KR101704620B1 - FDM 3D printer for output error correction, and correction method using of it - Google Patents

Abstract

The present invention relates to an extrusion lamination type 3D printer capable of correcting an output error, a printer head for controlling the amount and speed of filaments transferred from a filament spool, An extruder that extends to a lower end of the printer head and discharges the filament downward and stacks the filament on a sample stage; A stage driving unit for moving the sample stage in the Z axis direction according to printing information; An output error sensor for measuring a real time height of a sample printed in front of and behind the printer head in a printing moving direction; A printing controller for controlling the printer head, the extender, and the stage driver according to printing information; And an output error correction unit for calculating output error information having different heights of the sample through the information received from the output error sensor, calculating correction information according to the calculated output error information, and feeding back the information to the printing control unit.
According to the present invention, it is possible to measure or scan output errors in the form of grooves or protrusions in real time. Based on this information, it is possible to easily control the extruder amount of the extruder in the next layer stacking at the position point of output error detection So that accurate correction can be performed.

Description

Technical Field [0001] The present invention relates to an extrusion lamination type 3D printer capable of correcting an output error, and an output error correction method using the same.

The present invention relates to a 3D printer and an output error correction method, and more particularly, to an extrusion lamination type 3D printer capable of real-time output error scanning, detection and correction, and an output error correction method using the same.

Generally, in order to produce a prototype having a three-dimensional solid shape, a method of making a cooperative work by hand and a method of manufacturing by CNC milling are widely known depending on drawings.

However, since the method of making the woodwork is by hand, elaborate numerical control is difficult and time consuming, and CNC milling can produce precise numerical control, but there are many shapes that are difficult to process due to tool interference.

In recent years, so-called three-dimensional printing methods have been developed for product designers and designers to generate three-dimensional modeling data using CAD or CAM, and to produce prototypes of three-dimensional shapes using the generated data. The printer is used in various fields such as industry, life, and medicine.

A 3D printer is a manufacturing apparatus for producing objects by outputting successive layers of materials as a two-dimensional printer and stacking them. 3D printers can be used to create prototypes quickly because they can be quickly created based on digitized drawing information.

The product molding method of the 3D printer includes a method of molding a light-scraped material with a laser beam to form a light-shaded portion, an extrusion molding method, and a method of melting and laminating a thermoplastic filament (FDM) have.

Among such methods, a 3D printer using a method of melting and laminating filaments has a lower production cost than other types of 3D printers, and a 3D printer using filaments is becoming popular for home and industrial use.

Meanwhile, the filament for the 3D printer is formed of PLA, which is a thermoplastic resin which is harmless to the human body and the environment, as a material, and a crystal nucleating agent such as talc is added depending on the use of the product to increase the strength. In addition, since PLA is weak in heat resistance and flame retardancy compared to other synthetic resins, it is possible to increase the heat resistance by using talc as a crystal nucleus depending on the use of the product to be molded, OH) 2, Al (OH) 3 and the like may be used as a filler to increase the heat resistance.

Korean Patent No. 10-1346704 discloses a 3D printer capable of forming a multicolor product by having a plurality of nozzles as a related art related to a 3D printer. However, in the case of a 3D printer of the FDM (Fused Deposition Modeling) method, the following problems may occur in extruders which continuously feed and supply filaments.

That is, FIG. 1 is a vertical cross-sectional view of a heater nozzle 20 according to the prior art. The filament 3 has a structure in which a pair of guide rollers 35 are guided to the introduction hole 22 by friction during rotation, Wear of the pair of guide rollers 35 occurs during use, which makes smooth guidance difficult. Also, if the filaments 3 are not supplied smoothly and irregularly, there is a problem that the shape of the object to be printed is not formed as required.

The output error of the layer lamination caused by the supply of filaments or the defective amount of the extruded matter affects the shape of the entire printing molding, thereby causing a quality deterioration. Therefore, a technology capable of detecting such output error in real time And a technique for correcting this is desperately required.

Korean Registered Patent No. 10-1441030 (Registered Date: September 05, 2014)

An object of the present invention to solve the above problems is to provide a method and apparatus for detecting an error that may occur in print lamination in real time and controlling an extruder to control the discharge amount of a filament solution to facilitate errors such as grooves or protrusions An extrusion lamination type 3D printer capable of precisely correcting errors, and an output error correction method using the same.

