KR101853431B1 - Extruder for 3-dimentional printer - Google Patents

Abstract

The present invention relates to an extruder for a 3D printer. The extruder for a 3D printer comprises: a body having a space portion formed therein; a filament guide installed to penetrate the space portion of the body to guide the filament; a synchronous double helical gear portion installed in the space portion to come into contact with both sides of the filament that passes through the inside of the filament guide to forcibly transfer the filament; an elasticity adjusting portion having a hinge shaft connected to one side of the body and providing an elastic force to the synchronous double helical gear portion to enhance a friction force between the synchronous double helical gear portion and the filament; and a driving portion connected and installed on the one side of the body to drive the synchronous double helical gear portion. In the synchronous double helical gear portion, a helical worm gear is engaged with a worm connected to a shaft of a driving unit to be rotationally driven, the helical driven gear engaged with the helical worm gear is synchronized, rotated, and driven, and an extrusion contact portions integrally connected to the helical worm gear and the helical driven gear are respectively brought into contact with the both sides of the filament, so that the filament can be pushed and forcibly transferred. Therefore, it is possible to prevent the filament from being damaged and to enhance the output speed and the output quality of the filament.

Description

Extruder for 3-dimentional printer

The present invention relates to an extruder for a 3D printer, which is applicable to a direct method and a Bowden method, in which a single motor and a synchronous double gear minimize the pressure applied to the filament in the lateral direction, To an extruder for a 3D printer which can be increased to the maximum.

A 3D printer is a device that creates objects by outputting continuous layers of materials like a two-dimensional printer and stacking them. It can quickly create objects based on digitized drawing information, In recent years, however, 3D printers are entering the commercialization stage because of technological basis that can be used for mass production of products with small quantity production of various types of products.

Generally, 3D printers are divided into a 3D printer method (additive type or rapid prototyping method) and a cutting type machining method (computer numerically controlled engraving method) in which a large layer is stacked according to a method of forming a three-dimensional form, Objects of three-dimensional shape can be variously determined.

The FDM (Fused Deposition Modeling) method is a typical example of the laminated type, and is called a FFF (Fused Filament Fragment) method. The filaments as the thermoplastic resin are used to further laminate layers from the bottom, Melted while passing through the extruder, and the melted material (filament) flows out through the nozzle and laminated to the output plate, so that it is molded into a necessary shape.

The above-mentioned stacking type method is advantageous in price compared to other 3D printers. In the stacked type 3D printer, the extruder is a very important part for determining the output speed and quality of the 3D printer.

The extruder has a direct method in which the extruding motor is positioned directly above the nozzle according to the position of the extruding motor to directly push out the filament, the nozzle driving unit is light, the device for compressing is located outside the printer, For correction, Teflon tube is divided into Bowden type which is connected with the head part and the pressing part so that high-speed output is easy.

A conventional direct extrusion type extruder is provided with a supply rotating body connected to a rotating shaft of a motor so as to contact one side of a filament, and an idle bearing is installed to contact the other side of the filament against the supply rotating body And the idle bearing is configured to be supported by the spring member so as to be in close contact with the filament.

That is, in the conventional direct extrusion type extruder, the filament is supplied to the nozzle side by the frictional force between the supply rotating body rotated by the motor and the filament, and the driving force of the motor is transmitted to only one side of the filament by the supply rotating body, As a result, the filaments supplied to the nozzles are deformed on one side, and the feeding efficiency of the filaments is lowered due to the unilateral deformation.

Further, in the conventional extruder, the idle bearing is urged in the direction of the filament by the spring member in order to increase the frictional force between the feed rotating body and the filament, so that a large resistance is generated in the filament and the deformation rate of the filament is further increased there was.

Particularly, in the conventional extruder, inelastic filaments are mostly used as materials, and there is a problem that an elastic filament such as thermoplastic polyurethane (TPU) or silicone can not be used.

That is, when the elastic filament is used as a material in a conventional extruder, since the length of the elastic filament is reduced in the axial direction, the cross-sectional area of the material is increased and a large resistance is generated. The printer can not output shoes, toys, daily necessities, and the like having elasticity.

