threshold, the oxygen content monitor detects the oxygen content in the air conveying pipeline. When the oxygen content meets the standard, the three-way electric exhaust valve is closed and the tenth electric butterfly valve is opened.

[0031] When the flow rate is less than the set value and the pressure difference is greater than the set threshold, check if the Y-type filter is blocked. If the Y-type filter is not blocked, check if the pipeline is blocked.

[0032] The powder in the residual powder transfer tank enters the air-powder conveying pipeline under the action of airflow and is transported to the cyclone separator for powder separation. Photoelectric sensors detect the powder accumulation in the connecting pipeline. When powder accumulates, the second electric butterfly valve is opened and the third electric butterfly valve is closed. The separated powder is then sent to the powder drying chamber for drying. Humidity and temperature sensors detect the humidity and temperature in the powder drying chamber. When the humidity and temperature meet the requirements, the third electric butterfly valve is opened and the powder drying chamber is closed. The dried powder enters the ultrasonic sieving device for sieving, and the sieved powder enters the main powder storage tank.

[0033] In one possible implementation, the pipeline self-cleaning condition includes the following steps:

[0034] Close the fourth electric butterfly valve, connect the telescopic connecting pipe at the bottom of the transfer powder tank to the waste collection chamber through the pipeline, open the first electric ball valve, start the blower, and then blow the residual powder in the air-powder conveying pipeline, cyclone separator, powder drying chamber, ultrasonic sieving device, main powder storage tank, and transfer powder tank into the waste collection chamber.

[0035] When the material levels in the main powder storage tank, the top powder storage tank, and the intermediate powder storage tank show obvious stagnation, open the C electric ball valve and the electric ball valves on the branch pipelines of the main powder storage tank, the top powder storage tank, and the intermediate powder storage tank to perform a gas arch breaking operation.

[0036] In one possible implementation, when the blower is started, the first electric ball valve is opened, allowing argon gas from inside the argon tank to enter the blower and subsequently the gas powder conveying pipeline.

[0037] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0038] This invention provides a circulating powder supply method for a multifunctional SLM printing device. This invention solves the problems in the prior art where the powder supply device cannot achieve circulating powder supply and multiple devices can supply powder simultaneously. It also solves the problems of inert gas source recovery and utilization and powder pipeline and equipment self-cleaning. This invention effectively solves labor problems, improves equipment operational reliability, and allows for the secondary and effective recycling of argon gas in SLM printing equipment and pipelines. The equipment system can be adjusted in real time, effectively improving equipment control and achieving intelligent control. Adjustments using pressure gauges, pressure sensors, and air compressors prevent safety hazards caused by excessive pressure in the argon tank and gas bladder. Intelligent monitoring enables powder drying, sieving, gas-solid separation, and circulating supply, effectively saving costs. A checkerboard positioning system accurately positions the transfer powder tank within the working area. An IoT system enables interaction between the equipment and the control room, allowing real-time monitoring of equipment operation. The principle of gas arch breaking solves the problem of powder bridging in the powder supply tank, effectively improving powder utilization efficiency. The use of argon tanks and blowers effectively treats residual powder, reducing environmental pollution and the harm to humans from airborne powder. Attached Figure Description

[0039] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a schematic diagram of the circulating toner supply system for a multifunctional SLM printing device provided in an embodiment of the present invention.

[0041] Figure 2 This is a schematic diagram of the structure of the moving mechanism provided in an embodiment of the present invention.

[0042] Figure 3 This is a schematic diagram illustrating the principle of chessboard positioning provided in an embodiment of the present invention.

[0043] Figure 4 This is a schematic diagram of the structure of the powder transfer tank provided in an embodiment of the present invention.

[0044] Figure 5 This is a schematic diagram of the telescopic connecting pipe provided in an embodiment of the present invention.

[0045] Figure 6 This is a schematic diagram illustrating the principle of the circulating toner supply method for a multifunctional SLM printing device provided in an embodiment of the present invention.

[0046] Figure 7 This is a schematic diagram illustrating the principle of powder replenishment operation provided in an embodiment of the present invention.

