Selective laser melting powder spreading device

Abstract

The invention discloses a selective laser melting powder spreading device and a using method thereof, and is mainly characterized in that the selective laser melting powder spreading device comprises a powder scraping mechanism, a pressing mechanism, a transmission device, a track and a powder storage bin, a scraping plate in the powder scraping mechanism is composed of rakes which are arranged in a staggered mode, and the pressing mechanism is composed of a hydraulic oil spring and a roller; the powder scraping mechanism and the pressing mechanism are in transmission control through the transmission mechanism, accurate transmission control over the running distance of the powder laying device is carried out through a lead screw, a servo motor and a coupler in front of the powder laying device, and accurate direction control over the powder laying device is carried out through a guide rail in back of the powder laying device. The powder storage bin is mainly used for storing powder. The laser selective melting device has the beneficial effects that powder can be efficiently and stably preset into the workbench and is pressed through the pressing mechanism, tightly stacked powder particles are obtained, and the powder blowing phenomenon in the laser selective melting process is reduced.

Description

Technical Field

[0001] The invention patent relates to the field of additive manufacturing, and specifically to a powder spreading mechanism for laser additive manufacturing. Background Art

[0002] Additive manufacturing technology is a new manufacturing technology that has developed rapidly in recent years. It produces three-dimensional samples in a "layered manufacturing, layer-by-layer accumulation" manner. The samples prepared by additive manufacturing technology have the characteristics of high molding precision, diversified design space, and high production efficiency. The sample size ranges from nanometers to meters. It has shown immeasurable development prospects in a series of strategic fields such as new energy, new materials, high-end medical equipment, aerospace, and rail transportation.

[0003] Among them, the common methods of metal material additive manufacturing technology include laser selective melting technology, laser metal sintering technology, laser fuse deposition technology and arc additive manufacturing technology.

[0004] Laser additive manufacturing technology has the characteristics of high energy density, high energy utilization, high molding precision, and good molding quality. At the same time, in a vacuum environment, it has unique advantages in processing certain special components and metal materials with high gas sensitivity.

[0005] Although the laser selective melting additive manufacturing technology has the above advantages, the current laser selective melting additive manufacturing equipment still has many shortcomings, such as the inability to perform real-time temperature monitoring, poor powder spreading quality, insufficient control of powder feeding by the powder storage bin, and no water cooling system. As a result, powder is wasted and the powder spreading effect is poor during the laser selective melting additive manufacturing process, which can easily cause powder blowing and poor molding quality. Summary of the invention

[0006] The technical problem to be solved by the patent of this invention is to provide an economical, accurate, high-quality laser selective melting powder spreading mechanism to obtain high-quality metal powder for processing, thereby reducing the generation of blowing powder, improving the accuracy of the entire processing process, and facilitating the large-scale production of laser selective melting additive manufacturing equipment.

[0007] To achieve the above object, the present invention adopts the following technical solutions: A laser selective melting powder spreading device, characterized in that it includes a powder scraping mechanism, a pressing mechanism, a transmission device, a track, and a powder storage bin; the powder scraping mechanism is composed of two stainless steel plates and four screws connecting left and right scrapers, and the single-side scraper is composed of rakes arranged in an interlaced manner, and a certain interval is left between the scrapers on both sides for storing the metal powder melted in the selected area; a triangular guide rail is fixed by screws directly behind the powder scraping mechanism, and a left limit block and a right limit block are respectively set on the left and right sides of the triangular guide rail, and the left and right limit blocks respectively control the left and right running end points of the powder scraping mechanism; the transmission device includes a horizontal transverse triangular guide rail, a screw, a coupling, and a servo motor; the triangular guide rail is horizontally placed directly behind the powder scraping mechanism; the screw is horizontally placed directly in front of the powder scraping mechanism, with both ends placed on two vertical baffles, the left side is connected to the servo motor, and the coupling is installed on the screw to drive the powder scraping mechanism to move.

[0008] Preferably, a single scraper mechanism of the powder scraping mechanism is composed of 13 interlaced rake structures, a single rake has 26 teeth, a tooth width of 2 mm, a gap between teeth of 2 mm, and a thickness of a single sheet of 0.3 mm.

[0009] Preferably, two assembled scrapers are fixed by bolts on both sides of the powder scraping mechanism.

[0010] Preferably, two fixed structures are welded on the powder scraping mechanism, and the hydraulic spring is fixed at the other end of the fixed structure with bolts. The hydraulic spring is connected to a roller cover, and a roller is located under the roller cover for pressing metal powder.

