Powder recovery circulation system and control method of selective laser sintering equipment

Abstract

The present invention relates to a powder recovery circulation system of a selective laser sintering device and a control method thereof. The powder recovery circulation system of the selective laser sintering device comprises a power device, a separation tank, a storage tank, a conveying tank and a first recovery tank, the discharge end of the separation tank is connected to the feed end of the storage tank; the discharge end of the storage tank is connected to the feed end of the conveying tank, the exhaust end of the conveying tank is connected to the feed end of the separation tank; the discharge end of the first recovery tank is connected to the feed end of the separation tank; the exhaust port of the power device is connected to the discharge end of the storage tank and the discharge end of the first recovery tank, and the exhaust port is connected to the exhaust end of the separation tank. The powder recovery circulation system of the selective laser sintering device provided by the present invention and the control method thereof, under the action of the power device, causes the powder to circulate between the storage tank, the conveying tank and the separation tank and to circulate between the first recovery tank and the separation tank, so that the powder recovery operation is simple, the labor intensity is low and the safety is good.

Description

Technical Field

[0001] The present invention relates to the technical field of additive manufacturing, and in particular to a powder recovery circulation system of a selective laser sintering device and a control method thereof. Background Art

[0002] Additive Manufacturing (AM) is an advanced manufacturing technology with the advantages of digital manufacturing, high flexibility and adaptability, direct CAD model drive, fast speed, and rich and diverse material types. Among them, Selective Laser Melting (SLM) is one of the additive manufacturing technologies that has developed rapidly in recent years. It uses powder materials as raw materials and uses lasers to scan the cross-section of three-dimensional entities layer by layer to complete prototype manufacturing. It is not limited by the complexity of the shape, does not require any tooling, and has a wide range of applications.

[0003] The basic process of the selective laser melting process includes powder supply and powder recovery. At present, powder supply and powder recovery are generally operated manually, and the operator manually disassembles and replaces the powder supply and recovery tanks during the sintering process.

[0004] However, the manual working method is not only cumbersome, but also requires the operator to pay real-time attention to the powder usage status and replace the empty supply tank and the full recovery tank in time. At the same time, there are also major safety hazards, such as powder leakage and personal safety of the operator during the process of lifting the tank. Summary of the invention

[0005] Based on this, it is necessary to provide a powder recovery circulation system and control method for a selective laser sintering equipment that is simple to operate, has low labor intensity and is safe, in view of the problems that powder supply and powder recovery in the existing selective laser melting process are both manual, which have complicated operations, high labor intensity and great safety hazards.

[0006] A powder recovery circulation system for a selective laser sintering device, comprising a power device, a separation tank, a storage tank, a conveying tank of the selective laser sintering device, and a first recovery tank connected to a working chamber of the selective laser sintering device;

[0007] The discharge end of the separation tank is operably connected to the feed end of the storage tank;

[0008] The discharge end of the storage tank is operably connected to the feed end of the conveying tank, and the exhaust end of the conveying tank is operably connected to the feed end of the separation tank;

[0009] The discharge end of the first recovery tank is operably connected to the feed end of the separation tank;

[0010] The power device comprises an air suction port and an exhaust port, wherein the exhaust port is operably connected to a discharge end of the storage tank and a discharge end of the first recovery tank, and the air suction port is connected to an exhaust end of the separation tank.

[0011] In one embodiment, the powder recovery circulation system further includes a powder post-processing platform and a second recovery tank;

[0012] The powder post-processing platform also has a discharge port, which is connected to the feed end of the second recovery tank. The discharge end of the second recovery tank is operably connected to the feed end of the separation tank. The exhaust port of the power device is operably connected to the discharge end of the second recovery tank.

[0013] In one embodiment, the powder post-processing platform has an air inlet and a powder suction port separated from the discharge port, the powder suction port is operably connected to the feed end of the separation tank, and the exhaust port of the power device is operably connected to the air inlet.

[0014] In one embodiment, the powder recovery circulation system is a closed powder recovery circulation system, and the powder recovery circulation system is filled with inert gas.

[0015] In one embodiment, the powder recovery circulation system further includes an oxygen detection sensor, and the oxygen detection sensor is used to detect the oxygen content in the powder recovery circulation system.