[0047] Attached reference numerals: 1-Residual powder transfer tank; 2-Ninth electric butterfly valve; 3-Tenth electric butterfly valve; 4-Powder conveying pipeline; 5-Argon cylinder; 6-Hth electric ball valve; 7-Blower; 8-Cyclone separator; 9-Fifth shut-off valve; 10-Second electric butterfly valve; 11-Powder drying chamber; 12-Third electric butterfly valve; 13-Ultrasonic sieving device; 14-Fifth and Ninth electric butterfly valves; 15-Main powder storage tank; 16-Fourth and Third electric butterfly valves; 17-Waste collection compartment; 18-Airbag; 19-Cth electric ball valve; 20-Arch breaking pipeline; 21-Replenishment tank; 22-Top powder storage tank; 23-Transfer powder tank; 24-Function funnel pipeline; 25-Telescopic docking point. Pipe; 26-Eleventh electric butterfly valve; 27-SLM printer assembly; 28-Air compressor; 29-Fourth electric ball valve; 30-Sealing ring; 31-Seventh electric butterfly valve; 32-Upper connecting pipe; 33-Bellboard; 34-Lower connecting pipe; 35-Abutment ring; 36-Compression spring; 37-Support truss; 38-Longitudinal feed mechanism; 39-Transverse feed mechanism; 40-Baffle dust collector; 41-Bag dust collector; 42-Three-way electric exhaust valve; 43-First vertical pipe; 44-First electric ball valve; 45-First pressure sensor; 46-Y-type filter; 47-Flow rate sensor; 48-Second pressure sensor; 49-Oxygen content monitor. Detailed Implementation

[0048] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0049] In the description of the embodiments of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the embodiments of the present invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention according to the specific circumstances.

[0050] like Figures 1 to 7 As shown, the multifunctional SLM printing equipment circulating toner supply method provided in this embodiment of the invention includes a residual toner transfer tank 1. The upper interface of the residual toner transfer tank 1 is connected to the toner discharge port of the forming chamber inside the SLM printing equipment through a ninth electric butterfly valve 2 and a toner discharge pipe. The lower interface of the residual toner transfer tank 23 is connected to a tenth electric butterfly valve 3 and a pneumatic toner conveying pipe 4.

[0051] The outlet in the middle of the argon tank 5 is connected to the SLM printing equipment via the H electric ball valve 6 and the first argon delivery pipe.

[0052] The outlet at the bottom of the argon tank 5 is connected to the inlet of the blower 7 via the second argon delivery pipe, and the outlet of the blower 7 is connected to the inlet of the gas powder delivery pipe 4.

[0053] The air inlet of the cyclone separator 8 is connected to the outlet of the air-powder conveying pipe 4 via the fifth shut-off valve 9. The powder outlet at the bottom of the cyclone separator 8 is connected to the inlet of the powder drying chamber 11 via the second electric butterfly valve 10 and a connecting pipe, in which a photoelectric sensor is installed. The powder outlet at the bottom of the powder drying chamber 11 is connected to the inlet of the ultrasonic sieving device 13 via the third electric butterfly valve 12. The powder discharge port at the bottom of the ultrasonic sieving device 13 is connected to the main powder storage tank 15 via the fifth electric butterfly valve 14 and the sieved powder drop pipe. The waste discharge port at the bottom of the ultrasonic sieving device 13 is connected to the waste collection chamber 17 via the fourth electric butterfly valve 16 and the waste discharge pipe.

[0054] The outlet on one side of the airbag 18 is connected to the inlet of the arch-breaking pipe 20 through the C electric ball valve 19. The outlet of the arch-breaking pipe 20 is connected to the inside of the main powder storage tank 15, the feed tank 21, the top powder storage tank 22 and the intermediate powder storage tank 23 through multiple branch pipes. Each of the multiple branch pipes is equipped with an electric ball valve.

[0055] The transfer powder tank 23 is installed via a moving mechanism. The transfer powder tank 23 is vertically positioned between the main powder storage tank 15 and the top powder storage tank 22. The top of the transfer powder tank 23 is provided with a funnel pipe 24 for cooperating with the bottom outlet of the main powder storage tank 15, and the lower end of the transfer powder tank 23 is provided with a telescopic connecting pipe 25 for cooperating with the top inlet of the top powder storage tank 22.

[0056] The toner tank 22 is located on the top of the SLM printer, and the outlet of the toner tank 22 is connected to the inlet on the top of the SLM printer.

[0057] The lower part of the replenishment tank 21 is connected to the pneumatic toner supply pipe 4 via the eleventh electric butterfly valve 26. The SLM printer assembly 27 is mounted on the pneumatic toner supply pipe 4.

