CN115195119B

CN115195119B - 3D printer

Info

Publication number: CN115195119B
Application number: CN202210734124.7A
Authority: CN
Inventors: 杨德安
Original assignee: Xiamen Smart Industrial Design Co ltd
Current assignee: Xiamen Smart Industrial Design Co ltd
Priority date: 2022-06-27
Filing date: 2022-06-27
Publication date: 2024-10-29
Anticipated expiration: 2042-06-27
Also published as: CN115195119A

Abstract

The invention relates to the technical field of 3D printers, in particular to a 3D printer. The automatic feeding device comprises a machine body, wherein a printing platform is connected to one side wall of the machine body in a sliding manner along the vertical direction, an extrusion head is arranged right above the printing platform, a feeding unit is arranged in the machine body, and the bottom of the feeding unit is communicated with a hot melting unit; the hot melting unit comprises a hot melting cylinder; the utility model discloses a feeding unit, including feeding unit, first inner tube, second inner tube, hot-melt section of thick bamboo, feed head top intercommunication is in feeding unit bottom, be provided with first inner tube in the hot-melt section of thick bamboo, be equipped with the second inner tube in the first inner tube, the axis of first inner tube, second inner tube and hot-melt section of thick bamboo all coincides, hot-melt section of thick bamboo inner wall and first inner tube outer wall, and all be equipped with the clearance between first inner tube inner wall and the second inner tube outer wall. The invention improves the fluency of raw material wire transportation and improves the hot melting efficiency.

Description

3D printer

Technical Field

The invention belongs to the technical field of 3D printers, and particularly relates to a 3D printer.

Background

The raw materials used for the 3D printer generally include metal powder and engineering plastics, wherein the engineering plastics are widely used due to mature technology and low cost.

When the engineering plastic is used, the solid raw material wire is usually conveyed into a hot melting unit to be heated, so that the raw material wire becomes a viscous liquid, and then the viscous liquid is extruded onto a printing platform by an extrusion head. The existing hot melting units generally heat a single cavity, and then heat energy in the cavity is used for hot melting the raw material profile. This causes heat energy to act on the raw wire gradually from outside to inside, resulting in low heat melting speed and low heat melting efficiency.

Disclosure of Invention

The invention provides a 3D printer which aims at the problems and comprises a printer body, wherein a printing platform is connected to one side wall of the printer body in a sliding manner along the vertical direction, an extrusion head is arranged right above the printing platform, a feeding unit is arranged in the printer body, and the bottom of the feeding unit is communicated with a hot melting unit;

The hot melting unit comprises a hot melting cylinder; the top of the hot melting cylinder is communicated with a feeding head, the top of the feeding head is communicated with the bottom of the feeding unit, a first inner cylinder is arranged in the hot melting cylinder, a second inner cylinder is arranged in the first inner cylinder, the central axes of the first inner cylinder, the second inner cylinder and the hot melting cylinder are all coincident, and gaps are formed between the inner wall of the hot melting cylinder and the outer wall of the first inner cylinder and between the inner wall of the first inner cylinder and the outer wall of the second inner cylinder; the inner wall and the outer wall of the first inner cylinder and the second inner cylinder and the inner wall of the hot melting cylinder are uniformly distributed with a plurality of groups of polishing blocks, and the tops of the polishing blocks are provided with inclined planes; a hot melt air inlet is formed in the outer wall of the hot melt cylinder, and one end of the hot melt air inlet is communicated with a heat transfer rod; the other end of the heat transfer rod sequentially penetrates through the first inner cylinder and the second inner cylinder and is fixedly connected with the inner walls of the first inner cylinder and the second inner cylinder; the bottom of the hot melting cylinder is communicated with a discharge head, and the other end of the discharge head is communicated with the output end of the extrusion head.

