Lateral lifting temperature-controllable and powder-leakage-proof forming cylinder device of SLS3D printer

Abstract

The invention discloses a lateral lifting temperature-controllable and powder-leakage-proof forming cylinder device of an SLS3D printer, and belongs to the field of selective laser sintering equipment. Comprising a forming cylinder, the outer side wall of the forming cylinder is fixedly connected with a side face lead screw guide rail structure through a connecting piece, and a connecting pin is arranged on the outer side wall of the forming cylinder; through the lead screw module and the connecting pin, the forming cylinder can complete jacking of the printing platform from the side face, and the overall height of equipment is reduced. The periphery of the outer wall of the forming cylinder is wrapped with a polyimide (PI) heating film, and a heating plate and a temperature sensor are designed at the bottom of a printing platform, so that in the part printing process, even if the printing platform continuously descends and is continuously far away from an infrared heating area on the upper layer, the temperature in the cylinder body can still be controlled within + / -3 DEG C of the set temperature; compared with heating films made of other materials, the polyimide heating film used in the scheme is thin in thickness and more uniform in temperature field.

Description

Technical Field

[0001] The present invention relates to selective laser sintering equipment, and particularly to a side-lifting temperature-controllable and powder-leakage-preventing forming cylinder device for an SLS 3D printer. Background Art

[0002] The SLS equipment, namely the Selective Laser Sintering equipment, is an advanced 3D printing technology equipment. The SLS technology adopts a powder spreading method, spreads a layer of powder material on the surface of the already formed part, and heats it to a certain temperature just below the sintering point of the powder. The control system controls the laser beam to scan on the powder layer according to the cross-sectional contour of this layer, so that the temperature of the powder rises to the melting point, conducts sintering and realizes bonding with the already formed part below. After one layer is completed, the printing platform descends by the thickness of one layer, the feeding roller spreads a layer of uniform and dense powder on it, and conducts sintering of the new layer cross-section until the entire model is completed. Therefore, the forming chamber is an essential main component of such equipment.

[0003] However, there are many problems in the actual application of the forming cylinders attached to the current SLS equipment on the market. In terms of structural design, most equipment adopts the method of jacking up the printing platform from the bottom. This traditional structure greatly increases the height of the equipment. Taking a common industrial-grade SLS equipment as an example, the total height of the forming cylinder plus the jacking component is at least twice the printing depth, resulting in the equipment occupying a large amount of space, which not only puts forward higher requirements for the floor height and site area of the production workshop, but also increases the difficulty and cost of equipment transportation and installation. In addition, the excessive height of the equipment also brings inconvenience to the daily maintenance and debugging of the operators. Especially when it comes to the maintenance of the components at the top of the equipment, auxiliary tools such as ladders are often needed, which poses certain safety hazards;

[0004] In terms of temperature control, most of the forming cylinders on the market are not temperature - controllable. They are only processed and assembled into the shape of a cylinder using metal or non - metal parts, and at most, a layer of thermal insulation cotton is covered outside the cylinder. However, the heat - insulation performance of the thermal insulation cotton is limited, and it is difficult to resist the influence of external environmental temperature fluctuations on the inside of the forming cylinder. During the printing process, as the printing platform continuously descends away from the top heat source, an obvious gradient change will occur in the temperature field inside the cylinder. Especially when printing large parts, the temperature in the bottom area may deviate significantly from the set temperature. And SLS printing is extremely sensitive to temperature. Unstable temperature will lead to problems such as incomplete powder sintering, voids inside the parts, or warping and deformation, seriously affecting the printing quality and the mechanical properties of the parts. It should also be noted that the printing platform inside the forming cylinder needs to continuously descend with the printing process, so there will inevitably be a gap between the printing platform and the cylinder wall. Most existing devices use sealing rings or wool felt for sealing to prevent powder from leaking out through the gaps. However, the sealing ring is prone to aging and deformation in a high - temperature environment, losing its sealing effect; although the wool felt has a certain high - temperature resistance, it has a problem of poor wear resistance. During the frequent lifting and lowering of the printing platform, the friction with the cylinder wall will cause it to wear quickly, and once the wear is excessive, powder leakage will occur. Powder leakage will not only cause waste of printing materials, but also may contaminate other precision components inside the device, such as the laser optical path system, transmission mechanism, etc., thereby affecting the normal operation of the device and increasing the maintenance frequency and repair cost of the device. Summary of the Invention

[0005] Object of the Invention: The object of the present invention is to provide a forming cylinder device for SLS 3D printer with side - lifting of the printing platform, which reduces the overall height of the device and reduces the deformation of the printed parts caused by the change of temperature field. Another object of the present invention is to reduce the powder leakage in the forming cylinder during the printing process, improve the convenience of customers during the use of the printer, and reduce the replacement difficulty of the sealing components.

