Continuous conveying device based on multi-material in-situ powder mixing

Abstract

The present invention discloses a continuous conveying device based on in-situ powder mixing of multiple materials. The device of the present invention includes multiple powder bins, powder mixing bins and transfer powder bins; the powder bins are used to store powder materials, and the compositions of the powder materials stored in the multiple powder bins are different; the powder outlets of the multiple powder bins are connected to the inlet of the powder mixing bin through a powder conveying pipeline, and the powder outlets of the multiple powder bins are respectively provided with adjustment devices; the powder mixing bin has a built-in stirring blade to quickly and evenly mix a variety of powder materials; the outlet of the powder mixing bin is interconnected with the inlet of the transfer powder bin, and the mixed powder will be conveyed to the transfer powder bin; the outlet of the transfer powder bin conveys the mixed powder to the cylinder body or nozzle of the additive manufacturing equipment through a single conveying pipeline for additive manufacturing. The present invention adopts a single nozzle to realize multi-material additive manufacturing. Compared with the multi-nozzle forming process, the space occupied in the forming bin is small and the operation flexibility is high.

Description

Technical Field

[0001] The present invention belongs to the technical field of additive manufacturing, and in particular relates to a continuous conveying device based on in-situ powder mixing of multiple materials. Background Art

[0002] Gradient materials are widely used in advanced manufacturing fields such as aviation, aerospace, and nuclear industry because they can give full play to the performance advantages of multiple materials and achieve special comprehensive properties that cannot be matched by a single homogeneous material. In recent years, the gradient material forming method developed based on additive manufacturing technology has been highly valued by the industry and academia because it can realize the rapid free forming of complex components and form a dense metallurgical bond between different materials. However, in the process of gradient material additive manufacturing, the switching between different materials and the cross-contamination between different materials have always been the key issues that hinder the technology from being applied to a wider range of fields. To solve the above problems, researchers usually use multiple material delivery nozzles to allow different nozzles to feed different materials to achieve multi-material forming; or use a multi-channel powder feeder to feed materials of different proportions to the same nozzle, and change the material feeding rate of the powder feeder to achieve multi-material additive manufacturing. However, the above methods still face some problems, such as the use of multiple nozzles, the difficulty of nozzle integration, and the space occupied; and in the multi-channel powder feeding process, the powders of different materials are only simply and briefly mixed in the conveying pipe / nozzle or molten pool, and it is difficult to ensure the mixing uniformity of materials of different proportions. Therefore, developing a continuous additive manufacturing method of gradient materials that can evenly mix multiple materials in arbitrary proportions through a single nozzle is a key issue that needs to be solved urgently. Summary of the invention

[0003] In order to solve the technical problems existing in the prior art, the present invention provides a continuous conveying device based on multi-material in-situ powder mixing. The present invention provides a powder mixing bin to quickly and evenly mix materials of different proportions, thereby improving the uniformity of powder mixing. Before the powder is fed into the nozzle, there is only one powder conveying pipeline (i.e., the powder conveying pipeline connected to the powder outlet of the transfer powder bin), so that multi-material additive manufacturing can be achieved using a single nozzle.

[0004] The present invention is achieved through the following technical solutions:

[0005] A continuous conveying device based on in-situ powder mixing of multiple materials, the conveying device comprising a plurality of powder bins, a powder mixing bin and a powder transfer bin;

[0006] The powder bins are used to store powder materials, and the powder materials stored in the plurality of powder bins have different compositions;

[0007] The powder outlets of the plurality of powder bins are connected to the inlet of the powder mixing bin through a powder conveying pipeline, and the powder outlets of the plurality of powder bins are respectively provided with an adjusting device;

[0008] The outlet of the powder mixing bin is connected to the inlet of the transfer powder bin; after the powder mixing bin quickly and evenly mixes a variety of powder materials, the mixed powder is transported to the transfer powder bin; the transfer powder bin transports the mixed powder to the cylinder or nozzle of the additive manufacturing equipment for additive manufacturing.

[0009] The present invention adopts an airflow driving method to drive the transmission of powders, and the inert gas can also prevent the powders from being oxidized.

