CN213166888U

CN213166888U - Multi-station hot melt extrusion 3D printing nozzle

Info

Publication number: CN213166888U
Application number: CN202021345009.3U
Authority: CN
Inventors: 刘寅初; 万晨浩; 许晓东; 冯辰
Original assignee: Yangzhou Polytechnic Institute
Current assignee: Yangzhou Polytechnic Institute
Priority date: 2020-07-10
Filing date: 2020-07-10
Publication date: 2021-05-11
Anticipated expiration: 2030-07-10

Abstract

A multi-station hot melt extrusion 3D printing nozzle comprises a charging barrel, a stirring paddle, a piston, an air cylinder and a servo motor, wherein a heating barrel is arranged outside the charging barrel; the charging barrel is of a structure with a sealed bottom and an open top, the center of the bottom of the charging barrel is provided with a discharge hole connected with the needle head, and the cross section of the inner cavity of the charging barrel is in a circular segment shape; the stirring paddle is driven by a servo motor, the piston is in a circular segment shape matched with the inner cavity of the charging barrel, the piston is in threaded connection with the stirring paddle, and the piston is provided with a limiting hole matched with a piston rod of the air cylinder; the servo motor drives the stirring paddle to rotate, so that the materials are stirred, and meanwhile, the piston rotates along with the stirring paddle; a piston rod of the air cylinder extends into a limiting hole of the piston to limit circumferential movement of the piston, at the moment, the servo motor drives the stirring paddle to rotate, and the piston moves downwards along the stirring paddle to realize stirring and extrusion of materials. Adopt the utility model discloses a shower nozzle, the linking of its technology link all can be gone on under high temperature environment, and it is very convenient to implement, has wide market space.

Description

Multi-station hot melt extrusion 3D printing nozzle

Technical Field

The utility model relates to a 3D prints the shower nozzle, specifically is a multistation heat melts extrudes 3D and prints the shower nozzle.

Background

The core of tissue engineering is to establish a three-dimensional space structure composed of cells and biological materials and form a vital living tissue, and a three-dimensional scaffold built by the biological materials is gradually degraded while functional cells in the tissue proliferate and divide, so that the damaged tissue is reconstructed in shape, function and structure and a permanent organ substitute is formed.

In the preparation process of the tissue engineering scaffold, a fused deposition type 3D printing technology is an effective technical means, the raw material is usually granular material or linear material, when the tissue engineering scaffold is used, the wire is sent into a heating nozzle of a printer through a feeding device, the material is fused into liquid through heating in a nozzle, the nozzle is controlled to move according to a set route through a servo driving system, the liquid material is deposited on a forming platform according to a certain rule, and the material is recovered into solid after being cooled. In the field of tissue engineering scaffolds, hot-melt molding 3D printing equipment is generally used for human tissues with high hardness, such as teeth, bones and the like, and the used materials are mostly biological consumables with high melting points (40-300 ℃).

At present, in the process of preparing a tissue scaffold, the consumable materials commonly used by fused deposition type 3D printing equipment include PLA (polylactic acid), PVA (polyvinyl alcohol), PHA (polycarboxyl fatty acid ester) and the like, and the consumable materials generally have good mechanical properties and thermal stability, have a high melting point, and are colloid materials capable of being extruded and molded at a certain temperature (80-120 ℃). In the research of biological scaffolds, some additives, such as oxidized nanocellulose, etc., are usually added to improve the biocompatibility of the material.

The process of preparing the composite material usually comprises the process links of heating and melting, adding additives, stirring and the like. Because the materials often have extremely high temperature-sensitive performance, the connection of the process links needs to be carried out in a high-temperature environment, and certain difficulty exists in specific implementation.

SUMMERY OF THE UTILITY MODEL

The utility model aims at the not enough of above-mentioned prior art, provide a multistation heat melts and extrudes 3D and prints shower nozzle.

