A Closed-Loop Management Device and Method for Sieving, Recycling and Powder Feeding in Powder Bed Additive Manufacturing

Abstract

The present invention discloses a closed-loop management device and method for screening, recycling and powder feeding in powder bed additive manufacturing; it includes a powder screening bin, a powder recycling bin, a two-position three-way solenoid valve, a two-position two-way solenoid valve, a powder inlet of the powder screening bin, which is connected to the outer area of the forming cylinder through a powder feeding pipe; a powder outlet of the powder screening bin, which is connected to the outer area of the powder cylinder through a powder conveying pipe; the first outlet of the two-position three-way solenoid valve is connected to the powder screening bin through a pipe; the second outlet of the two-position three-way solenoid valve is connected to the connection between the powder outlet of the powder screening bin and the powder conveying pipe through a pipe. During the additive manufacturing process, the present invention implements closed-loop management for powder screening, recycling, powder feeding, etc., overcoming the problems in the traditional process that during the printing process, due to the large size of the printed part or insufficient powder material, etc., external powder screening is required and then the equipment needs to be opened to add powder, resulting in printing interruption and thus affecting the performance of the sample part.

Description

Technical Field

[0001] The present invention relates to the field of metal additive manufacturing, and particularly to a closed-loop management device and method for screening, recycling, and powder feeding in powder bed additive manufacturing. Background Art

[0002] Compared with traditional manufacturing, additive manufacturing has the advantages of not requiring tools and molds, short development cycles, and the ability to form complex parts. Especially for powder bed additive manufacturing technology, the manufactured parts have high dimensional accuracy and excellent mechanical properties, and have developed rapidly in recent years. Currently, the powders mainly studied and used are those made of iron-based alloys, titanium alloys, aluminum alloys, nickel-based alloys, cobalt-based alloys, etc.

[0003] Powder bed additive manufacturing technology usually prepares the powder before printing, and ensures that the powder quality meets the requirements through multiple operations such as sieving and drying. Selective laser melting is a representative technology of powder bed additive manufacturing. The powder is added to the dosing cylinder, and the powder is sent to the forming cylinder by a powder spreading vehicle, and the excess powder and splashed residues are pushed into the recycling bin for further processing.

[0004] During the printing process, if printing large-sized parts or when the powder material is insufficient, it is often necessary to take out the powder for sieving to remove impurities and residues, and then add it to the machine again. Some powders also need to be dried, which affects the printing efficiency, and even more, the performance of the parts is affected due to the interruption in the middle. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above-mentioned disadvantages and deficiencies of the prior art, and provide a closed-loop management device and method for screening, recycling, and powder feeding in powder bed additive manufacturing. It overcomes the problems of printing interruption and printing performance in the traditional process when printing large-sized parts or when the powder material is insufficient.

[0006] The present invention is achieved by the following technical solutions:

[0007] A closed-loop management device for screening, recycling, and powder feeding in powder bed additive manufacturing includes:

[0008] A forming cavity 100;

[0009] A powder cylinder 130;

[0010] A forming cylinder 160;

[0011] A powder screening bin 210;

[0012] A powder recycling bin 240;

[0013] A two-position three-way solenoid valve 260;

[0014] Two-position two-way solenoid valve 230;

[0015] The powder inlet of the powder screening bin 210 is connected to the outer area of the forming cylinder 160 through the powder inlet pipe 200;

[0016] The powder outlet of the powder screening bin 210 is connected to the outer area of the powder cylinder 130 through the powder conveying pipe 220;

[0017] The first outlet of the two-position three-way solenoid valve 260 is connected to the powder screening bin 210 through a pipeline;

[0018] The second outlet of the two-position three-way solenoid valve 260 is connected to the powder outlet of the powder screening bin 210 and the connection point of the powder conveying pipe 220 through a pipeline;

[0019] The powder recovery bin 240 is connected to the junction between the powder outlet of the powder screening bin 210 and the powder conveying pipe 220 through a two-position two-way solenoid valve 230 .

[0020] The air inlet of the two-position three-way solenoid valve 260 is connected to the air inlet pipe 270;

[0021] When the two-position three-way solenoid valve 260 is in a closed state, the gas coming from the air inlet pipe 270 is connected to the powder conveying pipe 220;

[0022] When the two-position three-way solenoid valve 260 is in an open state, the gas coming in from the air inlet pipe 270 is connected to the powder screening bin 210 .

[0023] A position sensor 250 is installed on one side of the powder screening bin 210 .

[0024] A vibrator 214 is disposed on the side wall of the powder screening bin 210 .

