CN108839345B

CN108839345B - 3D print head

Info

Publication number: CN108839345B
Application number: CN201810886279.6A
Authority: CN
Inventors: 张海强; 杜俊斌; 赵建华; 陈晓佳
Original assignee: Guangzhou Electronic Technology Co Ltd
Current assignee: Guangzhou Electronic Technology Co Ltd
Priority date: 2018-07-26
Filing date: 2018-08-06
Publication date: 2021-03-02
Anticipated expiration: 2038-08-06
Also published as: CN108839345A

Abstract

The invention discloses a 3D printer nozzle which comprises a substrate, a heat dissipation block, an air cooling system and at least one melting wire discharging assembly, wherein the heat dissipation block is arranged below the substrate, the upper part of the melting wire discharging assembly is connected with the substrate, the middle part of the melting wire discharging assembly is connected with the heat dissipation block, and the air cooling system is arranged on the substrate and used for cooling and dissipating the heat dissipation block and the melting wire discharging assembly. According to the invention, the melting wire outlet assembly is cooled by the heat dissipation block, the heat transfer is accelerated by the air cooling system, and the premature softening of the wire material can be effectively avoided, so that the wire feeding resistance of the spray head can be reduced, and the risk of blockage of the spray head can be reduced.

Description

3D print head

Technical Field

The invention relates to the technical field of 3D printing, in particular to a 3D printer nozzle.

Background

The 3D printing technology is one of rapid prototyping technologies, and is a technology for constructing an object by stacking modeling materials layer by layer according to a program on the basis of a digital model file. The Fused Deposition Modeling (FDM) technology is a 3D printing technology that is currently used in many applications, and melts a thermoplastic material into a molten state at a high temperature, and then solidifies after being extruded by a print head, and finally, the molten material is stacked in a three-dimensional space to form a three-dimensional object.

The printing nozzle serving as one of the 3D printing and forming core components is of vital importance to the 3D printing effect in performance and reliability, and the printing nozzle with a fine design can improve the surface quality and forming precision of sample printing and can greatly improve the stability and production benefit of the printer.

However, in the current fused deposition modeling 3D printers, the problems of unsmooth wire discharge, nozzle blockage and the like easily occur in the printing process, and most of the reasons are that the wire material is softened too early due to the unreasonable structural design of the nozzle and poor heat dissipation of the heat dissipation end of the nozzle, so that the abnormal wire discharge of the nozzle is finally caused by the excessively large wire feeding resistance of the nozzle.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides the 3D printer nozzle which can effectively shorten the high elastic state length of the filament in the printer nozzle, reduce the wire feeding resistance and improve the surface quality and the forming precision of sample printing.

In order to achieve the purpose, the technical scheme of the invention is as follows:

the utility model provides a 3D print head, includes base plate, radiating block, air cooling system and at least one melting silk subassembly, and the radiating block is installed in the below of base plate, and the upper portion and the base plate that the silk subassembly was gone out in the melting are connected, and the middle part is connected with the radiating block, and the air cooling system mounting is on the base plate, goes out the silk subassembly to radiating block and melting and cools off the heat dissipation.

The melting wire outlet assembly is cooled through the heat dissipation block, the air cooling system accelerates the heat transfer, the premature softening of the wire materials can be effectively avoided, the wire feeding resistance of the spray head can be reduced, and the printing efficiency is improved.

As an improvement of the invention, the melting wire-discharging assembly comprises a throat pipe, a nozzle, a heat storage block, a heating rod, a heat insulation piece and a joint, wherein the upper end of the heat insulation piece is connected with a base plate, the lower end of the heat insulation piece extends into a heat dissipation block and is connected with the upper end of the throat pipe, the lower end of the throat pipe is connected with the heat storage block, the nozzle is arranged below the heat storage block, the heating rod is arranged in the heat storage block, the joint is arranged on the upper end surface of the heat insulation piece, the heat insulation piece and the joint are of tubular hollow structures, and the joint, the heat insulation piece, the throat pipe and the nozzle.