According to a first aspect of the present invention, there is provided a printer comprising: a printer head for controlling the amount and speed of filaments transferred from a filament spool to be transferred vertically downward; An extruder that extends to a lower end of the printer head and discharges the filament downward and stacks the filament on a sample stage; A stage driving unit for moving the sample stage in the Z axis direction according to printing information; A front error sensor installed in front of the line in the line direction in which the printer head moves and measuring a height of a previous layer in real time, and a front error sensor installed in the rear of the line, extruded from the extruder, An output error sensor including a rear error sensor for measuring the height of the vehicle in real time; And calculating an average value of the height of the uppermost layer layer printed on the basis of the average value of the height difference between the previous layer and the current layer, and calculating an average value of the current layer height value and an average value An output error corrector for calculating output error information including an error position and an error depth when the difference is equal to or greater than a predetermined value and generating correction information according to the calculated output error information when the error is determined; And a printing controller for controlling an output error of the extruder by controlling the extrusion amount of the filament solution of the extruder by controlling the printer head and the stage driver in the stacking of the next layer based on the correction information, .

Preferably, the output error sensor may be a laser sensor or an ultrasonic sensor. According to the printing information, the printer head may be moved in the X and Y axes, and the stage may be moved in the Z axis.

Further, it is preferable that a heating block for melting the filament is installed between the printer head and the extruder.

A second aspect of the present invention is summarized as a method for correcting an output error of 3D printing using the above-described extrusion lamination type 3D printer, the method comprising the steps of: (a) Measuring a height in real time; (b) measuring the height of the current layer after the rear error sensor is extruded and printed in the extruder in real time; (c) receiving the measured information from the output error correcting unit, calculating an average value of the printed top layer layer height based on an average value of the height difference between the previous layer and the current layer, Calculating output error information including a position and an error depth of an error when the difference in the average value of the layer heights is equal to or greater than a predetermined value, and generating correction information according to the calculated output error information; And (d) the printing control unit controls the printer head and the stage driving unit to move to the position of the error in the lamination of the next layer based on the correction information, and controls the extrusion amount of the filament solution of the extruder And correcting the output error.

Preferably, the output error sensor is a laser sensor or an ultrasonic sensor. According to the printing information, the printer head is moved in the X and Y axes, and the stage is moved in the Z axis, And a heating block for melting the filament between the extruder.

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According to the present invention, it is possible to measure or scan output errors in the form of grooves or protrusions in real time. Based on this information, it is possible to easily control the extruder amount of the extruder in the next layer stacking at the position point of output error detection So that accurate correction can be performed.

It is another object of the present invention to provide an apparatus and a method for detecting and correcting an output error precisely and quickly by installing a simple structure without greatly changing the structure of a conventional extrusion lamination type 3D printer. It can be effectively improved.

1 is a longitudinal sectional view of a heater nozzle by an FDM 3D printer in the prior art,
2 is a view illustrating a configuration of an extrusion lamination type 3D printer capable of output error correction according to an embodiment of the present invention,
FIG. 3 is a flow chart illustrating an output error correction method of an extrusion-lamination type 3D printer according to an embodiment of the present invention,
4 and 5 are diagrams illustrating a method of detecting and correcting errors using an output error correction method of an extrusion lamination type 3D printer according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 2 is a view showing a configuration of an extrusion lamination type 3D printer capable of output error correction according to an embodiment of the present invention. As shown in FIG. 2, the extrusion lamination type 3D printer according to the embodiment of the present invention is an extrusion lamination type 3D printer in which a printer head (not shown) for controlling the amount and speed of filaments transferred from a filament spool, 100); An extruder (200) extending to the lower end of the print head (100) and discharging the filament downward and stacking the filament on a sample stage; A stage driving unit 300 for moving the sample stage in the Z-axis direction according to the printing information; An output error sensor 150 for measuring a real time height of a sample printed in front and rear of the print head in a printing movement direction; A printing control unit 400 for controlling the printer head 100, the extender 200, and the stage driving unit 300 according to printing information; And an output error sensor 150 for calculating output error information having different heights of the sample from the information received from the output error sensor 150 and calculating correction information according to the calculated output error information, (500).

As described above, the present invention is not limited to the error detecting and correcting function when the sculpture is produced by the conventional extrusion lamination (FDM) 3D printer, so that even if a single error occurs from the beginning to the end of stacking, In order to solve the problem causing quality deterioration, a sensor is mounted on the printer head 100 to detect an error that may occur in print stacking in real time, and based on the error information received from the sensor, The printing control unit 400 receives the generated correction information and controls the extruder 200 for discharging the solution of the filament to control the emission of the filament solution to correct errors such as grooves or protrusions A 3D printer that can be used in a variety of applications.

Specifically, as shown in FIG. 2, the extrusion lamination type 3D printer capable of performing output error correction according to the embodiment of the present invention is configured such that a filament made of a thermoplastic resin is fed by a filament spool, The filament is supplied and moved downward. The filament is melted to form a solution on the lower end of the print head 100, and the filament solution is discharged to the stage by the printing information received by the printing control unit 400, and is laminated on a layer basis.

 Layer-by-layer lamination is a process in which the printer head 100 capable of moving in the X and Y axes forms a line and deposits a filament solution. The lines are horizontally stacked to form one layer, And the driving unit of the sample stage moves along the Z axis again, and the next layer is laminated.