[0010] Preferably, the device of the present invention further comprises an inert gas storage box;

[0011] The inert gas storage box is connected to the air inlets of the plurality of powder bins; and a switch device is respectively provided on the connecting pipes between the inert gas storage box and the air inlets of the plurality of powder bins;

[0012] The inert gas storage box is used to provide airflow to drive the transportation of the powder stored in the plurality of powder silos.

[0013] The present invention also introduces inert gas into the powder mixing bin to prevent oxidation of the powder. At the same time, after the powder is evenly mixed and transported to the transfer powder bin, the air flow rate at the air inlet can be increased to blow away the powder remaining on the inner wall of the powder mixing bin through the high-speed airflow to prevent cross-contamination of powders with different ratios.

[0014] Preferably, the powder mixing bin of the present invention has an air inlet and an air outlet;

[0015] The air inlet of the powder mixing bin is connected to the inert gas storage box, and a first control switch is provided on the connecting pipe between the powder mixing bin and the inert gas storage box; the air outlet of the powder mixing bin is provided with a third control switch.

[0016] The present invention also introduces inert gas into the transfer powder bin. When one ratio of material is delivered, the air flow rate at the air inlet is increased, and the high-speed air flow is used to blow away the residual powder in the transfer powder bin to prevent cross-contamination of powders of different ratios.

[0017] Preferably, the transfer powder bin of the present invention has an air inlet and an air outlet;

[0018] The air inlet of the transfer powder bin is connected to the inert gas storage box, and a second control switch is provided on the connecting pipe between the transfer powder bin and the inert gas storage box; the air outlet of the transfer powder bin is provided with a fifth control switch;

[0019] A fourth control switch is provided on the connecting pipeline between the transfer powder bin and the powder mixing bin.

[0020] Preferably, the powder mixing bin of the present invention adopts a spherical powder mixing cylinder with built-in stirring blades, and the stirring blades are used to turn over and stir powders of various materials.

[0021] The present invention also integrates the powder mixing bin and the powder transfer bin in the outer shell protection bin body to prevent the influence and pollution of the environment on the mixed powder.

[0022] Preferably, the present invention further comprises a shell protecting the warehouse body;

[0023] The powder mixing bin and the powder transfer bin are both arranged in the outer shell protection bin body.

[0024] Preferably, the regulating device of the present invention adopts a regulating valve.

[0025] On the other hand, the present invention also proposes a gradient material additive manufacturing system with in-situ powder mixing and continuous conveying. The system adopts the continuous conveying device described in the present invention to continuously convey the uniformly mixed powder to the cylinder or nozzle of the additive manufacturing equipment for additive manufacturing.

[0026] In addition, the present invention also proposes a gradient material additive manufacturing method with in-situ powder mixing and continuous conveying, which is implemented by using the continuous conveying device of the present invention and includes the following steps:

[0027] Step 1, adjusting the adjustment devices of the powder outlets of the powder silos to control the powder outlet speed of each powder silo, and conveying the powder with the expected composition ratio to the powder mixing silo;

[0028] Step 2: The powder mixing bin rotates rapidly to mix the different powders delivered, thereby achieving uniform mixing of powder materials with different components;

[0029] Step 3, after the powders are evenly mixed, the mixed powders in the powder mixing bin are transported to the transfer powder bin;

[0030] Step 4: The mixed powder in the transfer powder bin is transported to the cylinder or nozzle of the additive manufacturing equipment for additive manufacturing.

[0031] The present invention has the following advantages and beneficial effects:

[0032] 1. The present invention quickly mixes materials of different proportions on site through the rapid rotation of the spherical powder mixing bin, which reduces the process steps and saves time costs compared to traditional off-line mixing. At the same time, the powder mixing uniformity can be quickly improved by flipping and stirring the blades in the powder mixing bin. Compared with the conventional simple and short-time powder mixing in the powder conveying path / nozzle or the molten pool, the powder mixing uniformity is significantly improved.

[0033] 2. The present invention provides air inlets and air outlets in both the powder mixing bin and the powder transfer bin, and high-speed airflow can be used to quickly remove residual powder, thereby avoiding cross contamination between materials with different ratios.

[0034] 3. The continuous conveying device designed in the present invention has only one powder conveying pipeline before the powder is fed into the nozzle, so it can use a single nozzle to achieve multi-material additive manufacturing. Compared with the multi-nozzle forming process, it occupies less space in the forming chamber and has high operational flexibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0036] Figure 1 It is a schematic diagram of the conveying device principle of the present invention.