Further, a double-shaft electric sliding table is arranged right above the printing platform, and the extrusion head is connected to the output end of the double-circumference electric sliding table in a sliding manner; a servo motor is arranged on one side wall of the machine body far away from the base, a bevel gear is connected to the output end of the servo motor in a transmission mode, and the other end of the bevel gear is connected with the power input part of the feeding unit in a transmission mode.

Furthermore, a hot melting heating device is arranged in the machine body, and the output end of the hot melting heating device is communicated with the feeding unit and the hot melting unit.

Further, the feeding unit comprises a preheating mechanism; the preheating mechanism comprises a preheating cylinder, the preheating cylinder is arranged at the top of the machine body, the bottom of the preheating cylinder extends to the machine body, a first channel is formed in the center of the preheating cylinder, a channel inner wall cavity is formed in the inner wall of the first channel, a preheating air inlet is formed in one side wall, far away from the first channel, of the channel inner wall cavity, and the other end of the preheating air inlet is communicated with the hot melting heating equipment through a pipeline.

Further, preheating ports are evenly distributed on one side wall, close to the first channel, of the inner wall cavity of the channel, and the other end of each preheating port is communicated with the first channel; the inner diameter of the preheating port, which is close to one end of the first channel, is smaller than that of the other end of the preheating port; the bottom of the preheating cylinder is rotationally connected with a first sealing bearing, and the bottom of the first sealing bearing is rotationally connected with a spiral wire feeding mechanism.

Further, the spiral wire feeding mechanism comprises a wire feeding cylinder, a second channel is formed in the center of the wire feeding cylinder, and the top of the second channel is communicated with the first channel through a first sealing bearing; the inner wall of the second channel is spirally provided with spiral raised strips, and a plurality of groups of anti-slip convex blocks are arranged on the spiral raised strips at equal intervals.

Further, a bevel gear is sleeved on the outer wall of the wire feeding cylinder and is in meshed connection with the bevel gear; and the bottom of the wire feeding cylinder is rotationally connected with a second sealing bearing.

Further, a plurality of groups of cutting blades are arranged in the feeding head at equal intervals, the blade tips of the cutting blades are positioned at the top of the feeding head, and a plurality of groups of auxiliary cutting blades are arranged on the two side walls of the cutting blades at equal intervals.

Further, the printing platform comprises a platform body; the platform body is connected to one side wall of the machine body, which is close to the extrusion head, in a sliding manner along the vertical direction, and is positioned right below the extrusion head; an air heater is fixedly arranged in the platform body, a heat conducting plate is arranged on the air heater, and the other side wall of the heat conducting plate is attached to the inner wall of the top of the platform body; a group of side plates are arranged at the top edges of the periphery of the platform body, and a plurality of groups of side plates are connected end to end in sequence; the inner cavity of the side plate is communicated with the output end of the air heater through a pipeline.

Further, a plurality of groups of first air outlets are arranged on a side wall of the side plate, which is close to the center line of the platform body, at equal intervals along the horizontal direction; the heights of the two ends of the first air outlet are the same; a plurality of groups of second air outlets are arranged right above each group of first air outlets at equal intervals along the vertical direction; the second air outlet is close to the inner cavity of the side plate is lower in height at one end than at the other end; and a plurality of groups of third air outlets are uniformly arranged under each group of first air outlets along the vertical direction at equal intervals, and the height of one end of each third air outlet close to the inner cavity of the side plate is higher than that of the other end of each third air outlet.

The beneficial effects of the invention are as follows:

1. Firstly, a plurality of groups of blanking blades which are arranged at equal intervals are utilized to cut the preheated raw material wire into a plurality of particles. And then, layering heating is carried out on a plurality of granular raw material wires by using the hot melting cylinder, the first inner cylinder and the second inner cylinder, so that the granular raw material wires are melted into sticky liquid. The contact area of the raw material wire and the hot melting mechanism is increased, so that the heating is more uniform, the occurrence of blockage at the joint of the feeding unit and the hot melting unit caused by too slow heating of the raw material wire is avoided, and the heating speed of the raw material wire is improved. And the hot melting efficiency is improved while the conveying smoothness of the raw material wires is improved.

