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CN-122007453-A - Air inlet channel structure suitable for metal 3d printing equipment

CN122007453ACN 122007453 ACN122007453 ACN 122007453ACN-122007453-A

Abstract

The invention discloses an air inlet channel structure suitable for metal 3d printing equipment, which comprises an inlet section, a snake-shaped mixing pipe section and a rectifying section which are sequentially connected in series along the air flow direction. Wherein the serpentine mixed tube section is composed of a section of tubing which is bent a plurality of times, and the number of times of bending is not less than three. Preferably, a primary rectifying part and a secondary rectifying part are sequentially arranged in the rectifying section along the airflow direction. The serpentine mixing tube section promotes the generation of intense lateral momentum exchange and entrainment of the air flow within the tube cross-section by the dean vortex effect, thereby effectively homogenizing the air flow from the inlet and initially attenuating large scale turbulent pulsations. And then the airflow enters the rectifying section and is converted into a laminar flow or quasi-laminar flow wind field which is perpendicular to the air outlet surface (the air outlet surface is the outlet end section of the rectifying section), stable in flow and uniform in thickness through the rectifying section.

Inventors

  • Zhang Junang
  • PAN HAOXING
  • LI JUNFENG

Assignees

  • 上海云铸三维科技有限公司

Dates

Publication Date
20260512
Application Date
20260306

Claims (10)

  1. 1. The air inlet channel structure suitable for the metal 3d printing equipment is characterized by comprising an inlet section, a snake-shaped mixing pipe section and a rectifying section which are sequentially connected in series along the air flow direction, wherein the snake-shaped mixing pipe section is formed by a section of pipeline which is bent for multiple times, and the bending times are not less than three times.
  2. 2. The inlet structure for a metal 3d printing apparatus according to claim 1, wherein the serpentine mixing tube section is formed from a length of tubing exhibiting a continuous S-shaped curvature.
  3. 3. The inlet structure for a metal 3d printing apparatus of claim 1, wherein the bend radius of the tubing in the serpentine mixing tube segment is 10-50 mm.
  4. 4. The inlet duct structure for a metal 3d printing apparatus according to claim 1, wherein an inlet end of the inlet section is provided with a quick connect fitting.
  5. 5. The inlet structure of claim 1, wherein the inlet section comprises a circular tube section and a variation section, the inlet end of the circular tube section is the inlet end of the inlet section, the outlet end of the circular tube section is connected with the inlet end of the variation section, and the outlet end of the variation section is connected with the inlet end of the serpentine mixing tube section.
  6. 6. The air inlet channel structure suitable for the metal 3d printing equipment according to claim 1, wherein a primary rectifying part and a secondary rectifying part are sequentially arranged in the rectifying section along the air flow direction, and the primary rectifying part and the secondary rectifying part are separated by a certain distance along the air flow direction; the preliminary rectifying portion is configured to perform a depressurization process on the passing airflow.
  7. 7. The inlet duct structure adapted for a metal 3d printing apparatus according to claim 6, wherein the preliminary rectifying portion includes a primary grid; The aperture in the primary grid is 2-4 mm, and/or the porosity of the primary grid is 10% -30%.
  8. 8. The inlet duct structure for a metal 3d printing apparatus according to claim 6, wherein the secondary rectifying portion includes a secondary grid; The aperture in the secondary grid is 4-6 mm, and/or the porosity of the secondary grid is 30-70%.
  9. 9. The air inlet structure suitable for the metal 3d printing device according to claim 8, wherein the preliminary rectifying portion includes a primary grating, and the length of the holes of the secondary grating is 2 to 4 times the length of the holes of the primary grating.
  10. 10. The inlet structure for a metal 3d printing apparatus according to claim 6, wherein the certain distance between the primary rectifying portion and the secondary rectifying portion in the air flow direction is 40 to 60 mm.

