An additive manufacturing device and its wind field structure

Abstract

An additive manufacturing device and its wind field structure, wherein the wind field structure includes at least one first intake pipe, two or more second intake pipes, a plurality of suction pipes and a fan. At least one first intake pipe is arranged in the central area at the top of the working chamber of the additive manufacturing device for inputting the gas output by the fan into the working chamber. Two or more second intake pipes are arranged around the first intake pipe for inputting the gas output by the fan into the working chamber. A plurality of suction pipes are arranged at the bottom of the working chamber and are sequentially distributed around the working plane of the additive manufacturing for sucking the gas in the working chamber and transporting it to the fan. The pipe orifice of the suction pipe for sucking gas is higher than the working plane to form a full-width annular circulating air flow above the working plane. The present invention forms a full-width annular circulating air flow above the working plane, thereby greatly improving the performance consistency of large-size printed workpieces.

Description

Technical Field

[0001] The present application relates to the technical field of additive manufacturing, and particularly to an additive manufacturing device and its wind field structure. Background Art

[0002] Additive manufacturing technology is an advanced manufacturing technology with distinct characteristics such as digital manufacturing, high flexibility and adaptability, direct CAD model drive, rapidity, and a rich variety of material types. Due to its unrestricted by the complexity of part shapes and the absence of any tooling and dies, its application scope is very wide. Selective Laser Melting (SLM) is one of the rapidly developing additive manufacturing technologies in recent years. It uses powder materials as raw materials and employs a laser to scan the cross-section of a three-dimensional entity layer by layer to complete prototype manufacturing. It is not restricted by the complexity of part shapes and does not require any tooling and dies, and has a wide application scope. The basic process of the selective laser melting process is as follows: The powder feeding device delivers a certain amount of powder to the working platform surface, and the powder spreading device spreads a layer of powder material evenly on the bottom plate of the forming cylinder or the upper surface of the already formed part. The laser galvanometer system controls the laser to scan the solid part of the powder layer according to the cross-sectional profile of this layer with an approximately constant spot size and beam energy, causing the powder to melt and bond with the already formed part below; when a cross-section is sintered, the working platform descends by the thickness of one layer, and the powder spreading device spreads a new layer of uniform and dense powder on it, and then conducts the scanning and sintering of the new cross-section. After several layers of scanning and superposition, the entire prototype manufacturing is completed.

[0003] In a selective laser melting device, the generation of spatter is inevitable, and these spatters will affect the performance of the formed workpiece. Therefore, during the forming process, it is necessary to form a protective air flow with good fluidity above the sintering area to carry the spatters generated during the melting process away from the forming area.

[0004] With the increasing demand for large-sized formed workpieces, the volume of the device will become larger and larger, and the drawbacks of the traditional combination of a single air blowing port and an air suction port are magnified. The increase in the forming area will cause a greater attenuation of the protective air flow generated by the traditional structure in the moving direction, resulting in either blowing away the working powder due to too high a wind speed or being unable to carry the generated spatters away from the working area due to too low a wind speed during the melting and forming process, thereby significantly reducing the consistency of the performance of the formed workpiece. In severe cases, it may lead to the disqualification and scrapping of the formed workpiece. Summary of the Invention

[0005] Based on this, in view of the above technical problems, it is necessary to provide an additive manufacturing device and its wind field structure that can form a full-width annular circulating air flow above the working plane, thereby improving the performance consistency of large-sized formed workpieces.

[0006] To achieve the above-mentioned objectives, the present invention provides a wind field structure of an additive manufacturing device, comprising at least one first air inlet duct, two or more second air inlet ducts, a plurality of air suction ducts and a fan, wherein the at least one first air inlet duct is arranged at the top center area of ​​the working chamber of the additive manufacturing device, and is used to input the gas output by the fan into the working chamber, and the two or more second air inlet ducts are arranged around the first air inlet duct as the center, and are used to input the gas output by the fan into the working chamber, and the plurality of air suction ducts are arranged at the bottom of the working chamber and are distributed in sequence around the working plane of the additive manufacturing, and are used to suck in the gas in the working chamber and transport it to the fan, and the pipe opening of the air suction duct for sucking in gas is higher than the working plane, so as to form a full-width annular circulating airflow above the working plane.

[0007] As a further preferred embodiment of the present invention, the pipe opening of the air intake duct for inhaling gas is 30 mm-100 mm higher than the working plane.

[0008] As a further preferred embodiment of the present invention, the cross section of one end of the air intake duct located in the working chamber is square, and the cross section of the other end is circular, and the square cross-sectional area is larger than the circular cross-sectional area, so that the air intake duct has a special-shaped structure.