2. A plurality of groups of auxiliary cutting blades are distributed on the two side walls of the cutting blade at equal intervals, and the cutting direction of the auxiliary cutting blades is perpendicular to the cutting direction of the cutting blade. When the raw material wire is cut by the cutting blade, fragments of the raw material wire slide from two sides and contact with the auxiliary cutting blade, and secondary cutting is performed from different angles, so that the volume of the raw material wire particles is further reduced. Not only improves the efficiency of the subsequent hot melting work, but also improves the cutting quality of the raw material wires, and avoids the raw material wires from being blocked in the gaps between two adjacent groups of blanking blades due to incomplete cutting.

3. The bevel gear drives the bevel gear to rotate, and then the bevel gear drives the wire feeding barrel to rotate, and because the spiral convex strips are spirally distributed on the inner wall of the second channel, when the wire feeding barrel rotates, a plurality of groups of anti-slip convex blocks which are uniformly arranged on the spiral convex strips can be utilized to simultaneously drive the raw material wires to move downwards from all directions. Not only make raw materials wire rod surface atress more even, can not appear in the past both sides set up the problem that the direction of delivery appears that the conveying roller brought. Meanwhile, the friction force and the stress direction between the wire rod and the surface of the raw wire rod are increased, the traditional slipping condition is avoided, and the smoothness of the conveying work of the raw wire rod is improved.

4. The hot air is generated through the operation of the air heater, and then the 3D model is heated and baked from the bottom and the periphery through the heat conducting plate, the first air outlet, the second air outlet and the third air outlet, so that the solidification function is realized. And the second air outlet above the first air outlet is higher than the other end at one end close to the center of the platform body, and the third air outlet below the first air outlet is lower than the other end at one end close to the center of the platform body, so that hot air is blown to the surface of the D model in a radial mode. The contact area between the hot air and the D model is increased, and the solidification effect is improved while the fixing function is realized.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions of the prior art, the following description will briefly explain the drawings used in the embodiments or the description of the prior art, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 shows a schematic configuration of a 3D printer according to an embodiment of the present invention;

FIG. 2 shows a right side cross-sectional schematic view of a 3D printer according to an embodiment of the invention;

fig. 3 shows a schematic structural view of a feeding unit according to an embodiment of the present invention;

FIG. 4 shows a schematic cross-sectional view of a preheating mechanism according to an embodiment of the present invention;

FIG. 5 shows a schematic cross-sectional view of a screw feed mechanism according to an embodiment of the invention;

FIG. 6 shows a schematic cross-sectional view of a thermal fuse unit in accordance with an embodiment of the present invention;

FIG. 7 illustrates a schematic diagram of the connection of a hot melt cartridge, a first inner cartridge, and a second inner cartridge in accordance with an embodiment of the present invention;

fig. 8 shows a schematic structural view of a blanking blade according to an embodiment of the present invention;

fig. 9 shows a schematic structural view of a printing platform according to an embodiment of the present invention;

Fig. 10 shows a schematic cross-sectional view of a printing platform according to an embodiment of the invention.

In the figure: 100. a body; 110. a base; 120. a platform lifting mechanism; 130. a hot melt heating device; 140. a servo motor; 150. bevel gears; 200. double-shaft electric slipway; 300. an extrusion head; 400. a feeding unit; 410. a preheating mechanism; 411. a preheating cylinder; 412. a first channel; 413. a channel inner wall cavity; 414. a preheating port; 415. preheating an air inlet; 420. a spiral wire feeding mechanism; 421. a wire feeding cylinder; 422. a second channel; 423. spiral raised strips; 424. an anti-slip bump; 430. a first sealed bearing; 440. bevel gear; 450. a second sealed bearing; 500. a hot melting unit; 510. a hot melt cylinder; 511. a hot melt air inlet; 512. a heat transfer rod; 520. a feed block; 530. a blanking blade; 531. an auxiliary cutting blade; 540. a first inner cylinder; 550. a second inner cylinder; 560. polishing the block; 570. a discharge head; 600. a printing platform; 610. a platform body; 620. an air heater; 630. a heat conductive plate; 640. a side plate; 650. a first air outlet; 660. a second air outlet; 670. and a third air outlet.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

An embodiment of the present invention provides a 3D printer including a body 100. As shown in fig. 1 and 2, a base 110 is fixedly installed at the bottom edge of a side wall of the machine body 100, and a circuit control system is disposed in the base 110.

