A compact uniform air outlet structure of selective laser melting

Abstract

The application discloses a compact uniform air outlet structure of laser selective melting, and relates to the technical field of laser selective melting, which comprises an air pipe component, an air inlet for connecting a protective air flow, two binary tree type air guide pipes connected with the air inlet, a plurality of sub-flow channels, a multi-layer symmetrical tree structure, an outlet of each sub-flow channel of the lowermost layer, an air outlet area formed by the outlets, a guide plate arranged at a branch, and a rectifier pipe covering the air outlet area, wherein the rectifier pipe comprises a guide grid, a plurality of guide channels in the guide grid are parallel to each other, and the air flow of the air outlet area is changed into a flat air flow with consistent flow and flow rate on a forming plane. The application can make the flow and flow rate of the air flow at each position of the air outlet area tend to be uniform, and improve the forming quality and consistency of the forming quality at each processing position in the laser selective melting process.

Description

Technical Field

[0001] This invention relates to the field of laser selective melting technology, and in particular to a compact and uniform air outlet structure for laser selective melting. Background Technology

[0002] In selective laser melting (SLM) forming, the high-energy-density laser melting of metal powder generates a large amount of dust particles. These dust particles diffuse above the forming plane, reducing the laser energy reaching that plane. As processing time increases, the amount of dust particles adhering to the surface of the laser galvanometer's protective mirror increases, severely reducing the laser power reaching the forming plane.

[0003] Larger dust particles tend to fall onto the forming surface. When the laser energy is low, these large dust particles can adhere to the workpiece, causing unmelted areas and protrusions, affecting the forming quality and potentially leading to processing failure. Furthermore, uneven airflow can cause samples from the same batch to exhibit different properties at different forming locations, impacting the forming quality.

[0004] The protective airflow is often blown out from the circulating fan through a pipe of a certain diameter to the rectangular area of ​​the wide air outlet in the laser selective melting equipment. As the size of the forming plane increases, the air outlet structure is often large in volume and length so that the gas in the circular pipe can cover the entire width of the air outlet, which increases the bulkiness of the equipment. Moreover, it is difficult to ensure the uniformity of the protective airflow at each air outlet position, and it is difficult to ensure the consistency of the forming quality. Summary of the Invention

[0005] The present invention aims to at least partially solve one of the aforementioned technical problems in the prior art. To this end, embodiments of the present invention provide a compact and uniform air outlet structure for laser selective melting, addressing the problems of existing air outlet devices failing to guarantee uniform air outlet at all locations and having a large and insufficiently compact air outlet structure.

[0006] According to an embodiment of the present invention, a compact uniform air outlet structure for laser selective melting includes a duct component, the duct component including an air inlet for receiving protective airflow; two binary tree-shaped guide pipes connected to the airflow inlet, the binary tree-shaped guide pipes including multiple sub-channels, the binary tree-shaped guide pipes being a multi-layered symmetrical tree structure, the ends of the sub-channels of the upper layer leading to two sub-channels of the lower layer through bifurcations, thereby forming the binary tree-shaped guide pipes, the outlets of the lowermost sub-channels collectively forming an air outlet area, the bifurcations being provided with guide plates to uniformly distribute the airflow to the corresponding two sub-channels; and a rectifying pipe covering the air outlet area, the rectifying pipe including a guide grid, the guide grid having multiple parallel guide channels to transform the airflow in the air outlet area into a straight airflow with uniform flow rate and velocity on the forming plane.

[0007] In the above technical solution, the airflow inlet provides access for the protective airflow. After entering the duct component, the protective airflow enters the binary tree-shaped drainage pipe. The airflow then travels along the binary tree-shaped drainage pipe to the various guide channels of the downstream rectifying pipe. Because the binary tree-shaped drainage pipe has a symmetrical structure, the path length of the airflow to each position in the downstream rectifying pipe is consistent, resulting in good uniformity of airflow velocity. After the airflow is rectified by the guide grid of the rectifying pipe, the left-right and up-down components of the airflow are eliminated, resulting in a uniform airflow that moves parallel forward.