[0025] The powder screening bin 210 has a screen 211 built therein; a bin door switch 212 is provided on the side wall of the powder screening bin 210 at the outer edge of the screen 211 ; the bin door switch 212 is connected to the residue collection bin 213 .

[0026] The powder screening bin 210 is in a V-shaped funnel shape.

[0027] A closed-loop management method for screening, recycling and powder feeding in powder bed additive manufacturing, including a circulation mode and a non-circulation mode;

[0028] Loop Mode:

[0029] Step S11: During operation, the powder cylinder 130 rises, and the powder spreading vehicle 120 pushes the powder in the powder cylinder 130 to the forming cylinder 160. During the spreading process, the excess powder and the splashing powder are sent to the powder inlet pipe 200;

[0030] Step S12: The powder and spatter fall into the powder screening bin 210 through the powder inlet pipe 200; as the powder in the powder screening bin 210 gradually increases, the powder screening bin 210 gradually moves downward and touches the position sensor 250; the powder screening operation starts;

[0031] Step S13: The vibrator 214 is turned on, the two-way three-way solenoid valve 260 is closed, the two-way two-way solenoid valve 230 is closed, the bin door switch 212 is closed, and the air inlet pipe 270 starts to admit air, and the air flows into the powder delivery pipe 220;

[0032] The powder at the powder outlet of the powder screening bin 210 is sent by the gas through the powder delivery pipe 220 to the powder dropping trough 110 above the powder cylinder 130, and then evenly falls into the powder cylinder from the powder dropping trough 110; the powder screening bin 210 slowly rises;

[0033] Step S14: The powder screening bin 210 returns to its original position, touches the position sensor 250, and the vibrator 214 stops working; the two-way three-way solenoid valve 260 is opened, the bin door switch 212 is opened, the air inlet pipe 270 admits air, and through the first outlet of the two-way three-way solenoid valve 260, the spatter residue is blown into the residue collection bin 213;

[0034] Step S15: After the spatter residue on the sieve mesh 211 is cleaned up, the bin door switch 212 is closed, the air inlet pipe 270 stops admitting air, and the two-way three-way solenoid valve 260 is closed;

[0035] Step S16: Repeat steps S11 to S15 to complete the printing work;

[0036] Non-cyclic mode:

[0037] Step S21: During operation, the powder cylinder 130 rises, and the powder spreading vehicle 120 evenly pushes the powder in the powder cylinder 130 to the forming cylinder 160. During the spreading process, the excess powder and spatter are sent to the powder inlet pipe 200;

[0038] Step S22: The powder and spatter fall into the powder screening bin 210 through the powder inlet pipe 200; as the powder in the powder screening bin 210 gradually increases, the powder screening bin 210 gradually moves downward and touches the position sensor 250; the powder screening operation starts;

[0039] Step S23: The vibrator 214 is turned on, the two-way two-way solenoid valve 230 is opened, the bin door switch 212 is closed, the air inlet pipe 270 does not admit air, and the powder at the powder outlet of the powder screening bin 210 directly falls to the powder recovery bin 240 by gravity;

[0040] Step S24: The powder screening bin 210 returns to its original position, touches the position sensor 250, and the vibrator 214 stops working; the two-position three-way solenoid valve 260 opens, the bin door switch 212 opens, the intake pipe 270 intakes air, and through the first outlet of the two-position three-way solenoid valve 260, the splashed residues are blown into the residue collection bin 213;

[0041] Step S25: After the residues on the screen 211 are cleaned up, the bin door switch 212 closes, the intake pipe 270 stops intaking air, and the two-position three-way solenoid valve 260 closes;

[0042] Step S26: Repeat steps S21 to S25 to complete the printing work.

[0043] The present invention has the following advantages and effects compared with the prior art:

[0044] During the additive manufacturing operation of the present invention, through the organic combination of the externally provided powder screening bin 210, powder recovery bin 240,

[0045] two-position three-way solenoid valve 260, two-position two-way solenoid valve 230 and pipeline components, a closed-loop management system for powder screening, recovery, powder feeding, etc. is formed with the forming cavity. It overcomes the problems in the traditional process that during the printing process, due to the large size of the printed part or insufficient powder material, etc., external powder screening is required and then the equipment needs to be opened to add powder, resulting in printing interruption and affecting the performance of the sample parts.

