Continuous variable 3D printing device

Abstract

The continuous variable 3D printing device comprises a heating stirring barrel; an extrusion screw rod is rotationally connected into the heating and stirring barrel; the outer end of the extrusion screw rod is connected with a motor; the side edge of the heating and stirring barrel is connected with a feeding pipeline, and the lower end of the heating and stirring barrel is connected with a spray head fixing block; a spray head is mounted below the spray head fixing block; the spray head comprises two spray head sliding rail blocks and two spray head sliding blocks; the two nozzle sliding blocks are transversely connected between the two nozzle sliding rail blocks in a sliding mode. Mounting panels are connected to the left sides and the right sides of the two spray head sliding rail blocks; the two mounting panels are connected with a first linear motor and a second linear motor respectively. The distance between the two spray head sliding blocks can be continuously adjusted through the first linear motor and the second linear motor, so that the caliber of the spray head can be continuously changed to adapt to various application scenes, and meanwhile, the nozzle can be closed to realize pause work.

Description

Technical Field

[0001] The utility model relates to a printing device, in particular to a continuously variable 3D printing device. Background Art

[0002] 3D printing technology, also known as additive manufacturing technology, is a technology for creating three-dimensional objects by stacking materials layer by layer. Since the early 1980s, this technology has been developing. Since the 1980s, 3D printing technology has attracted worldwide attention and began to enter people's vision and life. Now, 3D printing technology has been well developed and applied in many fields such as manufacturing, medical, academic, aerospace and military. The basic principle of 3D printing is to add materials layer by layer, and the principle of 3D printing technology is to transform digital design into a solid object. Common 3D printing technologies include fused deposition modeling (FDM), stereolithography (SLA), selective laser sintering (SLS), etc. These technologies stack materials layer by layer in different ways to finally form a three-dimensional object. The most commonly used printing method is fused deposition modeling (FDM). This molding method mainly has two types. One is to use thermoplastic filaments (continuous long fiber composites) as raw materials, and the other is to use thermoplastic particles (discontinuous short fiber composites) as raw materials for printing.

[0003] At present, the thermoplastic pellet materials on the market all use extrusion heads. The pellet materials are put into the mixing cylinder and then heated and melted, and then extruded by a screw. However, there is a problem that the size of the nozzle aperture extruded by the screw is fixed. If it is necessary to change the printing caliber, it is very troublesome. It is necessary to stop the ongoing printing task first and then replace the printing nozzle. It is impossible to continuously change the caliber during the operation of the 3D printer. At the same time, because the size of the printing nozzle aperture is fixed, it will be restricted during printing slicing and path planning, and the printing speed and printing effect will also be restricted. Summary of the Utility Model

[0004] The utility model aims to solve the technical problem of providing a 3D printing device that can change the nozzle aperture.

[0005] To solve the above technical problem, the technical solution of a continuously variable 3D printing device of the utility model is as follows:

[0006] It includes a heating and stirring cylinder; an extrusion screw is rotatably connected inside the heating and stirring cylinder; the outer end of the extrusion screw is connected with a motor for driving the extrusion screw to rotate itself; a feeding pipeline is connected to the side of the heating and stirring cylinder, and a nozzle fixing block is connected to the lower end of the heating and stirring cylinder; a nozzle is installed below the nozzle fixing block; the nozzle includes two nozzle slide rail blocks respectively connected to the front and rear sides below the nozzle fixing block and symmetrically arranged, and two nozzle sliders for controlling the size of the nozzle diameter; the two nozzle sliders are horizontally slidably connected between the two nozzle slide rail blocks, and the two nozzle sliders are symmetrically arranged; mounting panels are connected to the left and right sides of the two nozzle slide rail blocks; a first linear motor and a second linear motor for controlling the horizontal sliding of the two nozzle sliders are respectively connected to the two mounting panels; the first linear motor is connected to one of the nozzle sliders through a first connecting rod, and the second linear motor is connected to the other nozzle slider through a second connecting rod.

[0007] A preheating thermocouple is connected to the upper part of the heating and stirring cylinder; a first high-temperature heating thermocouple and a second high-temperature heating thermocouple are connected to the middle part of the heating and stirring cylinder; an extrusion temperature control thermocouple is connected to the bottom of the heating and stirring cylinder.

[0008] The motor is connected to the extrusion screw through a coupling.

[0009] Symmetrically arranged diversion inclined surfaces for guiding the printing material are provided at the upper ends of the two nozzle sliders.

[0010] The extrusion port formed between the two nozzle slide rail blocks and the two nozzle sliders is square.