The throat pipe is only provided with one section of the contact heat storage block below, the heat dissipation block is connected with the heat insulation piece, the heat of the heat storage block can be effectively prevented from being upwards transferred through the throat pipe, so that the high elastic state length of the silk material in the silk material circulation channel can be shortened, the piston effect of the silk material is enhanced, and the silk feeding resistance is reduced.

Furthermore, the upper end of the nozzle is provided with an inner hole matched with the lower end of the throat pipe, and when the nozzle is screwed on the heat storage block from bottom to top, the bottom surface of the inner hole of the nozzle is tightly attached to the lower end surface of the throat pipe. Thus, the connection tightness is ensured, and the leakage of the molten wire is prevented; meanwhile, the outer diameter of the throat pipe is in cylindrical nested fit with the inner hole of the nozzle, so that the assembly requirement is reduced, and the coaxiality of the throat pipe and the nozzle is improved.

Furthermore, in order to accurately control the melting temperature of the filament materials, a temperature sensor is arranged in the heat storage block.

Furthermore, a section of the throat pipe close to the upper end face of the heat storage block is provided with a contraction section with the suddenly reduced outer diameter. The design can reduce the heat conduction of the heat storage block to the throat pipe above the contraction section, so that the heat of the heating rod is kept in the heat storage block and the nozzle as much as possible, the temperature step of the silk material circulation channel is enlarged, and the high elastic state length of the silk material is further reduced.

Further, the heat insulation piece is made of polytetrafluoroethylene or polyether ether ketone. The high-temperature-resistant high-stability lubricating oil has the characteristics of high temperature resistance, high stability and high lubrication, and can reduce the friction resistance and elastic deformation of the silk material during passing.

Furthermore, the upper part of the heat dissipation block is provided with long thin fins which are regularly arranged. The structure of the long and thin fins can increase the heat dissipation surface area, thereby being beneficial to the circulating heat dissipation of an air cooling system and improving the cooling efficiency.

As an improvement of the invention, the air cooling system comprises a turbofan and an axial flow fan, wherein the turbofan is arranged behind the heat dissipation block, and the axial flow fan is arranged in front of the heat dissipation block. The turbine fan and the centrifugal fan form a semi-circulating air cooling mode, and cooling efficiency can be greatly improved.

Furthermore, the air cooling system also comprises an axial flow fan air deflector and an angle adjusting plate for adjusting the installation angle of the axial flow fan, wherein the axial flow fan is installed on the base plate through the angle adjusting plate, and the axial flow fan air deflector is installed at the bottom of the axial flow fan and used for guiding cold air of the axial flow fan to the contraction section of the throat pipe.

One part of cold air blown by the axial flow fan flows along the direction of the fins of the heat dissipation block, and the other part of the cold air forcibly cools a contraction section of the throat pipe between the heat storage block and the heat dissipation block, so that the softening length of the silk material before entering the heat storage block is shortened as much as possible, and the risk of blockage of the spray head is reduced.

Furthermore, the air cooling system also comprises a turbine fan air deflector arranged at the bottom of the turbine fan and used for guiding the cold air of the turbine fan to the position below the nozzle. The turbo fan blows air to the surface of the model printed below the nozzle, so that the cooling speed of the extruded molten wire can be increased, and the printing precision and the surface quality of the model can be improved.

Compared with the prior art, the invention has the following advantages:

1. the throat pipe and the heat insulation piece in the melting wire outlet assembly are cooled through the heat dissipation block, so that the heat of the heat storage block can be effectively prevented from being transferred upwards through the throat pipe, the softening length of a wire material before entering the heat storage block is shortened as much as possible, and the risk of blockage of a spray head is reduced.

2. The radiating block adopts the structure that the bottom has certain thickness, upper portion is long thin fin, both increases the area of contact with the upper end of the throat, does benefit to the quick conduction of heat of the upper end of the throat, also increases the fastness of being connected of throat and radiating block simultaneously, and the structure of the long thin fin on upper portion can also increase heat radiating surface area, is favorable to the circulation heat dissipation of air cooling system, improves cooling efficiency.

3. The joints, the heat insulation pieces, the throat and the nozzle are all in a nested connection structure, so that the coaxiality of the central material hole is improved, and the risk of overflow of molten silk materials is reduced.