[0058] It should be noted that the residual toner transfer tank 1 is an internal collection device for storing residual toner after printing within the SLM printer, and is part of the SLM printer. The SLM printer group 27 and the SLM printer are printers of the same specifications, that is, the printer group consists of multiple SLM printers of the same specifications, all of which can be connected to the toner supply pipeline of the SLM printer. Each device in the SLM printer group 27 is equipped with a residual toner transfer tank, and the residual toner transfer tank of the SLM printer group 27 and the residual toner transfer tank 1 of the SLM printer are installed in the same way.

[0059] There are two residual toner transfer tanks 1, which are symmetrically arranged in the SLM printing equipment. Inert argon gas is used as a protective gas. After one printing cycle, the argon gas in the forming chamber will not be discharged to the outside. It is recovered by the gas bag 18 to prevent the printing powder from being discharged into the external environment with the gas, thereby affecting the environment and human health.

[0060] Argon gas tank 5 is equipped with pressure gauges and level gauges. The powder drying chamber 11 is equipped with mica heating elements.

[0061] In this embodiment, the airbag 18 is housed within a stainless steel casing. The outlet on the other side of the airbag 18 is connected to the inlet of the air compressor 28 via a third electric ball valve. The air compressor 28 is equipped with an air compressor pressure gauge. The outlet of the air compressor 28 is connected to the inlet of the argon tank 5 via a fourth electric ball valve 29. The airbag 18 is a commonly used airbag for pneumatic components, and a pressure gauge is installed inside it.

[0062] In this embodiment, the upper end of the funnel pipe 24 is a funnel section, and a sealing ring 30 is provided on the inner wall of the small opening end of the funnel section. A seventh electric butterfly valve 31 is provided at the lower part of the funnel pipe 24.

[0063] It should be noted that the funnel section facilitates the receipt of powder, and the sealing ring 30 is used to improve the sealing performance.

[0064] In this embodiment, the telescopic connecting pipe 25 includes an upper connecting pipe 32, a bellows pipe 33, and a lower connecting pipe 34 connected in sequence. Both the upper connecting pipe 32 and the lower connecting pipe 34 are fitted with abutment rings 35. The bellows pipe 33 is circumferentially provided with a plurality of compression springs 36. The two ends of the compression springs 36 are respectively connected to the abutment rings 35 of the upper connecting pipe 32 and the lower connecting pipe 34.

[0065] It should be noted that after the telescopic connecting pipe 25 and the top inlet of the powder storage tank 22 are fitted together, the bellows 33 and the compression spring 36 both contract, creating a certain pressure between the telescopic connecting pipe 25 and the top inlet of the powder storage tank 22, thereby improving the sealing performance.

[0066] In this embodiment, the moving mechanism includes a support truss 37, a longitudinal feeding mechanism 38, and a transverse feeding mechanism 39. The support truss 37 is fixedly installed, and the longitudinal feeding mechanism 38 is fixedly installed on both sides of the support truss 37. The two ends of the transverse feeding mechanism 39 are installed on the sliding ends of the longitudinal feeding mechanism 38, and the transfer powder tank 23 is installed on the sliding ends of the transverse feeding mechanism 39.

[0067] It should be noted that both the longitudinal feed mechanism 38 and the transverse feed mechanism 39 employ a nut and screw drive mechanism, thereby enabling the intermediate toner tank 23 to be adjusted at any position on the X and Y axes. This connection method not only allows the circulating toner supply system to supply powder to multiple machines but also reduces the vibration generated during powder supply, ensuring print quality. The intermediate toner tank 23 uses a more efficient checkerboard positioning method for positioning the main toner tank and the intermediate toner tank 23, which can quickly and accurately position the top toner storage tank 22 while reducing the computational load on the controller. The checkerboard positioning principle of this embodiment is as follows: the initial position of the main material tank is used as the origin to calibrate the working plane. The working plane is divided into X and Y directions according to the checkerboard pattern. The horizontal feeding mechanism 39 corresponds to the X direction, and similarly, the vertical feeding mechanism 38 corresponds to the Y direction. Through the control of the motor, the feeding mechanism feeds at a speed of 5cm / s in the X and Y directions each time. When the feeding mechanism approaches the SLM printing equipment or the main material tank as shown in the figure, the feeding speed is adjusted to 1mm / s by the stepper motor. That is, when the feeding mechanism approaches the target point in the X or Y direction, the approach distance is set to 1cm, and its feeding speed is slowed down. This is used to feed or replenish the powder storage tank 22 on the top of the machine or the main material tank.