[0011] The technical effects that the present utility model can achieve are: the present utility model can continuously adjust the distance between the two nozzle sliders through the first linear motor and the second linear motor, thereby continuously changing the size of the nozzle diameter, so as to adapt to various application scenarios, and can also close the nozzle to achieve pause of work; and the present utility model reduces the resistance of the molten fluid and improves the flow performance and the extrusion effect by setting the diversion inclined surface; the first linear motor and the second linear motor are both controlled by linear motors, which are more sensitive, accurate and convenient. Description of the Drawings

[0012] The following further describes the present utility model in detail with reference to the drawings and specific embodiments:

[0013] Figure 1 is a schematic structural diagram of a continuously variable 3D printing device of the present utility model;

[0014] Figure 2 is a perspective view of a continuously variable 3D printing device of the present utility model;

[0015] Figure 3Yes Figure 2 Enlarged view of part A;

[0016] Figure 4 Partial cross-sectional view of a continuously variable 3D printing device of the present utility model;

[0017] Figure 5 Yes Figure 4 Enlarged view of part B;

[0018] Figure 6 Partial structural schematic diagram of a continuously variable 3D printing device of the present utility model (the mounting panel, the first linear motor, and the second linear motor are removed);

[0019] Figure 7 Yes Figure 6 Enlarged view of part C;

[0020] Figure 8 Structural schematic diagram of the nozzle slider;

[0021] Figure 9 Schematic diagram of the traditional extrusion molding method;

[0022] Figure 10 Schematic diagram of the extrusion molding method of the present utility model. Detailed implementation manners

[0023] The present utility model will be further elaborated in detail below with reference to the accompanying drawings.

[0024] Refer to Figures 1 to 10 .

[0025] A continuously variable 3D printing device, comprising a heating and stirring cylinder 5, in which an extrusion screw 4 is rotatably connected. The outer end of the extrusion screw 4 is connected to a motor 1 for driving the extrusion screw 4 to rotate itself. Specifically, the motor 1 is connected to the extrusion screw 4 through a coupling 2; a feeding pipe 6 is connected to the side of the heating and stirring cylinder 5, and a nozzle fixing block 11 is connected to the lower end of the heating and stirring cylinder 5. A nozzle is installed below the nozzle fixing block 11. The nozzle includes two nozzle slide rail blocks 12 symmetrically arranged and respectively connected to the front and rear sides below the nozzle fixing block 11 and two nozzle sliders 13 for controlling the size of the nozzle diameter; specifically, the extrusion port formed between the two nozzle slide rail blocks 12 and the two nozzle sliders 13 is square, and symmetrically arranged guiding inclined surfaces 22 for guiding the printing material are provided at the upper ends of the two nozzle sliders 13; the two nozzle sliders 13 are horizontally slidably connected between the two nozzle slide rail blocks 12 and are symmetrically arranged; both the left and right sides of the two nozzle slide rail blocks 12 are connected with mounting panels 21; a first linear motor 14 and a second linear motor 17 for controlling the horizontal sliding of the two nozzle sliders 13 are respectively connected to the two mounting panels 21; the first linear motor 14 is connected to one of the nozzle sliders 13 through a first connecting rod 15, and the second linear motor 17 is connected to the other nozzle slider 13 through a second connecting rod 16; a preheating thermocouple 7 is connected to the upper part of the heating and stirring cylinder 5; a first high-temperature heating thermocouple 8 and a second high-temperature heating thermocouple 9 are connected to the middle part of the heating and stirring cylinder 5, and an extrusion temperature control thermocouple 10 is connected to the bottom of the heating and stirring cylinder 5.

[0026] When the utility model is in use: First, control the preheating thermocouple 7, the first high-temperature heating thermocouple 8, the second high-temperature heating thermocouple 9, and the extrusion temperature control thermocouple 10. After the temperature reaches the preset temperature, start to put the printing raw material into the feeding pipeline 6; at the same time, the motor 1 starts to rotate (the motor 1 of the utility model is a servo motor). The motor 1 is connected by a coupling 2 and drives the extrusion screw 4. Then the extrusion screw 4 pushes the put printing raw material. When the printing raw material passes through the heating area, it is transformed from solid granular material into a molten fluid. The extrusion screw 4 not only pushes the printing raw material but also plays a role in stirring the raw material. The extrusion screw 4 can effectively reduce the pores when the printing raw material is formed, so as to enhance the strength of the formed model; when the melted raw material passes through the nozzle fixing block 11, its shape becomes an extrusion material with a rectangular cross-section. The nozzle slide rail block 12 is fixed on the nozzle fixing block 11. The two nozzle slide rail blocks 12 provide two parallel slide rails, and there are linear high-temperature resistant sealing strips on the two slide rails, which effectively prevent the molten raw material from flowing into the slide rails; the nozzle slider 13 is embedded in the slide rails of the nozzle slide rail block 12. The part where the nozzle slide rail block 12 contacts the nozzle fixing block 11 adopts a diversion inclined plane 22 design transition structure, which is more convenient for the molten material to flow into the nozzle; the two nozzle sliders 13 are respectively connected to the first linear motor 14 and the second linear motor 17 through the first connecting rod 15 and the second connecting rod 16, and the telescopic amount is controlled by the first linear motor 14 and the second linear motor 17, so as to control the position of the nozzle slider 13 (that is, control the distance between the two nozzle sliders 13), so as to achieve the purpose of continuously changing the nozzle diameter, and at the same time, the nozzle can be closed when it is not in use to prevent the molten raw material from dripping out.