4. The double-fan structure of the axial flow fan for blowing and the turbofan for exhausting is designed, so that the convection heat dissipation effect of the heat dissipation fins is effectively accelerated, and the heat accumulation of the heat dissipation blocks is reduced.

5. Partial wind beams are guided out by the axial flow fan air deflector to flow between the heat storage block and the heat dissipation block, so that the influence of heat radiation of the hot end on the heat dissipation end is reduced.

6. The turbine fan air deflector blows air to the surface of the model printed below the nozzle, so that the cooling speed of the extruded molten wire is increased, and the printing precision and the surface quality of the model are improved.

Drawings

FIG. 1 is an isometric view of a 3D printer head;

FIG. 2 is a front cross-sectional view of a 3D printer head (hidden air cooling system);

FIG. 3 is a cross-sectional view of a melter melting a filament assembly;

FIG. 4 is a sectional view of the throat and the heat sink in a fixed manner;

FIG. 5 is a schematic structural view of a heat slug;

FIG. 6 is a schematic view of an air cooling system;

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

As shown in fig. 1 to 4, a 3D printer nozzle includes a substrate 1, a connection column 2, a heat dissipation block 3, an air cooling system 4, and two melting wire discharging assemblies 5 symmetrically installed in left and right directions. The substrate 1 is a mounting plate of the whole printing spray head, and all parts are directly or indirectly mounted on the mounting plate; the radiating block 3 is fixed below the substrate 1 through a plurality of connecting columns 2 which are uniformly arranged, the melting wire discharging assembly 5 is fixedly connected with the substrate 1 and the radiating block 3 respectively, the air cooling system 4 is arranged at the front end and the rear end of the substrate 1, and air openings are aligned with the radiating block 3 and the corresponding positions of the melting wire discharging assembly 5 respectively to form efficient heat dissipation of the melting wire discharging assembly 5.

The melt-out wire assembly 5 includes a throat 501, a nozzle 502, a heat storage block 503, a temperature sensor 504, a heating rod 505, insulation 506, and a joint 507. Wherein throat 501, nozzle 502, heat storage block 503, temperature sensor 504, and heating rod 505 are collectively referred to as a melter. The lower end of the throat pipe 501 is inserted into a matching hole of the heat storage block 503 and is screwed and fixed on the heat storage block 503 by screws, the upper end of the throat pipe 501 penetrates through a matching hole on the heat dissipation block 3 in a sliding mode and is adjusted to a proper position, then the screws are screwed and fixed on the heat dissipation block 3 (detailed figure 4), and when the throat pipe 501 is connected with the heat storage block 503, heat at the upper end of the throat pipe 501 can be quickly guided to the surface of the heat dissipation block 3 to be dissipated, so that the softening length of wires in the throat pipe 501 is shortened. In order to ensure the melting efficiency of the melting device on the filament materials and reduce the transmission of heat to the upper end part of the throat pipe 501, under the condition of meeting the connection strength, a section of the throat pipe 501, which is positioned on the upper end surface of the heat storage block 503, is designed into a thin-wall structure, namely a contraction section L with the suddenly reduced outer diameter is formed. The nozzle 502 is screwed into the matching hole of the heat storage block 503 from bottom to top, and the inner step surface of the nozzle is tightly attached to the lower end surface of the throat 501, so that the tightness of connection with the throat 501 can be ensured, and the leakage of molten silk materials is prevented; meanwhile, the outer diameter of the throat pipe 501 is in cylindrical nested fit with the inner hole of the nozzle 502, so that the assembly requirement is reduced, and the coaxiality of the throat pipe 501 and the inner hole of the nozzle 502 is improved. The heating rod 505 and the temperature sensor 504 are installed and fixed in the heat storage block 503 from the side; in order to improve the heating efficiency of the heating rod 505 and prolong the service life, the heating rod 505 is designed and fixed at a position close to the melting channel, and the heating section is completely contacted with the heat storage block 503, so that the melting effect of the heat storage block 503 on the filament materials is improved. The heat insulation piece 506 and the joint 507 are tubular hollow structures, the lower end of the heat insulation piece 506 is sleeved into the throat 501 and attached to the top end face of the throat 501, and the joint 507 is screwed on the upper end face of the throat after the upper end of the heat insulation piece is screwed and fixed on the substrate 1. After the installation, the joint 507, the heat insulator 506, the throat 501 and the central hole of the nozzle 502 are arranged on the same axis to form a silk material flowing channel. In order to reduce the influence of the temperature of the top end of the throat pipe 501 on the filament material, the heat insulation member 506 is made of high-performance engineering plastics with high temperature resistance, high stability and high lubrication, and the friction resistance and the elastic deformation of the filament material during passing are reduced, for example, polytetrafluoroethylene, polyether ether ketone resin and the like are good choices.