[0011] Preferably, the hydraulic spring stroke is 5 mm, and the roller is an unpowered stainless steel roller with a size of φ15 mm×110 mm.

[0012] Preferably, a triangular guide rail is fixed by screws directly behind the powder scraping mechanism, and a left limit block and a right limit block are respectively provided on the left and right sides of the triangular guide rail.

[0013] Preferably, the powder spreading mechanism is connected to a coupling, and the horizontally placed lead screw is directly in front of it. The leftmost end of the lead screw is the servo motor, and the servo motor uses the lead screw and the coupling to control the left and right movement of the powder scraping mechanism and the pressing mechanism.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] 1. The present invention adopts a combination of interlaced rake structures and uses a lead screw, a servo motor and a triangular guide rail to fill the metal powder, which can maximize the amount of metal powder stored in the powder storage bin as much as possible without forcing it to be completely transported to the workbench.

[0016] 2. The patent of the present invention adopts a hydraulic spring to connect a stainless steel roller, welds it to a powder scraping mechanism, and uses a lead screw, a servo motor and a triangular guide rail to press the metal powder. It can press the uneven powder during the scraping process to make it flat, and significantly improve the density of the powder, effectively preventing the occurrence of powder blowing.

[0017] 3. The patent of the present invention adopts a lead screw, a servo motor, a coupling and a triangular guide rail to control the left and right sliding of the scraping mechanism and the pressing mechanism in the horizontal position, and uses left and right limit blocks on the triangular guide rail to limit the left and right positions, so that the whole process can be precisely controlled. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a three-dimensional schematic diagram of a laser selective melting powder spreading device of the present invention;

[0019] Figure 2 This is a front view of a laser selective melting powder spreading device of the present invention;

[0020] Figure 3 It is a three-dimensional schematic diagram of a powder scraping mechanism and a pressing mechanism in a laser selective melting powder spreading device of the present invention;

[0021] Figure 4 It is a three-dimensional schematic diagram of a powder scraping mechanism in a laser selective melting powder spreading device of the present invention;.

[0022] Figure 5 It is a three-dimensional schematic diagram of a thin slice rake in a scraper of a powder scraping mechanism in a laser selective melting powder spreading device of the present invention;

[0023] Figure 6 It is a cross-sectional view of a powder scraping mechanism in a laser selective melting powder spreading device of the present invention;

[0024] Numbers in the figure: 1. servo motor; 2. hydraulic spring; 3. guide rail; 4. limit block; 5. drum cover; 6. powder scraping mechanism; 7. powder storage bin; 8. lead screw; 9. coupling; 10. drum; 11. workbench; 12. fixing device; 61. screw; 62. rake combination structure; 63. stainless steel plate; 621. single rake; 622. pad. Implementation

[0025] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly describe the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0026] See also Figure 1-6The present invention provides a technical solution: a laser selective melting powder spreading device, including a servo motor 1, a hydraulic spring 2, a guide rail 3, a limit block 4, a roller cover 5, a powder scraping mechanism 6, a powder storage bin 7, a lead screw 8, a coupling 9, a roller 10, a workbench 11, a fixing device 12, a screw 61, a rake combination structure 62, a stainless steel plate 63, a single rake 621, a pad 622, 13 single rakes 621 and 12 pads are combined into 2 scrapers, which are fixed by bolts and are respectively located at the left and right ends of the powder scraping mechanism 6, leaving a certain interval in the middle, 30 mm apart, and two parallel fixings are welded at the left end of the powder scraping mechanism 6, and the other end is connected with bolts. Hydraulic spring 2, the other end of the hydraulic spring 2 is connected to the roller cover 5, and the roller 10 is connected below the roller cover 5; three steel plates are fixed to the left, right and front directions of the entire mechanism respectively, fixed with screws and perpendicular to each other at 90°, the servo motor 1 is fixed to the left front side of the left steel plate, and horizontally connected to the lead screw 8, the other end of the lead screw 8 is placed on the right steel plate, and a coupling 9 is placed, and the coupling 9 is connected to the powder scraping mechanism 6 by screws; the guide rail 3 is fixed on the rear steel plate, the right end of the guide rail 3 is tightly attached to the right steel plate, and the left and right sides are respectively fixed with limited blocks 4 with screws, the workbench 11 is located directly below the powder scraping mechanism 6, and its left and right ends are respectively powder storage bins 7, and the middle part is the working area.