The technical scheme of the utility model as follows:

the utility model aims at providing a multi-station hot melt extrusion 3D printing nozzle, which is characterized by comprising a charging barrel, a stirring paddle, a piston, a cylinder and a servo motor, wherein a heating barrel is arranged outside the charging barrel; the charging barrel is of a structure with a sealed bottom and an open top, the center of the bottom of the charging barrel is provided with a discharge hole connected with the needle head, and the cross section of the inner cavity of the charging barrel is in a circular segment shape; the stirring paddle is driven by the servo motor and extends into the charging barrel through the piston; the piston is in a segmental shape matched with the inner cavity of the charging barrel, is in threaded connection with the stirring paddle and is provided with a limiting hole matched with a piston rod of the air cylinder; the servo motor drives the stirring paddle to rotate, so that the materials are stirred, and meanwhile, the piston is positioned above the charging barrel and rotates along with the stirring paddle; a piston rod of the air cylinder extends into a limiting hole of the piston to limit the circumferential movement of the piston, at the moment, the servo motor drives the stirring paddle to rotate, and the piston moves downwards along the stirring paddle and enters the charging barrel; after the piston enters the charging barrel, the round structure of the inner cavity of the charging barrel restrains the piston, so that the piston continues to move downwards, and the stirring and extrusion of materials are realized.

Furthermore, a magnetic sheet is arranged at the bottom of the limiting hole, and one side of the magnetic sheet is hinged with the bottom of the limiting hole; the cylinder piston rod is internally provided with a material injection cavity, the top of the material injection cavity is provided with a material injection port, and the bottom of the material injection cavity is provided with a material discharge port; a piston rod of the air cylinder moves downwards to jack the magnetic sheet at the position of the limit hole, and materials are injected into the charging barrel through a material injection cavity of the piston rod; the piston rod of the cylinder moves upwards, and the magnetic sheet closes the limiting hole under the action of magnetic force.

Further, be equipped with the heating chamber of placing the feed cylinder in the heating bucket, the feed cylinder lateral wall is equipped with two bosss, the relative both sides in chamber wall in heating chamber are equipped with the bar groove respectively, the bar groove is arranged along the vertical upwards of heating chamber bottom, and its top has 1/4 arc groove along heating chamber circumference extension, corresponds two bosss and two bar grooves of feed cylinder, makes the feed cylinder get into the heating chamber from the bottom, and rotatory feed cylinder after the boss reachs bar groove top makes two bosss slide in the 1/4 arc groove that corresponds, fixes a position the feed cylinder.

Furthermore, an upper cover is arranged at the top of the heating barrel, a rack is arranged in the middle of the upper cover, and the air cylinder and the servo motor are installed at the rack.

Furthermore, the stirring device is characterized in that the end part of an output shaft of the servo motor is provided with a concave clamping jaw, and the top end of the stirring paddle is provided with a convex block matched with the stirring paddle.

Furthermore, the middle part of the stirring paddle is provided with an external thread to be in threaded fit with the central hole of the piston.

The utility model provides a multistation hot melt extrusion 3D prints shower nozzle, includes following operating condition:

1) at rest state

When the stirring paddle is in the initial position, the stirring paddle is positioned in the charging barrel, and the piston rod of the air cylinder is positioned above the piston and is not contacted with the piston; the piston is positioned above the charging barrel, and a gap is reserved between the lower surface of the piston and the top of the charging barrel;

2) stirring state

The servo motor drives the stirring paddle to rotate, so that the materials in the charging barrel are stirred, at the moment, the piston synchronously rotates along with the stirring paddle, and the position of the piston in the vertical direction is not changed;

3) state of material injection

The servo motor is driven, and the stirring paddle rotates to enable the limiting hole of the piston to be located right below the piston rod of the air cylinder;

the piston rod of the cylinder moves downwards, the lower end of the piston rod props up the magnetic sheet at the position of the position limiting hole, and the magnetic sheet extends into the charging barrel from the position limiting hole; the injection port of the cylinder piston rod is externally connected with an electromagnetic valve, and materials enter the charging barrel through the injection port, the injection cavity and the discharge port of the cylinder piston rod;

after the material injection is finished, the piston rod of the air cylinder moves upwards to leave the piston, and the magnetic sheet closes the limiting hole under the action of magnetic force;