[0016] In one embodiment, the discharge end of the storage tank and the discharge end of the first recovery tank are both provided with a pulse stop valve, and the pulse stop valve is used to adjust the discharge volume and discharge speed of the discharge end of the storage tank and the discharge end of the first recovery tank.

[0017] In one embodiment, the powder recovery circulation system further includes a vibrating screen, which is disposed between the separation tank and the storage tank, and is used to screen the powder discharged from the discharge end of the separation tank and discharge it into the storage tank.

[0018] In one embodiment, the selective laser sintering equipment includes multiple devices, and the feed end of the conveying tank of each of the selective laser sintering devices is operably connected to the discharge end of the storage tank, the exhaust end of the conveying tank is operably connected to the feed end of the separation tank, and the discharge end of the first recovery tank is operably connected to the feed end of the separation tank.

[0019] A control method for a powder recovery circulation system of the selective laser sintering device as described above comprises the steps of:

[0020] Detecting the powder remaining amount in the conveying tank, and when the powder remaining amount in the conveying tank is lower than a first preset remaining amount, controlling the power device to start, the discharge end of the storage tank to open, and the exhaust end of the conveying tank to open;

[0021] Detecting the powder remaining amount in the storage tank, and when the powder remaining amount in the storage tank is lower than a second preset remaining amount, controlling the power device to stop, the discharge end of the storage tank to close, and the exhaust end of the conveying tank to close;

[0022] Detecting the powder remaining amount in the first recovery tank, and when the powder remaining amount in the first recovery tank is higher than a third preset remaining amount, controlling the power device to start and the discharge end of the first recovery tank to open; and when the powder remaining amount in the first recovery tank is lower than a fourth preset remaining amount, controlling the power device to stop and the discharge end of the first recovery tank to close;

[0023] Detect the powder residue in the separation tank. When the powder residue in the separation tank is higher than the fifth preset residue, control the discharge end of the separation tank to open and the feed end of the storage tank to open. When the powder residue in the separation tank is lower than the sixth preset residue or the powder residue in the storage tank is higher than the seventh preset residue, control the discharge end of the separation tank to close and the feed end of the storage tank to close.

[0024] In one embodiment, the powder recovery circulation system is a closed powder recovery circulation system, inert gas is filled in the powder recovery circulation system, and the powder recovery circulation system further includes an oxygen detection sensor, and the oxygen detection sensor is used to detect the oxygen content in the powder recovery circulation system;

[0025] The control method of the powder recovery circulation system further comprises the steps of:

[0026] Controlling the oxygen detection sensor to detect the oxygen content in the powder recovery circulation system;

[0027] When the oxygen content detected by the oxygen detection sensor is higher than a preset oxygen content value, the inert gas content in the powder recovery circulation system is adjusted to make the oxygen content in the powder recovery circulation system lower than the preset oxygen content value.

[0028] The powder recovery circulation system and control method of the above-mentioned selective laser sintering equipment, under the action of the power device, makes the powder circulate between the storage tank, the conveying tank and the separation tank and between the first recovery tank and the separation tank so that the powder can be recovered. Therefore, the operation of the powder recovery circulation system is simple, the labor intensity is low and the safety is good. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1Schematic diagram of the structure of a powder recovery circulation system of a selective laser sintering device in one embodiment of the present invention. DETAILED DESCRIPTION

[0030] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. Preferred embodiments of the present invention are provided in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0032] When describing positional relationships, unless otherwise specified, when an element is referred to as being "on" another element, it can be directly on the other element or there can be an intermediate element. It is also understood that when an element is referred to as being "between" two elements, it can be the only one between the two elements, or there can be one or more intermediate elements.

[0033] In the case of using “including”, “having”, and “comprising” described herein, another component may be added unless a clear limiting term such as “only”, “consisting of”, etc. is used. Unless mentioned otherwise, a term in the singular form may include a plural form and should not be understood as being one in number.

[0034] It should also be understood that when interpreting an element, even if not explicitly described, the element is interpreted as including a range of error, which should be within the acceptable deviation range of the specific value determined by those skilled in the art. For example, "approximately", "approximately" or "substantially" can mean within one or more standard deviations, which are not limited here.