[0008] In an optional or preferred embodiment, the airflow inlet is provided with a baffle plate to evenly divide the airflow into the two binary tree-shaped drainage pipes. The baffle plate can solve the problem of inconsistent gas flow rates in the sub-channels of the left and right downstream branches of the binary tree-shaped drainage pipes caused by the airflow adhesion effect, so that the airflow flow rates entering the sub-channels of the left and right downstream branches tend to be consistent, and ultimately the airflow flow rates reaching the outlet area tend to be consistent.

[0009] In an optional or preferred embodiment, the binary tree-shaped drainage pipe has at least two layers, and each binary tree-shaped drainage pipe has at least two airflow outlets.

[0010] In an optional or preferred embodiment, at the bifurcation point, the angle between the two sub-channels of the next layer is defined as the bifurcation angle, which is greater than 0° and not greater than 180°. In a binary tree-shaped drainage pipe, the area of ​​the air outlet to be covered can be adjusted by adjusting the bifurcation angle, and the depth of the air outlet structure can be compressed. Therefore, a compact air outlet structure can be obtained according to the different installation space sizes of specific equipment.

[0011] In an optional or preferred embodiment, the length of the rectifying pipe is ≥5mm, the thickness of the flow guiding mesh is ≥0.2mm, and the cross-sectional area of ​​a single flow guiding channel is ≤5000mm². 2 .

[0012] In an optional or preferred embodiment, the solid portion of the flow guiding mesh accounts for no more than 20% of the cross-sectional area of ​​the rectifier pipe.

[0013] In an optional or preferred embodiment, the ratio of the air outlet length to the structural depth of the duct structure is greater than 1.

[0014] In an optional or preferred embodiment, the airflow inlet is connected to a pipe connection assembly, the pipe connection assembly including a protective airflow pipe, the protective airflow pipe being provided with a mounting flange for connection to the protective airflow source pipe.

[0015] Based on the above technical solution, the embodiments of the present invention have at least the following beneficial effects: In the above technical solution, the pipe for transmitting protective airflow is connected to the airflow inlet in the structure, and the airflow enters the binary tree-shaped guide channel; the binary tree-shaped guide channel can ensure that the airflow can reach the downstream rectifying pipe through the same path length, so that the airflow obtains a similar flow velocity when it reaches the rectifying pipe; the rectifying pipe is composed of a guide grid covering the entire air outlet area, which restricts the left and right and up and down components of the airflow, which is conducive to obtaining a parallel forward protective airflow. Therefore, the airflow in the pipe can be transformed into a straight airflow with a flow rate and velocity that tend to be consistent on the forming plane, which is beneficial to the removal of dust at various locations during the processing. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments;

[0017] Figure 1 This is a perspective view of an embodiment of the present invention;

[0018] Figure 2 This is a side view of an embodiment of the present invention;

[0019] Figure 3 yes Figure 2 Sectional view along the middle AA direction;

[0020] Figure 4 This is a rear view of an embodiment of the present invention. Detailed Implementation

[0021] This section will describe in detail specific embodiments of the present invention. Preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and overall technical solution of the present invention, but they should not be construed as limiting the scope of protection of the present invention.

[0022] 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.

[0023] In the description of this invention, "several" means one or more, "more than" 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.

[0024] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" 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.

[0025] The inventors discovered that the fumes generated during selective laser melting (SLM) significantly impact laser power and forming quality. If the airflow velocity in a localized area of ​​the forming region is too low, fumes cannot be promptly cleared from above the forming plane, resulting in a significant attenuation of laser power and consequently affecting forming quality. Furthermore, uneven airflow can cause samples from the same batch to exhibit different properties at different forming locations, affecting forming quality. Additionally, with the increasing size of SLM forming, converting the airflow range from a circular duct to a wider rectangle requires a bulky and lengthy conversion structure, increasing the overall size and weight of the equipment.

[0026] Therefore, the present invention provides a compact and uniform air outlet structure for laser selective melting, which makes the air outlet structure shorter when the airflow transitions from the circular tube to the wider air outlet, and can ensure the uniformity of the airflow flow rate and velocity.

[0027] Reference Figures 1 to 4 A compact, uniform air outlet structure for laser selective melting is presented, including a duct component 100. The duct component 100 includes an airflow inlet 111, a binary tree-shaped drainage pipe 120, and a rectifier pipe 130.