The base 110 is provided with a double-shaft electric sliding table 200 directly above, and an extrusion head 300 is installed on the output end of the double-shaft electric sliding table 200.

The top of the machine body 100 is provided with a feeding unit 400, the bottom of the feeding unit 400 extends into the machine body 100 and is communicated with a hot melting unit 500, and the output end of the hot melting unit 500 is communicated with the extrusion head 300. The feeding unit 400 is used for continuously pushing the raw material wire into the hot melting unit 500, and the hot melting unit 500 is used for high-temperature melting the raw material wire in a solid state into a viscous liquid.

A servo motor 140 is mounted on a side wall of the machine body 100 far away from the base 110, a bevel gear 150 is connected to an output end of the servo motor 140 in a transmission manner, and the other end of the bevel gear 150 is connected with a power input part of the feeding unit 400 in a transmission manner.

The hot melting heating device 130 is arranged in the machine body 100, and the output end of the hot melting heating device 130 is communicated with the feeding unit 400 and the hot melting unit 500. The hot melt heating apparatus 130 is used to provide heat energy for preheating the raw wire rods and for hot melting.

A platform lifting mechanism 120 is installed on a side wall of the machine body 100, which is close to the base 110, in a vertical direction, a printing platform 600 is installed on an output end of the platform lifting mechanism 120, and the printing platform 600 is located between the base 110 and the extrusion head 300.

The feeding unit 400 includes a preheating mechanism 410. As shown in fig. 3,4 and 5, the preheating mechanism 410 includes a preheating barrel 411, the preheating barrel 411 is mounted at the top of the machine body 100, the bottom of the preheating barrel 411 extends to the machine body 100, a first channel 412 is formed in the center of the preheating barrel 411, a channel inner wall cavity 413 is formed in the inner wall of the first channel 412, a preheating air inlet 415 is formed in a side wall of the channel inner wall cavity 413 far from the first channel 412, and the other end of the preheating air inlet 415 is communicated with the hot melting heating device 130 through a pipeline. The inner wall 413 of the channel is provided with preheating ports 414 on a side wall near the first channel 412, and the other end of the preheating ports 414 is communicated with the first channel 412. The preheating port 414 has a smaller inner diameter near one end of the first passage 412 than the other end. The bottom of the preheating barrel 411 is rotatably connected with a first sealing bearing 430, and the bottom of the first sealing bearing 430 is rotatably connected with a spiral wire feeding mechanism 420.

Illustratively, the spiral feeding mechanism 420 includes a feeding cylinder 421, a second channel 422 is formed in the center of the feeding cylinder 421, and the top of the second channel 422 is communicated with the first channel 412 through a first sealing bearing 430. Spiral raised strips 423 are spirally arranged on the inner wall of the second channel 422, and a plurality of groups of anti-slip bumps 424 are arranged on the spiral raised strips 423 at equal intervals. The outer wall of the wire feeding cylinder 421 is sleeved with a bevel gear 440, and the bevel gear 440 is meshed with the bevel gear 150. The bottom of the wire feeding cylinder 421 is rotatably connected with a second sealing bearing 450.