[0035] In addition, the drawings are not drawn to a 1:1 scale, and the relative sizes of the elements in the drawings are drawn only as examples and not necessarily according to the true scale.

[0036] Figure 1 The figure shows a schematic diagram of the structure of the powder recovery circulation system of the selective laser sintering equipment in one embodiment of the present invention. For the convenience of description, the figure only shows the structure related to the embodiment of the present invention.

[0037] Referring to the drawings, a powder recovery circulation system 100 of a selective laser sintering device according to an embodiment of the present invention comprises a power device 10, a separation tank 20, a storage tank 30, a conveying tank 40 of the selective laser sintering device, and a first recovery tank 50 connected to a working chamber of the selective laser sintering device.

[0038] The discharge end of the separation tank 20 is operably connected to the feed end of the storage tank 30 .

[0039] The discharge end of the storage tank 30 is operably connected to the feed end of the conveying tank 40, and the exhaust end of the conveying tank 40 is operably connected to the feed end of the separation tank 20. When the residual powder in the conveying tank 40 is insufficient, the powder in the storage tank 30 can be transported to the conveying tank 40 to achieve the recovery and reuse of the powder. Specifically, the conveying tank 40 is provided with a separation device for separating gas and powder, and more specifically, the separation device is a cyclone separator, which can initially filter out large particles of powder and discharge the large particles of powder into the conveying tank 40, while the small particles of powder are transported to the separation tank 20 through the exhaust end for filtration.

[0040] It should be understood that the discharge end of the conveying tank 40 is connected to the powder supply mechanism of the selective laser sintering device to ensure timely material transportation to the selective laser sintering device.

[0041] The discharge end of the first recovery tank 50 is operably connected to the feed end of the separation tank 20. The first recovery tank 50 is connected to the working chamber of the selective laser sintering device and is used to recover the residual powder in the working chamber.

[0042] The power device 10 includes an air suction port 11 and an air exhaust port 12. The air exhaust port 12 is operably connected to the discharge end of the storage tank 30 and the discharge end of the first recovery tank 50. The air suction port 11 is connected to the exhaust end of the separation tank 20. Under the action of the power device 10, the powder discharged from the discharge end of the storage tank 30 can be transported to the conveying tank 40 under positive pressure, and then transported to the separation tank 20 through the conveying tank 40. The powder discharged from the discharge end of the first recovery tank 50 can also be transported to the separation tank 20 under positive pressure, and the clean gas discharged from the exhaust end of the separation tank 20 is absorbed and reused by the air suction port 11 of the power device 10. It should be understood that the pressure of the air suction port 11 and the air exhaust port 12 of the power device 10 are adjustable. Preferably, the power device 10 can generate a larger positive pressure pushing capacity at the exhaust port 12, and a smaller negative pressure adsorption capacity at the air suction port 11. In this way, the powder is conveyed faster under positive pressure, which improves the recovery efficiency of the powder recovery circulation system 100.

[0043] It should be understood that a filter is provided inside the separation tank 20, which can filter the powder entering from the feed end of the separation tank 20 to ensure that clean gas is discharged from the exhaust end of the separation tank 20 to the exhaust port 11 of the power device 10 and reused.

[0044] It should also be understood that those skilled in the art should know that the various connecting components should be connected using pipelines.

[0045] Thus, the powder recovery circulation system 100 of the selective laser sintering equipment of the present invention can, under the action of the power device 10, make the powder circulate between the storage tank 30, the conveying tank 40 and the separation tank 20 and between the first recovery tank 50 and the separation tank 20, so that the powder can be recovered, thus making the powder recovery operation simple, labor-intensive and safe. In addition, the powder recovery circulation system 100 of the present invention uses only one power device 10, which can realize the transportation and recovery requirements of multiple pipelines, greatly saving the cost of powder circulation.