Of course, in some 3D printers, elastic materials can be used as materials. However, such 3D printers are limited to expensive products, and there is no 3D printer that can be used by practitioners in general.

Patent Registration No. 10-1441030 (2014.09.06) Patent Registration No. 10-1720672 (Feb. Patent Registration No. 10-1432121 (Apr. 13, 2014)

SUMMARY OF THE INVENTION An object of the present invention is to provide an extruder for a 3D printer capable of increasing the extrusion pressure and minimizing the deformation of the cross-sectional area of the filament, thereby improving the output speed and output quality of the filament.

The present invention relates to a body having a space portion therein; A filament guide provided so as to pass through the space portion of the body and to guide the filament; A synchronous double helical gear part installed in a space of the body so as to be brought into contact with both sides of the filament passing through the inside of the filament guide to forcibly feed the filament; An elasticity adjusting part connected to a hinge shaft on one side of the body and increasing elasticity of the synchronous double helical gear to increase frictional force with the filament; And a driving unit connected to one side of the body to drive the synchronous double helical gear unit,

The synchronous double helical gear unit includes a helical worm gear engaged with a worm connected to a shaft of a driving unit, and a helical driven gear meshed with the helical worm gear is synchronously rotated to be rotationally driven and integrally connected to a helical worm gear and a helical driven gear And the extrusion contact portions are brought into contact with the both sides of the filament, respectively, so that the filament is forcedly fed by pushing.

According to the present invention, the rotational driving force of the driving unit is reduced and transmitted by the worm and the helical worm gear, and the helical worm gear and the helical driven gear having the opposite twist angle are engaged with each other to push the extrusion contacting portion from both sides of the filament, So that damage to the filament is prevented, and the output speed and output quality of the filament are improved.

According to the present invention, the weight of the driving unit can be minimized by the high reduction ratio of the worm and the helical worm gear, and the weight of the driving unit can be reduced.

The present invention can be applied to both a direct method and a Bowden method.

In the present invention, the extrusion contact portions of the first and second extruder gears are brought into contact with both sides of the filament, so that the deformation of the filament is reduced and the output of the filament is smoothly performed. And the maintenance cost is reduced.

The present invention is configured so as to be simple in structure, and is easy to maintain and can be assembled and manufactured at low cost.

According to the present invention, high-pressure delivery of filaments is possible, and density can be increased with high output speed and high filament pressure at the nozzle tip, thereby maximizing the quality of the output.

The present invention is configured such that the space portion of the body is opened by the elasticity adjusting portion, so that the operation of replacing the filament can be facilitated.

Since the pressure applied to the filament is low, the spring constant of the pressing spring can be lowered, thereby reducing damage to the filament.

Since the extrusion resistance hardly occurs when the filament is fed, the present invention can be applied not only to the filament made of the non-elastic material but also to the elastic filament made of the thermoplastic polyurethane (TPU) There are many effects that can be done.

1 is an illustration showing a configuration according to the present invention;
2 is an exemplary view showing the assembled state of the present invention
FIG. 3 is an exemplary view showing one side configuration according to the present invention.
Fig. 4 is an exemplary diagram showing the AA sectional structure of Fig. 3
5 is an exemplary view showing the BB sectional configuration of Fig. 3
6 is an exemplary diagram showing the structure of an extruder gear according to the present invention.
FIG. 7 is an exemplary view showing the connection relationship between the filament guide and the guide block according to the present invention
8 is an internal configuration example showing a filament forced feed state according to the present invention

3 is an exemplary view showing one side construction according to the present invention, and Fig. 4 is a sectional view taken along line 3-3 of Fig. 3. Fig. FIG. 6 is an exemplary view showing the structure of an extruder gear according to the present invention, and FIG. 7 is a view showing an example of an AA sectional structure of an AA according to the present invention. FIG. 8 is a view showing an example of the internal structure of the filament forcibly fed according to the present invention, and FIG.