[0037] Marks and corresponding parts names in the attached drawings:

[0038] 1-first regulating valve, 2-second regulating valve, 3-third regulating valve, 4-first powder conveying pipeline, 5-powder mixing bin, 6-inert gas storage box, 7-gas conveying pipeline, 8-outer shell protecting bin body, 9-powder channel, 10-second powder conveying pipeline. DETAILED DESCRIPTION

[0039] Hereinafter, the term "include" or "may include" used in various embodiments of the present invention indicates the presence of the invented function, operation or element, and does not limit the addition of one or more functions, operations or elements. In addition, as used in various embodiments of the present invention, the terms "include", "have" and their cognates are intended only to indicate specific features, numbers, steps, operations, elements, components or combinations of the foregoing items, and should not be understood as first excluding the presence of one or more other features, numbers, steps, operations, elements, components or combinations of the foregoing items or the possibility of adding one or more features, numbers, steps, operations, elements, components or combinations of the foregoing items.

[0040] In various embodiments of the present invention, the expression "or" or "at least one of A or / and B" includes any combination or all combinations of the words listed at the same time. For example, the expression "A or B" or "at least one of A or / and B" may include A, may include B, or may include both A and B.

[0041] The expressions (such as "first", "second", etc.) used in various embodiments of the present invention may modify the various constituent elements in various embodiments, but may not limit the corresponding constituent elements. For example, the above expressions do not limit the order and / or importance of the elements. The above expressions are only used for the purpose of distinguishing an element from other elements. For example, the first user device and the second user device indicate different user devices, although both are user devices. For example, without departing from the scope of various embodiments of the present invention, the first element may be referred to as the second element, and similarly, the second element may also be referred to as the first element.

[0042] It should be noted that if it is described that one component element is “connected” to another component element, the first component element may be directly connected to the second component element, and a third component element may be “connected” between the first component element and the second component element. Conversely, when one component element is “directly connected” to another component element, it can be understood that there is no third component element between the first component element and the second component element.

[0043] The terms used in various embodiments of the present invention are only used for the purpose of describing specific embodiments and are not intended to limit various embodiments of the present invention. As used herein, the singular form is intended to also include the plural form, unless the context clearly indicates otherwise. Unless otherwise limited, all terms used here (including technical terms and scientific terms) have the same meaning as the meaning generally understood by those of ordinary skill in the art to which the various embodiments of the present invention belong. The terms (such as the terms defined in the dictionary generally used) will be interpreted as having the same meaning as the contextual meaning in the relevant technical field and will not be interpreted as having an idealized meaning or an overly formal meaning, unless clearly defined in various embodiments of the present invention.

[0044] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0045] Example 1

[0046] Compared with the existing multi-material additive manufacturing technology that has simple, short-term powder mixing in the powder conveying path / nozzle or molten pool and poor powder mixing uniformity, this embodiment proposes a continuous conveying device based on in-situ powder mixing of multiple materials. Before the powder enters the nozzle, the continuous conveying device has only one powder conveying pipeline. Therefore, a single nozzle can be used to achieve multi-material additive manufacturing. Compared with the multi-nozzle forming process, the space occupied in the forming chamber is small and the operating flexibility is high.

[0047] Specific as Figure 1As shown, the continuous conveying device of this embodiment includes: a plurality of powder bins, a powder mixing bin and a powder transfer bin;

[0048] This embodiment uses three powder bins, namely powder bin A, powder bin B and powder bin C;

[0049] The three powder silos are all used to store powder materials, and the compositions of the powder materials stored in the three powder silos are different;

[0050] The powder outlets of the three powder silos are connected to the inlet of the powder mixing silo 5 through the first powder conveying pipeline 4, and the powder outlet of the powder silo A is provided with a first regulating valve 1, the powder outlet of the powder silo B is provided with a second regulating valve 2, and the powder outlet of the powder silo C is provided with a third regulating valve 3;

[0051] The powder outlet of the powder mixing bin 5 is connected to the powder inlet of the transfer powder bin through a powder channel 9; after the powder mixing bin 5 quickly and evenly mixes a variety of powder materials, the mixed powder is transported to the transfer powder bin; the transfer powder bin transports the mixed powder to the cylinder or nozzle of the additive manufacturing equipment for additive manufacturing.

