阅读说明：本技术 一种吹除飞溅金属颗粒和烟尘的装置及其控制方法 (Device for blowing off splashing metal particles and smoke dust and control method thereof ) 是由 苏帅 曾刚 庞恩林 唐宝 于 2020-12-15 设计创作，主要内容包括：3D打印过程中,激光扫描金属粉末床会产生一些飞溅金属颗粒和烟尘。本发明提供了一种吹除飞溅金属颗粒和烟尘的装置及其控制方法,该装置包括刮刀、贯流风机、集粉槽、供粉缸、成型缸以及气体循环系统。风机安装在刮刀上,利用贯流风机提供的水平方向上均匀稳定的风场,吹除激光扫描金属粉末床过程中产生的飞溅金属颗粒和烟尘,防止金属颗粒落在激光扫描区域,影响本次激光扫描金属粉末熔池质量和下次刮刀铺粉效果；密度较大的颗粒落进集粉槽,密度较小的颗粒以及烟尘被抽进吸风口。(During 3D printing, laser scanning of the metal powder bed can generate some spattered metal particles and smoke. The invention provides a device for blowing off splashed metal particles and smoke dust and a control method thereof. The fan is arranged on the scraper, and the uniform and stable wind field in the horizontal direction provided by the cross-flow fan is utilized to blow off the splashed metal particles and smoke dust generated in the process of scanning the metal powder bed by laser, so that the metal particles are prevented from falling in a laser scanning area, and the quality of a metal powder molten pool in the laser scanning and the powder spreading effect of the scraper at the next time are influenced; the particles with higher density fall into the powder collecting groove, and the particles with lower density and the smoke dust are pumped into the air suction opening.)

1. A device for blowing off splashed metal particles and smoke dust is arranged at the upper part of a metal printing bin, and the metal printing bin is a sealed bin body;

the bottom of the metal printing bin is sequentially hung with a powder supply cylinder, a forming cylinder and a powder collecting cylinder which are provided with openings according to the working sequence, and the scraper moves back and forth among the openings of the powder supply cylinder, the forming cylinder and the powder collecting cylinder and is used for sequentially conveying metal powder in the powder supply cylinder to the forming cylinder and the powder collecting cylinder;

laser is projected to the right upper part of the forming cylinder from the upper part of the metal printing bin to locally melt metal particles;

the method is characterized in that: the device mainly comprises a gas circulation system and a cross-flow fan, wherein the gas circulation system is arranged on the side wall of the metal printing bin and comprises at least one blowing port and one suction port, and is used for blowing metal particles floating in the metal printing bin out of the metal printing bin according to the arrangement direction of the powder supply cylinder, the forming cylinder and the powder collection cylinder; the cross-flow fan is arranged on the scraper, an air outlet of the cross-flow fan is parallel to the movement plane of the scraper, and the air outlet direction of the cross-flow fan is basically consistent with the air flow movement direction of the air circulation system.

2. The apparatus for blowing off the splattered metal particles and the soot according to claim 1, wherein: the gas circulation system comprises a gas circulation system blowing opening arranged on one side of the powder supply cylinder and a gas circulation system air suction opening arranged on one side of the powder collection cylinder, and when the gas circulation system blowing opening blows air with a certain flow speed and the gas circulation system air suction opening generates negative pressure air suction with a certain pressure, a one-way cleaning air channel is formed in the metal printing bin.

3. The apparatus for blowing off the splattered metal particles and the soot according to claim 2, wherein: the bottom of the metal printing bin is used as a reference, and the height of the air blowing opening of the air circulation system is higher than that of the air suction opening of the air circulation system.

4. The apparatus for blowing off the splattered metal particles and the soot according to claim 2 or 3, characterized in that: the bottom of the metal printing bin is used as a reference, and the height of an air outlet of the cross flow fan is basically consistent with that of an air suction inlet of the air circulation system.

5. The apparatus for blowing off the splattered metal particles and the soot according to claim 4, wherein: the length of the cross-flow fan is not less than the length of the molding area.

6. The apparatus for blowing off the splattered metal particles and the soot according to claim 2 or 3, characterized in that: the gas blown out by the gas circulation system and the cross-flow fan is inert gas with certain cleanliness.

7. The apparatus for blowing off the splattered metal particles and the soot according to claim 2 or 3, characterized in that: the air circulation system and the air output of the cross flow fan can be adjusted by respective control systems.

8. A control method for blowing off splashed metal particles and smoke dust is characterized by comprising the following steps: mainly comprises the following steps: the preparation method comprises the following steps: a scraper scrapes a certain amount of metal powder from the powder supply cylinder and spreads the metal powder on the surface of the opening of the forming cylinder, the excessive amount of metal powder is pushed to the powder collecting groove, and the cross-flow fan is driven by the scraper to run between the forming cylinder and the powder supply cylinder;

starting the cleaning system: the gas circulation system and the cross flow fan are simultaneously started, and the gas circulation system and the cross flow fan blow floating metal particles and laser-burned smoke dust to the powder collecting groove and the air suction port of the gas circulation system;

laser printing: the laser equipment reflects laser to metal particles on a preset area on the surface of the forming cylinder to complete the melting work of a layer of metal powder;

the cleaning system was shut down and the three steps described above were repeated.