[0006] Technical Solution: A side - lifting temperature - controllable and powder - leakage - proof forming cylinder device for SLS 3D printer, including a forming cylinder. The outer side wall of the forming cylinder is fixedly connected with a side - mounted lead screw guide rail structure through a connecting piece. A connecting pin is arranged on the outer side wall of the forming cylinder, and the connecting pin is fixedly connected with the side - mounted lead screw guide rail structure.

[0007] Furthermore, a printing platform is fixedly connected inside the forming cylinder. A bottom polyimide heating film is fixedly connected to the lower surface of the printing platform. A bottom heat - insulating aerogel is fixedly connected to the lower surface of the bottom polyimide heating film. A surrounding polyimide heating film is arranged on the outer side wall of the forming cylinder.

[0008] Furthermore, a circle of wool felt is fixedly connected to the upper surface of the forming cylinder. Inside the wool felt on the upper surface of the forming cylinder, a floating push plate is fixedly connected. A plurality of age-hardened nickel-based alloy springs are fixedly connected between the floating push plate and the upper surface of the forming cylinder.

[0009] Furthermore, top infrared heating tubes are fixedly connected to the upper surface of the forming cylinder.

[0010] Furthermore, movable handles are fixedly connected to the outer side walls of the forming cylinder.

[0011] Furthermore, support grips are symmetrically and fixedly connected to the outer side walls of the forming cylinder.

[0012] Beneficial effects: Through the lead screw module and the connecting pin, the present invention innovatively enables the forming cylinder to lift the printing platform from the side. This design effectively reduces the overall height of the device, making it more advantageous in terms of space utilization, especially suitable for usage scenarios with limited installation space. And by wrapping the outer wall of the forming cylinder with a polyimide (PI) heating film, and designing a heating plate and a temperature sensor at the bottom of the printing platform, a precise temperature control system is formed. During the printing process of the part, even if the printing platform continuously descends and moves away from the upper infrared heating area, the temperature inside the cylinder body can still be controlled within ±3°C of the set temperature. The polyimide heating film used in this solution is thinner than heating films of other materials, and the temperature field is more uniform. Covering it on the outer wall of the aluminum forming cylinder, the temperature difference of the temperature transferred from the metal to the material is extremely small, and it can accurately and stably control the temperature change around the printed part, so that the part will not cool down and deform due to the continuous movement of the printing platform away from the upper infrared heating area. For the powder leakage situation of the forming cylinder, the present invention adds four groups of floating push plates around the printing platform, that is, uses age-hardened nickel-based alloy (NCF750) springs around, and places wool felt at the ends. This structure can well ensure the sealing of the forming cylinder. Even if part of the thickness of the wool felt is consumed by friction with the wall of the printing cylinder during use, the spring can still push the wool felt out at the tail with its excellent elasticity to ensure that the seal does not fail; in addition, this sealing structure is reasonably designed. While ensuring the sealing effect, it reduces the frequent replacement requirements due to wear of the sealing components. The printing platform is lifted from the side, reducing the overall height of the device, reducing the deformation of the printed part during the printing process due to the change of the temperature field around it, improving the accuracy of the printed part, increasing the sealing performance of the printing cylinder body, and greatly reducing the frequency of replacing the sealing consumables, reducing the workload of the customer, reducing the difficulty of the customer in replacing the sealing consumables, and improving their satisfaction in use. Description of the Drawings

[0013] Figure 1 is the overall structural schematic diagram of the present invention;

[0014] Figure 2 is a front view structural schematic diagram of the present invention;

[0015] Figure 3 is a sectional view structural schematic diagram of the present invention;

[0016] Figure 4 is the present invention Figure 2 magnified structural schematic diagram at position A;

[0017] Figure 5 is a top view structural schematic diagram of the forming cylinder of the present invention;