[0046] In some embodiments, the powder recovery circulation system 100 includes a plurality of high-level level gauges 60, a plurality of low-level level gauges 65, and a plurality of stop valves 70. Specifically, a high-level level gauge 60 and a low-level level gauge 65 are provided on the separation tank 20, a stop valve 70 is provided at the discharge end of the separation tank 20, a high-level level gauge 60 and a low-level level gauge 65 are provided on the storage tank 30, a stop valve 70 is provided at the discharge end of the storage tank 30, and a stop valve 70 is also provided on the pipe connecting the exhaust port 12 of the power device 10 and the discharge end of the storage tank 30, a high-level level gauge 60 and a low-level level gauge 65 are provided on the first recovery tank 50, a stop valve 70 is provided at the discharge end of the first recovery tank 50, and a stop valve 70 is also provided on the pipe connecting the exhaust port 12 of the power device 10 and the discharge end of the first recovery tank 50. In this way, the high level meter 60 and the low level meter 65 can measure whether the powder remaining in the tank reaches the preset high value or the preset low value, and by opening or closing the stop valve 70, the communication between the components can be operably opened or closed.

[0047] Furthermore, the stop valves 70 provided at the discharge end of the storage tank 30 and the discharge end of the first recovery tank 50 are both pulse stop valves, which are used to adjust the discharge amount and discharge speed of the discharge end of the storage tank 30 and the discharge end of the first recovery tank 50. Since the lower end of the discharge end of the storage tank 30 and the lower end of the discharge end of the first recovery tank 50 are located at the intersection of three pipelines, once powder accumulation occurs, it is easy to cause the powder recovery circulation system 100 to malfunction or even be damaged, so the pulse stop valve can effectively control the discharge amount and discharge speed to avoid malfunctions.

[0048] In an embodiment of the present invention, the powder recovery circulation system 100 may include a controller, which is electrically connected to the plurality of high-level level gauges 60, the plurality of low-level level gauges 65, and the plurality of stop valves 70 to control the communication relationship between the components. In this way, the automatic operation of the powder recovery circulation system 100 can be realized, further avoiding the cumbersome process of manual operation and the hidden dangers of personal safety and environmental safety.

[0049] In some embodiments, the powder recovery circulation system 100 further includes a powder post-processing platform 75 and a second recovery tank 80. The powder post-processing platform 75 has a discharge port, which is connected to the feed end of the second recovery tank 80. The discharge end of the second recovery tank 80 is operably connected to the feed end of the separation tank 20, and the exhaust port 12 of the power device 10 is operably connected to the discharge end of the second recovery tank 80. In this way, the powder of the powder post-processing platform 75 can be recovered by the second recovery tank 80, thereby improving the recovery capacity of the powder recovery circulation system 100.

[0050] Furthermore, the powder post-processing platform 75 also has an air inlet 751 and a powder suction port 752 separated from the discharge port, the powder suction port 752 is operably connected to the feed end of the separation tank 20, and the exhaust port 12 of the power device 10 is operably connected to the air inlet 751. When the powder post-processing platform 75 is used for powder post-processing, most of the powder will be recycled to the second recovery tank 80 through the discharge port, and a small amount of powder remaining on the surface of the workpiece can be adsorbed into the separation tank 20 by the power device 10 using the powder suction port 752. In this way, the powder recovery amount can be increased.

[0051] In the existing powder post-processing, an external negative pressure adsorption device is generally used to handle the large amount of powder remaining after sintering. Although the negative pressure adsorption method can complete the powder transfer more conveniently, its working principle has inherent defects. For example, the negative pressure adsorption method can only be applied to open-loop or semi-open-loop working environments. In the 3D printing industry, many important materials, such as titanium alloys, pure titanium, aluminum alloys, etc., require an extremely low oxygen content environment during the transportation process to ensure the safety of equipment and personnel, and the negative pressure adsorption method cannot ensure that the oxygen content inside the conveying system meets the use requirements of these highly active metal materials. In addition, a small negative pressure source can only adapt to the powder transportation of a single location, and the powder transportation of multiple locations requires multiple negative pressure sources in parallel, which significantly increases the cost.

[0052] In the embodiment of the present invention, the powder recovery circulation system 100 is a closed powder recovery circulation system, and an inert gas is filled in the powder recovery circulation system 100. Since the power device 10 realizes the recycling of gas, the powder recovery circulation system 100 can be closed. In this way, the powder recovery circulation system 100 is filled with inert gas, which can better meet the circulation requirements of various types of powders including various active metals.

