A laser wire gas coaxial wire feeding spraying additive manufacturing device and additive manufacturing method

Abstract

This invention discloses a laser-air coaxial filament feeding and spraying additive manufacturing apparatus and method. The apparatus includes a nozzle with a collecting cavity and a filament feeding channel, a laser channel, and an air jet structure connected to the collecting cavity; an air inlet structure surrounding the air jet structure and connected to the filament feeding channel via a pipe; a filament protection tube installed in the filament feeding channel, the interior of which is used to transport filament, and the gap between the filament protection tube and the filament feeding channel is used to transport gas; and a laser generator emitting laser light into the laser channel. The output direction of the filament is the same as the airflow direction, thus only the laser focusing position needs to be adjusted. By placing the air inlet structure outside the air jet structure, when air jetting is required, the gas can first exchange heat with the air jet structure to cool it down, and then flow into the collecting cavity to spray out the molten filament. Compared to traditional structures, this method does not involve complex improvements but effectively cools the air jet structure.

Description

Technical Field

[0001] This invention relates to the field of laser spraying technology, and in particular to a laser filament coaxial feeding spraying additive manufacturing apparatus and additive manufacturing method. Background Technology

[0002] Laser spraying is a novel material surface modification and remanufacturing technology. It involves spraying special materials onto the surface of a substrate, using a high-energy laser beam to melt the material, and then using high-speed gas to atomize the molten material into particles, which are then accelerated and sprayed onto the original substrate surface to generate a new coating layer. This adds special properties to the original substrate that it did not originally have, and extends the life of the substrate itself.

[0003] Laser coating methods are categorized into pre-positioned and synchronous methods based on the material delivery method. The synchronous method can be further divided into powder feeding and wire feeding methods depending on the state of the material during synchronous feeding. Wire feeding offers higher material utilization than powder feeding, and the feeding process is easier to control, resulting in higher additive manufacturing precision and more uniform coating thickness. Therefore, it currently enjoys a higher market penetration rate.

[0004] Currently, laser coating equipment still faces challenges such as difficulty in melting the filament and unstable coating conditions. The key issue lies in achieving precise focusing of airflow, material, and laser light at a single point during laser coating. Furthermore, after prolonged operation, the nozzle is prone to deformation due to high temperatures, leading to unstable airflow and deviation in the material spray direction, ultimately affecting the final forming effect. Simply adding a cooling system to the nozzle would increase the complexity of the entire device, hindering production cost control and subsequent maintenance. Summary of the Invention

[0005] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the present invention proposes a laser filament coaxial feeding spraying additive manufacturing apparatus, which can focus the airflow, material and laser in the laser spraying process at a single point, and uses a simple structure to cool the nozzle.

[0006] The present invention also proposes an additive manufacturing method based on the above-mentioned laser filament coaxial feeding and spraying additive manufacturing device.

[0007] A laser filament-air coaxial filament feeding and spraying additive manufacturing apparatus according to a first aspect of the present invention comprises:

[0008] The nozzle has a collecting cavity and a wire feeding channel, a laser channel and an air jet structure connected to the collecting cavity;

[0009] An air intake structure is provided, which is arranged around the outside of the jet structure and is connected to the wire feeding channel via a pipe.

[0010] A wire protection tube is installed in the wire feeding channel. The interior of the wire protection tube is used to transport wire, and the gap between the wire protection tube and the wire feeding channel is used to transport gas.

[0011] A laser generator, which is connected to the laser channel and emits a laser therein;

[0012] In this system, the gas in the air intake structure can carry away the heat from the jet structure. The gas flows sequentially through the pipe and the wire feeding channel and then enters the collecting cavity in the same direction as the wire in the wire protection tube. The laser from the laser generator enters the collecting cavity and melts the wire. The airflow then ejects the melted wire to the jet structure.

[0013] The laser-air coaxial filament feeding and spraying additive manufacturing apparatus according to embodiments of the present invention has at least the following advantages: the output direction of the filament is the same as the airflow direction, so only the laser focusing position needs to be adjusted, which facilitates the control of the melting position of the filament; the air inlet structure is set outside the air jet structure, so when air jet is needed, the gas can first exchange heat with the air jet structure to cool it down, and then flow into the collecting cavity to spray out the molten filament. Compared with the traditional structure, no complicated improvements have been made, but the air jet structure can be cooled down effectively.

[0014] According to some embodiments of the present invention, the airflow direction in the intake structure is opposite to the airflow direction in the jet structure.