[0028] The airflow inlet 111 is used for the access of protective airflow. In one embodiment of the present invention, the airflow inlet 111 is connected to a pipe connection assembly 200, which includes a protective airflow pipe 211. The protective airflow pipe 211 is provided with a mounting flange 212 for connection to the protective airflow source pipe.

[0029] In this embodiment, two binary tree-shaped drainage pipes 120 are provided, both of which are connected to the airflow inlet 111. Preferably, the airflow inlet 111 is provided with a baffle plate 112 to evenly divide the airflow from the airflow inlet 111 into the two binary tree-shaped drainage pipes 120.

[0030] Specifically, the binary tree-shaped drainage duct 120 includes multiple sub-channels 121. The binary tree-shaped drainage duct 120 has a multi-layered symmetrical tree structure. The ends of the sub-channels 121 in the upper layer branch off at bifurcations 122 to form two sub-channels 121 in the lower layer, thus forming the binary tree-shaped drainage duct 120. The outlets of the bottommost sub-channels 121 collectively form an air outlet area. Preferably, the binary tree-shaped drainage duct 120 has at least two layers, and each binary tree-shaped drainage duct 120 has at least two airflow outlets. In this embodiment, referring to... Figure 3 The depth of the binary tree-shaped drainage pipe 120 is 5, that is, the number of layers is 5. At this time, the number of airflow outlets of a single binary tree-shaped drainage pipe 120 is 16, and the total number of airflow outlets in the air outlet area is 32.

[0031] In addition, a guide plate 123 is provided at the bifurcation point 122 to evenly distribute the airflow to the corresponding two sub-channels 121. Specifically, the guide plate 123 is positioned towards the upper-level sub-channel 121. Due to the airflow adhesion effect, the airflow flow rate of the protective airflow entering the downstream sub-channels 121 from the bifurcation point 122 of the binary tree-shaped diversion pipe is not consistent. By setting the guide plate 123, the airflow flow rate of the left and right downstream sub-channels 121 at each bifurcation point 122 tends to be consistent, which can solve the problem of inconsistent gas flow rate in the sub-channels of the left and right downstream branches of the binary tree-shaped diversion pipe caused by the airflow adhesion effect. This makes the airflow flow rate entering the sub-channels of the left and right downstream branches tend to be consistent, and ultimately makes the airflow flow rate reaching the outlet area consistent.

[0032] The rectifier duct 130 covers the air outlet area. The rectifier duct 130 includes a guide grid 131 with multiple parallel guide channels 132 to transform the airflow in the air outlet area into a straight airflow with uniform flow rate and velocity on the forming plane.

[0033] It is understood that the duct transmitting the protective airflow is connected to the airflow inlet 111 in the structure. In this embodiment, the protective airflow duct 211 is connected to the airflow inlet 111. The airflow inlet 111 is usually a circular duct. The protective airflow enters the duct component through the airflow inlet 111 and then enters the binary tree-shaped guide channel 120. The airflow enters the guide channels 132 of the downstream rectifying duct 130 along the binary tree-shaped guide channel 120. Since the binary tree-shaped guide channel 120 has a symmetrical structure, it can ensure that the airflow can reach the downstream rectifying duct through the same path length, so that the airflow obtains a similar flow velocity when it reaches the rectifying duct 130, and the flow velocity of the airflow exhibits good uniformity. The rectifying duct 130 is composed of a guide grid 131 covering the entire air outlet area, which restricts the left and right and up and down components of the airflow, which is conducive to obtaining a parallel forward protective airflow. After the airflow passes through the guide grid 131 of the rectifying duct 130, the left and right and up and down components of the airflow are eliminated, and a uniform airflow parallel forward can be obtained. In this way, the airflow in the pipeline can be transformed into a straight airflow with a uniform flow rate and velocity on the forming plane, which is beneficial for the removal of dust from various locations during the processing.

[0034] Reference Figure 3 In this embodiment, two binary tree-shaped drainage pipes 120 are provided, namely the left subtree and the right subtree. Of course, in the art, the left subtree and the right subtree can also be combined and understood as a binary tree-shaped duct component.