[0053] Furthermore, the powder recovery circulation system 100 also includes an exhaust valve disposed on the exhaust end side of the separation tank 20 and a pressure sensor 85 for detecting the pressure inside the powder recovery circulation system 100. Specifically, the pressure sensor 85 can be disposed on the separation tank 20, and the exhaust valve is disposed at the exhaust end of the separation tank 20 to eliminate interference from powder. The pressure sensor 85 and the exhaust valve are used to monitor and discharge excess pressure inside the powder recovery circulation system 100 to ensure the normal operation of the powder recovery circulation system 100 and prevent the powder recovery circulation system 100 from being damaged by overpressure.

[0054] In some embodiments, the powder recovery circulation system 100 further includes an oxygen detection sensor 90, which is used to detect the oxygen content in the powder recovery circulation system 100. In this way, it can be ensured whether the oxygen content in the powder recovery circulation system 100 exceeds a preset value and affects the chemical properties of the powder. The oxygen detection sensor 90 is disposed at the exhaust end of the separation tank 20 to eliminate interference from the powder.

[0055] In some embodiments, the powder recovery circulation system 100 further includes an inert gas replenishing device for replenishing inert gas into the powder recovery circulation system 100. When the oxygen detection sensor 90 detects that the oxygen content in the powder recovery circulation system 100 exceeds a preset value, the inert gas replenishing device can be used to replenish the inert gas. In addition, due to the positive pressure characteristics of the power device 10, when the exhaust valve is working, it can prevent external air from entering the powder recovery circulation system 100 to cause oxygen content fluctuations. Therefore, the powder recovery circulation system 100 only needs to maintain a small amount of inert gas replenishment to achieve any required oxygen content, which greatly saves inert gas consumption compared to the traditional negative pressure adsorption conveying system.

[0056] In some embodiments, the powder recovery and circulation system 100 further includes a vibrating screen 95, which is disposed between the separation tank 20 and the storage tank 30. The vibrating screen 95 is used to screen the powder discharged from the discharge end of the separation tank 20 and discharge it to the storage tank 30. At present, the materials that can be successfully processed by selective laser sintering include paraffin wax, polymer, metal, ceramic powder and their composite materials, especially metal materials. After each sintering, the remaining metal powder particle ash produces metal spheroidization products, splash oxidation products, and residues. At this time, the remaining powder after sintering must be cleared of large particle waste in the powder through the vibrating screen 95 so that the remaining powder can be recycled.

[0057] In the embodiment of the present invention, the selective laser sintering equipment includes multiple, the discharge end of the storage tank 30 of each selective laser sintering equipment is operably connected to the feed end of the conveying tank 40, the exhaust end of the conveying tank 40 is operably connected to the feed end of the separation tank 20, and the discharge end of the first recovery tank 50 is operably connected to the feed end of the separation tank 20. In this way, the powder recovery circulation system 100 can realize the recovery of powders in multiple selective laser sintering equipment, thereby improving the recovery efficiency.

[0058] Based on the same inventive concept, the present invention also provides a control method for a powder recovery circulation system 100 of a selective laser sintering device, comprising the steps of:

[0059] S110: Detecting the powder remaining amount in the conveying tank 40. When the powder remaining amount in the conveying tank 40 is lower than a first preset remaining amount, controlling the power device 10 to start, the discharge end of the storage tank 30 to open, and the exhaust end of the conveying tank 40 to open;

[0060] Among them, the powder recovery circulation system 100 of the selective laser sintering equipment may include a controller, and a low-level meter 65 electrically connected to the controller is arranged on the conveying tank 40. The setting value of the low-level meter 65 is a first preset surplus. A pulse stop valve is provided at the discharge end of the storage tank 30, and a stop valve is provided at the exhaust end of the conveying tank 40. In this way, when the low-level meter 65 detects that the powder surplus in the conveying tank 40 is lower than the first preset surplus, the controller receives this signal and controls the pulse stop valve at the discharge end of the storage tank 30 to open, and the stop valve at the exhaust end of the conveying tank 40 to open.

[0061] Furthermore, the pulse stop valve can be controlled by the controller to adjust the discharge volume and discharge speed of the discharge end of the storage tank 30 .

[0062] S120: Detect the powder residue in the storage tank 30. When the powder residue in the storage tank 30 is lower than a second preset residue, control the power device 10 to stop, close the discharge end of the storage tank 30, and close the exhaust end of the conveying tank 40.