In this process, when the conventional extrusion lamination type 3D printer generates an output error on any one of the layers and forms a groove or a protrusion, according to information of the preset printing controller 400, The output of the filament solution is determined and printed, so that it is output without the process of correcting at the error point, which results in the error having a great influence on the quality of the entire printed image.

Thus, in the extrusion lamination type 3D printer of the present invention, the error sensor 150 such as a laser sensor is installed in front of and behind the printing line in the printer head 100, And outputs the detection information to the output error correcting unit 500. The output error correcting unit 500 generates correction information based on the information and then sends the correction information to the printing control unit 400. [ A 3D printer which can control the output of the filament solution by controlling the extruder 200 based on the correction information received by the printing control unit 400 and correct errors in the formation of the next layer line of the point where the error is detected .

Here, the error sensor 150 may be an optical sensor such as a laser sensor as a distance sensor or an ultrasonic sensor, but a more precise distance sensor is preferable because the layer height or thickness is in micro units.

The laser sensor irradiates the layer stacked on the stage with laser light and receives the reflected laser light to measure the distance. One of the laser sensors is installed in front of the printer head 100 in the line direction in which the printer head 100 moves And another one pair is formed on the rear side thereof to detect a layer stack output error. Here, the mounting position may be provided on a side portion of the printer head 100, or may be provided on the front and rear of the extender 200 through a support base.

The laser sensor in front of the printing line of the layer measures the height of the previous laser, i.e., the layer before the printing lamination layer, and the rear laser sensor measures the height of the layer immediately after the printing line lamination, So that a change can be detected or detected.

When an output error of the printing line is detected through the error sensor 150, the error information is transmitted to the output error correction unit 500, and the output error correction unit 500 generates correction information based on the error information And then sent to the printing control unit 400. Since the printing control unit 400 precisely controls the movement of the printing head through the CNC numerical control, it is possible to accurately detect the position of the error. Based on the correction information, The amount of output or the amount of extrusion of the ink cartridge 200 is controlled and corrected.

It is preferable that a heating block 250 for melting a filament is installed between the printer head 100 and the extruder 200 because the filament is thermoplastic resin and melts by applying heat, The heating block 250 is required to be heated by the nozzle and the amount of extrusion or the speed of the nozzle 250 can be easily controlled by controlling the heating temperature of the heating block 250. [ And can be precisely controlled.

When the grooves are formed in the printing line, the extrusion amount control of the extruder 200 by the correction information is performed by increasing the extrusion amount at the position in the line stacking of the next layer, It is possible to reduce the amount of extrusion in line stacking and to correct it to be equal to the height of a normal line.

As described above, the extrusion lamination type 3D printer capable of output error correction according to the embodiment of the present invention detects an error (grooves, projections, etc.) that can be generated in line stacking of a layer by using a laser sensor or the like, It is possible to detect and output a precise 3D printer output error with a simple device configuration by proposing a structure in which the correction information is generated and the correction information is transmitted to the printer control unit and the printing control unit 400 controls the extrusion amount of the extruder 200 Thereby providing an improved extrusion lamination type 3D printer capable of correcting it.

3 is a flowchart illustrating an output error correction method of an extrusion lamination type 3D printer according to an embodiment of the present invention. 3, an output error correction method of a 3D printer according to an exemplary embodiment of the present invention is an output error correction method of 3D printing using the above-described extrusion lamination type 3D printer. The method includes (a) (S100) measuring the height of the previous layer in real time by the front error sensor (150) while the printer head (100) moves; (b) measuring the height of the current layer after the rear output error sensor 150 is extruded and printed in the extruder 200 in real time (S200); (c) receiving the measured information from the output error correcting unit 500 and calculating an average value of the height of the printed top layer (S300); (d) if the output error correcting unit 500 determines that the difference between the current layer height value and the average value is equal to or greater than a predetermined value, generating error information including the error position and the error depth S400); And (e) controlling the extruder 200 based on the error information so that the printing controller 400 corrects the output error in the stacking of the next layer (S500).

The embodiment of the present invention proposes a method of correcting an output error using the above-described 3D printer. In this embodiment, by efficiently exchanging information between the error sensor 150, the output error correction unit 500 and the printing control unit 400, And corrects the extrusion amount of the filament solution in the extruder 200 to easily correct the layer line printing error.

That is, in the embodiment of the present invention, two sensors are attached to the front and rear of the extrusion head of the printer head 100 of the extruder 200 through a laser sensor capable of measuring the height up to a micro-unit in real time, The height of the layer line is scanned by the sensor and when an error occurs, the extrusion amount of the extruder 200 is controlled and compensated through the output error correction unit 500 and the printing control unit 400 .