[0009] As a further preferred embodiment of the present invention, the number of the first air intake duct is one or more. When the number of the first air intake duct is more than one, the multiple first air intake ducts are distributed in a circular shape or in an array shape.

[0010] As a further preferred embodiment of the present invention, the wind field structure also includes a main air inlet and a main air outlet, one end of the main air inlet is connected to the fan through an air blowing pipeline, and the other end is connected to the first air inlet pipeline through a first gas flow channel, and is connected to the second air inlet pipeline through a second gas flow channel, one end of the main air outlet collects gas sucked in by several intake pipelines through several pipelines, and the other end is connected to the fan through an intake pipeline.

[0011] As a further preferred embodiment of the present invention, the wind field structure also includes a diversion device arranged at the main air inlet, which is used to divert the airflow at the main air inlet and make the gas flow entering the first gas flow channel greater than the gas flow entering the second gas flow channel.

[0012] As a further preferred embodiment of the present invention, the wind farm structure further includes a filtering device, and the filtering device is arranged at any position of the air intake pipeline.

[0013] The present invention also provides an additive manufacturing device, comprising a working chamber, a powder spreading device, a forming cylinder, and a wind field structure of the additive manufacturing device described in any of the above items, wherein a through hole is provided in the bottom center area of ​​the working chamber, and the forming cylinder performs a lifting and lowering movement in the through hole to realize the forming of the workpiece to be printed on the working plane.

[0014] As a further preferred embodiment of the present invention, the additive manufacturing equipment also includes a moving device, and the plurality of air suction pipes are lifted and lowered by the moving device, so that when the powder spreading device is spreading powder, the plurality of air suction pipes are raised to make room for the powder spreading device.

[0015] As a further preferred embodiment of the present invention, the through hole and the forming cylinder are both matched in round or square shapes. The additive manufacturing equipment and its wind field structure of the present invention include at least one first air inlet duct, two or more second air inlet ducts, several air suction ducts and a fan. The at least one first air inlet duct is arranged in the top center area of ​​the working chamber of the additive manufacturing equipment, and is used to input the gas output by the fan into the working chamber. The two or more second air inlet ducts are arranged around the first air inlet duct as the center, and are used to input the gas output by the fan into the working chamber. The several air suction ducts are arranged at the bottom of the working chamber and are sequentially distributed around the working plane of the additive manufacturing, and are used to suck the gas in the working chamber and transport it to the fan. The pipe opening of the air suction duct for sucking gas is higher than the working plane, so as to form a full-width annular circulating airflow above the working plane, thereby avoiding the disadvantage that the quality of the workpiece to be printed is poor due to inconsistent wind fields in various areas of the working plane of the large-size forming cylinder. Therefore, the present invention forms a full-width annular circulating airflow above the working plane, thereby greatly improving the performance consistency of large-size printed workpieces, that is, improving the forming of the workpiece to be printed. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A three-dimensional view of the first embodiment of the additive manufacturing device of the present invention;

[0017] Figure 2 A wind field flow diagram of an embodiment of a wind field structure provided for an additive manufacturing device of the present invention;

[0018] Figure 3 for Figure 1 A top view of

[0019] Figure 4 for Figure 1 A partial stereogram of

[0020] Figure 5 A cross-sectional view of Embodiment 1 provided for the first air intake duct or the second air intake duct of the present invention;

[0021] Figure 6 Cross-sectional view of Embodiment 2 provided for the first intake pipe or the second intake pipe of the present invention;

[0022] Figure 7 Cross-sectional view of Embodiment 3 provided for the first intake pipe or the second intake pipe of the present invention;

[0023] Figure 8 Top view of Embodiment 2 provided for the additive manufacturing equipment of the present invention;

[0024] Figure 9 Top view of Embodiment 3 provided for the additive manufacturing equipment of the present invention;

[0025] Figure 10 Top view of Embodiment 4 provided for the additive manufacturing equipment of the present invention.

[0026] In the figure:

[0027] 1. Laser, 2. Working chamber, 3. First intake pipe, 4. Second intake pipe, 5. Suction pipe, 6. Fan, 7. Total intake port, 8. Total outlet port, 9. Substrate, 10. Blowing pipeline, 11. Suction pipeline, 12. First gas flow channel, 13. Second gas flow channel, 14. Through hole. Detailed implementation manners