The present invention includes a body (10) having a space (11) therein; A filament guide (20) provided so as to penetrate through the space (11) of the body and to guide the filament (F); A synchronous double helical gear portion 30 installed in the space portion 11 of the body so as to be brought into contact with both sides of the filament F passing through the inside of the filament guide 20 and for forcibly feeding the filament F; An elastic control unit 40 connected to a hinge shaft 41 at one side of the body 10 to increase the frictional force with the filament F by applying an elastic force to the synchronous double helical gear unit 30; And a driving unit (50) connected to one side of the body (10) and driving the synchronous double helical gear unit (30)

The synchronous double helical gear unit 30 includes a helical driven gear 35 engaged with the helical worm gear 34 and driven by a helical worm gear 34 driven by a worm 33 connected to the shaft 51 of the driving unit, The extrusion contact portions 36 and 37 integrally connected to the helical worm gear 34 and the helical driven gear 35 are brought into contact with the both sides of the filament F to push the filament F, To be transported.

As shown in FIGS. 1 and 2, the body 10 is provided with a driving part 50 fixed to one side thereof and a space part 11 having one side opened.

1, 4 and 7, the filament guide 20 has a hollow pipe shape in which a guide hole 21 for guiding the filament F is formed, and the guide hole 21 And the exposure openings 22 are formed to be symmetrical on both sides so as to communicate with the openings 21.

That is, the filament guide 20 is passed through the filament F into the guide hole 21 formed therein and the filament F in the guide hole 21 is guided by the filament guide 20 by the exposure opening 22, And is exposed to the outside.

The exposed opening 22 is formed in such a manner that the synchronous double helical gear portion 30 and the filament F are brought into contact with each other. The filament F is located in the filament guide 20 through the opening 22, One side of the synchronous double helical gear portion 30 is brought into contact with both sides and the filament F is forcibly transferred by the friction force between the synchronous double helical gear portion 30 and the filament F. [

4, 7 and 8, the guide block 60 supports the filament guide 20 to smoothly transfer the filament F to the space portion of the body 11).

The guide block 60 includes a through hole 61 through which the filament guide 20 is inserted, a fixing hole 62 provided so as to communicate perpendicularly to the through hole 61, And a fixing bolt 63 that is fastened to the fixing hole 62 so that an end of the filament guide 20 is in contact with the filament guide 20. The filament guide 20 positioned in the through hole 61 by the fixing bolt 63, Is fixedly supported.

The guide block 60 is fixedly installed in the space of the body so as to prevent interference between the worm of the synchronous double helical gear unit 30 and the helical worm gear and the helical driven gear.

The guide block 60 includes two semicircular type guide surfaces 64 and 65 at the upper end so as to prevent foreign matter from being inserted between the filament F and the extrusion contact portions 36 and 37 of the first and second extruder gears Respectively. That is, the two guide surfaces 64 and 65 are formed to maintain a predetermined distance from the extrusion contact portions 36 and 37 of the first and second extruder gears, and the two guide surfaces 64 and 65 Hole 61 is formed through the guide block 60. The through-

1, the synchronous double helical gear unit 30 includes a worm 33 integrally connected to a shaft of a driving unit so as to be positioned in a space of a body, a helical worm gear 33 rotated in engagement with the worm 33, (31) having a first gear (34) formed on one side thereof; A helical driven gear 35 which is meshed with another side of the helical worm gear 34 is formed on one side of the helical worm gear 34 so as to be symmetrical with respect to the first extruder gear 31 about the filament guide 20 And the extruded contact portions 36 and 37 of the first and second extruder gears are brought into contact with both sides of the filament F. The first and second extruder gears 32 and 37 are connected to each other.

The worm 33 is integrally fixed to the shaft 51 of the driving part to transmit the rotational driving force of the driving part to the helical worm gear 34.

The first extruder gear 31 receives the driving force of the driving unit 50 from the worm 33 and forcibly feeds the filament F by a frictional force. As shown in Figs. 1 and 4 to 6 A helical worm gear 34 which is rotatably supported on a first shaft 38 connected to the body 10 and is rotatably engaged with the worm 33 is formed at one side of the worm 33 and contacts the filament F And an extrusion contact portion 36 for generating a frictional force is formed on the other side.