4) stirring/extruding state

The piston rod of the cylinder moves downwards, and the lower end of the piston rod of the cylinder is in contact with the limiting hole of the piston to limit the circumferential rotation of the piston;

the servo motor drives the stirring paddle to stir the materials, and at the moment, the piston is constrained by a piston rod of the air cylinder, cannot rotate synchronously and moves downwards along the stirring paddle to enter the charging barrel;

after the material enters the material barrel, the piston is not restrained by the piston rod of the air cylinder any more, but can be restrained by the round structure of the inner cavity of the material barrel, still cannot rotate, and only can move downwards continuously to extrude the material, so that the material is extruded from the discharge hole at the bottom of the material barrel.

The utility model has the advantages of simple and reasonable structure, the manufacturing is easy, and atmospheric pressure through controlling among servo motor rotation and the cylinder changes, adjusts the operating condition of stirring rake, piston and magnetic sheet for 4 kinds of operating condition are freely switched to the shower nozzle: static state, stirring state, material injection state, stirring/extruding state. Therefore, adopt the utility model discloses a shower nozzle, the linking of its technology link all can be gone on under high temperature environment, and it is very convenient to implement, has wide market space.

Drawings

FIG. 1 is a schematic view of the internal assembly of the sprinkler head of the present invention;

FIG. 2 is a schematic view of the external structure of the sprinkler head of the present invention;

FIG. 3 is an exploded view of the sprinkler head of the present invention;

FIG. 4 is a schematic structural view of a heating barrel according to the present invention;

FIG. 5 is a cross-sectional view of FIG. 4;

FIG. 6 is a schematic structural view of a stirring paddle according to the present invention;

FIG. 7 is a schematic structural view of the cartridge of the present invention;

fig. 8 is a schematic structural view of the cylinder of the present invention;

fig. 9 is a schematic structural view of a piston rod of a cylinder according to the present invention;

FIG. 10 is a cross-sectional view of FIG. 9;

fig. 11 is a schematic structural view of the upper cover of the present invention;

fig. 12 is a schematic mechanism diagram (including a servo motor) of the middle frame of the present invention;

in the figure: the device comprises a charging barrel 1, a stirring paddle 2, a piston 3, a cylinder 4, a servo motor 5, a discharge hole 6, a material injection cavity 9, a material injection port 10, a discharge port 11, a heating barrel 12, a boss 13, an 1/4 arc-shaped groove 14, an upper cover 15, a frame 16, a concave clamping jaw 17, a convex block 18, a cylinder piston rod 19, a through hole 20 of the annular boss and a strip-shaped groove 21.

Detailed Description

As shown in the figure, the multi-station hot melt extrusion 3D printing nozzle comprises a material cylinder 1, a stirring paddle 2, a piston 3, a cylinder 4 and a servo motor 5, wherein the material cylinder is of a structure with a sealed bottom and an open top, a discharge hole 6 connected with a needle head is formed in the center of the bottom of the material cylinder, and the cross section of an inner cavity of the material cylinder is in a circular segment shape; the stirring paddle is driven by the servo motor and extends into the charging barrel through the piston; the piston is in a circular segment shape matched with the inner cavity of the charging barrel, the piston is in threaded connection with the stirring paddle (the middle part of the stirring paddle is provided with an external thread to be in threaded fit with the central hole of the piston), and the piston is provided with a limiting hole (the limiting hole is eccentrically arranged) matched with the piston rod of the air cylinder; the servo motor drives the stirring paddle to rotate, so that the materials are stirred, and meanwhile, the piston is positioned above the charging barrel and rotates along with the stirring paddle; the piston rod 19 of the air cylinder extends into the limiting hole of the piston to limit the circumferential movement of the piston, at the moment, the servo motor drives the stirring paddle to rotate, and the piston moves downwards along the stirring paddle to realize the stirring and extrusion of materials.