[0015] According to some embodiments of the present invention, two or more pipes are connected between the air intake structure and the wire feeding channel, and the pipes are distributed in a circumferential array around the wire feeding channel.

[0016] According to some embodiments of the present invention, the jetting structure is located on the extension line of the wire feeding channel, and the extension line of the laser channel intersects the extension line of the wire feeding channel in the collecting cavity.

[0017] According to some embodiments of the present invention, there are multiple laser channels and they are distributed in a circular array around the wire feeding channel.

[0018] According to some embodiments of the present invention, the wire protection tube is fixed to the center of the wire feeding channel by a support rod.

[0019] According to some embodiments of the present invention, there are multiple support rods that are distributed in a circumferential array around the wire protective tube.

[0020] According to some embodiments of the present invention, the jet structure is specifically a Laval structure, wherein the inner diameter of the jet structure gradually decreases and then gradually increases along the airflow direction therein.

[0021] According to some embodiments of the present invention, the laser filament coaxial feeding and spraying additive manufacturing apparatus further includes a filament feeding mechanism connected to the filament protection tube. The filament feeding mechanism includes two conveying rollers that together clamp the filament. The rotation of the conveying rollers can feed the filament into the filament protection tube.

[0022] According to a second aspect of the present invention, an additive manufacturing method based on the above-described laser filament coaxial feeding and spraying additive manufacturing apparatus includes the following steps:

[0023] Install the filament into the filament feeding mechanism and start the filament feeding mechanism to feed the filament into the filament protection tube;

[0024] Orient the output end of the jet structure toward the substrate to be processed;

[0025] Connect the air intake end of the air intake structure to the air storage tank;

[0026] The laser generator is activated, and the laser beam passes through the laser channel to the collecting cavity, melting the filament.

[0027] When the gas tank is opened, gas enters the collecting chamber through the air inlet structure, the pipe, and the wire feeding channel, and drives the molten wire into the jet structure.

[0028] The molten filament is sprayed onto the substrate surface under the influence of the airflow in the jet structure, thus completing the material coating.

[0029] The airflow in the intake structure continuously carries away the heat from the jet structure, thereby cooling the jet structure.

[0030] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0031] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0032] Figure 1 This is a cross-sectional view of a laser filament coaxial feeding spraying additive manufacturing apparatus according to a first aspect embodiment of the present invention;

[0033] Figure 2 for Figure 1 Cross-sectional view at point AA;

[0034] Figure 3 This is a schematic diagram of the airflow direction in the pipe 210 of the laser filament coaxial feeding spraying additive manufacturing apparatus according to the first aspect of the present invention;

[0035] Figure 4 for Figure 1 Cross-sectional view at point BB.

[0036] Reference numerals: 100-nozzle, 110-collecting cavity, 120-wire feeding channel, 130-laser channel, 140-jet structure, 200-air inlet structure, 210-pipe, 300-wire protection tube, 310-support rod, 400-laser generator, 500-wire feeding mechanism, 600-wire. Detailed Implementation

[0037] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0038] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0039] In the description of this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0040] In the description of this invention, unless otherwise explicitly defined, terms such as "setting," "installing," and "connecting" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0041] In the description of this invention, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0042] Currently, laser coating equipment still faces challenges such as difficulty in melting the filament and unstable coating conditions. The key issue lies in achieving precise focusing of airflow, material, and laser light at a single point during laser coating. Furthermore, after prolonged operation, the nozzle is prone to deformation due to high temperatures, leading to unstable airflow and deviation in the material spray direction, ultimately affecting the final forming effect. Simply adding a cooling system to the nozzle would increase the complexity of the entire device, hindering production cost control and subsequent maintenance.

[0043] In response, this application proposes a laser-air coaxial filament feeding and spraying additive manufacturing apparatus and method. In this apparatus, the output direction of the filament 600 is the same as the airflow direction, so only the laser focusing position needs to be adjusted to easily control the melting position of the filament. The air inlet structure 200 is set outside the air jet structure 140. When air jetting is required, the gas can first exchange heat with the air jet structure 140 to cool it down, and then flow into the collecting cavity 110 to spray out the molten filament. Compared with the traditional structure, no complicated improvements have been made, but the air jet structure can be cooled effectively.

