Binder spraying additive manufacturing device based on selective powder laying mode

Abstract

The invention discloses a binder spraying additive manufacturing device based on a selective powder laying mode. Belongs to the technical field of additive manufacturing. The device comprises a shell, a binder spraying device, a powder laying device, a lifting platform and other equipment. Wherein the binder spraying device comprises a plurality of binder storage bins, binder nozzles and near infrared lamps, and the binder nozzles and the near infrared lamps correspond to the binder storage bins; the powder spreading device comprises a feeding port, a powder spreading roller arranged below the feeding port, scrapers arranged on the two sides of the powder spreading roller, a powder suction device and a powder discharging device, wherein the powder suction device and the powder discharging device are arranged in the powder spreading roller. According to the binder spraying additive manufacturing equipment capable of selectively laying powder, two different powder materials can be accurately laid in the same flat layer, the two or more powder materials are bonded together, and the binder spraying additive manufacturing equipment is remarkably helpful to the machinery industry and the material industry.

Description

Technical Field

[0001] The invention belongs to the technical field of additive manufacturing and relates to a binder jet additive manufacturing device based on a selective powder spreading mode. Background Art

[0002] At present, binder jetting additive manufacturing is an additive manufacturing technology that uses binders and powdered materials to manufacture three-dimensional objects. The advantages of this technology include the ability to manufacture large-scale objects, compatibility with a variety of materials, high material utilization, high molding efficiency, and suitability for rapid prototyping, production of complex parts, and product customization. It is especially used for metal printing, which is not affected by laser absorption and warping when the material melts. However, its disadvantage is that most of the existing binder jetting additive manufacturing can only print a single layer of one material, resulting in the inability to complete the production of some printed parts that require spatial heterogeneous material distribution. Summary of the invention

[0003] In view of the above problems, the purpose of the present invention is to propose a binder jetting additive manufacturing device based on a selective powder spreading mode, aiming to solve the problem that the current binder jetting additive manufacturing cannot print parts made of spatially heterogeneous materials.

[0004] The technical solution of the present invention is: a binder jetting additive manufacturing device based on a selective powder spreading mode according to the present invention comprises a housing, and a powder inlet is arranged above the housing;

[0005] An adhesive spraying device is arranged inside the shell, and the adhesive spraying device includes a plurality of adhesive storage bins, each of which is connected to a conduit at its lower end, and an adhesive nozzle is arranged at its lower end.

[0006] Furthermore, the adhesive spraying device is fixed and moved by four guide rails connected to the inner wall of the shell;

[0007] The two rails on the upper end are dust-free belt electric slides that control the movement of the injection device;

[0008] The two guide rails on both sides are ball bearing guide rails.

[0009] Furthermore, there are three rows of adhesive nozzles, and a small heating coil is arranged above each adhesive nozzle.

[0010] Furthermore, a plurality of near-infrared lamps are arranged behind the adhesive nozzle, and the near-infrared lamps are composed of two rows of near-infrared lamp beads.

[0011] Furthermore, the powder inlet includes a powder feeding funnel a and a powder feeding funnel b.

[0012] The upper opening of the powder feeding funnel a is square, and shrinks downward from large to small to form a square shape;

[0013] The powder feeding funnel b has the same shape as the powder feeding funnel a.

[0014] Furthermore, a powder spreading box is arranged inside the shell and below the powder feeding hopper a and the powder feeding hopper b, and two fixed and movable guide rails are arranged below the powder spreading box, and the guide rails are dust-free belt electric slides.

[0015] Furthermore, the powder spreading box includes a powder spreading device a and a powder spreading device b, two feed ports corresponding to the powder feeding funnel a and the powder feeding funnel b are provided on the upper part of the powder spreading device a and the powder spreading device b, and a discharge port is provided at the end opposite to the feed port;

[0016] A powder spreading roller is arranged near the two discharge ports, scrapers are arranged on both sides of the powder spreading roller, and a powder suction device and a powder discharging device are symmetrically arranged on the upper and lower parts of the powder spreading roller.

[0017] Furthermore, the surface of the powder spreading roller is covered with holes;

[0018] Wherein, the diameter of the hole is less than 1 μm.

[0019] Furthermore, a nozzle is arranged on the lower surface of the powder dispensing device, and the diameter of the nozzle is the same as the diameter of the hole opened on the surface of the powder spreading roller;

[0020] The valves of the powder spreading roller and the nozzle of the powder dispensing device are connected to the monitoring system via wireless.