[0068] In this embodiment, a third manual butterfly valve for manual powder addition is provided on the upper part of the feeding tank 21.

[0069] In this embodiment, the outlet of the cyclone separator 8 is connected to the inlet of the baffle dust collector 40, the outlet of the baffle dust collector 40 is connected to the inlet of the bag filter 41, and the outlet of the bag filter 41 is connected to the inlet of the three-way electric exhaust valve 42.

[0070] The upper part of the airbag 18 is connected to the outlet of the first vertical pipe 43 via a second electric ball valve, and the inlet of the first vertical pipe 43 is connected to the outlet of the three-way electric exhaust valve 42.

[0071] It should be noted that the gas discharged from the cyclone separator 8 is further recovered by the baffle dust collector 40 and the bag dust collector 41, and the separated gas enters the air bag 18.

[0072] In this embodiment, a humidity sensor and a temperature sensor are installed inside the powder drying chamber 11. Spiral stirring blades are installed inside the drying cavity of the powder drying chamber 11.

[0073] It should be noted that the spiral stirring blades further improve the drying efficiency of the powder drying chamber 11.

[0074] In this embodiment, a first electric ball valve 44 and a first pressure sensor 45 are sequentially installed on the second argon gas delivery pipe. A Y-type filter 46 and a flow rate sensor 47 are sequentially installed on the gas path powder delivery pipe 4 between the lower interface of the residual powder transfer tank 23 and the outlet of the blower 7. A second pressure sensor 48 and an oxygen content monitor 49 are sequentially installed on the side of the gas path powder delivery pipe 4 away from the flow rate sensor 47 at the lower interface of the residual powder transfer tank 23.

[0075] SLM printer assembly 27 is located on the air-toner pipeline 4 between the lower interface of the residual toner transfer tank 23 and the second pressure sensor 48. The lower part of the replenishment tank 21 is connected to the air-toner pipeline 4 via the eleventh electric butterfly valve 26 on the side of the oxygen content detector away from the blower 7.

[0076] In this embodiment, material level detection sensors are installed inside the main powder storage tank 15, the replenishment tank 21, the top powder storage tank 22, and the intermediate powder transfer tank 23.

[0077] The multifunctional SLM printer circulating powder supply method provided in this embodiment of the invention includes powder replenishment mode, pressure detection mode and pipeline self-cleaning mode when the SLM printer is working.

[0078] The powder replenishment process includes the following steps:

[0079] Open the H electric ball valve 6, and the argon tank 5 will be filled with gas into the forming chamber inside the SLM printing equipment through the first argon delivery pipe, and the SLM printing equipment will start working.

[0080] When the material level in the top powder storage tank 22 is too low, the transfer powder tank 23 moves to the top of the top powder storage tank 22 via a moving mechanism. After the telescopic connecting pipe 25 at the bottom of the transfer powder tank 23 is connected to the inlet at the top of the top powder storage tank 22, the transfer powder tank 23 feeds powder to the top powder storage tank 22.

[0081] When the material level in the transfer powder tank 23 is too low, the transfer powder tank 23 is moved to the bottom of the main powder storage tank 15 by the moving mechanism. After the funnel pipe 24 at the top of the transfer powder tank 23 is connected to the lower outlet of the main powder storage tank 15, the main powder storage tank 15 feeds powder to the transfer powder tank 23.

[0082] When the material level in the main powder storage tank 15 is too low or the material level in the residual powder transfer tank 1 is too high, the blower 7 is started to form an inert gas flow at a set pressure inside the air path powder conveying pipeline 4. The powder in the residual powder transfer tank 1 or the replenishment tank 21 enters the air path powder conveying pipeline 4 under the action of the air flow and is transported to the cyclone separator 8 to separate the powder. The separated powder is then sent to the powder drying chamber 11 for drying. The dried powder enters the ultrasonic sieving device 13 for sieving. The sieved powder enters the main powder storage tank 15.

[0083] When the material level in the replenishment tank 21 is too low, the staff manually add powder through the third zero manual butterfly valve.

[0084] When the material level in the residual material transfer powder tank 23 is too low, open the eleventh electric butterfly valve 26 and the first electric ball valve 44, start the blower 7, and the blower 7 will send the powder in the replenishment tank 21 to the main powder storage tank 15, and then sequentially enter the transfer powder tank 23, the top powder storage tank 22 and the SLM printing equipment before being sent to the residual material transfer powder tank 23.

