A vacuum environment 3D printing forming nozzle

Abstract

The present invention discloses a vacuum environment 3D printing forming nozzle, including a motor assembly, an extruder, a guide tube, a heating assembly, a heat insulation frame, a nozzle and a standard pneumatic joint; the motor assembly is fixed on the back of the extruder, the extruder is driven by the motor assembly, and the standard pneumatic joint is fixed on the top of the extruder; the lower part of the extruder is fixedly connected to the heating assembly through the heat insulation frame, the guide tube is fixed to the bottom of the extruder, and is located inside the heat insulation frame and fixed to the heating assembly; the nozzle is fixed to the bottom of the heating assembly; the heating assembly is fixedly connected to the existing heat dissipation block, and the original convection heat dissipation structure is changed to a radial radiation heat dissipation structure. The present invention is suitable for the on-orbit environment of space, has a simple and reliable structure, a small number of parts, and a reasonable structural temperature distribution.

Description

Technical Field

[0001] The present invention relates to the technical field of additive manufacturing, and in particular to a 3D printing forming nozzle in a vacuum environment. Background Art

[0002] 3D printing, also known as additive manufacturing, can quickly manufacture complex parts based on digital models by building entities layer by layer without the need for molds. Among them, the most widely used molding process is the molding of thermoplastic high-performance resins through material extrusion.

[0003] Composite materials have the characteristics of high strength, high modulus, and low density, and have broader application prospects than single high-performance resin materials. Especially in the field of aerospace, they can be used to manufacture large-volume components such as solar panels, radar antennas, and large trusses that are not convenient to launch from the ground.

[0004] The following limitations must be considered when applying 3D printing technology of high-performance resins and composites to the on-orbit environment:

[0005] 1) The in-orbit forming process is in a vacuum environment. The forced air cooling convection heat dissipation method widely used on the ground for the nozzle heat sink is not applicable in the space environment. In the space environment, this heat dissipation method is almost completely isolated, and heat conduction becomes the main heat dissipation method. The structure temperature will be higher than that of the ground environment, making it difficult to ensure the reasonable distribution of the nozzle temperature during printing.

[0006] 2) The existing print head is composed of multiple parts, with too many parts, and there are many bolt connection methods and connecting bolts, which further increases the number of components. Too many parts will increase the probability of error in the space environment;

[0007] In view of the above limiting factors, it is of great significance and value to develop a 3D printing nozzle that is suitable for the on-orbit environment of space, has a simple and reliable structure, a small number of parts, and a reasonable structural temperature distribution. Summary of the invention

[0008] In view of this, the present invention provides a vacuum environment 3D printing forming nozzle, which is suitable for the on-orbit environment of space, has a simple and reliable structure, a small number of parts, and a reasonable structural temperature distribution.

[0009] The technical solution adopted by the present invention is as follows:

[0010] A vacuum environment 3D printing forming nozzle, comprising a motor assembly, an extruder, a guide tube, a heating assembly, a heat insulation frame, a nozzle and a standard pneumatic joint;

[0011] The motor assembly is fixed on the back of the extruder, the extruder is driven by the motor assembly, and the standard pneumatic joint is fixed on the top of the extruder;

[0012] The bottom of the extruder is fixedly connected to the heating assembly through a heat insulation frame, the guide tube is fixed to the bottom of the extruder, located inside the heat insulation frame, and fixed to the heating assembly; the nozzle is fixed to the bottom of the heating assembly;

[0013] The heating assembly is fixedly connected to the existing heat dissipation block, and the original convection heat dissipation structure is changed into a radial radiation heat dissipation structure.

[0014] Further, the heating assembly includes a heating block, a heating rod and a thermocouple;

[0015] A radiation heat sink is provided on the upper part of the heating block, and the radiation heat sink is interference-fitted with the guide tube; a space for installing a heating rod and a thermocouple is reserved at the lower part; the heating rod and the thermocouple are transitionally matched with the heating block.

[0016] Furthermore, there are two heating rods and two thermocouples, and the heating rods / thermocouples are symmetrically arranged about the midline where the nozzle is located.

[0017] Furthermore, the heating block is connected to the heat insulation frame through a hollow circular tube, and bosses are provided at the four corners of the top of the heating block.

[0018] Furthermore, the upper heat dissipation part of the heating block is plated with black zinc, and the lower heating part is plated with nickel.

[0019] Furthermore, the guide tube and the heat insulation frame are both surface-plated with black zinc.

[0020] Furthermore, a screw is arranged perpendicular to the axial direction of the heating rod and the thermocouple, and the position of the screw is limited by the nut of the screw.