9. The control method of blowing off the splashed metal particles and the smoke according to claim 5, wherein: in the preparation step, the supporting base of the powder supply cylinder rises to a certain height to ensure that a certain amount of metal particles are higher than the bottom surface of the metal printing bin, the supporting base of the forming cylinder falls to a certain height to ensure that the metal burning surface is lower than the opening of the forming cylinder, and the scraper pushes the metal particles higher than the opening part of the powder supply cylinder to the forming cylinder and ensures that the height of the metal powder layer is flush with the opening of the forming cylinder.

The technical field is as follows:

the invention belongs to the technical field of 3d printing, and particularly relates to a device for blowing off splashed metal particles and smoke dust in a printed layer of a printing machine 3, and a control method of blowing.

Background art:

the laser selective melting (SLM) technology utilizes focused laser beams to selectively melt metal powder layer by layer and build up the metal powder into a solid with metallurgical bonding and compact structure. Specifically, the scanning galvanometer is used for controlling the laser beam to selectively melt metal powder according to path information, and the powder in the area which is not irradiated by the laser still keeps the original loose state. After the layer is processed, the powder supply cylinder rises to a certain height, the forming cylinder falls to a layer thickness, and the scraper moves to flatly spread the powder lifted by the powder supply cylinder in the forming area for the next layer of processing.

In conventional gas circulation system, often can cause some regions of metal powder bed to cause non-splash metal powder to be blown away because the wind speed is too high because the mouth of blowing in the storehouse is far away from the laser scanning region or the wind speed is inhomogeneous in the shaping plane scope, or some regions are too low because the wind speed, can not blow away the splash metal granule that laser scanning powder bed in-process produced, fall on the powder bed in a large number, cause this laser scanning plane unevenness, also can influence shop's powder effect next time. It is therefore necessary to provide a new device and method for blowing off these splashed particles and smoke.

The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

The invention content is as follows:

the object of the present invention is to provide a device for blowing off the splashing metal particles and fumes, overcoming the drawbacks of the prior art mentioned above.

In order to achieve the purpose, the invention provides a device for blowing off splashed metal particles and smoke dust, which is arranged at the upper part of a metal printing bin, wherein the metal printing bin is a sealed bin body;

the bottom of the metal printing bin is sequentially hung with a powder supply cylinder, a forming cylinder and a powder collecting cylinder which are provided with openings according to the working sequence, and the scraper moves back and forth among the openings of the powder supply cylinder, the forming cylinder and the powder collecting cylinder and is used for sequentially conveying metal powder in the powder supply cylinder to the forming cylinder and the powder collecting cylinder;

laser is projected to the right upper part of the forming cylinder from the upper part of the metal printing bin to locally melt metal particles;

the device mainly comprises a gas circulation system and a cross-flow fan, wherein the gas circulation system is arranged on the side wall of the metal printing bin and comprises at least one blowing port and one air suction port, and is used for blowing metal particles floating in the metal printing bin out of the metal printing bin according to the arrangement direction of the powder supply cylinder, the forming cylinder and the powder collection cylinder; the cross-flow fan is arranged on the scraper, an air outlet of the cross-flow fan is parallel to the movement plane of the scraper, and the air outlet direction of the cross-flow fan is basically consistent with the air flow movement direction of the air circulation system. The wind blown from the air outlet can play a role in blowing off particles and smoke dust splashed by parts in the process of scanning the powder by laser.

Preferably, in the above technical scheme, the gas circulation system includes a blowing port of the gas circulation system disposed on one side of the powder supply cylinder and an air suction port of the gas circulation system disposed on one side of the powder collection cylinder, and when the blowing port of the gas circulation system blows out air flow at a certain flow rate and the air suction port of the gas circulation system generates negative pressure air suction at a certain pressure, a one-way clean air channel is formed in the metal printing bin.

Preferably, in the above technical solution, the height of the air blowing opening of the air circulation system is higher than the height of the air suction opening of the air circulation system on the basis of the bottom of the metal printing bin.

Preferably, in the above technical scheme, the bottom of the metal printing bin is used as a reference, and the height of the air outlet of the cross flow fan is substantially consistent with the height of the air suction inlet of the air circulation system.

Preferably, in the above technical solution, the length of the crossflow blower is not less than the length of the molding region.