[0085] In this embodiment, the airbag 18 is housed in a stainless steel shell. The outlet on the other side of the airbag 18 is connected to the inlet of the air compressor 28 through a third electric ball valve. An air compressor pressure gauge is installed on the air compressor 28. The outlet of the air compressor 28 is connected to the inlet of the argon tank 5 through a fourth electric ball valve 29.

[0086] The pressure testing process includes the following steps:

[0087] When the pressure inside the airbag 18 reaches the set value, the third electric ball valve is opened, and the air compressor 28 is started. The air compressor 28 compresses the argon gas inside the airbag 18. When the pressure inside the air compressor 28 reaches the set value, the fourth electric ball valve 29 is opened, and the compressed argon gas is input into the argon tank 5.

[0088] Staff manually added liquid argon through the inlet of argon tank 5.

[0089] In this embodiment, when the material level in the main powder storage tank 15 is too low, the first electric ball valve 44 is opened, the ninth electric butterfly valve 2 and the second electric butterfly valve 10 are closed, the blower 7 is started, and an airflow with a set pressure is formed inside the air-powder conveying pipeline 4. The three-way electric exhaust valve 42 is opened, and the flow velocity in the air-powder conveying pipeline 4 is detected by the flow velocity sensor 47. At the same time, the air pressure in the air-powder conveying pipeline 4 is detected by the first pressure sensor 45 and the second pressure sensor 48. When the flow velocity is greater than the set value and the pressure difference is at the set threshold, the oxygen content monitor 49 detects the oxygen content in the air-powder conveying pipeline 4. When the oxygen content meets the standard, the three-way electric exhaust valve 42 is closed and the tenth electric butterfly valve 3 is opened.

[0090] When the flow rate is less than the set value and the pressure difference is greater than the set threshold, check whether the Y-type filter 46 is blocked. If the Y-type filter 46 is not blocked, check whether the pipeline is blocked.

[0091] The powder in the residual powder transfer tank 1 enters the air-powder conveying pipeline 4 under the action of airflow and is transported to the cyclone separator 8 to separate the powder. The photoelectric sensor detects the powder accumulation in the connecting pipeline. When the powder accumulates, the second electric butterfly valve 10 is opened and the third electric butterfly valve 12 is closed. The separated powder is then sent to the powder drying chamber 11 for drying. The humidity sensor and temperature sensor detect the humidity and temperature in the powder drying chamber 11. When the humidity and temperature meet the requirements, the third electric butterfly valve 12 is opened and the powder drying chamber 11 is closed. The dried powder enters the ultrasonic sieving device 13 for sieving and the sieved powder enters the main powder storage tank 15.

[0092] In this embodiment, the pipeline self-cleaning mode includes the following steps:

[0093] Close the fourth electric butterfly valve 16, connect the telescopic connecting pipe 25 at the bottom of the transfer powder tank 23 to the waste collection chamber 17 through the pipeline, open the first electric ball valve 44, start the blower 7, and then blow the residual powder in the air-powder conveying pipeline 4, cyclone separator 8, powder drying chamber 11, ultrasonic sieving device 13, main powder storage tank 15, and transfer powder tank 23 into the waste collection chamber 17.

[0094] When the material levels in the main powder storage tank 15, the top powder storage tank 22, and the intermediate powder storage tank 23 show obvious stagnation, open the C electric ball valve 19 and the electric ball valves on the branch pipelines of the main powder storage tank 15, the top powder storage tank 22, and the intermediate powder storage tank 23 to perform a gas arch breaking operation.

[0095] It should be noted that the argon gas inside the expansion bladder 18 is introduced into the powder tank. When the powder supply is in operation, the powder bridges in each powder tank are broken, effectively solving the powder bridging phenomenon and improving the efficiency of equipment supply and powder circulation.

[0096] Both the argon tank 5 and the gas bladder 18 are equipped with pressure sensors. The signals measured by the pressure sensors are transmitted to the control room through the DTU module. When the pressure is too high, the display screen in the control room will show the pressure information, and at the same time, the alarm will sound to remind the staff to release the gas in the argon tank 5 or the system will compress the excess argon into the argon tank 5 through the air compressor 28, which further improves the utilization rate of argon and effectively solves the safety hazards caused by excessive pressure in the tank.

[0097] A Y-type filter 46 for gas-solid separation is installed on the air-powder conveying pipe 4. At the same time, a pipe bending process is performed at the location where the Y-type filter 46 is installed, making it more difficult for powder to enter the blower 7, thus preventing damage to the blower 7 due to powder blockage.