First, one end of the raw material wire is inserted into the first channel 412 and sequentially penetrates through the first sealing bearing 430 and the second channel 422, so that each group of anti-slip bumps 424 can be attached to the raw material wire from all directions. The hot melt heating apparatus 130 is then activated, with which hot gas is supplied into the cavity of the hot melt unit 500 and the channel inner wall cavity 413, the temperature in the cavity of the hot melt unit 500 is raised to between 400 and 450 c, and the temperature in the channel inner wall cavity 413 is raised to between 70 and 110 c. Then, the servo motor 140 is started, the bevel gear 150 is driven to rotate by the servo motor 140, and the wire feeding barrel 421 is driven to rotate by utilizing the meshing connection relationship of the bevel gear 150 and the bevel gear 440. Because the spiral raised strips 423 are spirally distributed on the inner wall of the second channel 422, when the wire feeding barrel 421 rotates, each group of anti-slip lugs 424 can be utilized to drive the raw material wires to move downwards, so that the feeding purpose is realized.

The bevel gear 150 drives the bevel gear 440 to rotate, and then the bevel gear 440 drives the wire feeding barrel 421 to rotate, and because the spiral raised strips 423 are spirally distributed on the inner wall of the second channel 422, when the wire feeding barrel 421 rotates, a plurality of groups of anti-slip lugs 424 which are uniformly arranged on the spiral raised strips 423 can be utilized to simultaneously drive the raw material wires to move downwards from all directions. Not only make raw materials wire rod surface atress more even, can not appear in the past both sides set up the problem that the direction of delivery appears that the conveying roller brought. Meanwhile, the friction force and the stress direction between the wire rod and the surface of the raw wire rod are increased, the traditional slipping condition is avoided, and the smoothness of the conveying work of the raw wire rod is improved.

After entering the inner wall cavity 413 of the channel, the hot air enters the first channel 412 through the preheating ports 414 uniformly distributed on the inner wall of the first channel 412, and then acts on the raw material wire. And because the inner diameter of the preheating opening 414 near one end of the first channel 412 is smaller than that of the other end, when the hot air passes through the preheating opening 414, the pressure intensity is increased, the flow speed is increased, the contact force with the raw material wire is also increased, and the preheating effect of the raw material wire is improved.

The hot melt unit 500 includes a hot melt cartridge 510. As shown in fig. 6, 7 and 8, the top of the hot-melting cylinder 510 is connected with a feeding head 520, the central axis of the feeding head 520 coincides with the central axis of the hot-melting cylinder 510, and the top of the feeding head 520 is rotatably connected to the bottom of the second sealing bearing 450. And the feed head 520 communicates with the second passage 422 through a second sealed bearing 450. A plurality of sets of cutting blades 530 are arranged in the feeding head 520 at equal intervals, the cutting points of the cutting blades 530 are positioned at the top of the feeding head, and a plurality of sets of auxiliary cutting blades 531 are arranged on two side walls of the cutting blades 530 at equal intervals. The first inner cylinder 540 is disposed in the hot-melting cylinder 510, the central axis of the first inner cylinder 540 coincides with the central axis of the hot-melting cylinder 510, and a gap is disposed between the outer wall of the first inner cylinder 540 and the inner wall of the hot-melting cylinder 510. The first inner cylinder 540 is provided with a second inner cylinder 550, a central axis of the second inner cylinder 550 coincides with a central axis of the first inner cylinder 540, and a gap is provided between an outer wall of the second inner cylinder 550 and an inner wall of the first inner cylinder 540. The inner and outer walls of the first inner cylinder 540 and the second inner cylinder 550 and the inner wall of the hot-melting cylinder 510 are uniformly distributed with a plurality of groups of polishing blocks 560, and the top of each polishing block 560 is provided with an inclined plane. The outer wall of the hot-melt cylinder 510 is provided with a hot-melt air inlet 511, one end of the hot-melt air inlet 511 is communicated with the hot-melt heating device 130 through a pipeline, and the other end is communicated with a heat transfer rod 512. The other end of the heat transfer rod 512 sequentially penetrates through the first inner cylinder 540 and the second inner cylinder 550, and is fixedly connected with the inner walls of the first inner cylinder 540 and the second inner cylinder 550. The heat transfer rod 512 is made of copper, but is not limited to copper. The bottom of the hot melting cylinder 510 is communicated with a discharge head 570, and the other end of the discharge head 570 is communicated with the input end of the extrusion head 300.