[0052] This embodiment uses airflow drive to drive the transmission of powders, and the inert gas can also prevent the powders from being oxidized.

[0053] like Figure 1 As shown, the device of this embodiment further comprises an inert gas storage box 6 .

[0054] The inert gas storage box 6 is connected to the air inlets of the three powder bins through a gas delivery pipeline; and a switch device K1 is provided on the connecting pipeline between the inert gas storage box 6 and the air inlet of the powder bin A, a switch device K2 is provided on the connecting pipeline between the inert gas storage box 6 and the air inlet of the powder bin B, and a switch device K3 is provided on the connecting pipeline between the inert gas storage box 6 and the air inlet of the powder bin C;

[0055] The inert gas storage box 6 is used to provide airflow to drive the transportation of powder stored in multiple powder silos.

[0056] The powder mixing bin 5 of this embodiment has an air inlet and an air outlet;

[0057] The air inlet of the powder mixing bin 5 is connected to the inert gas storage box 6 through a gas delivery pipeline, and a first control switch K4 is provided on the gas delivery pipeline between the powder mixing bin 5 and the inert gas storage box 6; the air outlet of the powder mixing bin 5 is provided with a third control switch K6;

[0058] The transfer powder bin of this embodiment has an air inlet and an air outlet;

[0059] The air inlet of the transfer powder bin is connected to the inert gas storage box 6 through a gas delivery pipeline, and a second control switch K5 is provided on the gas delivery pipeline between the transfer powder bin and the inert gas storage box 6; the air outlet of the transfer powder bin is provided with a fifth control switch K8;

[0060] A fourth control switch K7 is provided on the connecting pipeline between the transfer powder bin and the powder mixing bin.

[0061] Before mixing the powder, first open the air inlet switch K4 to allow inert gas to flow into the powder mixing bin to prevent oxidation of the powder. At the same time, after the powder is mixed and transported to the transfer powder bin, close the powder hose switch K7, open the air outlet switch K6, and increase the air inlet air flow rate to blow away the powder remaining on the inner wall of the powder mixing bin through high-speed airflow to prevent cross-contamination of powders with different ratios.

[0062] In the transfer powder bin, when one ratio of material is delivered, open the air outlet switch K8 and increase the air inlet air flow rate to blow away the residual powder in the transfer powder bin through high-speed airflow to prevent cross-contamination of powders of different ratios.

[0063] The powder mixing bin of the present embodiment adopts a spherical powder mixing cylinder with built-in stirring blades. During the powder mixing process, the powder mixing bin rotates rapidly, and the blades flip and stir the powder, thereby achieving rapid and uniform mixing of multiple materials.

[0064] In this embodiment, the powder mixing bin and the powder transfer bin are integrated in the outer shell protection bin body 8 to prevent the influence and pollution of the environment on the mixed powder.

[0065] The working principle of the continuous conveying device based on multi-material in-situ powder mixing of this embodiment is as follows:

[0066] An adjusting device is provided for adjusting the powder outlets of the plurality of powder silos to control the powder outlet speed of each powder silo, and the powder with the expected composition ratio is delivered to the powder mixing silo; the powder mixing silo rotates rapidly to mix the different powders delivered, so as to achieve uniform mixing of powder materials with different components; after the powders are uniformly mixed, the powders in the powder mixing silo are delivered to the transfer powder silo; the mixed powders in the transfer powder silo are delivered to the cylinder or nozzle of the additive manufacturing equipment for additive manufacturing.

[0067] Example 2

[0068] Based on the above-mentioned embodiment 1, this embodiment also proposes a gradient material additive manufacturing system with in-situ powder mixing and continuous conveying. The system adopts the continuous conveying device of the above-mentioned embodiment 1 to continuously convey the uniformly mixed powder to the cylinder or nozzle of the additive manufacturing equipment for additive manufacturing.