Specifically, a magnetic sheet is arranged at the bottom of the limiting hole, and one side of the magnetic sheet is hinged with the bottom of the limiting hole; a material injection cavity 9 is arranged inside the piston rod of the cylinder, the top of the material injection cavity is provided with a material injection port 10, and the bottom of the material injection cavity is provided with a material discharge port 11; a piston rod of the air cylinder moves downwards to jack the magnetic sheet at the position of the limit hole, and materials are injected into the charging barrel through a material injection cavity of the piston rod; the piston rod of the cylinder moves upwards, and the magnetic sheet closes the limiting hole under the action of magnetic force.

It is specific, the feed cylinder has heating barrel 12 outward, is equipped with the heating chamber of placing the feed cylinder in the heating barrel, the feed cylinder lateral wall is equipped with two bosss 13, the relative both sides in chamber wall in heating chamber are equipped with strip groove 21 respectively, the strip groove is along the vertical upwards arranging of heating chamber bottom, and its top has 1/4 arc groove 14 along heating chamber circumference extension, corresponds two bosss and two strip grooves of feed cylinder, makes the feed cylinder get into the heating chamber from the bottom, and rotatory feed cylinder behind the strip groove top is reachd to the boss, makes two bosss slide in the 1/4 arc groove that corresponds, fixes a position the feed cylinder.

Specifically, the top of the heating barrel is provided with an upper cover 15, the middle of the upper cover is provided with a rack 16, and the air cylinder and the servo motor are arranged at the rack. The output shaft end of the servo motor is provided with a concave clamping jaw 17, and the top end of the stirring paddle is provided with a convex block 18 matched with the stirring paddle.

The utility model discloses a shower nozzle includes 4 operating condition: the device comprises a stand, a stirring state, a material injection state and a stirring/extruding state, wherein different working states are adjusted by the rotation of a servo motor in the stand and the change of air pressure in an air cylinder. Specifically, the method comprises the following steps:

1) a static state:

before the device is used, granular PLA or other similar materials are filled into a barrel, a discharge hole is arranged below the barrel and is connected with a conical or needle-shaped needle head, and the inside of the barrel is a cylinder with steps (namely the cross section of an inner cavity of the barrel is in a circular segment shape). The feed cylinder outer wall is equipped with 2 bosss for carry out circumferencial direction's location in the heating barrel, and the relative both sides in heating chamber of heating barrel are equipped with bar groove 21 along length direction, and bar groove top has 1/4 circular arc groove 14 along heating chamber circumference extension.

During the installation, the feed cylinder gets into the heating intracavity from heating barrel head portion, and two bosss 13 of feed cylinder correspond with two bar groove 21 positions in heating chamber respectively, so that the feed cylinder gets into the heating chamber smoothly, after the boss reachd bar groove top, with the feed cylinder rotation 90, make two bosss 13 of feed cylinder slide into corresponding 1/4 arc-shaped groove 14 respectively, in order to fix a position the feed cylinder (start servo motor, the stirring rake is rotatory, the boss is located 1/4 arc-shaped inslot, 1/4 arc-shaped groove end structure can carry out circumference spacing to the feed cylinder, prevent that the feed cylinder from taking place to rotate).

After the charging barrel is arranged in the heating barrel, other parts such as a stirring paddle, a piston and the like are respectively arranged above the charging barrel. Under the initial position, the stirring rake is located the feed cylinder below discharge opening directly over, and the clearance is about 5mm, and the piston is installed in the feed cylinder top, and the piston lower surface is a little higher than feed cylinder upper surface position.

2) Stirring:

the end part of an output shaft of the servo motor is provided with a concave clamping jaw for matching with a convex block at the top of the stirring paddle, and the part of the middle section of the stirring paddle, which is connected with the piston, is provided with an external thread line for matching with an internal thread line on the central hole of the piston. Servo motor rotates and drives the stirring rake and rotates, can realize stirring the interior material of feed cylinder, and simultaneously, the piston is followed the stirring rake and is synchronous rotation, and the position of piston on the vertical direction can not change.