Preferably, the hot melting unit 500 further includes, but is not limited to, a third inner cylinder and a fourth inner cylinder, wherein the third inner cylinder is located in the second inner cylinder 550, a central axis of the third inner cylinder coincides with a central axis of the second inner cylinder 550, and a gap is provided between an outer wall of the third inner cylinder and an inner wall of the second inner cylinder 550. The fourth inner cylinder is positioned in the third inner cylinder, and the central axis of the fourth inner cylinder coincides with the central axis of the third inner cylinder. A gap is arranged between the outer wall of the fourth inner cylinder and the inner wall of the third inner cylinder.

The preheated raw wire is fed into the feed head 520 by the screw feeding mechanism 420, and the preheated raw wire is softened due to the continuity of the feeding operation of the screw feeding mechanism 420, so that the raw wire is cut into a plurality of particles after contacting each group of cutting blades 530. Then falls downwards under the action of gravity and randomly falls into the gaps between the hot melting cylinder 510 and the first inner cylinder 540 and between the first inner cylinder 540 and the second inner cylinder 550 or into the cavity of the second inner cylinder 550, and utilizes the heat transfer rod 512 to uniformly transfer heat energy to the inner wall of the hot melting cylinder 510 and the first inner cylinder 540 and the second inner cylinder 550. The purpose of hot melting can be achieved no matter where the granular raw material wire falls.

The preheated raw wire is first cut into a plurality of pellets using a plurality of sets of cutter blades 530 arranged at equal intervals. Then, the granular raw material wires are layered and heated by the hot melting cylinder 510, the first inner cylinder 540 and the second inner cylinder 550, so that the raw material wires are melted into viscous liquid. The contact area of the raw material wire and the hot melting mechanism is increased, so that the raw material wire is heated more uniformly, the situation that the joint of the feeding unit 400 and the hot melting unit 500 is blocked due to too slow heating of the raw material wire is avoided, and the heating speed of the raw material wire is improved. And the hot melting efficiency is improved while the conveying smoothness of the raw material wires is improved.

A plurality of auxiliary cutting blades 531 are equally spaced on both sidewalls of the cutter blade 530, and the cutting direction of the auxiliary cutting blades 531 is perpendicular to the cutting direction of the cutter blade 530. When the raw wire is cut by the cutter blade 530, its chips slide off from both sides and contact the auxiliary cutter blade 531, and the secondary cutting is performed from different angles, further reducing the volume of the raw wire particles. Not only improves the efficiency of the subsequent hot melting work, but also improves the cutting quality of the raw material wires, and avoids the raw material wires from being blocked in gaps between two adjacent groups of blanking blades 530 due to incomplete cutting.

The print platform 600 includes a platform body 610. Illustratively, as shown in fig. 9 and 10, the platform body 610 is fixedly mounted on the output end of the platform lift mechanism 120, and the platform body 610 is positioned between the extrusion head 300 and the base 110. An air heater 620 is fixedly installed in the platform body 610, a heat conducting plate 630 is installed on the air heater 620, and the other side wall of the heat conducting plate 630 is attached to the inner wall of the top of the platform body 610. A set of side plates 640 are arranged at the top edges of the periphery of the platform body 610, and a plurality of sets of side plates 640 are connected end to end in sequence. The inner cavity of the side plate 640 is communicated with the output end of the air heater 620 through a pipeline. A plurality of groups of first air outlets 650 are arranged on a side wall of the side plate 640 near the center line of the platform body 610 at equal intervals along the horizontal direction. The heights of the two ends of the first air outlet 650 are the same. A plurality of sets of second air outlets 660 are arranged right above each set of the first air outlets 650 at equal intervals along the vertical direction. The second air outlet 660 is lower in height near one end of the inner cavity of the side plate 640 than the other end. And a plurality of groups of third air outlets 670 are arranged under each group of first air outlets 650 at equal intervals along the vertical direction, and the height of one end of each third air outlet 670 close to the inner cavity of the side plate 640 is higher than that of the other end. The heat conducting plate 630 is made of copper, but not limited to copper.