[0046] Adopt the closed-loop management device for screening, recovery, powder feeding, etc. of the present invention; when the current layer of printing is completed and powder spreading is carried out, the excess powder and splashed residues are sent to the powder screening bin through the pipeline. When the powder screening bin reaches a certain weight, it will trigger the position sensor switch downward and start the powder screening operation. If during the printing process, the switch of the powder recovery bin is in the closed state, the lower pipeline of the intake pipe sends air to send the powder back to the powder cylinder; if the printing is over, the powder recovery bin is in the open state, and the powder smoothly falls into the powder recovery bin. After the powder screening is completed, the powder screening bin returns to its initial position. Gas is introduced to blow the residues into the residue collection bin. Through the present invention, the powder can be processed in place, there is no need to open the bin door to add powder when the powder is insufficient, avoiding adverse factors such as powder oxidation and moisture absorption, ensuring the consistency of the forming efficiency and performance of the parts, and reducing the danger of metal powder. Brief Description of the Drawings

[0047] Figure 1 It is a schematic structural diagram of the closed-loop management device for screening, recovery and powder feeding in powder bed additive manufacturing of the present invention;

[0048] Figure 2 It is a partially enlarged connection schematic diagram of the powder screening bin, two-position three-way solenoid valve and two-position two-way solenoid valve of the present invention;

[0049] In the figure: forming cavity 100; powder dropping trough 110; powder spreading vehicle 120; powder cylinder 130; laser beam 140; workpiece 150; forming cylinder 160; powder inlet pipe 200; powder screening bin 210; screening mesh 211; bin door switch 212; residue collection bin 213; vibrator 214; powder conveying pipe 220; two-position two-way solenoid valve 230; powder recycling bin 240; position sensor 250; two-position three-way solenoid valve 260; air inlet pipe 270. Detailed implementation mode

[0050] The present invention will be further described in detail below in conjunction with specific embodiments.

[0051] The present invention discloses a closed-loop management device for screening, recycling and powder feeding in powder bed additive manufacturing, including: forming cavity 100, powder cylinder 130, forming cylinder 160, powder screening bin 210, powder recycling bin 240, two-position three-way solenoid valve 260, two-position two-way solenoid valve 230;

[0052] The inside of the forming cavity 100 is in a closed state and is filled with inert gas for protection.

[0053] The powder screening bin 210 is in a sealed state with the outside.

[0054] The powder inlet of the powder screening bin 210 is connected to the outer area of the forming cylinder 160 through the powder inlet pipe 200;

[0055] The powder outlet of the powder screening bin 210 is connected to the outer area of the powder cylinder 130 through the powder conveying pipe 220;

[0056] The first outlet of the two-position three-way solenoid valve 260 is connected to the powder screening bin 210 through a pipeline;

[0057] The second outlet of the two-position three-way solenoid valve 260 is connected to the connection point between the powder outlet of the powder screening bin 210 and the powder conveying pipe 220 through a pipeline;

[0058] The powder recycling bin 240 is connected to the connection point between the powder outlet of the powder screening bin 210 and the powder conveying pipe 220 through the two-position two-way solenoid valve 230.

[0059] The air inlet of the two-position three-way solenoid valve 260 is connected to the air inlet pipe 270;

[0060] When the two-position three-way solenoid valve 260 is in the closed state, the gas coming in from the air inlet pipe 270 is connected to the powder conveying pipe 220;

[0061] When the two-position three-way solenoid valve 260 is in the open state, the gas coming in from the air inlet pipe 270 is connected to the powder screening bin 210.

[0062] The intake pipe 270 is used to enhance the pressure, smoothly transport the powder, and blow the residue into the residue collection bin 213. After the gas comes out of the two-position three-way solenoid valve 260, it is connected to the powder screening bin 210 through a pipeline. The diameter of this pipeline first changes from a large diameter to a small diameter and then connects to the powder screening bin 210.

[0063] The gas introduced by the intake pipe 270 is the same as the protective gas in the molding cavity 100, which can prevent the powder from oxidation or mixing with other impurities.

[0064] On one side of the powder screening bin 210, a position sensor 250 is installed. In the initial state, it is above the position sensor 250. As the powder inside the powder screening bin 210 increases, when the powder screening bin 210 moves downward and touches the lower position sensor, the powder screening operation is carried out; when the powder gradually decreases and touches the upper position sensor again, the powder screening ends.

[0065] An oscillator 214 is provided on the side wall of the powder screening bin 210.

[0066] A sieve mesh 211 is installed inside the powder screening bin 210; on the side wall of the powder screening bin 210 at the outer edge of the sieve mesh 211, a bin door switch 212 is provided; the bin door switch 212 is connected to the residue collection bin 213. The bin door switch 212 can control the opening and closing of the bin door through a servo motor or a motor.

[0067] The sieve mesh 211 is connected to the powder screening bin 210 through a buckle, which is convenient for replacing sieve meshes with different mesh numbers for different powders.

[0068] The powder screening bin 210 is in a V-shaped funnel shape.