[0044] Reference Figure 1 The laser-air coaxial filament feeding and spraying additive manufacturing apparatus in the first aspect of this application includes a nozzle 100, an air inlet structure 200, a filament protection tube 300, and a laser generator 400. The nozzle 100 is the main structure of this laser-air coaxial filament feeding and spraying additive manufacturing apparatus. The air inlet structure 200 guides gas into the nozzle 100 and also serves to exchange heat with the nozzle 100 for cooling. The filament protection tube 300 guides the filament 600 into the nozzle 100. The laser generator 400 emits laser light to melt the filament 600.

[0045] Specifically, the nozzle 100 has a collecting cavity 110 and a wire feeding channel 120, a laser channel 130, and a jet structure 140 connected to the collecting cavity 110. An air intake structure 200 surrounds the jet structure 140, enabling heat exchange and cooling of the jet structure 140 after external gas enters it. The air intake structure 200 is connected to the wire feeding channel 120 via a pipe 210, thereby guiding the gas into the wire feeding channel 120.

[0046] A wire protection tube 300 is installed in the wire feeding channel 120. The interior of the wire protection tube 300 is used to transport the wire 600, and the gap between the wire protection tube 300 and the wire feeding channel 120 is used to transport gas. The laser generator 400 is connected to the laser channel 130 and emits a laser into it. The laser is projected along the laser channel 130 into the collecting cavity 110 and melts the wire 600.

[0047] In this process, the gas in the air intake structure 200 can carry away the heat from the jet structure 140. The gas flows through the pipe 210 and the wire feeding channel 120 in sequence and enters the collecting cavity 110 in the same direction as the wire 600 in the wire protection tube 300. The laser from the laser generator 400 enters the collecting cavity 110 and melts the wire 600. The airflow ejects the melted wire 600 to the jet structure 140, and finally the jet structure 140 ejects the wire 600.

[0048] Specifically, the gas output to the air intake structure 200 in this application is an inert gas, including but not limited to argon and helium, used to drive the molten wire 600 to move, while preventing the gas from reacting or exploding at high temperatures.

[0049] Furthermore, the jet structure 140 is located on the extension line of the wire feeding channel 120, so that the airflow ejected from the wire feeding channel 120 can smoothly drive the molten wire into the jet structure 140 and eject it in accordance with the guidance of the channel inside the jet structure 140. The extension line of the laser channel 130 intersects the extension line of the wire feeding channel 120 in the collecting cavity 110, thereby ensuring that the laser and the wire 600 intersect in the collecting cavity 110.

[0050] Furthermore, referring to Figure 2 There are multiple laser channels 130, which are arranged in a circular array around the wire feeding channel 120. Each laser channel 130 is equipped with a laser generator 400, thereby using a multi-source structure to heat the wire 600.

[0051] Furthermore, two or more pipes 210 are connected between the air intake structure 200 and the wire feeding channel 120. The pipes 210 are arranged in a circumferential array around the wire feeding channel 120, so that airflow can be evenly delivered into the wire feeding channel 120 through multiple pipes 210. In this embodiment, there are two pipes 210. It is easy to understand that the number of pipes 210 can be increased or decreased according to the actual situation.

[0052] Furthermore, the airflow direction in the intake structure 200 is opposite to the airflow direction in the jet structure 140, thereby making the heat exchange between the two more efficient.

[0053] Specifically, refer to Figure 3 The pipe 210 is a "U" shaped pipe, which guides the airflow in the air intake structure 200 to the wire feeding channel 120, and makes the airflow direction consistent with the wire feeding direction.

[0054] Furthermore, the wire protection tube 300 is fixed to the center of the wire feeding channel 120 by the support rod 310, so that the wire 600 is located in the center of the airflow ejected from the wire feeding channel 120, which is conducive to the subsequent ejection of the wire 600 by the airflow.

[0055] Reference Figure 4 There are multiple support rods 310, which are arranged in a circular array around the wire protection tube 300, thereby providing stable support for the wire protection tube 300.

[0056] Optionally, the jet structure 140 is specifically a Laval structure, in which the inner diameter gradually decreases and then gradually increases along the airflow direction. This results in an increase in pressure and velocity when the airflow passes through the point of minimum inner diameter of the jet structure 140, facilitating accurate spraying onto the substrate surface. The Laval structure is existing technology, and its specific structure and working principle will not be described in detail here.

[0057] Furthermore, this laser filament coaxial feeding and spraying additive manufacturing apparatus also includes a filament feeding mechanism 500, which is connected to the filament protection tube 300. The filament feeding mechanism 500 includes two conveying rollers, which together clamp the filament 600. The rotation of the conveying rollers can feed the filament 600 into the filament protection tube 300.