[0018] Figure 6 is a side view structural schematic diagram of the top infrared heating tube of the present invention;

[0019] Figure 7 is an overall structural schematic diagram of the top infrared heating tube of the present invention;

[0020] Figure 8 is the present invention Figure 7 magnified structural schematic diagram at position B;

[0021] In the figure: 1, forming cylinder; 2, connecting pin; 3, side screw rod guide rail structure; 4, top infrared heating tube; 1-1, printing platform; 1-2, bottom polyimide (PI) heating film; 1-3, bottom heat insulation aerogel; 1-4, peripheral polyimide (PI) heating film; 1-6, wool felt; 1-7, floating push plate; 1-8, strengthened nickel-based alloy (NCF750) spring. Detailed implementation manners

[0022] To make the technical solution of the present invention clearer, the following further describes the present invention in detail with reference to the accompanying drawings and specific embodiments.

[0023] Embodiment

[0024] As Figures 1-8As shown, a side lifting temperature-controllable and powder leakage-proof forming cylinder device of an SLS 3D printer is provided, comprising a forming cylinder 1, the outer wall of the forming cylinder 1 is fixedly connected to a side screw guide structure 3 through a connecting piece, the outer wall of the forming cylinder 1 is provided with a connecting pin 2, the connecting pin 2 is fixedly connected to the side screw guide structure 3, the interior of the forming cylinder 1 is fixedly connected to a printing platform 1-1, the lower surface of the printing platform 1-1 is fixedly connected to a bottom polyimide (PI) heating film 1-2, the bottom polyimide (PI) heating film 1-2 The lower surface of the molding cylinder 1 is fixedly connected with a bottom heat-insulating aerogel 1-3, the outer wall of the molding cylinder 1 is provided with a surrounding polyimide (PI) heating film 1-4, the upper surface of the molding cylinder 1 is fixedly connected with a circle of wool felt 1-6, the upper surface of the molding cylinder 1 is fixedly connected with a floating push plate 1-7 located inside the wool felt 1-6, a plurality of aging-strengthening nickel-based alloy NCF750 springs 1-8 are fixedly connected between the floating push plate 1-7 and the upper surface of the molding cylinder 1, and the upper surface of the molding cylinder 1 is fixedly connected with a top infrared heating tube 4;

[0025] At the beginning of the SLS equipment printing process, the system will initialize and calibrate the side screw guide structure 3 to ensure that the printing platform 1-1 is at a precise starting height, laying the foundation for subsequent layer-by-layer printing. As the printing command is issued, the printing platform 1-1 is driven by the side screw guide structure 3 to drive the connecting pin 2 to achieve stable lifting and lowering movement with micron-level accuracy. After each layer of printing is completed, the printing platform 1-1 will move downward according to the preset layer thickness, gradually moving away from the top infrared heating tube 4. This process will cause the temperature field inside the forming cylinder 1 to change, and the temperature will gradually drop. The printing material is extremely sensitive to temperature. A slight deviation may lead to incomplete sintering or over-sintering, affecting the molding quality.

[0026] At this time, the high-precision temperature sensor built in the polyimide (PI) heating film 1-2 wrapped around the heating film 1-4 starts to function. It monitors the temperature change in the forming cylinder 1 in real time with a response speed in milliseconds and feeds the data back to the equipment control system. The control system uses an intelligent algorithm to determine whether to start the heating program based on the preset temperature curve and the characteristics of the printing material. When the detected temperature is lower than the set threshold, the polyimide (PI) heating film 1-2 selectively conducts zone heating, which can not only quickly replenish heat but also precisely control according to the temperature difference in different regions to maintain a stable temperature environment in the forming cylinder. At the same time, the thermal insulation aerogel 1-3 at the bottom of the forming cylinder 1 continuously functions, and its nano-porous structure effectively isolates the heat from dissipating downward, further enhancing the stability of the temperature field in the printing cylinder and ensuring that the printing material is sintered and formed under appropriate temperature conditions. During the lifting process of the printing platform 1-1, the side screw guide rail structure 3 ensures its smooth and precise movement through a closed-loop feedback system, avoiding the misalignment of the printing layer caused by shaking. The age-hardened nickel-based alloy (NCF750) spring 1-8 always maintains a pressure-retaining state. With its excellent anti-fatigue performance and stable elastic coefficient, it continuously pushes out the floating push plate 1-7, making the wool felt 1-6 closely fit the inner wall of the forming cylinder body 1. This structural design effectively prevents the printing powder from leaking in the forming cylinder body 1, not only ensuring the cleanliness of the printing process, avoiding powder contamination of the working environment, preventing waste of printing materials caused by powder leakage, but also ensuring the uniformity and stability of the powder bed in the forming cylinder. In addition, the wool felt 1-6 also has good buffering performance, which can absorb the micro-vibrations generated during the printing process, further improving the printing accuracy and providing a reliable guarantee for high-quality printing and forming.