[0063] Among them, a low-level meter 65 electrically connected to the controller is provided on the storage tank 30, and the setting value of the low-level meter 65 is a second preset surplus. In this way, when the low-level meter 65 detects that the powder surplus in the storage tank 30 is lower than the second preset surplus, the controller receives this signal and controls the pulse stop valve at the discharge end of the storage tank 30 to close, and the stop valve at the exhaust end of the conveying tank 40 to close.

[0064] S130: Detecting the powder residue in the first recovery tank 50. When the powder residue in the first recovery tank 50 is higher than the third preset residue, the power device 10 is controlled to start and the discharge end of the first recovery tank 50 is opened. When the powder residue in the first recovery tank 50 is lower than the fourth preset residue, the power device 10 is controlled to stop and the discharge end of the first recovery tank 50 is closed.

[0065] Among them, a high level meter 60 and a low level meter 65 electrically connected to the controller are provided on the first recovery tank 50, the setting value of the high level meter 60 is the third preset surplus, the setting value of the low level meter 65 is the fourth preset surplus, and a pulse stop valve electrically connected to the controller is provided at the discharge end of the first recovery tank 50. In this way, when the high level meter 60 detects that the powder surplus in the first recovery tank 50 is higher than the third preset surplus, the controller receives this signal and controls the pulse stop valve at the discharge end of the first recovery tank 50 to open, and when the low level meter 65 detects that the powder surplus in the first recovery tank 50 is lower than the fourth preset surplus, the controller receives this signal and controls the pulse stop valve at the discharge end of the first recovery tank 50 to close.

[0066] S140: Detect the powder residue in the separation tank 20. When the powder residue in the separation tank 20 is higher than the fifth preset residue, control the discharge end of the separation tank 20 to open and the feed end of the storage tank 30 to open. When the powder residue in the separation tank 20 is lower than the sixth preset residue or the powder residue in the storage tank 30 is higher than the seventh preset residue, control the discharge end of the separation tank 20 to close and the feed end of the storage tank 30 to close.

[0067] Among them, the separation tank 20 is provided with a high-level material level meter 60 and a low-level material level meter 65 electrically connected to the controller, the setting value of the high-level material level meter 60 is the fifth preset margin, and the setting value of the low-level material level meter 65 is the sixth preset margin. The storage tank 30 is also provided with a high-level material level meter 60 electrically connected to the controller, and the setting value of the high-level material level meter 60 is the seventh preset margin. A stop valve 70 electrically connected to the controller is provided at the discharge end of the separation tank 20 or the feed end of the storage tank 30. In this way, when the high-level level meter 60 of the separation tank 20 detects that the powder residue in the separation tank 20 is higher than the fifth preset residue, the controller receives this signal and controls the stop valve 70 at the discharge end of the separation tank 20 to open; when the low-level level meter 65 of the separation tank 20 detects that the powder residue in the separation tank 20 is lower than the sixth preset residue or when the high-level level meter 60 of the storage tank 30 detects that the powder residue in the storage tank 30 is higher than the seventh preset residue, the controller receives this signal and controls the stop valve 70 at the discharge end of the separation tank 20 or the feed end of the storage tank 30 to close.

[0068] It should be understood that the powder in the separation tank 20 can be discharged into the storage tank 30 under the action of gravity, so there is no need to use the positive pressure of the power device 10 to achieve transportation.

[0069] Further, when the powder residue in the separation tank 20 is higher than the fifth preset residue, the discharge end of the separation tank 20 is controlled to be opened and the feed end of the storage tank 30 is controlled to be opened, and the vibration screen 95 can also be controlled to start to sieve the powder. When the powder residue in the separation tank 20 is lower than the sixth preset residue or the powder residue in the storage tank 30 is higher than the seventh preset residue, the discharge end of the separation tank 20 is controlled to be closed and the feed end of the storage tank 30 is controlled to be closed, and the vibration screen 95 is also controlled to stop.