[0069] The powder bed additive manufacturing screening, recycling, and powder feeding closed-loop management method of the present invention includes a circulation mode and a non-circulation mode, which are specifically as follows:

[0070] Circulation mode:

[0071] Step S11: During operation, the powder cylinder 130 rises, and the powder spreading vehicle 120 pushes the powder in the powder cylinder 130 flat to the molding cylinder 160. During the spreading process, the excess powder and splashes are sent to the powder inlet pipe 200;

[0072] Step S12: The powder and splashes fall into the powder screening bin 210 through the powder inlet pipe 200; as the powder in the powder screening bin 210 gradually increases, the powder screening bin 210 gradually moves downward and touches the position sensor 250; the powder screening operation starts;

[0073] Step S13: The oscillator 214 is turned on, the two-position three-way solenoid valve 260 is closed, the two-position two-way solenoid valve 230 is closed, the bin door switch 212 is closed, and the intake pipe 270 starts to intake air, and the gas flows into the powder conveying pipe 220;

[0074] The powder at the powder outlet of the powder screening bin 210 is sent into the powder dropping trough 110 above the powder cylinder 130 by gas through the powder conveying pipe 220, and then evenly falls into the powder cylinder from the powder dropping trough 110; the powder screening bin 210 slowly rises;

[0075] Step S14: The powder screening bin 210 returns to its original position, touches the position sensor 250, and the vibrator 214 stops working; the two-position three-way solenoid valve 260 opens, the bin door switch 212 opens, the air inlet pipe 270 intakes air, and through the first outlet of the two-position three-way solenoid valve 260, the splashed residues are blown into the residue collection bin 213;

[0076] Step S15: After the splashed residues on the sieve mesh 211 are cleaned up, the bin door switch 212 closes, the air inlet pipe 270 stops intaking air, and the two-position three-way solenoid valve 260 closes;

[0077] Step S16: Repeat steps S11 to S15 to complete the printing work;

[0078] Non-cyclic mode:

[0079] Step S21: During operation, the powder cylinder 130 rises, and the powder spreading vehicle 120 pushes the powder in the powder cylinder 130 flat to the molding cylinder 160. During the spreading process, the excess powder and splashes are sent to the powder inlet pipe 200;

[0080] Step S22: The powder and splashes fall into the powder screening bin 210 through the powder inlet pipe 200; as the powder in the powder screening bin 210 gradually increases, the powder screening bin 210 gradually moves down and touches the position sensor 250; the powder screening operation starts;

[0081] Step S23: The vibrator 214 is turned on, the two-position two-way solenoid valve 230 is turned on, the bin door switch 212 is closed, the air inlet pipe 270 does not intake air, and the powder at the powder outlet of the powder screening bin 210 directly falls to the powder recovery bin 240 by gravity;

[0082] Step S24: The powder screening bin 210 returns to its original position, touches the position sensor 250, and the vibrator 214 stops working; the two-position three-way solenoid valve 260 opens, the bin door switch 212 opens, the air inlet pipe 270 intakes air, and through the first outlet of the two-position three-way solenoid valve 260, the splashed residues are blown into the residue collection bin 213;

[0083] Step S25: After the residues on the sieve mesh 211 are cleaned up, the bin door switch 212 closes, the air inlet pipe 270 stops intaking air, and the two-position three-way solenoid valve 260 closes;

[0084] Step S26: Repeat steps S21 to S25 to complete the printing work.

[0085] The mentioned powder dropping tank 110 has a height slightly higher than that of the powder spreading vehicle 120, so that there is no interference between them; inside the powder dropping tank 110, the uniformity of powder dropping is ensured by means of shunting.

[0086] The present invention adopts a closed-loop management system for the powder, which greatly saves the time of manual powder screening, improves the efficiency, and avoids the influence of external powder screening on the performance of parts.

