Accurate powder supply mechanism of SLS selective laser sintering 3D printer

Abstract

The utility model relates to an SLS selective laser sintering 3D printer precise powder supply mechanism which comprises a powder storage box, a powder stirrer and a precise powder falling hopper are arranged in the powder storage box, one end of a rotating shaft of the powder stirrer is driven by a motor, the precise powder falling hopper is located on the lower side of the powder stirrer and located at a powder outlet of the powder storage box, and the precise powder falling hopper is provided with a powder falling cavity with the wide upper portion and the narrow lower portion. Partitions formed in the powder falling cavity evenly divide the powder falling cavity into a plurality of powder falling channels, a powder control shaft in the length direction of the powder falling opening is arranged at the position, close to the powder falling opening, in the powder falling cavity, the shaft diameter and length of the powder control shaft are precisely matched with the width and length of the powder falling opening, and a plurality of V-shaped powder grooves in the axial direction are evenly formed in the surface of the powder control shaft. One end of the powder control shaft is driven by a motor. According to the precise powder supply mechanism of the SLS selective laser sintering 3D printer, single-time quantitative precise powder supply can be achieved, it is guaranteed that powder evenly flows out of the powder outlet, and therefore a foundation is laid for providing an excellent powder laying effect for a follow-up powder laying mechanism.

Description

Technical Field

[0001] This utility model relates to the field of 3D printer manufacturing technology, and in particular to a precision powder supply 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] Currently, SLS 3D printers on the market either use a lifting-type top-discharge method or a solenoid valve-controlled bottom-discharge method for their powder supply mechanism. Neither method can achieve precise single-discharge quantity, resulting in unstable powder output each time. Moreover, powder accumulates in the powder supply chamber, and due to the combined effects of powder flowability and viscosity, it is even more likely to cause uneven powder output each time and uneven powder output at different points in the powder outlet, thus comprehensively affecting the powder spreading effect of the powder spreading mechanism. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide a precision powder supply 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 precision powder supply mechanism for an SLS selective laser sintering 3D printer, including a powder storage box and a powder stirrer and a precision powder dispensing hopper disposed in the powder storage box. The powder stirrer consists of a rotating shaft and powder stirring blades fixed on the rotating shaft. The two ends of the rotating shaft are positioned by the powder storage box, and one end of the rotating shaft is driven by a motor. The precision powder dispensing hopper is located below the powder stirrer and at the powder outlet of the powder storage box. The precision powder dispensing hopper has a powder dispensing cavity that is wider at the top and narrower at the bottom, with a wider opening at the top. The powder inlet is at the bottom, and the narrow opening at the bottom is the powder outlet. A powder guide groove is provided at the powder outlet. A partition is formed in the powder outlet cavity, which evenly divides the powder outlet cavity into several powder outlet channels. A powder control shaft is provided in the powder outlet cavity close to the powder outlet along the length of the powder outlet. The diameter and length of the powder control shaft are precisely matched with the width and length of the powder outlet. Several V-shaped powder grooves are evenly formed on the surface of the powder control shaft along the axial direction. The two ends of the powder control shaft are positioned by a precision powder outlet hopper, and one end of the powder control shaft is driven by a motor.

[0007] Furthermore, each powder dispensing channel in the precision powder dispensing hopper is equipped with an elastic vibrating plate. The upper edge of each elastic vibrating plate is uniformly positioned by a vibrating plate positioning plate mounted on the precision powder dispensing hopper. Each elastic vibrating plate is located above the powder control shaft. When the powder control shaft rotates under the drive of the motor, the groove walls of each V-shaped powder groove of the powder control shaft will alternately and intermittently press against the lower edge of the elastic vibrating plate, causing the elastic vibrating plate to deform. During the rapid reset process, the elastic vibrating plate impacts and vibrates the powder control shaft.

[0008] Preferably, the aforementioned elastic vibration damper is made of spring steel.

[0009] To elaborate further, the rotating shaft and the powder control shaft of the powder mixer are driven by the same motor through a pulley assembly.