[0021] Beneficial effects:

[0022] 1. The 3D printing forming nozzle of the present invention is suitable for the extreme environment of space. The heating component and the existing heat sink are designed as an integrated whole to reduce the number of parts and provide reliability guarantee for space environment operation. At the same time, the convection heat dissipation structure used in the traditional heat sink is changed to a radial radiation heat dissipation structure, which can achieve efficient heat dissipation in a vacuum environment and ensure that the temperature distribution of various parts of the printing nozzle is reasonable during the printing process, ensure that the wire feeding process is smooth and stable, and ensure that the resin material does not melt in the heat dissipation part on the upper part of the heating component.

[0023] 2. There are two heating rods and two thermocouples. The double heating rods heat symmetrically on both sides of the material melting chamber. This can ensure uniform heating and rapid melting of the material under high vacuum conditions in space and poor heat transfer conditions, thereby ensuring the stability of the material forming process. One of the sets can also be used as a backup to provide support for the reliability of the printing nozzle in the space environment.

[0024] 3. The heating block is connected to the insulation frame through a hollow circular tube to reduce the heat conduction channel and increase the heat dissipation area; bosses are provided at the four corners of the top of the heating block so that the heating block and the insulation frame are not in complete contact, leaving a gap to reduce the heat conduction channel.

[0025] 4. The upper heat dissipation part of the heating block is plated with black zinc to increase the surface emissivity; the lower heating part of the heating block is plated with nickel to reduce heat loss and power consumption.

[0026] 5. The guide tube and the insulation frame are both treated with black zinc plating to increase the surface emissivity and further ensure the rationality of the temperature gradient. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the overall assembly structure of the present invention.

[0028] Figure 2 Schematic diagram of the extruder assembly structure.

[0029] Figure 3 Schematic diagram of the heating block structure.

[0030] Among them, 1-stepping motor, 2-motor seat, 3-guide tube, 4-heating block, 5-heating rod, 6-nozzle, 7-thermocouple, 8-insulation frame, 9-extruder, 10-standard pneumatic connector, 9-1-wire feeding wheel, 9-2-U-groove roller, 9-3-preload slider, 9-4-preload spring, 9-5-preload screw, 9-6-extruder body, 9-7-extruder front cover. DETAILED DESCRIPTION

[0031] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0032] The present invention provides a vacuum environment 3D printing forming nozzle, such as Figure 1 As shown, it includes a motor assembly, an extruder 9, a guide tube 3, a heating assembly, a heat insulation frame 8, a nozzle 6 and a standard pneumatic joint 10; wherein the motor assembly includes a stepper motor 1 and a motor base 2; the heating assembly includes a heating block 4, a heating rod 5 and a thermocouple 7.

[0033] The stepper motor 1 is fixed on the motor base 2, the motor base 2 is fixed to the back of the extruder 9 by screw connection, the extruder 9 is driven by the stepper motor 1, and the standard pneumatic connector 10 is fixed to the top of the extruder 9 by threaded connection.

[0034] like Figure 2As shown, the extruder 9 includes a wire feeding wheel 9-1, a U-groove roller 9-2, a pre-tightening slider 9-3, a pre-tightening spring 9-4, a pre-tightening screw 9-5, an extruder body 9-6 and an extruder front cover 9-7; the U-groove roller 9-2 is fixed on the back of the pre-tightening slider 9-3, and a bearing is provided inside the U-groove roller 9-2 for rotation; the pre-tightening screw 9-5 is fixed between the pre-tightening slider 9-3 and the extruder body 9-6, and the pre-tightening screw 9-5 provides a pre-tightening force for the pre-tightening slider 9-3. The pre-tightening spring 9-4 is sleeved on the pre-tightening screw 9-5; the installation direction of the pre-tightening screw 9-5 is perpendicular to the rotation center axis of the U-groove roller 9-2; by adjusting the pre-tightening spring 9-4 and the pre-tightening screw 9-5, the relative position of the U-groove roller 9-2 and the wire feeding wheel 9-1 can be adjusted. The extruder front cover 9-7 is fixed on the extruder body 9-6 by screws and is located on the front of the pre-tightening slider 9-3. A groove is provided on the extruder front cover 9-7, and the groove is installed in cooperation with the positioning boss on the front side of the extruder body 9-6.

[0035] The wire feeding wheel 9-1 of the extruder 9 is fixed on the motor shaft of the stepping motor 1 by a set screw, and the wire feeding wheel 9-1 is driven by the stepping motor 1 to rotate. The wire feeding wheel 9-1 drives the material to move, and the material drives the U-groove roller 9-2 to rotate.