The raw material wires after the hot melting are in a viscous liquid state and then are conveyed into the extrusion head 300 through a pipeline, the double-shaft electric sliding table 200 is utilized to drive the extrusion head 300 to simultaneously realize movement in two directions, and the platform lifting mechanism 120 is utilized to drive the platform body 610 to vertically lift. So that extrusion head 300 can print any desired 3D model on platform body 610.

And hot air is generated by the operation of the hot air blower 620 while 3D printing is performed, the heat conducting plate 630 is heated to 60-75 ℃, and the 3D model is heated and baked from the bottom by the heat conducting plate 630, so that the curing effect is realized. Then, the air heater 620 then delivers the remaining hot air into the cavities of the sets of side plates 640, and then the sets of first air outlets 650, second air outlets 660 and third air outlets 670 deliver the hot air onto the side walls of the 3D model. The second air outlet 660 above the first air outlet 650 has a higher height at one end near the center of the platform body 610 than the other end, and the third air outlet 670 below the first air outlet 650 has a lower height at one end near the center of the platform body 610 than the other end, so that hot air is blown to the 3D model surface in a radial shape. The contact area of hot air and the 3D model is increased, and the solidification effect is improved while the fixing function is realized.

Although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A 3D printer, characterized in that: the automatic feeding device comprises a machine body (100), wherein a printing platform (600) is connected to one side wall of the machine body (100) in a sliding manner along the vertical direction, an extrusion head (300) is arranged right above the printing platform (600), a feeding unit (400) is arranged in the machine body (100), and a hot melting unit (500) is communicated with the bottom of the feeding unit (400);

The hot melting unit (500) comprises a hot melting cylinder (510); the hot melting device is characterized in that a feeding head (520) is communicated with the top of the hot melting cylinder (510), the top of the feeding head (520) is communicated with the bottom of the feeding unit (400), a first inner cylinder (540) is arranged in the hot melting cylinder (510), a second inner cylinder (550) is arranged in the first inner cylinder (540), central axes of the first inner cylinder (540), the second inner cylinder (550) and the hot melting cylinder (510) are all overlapped, and gaps are formed between the inner wall of the hot melting cylinder (510) and the outer wall of the first inner cylinder (540) and between the inner wall of the first inner cylinder (540) and the outer wall of the second inner cylinder (550); the inner and outer walls of the first inner cylinder (540) and the second inner cylinder (550) and the inner wall of the hot melting cylinder (510) are uniformly distributed with a plurality of groups of polishing blocks (560), and the tops of the polishing blocks (560) are provided with inclined planes; a hot melt air inlet (511) is formed in the outer wall of the hot melt cylinder (510), and one end of the hot melt air inlet (511) is communicated with a heat transfer rod (512); the other end of the heat transfer rod (512) sequentially penetrates through the first inner cylinder (540) and the second inner cylinder (550) and is fixedly connected with the inner walls of the first inner cylinder (540) and the second inner cylinder (550); the bottom of the hot melting cylinder (510) is communicated with a discharge head (570), and the other end of the discharge head (570) is communicated with the output end of the extrusion head (300);