[0027] In this embodiment, movable handles 1-9 are fixedly connected to the outer side walls of the forming cylinder 1, and support grips 1-10 are symmetrically and fixedly connected to the outer side walls of the forming cylinder 1;

[0028] The movable handle 1-9 equipped on the forming cylinder 1 and the supporting grip 1-10 cooperate with each other to jointly serve the operation and use of the forming cylinder. In actual work, the movable handle 1-9 can rotate or adjust its position flexibly. When it is necessary to move the forming cylinder 1, the operator can quickly hold the movable handle 1-9, utilize its flexible characteristics, conveniently adjust the holding angle, apply force in a more labor-saving posture, push or pull the forming cylinder 1, and move it to the required position within the working site; while the supporting grips 1-10 are symmetrically distributed on the outer side wall of the forming cylinder 1. During the working process of the forming cylinder 1, especially when performing some tasks that require fine operation or high stability requirements, the operator can hold the supporting grips 1-10 on both sides at the same time to provide a stable supporting force for the forming cylinder 1, avoid the forming cylinder 1 from shaking due to external interference or vibration during the operation process, and ensure the accuracy of the forming work; in scenarios such as equipment debugging and maintenance, the staff can also hold the movable handle 1-9 with one hand for fine position adjustment, and tightly hold the supporting grip 1-10 with the other hand to keep the forming cylinder stable, ensuring that all operations are completed safely and efficiently.

[0029] The above-described embodiments merely represent several implementation manners of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A lateral lifting, temperature-controllable, and powder-leakage-proof molding cylinder device for an SLS 3D printer, comprising a molding cylinder (1), characterized in that: The outer wall of the molding cylinder (1) is fixedly connected to a side screw guide rail structure (3) via a connecting piece, and a connecting pin (2) is provided on the outer wall of the molding cylinder (1), and the connecting pin (2) is fixedly connected to the side screw guide rail structure (3).

2. The SLS 3D printer side lifting temperature controllable and powder leakage prevention molding cylinder device according to claim 1 is characterized in that: The interior of the molding cylinder (1) is fixedly connected to a printing platform (1-1), the lower surface of the printing platform (1-1) is fixedly connected to a bottom polyimide (PI) heating film (1-2), the lower surface of the bottom polyimide (PI) heating film (1-2) is fixedly connected to a bottom heat-insulating aerogel (1-3), and the outer wall of the molding cylinder (1) is provided with a surrounding polyimide (PI) heating film (1-4).

3. The SLS 3D printer side lifting temperature controllable and powder leakage prevention molding cylinder device according to claim 1 is characterized in that: A circle of wool felt (1-6) is fixedly connected to the upper surface of the molding cylinder (1); a floating push plate (1-7) is fixedly connected to the upper surface of the molding cylinder (1) and located inside the wool felt (1-6); and a plurality of age-hardened nickel-based alloy (NCF750) springs (1-8) are fixedly connected between the floating push plate (1-7) and the upper surface of the molding cylinder (1).

4. The SLS 3D printer side lifting temperature controllable and powder leakage prevention molding cylinder device according to claim 1 is characterized in that: A top infrared heating tube (4) is fixedly connected to the upper surface of the forming cylinder (1).

5. The SLS 3D printer side lifting temperature controllable and powder leakage prevention molding cylinder device according to claim 1 is characterized in that: The outer side walls of the forming cylinder (1) are fixedly connected with movable handles (1-9).

6. The SLS 3D printer side lifting temperature controllable and powder leakage prevention molding cylinder device according to claim 1, characterized in that: The outer side wall of the forming cylinder (1) is symmetrically and fixedly connected with a support handle (1-10).

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