As shown in FIGS. 1 and 4 to 6, the second extruder gear 32 is rotated by engaging with the helical worm gear 34 of the first extruder gear to forcibly feed the filament F A helical driven gear 35 which is rotatably supported on a second shaft 39 connected to the elasticity adjusting part 40 and rotated by being fitted to the helical worm gear 34 is formed on one side, F to generate a frictional force is formed on the other side.

That is, the worm 33, the helical worm gear 34 of the first extruder gear, and the helical driven gear 35 of the second extruder gear, as shown in FIG. 5, .

As shown in FIG. 4, the extrusion contact portions 36 and 37 of the first and second extruder gears are disposed symmetrically on both sides of the filament F, and contact with the filament F In order to increase the area and prevent the deformation of the filament, a concave shaped contact surface 36a, 37a is provided.

At this time, continuous contact irregularities may be formed on the contact surfaces 36a and 37a to prevent slippage and increase frictional force between the contact surfaces 36a and 37a. In other words, gears 36b and 37b having, for example, an apex and a valley may be formed on the contact surface of the extrusion contact portion.

The helical worm gear 34 of the first extruder gear and the helical driven gear 35 of the second extruder gear are formed to have a twist angle opposite to the rotational direction of the helical worm gear 34, The gear 31 is rotatably connected to the body 10 by a first shaft 38 and the second extender gear 32 is connected to the elasticity adjusting portion 40 by a second shaft 39 And is rotatably connected.

In the synchronous double helical gear unit 30 constructed as described above, the extruding pressure of the filament F is increased by the high deceleration of the worm 33 and the helical worm gear 34, and the first and second extruder gears 31, 32 and the filament F, the frictional force is increased to provide a high filament extrusion pressure despite the low axial pressure.

Particularly, the synchronous double helical gear unit 30 is configured such that the extrusion contact portions 36 and 37 of the first and second extruder gears contact the both sides of the filament F to forcibly feed the filament F, Deformation and damage of the filament F are prevented, whereby the clogging of the nozzle is minimized, and the output speed and output quality of the filament are improved.

The elastic adjustment portion 40 presses the second extender gear 32 toward the filament F so that the helical worm gear 34 of the first extruder gear and the helical driven gear 35 of the second extruder gear And has a function of supplying the filaments uniformly through the frictional force between the extrusion contact portions 36 and 37 and the filament F of the first and second extruders.

1 and 5, the elastic adjustment portion 40 is rotatably connected to the body 10 by a hinge shaft 44, and is connected to the second extruder 40 by a second shaft 39, A lever block 41 to which the gear 32 is connected and a pressure adjusting knob 42 which penetrates the lever block 41 and is fastened to the coupling hole 12 of the body, And a pressing spring 43 which is installed between the adjusting knob 42 and applies an elastic force to press the lever block 41 in the direction of the body 10.

That is, the resilient adjusting portion 40 is provided so that the helical driven gear 35 of the second extruder gear is engaged with the helical worm gear 34 of the first extruder gear, The lever block 41 is rotated about the hinge shaft 44 so that the contact portion contact surface 36a contacts the filament F and the pressure adjusting knob 42 is engaged with the engaging hole 12 of the body, The lever block 41 is pressed toward the body 10 by the elastic force of the pressing spring 43 to increase the frictional force between the filament F and the pushing contact portions 36 and 37. [

At this time, the lever block 41 is rotated around the hinge shaft 44 to close the open side of the body space part, thereby blocking foreign matter from entering into the space part.

2, the driving unit 50 is fixedly installed on one side of the body 10 to generate rotational power of the first and second extruder gears 31 and 32 so that the filament F is fed . Such a drive unit may be provided with a motor as an example.

Reference numeral 70 in FIG. 8 denotes a nozzle mount portion to be coupled to the body 10; 80, a heater portion for melting the filament F forcibly fed from the filament guide 20; And injects the melted filament in the nozzle 80.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims and their equivalents. Of course, such modifications are within the scope of the claims.