The feeding unit (400) comprises a preheating mechanism (410); the preheating mechanism (410) comprises a preheating cylinder (411), the preheating cylinder (411) is arranged at the top of the machine body (100), the bottom of the preheating cylinder (411) extends to the machine body (100), a first channel (412) is formed in the center of the preheating cylinder (411), a channel inner wall cavity (413) is formed in the inner wall of the first channel (412), and a preheating air inlet (415) is formed in one side wall, far away from the first channel (412), of the channel inner wall cavity (413);

the bottom of the preheating cylinder (411) is rotationally connected with a first sealing bearing (430), and the bottom of the first sealing bearing (430) is rotationally connected with a spiral wire feeding mechanism (420); the spiral wire feeding mechanism (420) comprises a wire feeding barrel (421), a second channel (422) is formed in the center of the wire feeding barrel (421), and spiral raised strips (423) are spirally arranged on the inner wall of the second channel (422); a plurality of groups of anti-slip convex blocks (424) are arranged on the spiral convex strips (423) at equal intervals;

a plurality of groups of cutting blades (530) are arranged in the feeding head (520) at equal intervals, the blades of the cutting blades (530) are positioned at the top of the feeding head, and a plurality of groups of auxiliary cutting blades (531) are arranged on two side walls of the cutting blades (530) at equal intervals;

The printing platform (600) comprises a platform body (610); the platform body (610) is connected to one side wall of the machine body (100) close to the extrusion head (300) in a sliding manner along the vertical direction, and the platform body (610) is positioned right below the extrusion head (300); an air heater (620) is fixedly arranged in the platform body (610), a heat conducting plate (630) is arranged on the air heater (620), and the other side wall of the heat conducting plate (630) is attached to the inner wall of the top of the platform body (610); a group of side plates (640) are arranged at the top edges of the periphery of the platform body (610), and a plurality of groups of side plates (640) are connected end to end in sequence; the inner cavity of the side plate (640) is communicated with the output end of the air heater (620) through a pipeline;

A plurality of groups of first air outlets (650) are arranged on one side wall of the side plate (640) close to the center line of the platform body (610) at equal intervals along the horizontal direction; the heights of the two ends of the first air outlet (650) are the same; a plurality of groups of second air outlets (660) are arranged right above each group of the first air outlets (650) at equal intervals along the vertical direction; the height of one end of the second air outlet (660) close to the inner cavity of the side plate (640) is lower than that of the other end, and the heights are the same in the follow-up process; and a plurality of groups of third air outlets (670) are uniformly arranged under each group of first air outlets (650) along the vertical direction at equal intervals, and the height of one end of each third air outlet (670) close to the inner cavity of the side plate (640) is higher than that of the other end.

2. A 3D printer according to claim 1, wherein: a double-shaft electric sliding table (200) is arranged right above the printing platform (600), and the extrusion head (300) is connected to the output end of the double-shaft electric sliding table (200) in a sliding manner; a servo motor (140) is arranged on a side wall, far away from the base (110), of the machine body (100), a bevel gear (150) is connected to the output end of the servo motor (140) in a transmission mode, and the other end of the bevel gear (150) is connected with a power input part of the feeding unit (400) in a transmission mode.

3. A 3D printer according to claim 2, wherein: the hot melting machine is characterized in that a hot melting heating device (130) is arranged in the machine body (100), and the output end of the hot melting heating device (130) is communicated with the feeding unit (400) and the hot melting unit (500).

4. A 3D printer according to claim 2, wherein: the preheating air inlet (415) is far away from the inner wall cavity (413) of the channel and is communicated with the hot melting heating equipment (130) through a pipeline.

5. A 3D printer according to claim 4, wherein: a preheating opening (414) is evenly distributed on one side wall of the channel inner wall cavity (413) close to the first channel (412), and the other end of the preheating opening (414) is communicated with the first channel (412); the preheating port (414) has an inner diameter near one end of the first passage (412) smaller than an inner diameter at the other end.

6. A 3D printer according to claim 5, wherein: the top of the second channel (422) is communicated with the first channel (412) through a first sealing bearing (430).

7. A 3D printer according to claim 6, wherein: a bevel gear (440) is sleeved on the outer wall of the wire feeding cylinder (421), and the bevel gear (440) is meshed with the bevel gear (150); the bottom of the wire feeding cylinder (421) is rotatably connected with a second sealing bearing (450).