[0010] Preferably, the mixing blades of the powder mixer are spiral-shaped.

[0011] The beneficial effects of this utility model are: compared with the existing similar products on the market, the precision powder supply mechanism of this SLS selective laser sintering 3D printer can achieve precise single-quantity powder supply and ensure that the powder flows out evenly at the powder outlet, thus laying the foundation for the excellent powder spreading effect of the powder spreading mechanism. Attached Figure Description

[0012] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0013] Figure 1 This is a three-dimensional structural schematic diagram of the present invention;

[0014] Figure 2 , Figure 3 All of these are three-dimensional structural schematic diagrams of the precision powder dispensing hopper in this utility model (different perspectives; including the powder control shaft and elastic vibrating plate, etc.);

[0015] Figure 4 This is a three-dimensional structural diagram of the central control powder shaft and the elastic vibration plate of this utility model.

[0016] In the diagram: 1. Powder storage box; 2. Powder stirrer; 3. Precision powder drop hopper; 4. Powder control shaft; 4-1. V-shaped powder trough; 5. Elastic vibrating plate; 6. Vibrating plate positioning plate; 7. Powder drop trough. Detailed Implementation

[0017] A precision powder supply mechanism for an SLS selective laser sintering 3D printer, such as Figures 1 to 4 As shown, it includes a powder storage box 1, a powder mixer 2 and a precision powder dispensing hopper 3 disposed within the powder storage box 1. The powder mixer 2 consists of a rotating shaft and mixing blades fixed on the rotating shaft. Both ends of the rotating shaft are positioned by the powder storage box 1, and one end of the rotating shaft is driven by a motor. The precision powder dispensing hopper 3 is located below the powder mixer 2 and at the powder outlet of the powder storage box 1. The precision powder dispensing hopper 3 has a powder dispensing cavity that is wider at the top and narrower at the bottom. The wider top opening is the powder inlet, and the narrower bottom opening is the powder outlet. A powder guide is provided at the powder outlet. The powder dispensing chamber 7 has a partition 3-1 that divides the powder dispensing chamber into several powder dispensing channels. A powder control shaft 4 is set in the powder dispensing chamber close to the powder dispensing opening along the length of the powder dispensing opening. The shaft diameter and length of the powder control shaft 4 are precisely matched with the width and length of the powder dispensing opening. Several V-shaped powder grooves 4-1 are uniformly formed on the surface of the powder control shaft 4 along the axial direction. The two ends of the powder control shaft 4 are positioned by a precision powder dispensing hopper 3, and one end of the powder control shaft 4 is driven by a motor.

[0018] The stirring action of the powder stirrer 2 inside the powder storage box 1 ensures that the powder with a certain viscosity maintains good and stable flow within the powder storage box 1, ensuring that the powder can flow smoothly and evenly into each powder dropping channel of the precision powder dropping hopper 3 below. The powder flows out evenly through each powder dropping channel of the precision powder dropping hopper 3, laying the foundation for the uniform powder spreading operation of the subsequent powder spreading mechanism. The presence of the powder control shaft 4 in the precision powder dropping hopper 3 enables precise control of the amount of powder dispensed in a single operation: the powder loading capacity of a single V-shaped powder groove 4-1 of the powder control shaft 4 is pre-designed. Under the control of the motor, the angle of rotation of the powder control shaft 4 is constant each time, allowing a predetermined number (e.g., 3 grooves) of V-shaped powder grooves 4-1 to rotate to face downwards, so that the powder loaded in the grooves falls out. This ensures that the amount of powder falling from the precision powder dropping hopper 3 each time is constant, which is beneficial to the effect of the powder spreading operation of the subsequent powder spreading mechanism.