[0058] An additive manufacturing method according to a second aspect of this application, based on the aforementioned laser filament coaxial feeding and spraying additive manufacturing apparatus, includes the following steps:

[0059] S100. Install the wire 600 into the wire feeding mechanism 500 and start the wire feeding mechanism 500 to feed the wire 600 into the wire protection tube 300;

[0060] S200. Orient the output end of the jet structure 140 toward the substrate to be processed;

[0061] S300. Connect the intake end of the intake structure 200 to the air storage tank;

[0062] S400. Start the laser generator 400. The laser beam passes through the laser channel 130 and irradiates the collecting cavity 110, and irradiates the wire 600 to melt it.

[0063] S500. Open the gas storage tank, and the gas enters the collection chamber 110 through the air intake structure 200, pipe 210, and wire feeding channel 120, and drives the molten wire 600 into the jet structure 140.

[0064] S600. The molten wire 600 is sprayed onto the surface of the substrate under the influence of the airflow in the jet structure 140, thus completing the material coating.

[0065] S700. The airflow in the intake structure 200 continuously carries away the heat from the jet structure 140, thereby cooling the jet structure 140.

[0066] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments, and various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof can be combined with each other unless otherwise specified.

Claims

1. A laser filament coaxial feeding and spraying additive manufacturing apparatus, characterized in that, include: The nozzle has a collecting cavity and a wire feeding channel, a laser channel and an air jet structure connected to the collecting cavity; An air intake structure is provided, which is arranged around the outside of the jet structure and is connected to the wire feeding channel via a pipe. A wire protection tube is installed in the wire feeding channel. The interior of the wire protection tube is used to transport wire, and the gap between the wire protection tube and the wire feeding channel is used to transport gas. A laser generator, which is connected to the laser channel and emits a laser therein; The gas in the air intake structure can carry away the heat of the jet structure. The gas flows through the pipe and the wire feeding channel in sequence and enters the collection cavity in the same direction as the wire in the wire protection tube. The laser of the laser generator enters the collection cavity and melts the wire. The airflow sprays the melted wire out to the jet structure. The airflow direction in the intake structure is opposite to the airflow direction in the jet structure; The jet structure is specifically a Laval structure, and the inner diameter of the jet structure gradually decreases and then gradually increases along the airflow direction therein.

2. The laser filament coaxial feeding and spraying additive manufacturing apparatus according to claim 1, characterized in that: The air intake structure is connected to the wire feeding channel by two or more pipes, which are arranged in a circular array around the wire feeding channel.

3. The laser filament coaxial feeding and spraying additive manufacturing apparatus according to claim 1, characterized in that: The jet structure is located on the extension line of the wire feeding channel, and the extension line of the laser channel intersects the extension line of the wire feeding channel in the collecting cavity.

4. The laser filament coaxial feeding and spraying additive manufacturing apparatus according to claim 3, characterized in that: The laser channels are multiple and arranged in a circular array around the wire feeding channel.

5. The laser filament coaxial feeding and spraying additive manufacturing apparatus according to claim 1, characterized in that: The wire protection tube is fixed to the center of the wire feeding channel by a support rod.

6. The laser filament coaxial feeding and spraying additive manufacturing apparatus according to claim 5, characterized in that: There are multiple support rods, which are arranged in a circumferential array around the wire protective tube.

7. The laser filament coaxial feeding and spraying additive manufacturing apparatus according to claim 1, characterized in that: The laser filament coaxial feeding and spraying additive manufacturing apparatus further includes a filament feeding mechanism connected to the filament protection tube. The filament feeding mechanism includes two conveying rollers that together hold the filament. The rotation of the conveying rollers can feed the filament into the filament protection tube.

8. An additive manufacturing method, based on the laser filament coaxial feeding and spraying additive manufacturing apparatus according to any one of claims 1 to 7, characterized in that, include: Install the filament into the filament feeding mechanism and start the filament feeding mechanism to feed the filament into the filament protection tube; Orient the output end of the jet structure toward the substrate to be processed; Connect the air intake end of the air intake structure to the air storage tank; The laser generator is activated, and the laser beam passes through the laser channel to the collecting cavity, melting the filament. When the gas tank is opened, gas enters the collecting chamber through the air inlet structure, the pipe, and the wire feeding channel, and drives the molten wire into the jet structure. The molten filament is sprayed onto the substrate surface under the influence of the airflow in the jet structure, thus completing the material coating. The airflow in the intake structure continuously carries away the heat from the jet structure, thereby cooling the jet structure.

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