(10): Body (11): Space part
(12): coupling hole (20): filament guide
(21): Guide hole (22): Exposure opening
(30): a synchronous double helical gear unit (31): a first extruder gear
(32): second extruder gear (33): worm
(34): Helical worm gear (35): Helical driven gear
(36): extrusion contact portion (37): extrusion contact portion
(36a, 37a): contact surfaces (36b, 37b): gear
(38): first axis (39): second axis
(40): elasticity adjusting portion (41): lever block
(42): pressure adjusting knob (43): pressure spring
(44): Hinge shaft (50): Driving motor part
(51): shaft (60): guide block
(61): Through hole (62): Fixing hole
(63): Fixing bolts (64, 65): Guide surface
(70): nozzle mounter (80): heater part
(90): nozzle

Claims (4)

A body 10 having a space 11 therein;
A filament guide (20) provided so as to penetrate through the space (11) of the body and to guide the filament (F);
A synchronous double helical gear portion 30 installed in the space portion 11 of the body so as to be brought into contact with both sides of the filament F passing through the inside of the filament guide 20 and for forcibly feeding the filament F;
An elastic control unit 40 connected to a hinge shaft 41 at one side of the body 10 to increase the frictional force with the filament F by applying an elastic force to the synchronous double helical gear unit 30;
And a driving unit (50) connected to one side of the body (10) and driving the synchronous double helical gear unit (30)
The synchronous double helical gear unit 30 includes a worm 33 integrally connected to the shaft of the driving unit so as to be positioned in the space of the body and a helical worm gear 34 rotated to engage with the worm 33 A first extruder gear 31; A helical driven gear 35 which is meshed with another side of the helical worm gear 34 is formed on one side of the helical worm gear 34 so as to be symmetrical with respect to the first extruder gear 31 about the filament guide 20 And a second extruder gear (32) connected and installed,
The elastic regulating portion 40 includes a lever block 40 rotatably connected to the body 10 by a hinge shaft 44 and a second shaft 39 connected to the second through- A pressure regulating knob 42 which penetrates through the lever block 41 and is fastened to the coupling hole 12 of the body and a lever 41 which is provided between the lever block 41 and the pressure regulating knob 42, And a pressing spring 43 for applying an elastic force to press the block 41 in the direction of the body 10,
The helical worm gear 34 is rotationally driven by being engaged with the worm 33 connected to the shaft 51 of the driving part and the helical driven gear 35 engaged with the helical worm gear 34 is synchronously rotated to be driven, Extrusion contact portions 36 and 37 integrally connected to the helical driven gear 35 and the helical driven gear 35 contact the both sides of the filament F to push the filament F forcibly. more.
The method of claim 1,
A guide block 60 for supporting the filament guide 20 and for smoothly conveying the filament F is further provided in the space 11 of the body,
The guide block 60 includes a through hole 61 through which the filament guide 20 is inserted, a fixing hole 62 provided so as to communicate perpendicularly to the through hole 61, And a fixing bolt 63 that is fastened to the fixing hole 62 so that an end of the filament guide 20 is in contact with the filament guide 20. The filament guide 20 positioned in the through hole 61 by the fixing bolt 63, Is fixedly supported.
delete The method of claim 1,
The first extruder gear 31 is rotatably supported on a first shaft 38 connected to the body 10 and a helical worm gear 34 rotatably engaged with the worm 33 is formed on one side , An extrusion contact portion (36) for generating a frictional force in contact with the filament (F) is formed on the other side,
The second extruder gear 32 is supported by a second shaft 39 rotatably supported on a second shaft 39 connected to the elasticity adjusting portion 40 and is rotatably supported by a helical driven gear 35 Is formed on one side, an extrusion contact portion (37) for generating frictional force in contact with the filament (F) is formed on the other side,
The extrusion contact portions 36 and 37 of the first and second extruder gears are formed so as to be symmetrically positioned on both sides of the filament F with recessed contact surfaces 36a and 37a contacting the filament Extruder for 3D printers featuring.

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