[0028] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0029] As Figures 1 to 4As shown, the present invention provides a wind field structure of an additive manufacturing device, comprising at least one first air inlet duct 3, two or more second air inlet ducts 4, a plurality of air suction ducts 5 and a fan 6, wherein the at least one first air inlet duct 3 is arranged at the top center area of ​​the working chamber 2 of the additive manufacturing device, and is used to input the gas output through the fan 6 into the working chamber 2, so as to form an airflow F1 flowing from the top of the working chamber 2 to the bottom of the working chamber 2 in the working chamber 2, and the two or more second air inlet ducts 4 are arranged around the first air inlet duct 3 as the center, and are used to input the gas output through the fan 6 into the working chamber 2, so as to form an airflow F2 flowing from the top of the working chamber 2 to the bottom of the working chamber 2 in the working chamber 2, and the plurality of air suction ducts 5 are arranged at the bottom of the working chamber 2 and are sequentially distributed around the working plane of the additive manufacturing, and are used to inhale the gas in the working chamber 2 and transport it to the fan 6, and the pipe opening of the air suction duct 5 for inhaling gas is higher than the working plane, so as to form a full-width annular circulating airflow above the working plane. Several air intake ducts 5 can be arranged without gaps, that is, closely adjacent to each other, or they can be arranged at intervals. The working plane refers to the plane for molding the workpiece to be printed, which is generally located on the base plate 9 above the molding cylinder.

[0030] The wind farm structure also includes an air inlet 7 and an air outlet 8. One end of the air inlet 7 is connected to the fan 6 through a blowing pipeline 10, and the other end is connected to the first air inlet pipeline 3 through a first gas flow channel 12, and is connected to the second air inlet pipeline 4 through a second gas flow channel 13. One end of the air outlet 8 collects the gas sucked in by several air intake pipelines 5 through several pipelines, and the other end is connected to the fan 6 through an air intake pipeline 11. Among them, the gas entering the blowing pipeline 10 can be an inert gas, nitrogen, argon, etc., or a mixed gas of multiple inert gases. The fan 6 converts the energy of the gas entering the air intake pipeline 11, so that the gas leaving the fan 6 and entering the blowing pipeline 10 has a certain kinetic energy.

[0031] In order to provide a more uniform and suitable wind field for the working plane, preferably, the nozzle of the air intake duct 5 for inhaling gas is 30mm-100mm higher than the working plane. Of course, other parameters can also be set according to the printing material and the area of ​​the working plane, which is not limited here.

[0032] In order to facilitate the arrangement of the suction duct and to facilitate its matching with the suction pipe 11, preferably, the cross section of one end of the suction duct 5 located in the working chamber 2 is square, and the cross section of the other end is circular, and the cross section area of ​​the square is larger than the cross section area of ​​the circular, so that the suction duct 5 is a special-shaped structure. The special-shaped structure can be specifically referred to Figure 4 Of course, it can also be an approximate structure. It should be noted that in the specific implementation, the air suction duct can also be other structures, which are not limited here.

[0033] In specific implementation, there is one first intake pipe 3, as Figures 1 to 8 , and Figure 10 shown, or there can be multiple ones, as Figure 9 shown. The specific selection can be made according to the size of the working plane. For example, when the working plane is relatively small, it is preferably to use one first intake pipe 3, while when the working plane is relatively large, it is preferably to use multiple first intake pipes 3. And when there are multiple first intake pipes 3, the multiple first intake pipes 3 are distributed in a circular or array shape. Of course, they can also be distributed in other shapes. At this time, the second intake pipe 4 is arranged to surround the first intake pipe 3. That is to say, when the multiple first intake pipes 3 are distributed in a circular shape, most of the second intake pipe 4 can also be arranged outside the circle, and a small part can be arranged inside the first intake pipe 3. The number of the second intake pipes 4 can be an odd number or an even number, and an even number is preferred. The specific size of the second intake pipe 4 can be adjusted according to the number of the second intake pipes 4.

[0034] As Figures 5 - 7 shown, the first intake pipe 3 is preferably rectangular and trapezoidal, and the second intake pipe 4 is preferably parallelogram and trapezoidal.

[0035] Figure 8 The difference between the embodiment shown in Figure 3 and the embodiment shown in Figure 3 is that the number of the suction pipes 5 changes from 6 to 8, so a more uniform wind field can be obtained above the working plane.

[0036] Preferably, the wind field structure further includes a flow splitting device arranged at the total intake port 7 for splitting the airflow at the total intake port 7, that is, obtaining gases with different ratios. For example, the gas flow rate entering the first gas flow channel 12 is greater than the gas flow rate entering the second gas flow channel 13.

[0037] The plurality of suction pipes 5 are arranged at the bottom of the working chamber 2. During the forming process, the gas containing harmful impurity particles is taken away from the working chamber 2 via the suction pipes 5 and enters the suction pipeline 11 through the total outlet port 8. In order to enable the gas to circulate into the working chamber 2, the wind field structure further includes a filtering device. The filtering device is arranged at any position of the suction pipeline 11 (specifically, a suitable position can be selected according to the design requirements). In this way, after the gas with harmful impurity particles enters the filtering device, the harmful impurity particles carried by it can be absorbed by the filtering device, thereby ensuring the purity of the gas and enabling the gas to be recycled.