[0027] In summary, when the laser selective melting powder spreading device is in use, since positions of powder storage bins 7 are reserved on the left and right sides of the workbench 11 for storing metal powder, after the metal powder is stacked to a certain amount, since the servo motor 1 is connected to a lead screw, the lead screw is connected to a coupling 9, and the coupling 9 is connected to a powder scraping mechanism 6 and a pressing mechanism 5, the servo motor 1 rotates to drive the coupling 9, thereby driving the powder scraping mechanism 6 to move to the left, and the powder scraping mechanism 6 scrapes the powder to the powder spreading area of ​​the workbench 11, and scrapes the remaining powder into the powder storage bin 7 on the left side of the workbench 11. During this period, precise direction control is performed through the guide rail 3 to ensure precise positioning. The left and right limit blocks 4 are respectively fixed with screws at the left and right ends of the guide rail 3. After completing the powder scraping work, the servo motor 1 rotates again to drive The coupling 9 drives the powder scraping mechanism 6 to move to the right. Since the powder scraping mechanism 6 has scraped the remaining metal powder into the powder storage bin 7 on the left side of the workbench 11, the powder scraping mechanism does not work at this time. Due to the action of the hydraulic spring 2, the pressing mechanism exerts downward pressure on the roller 10 when being driven to move to the right. The roller 10 presses the metal powder tightly, thereby achieving a dense powder layer that can be processed. During this period, precise direction control is performed through the guide rail 3 to ensure accurate positioning. The left and right ends of the guide rail 3 are respectively fixed with screws to the left and right limit blocks 4 to complete a powder spreading work. The servo motor 1 is controlled by PLC to facilitate the improvement of the powder spreading method. This cycle can accurately and efficiently complete each powder spreading and obtain a high-quality dense powder layer.

[0028] The above are only preferred specific implementation modes of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A laser selective melting powder spreading device. It is characterized by: It includes a powder scraping mechanism, a pressing mechanism, a transmission device, a track, and a powder storage bin; the powder scraping mechanism is composed of two stainless steel plates and four screws connecting the left and right scrapers, the single-side scraper is composed of rakes arranged in an interlaced manner, and a certain interval is left between the scrapers on both sides for storing the melted metal powder in the selected area; a triangular guide rail is fixed by screws directly behind the powder scraping mechanism, and a left limit block and a right limit block are respectively set on the left and right sides of the triangular guide rail, and the left and right limit blocks respectively control the left and right running end points of the powder scraping mechanism; the transmission device includes a horizontal transverse triangular guide rail, a lead screw, a coupling, and a servo motor; the triangular guide rail is horizontally placed directly behind the powder scraping mechanism; the lead screw is horizontally placed directly in front of the powder scraping mechanism, with both ends placed on two vertical baffles, the left side is connected to the servo motor, and the lead screw is equipped with the coupling to drive the powder scraping mechanism to move.

2. The laser selective melting powder spreading device according to claim 1, characterized in that: A single scraper in the powder scraping mechanism is composed of 13 interlaced rake structures, a single rake has 26 teeth, a tooth width of 2 mm, a gap between teeth of 2 mm, and a thickness of a single sheet of 0.3 mm.

3. A laser selective melting powder spreading device according to claims 1 and 2, characterized in that: Two assembled scrapers are fixed by bolts on both sides of the powder scraping mechanism.

4. A laser selective melting powder spreading device according to claim 1, 2 or 3, characterized in that: Two fixed structures are welded on the powder spreading device, and the hydraulic spring is fixed at the other end of the fixed structure with bolts. The hydraulic spring is connected to a roller cover, and a roller is located under the roller cover for pressing metal powder.

5. The laser selective melting powder spreading device according to claim 3, characterized in that: The hydraulic spring stroke is 5 mm; the roller is a non-powered stainless steel roller with a size of φ15 mm×110 mm.

6. The laser selective melting powder spreading device according to claim 1, characterized in that: A triangular guide rail is fixed by screws directly behind the powder scraping mechanism, and a left limit block and a right limit block are respectively arranged on the left and right sides of the triangular guide rail.

7. The laser selective melting powder spreading device according to claim 1, characterized in that: The powder spreading mechanism is connected to a coupling, and the horizontally placed lead screw is directly in front of it. The leftmost end of the lead screw is the servo motor, and the servo motor uses the lead screw and the coupling to control the left and right movement of the powder scraping mechanism and the pressing mechanism.

8. Method for using the laser selective melting powder spreading device: Pour the metal powder material into the powder storage bin in a quantitative manner. After completing one process, the servo motor starts to drive the powder spreading mechanism and the pressing mechanism to move to the left through the coupling until the metal powder completely covers the workbench. The servo motor starts again to drive the powder spreading mechanism and the pressing mechanism to move to the right through the coupling to complete a work process. The pressing mechanism presses the newly spread metal powder when returning to obtain dense metal powder.

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