As shown in fig. 5, the heat dissipation block 3 has to satisfy both good heat conduction to the throat 501 and fast heat dissipation. For this purpose, the heat dissipation block 3 is designed to have a structure with a certain thickness at the bottom and long thin fins 301 at the upper part; the bottom of the throat tube 501 is provided with a certain thickness, so that the contact area between the throat tube 501 and the upper end part of the throat tube 501 can be increased, the heat at the upper end part of the throat tube 501 can be quickly transmitted to the radiating block 3, and meanwhile, the firmness of connection between the throat tube 501 and the radiating block 3 can be increased; the structure of the long thin fins 301 on the upper part can increase the heat dissipation surface area, which is beneficial to the circulation heat dissipation of the air cooling system 4 and improves the cooling efficiency.

As shown in fig. 1 and 6, the air cooling system 4 is a semi-circulation type air cooling device mainly composed of a turbofan 401, a turbofan air deflector 402, an angle adjustment plate 403, an axial fan 404, and an axial fan air deflector 405. The axial flow fan 404 is arranged in front of the melt wire discharging assembly 5 and fixed on the front end surface of the substrate 1 through an angle adjusting plate 403, the axial flow fan air deflector 405 is of an L-shaped plate structure facing the melt wire discharging assembly 5 and is arranged at the bottom of the axial flow fan 404, and the air outlet direction of the axial flow fan air deflector 405 can be adjusted by changing the size of a break angle of the angle adjusting plate 403; one part of cold air blown by the axial flow fan 404 flows along the direction of the long thin fins 301 of the heat dissipation block 3, and the other part of cold air is forced to cool the contraction section L of the throat pipe 501 through the axial flow fan air deflector 405, so that the softening length of the silk material before entering the heat storage block 503 is shortened as much as possible, and the risk of nozzle blockage is reduced. The turbofan 401 is arranged behind the melting wire outlet assembly 5 and is mounted and connected to the rear end face of the substrate 1 through a fixing hole at the upper end of the turbofan 401, the turbofan air deflector 402 is mounted at the bottom of the turbofan 401, an air inlet of the turbofan is communicated with an air outlet at the bottom of the turbofan 401, and an air suction inlet of the turbofan 401 is opposite to the close-contact radiating block 3, so that the effect of increasing the heat dissipation of the radiating block 3 at the fastest speed is achieved; the air outlet of the turbofan air deflector 402 faces the lower part of the nozzle 502, and cold air blown by the axial flow fan 404 enters the turbofan 401 after passing through the heat dissipation block 3 and is blown to the surface of the printed model below the nozzle 502 by the turbofan air deflector 402, so that the cooling speed of the extruded molten wires is increased, and the printing precision and the surface quality of the model are improved. The air cooling system 4 is designed into a double-fan structure with an axial flow fan 404 for blowing air and a turbofan 401 for exhausting air, so that the convection heat dissipation effect of the heat dissipation block 3 can be obviously accelerated, and the heat accumulation at the heat dissipation end is reduced; the wind current that axial fan aviation baffle 405 drainage goes out passes through between heat accumulation piece 503 and radiating block 3, can reduce the influence of high temperature end heat radiation to the radiating end.

When the 3D printer nozzle works, wires pass through the joint 507, the heat insulation piece 506 and the throat 501, are melted in the heat storage block 503 and then are extruded out through the nozzle 502, and the air cooling system 4 carries out forced cooling on the heat dissipation block 3 and the contraction section L of the throat 501, so that the wires are prevented from being softened prematurely at the feeding end of the printer nozzle, the risk of nozzle blockage is reduced, and the reliability of the printer nozzle is improved.