Description

Air inlet channel structure suitable for metal 3d printing equipment Technical Field The invention belongs to the technical field of additive manufacturing, in particular relates to a wind field regulation and control technology of laser selective melting (SELECTIVE LASER MELTING, SLM) forming equipment, aims at optimizing wind field wind speed uniformity in a forming cabin, and particularly relates to an air inlet channel structure suitable for metal 3d printing equipment. Background With the large-scale application of the laser selective melting technology in the high-end manufacturing fields of aerospace, medical implants and the like, the influence of metal vapor, smoke dust and melt splashes generated by high-energy laser in the forming process on the forming quality is increasingly remarkable. Specifically, the problems of black smoke residue, splash behavior runaway and wind field uniformity deficiency are included. The problem of black smoke residue is that black smoke formed by condensing metal vapor can be deposited on the surface of a laser lens, so that optical transmittance is attenuated and the lens is corroded, and meanwhile, part of black smoke and splashes fall back to a powder bed for the second time, so that defects such as air holes, inclusions and the like are formed in the solidification process of a molten pool, and the compactness and fatigue life of a formed part are obviously reduced. The problem of uncontrolled behavior of splashes is that the metal droplets sprayed by the unstable molten pool randomly fall to an unmelted powder layer or a formed area under the guidance of non-directional airflow, and cause inter-layer unmelting, spheroidization defects and surface roughness deterioration. The problem of uniformity of the wind field is that the excessive standard deviation of the uniformity of wind speed distribution can cause insufficient airflow speed in a local area of a forming area and can not effectively remove smoke dust, and a high-speed area can disturb the stability of a molten pool and aggravate splashing. Disclosure of Invention The invention aims to provide an air inlet channel structure suitable for metal 3d printing equipment, so as to solve the problem of forming defects caused by insufficient air speed uniformity in large-format SLM equipment in the prior art. The technical scheme of the invention is as follows: The air inlet channel structure suitable for the metal 3d printing equipment comprises an inlet section, a snake-shaped mixing pipe section and a rectifying section which are sequentially connected in series along the air flow direction, wherein the snake-shaped mixing pipe section is formed by a section of pipeline which is bent for multiple times, and the bending times are not less than three times. In the air inlet structure suitable for the metal 3d printing equipment provided by a certain preferred embodiment, the serpentine mixed tube section is formed by a section of a pipeline which presents a continuous S-shaped bend. In the air inlet channel structure suitable for the metal 3d printing equipment provided by a certain preferred embodiment, the bending radius of the pipeline in the serpentine mixed pipe section is 10-50 mm. In the air inlet structure suitable for the metal 3d printing equipment provided by a certain preferred embodiment, the inlet end of the inlet section is provided with a quick connector. In the air inlet channel structure suitable for the metal 3d printing equipment provided by a certain preferred embodiment, the inlet section comprises a circular tube section and a change section, the inlet end of the circular tube section is the inlet end of the inlet section, the outlet end of the circular tube section is connected with the inlet end of the change section, and the outlet end of the change section is connected with the inlet end of the serpentine mixed tube section. In the air inlet channel structure suitable for the metal 3d printing equipment provided by a certain preferred embodiment, a primary rectifying part and a secondary rectifying part are sequentially arranged in the rectifying section along the air flow direction, and the primary rectifying part and the secondary rectifying part are separated by a certain distance along the air flow direction; the preliminary rectifying portion is configured to perform a depressurization process on the passing airflow. In the air inlet channel structure suitable for the metal 3d printing equipment provided by a certain preferred embodiment, the preliminary rectifying part comprises a first-stage grid; The aperture in the primary grid is 2-4 mm, and/or the porosity of the primary grid is 10% -30%. In the air inlet channel structure suitable for the metal 3d printing equipment provided by a certain preferred embodiment, the secondary rectifying part comprises a secondary grid; The aperture in the secondary grid is 4-6 mm, and/or the porosity of the secondary grid is 30-70%. In the air