[0021] Furthermore, a printing platform is arranged at the center position at the lower part of the shell. The printing platform consists of a freely liftable lifting platform. The lifting platform is driven up and down by a screw rod, and four guide rods are arranged around it to ensure the stable lifting of the platform.

[0022] The beneficial effects of the present invention are as follows: the selective powder-laying binder jetting additive manufacturing equipment of the present invention can accurately lay two different powder materials in the same flat layer, and bond two or more powder materials together, which is of significant help to the machinery industry and the materials industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0024] Figure 2 yes Figure 1 Half section view of the main view;

[0025] Figure 3 yes Figure 1 Half section view of the left side;

[0026] Figure 4 It is a schematic diagram of the internal structure of the powder spreading device in the present invention;

[0027] Figure 5 It is a schematic diagram of the structure inside the binder injection device of the present invention;

[0028] Figure 6 It is a schematic diagram of the dust-free belt electric slide in the present invention;

[0029] Figure 7 It is a schematic diagram of powder feeding during the operation of the present invention;

[0030] Figure 8 It is a schematic diagram of powder spreading during the operation of the present invention;

[0031] Fig. 9 is a schematic diagram of binder injection during operation of the present invention;

[0032] In the figure: 1. shell, 2. powder inlet, 3. binder injection device, 4. powder spreading box, 5. lifting platform, 6. powder feeding funnel a, 7. powder feeding funnel b, 8. powder spreading device a, 9. powder spreading device b, 10. feeding port, 11. scraper, 12. powder suction device, 13. powder spreading roller, 14. powder unloading device, 15. binder storage bin, 16. binder nozzle, 17. near infrared lamp. DETAILED DESCRIPTION

[0033] The specific technical scheme of the present invention is further described in detail below with reference to specific examples.

[0034] like Figure 1-6 As shown, a binder jetting additive manufacturing device based on a selective powder spreading mode according to the present invention mainly comprises a housing 1, a powder inlet 2 is arranged above the housing 1 (top right side), and powder enters the device from the powder inlet 2 through a feeding device (not shown), and the powder inlet 2 comprises a powder feeding funnel a 6 and a powder feeding funnel b 7;

[0035] The adhesive spraying device 3 includes a plurality of adhesive storage bins 15, an adhesive nozzle 16 corresponding to each adhesive storage bin 15, and a near infrared lamp 17 disposed behind the adhesive nozzle 16;

[0036] Corresponding powder spreading boxes 4 are arranged below the powder feeding funnel a 6 and the powder feeding funnel b 7. The powder spreading box 4 is divided into a powder spreading device a 8 and a powder spreading device b 9. A feed port 10 is opened at the top of the powder spreading device a 8 and the powder spreading device b 9, and a discharge port is opened at the end opposite to the feed port 10. A powder spreading roller 13 is arranged below the discharge port 10, and scrapers 11 are arranged on both sides of the powder spreading roller 13. A powder suction device 12 and a powder discharging device 14 are arranged inside the powder spreading roller 13.

[0037] The upper opening of the powder feeding funnel a 6 is square, shrinking downward from large to small to form a square.

[0038] The powder feeding funnel b7 and the powder feeding funnel a6 have the same shape.

[0039] The width of the binder spraying device 3 is smaller than the distance between the powder spreading box 4 and the housing 1, so that the powder spreading box 4 can move freely;

[0040] A plurality of adhesive storage bins 15 are arranged above the adhesive spraying device 3 . The adhesive storage bins 15 are placed in parallel above the adhesive spraying device 3 , and a conduit is connected to the bottom of each adhesive storage bin 15 .

[0041] The adhesive storage bin 15 is connected to an adhesive nozzle 16 by a conduit below. The conduit is connected to the adhesive nozzle 16. The adhesive nozzle 16 has three rows. A small heating coil is arranged above each adhesive nozzle 16 to spray the adhesive.

[0042] A near infrared lamp 17 is arranged behind the adhesive nozzle 16. The near infrared lamp 17 is composed of two rows of near infrared lamp beads and is used to quickly solidify the adhesive sprayed part.