3) And (3) material injection state:

when the material station is annotated in the switching, through the change of atmospheric pressure in the cylinder, promote cylinder piston rod downwards, make its lower extreme stretch into the feed cylinder from the spacing hole of piston in, the magnetic sheet is installed to the spacing hole below of piston, and its area is greater than the area of spacing hole on the piston, and the installation of magnetic sheet on the piston is unilateral fixed, can open the magnetic sheet top when cylinder piston rod promotes downwards, can block up the spacing hole in cylinder below with the magnetic sheet through magnetic force during upward movement. The design of cylinder below has the ring form boss, opens on the boss have with cylinder piston rod on the through-hole 20 that the sprue shape matches, the sprue on the cylinder piston rod and the through-hole on the ring form boss of cylinder are to lining up under the material state of annotating, can external solenoid valve realize the notes material of multiple interpolation material, the material gets into in the feed cylinder through the sprue of cylinder piston rod, notes material chamber, discharge gate.

4) Stirring/extrusion conditions:

when switching stirring extrusion state, the position of adjustment cylinder piston rod, its lower extreme is less than the feed cylinder upper surface a little during, rotates through servo motor and drives the stirring rake and stir, and the piston receives the restraint of cylinder piston rod and can't carry out synchronous rotation this moment, can only get into the feed cylinder down, gets into the feed cylinder after, and the piston no longer receives the restraint of cylinder piston rod, nevertheless can receive the restraint that lacks the structure in the feed cylinder, still can't rotate, can only continue downstream, realizes extruding of material in the feed cylinder.

Claims

1. A multi-station hot melt extrusion 3D printing nozzle is characterized by comprising a charging barrel (1), a stirring paddle (2), a piston (3), a cylinder (4) and a servo motor (5), wherein a heating barrel (12) is arranged outside the charging barrel (1); the charging barrel (1) is of a structure with a sealed bottom and an open top, a discharge hole (6) connected with the needle head is formed in the center of the bottom of the charging barrel, and the cross section of an inner cavity of the charging barrel is in a segment shape; the stirring paddle (2) is driven by a servo motor (5) and penetrates through the piston (3) to extend into the charging barrel (1); piston (3) for with feed cylinder (1) inner chamber assorted circle lack the form, piston (3) and stirring rake (2) threaded connection, just piston (3) have with cylinder piston rod (19) complex spacing hole.

2. The multi-station hot melt extrusion 3D printing nozzle as claimed in claim 1, wherein a magnetic sheet is arranged at the bottom of the limiting hole, and one side of the magnetic sheet is hinged with the bottom of the limiting hole; the cylinder piston rod (19) is internally provided with a material injection cavity (9), the top of the material injection cavity (9) is provided with a material injection port (10), and the bottom of the material injection port is provided with a material discharge port (11).

3. The multi-station hot melt extrusion 3D printing nozzle as claimed in claim 1, wherein a heating cavity for placing the charging barrel (1) is arranged in the heating barrel (12), two bosses (13) are arranged on the outer side wall of the charging barrel (1), two opposite sides of the cavity wall of the heating cavity are respectively provided with a strip-shaped groove (21), the strip-shaped groove (21) is vertically arranged upwards along the bottom of the heating cavity, and the top of the strip-shaped groove extends along the circumferential direction of the heating cavity to form an 1/4 arc-shaped groove (14).

4. A multi-station hot melt extrusion 3D printing nozzle as claimed in claim 3, wherein an upper cover (15) is arranged at the top of the heating barrel (12), a rack (16) is arranged in the middle of the upper cover (15), and the air cylinder (4) and the servo motor (5) are mounted at the rack (16).

5. A multi-station hot melt extrusion 3D printing nozzle as claimed in claim 4, wherein a concave clamping jaw (17) is arranged at the end of an output shaft of the servo motor (5), and a convex block (18) matched with the top end of the stirring paddle (2) is arranged at the top end of the stirring paddle.

6. A multi-station hot melt extrusion 3D printing nozzle as claimed in claim 1, wherein the paddle (2) has external threads in the middle to mate with the central hole of the piston (3).