For example, when the laser sensor positioned in front of the printer head 100 scans the height of the previous layer of the N-1 layer and the height of the printed layer line is scanned in real time by the rear laser sensor Code data of the printing information previously obtained by the output error correcting unit 500 to increase the extrusion amount when the height is low and the correction information to decrease the extrusion amount when the height is high, It is corrected at the N layer layer lamination at that position.

4 and 5 are diagrams illustrating a method of detecting and correcting errors using an output error correction method of an extrusion lamination type 3D printer according to an embodiment of the present invention. Fig. 3 shows the case where the error is the groove, and Fig. 4 shows the case where the error is the protrusion.

As shown in FIGS. 4 and 5, when the method according to the embodiment of the present invention is applied, it is possible to measure the height or the thickness of the layer line in which the stacked layer lines are changed before and after the printing line stacking. That is, if the difference between the height of the previous layer and the height of the layer after the line stacking is calculated, the height or thickness of the line to be printed can be measured. A method for detecting an error is to measure the height of a previous layer and a printing laminated layer in real time every hour, calculate an average value of the layer line heights currently stacked by printing, and then calculate a difference between the average value and the height value of the current layer line If it is out of the set range, it can be judged that there is an error.

This real-time scanning method can detect not only an error detection method by comparing the data on the G-codes already obtained, but also a method of directly detecting an error through data of a real-time scanning laser sensor.

In the output error correction method of the extrusion lamination type 3D printer according to the embodiment of the present invention, an error that appears in the form of a groove or a protrusion due to an error in the extrusion amount of the extruder (200) The height is measured or scanned in real time through a laser sensor installed at the front and rear of the printing apparatus 100. Based on the information, the output error correction unit 500 generates correction information, and the printing control unit 400 The extrusion amount of the extruder 200 is controlled at the position of the error detection in the stacking of the next layer, so that the precise correction can be performed.

100: printer head, 150: error sensor, 200: extruder,
250: heating block, 300: stage driving unit, 400: printing control unit
500: output error correction unit

Claims (11)

In an extrusion lamination type 3D printer,
A printer head for controlling the amount and speed of the filaments transferred from the filament spool and transferring the filaments to a vertically downward direction;
An extruder that extends to a lower end of the printer head and discharges the filament downward and stacks the filament on a sample stage;
A stage driving unit for moving the sample stage in the Z-axis direction according to printing information;
A heating block installed between the printer head and the extruder to melt the filament;
A front error sensor installed in front of the line in the line direction in which the printer head moves and measuring a height of a previous layer in real time, and a front error sensor installed in the rear of the line, extruded from the extruder, An output error sensor including a rear error sensor for measuring the height of the vehicle in real time;
And calculating an average value of the height of the uppermost layer layer printed on the basis of the average value of the height difference between the previous layer and the current layer, and calculating an average value of the current layer height value and an average value An output error corrector for calculating output error information including an error position and an error depth when the difference is equal to or greater than a predetermined value and generating correction information according to the calculated output error information when the error is determined; And
In the lamination of the next layer based on the correction information,
The CNC numerical control moves the printer head in the X and Y axes, moves the sample stage in the Z axis to the error position, controls the extrusion amount of the filament solution through heating temperature control of the heating block, However,
Wherein the extrusion amount control is performed by increasing the extrusion amount of the filament solution at the position of the moved error when the grooves are formed in the printing line and correcting the extrusion amount of the filament solution at the position of the moved error, And a printing controller for correcting an output error by correcting the output error by correcting the output error.
The method according to claim 1,
Wherein the output error sensor comprises:
A laser sensor or an ultrasonic sensor.
An output error correction method for 3D printing using an extrusion lamination type 3D printer according to claim 1,
(a) measuring a height of a previous layer in real time by the front error sensor while moving the printer head according to a layer stack printing;
(b) measuring the height of the current layer after the rear error sensor is extruded and printed in the extruder in real time;
(c) receiving the measured information from the output error correcting unit, calculating an average value of the printed top layer layer height based on an average value of the height difference between the previous layer and the current layer, Calculating output error information including a position and an error depth of an error when the difference in the average value of the layer heights is equal to or greater than a predetermined value, and generating correction information according to the calculated output error information; And
(d) The printing controller moves the print head in X and Y axes through CNC numerical control in the stacking of the next layer based on the correction information, moves the sample head in the Z axis, And controlling an extrusion amount of the filament solution through heating temperature control of the heating block,
Wherein the extrusion amount control is performed by increasing the extrusion amount of the filament solution at the position of the moved error when the grooves are formed in the printing line and correcting the extrusion amount of the filament solution at the position of the moved error, And correcting an output error by correcting the output error by reducing the output error of the 3D printer.
The method of claim 3,
Wherein the output error sensor comprises:
A laser sensor or an ultrasonic sensor.
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