[0070] In some embodiments, the control method of the powder recovery circulation system 100 of the selective laser sintering equipment further includes the steps of:

[0071] S150: Detect the powder residue in the second recovery tank 80. When the powder residue in the second recovery tank 80 is higher than the eighth preset residue, control the power device 10 to start and open the discharge end of the second recovery tank 80. When the powder residue in the second recovery tank 80 is lower than the ninth preset residue, control the power device 10 to stop and close the discharge end of the second recovery tank 80.

[0072] Among them, a high level meter 60 and a low level meter 65 electrically connected to the controller are provided on the second recovery tank 80, the setting value of the high level meter 60 is the eighth preset surplus, the setting value of the low level meter 65 is the ninth preset surplus, and a pulse stop valve electrically connected to the controller is provided at the discharge end of the second recovery tank 80. In this way, when the high level meter 60 detects that the powder surplus in the second recovery tank 80 is higher than the eighth preset surplus, the controller receives this signal and controls the pulse stop valve at the discharge end of the second recovery tank 80 to open, and when the low level meter 65 detects that the powder surplus in the second recovery tank 80 is lower than the ninth preset surplus, the controller receives this signal and controls the pulse stop valve at the discharge end of the second recovery tank 80 to close.

[0073] In some embodiments, the control method of the powder recovery circulation system 100 of the selective laser sintering equipment further includes the steps of:

[0074] S160: Control the power device 10 to start, the air inlet 751 of the powder post-processing platform 75 to open, and the powder suction port 752 to open.

[0075] Among them, a stop valve 70 electrically connected to the controller can be set at the air inlet 751 and the powder suction port 752 of the powder post-processing platform 75. In this way, when the powder suction function is started, the stop valve 70 at the air inlet 751 and the powder suction port 752 of the powder post-processing platform 75 can be opened to complete the powder suction.

[0076] In some embodiments, the control method of the powder recovery circulation system 100 of the selective laser sintering equipment further includes the steps of:

[0077] S170: Control the aerobic detection sensor 90 to detect the oxygen content in the powder recovery circulation system 100. When the oxygen content detected by the aerobic detection sensor 90 is higher than the preset oxygen content value, adjust the inert gas content in the powder recovery circulation system 100 so that the oxygen content in the powder recovery circulation system 100 is lower than the preset oxygen content value.

[0078] Among them, the powder recovery circulation system 100 is also provided with an inert gas replenishing device and a stop valve 70 electrically connected to the controller and located at the exhaust port of the inert gas replenishing device. The aerobic detection sensor 90 is electrically connected to the controller. In this way, when the oxygen content detected by the aerobic detection sensor 90 is higher than the preset oxygen content value, the stop valve 70 of the inert gas replenishing device is controlled to open; when the oxygen content detected by the aerobic detection sensor 90 is lower than the preset oxygen content value, the stop valve 70 of the inert gas replenishing device is controlled to close.

[0079] It should be understood that when the powder recovery circulation system 100 of the selective laser sintering equipment is on standby, all the stop valves 70 are in a closed state, the power device 10 is stopped, and the level meters on each tank body monitor the powder state to determine whether to start the conveying or recovery function.

[0080] It should also be understood that the present invention is not limited to being performed in the order of the above steps.

[0081] The powder recovery circulation system 100 of the selective laser sintering equipment and the control method thereof provided by the embodiment of the present invention have the following beneficial effects:

[0082] Under the action of the power device 10, the powder circulates between the storage tank 30, the conveying tank 40 and the separation tank 20 and circulates between the first recovery tank 50 and the separation tank 20, so that the powder can be recovered. Therefore, the powder recovery circulation system 100 is simple to operate, has low labor intensity and good safety.

[0083] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0084] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A powder recovery circulation system for a selective laser sintering device, characterized in that: It includes a power device, a separation tank, a storage tank, a conveying tank of the selective laser sintering device, and a first recovery tank connected to the working chamber of the selective laser sintering device; The discharge end of the separation tank is operably connected to the feed end of the storage tank; The discharge end of the storage tank is operably connected to the feed end of the conveying tank, and the exhaust end of the conveying tank is operably connected to the feed end of the separation tank; The discharge end of the first recovery tank is operably connected to the feed end of the separation tank; The power device comprises an air suction port and an exhaust port, wherein the exhaust port is operably connected to the discharge end of the storage tank and the discharge end of the first recovery tank, and the air suction port is connected to the exhaust end of the separation tank.