[0098] When the flow velocity in the pipeline is lower than the set threshold or the difference between the pressure sensors at both ends is higher than the specified difference, the alarm in the control room will sound to remind staff to check for blockages in the filter element or other parts of the pipeline.

[0099] Argon tank 5 is equipped with a level gauge. The level gauge sends a signal to the control room via a PLC controller. When the level is low, the controller receives the signal, and the display screen in the control room shows that the level is low. At the same time, the alarm sounds to remind the driver to add liquid argon.

[0100] The cyclone separator 8, powder drying chamber 11, ultrasonic sieving device 13, and main powder storage tank 15 are vertically integrated on the truss via connecting pipes. Each interface has valves of different specifications, facilitating equipment maintenance and reducing space usage. The powder drying chamber 11 is equipped with spiral stirring blades, which to some extent circulate the powder along the blade tracks, ensuring uniform heating, reducing drying time, and improving drying efficiency. Photoelectric sensors are used to detect powder accumulation within the connecting pipes.

[0101] When it is necessary to change to other printing metal powders, the original pipelines need to be cleaned to prevent the new printing material from being contaminated. Therefore, when the system starts running, the control interface will remind the staff whether to end the operation. When the staff selects to end the operation, the control interface will remind the staff whether to self-clean the pipeline. When the staff confirms self-cleaning of the pipeline, because the forming time of powder bridging is random and uncertain, for the arch breaking operation, when the material level detection shows obvious stagnation, open the electric ball valves on the branch pipelines of the main powder storage tank 15, the top powder storage tank 22, and the intermediate powder tank 23 to perform a gas arch breaking.

[0102] In this embodiment, when the blower 7 is started, the first electric ball valve 44 is opened, allowing the argon gas inside the argon tank 5 to enter the blower 7 and then enter the gas powder conveying pipeline 4.

[0103] This invention solves the problems of existing powder supply devices not being able to achieve cyclic powder supply and simultaneous powder supply from multiple devices. It also solves the problems of inert gas source recovery and self-cleaning of powder pipelines and equipment. This invention effectively solves labor issues, improves equipment operational reliability, and allows for the effective secondary recovery and reuse of argon gas in SLM printing equipment and pipelines. The equipment system can be adjusted in real time, effectively improving equipment control and achieving intelligent control. Adjustments using pressure gauges, pressure sensors, and air compressor 28 avoid safety hazards caused by excessive pressure in argon tank 5 and air bladder 18. Intelligent monitoring enables powder drying, sieving, gas-solid separation, and cyclic supply, effectively saving costs. A checkerboard positioning system accurately positions the transfer powder tank 23 within the working area. An IoT system enables interaction between the equipment and the control room, allowing real-time monitoring of equipment operation. The principle of gas arch breaking solves the problem of powder bridging within the powder supply tank, effectively improving powder utilization efficiency. The use of argon gas tank 5 and blower 7 can effectively treat residual powder, reducing environmental pollution and the harm to the human body from powder floating in the air.

[0104] The control methods involved in this embodiment, such as DTU modules, PLC controllers, and chessboard positioning methods, are all existing technologies. This embodiment will not elaborate further on the specific control principles.

[0105] In this embodiment, it will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of the equivalents of the claims be included within the present invention.