[0043] The binder injection device 3 (middle position) is fixed by four guide rails and can move stably forward and backward. The height of the guide rails is higher than the height of the powder box 4. The two upper ones are dust-free belt electric slides to control the movement of the injection device 3. Its closed design effectively isolates the entry of dust and ensures the stable operation of the machine; the two sides are ball bearing slides to ensure stable operation.

[0044] The powder spreading box 4 is arranged below the powder feeding funnel b 7 and the powder feeding funnel a 6, connected by two guide rails, and fixed and moved by the two guide rails, and can stably move left and right;

[0045] The guide rail is a dust-free belt electric slide.

[0046] The powder spreading box 4 is located below the powder feeding funnel, and the height of the powder spreading box 4 is lower than the height of the guide rail for fixing the binder spraying device 3;

[0047] The upper part of the powder spreading box 4 is provided with two feeding ports 10 corresponding to the powder feeding funnel b 7 and the powder feeding funnel a 6. The feeding ports 10 are designed to be wide at the top and narrow at the bottom, so that the powder can be fed into the corresponding feeding ports 10 accurately.

[0048] A powder spreading roller 13 is placed at the discharge port below the feed port 10. The surface of the powder spreading roller 13 is covered with tiny holes. The diameter of the holes is less than 1 μm (the maximum diameter of the holes is smaller than the minimum diameter of the powder), which can effectively prevent the powder from entering the inside of the powder spreading roller 13.

[0049] The discharge port is in an arc shape.

[0050] Two scrapers 11 are symmetrically arranged on both sides of the powder spreading roller 13. The scrapers 11 can move radially to adjust the thickness of each layer of the laid powder, so as to spread the powder evenly and flatly.

[0051] A powder suction device 12 is provided on the upper inner side of the powder spreading roller 13, and the powder suction device 12 sucks air into the inside so that the powder is evenly and firmly absorbed on the surface of the powder spreading roller 13. The powder suction device 12 is also used to apply an electric charge to the powder spreading roller 13 to further absorb the falling powder on the powder spreading roller 13.

[0052] A powder discharging device 14 is provided at the lower inner side of the powder spreading roller 13, and the powder discharging device 14 releases a charge opposite to the charge applied by the powder suction device 12, so as to spread the powder at the corresponding position on the powder spreading roller 13 on the printing platform below;

[0053] The printing platform is arranged at the center of the device. The printing platform is composed of a freely liftable lifting platform 5. The lifting platform 5 is driven up and down by a screw rod, and four guide rods are arranged around it to ensure the stability of the lifting of the platform.

[0054] The powder suction device 12 can release a certain Coulomb force to absorb the powder just coming out of the feed port 10 and place it on the top of the powder spreading roller 13 .

[0055] The powder spreading roller 13 has a certain amount of negative pressure inside. Under the effect of the negative pressure, the powder is further adsorbed on the powder spreading roller 13. Because the diameter of the holes on the surface of the powder spreading roller 13 is smaller than the powder particle size, the powder will not enter the inside of the powder spreading roller 13.

[0056] The lower surface of the powder lowering device 14 is arranged with a small nozzle, whose diameter is the same as the diameter of the hole on the surface of the powder spreading roller 13. When the place where powder is needed on the powder spreading roller 13 rotates to a relative position, the nozzle at the corresponding position of the powder lowering device 14 starts to work and sprays out a quantitative and constant pressure airflow, so that the powder below obtains enough force to resist the negative pressure suction, so as to be spread onto the lifting platform 5.

[0057] The rotation position of the powder spreading roller 13 and the opening position of the nozzle valve of the powder dispensing device 14 are uniformly controlled by the system.

[0058] Working principle or working method of the present invention:

[0059] like Figure 7-9 As shown, powder a enters the feeding port 10 on the right side of the powder spreading box 4 from the powder feeding funnel a 6 on the right side, and powder b enters the feeding port 10 on the right side of the powder spreading box 4 from the powder feeding funnel b on the left side. 7 enters the feed port 10 on the left side of the powder spreading box 4, and the powder flows downward from the feed port 10. Due to the action of the powder suction device 12, the powder suction device 12 applies Coulomb force to the powder. Combined with the negative pressure inside the powder spreading roller 13, the powder is evenly adsorbed on the outer surface of the powder spreading roller 13, and the powder spreading box 4 translates to the left, and the powder spreading roller 13 rotates counterclockwise. The scraper 11 scrapes the powder flat. When it moves to the corresponding position, the powder discharging device 14 starts to operate, and the nozzle at the corresponding position of the powder discharging device 14 starts to work, and sprays a quantitative and constant pressure airflow, so that the powder below obtains a force sufficient to resist the negative pressure suction, and the corresponding powder at the corresponding position is laid on the printing platform. The binder injection device 3 moves forward. When it moves to the corresponding position, the heating coil works, and the corresponding binder nozzle 16 drips out the binder. After being irradiated by the near-infrared lamp 17 at the rear, the binder and powder are further solidified. The lifting platform 5 moves down one layer, and the above process is repeated. After printing is completed, the model is taken out and put into the furnace for sintering. After a series of post-processing, the printing is completed.