2. The powder recovery circulation system of the selective laser sintering equipment according to claim 1, characterized in that: The powder recovery circulation system also includes a powder post-processing platform and a second recovery tank; The powder post-processing platform also has a discharge port, which is connected to the feed end of the second recovery tank. The discharge end of the second recovery tank is operably connected to the feed end of the separation tank. The exhaust port of the power device is operably connected to the discharge end of the second recovery tank.

3. The powder recovery circulation system of the selective laser sintering equipment according to claim 2, characterized in that: The powder post-processing platform has an air inlet and a powder suction port separated from the discharge port, the powder suction port is operably connected to the feed end of the separation tank, and the exhaust port of the power device is operably connected to the air inlet.

4. The powder recovery circulation system of the selective laser sintering equipment according to claim 1, characterized in that: The powder recovery circulation system is a closed powder recovery circulation system, and the powder recovery circulation system is filled with inert gas.

5. The powder recovery circulation system of the selective laser sintering equipment according to claim 4, further comprising an oxygen detection sensor, wherein the oxygen detection sensor is used to detect the oxygen content in the powder recovery circulation system.

6. The powder recovery circulation system of the selective laser sintering equipment according to claim 1, characterized in that: The discharge end of the storage tank and the discharge end of the first recovery tank are both provided with a pulse stop valve, and the pulse stop valve is used to adjust the discharge amount and discharge speed of the discharge end of the storage tank and the discharge end of the first recovery tank.

7. The powder recovery circulation system of the selective laser sintering equipment according to claim 1, characterized in that: The powder recovery circulation system further includes a vibrating screen, which is disposed between the separation tank and the storage tank, and is used to screen the powder discharged from the discharge end of the separation tank and discharge it into the storage tank.

8. The powder recovery circulation system of the selective laser sintering equipment according to claim 1, characterized in that: The selective laser sintering equipment includes multiple devices, and the feed end of the conveying tank of each selective laser sintering device is operably connected to the discharge end of the storage tank, the exhaust end of the conveying tank is operably connected to the feed end of the separation tank, and the discharge end of the first recovery tank is operably connected to the feed end of the separation tank.

9. A method for controlling a powder recovery circulation system of a selective laser sintering device according to any one of claims 1 to 8, characterized in that: Includes steps: Detecting the powder remaining amount in the conveying tank, and when the powder remaining amount in the conveying tank is lower than a first preset remaining amount, controlling the power device to start, the discharge end of the storage tank to open, and the exhaust end of the conveying tank to open; Detecting the powder remaining amount in the storage tank, and when the powder remaining amount in the storage tank is lower than a second preset remaining amount, controlling the power device to stop, the discharge end of the storage tank to close, and the exhaust end of the conveying tank to close; Detecting the powder remaining amount in the first recovery tank, and when the powder remaining amount in the first recovery tank is higher than a third preset remaining amount, controlling the power device to start and the discharge end of the first recovery tank to open; and when the powder remaining amount in the first recovery tank is lower than a fourth preset remaining amount, controlling the power device to stop and the discharge end of the first recovery tank to close; Detect the powder residue in the separation tank. When the powder residue in the separation tank is higher than the fifth preset residue, control the discharge end of the separation tank to open and the feed end of the storage tank to open. When the powder residue in the separation tank is lower than the sixth preset residue or the powder residue in the storage tank is higher than the seventh preset residue, control the discharge end of the separation tank to close and the feed end of the storage tank to close.

10. The control method of the powder recovery circulation system of the selective laser sintering equipment according to claim 9, characterized in that: The powder recovery circulation system is a closed powder recovery circulation system, inert gas is filled in the powder recovery circulation system, and the powder recovery circulation system also includes an oxygen detection sensor, which is used to detect the oxygen content in the powder recovery circulation system; The control method of the powder recovery circulation system further comprises the steps of: Controlling the oxygen detection sensor to detect the oxygen content in the powder recovery circulation system; When the oxygen content detected by the oxygen detection sensor is higher than a preset oxygen content value, the inert gas content in the powder recovery circulation system is adjusted to make the oxygen content in the powder recovery circulation system lower than the preset oxygen content value.

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