Claims

1. A circulating toner supply method for a multi-functional SLM printer, wherein the circulating toner supply method for the multi-functional SLM printer includes a residual toner transfer tank (1), the upper interface of the residual toner transfer tank (1) is connected to the toner discharge port of the forming chamber inside the SLM printer through a ninth electric butterfly valve (2) and a toner discharge pipe, and the lower interface of the residual toner transfer tank (23) is connected through a tenth electric butterfly valve (3) and a pneumatic toner conveying pipe (4); The outlet in the middle of the argon tank (5) is connected to the SLM printing equipment through the Hth electric ball valve (6) and the first argon delivery pipe; The outlet at the bottom of the argon tank (5) is connected to the inlet of the blower (7) through the second argon delivery pipe, and the outlet of the blower (7) is connected to the inlet of the gas powder conveying pipe (4); The air inlet of the cyclone separator (8) is connected to the outlet of the air-powder conveying pipe (4) through the fifth shut-off valve (9); the powder outlet at the bottom of the cyclone separator (8) is connected to the inlet of the powder drying chamber (11) through the second electric butterfly valve (10) and the connecting pipe, and a photoelectric sensor is installed in the connecting pipe; the powder outlet at the bottom of the powder drying chamber (11) is connected to the inlet of the ultrasonic sieving device (13) through the third electric butterfly valve (12), and the powder discharge port at the bottom of the ultrasonic sieving device (13) is connected to the main powder storage tank (15) through the fifth electric butterfly valve (14) and the sieving powder drop pipe; the waste discharge port at the bottom of the ultrasonic sieving device (13) is connected to the waste collection chamber (17) through the fourth electric butterfly valve (16) and the waste discharge pipe. The outlet of the airbag (18) is connected to the inlet of the arch-breaking pipe (20) through the C electric ball valve (19). The outlet of the arch-breaking pipe (20) is connected to the inside of the main powder storage tank (15), the feed tank (21), the top powder storage tank (22) and the transfer powder tank (23) through multiple branch pipes. Each branch pipe is equipped with an electric ball valve. The transfer powder tank (23) is installed via a moving mechanism. The transfer powder tank (23) is vertically positioned between the main powder storage tank (15) and the top powder storage tank (22). The top of the transfer powder tank (23) is provided with a funnel pipe (24) for cooperating with the bottom outlet of the main powder storage tank (15). The lower end of the transfer powder tank (23) is provided with a telescopic connecting pipe (25) for cooperating with the top inlet of the top powder storage tank (22). The toner tank (22) is located on the top of the SLM printer, and the outlet of the toner tank (22) is connected to the inlet on the top of the SLM printer. The lower part of the feed tank (21) is connected to the air-powder conveying pipeline (4) via the eleventh electric butterfly valve (26); Its features are, The SLM printer operates in three modes: powder supply, pressure detection, and pipeline self-cleaning. The powder replenishment process includes the following steps: Argon cylinder (5) is filled with gas into the forming chamber inside the SLM printing equipment through the first argon delivery pipe, and the SLM printing equipment starts to work; When the material level in the top powder storage tank (22) is too low, the transfer powder tank (23) moves to the top powder storage tank (22) via a moving mechanism. After the telescopic connecting pipe (25) at the bottom of the transfer powder tank (23) is connected to the inlet at the top of the top powder storage tank (22), the transfer powder tank (23) feeds powder to the top powder storage tank (22). When the material level in the transfer powder tank (23) is too low, the transfer powder tank (23) moves to the bottom of the main powder storage tank (15) through the moving mechanism. After the funnel pipe (24) at the top of the transfer powder tank (23) is connected to the outlet at the bottom of the main powder storage tank (15), the main powder storage tank (15) feeds powder to the transfer powder tank (23). When the material level in the main powder storage tank (15) is too low or the material level in the residual powder transfer tank (1) is too high, the blower (7) is started to form an inert gas flow with a set pressure inside the air-powder conveying pipeline (4). The powder in the residual powder transfer tank (1) or the replenishment tank (21) enters the air-powder conveying pipeline (4) under the action of the air flow and is conveyed to the cyclone separator (8) to separate the powder. The separated powder is then sent to the powder drying chamber (11) for drying. The dried powder enters the ultrasonic sieving device (13) for sieving. The sieved powder enters the main powder storage tank (15). When the material level in the replenishment tank (21) is too low, the staff should manually add powder. When the material level in the residual material transfer powder tank (23) is too low, the blower (7) is started. The blower (7) sends the powder in the replenishment tank (21) to the main powder storage tank (15), and then sequentially enters the transfer powder tank (23), the top powder storage tank (22), and the SLM printing equipment before being sent to the residual material transfer powder tank (23).

2. The circulating toner supply method for a multifunctional SLM printer according to claim 1, characterized in that: The airbag (18) is housed in a stainless steel shell. The outlet of the airbag (18) on the other side is connected to the inlet of the air compressor (28) through the third electric ball valve. The air compressor (28) is equipped with an air compressor pressure gauge. The outlet of the air compressor (28) is connected to the inlet of the argon tank (5) through the fourth electric ball valve (29). The pressure testing process includes the following steps: When the pressure inside the airbag (18) reaches the set value, the third electric ball valve is opened and the air compressor (28) is started. The air compressor (28) compresses the argon gas inside the airbag (18). When the pressure inside the air compressor (28) reaches the set value, the fourth electric ball valve (29) is opened and the compressed argon gas is input into the argon tank (5). Staff manually add liquid argon through the inlet of the argon cylinder (5).