[0019] See Figures 2 to 4In this example, an elastic vibrating plate 5 is provided in each powder dispensing channel of the precision powder dispensing hopper 3. The upper edge of each elastic vibrating plate 5 is uniformly positioned by the vibrating plate positioning plate 6 mounted on the precision powder dispensing hopper 3. Each elastic vibrating plate 5 is located above the powder control shaft 4. When the powder control shaft 4 rotates under the drive of the motor, the groove wall of each V-shaped powder groove 4-1 of the powder control shaft 4 will alternately press the lower edge of the elastic vibrating plate 5, causing the elastic vibrating plate 5 to deform. During the rapid reset process, the elastic vibrating plate 5 will impact and vibrate the powder control shaft 4. The purpose of this solution is as follows: Because the powder has a certain degree of viscosity, in order to prevent a small amount of powder from adhering to the V-shaped powder trough 4-1 of the powder control shaft 4 when it falls as the powder control shaft 4 rotates, an elastic vibrating plate 5 is set next to the powder control shaft 4. When the powder control shaft 4 rotates, it touches the elastic vibrating plate 5, and the resulting vibration can cause the powder adhering to the trough to be shaken off completely, thereby ensuring the accuracy of the powder feeding.

[0020] In this example, the elastic vibrating pad 5 is made of spring steel to ensure its performance and service life.

[0021] In this example, to simplify the mechanical structure, the rotating shaft of the agitator 2 and the powder control shaft 4 are driven by the same motor through a pulley set.

[0022] In this example, the mixing blades of the powder mixer 2 are designed in a spiral shape, which provides a better mixing effect on the powder.

[0023] 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 precision powder feeding mechanism for SLS selective laser sintering 3D printer, comprising a powder storage box (1), characterized in that: It also includes a powder mixer (2) and a precision powder discharge hopper (3) installed in the powder storage box (1). The powder mixer (2) consists of a rotating shaft and powder mixing blades fixed on the rotating shaft. The two ends of the rotating shaft are positioned by the powder storage box (1), and one end of the rotating shaft is driven by a motor. The precision powder discharge hopper (3) is located below the powder mixer (2) and at the powder outlet of the powder storage box (1). The precision powder discharge hopper (3) has a powder discharge cavity that is wider at the top and narrower at the bottom. The wider top opening is the powder inlet, and the narrower bottom opening is the powder outlet. A powder guide trough (7) is provided at the powder outlet. A partition (3-1) is formed in the powder dispensing chamber, which divides the powder dispensing chamber into several powder dispensing channels. A powder control shaft (4) is set in the powder dispensing chamber close to the powder dispensing port along the length of the powder dispensing port. The shaft diameter and length of the powder control shaft (4) are precisely matched with the width and length of the powder dispensing port. Several V-shaped powder grooves (4-1) are uniformly formed on the surface of the powder control shaft (4) along the axial direction. The two ends of the powder control shaft (4) are positioned by a precision powder dispensing hopper (3). One end of the powder control shaft (4) is driven by a motor.

2. The precision powder feeding mechanism for SLS selective laser sintering 3D printer according to claim 1, characterized in that: An elastic vibrating plate (5) is provided in each powder dispensing channel of the precision powder dispensing hopper (3). The upper edge of each elastic vibrating plate (5) is uniformly positioned by the vibrating plate positioning plate (6) mounted on the precision powder dispensing hopper (3). Each elastic vibrating plate (5) is located above the powder control shaft (4). When the powder control shaft (4) rotates under the drive of the motor, the groove wall of each V-shaped powder groove (4-1) of the powder control shaft (4) will alternately press the lower edge of the elastic vibrating plate (5), causing the elastic vibrating plate (5) to deform. During the rapid reset process, the elastic vibrating plate (5) will impact and vibrate the powder control shaft (4).

3. The precision powder feeding mechanism for SLS selective laser sintering 3D printer according to claim 2, characterized in that: The elastic vibrating pad (5) is made of spring steel.

4. The precision powder feeding mechanism for SLS selective laser sintering 3D printer according to claim 1, characterized in that: The rotating shaft of the powder mixer (2) and the powder control shaft (4) are driven by the same motor through a pulley set.

5. The precision powder feeding mechanism for SLS selective laser sintering 3D printer according to claim 1, characterized in that: The agitator (2) has spiral blades.

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