It should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "inner", "outer", "top", "bottom", and the like in the present embodiment indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing embodiments of the present invention and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be configured in a specific orientation, and operate, and thus, should not be construed as limiting the embodiments of the present invention.

The above embodiments are only for illustrating the technical concept and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement the present invention accordingly, and not to limit the protection scope of the present invention accordingly. All equivalent changes or modifications made in accordance with the spirit of the present disclosure are intended to be covered by the scope of the present disclosure.

Claims

1. The utility model provides a 3D print head which characterized in that: the cooling device comprises a substrate (1), a radiating block (3), an air cooling system (4) and at least one melting wire discharging assembly (5), wherein the radiating block (3) is arranged below the substrate (1), the upper part of the melting wire discharging assembly (5) is connected with the substrate (1), the middle part of the melting wire discharging assembly is connected with the radiating block (3), and the air cooling system (4) is arranged on the substrate (1) and used for cooling and radiating the radiating block (3) and the melting wire discharging assembly (5);

the melting wire-discharging assembly (5) comprises a throat pipe (501) and a heat insulation piece (506), the throat pipe (501) comprises a fixed section and a contraction section (L) with the suddenly reduced outer diameter, the heat dissipation block (3) comprises a bottom heat sink and a plurality of fins (301) integrally connected to the upper surface of the bottom heat sink, the fixed section of the throat pipe (501) is fixedly connected with the bottom heat sink of the heat dissipation block (3), the upper end of the fixed section penetrates through the bottom heat sink to be sleeved with the lower end of the heat insulation piece (506), the upper end of the heat insulation piece (506) is connected with the substrate (1), so that the heat insulation piece (506) is located in an air flow channel between the fins (301), and the contraction section (L) is located below the bottom;

the air cooling system (4) comprises an air flow channel, the air flow channel comprises an axial flow fan (404), a turbofan (401) and a turbofan air deflector (402) which are sequentially arranged, the fins (301) are arranged between the axial flow fan (404) and the turbofan (401), the air cooling system (4) further comprises an axial flow fan air deflector (405) and an angle adjusting plate (403), the axial flow fan (404) is installed on the substrate (1) through the angle adjusting plate (403), and the axial flow fan air deflector (405) is installed at the bottom of the axial flow fan (404), so that the axial flow fan (404) has an inclination angle relative to the front end face of the heat dissipation block (3) and partial cold air of the axial flow fan (404) is guided to the contraction section (L) of the throat pipe (501).

2. The 3D printer head of claim 1, wherein: the melting wire discharging assembly (5) further comprises a nozzle (502), a heat storage block (503), a heating rod (505) and a joint (507), the lower end of the throat pipe (501) is connected with the heat storage block (503), the nozzle (502) is installed below the heat storage block (503), the heating rod (505) is installed in the heat storage block (503), the joint (507) is installed on the upper end face of the heat insulation piece (506), the heat insulation piece (506) and the joint (507) are of tubular hollow structures, and the joint (507), the heat insulation piece (506), the throat pipe (501) and the nozzle (502) are sequentially and coaxially communicated to form a wire material circulation channel.

3. The 3D printer head of claim 2, wherein: the upper end of the nozzle (502) is provided with an inner hole matched with the lower end of the throat pipe (501), and when the nozzle (502) is screwed on the heat storage block (503) from bottom to top, the bottom surface of the inner hole of the nozzle (502) is tightly attached to the lower end surface of the throat pipe (501).

4. The 3D printer head of claim 2, wherein: the melting wire-discharging assembly (5) further comprises a temperature sensor (504) arranged in the heat storage block (503).

5. The 3D printer head of claim 1, wherein: the heat insulation piece (506) is made of polytetrafluoroethylene or polyether-ether-ketone.

6. The 3D printer head of claim 1, wherein: the turbofan air deflector (402) is used for guiding cold air of the turbofan (401) to the position below the nozzle (502).