[0087] The implementation mode of the present invention is not limited by the above-mentioned embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A closed-loop management method for screening, recycling and powder feeding in powder bed additive manufacturing, characterized in that Based on Realize the closed-loop management device for screening, recycling and powder feeding in powder bed additive manufacturing; The closed-loop management device for screening, recycling and powder feeding in powder bed additive manufacturing includes a forming cavity (100), a powder cylinder (130), a forming cylinder (160), a powder screening bin (210), a powder recycling bin (240), a two-position three-way solenoid valve (260) and a two-position two-way solenoid valve (230); The powder inlet of the powder screening bin (210) is connected to the outer area of the forming cylinder (160) through a powder inlet pipe (200); The powder outlet of the powder screening bin (210) is connected to the outer area of the powder cylinder (130) through a powder delivery pipe (220); The first outlet of the two-position three-way solenoid valve (260) is connected to the powder screening bin (210) through a pipeline; The second outlet of the two-position three-way solenoid valve (260) is connected to the connection point of the powder outlet of the powder screening bin (210) and the powder delivery pipe (220) through a pipeline; The powder recycling bin (240) is connected to the connection point of the powder outlet of the powder screening bin (210) and the powder delivery pipe (220) through a two-position two-way solenoid valve (230); The air inlet of the two-position three-way solenoid valve (260) is connected to an air inlet pipe (270); When the two-position three-way solenoid valve (260) is in the closed state, the gas coming in from the air inlet pipe (270) is connected to the powder delivery pipe (220); When the two-position three-way solenoid valve (260) is in the open state, the gas coming in from the air inlet pipe (270) is connected to the powder screening bin (210); A position sensor (250) is installed on one side of the powder screening bin (210); An oscillator (214) is arranged on the side wall of the powder screening bin (210); The closed-loop management method for screening, recycling and powder feeding in powder bed additive manufacturing includes a circulating mode and a non-circulating mode; Circulating mode: Step S11: During operation, the powder cylinder (130) rises, and the powder spreading vehicle (120) evenly pushes the powder in the powder cylinder (130) to the forming cylinder (160). During the spreading process, the excess powder and splashes are sent to the powder inlet pipe (200); Step S12: The powder and splashes fall into the powder screening bin (210) through the powder inlet pipe (200); As the powder in the powder screening bin (210) gradually increases, the powder screening bin (210) gradually moves down to touch the position sensor (250); The powder screening operation starts; Step S13: The oscillator (214) is turned on, the two-position three-way solenoid valve (260) is closed, the two-position two-way solenoid valve (230) is closed, the bin door switch (212) is closed, and the air inlet pipe (270) starts to admit air, and the gas flows into the powder delivery pipe (220); The powder at the powder outlet of the powder screening bin (210) is sent by the gas through the powder delivery pipe (220) to the powder dropping groove (110) above the powder cylinder (130), and then evenly falls into the powder cylinder from the powder dropping groove (110); The powder screening bin (210) slowly rises; Step S14: The powder screening bin (210) returns to its original position, touches the position sensor (250), and the vibrator (214) stops working; the two-position three-way solenoid valve (260) opens, the bin door switch (212) opens, the air inlet pipe (270) intakes air, and through the first outlet of the two-position three-way solenoid valve (260), the splashing residues are blown into the residue collection bin (213). Step S15: After the splashing residues on the screen (211) are cleaned up, the bin door switch (212) closes, the air inlet pipe (270) stops intaking air, and the two-position three-way solenoid valve (260) closes. Step S16: Repeat steps S11 to S15 to complete the printing work. Non-cyclic mode: Step S21: During operation, the powder cylinder (130) rises, and the powder spreading vehicle (120) horizontally pushes the powder in the powder cylinder (130) to the forming cylinder (160). During the spreading process, the excess powder and splashes are sent to the powder inlet pipe (200). Step S22: The powder and splashes fall into the powder screening bin (210) through the powder inlet pipe (200); as the powder in the powder screening bin (210) gradually increases, the powder screening bin (210) gradually moves down and touches the position sensor (250); the powder screening operation starts. Step S23: The vibrator (214) is turned on, the two-position two-way solenoid valve (230) is turned on, the bin door switch (212) closes, the air inlet pipe (270) does not intake air, and the powder at the powder outlet of the powder screening bin (210) directly falls into the powder recovery bin (240) by gravity. Step S24: The powder screening bin (210) returns to its original position, touches the position sensor (250), and the vibrator (214) stops working; the two-position three-way solenoid valve (260) opens, the bin door switch (212) opens, the air inlet pipe (270) intakes air, and through the first outlet of the two-position three-way solenoid valve (260), the splashing residues are blown into the residue collection bin (213). Step S25: After the residues on the screen (211) are cleaned up, the bin door switch (212) closes, the air inlet pipe (270) stops intaking air, and the two-position three-way solenoid valve (260) closes. Step S26: Repeat steps S21 to S25 to complete the printing work.

2. The powder bed additive manufacturing screening, recycling, powder feeding closed-loop management method according to claim 1, wherein: The powder screening bin (210) is internally provided with a screen (211); a bin door switch (212) is provided on the side wall of the powder screening bin (210) at the outer edge of the screen (211); the bin door switch (212) is connected to the residue collection bin (213).

3. The powder bed additive manufacturing screening, recycling, powder feeding closed-loop management method according to claim 1, characterized in that: The powder screening bin (210) is in a V-shaped funnel shape.

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