Sls selective laser sintering 3d printer secondary powder spreading and scraping mechanism

Abstract

This utility model relates to a secondary powder spreading mechanism for an SLS selective laser sintering 3D printer, comprising a frame, a forming table, and a powder spreader. The powder spreader is horizontally and movably mounted above the forming table, and has a powder-carrying channel within it that matches the width of the forming table. A forward and reverse motor is controlled by a programmable controller. When the powder spreader moves linearly from above the powder support plate in its initial state to above the other end of the forming table, it returns along the same path until it reaches above the powder discharge port, and finally returns to directly above the powder support plate in its initial state. This secondary powder spreading mechanism for the SLS selective laser sintering 3D printer, after receiving powder from the powder supply mechanism, ensures that the powder spread on the forming table is uniform and flat each time through a powder spreading method that involves simultaneous powder dispensing and smoothing, as well as secondary compensation spreading operations. This improves the sintering effect of the laser beam on the powder and enhances the accuracy and quality of the final model.

Description

Technical Field

[0001] This utility model relates to the field of 3D printer manufacturing technology, and in particular to a secondary powder spreading mechanism for an SLS selective laser sintering 3D printer. Background Technology

[0002] SLS (Selective Laser Sintering) is an advanced 3D printing technology that uses an infrared laser as a heat source to sinter powder materials (mainly plastic powder, wax powder, metal powder, coated ceramic powder with a binder on the surface, coated metal powder, and coated sand, etc.) at high temperature, and build up layers to form three-dimensional parts.

[0003] The working principle and process of a current SLS 3D printer are roughly as follows: Powder particles are stored in the powder supply tank. During printing, the powder supply tank lifting platform rises, pushing the powder above the printing plane onto the printing platform (forming stage) through the powder spreading roller, forming a very thin powder layer. At this time, the laser beam scanning system selectively scans the powder layer according to the 2D CAD path of the slice. The scanned powder particles are sintered together due to the high temperature of the laser focus, thus generating a solid sheet with a certain thickness. The unscanned areas remain in their original loose powder state. After one layer is sintered, the printing platform descends by one layer thickness (usually 0.1mm) according to the slice height, and the powder spreading roller spreads the powder again before starting the sintering of a new layer. At this time, the layers are also sintered together simultaneously. This process is repeated until all layers are sintered. The unsintered powder is removed and recycled, and the printed solid model can be taken out.

[0004] Most SLS 3D printers on the market today spread powder on the forming table by pushing powder onto the forming table using rollers or scrapers. Each powder spreading operation only pushes once, making it difficult to ensure excellent uniformity and flatness of the powder spread surface. This greatly affects the scanning and sintering effect of the laser beam on the powder, resulting in a decrease in the accuracy and quality of the final model. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide a secondary powder spreading mechanism for an SLS selective laser sintering 3D printer, so as to overcome the defects and shortcomings of existing similar technologies and products as described in the background art.

[0006] The technical solution adopted by this utility model to solve its technical problem is: a secondary powder spreading mechanism for an SLS selective laser sintering 3D printer, including a frame, a forming table, and a powder spreader. The forming table is set in the frame, and the powder spreader is horizontally and movably mounted above the forming table via a set of linear slide rails at each end. A set of traction pulleys is also set at each end of the powder spreader. The sliders of the linear slide rails are fixedly connected to the belts of the traction pulleys on the same side. The drive wheels of the two sets of traction pulleys are simultaneously driven by a forward and reverse motor located in the frame. A powder-carrying groove adapted to the width of the forming table is formed in the powder spreader, and the lower edge of the groove is smooth and flat. One end of the forming platform is sequentially equipped with an initial state powder support plate for the powder spreader and a residual powder outlet for the powder spreader. The initial state powder support plate and the lower opening of the powder carrying channel of the powder spreader are attached to each other and can completely cover the lower opening of the powder carrying channel. The forward and reverse motors are controlled by a programmable controller. When the powder spreader moves linearly from above the initial state powder support plate to above the other end of the forming platform under the forward rotation of the forward and reverse motors, the programmable controller causes the forward and reverse motors to reverse, and the powder spreader returns along the original path until it reaches above the residual powder outlet of the powder spreader. Then the programmable controller causes the forward and reverse motors to rotate forward again, so that the powder spreader returns to directly above the initial state powder support plate of the powder spreader, ready to be loaded with powder into its powder carrying channel again.

[0007] Furthermore, the aforementioned forward and reverse motor is a dual-output shaft motor, with its two output shafts synchronously driving the drive wheel of the traction pulley assembly on one side.

[0008] The beneficial effects of this utility model are: compared with the existing similar products on the market, the secondary powder spreading mechanism of this SLS selective laser sintering 3D printer can ensure that the powder spread on the forming table is very uniform and flat in each step by the powder spreading method of simultaneous powder falling and smoothing and secondary compensation spreading operation after receiving the powder from the powder supply mechanism. This greatly helps to improve the scanning and sintering effect of the laser beam on the powder and improve the accuracy and quality of the final model. Attached Figure Description

[0009] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0010] Figure 1 , Figure 2 All are three-dimensional structural schematic diagrams of this utility model (different perspectives; when the powder spreader is located above the powder support plate in the initial state of the powder spreader (initial powder loading state of the powder spreader));

[0011] Figure 3 This is a three-dimensional structural diagram of the present invention (when the powder spreader moves back and forth above the forming table (powder spreader working state));

[0012] Figure 4This is a three-dimensional structural diagram of the present invention (when the powder spreader is located above the residual powder outlet of the powder spreader (the powder spreader is in the state of discharging residual powder)).