Preferably, in the above technical solution, the gas blown out by the gas circulation system and the cross flow fan is an inert gas with a certain degree of cleanliness. Inert protective gas can be provided for the whole chamber, and the molten pool is prevented from being oxidized in the process of scanning the metal powder by laser.

Preferably, in the above technical solution, the air circulation system and the air output of the crossflow blower may be adjusted by respective control systems. The rotating speed of the fan is adjusted by the control power supply, the wind speed is adjusted according to the actual blowing effect of the splashed particles and the smoke dust, the splashed particles and the smoke dust on the whole forming surface can be completely blown away, and unscanned powder on the powder bed can not be blown away.

A control method for blowing off splashed metal particles and smoke dust mainly comprises the following steps: the preparation method comprises the following steps: a scraper scrapes a certain amount of metal powder from the powder supply cylinder and spreads the metal powder on the surface of the opening of the forming cylinder, the excessive amount of metal powder is pushed to the powder collecting groove, and the cross-flow fan is driven by the scraper to run between the forming cylinder and the powder supply cylinder;

starting the cleaning system: the gas circulation system and the cross flow fan are simultaneously started, and the gas circulation system and the cross flow fan blow floating metal particles and laser-burned smoke dust to the powder collecting groove and the air suction port of the gas circulation system; the powder collecting groove is arranged on the right side of the forming area, so that not only can redundant powder scraped by a scraper be collected, but also splash particles with larger particle size blown by a fan in the laser scanning process can be collected. During the laser scanning process, the entrained soot and less dense particles blown from the forming zone are absorbed.

Laser printing: the laser equipment reflects laser to metal particles on a preset area on the surface of the forming cylinder to complete the melting work of a layer of metal powder;

the cleaning system was shut down and the three steps described above were repeated.

Preferably, in the above technical scheme, in the preparation step, the support base of the powder supply cylinder is raised to a certain height to ensure that a certain number of metal particles are higher than the bottom surface of the metal printing bin, the support base of the forming cylinder is lowered to a certain height to ensure that the metal burning surface is lower than the opening of the forming cylinder, and the scraper pushes the metal particles higher than the opening of the powder supply cylinder to the forming cylinder and ensures that the metal powder layer is flush with the opening of the forming cylinder.

Compared with the prior art, the invention has the following beneficial effects:

the powder that splashes is clear away to the fixed point has been realized, the good technical defect who has solved the preceding top fan clean effect of blowing poor that has.

Description of the drawings:

FIG. 1 shows the operation of the apparatus for blowing off the splashed metal particles and the soot.

FIG. 2 is a structural view of a splash metal particle and soot blowing apparatus.

In figure 2, the numbers are 1-air circulation system blowing port, 2-scraper, 3-cross flow fan, 4-powder collecting groove, 5-air circulation system suction port, 6-forming cylinder, 7-powder supply cylinder, a-scraper left side limit, b-scraper middle waiting position and c-scraper right side limit respectively.

The specific implementation mode is as follows:

the following detailed description of specific embodiments of the invention is provided, but it should be understood that the scope of the invention is not limited to the specific embodiments.

Throughout the specification and claims, unless explicitly stated otherwise, the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element or component but not the exclusion of any other element or component.

Referring to fig. 2, the set of the splashing metal particle and smoke dust blowing device mainly comprises: the blowing port 1 of the gas circulation system, the scraper 2, the cross flow fan 3, the powder collecting groove 4 and the suction port 5 of the gas circulation system.

The scraper 2 starts from the left side a of the powder feeding cylinder 7, pushes the powder to move to the middle position b of the forming cylinder and the powder feeding cylinder for waiting.

And a fan of the gas circulation system and the cross flow fan 3 are started, laser light is emitted for scanning, and the cross flow fan 3 continuously blows off splashed particles and smoke dust.

And after the laser scanning is finished, stopping the fan of the gas circulation system and the cross-flow fan, descending the cylinder body of the forming cylinder 6 by one layer thickness, and pushing the powder to be tiled in a forming area by a scraper until the limiting position c of the powder collecting groove is reached.

The scraper returns to the position a limited on the left side of the powder supply cylinder, and the powder supply cylinder is lifted by a certain height to lift a certain amount of powder. The process is circulated.

According to the device and the method for blowing away the particles and the smoke dust in the laser scanning powder bed process, on the basis of blowing away the particles and the smoke dust at the air blowing port of the gas circulation system, a cross flow fan provides a short-distance and uniform and stable wind field on the horizontal plane, secondary enhanced blowing away is carried out on the particles and the smoke dust, the problems that wind power in some areas of a forming area is too large and wind power in some areas is too small are effectively solved, the effect of completely driving the particles and the smoke dust away from the forming area can be achieved, convenience, rapidness and effectiveness are achieved, and the practicability is high.

The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. It is not intended to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and its practical application to enable one skilled in the art to make and use various exemplary embodiments of the invention and various alternatives and modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims and their equivalents.