[0027] The nozzle of the utility model can be continuously changed. Then, for different models and different wall thicknesses of the models, by setting the nozzle diameter, the printing speed and efficiency can be greatly improved; because for the traditional fixed print head, the nozzle diameter is related to the minimum value of the printing wall thickness. When printing a model with a relatively large wall thickness, the printer needs to plan the path several more times to ensure that the printed model is consistent with the original model, resulting in an increase in the overall path of the printer, and then the printing speed will decrease accordingly; when using a continuously variable printing nozzle, it can be automatically adjusted according to different wall thicknesses, and then the number of path planning can be reduced accordingly, so as to effectively improve the printing speed.

[0028] When using a continuously variable nozzle, the strength of the printed model can also be improved; the traditional nozzle has a fixed aperture, so more divisions are required during path planning. In the 3D printing deposition melting type, the inter-filament porosity, which most affects the printing quality, is such that the larger the inter-filament porosity, the lower the strength. By using a continuously variable nozzle, when the wall thickness of the model changes, the inter-filament porosity can be effectively reduced. Traditionally, it may take two or three passes to form, but the variable nozzle can achieve one-pass forming, so the inter-filament porosity can be greatly reduced, thereby greatly improving the strength of the printed model. At the same time, in the present invention, the shape of the extrusion outlet of the nozzle is square, and the inter-filament gap will be further reduced, so the printing strength of the model is further improved.

[0029] This technology can also improve the strength of the printed model by enhancing the degree of inter-filament fusion. Because the traditional nozzle has a fixed aperture and requires multiple path planning to form, the filaments printed first will solidify first. Since the filaments printed later and the filaments printed first have different solidification degrees due to different temperatures, the fusion and adhesion effect between the two is not good. However, if a new type of variable-aperture nozzle is used and printed directly through the nozzle, the degree of inter-filament adhesion can be effectively improved, thereby effectively enhancing the strength of the printed model.

[0030] The present utility model can also solve the problem that cannot be closed by traditional nozzles. The aperture size of the traditional nozzle cannot be changed, but the extruded material is a molten fluid, which may automatically drip out under the action of gravity, resulting in the appearance of raw material pores at the nozzle, affecting the next printing step. However, when the aperture of the printing nozzle of the present invention can be changed, during the switching or pausing of the printing step, it can be driven by the first linear motor 14 and the second linear motor 17 to directly close the extrusion outlet of the nozzle to prevent the outflow of raw materials.

[0031] On the other hand, the present utility model brings benefits. When the aperture needs to be changed, manual removal is required. Since the printing raw material at the nozzle has solidified into a solid under the condition of cooling, it cannot be removed, and it can only be removed and replaced under the high-temperature state of the nozzle. This will not only delay the working time, but also increase the labor intensity of the workers and expose the workers to the risk of being scalded. Therefore, the present invention can effectively change these situations, creating great social benefits and improving the work safety of the workers.

Claims

1. A continuously variable 3D printing device, comprising a heating and stirring cylinder (5); an extrusion screw (4) is rotatably connected inside the heating and stirring cylinder (5); the outer end of the extrusion screw (4) is connected to a motor (1) for driving the extrusion screw (4) to rotate itself; a feeding pipe (6) is connected to the side of the heating and stirring cylinder (5), and it is characterized in that: The lower end of the heating and stirring cylinder (5) is connected to a nozzle fixing block (11); a nozzle is installed below the nozzle fixing block (11); the nozzle includes two nozzle slide rail blocks (12) respectively connected to the front and rear sides below the nozzle fixing block (11) and symmetrically arranged, and two nozzle slider blocks (13) for controlling the size of the nozzle diameter; the two nozzle slider blocks (13) are horizontally slidably connected between the two nozzle slide rail blocks (12), and the two nozzle slider blocks (13) are symmetrically arranged; mounting panels (21) are connected to the left and right sides of the two nozzle slide rail blocks (12); a first linear motor (14) and a second linear motor (17) for controlling the horizontal sliding of the two nozzle slider blocks (13) are respectively connected to the two mounting panels (21); the first linear motor (14) is connected to one of the nozzle slider blocks (13) through a first connecting rod (15), and the second linear motor (17) is connected to the other nozzle slider block (13) through a second connecting rod (16).

2. The continuous variable 3D printing device according to claim 1, wherein: A preheating thermocouple (7) is connected to the upper part of the heating and stirring cylinder (5); a first high-temperature heating thermocouple (8) and a second high-temperature heating thermocouple (9) are connected to the middle part of the heating and stirring cylinder (5); an extrusion temperature control thermocouple (10) is connected to the bottom of the heating and stirring cylinder (5).

3. A continuously variable 3D printing device according to claim 1, characterized in that: The motor (1) is connected to the extrusion screw (4) through a coupling (2).

4. A continuously variable 3D printing device according to claim 1, characterized in that: Symmetrically arranged diversion inclined surfaces (22) for guiding the printing material are provided at the upper ends of the two nozzle slider blocks (13).

5. A continuously variable 3D printing device according to claim 1, wherein: The extrusion port formed between the two nozzle slide rail blocks (12) and the two nozzle slider blocks (13) is square.

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