[0013] Figure 5 , Figure 6 , Figure 7 These are front view, top view, and three-dimensional structural schematic diagrams of the powder spreader in this utility model.

[0014] In the diagram: 1. Frame; 2. Forming table; 3. Powder spreader; 3-1. Powder carrying channel; 4. Linear slide rail; 5. Traction belt pulley set; 6. Forward and reverse motor; 7. Powder spreader initial state powder support plate; 8. Powder spreader residual powder drop outlet. Detailed Implementation

[0015] A secondary powder spreading mechanism for an SLS selective laser sintering 3D printer, such as Figures 1 to 6 As shown, it includes a frame 1, a forming table 2, and a powder spreader 3. The forming table 2 is located in the frame 1. The powder spreader 3 is horizontally movable above the forming table 2 via a set of linear slide rails 4 at each end. A set of traction pulleys 5 is also provided at each end of the powder spreader 3. The sliders of the linear slide rails 4 are fixedly connected to the belts of the traction pulleys 5 on the same side. The drive wheels of both sets of traction pulleys 5 are simultaneously driven by a forward and reverse motor 6 located in the frame 1. The powder spreader 3 has a powder-carrying groove 3-1 that matches the width of the forming table 2. The lower edge of the powder-carrying groove 3-1 is smooth and flat. A powder-holding device for the initial state of the powder spreader is sequentially provided at one end of the forming table 2. The plate 7 and the powder discharge port 8 of the powder spreader are in contact with each other. In the initial state, the powder support plate 7 and the lower side opening of the powder carrying channel 3-1 of the powder spreader 3 are attached and can completely cover the lower side opening of the powder carrying channel 3-1. The forward and reverse motor 6 is controlled by the programmable controller. When the powder spreader 3 moves linearly from above the powder support plate 7 in the initial state of the powder spreader to above the other end of the forming table 2, the programmable controller causes the forward and reverse motor 6 to reverse, and the powder spreader 3 returns along the original path until it reaches above the powder discharge port 8 of the powder spreader. Then the programmable controller causes the forward and reverse motor 6 to rotate forward again, so that the powder spreader 3 returns to the powder support plate 7 in the initial state of the powder spreader, so as to wait for powder to be loaded into its powder carrying channel 3-1 again.

[0016] In this example, to simplify the mechanical structure, the forward and reverse motor 6 is a dual-output shaft motor, with its two output shafts synchronously driving the drive pulley of the traction pulley group 5 on one side. The two ends of the powder spreader 3 are synchronously pulled and moved horizontally, which ensures that mechanical jamming or jamming will not occur due to force on one side.

[0017] When the powder spreader 3 is positioned directly above the powder support plate 7 in its initial state, it receives the powder supplied by the powder supply mechanism and stores it in its powder-carrying groove 3-1. Then, the powder spreader 3 begins to move horizontally above the forming table 2 to spread the powder. The powder gradually falls out of the powder-carrying groove 3-1 (but not all of it falls out at once, because the gap between the lower opening of the powder-carrying groove 3-1 and the powder-spreading surface is extremely small). The falling powder is then immediately covered by the smooth and flat lower opening of the powder-carrying groove 3-1. The powder spreader 3 is leveled by scraping and smoothing the surface (powder is applied and smoothed simultaneously). When the powder spreader 3 moves to the other end of the forming table 2, it returns along the same path (the height of the forming table 2 remains unchanged) and begins to make up for the first powder spreading process, filling and smoothing any depressions and unevenness that may have been left during the first powder spreading process, thereby ensuring excellent powder spreading effect. After the second powder spreading is completed, the small amount of powder remaining in the powder carrying channel 3-1 of the powder spreader 3 is discharged through the powder residual discharge port 8 of the powder spreader and received by the residual powder recycling mechanism.

[0018] The above embodiments are only used to explain the present utility model and are not intended to limit the protection of the present utility model. Any non-substantial modifications made based on the essential solution of the present utility model shall fall within the protection scope of the present utility model.

Claims

1. A secondary powder spreading mechanism for an SLS selective laser sintering 3D printer, comprising a frame (1), a forming table (2), and a powder spreader (3), wherein the forming table (2) is disposed in the frame (1), and the powder spreader (3) is horizontally and movably mounted above the forming table (2) via a set of linear slide rails (4) at each end thereof, characterized in that: At both ends of the powder spreader (3), there is a set of traction pulley groups (5). The slider of the linear slide rail (4) is fixedly connected to the belt of the traction pulley group (5) on the same side. The driving wheels of the two sets of traction pulley groups (5) are driven simultaneously by the forward and reverse motor (6) set in the frame (1). A powder carrying groove (3-1) adapted to the width of the forming table (2) is formed in the powder spreader (3). The lower groove edge of the powder carrying groove (3-1) is smooth and flat. At one end of the forming table (2), the powder spreading initial state powder support plate (7) and the powder spreading residual powder drop outlet (8) are set in sequence. The powder spreading initial state powder support plate (7) and the lower groove edge of the powder carrying groove (3-1) of the powder spreader (3) are attached and merged to completely cover the lower groove edge of the powder carrying groove (3-1).

2. The SLS selective laser sintering 3D printer secondary powder spreading and scraping mechanism according to claim 1, characterized in that: The reversible motor (6) is a dual-output shaft motor, and its two output shafts synchronously drive the drive wheel of the traction pulley group (5) on one side.

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