[0038] As Figure 1As shown in the figure, the present invention also provides an additive manufacturing device, which includes a working chamber 2, a powder spreading device, a forming cylinder, and the wind field structure of the additive manufacturing device described in any one of the above. A through hole 14 is provided in the central area at the bottom of the working chamber 2, and the forming cylinder moves up and down in the through hole 14 to form a workpiece to be printed on the working plane. It should be noted here that in addition to the above components, the additive manufacturing device also includes many components of the prior art, such as a laser 1, a scanning system, etc. Since the key protection of the present invention lies in the wind field structure, other components of the additive manufacturing device will not be introduced one by one.

[0039] Preferably, in order to facilitate the arrangement of the suction pipeline 5, the through hole 14 and the forming cylinder are circular and match each other. Similarly, the working plane is also preferably circular. Of course, in specific implementation, it can also be square, as Figure 10 shown. When the through hole 14 and the forming cylinder are square, the number of suction pipelines 5 is preferably 4; as Figure 8 and Figure 9 shown. When the through hole 14 and the forming cylinder are circular, the number of suction pipelines 5 is preferably 4 or more.

[0040] Further preferably, during the forming process of the additive manufacturing device, it is necessary for the powder spreading device to push the powder raw material back and forth on the working plane to supply the powder raw material. The additive manufacturing device further includes a moving device, and the plurality of suction pipelines 5 move up and down through the moving device. When the powder spreading device is spreading powder, the plurality of suction pipelines are raised to make room for the powder spreading device, that is, to avoid the work of the powder spreading device.

[0041] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0042] The above embodiments only represent several implementation manners of the present application. The description is relatively specific and detailed, but it cannot be understood as a limitation to the scope of the invention patent. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present application, several deformations and improvements can be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. An additive manufacturing device, characterized in that, It includes a working chamber, a powder spreading device, a forming cylinder, and a wind field structure. A through hole is provided in the central area at the bottom of the working chamber. The forming cylinder moves up and down in the through hole to form a workpiece to be printed on the working plane. The wind field structure includes at least one first air inlet pipe, more than two and an even number of second air inlet pipes, four or more suction pipes, and a fan. The at least one first air inlet pipe is arranged in the central area at the top of the working chamber of the additive manufacturing equipment for inputting the gas output by the fan into the working chamber. All the second air inlet pipes are arranged around the first air inlet pipe for inputting the gas output by the fan into the working chamber. The several suction pipes are arranged at the bottom of the working chamber and are sequentially distributed around the working plane of the additive manufacturing for sucking the gas in the working chamber and transporting it to the fan. The gas inlet nozzle of the suction pipe for sucking gas is higher than the working plane to form a full-width annular circulating air flow above the working plane. Among them, the additive manufacturing equipment further includes a moving device. The several suction pipes move up and down through the moving device so that when the powder spreading device is performing powder spreading work, the several suction pipes are raised to make room for the powder spreading device.

2. The additive manufacturing equipment according to claim 1, characterized in that The gas inlet nozzle of the suction pipe for sucking gas is 30 mm - 100 mm higher than the working plane.

3. The additive manufacturing device according to claim 1, characterized in that, The cross-section of one end of the suction pipe located in the working chamber is square, and the cross-section of the other end is circular, and the cross-sectional area of the square is larger than that of the circular, so that the suction pipe is a special-shaped structure.

4. The additive manufacturing equipment according to claim 1, characterized in that, The first air inlet pipe is one or multiple. When the first air inlet pipe is multiple, the multiple first air inlet pipes are distributed in a circular or array shape.

5. The additive manufacturing device according to any one of claims 1 to 4, characterized in that, The wind field structure further includes an air inlet header and an air outlet header. One end of the air inlet header is connected to the fan through a blow pipe, and the other end is respectively connected to the first air inlet pipe through a first gas flow channel and to the second air inlet pipe through a second gas flow channel. One end of the air outlet header collects the gas sucked by the several suction pipes through several pipelines, and the other end is connected to the fan through a suction pipe.

6. The additive manufacturing device according to claim 5, characterized in that, The wind field structure further includes a flow splitting device arranged at the air inlet header for splitting the air flow at the air inlet header and making the gas flow entering the first gas flow channel greater than the gas flow entering the second gas flow channel.

7. The additive manufacturing device according to claim 6, characterized in that, The wind field structure further includes a filtering device, and the filtering device is arranged at any position of the suction pipe.

8. The additive manufacturing device according to claim 7, characterized in that, The through hole and the forming cylinder are both circular or square and match each other.

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