[0069] Example 3

[0070] Based on the above-mentioned embodiment 1, this embodiment further proposes a gradient material additive manufacturing method with in-situ powder mixing and continuous conveying. The method is implemented by the continuous conveying device of the present invention. The method of this embodiment includes the following steps:

[0071] Step 1: Place powder materials of different ingredients in powder bin A, powder bin B and powder bin C respectively;

[0072] Step 2: Open the powder pipe switches K1, K2 and K3, and adjust the speed of the powder outlet valve of the powder bin (1, 2, 3) to control the powder outlet speed and deliver the raw materials with the expected composition ratio to the powder mixing bin (8);

[0073] Step 3: The powder mixing bin rotates quickly to mix the different powders delivered, so as to achieve uniform mixing of different component materials;

[0074] Step 4: After the powders are evenly mixed, turn on switch K7 to transport the mixed powders in the powder mixing bin to the transfer powder bin;

[0075] Step 5: The mixed powder in the transfer powder bin is transported to the cylinder or nozzle of the additive manufacturing equipment through the powder pipe 10 for additive manufacturing;

[0076] Step 6: Repeat steps 2 to 5 to achieve continuous additive manufacturing of materials with different ratios.

[0077] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A continuous conveying device based on multi-material in-situ powder mixing, characterized in that: The conveying device includes a plurality of powder bins, a powder mixing bin and a powder transfer bin; The powder bins are used to store powder materials, and the powder materials stored in the plurality of powder bins have different compositions; The powder outlets of the plurality of powder bins are connected to the inlet of the powder mixing bin through a powder conveying pipeline, and the powder outlets of the plurality of powder bins are respectively provided with an adjusting device; The outlet of the powder mixing bin is connected to the inlet of the transfer powder bin; after the powder mixing bin quickly and evenly mixes a variety of powder materials, the mixed powder is transported to the transfer powder bin; The transfer powder bin transports the mixed powder to the cylinder or nozzle of the additive manufacturing equipment for additive manufacturing; and also includes an inert gas storage box; The inert gas storage box is connected to the air inlets of the plurality of powder bins; and a switch device is respectively provided on the connecting pipes between the inert gas storage box and the air inlets of the plurality of powder bins; The inert gas storage box is used to provide airflow to drive the transportation of the powder stored in the plurality of powder silos; The powder mixing bin is provided with an air inlet and an air outlet; The air inlet of the powder mixing bin is connected to the inert gas storage box, and a first control switch is provided on the connecting pipe between the powder mixing bin and the inert gas storage box; the air outlet of the powder mixing bin is provided with a third control switch; the transfer powder bin has an air inlet and an air outlet; The air inlet of the transfer powder bin is connected to the inert gas storage box, and a second control switch is provided on the connecting pipe between the transfer powder bin and the inert gas storage box; the air outlet of the transfer powder bin is provided with a fifth control switch; A fourth control switch is provided on the connecting pipeline between the transfer powder bin and the powder mixing bin.

2. The continuous conveying device based on multi-material in-situ powder mixing according to claim 1 is characterized in that: The powder mixing bin adopts a spherical powder mixing cylinder with built-in stirring blades, and the stirring blades are used to turn over and stir powders of various materials.

3. The continuous conveying device based on multi-material in-situ powder mixing according to claim 1 is characterized in that: Also includes a shell protecting the warehouse body; The powder mixing bin and the powder transfer bin are both arranged in the outer shell protection bin body.

4. The continuous conveying device based on multi-material in-situ powder mixing according to claim 1 is characterized in that: The regulating device adopts a regulating valve.

5. Gradient material additive manufacturing system with in-situ powder mixing and continuous conveying, characterized in that: The system uses the continuous conveying device as described in any one of claims 1 to 4 to continuously convey the uniformly mixed powder to the cylinder or nozzle of the additive manufacturing equipment for additive manufacturing.

6. A gradient material additive manufacturing method with in-situ powder mixing and continuous conveying, characterized in that: The method is implemented using the continuous conveying device according to any one of claims 1 to 4, comprising the following steps: Step 1, adjusting the adjustment devices of the powder outlets of the powder silos to control the powder outlet speed of each powder silo, and conveying the powder with the expected composition ratio to the powder mixing silo; Step 2: The powder mixing bin rotates rapidly to mix the different powders delivered, thereby achieving uniform mixing of powder materials with different components; Step 3, after the powders are evenly mixed, the mixed powders in the powder mixing bin are transported to the transfer powder bin; Step 4: The mixed powder in the transfer powder bin is transported to the cylinder or nozzle of the additive manufacturing equipment for additive manufacturing.

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