3. The circulating toner supply method for a multifunctional SLM printer according to claim 2, characterized in that: The second argon gas delivery pipe is sequentially equipped with a first electric ball valve (44) and a first pressure sensor (45). The gas path powder delivery pipe (4) is sequentially equipped with a Y-type filter (46) and a flow rate sensor (47) on the pipeline between the lower interface of the residual powder transfer tank (23) and the outlet of the blower (7). The gas path powder delivery pipe (4) is sequentially equipped with a second pressure sensor (48) and an oxygen content monitor (49) on the pipeline on the side of the lower interface of the residual powder transfer tank (23) away from the flow rate sensor (47). The lower part of the feed tank (21) is connected to the air-powder conveying pipeline (4) via the eleventh electric butterfly valve (26), and is located on the side of the oxygen content detector away from the blower (7); The powder drying chamber (11) is equipped with a humidity sensor and a temperature sensor; the drying chamber (11) is equipped with a spiral stirring blade. The outlet of the cyclone separator (8) is connected to the inlet of the baffle dust collector (40), the outlet of the baffle dust collector (40) is connected to the inlet of the bag dust collector (41), and the outlet of the bag dust collector (41) is connected to the inlet of the three-way electric exhaust valve (42). The upper part of the airbag (18) is connected to the outlet of the first vertical pipe (43) via the second electric ball valve, and the inlet of the first vertical pipe (43) is connected to the outlet of the three-way electric exhaust valve (42); When the material level in the main powder storage tank (15) is too low, the first electric ball valve (44) is opened, the ninth electric butterfly valve (2) and the second electric butterfly valve (10) are closed, the blower (7) is started, and the airflow with a set pressure is formed inside the air-powder conveying pipeline (4). The three-way electric exhaust valve (42) is opened, and the flow velocity in the air-powder conveying pipeline (4) is detected by the flow velocity sensor (47). At the same time, the air pressure in the air-powder conveying pipeline (4) is detected by the first pressure sensor (45) and the second pressure sensor (48). When the flow velocity is greater than the set value and the pressure difference is at the set threshold, the oxygen content monitor (49) detects the oxygen content in the air-powder conveying pipeline (4). When the oxygen content meets the standard, the three-way electric exhaust valve (42) is closed and the tenth electric butterfly valve (3) is opened. When the flow rate is less than the set value and the pressure difference is greater than the set threshold, check whether the Y-type filter (46) is blocked. If the Y-type filter (46) is not blocked, check whether the pipeline is blocked. The powder in the residual powder transfer tank (1) enters the air path powder conveying pipeline (4) under the action of airflow and is transported to the cyclone separator (8) to separate the powder. The photoelectric sensor detects the powder accumulation in the connecting pipeline. When the powder accumulates, the second electric butterfly valve (10) is opened and the third electric butterfly valve (12) is closed. The separated powder is then sent to the powder drying chamber (11) for drying. The humidity sensor and temperature sensor detect the humidity and temperature in the powder drying chamber (11). When the humidity and temperature meet the requirements, the third electric butterfly valve (12) is opened and the powder drying chamber (11) is closed. The dried powder enters the ultrasonic sieving device (13) for sieving. The sieved powder enters the main powder storage tank (15).

4. The circulating toner supply method for a multifunctional SLM printer according to claim 3, characterized in that: The self-cleaning operation of pipelines includes the following steps: Close the fourth electric butterfly valve (16), connect the telescopic connecting pipe (25) at the bottom of the transfer powder tank (23) to the waste collection chamber (17) through the pipeline, open the first electric ball valve (44), start the blower (7), and then blow the residual powder in the air-powder conveying pipeline (4), cyclone separator (8), powder drying chamber (11), ultrasonic sieving device (13), main powder storage tank (15), and transfer powder tank (23) into the waste collection chamber (17); When the material levels in the main powder storage tank (15), the top powder storage tank (22), and the intermediate powder storage tank (23) show obvious stagnation, open the C electric ball valve (19) and the electric ball valves on the branch pipelines of the main powder storage tank (15), the top powder storage tank (22), and the intermediate powder storage tank (23) to perform a gas arch breaking.

5. The circulating toner supply method for a multi-functional SLM printer according to claim 4, characterized in that: When the blower (7) is started, the first electric ball valve (44) is opened, allowing the argon gas inside the argon tank (5) to enter the blower (7) and then enter the gas powder conveying pipeline (4).

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