Claims

1. A binder jetting additive manufacturing device based on a selective powder spreading mode, characterized in that: It comprises a housing (1), and a powder inlet (2) is arranged above the housing (1); An adhesive spraying device (3) is arranged inside the shell (1), and the adhesive spraying device (3) comprises a plurality of adhesive storage bins (15). A conduit is connected to the lower end of each of the plurality of adhesive storage bins (15), and an adhesive nozzle (16) is arranged at the lower end of each of the conduits.

2. The binder jetting additive manufacturing device based on the selective powder spreading mode according to claim 1, characterized in that: The adhesive spraying device (3) is fixed and moved by four guide rails connected to the inner wall of the housing (1); The two guide rails at the upper end are dust-free belt electric slides for controlling the movement of the injection device (3); The two guide rails on both sides are ball bearing guide rails.

3. The binder jetting additive manufacturing device based on the selective powder spreading mode according to claim 1, characterized in that: The adhesive nozzles (16) are arranged in three rows, and a small heating coil is arranged above each adhesive nozzle (16).

4. The binder jetting additive manufacturing device based on the selective powder spreading mode according to claim 3, characterized in that: A plurality of near-infrared lamps (17) are also arranged behind the adhesive nozzle (16), and the near-infrared lamps (17) are composed of two rows of near-infrared lamp beads.

5. The binder jetting additive manufacturing device based on the selective powder spreading mode according to claim 1, characterized in that: The powder inlet (2) comprises a powder feeding funnel a (6) and a powder feeding funnel b (7), The upper opening of the powder feeding funnel a (6) is square, and shrinks downward from large to small to form a square shape; The powder feeding funnel b (7) has the same shape as the powder feeding funnel a (6).

6. The binder jetting additive manufacturing device based on the selective powder spreading mode according to claim 5, characterized in that: A powder spreading box (4) is arranged inside the shell (1) and below the powder feeding funnel a (6) and the powder feeding funnel b (7), and two fixed and movable guide rails are arranged on the bottom side of the powder spreading box (4), and the guide rails are dust-free belt electric slides.

7. The binder jetting additive manufacturing device based on the selective powder spreading mode according to claim 6, characterized in that: The powder spreading box (4) comprises a powder spreading device a (8) and a powder spreading device b (9), two feed ports (10) are provided on the upper parts of the powder spreading device a (8) and the powder spreading device b (9), and a discharge port is provided at the opposite end of the feed port (10); A powder spreading roller (13) is arranged near the two discharge ports, scrapers (11) are arranged on both sides of the powder spreading roller (13), and a powder suction device (12) and a powder discharge device (14) are symmetrically arranged at the upper and lower parts of the powder spreading roller (13).

8. The binder jetting additive manufacturing device based on the selective powder spreading mode according to claim 7, characterized in that: The surface of the powder spreading roller (13) is covered with holes; The diameter of the pores is less than 1 μm.

9. The binder jetting additive manufacturing device based on the selective powder spreading mode according to claim 8, characterized in that: A nozzle is arranged on the lower surface of the powder dispensing device (14), and the diameter of the nozzle is the same as the diameter of the hole opened on the surface of the powder spreading roller (13); The valves of the powder spreading roller (13) and the nozzle of the powder dispensing device (14) are wirelessly connected to the monitoring system.

10. The binder jetting additive manufacturing device based on the selective powder spreading mode according to claim 6, characterized in that: A printing platform is also arranged at the center of the lower interior of the housing (1), and the printing platform is composed of a freely liftable lifting platform (5). The lifting platform (5) is driven up and down by a screw rod, and four guide rods are arranged around it to ensure the stable lifting of the platform.

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