[0035] In the binary tree-shaped drainage pipe 120, the end of each sub-channel 121 leads to two sub-channels 121 of the next layer through a bifurcation 122. Specifically, the angle between the two sub-channels 121 of the next layer in the bifurcation 122 is defined as the bifurcation angle, which is greater than 0° and not greater than 180°.

[0036] In a binary tree-shaped drainage duct, the area of ​​the air outlet to be covered can be adjusted by changing the bifurcation angle, thus compressing the depth of the air outlet structure. It can be understood that the larger the bifurcation angle, the smaller the structural depth D of the air outlet structure. Figure 3 The structural depth is represented by D. The smaller the angle of the bifurcation, the greater the structural depth D of the air outlet structure. Therefore, those skilled in the art can understand this invention and obtain a compact air outlet structure according to the different installation space sizes of specific equipment. Of course, adjusting the structural depth D will also affect the air outlet length L of the duct component 100, such as... Figure 3 Let L represent the outlet length. In a preferred embodiment of the present invention, the ratio of the outlet length L of the duct component 100 to the structural depth D is greater than 1.

[0037] In some embodiments, the length of the rectifier duct 130 is ≥5mm, the thickness of the guide mesh 131 is ≥0.2mm, and the cross-sectional area of ​​a single guide channel 132 is ≤5000mm². 2 .

[0038] The solid portion of the flow guide grid 131 accounts for no more than 20% of the cross-sectional area of ​​the rectifying pipe 130. It can be understood that the total cross-sectional area of ​​all flow guide channels 132 accounts for more than 80% of the cross-sectional area of ​​the rectifying pipe 130. The purpose is to prevent the solid portion of the flow guide grid 131 from occupying too much area and affecting the area of ​​airflow outflow.

[0039] In application, the compact, uniform air outlet structure achieved by laser selective melting provided by this invention is manufactured using 3D printing methods with metal or non-metal materials. The duct component 100 is a one-piece printed component, and the airflow inlet 111, the binary tree-shaped drainage pipe 120, and the rectifying pipe 130 are all internal structures of the duct component 100.

[0040] 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. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A compact, uniform air outlet structure for laser selective melting, characterized in that: Includes duct components, the duct components include An airflow inlet for protective airflow access; Two binary tree-shaped diversion pipes are connected to the airflow inlet. Each binary tree-shaped diversion pipe includes multiple sub-channels and has a multi-layered symmetrical tree structure. The ends of the sub-channels in the upper layer branch off to the two sub-channels in the lower layer, thus forming the binary tree-shaped diversion pipe. The outlets of the bottommost sub-channels collectively form an air outlet area. A guide vane is provided at the branching point to evenly distribute the airflow to the corresponding two sub-channels. The binary tree-shaped diversion pipe has at least two layers, and each individual binary tree-shaped diversion pipe has at least two airflow outlets. A rectifier duct covers the air outlet area. The rectifier duct includes a flow guide grid with multiple parallel flow guide channels to transform the airflow in the air outlet area into a straight airflow with uniform flow rate and velocity on the forming plane. The length of the rectifier duct is ≥5mm, the thickness of the flow guide grid is ≥0.2mm, the cross-sectional area of ​​a single flow guide channel is ≤5000mm², and the solid portion of the flow guide grid accounts for no more than 20% of the cross-sectional area of ​​the rectifier duct.

2. The compact, uniform air outlet structure for laser selective melting according to claim 1, characterized in that: The airflow inlet is equipped with a baffle plate to evenly divide the airflow into the two binary tree-shaped drainage pipes.

3. The compact, uniform air outlet structure for laser selective melting according to claim 1, characterized in that: At the bifurcation point, the angle between the two sub-channels in the next layer is defined as the bifurcation angle, which is greater than 0° and not greater than 180°.

4. The compact, uniform air outlet structure for laser selective melting according to claim 1, characterized in that: The ratio of the outlet length to the structural depth of the duct component is greater than 1.

5. The compact, uniform air outlet structure for laser selective melting according to any one of claims 1 to 4, characterized in that: The airflow inlet is connected to a pipe connection assembly, which includes a protective airflow pipe. The protective airflow pipe is provided with an installation flange for connection to the protective airflow source pipe.

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