[0036] The extruder 9 is fixedly connected to the heating block 4 through the insulation frame 8 below, and the heating block 4 is connected to the insulation frame 8 through a hollow circular tube. Bosses are provided at the four corners of the top of the heating block 4, so that the heating block 4 is not completely in contact with the insulation frame 8, leaving a gap to reduce the heat conduction channel.

[0037] The guide tube 3 is fixed to the bottom of the extruder 9 by a threaded connection, and is located inside the heat insulation frame 8. It is connected to the heating block 4 by a threaded connection and communicates with the material melting chamber (located inside the heating block 4); four radiation heat sinks are provided on the upper part of the heating block 4, and the radiation heat sinks are interference fit with the guide tube 3 for heat dissipation of the guide tube 3; the lower part is reserved for the installation space of the heating rod 5 and the thermocouple 7; there are two heating rods 5 and two thermocouples 7, and the heating rods 5 / thermocouples 7 are symmetrically arranged about the midline where the nozzle 6 is located (i.e., on both sides of the material melting chamber), which can be used at the same time to ensure stability, or one of the groups can be used as a backup to provide support for the reliability of the printing nozzle in the space environment. The heating rod 5 and the thermocouple 7 are both transitionally matched with the heating block 4. At the same time, a screw is set perpendicular to the axial direction of the heating rod 5 and the thermocouple 7, and its position is limited by the nut of the screw. The nozzle 6 is fixed to the lower end of the heating block 4 by a threaded connection and communicates with the material melting chamber.

[0038] The heat insulating frame 8 is made of a material with a relatively low thermal conductivity, so as to prevent the excessive heat generated by the heating block 4 from being conducted to the stepping motor 1. The heat insulating frame 8 adopts a hollow circular tube structure, so as to further reduce the heat conduction channel and increase the heat dissipation area.

[0039] like Figure 3As shown, the heating block 4 is designed as an integral unit with the existing heat dissipation block, and the two parts are connected by a hollow circular tube while ensuring the strength. The original convection heat dissipation structure is changed to a radial radiation heat dissipation structure, which is composed of four vertical radiation plates.

[0040] In order to further ensure the reasonableness of the temperature gradient, the guide tube 3 and the heat insulation frame 8 are both plated with black zinc to increase the surface emissivity. The upper heat dissipation part of the heating block 4 is also plated with black zinc, and the lower heating part is plated with nickel to reduce the heat loss of this part and reduce power consumption.

[0041] The temperature distribution of each part of the print head of the present invention is reasonable, which can ensure that the material is below the glass transition temperature of the material in the guide tube 3 and above after entering the print head. The heat dissipation part of the resin material on the upper part of the heating block 4 does not melt.

[0042] In summary, the above are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A vacuum environment 3D printing forming nozzle, characterized in that: Includes motor assembly, extruder, guide tube, heating assembly, thermal insulation frame, nozzle and standard pneumatic connector; The motor assembly is fixed on the back of the extruder, the extruder is driven by the motor assembly, and the standard pneumatic joint is fixed on the top of the extruder; The bottom of the extruder is fixedly connected to the heating assembly through a heat insulation frame, the guide tube is fixed to the bottom of the extruder, located inside the heat insulation frame, and fixed to the heating assembly; the nozzle is fixed to the bottom of the heating assembly; The heating assembly is fixedly connected to the existing heat dissipation block, and the original convection heat dissipation structure is changed into a radial radiation heat dissipation structure; The heating assembly includes a heating block, a heating rod and a thermocouple; A radiation heat sink is provided on the upper part of the heating block, and the radiation heat sink is interference-fitted with the guide tube; a space for installing a heating rod and a thermocouple is reserved at the lower part; the heating rod and the thermocouple are transitionally matched with the heating block; There are two heating rods and two thermocouples, and the heating rods / thermocouples are symmetrically arranged about the center line of the nozzle; The heating block is connected to the heat insulation frame through a hollow circular tube, and bosses are provided at the four corners of the top of the heating block; The upper heat dissipation part of the heating block is subjected to black zinc plating, and the lower heating part is subjected to nickel plating.

2. The vacuum environment 3D printing forming nozzle according to claim 1, characterized in that: The guide tube and the heat insulation frame are both surface-plated with black zinc.

3. The vacuum environment 3D printing forming nozzle according to claim 1, characterized in that: A screw is arranged perpendicular to the axis direction of the heating rod and the thermocouple, and the position of the screw is limited by the nut of the screw.

4. The vacuum environment 3D printing forming nozzle as claimed in claim 2, characterized in that: A screw is arranged perpendicular to the axis direction of the heating rod and the thermocouple, and the position of the screw is limited by the nut of the screw.

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