JP2021094821A - Molding device and molding method - Google Patents

Abstract

To provide a molding device and a molding method of forming a molded article by a multipath system, capable of suppressing overcure of ink dots formed from ink droplets which have been ejected previously.SOLUTION: A molding device 1 comprises: an inkjet head 20 for ejecting ink droplets of a curable ink which is cured corresponding to light of a prescribed wavelength toward a molding table 16; and a light source 22 for irradiating ink dots formed by ink droplets landed on the molding table 16 with light. The inkjet head 20 conducts forming a molded article 30 by a multipath system wherein the inkjet head 20 performs a plurality of times of main scan movements of ejecting ink droplets while moving toward a prescribed main scan direction toward each position of a molding region of the molding table 16 where forming of a molded article 30 is conducted, and also, among the plurality of times of the main scan movements toward each position, luminous intensity irradiated from the light source 22 is made smaller than that in the previous time.SELECTED DRAWING: Figure 1

Description

The present invention relates to a modeling apparatus and a modeling method.

In recent years, modeling devices for forming three-dimensional objects have become widespread. As such a modeling device, an ink jet head is used to eject ink as a material for a modeled object, and the ejected ink is cured by ultraviolet rays or the like to form an ink layer, and the layer is flattened by a flattening roller. , An apparatus has been developed for forming a modeled object by repeating lamination.

Here, Patent Document 1 discloses a modeling apparatus that forms a modeled object by a multipath method. The multi-pass method is, for example, a method in which in the operation of forming one ink layer, a main scanning operation is performed a plurality of times for each position, and ink droplets are ejected a plurality of times for each position. .. This makes it possible to form a higher-definition modeled object.

Japanese Unexamined Patent Publication No. 2018-184009

However, the ink dots formed by the ink droplets ejected by the multipath method may be overcured because the ink dots formed earlier are repeatedly irradiated with ultraviolet rays or the like. When the ink dots are over-cured, the modeled object may be warped, and the strength and color may be affected. Further, when flattened by the flattening roller, the shavings of the overharded portion may adhere to the modeled object again and become a stain on the modeled object.

Therefore, an object of the present invention is to provide a modeling apparatus and a modeling method capable of suppressing overcuring of ink dots formed by ink droplets ejected earlier when forming a modeled object by a multipath method.

The modeling apparatus of the present invention has an inkjet head that ejects ink droplets of curable ink that cures in response to light of a predetermined wavelength toward the modeling table, and ink dots formed by the ink droplets that land on the modeling table. In a modeling apparatus provided with a light source for irradiating the light and forming a modeled object by laminating the ink dots, the inkjet head is a region to be modeled in which the modeled object is formed on the modeling table. The modeled object is formed by a multi-pass method in which the main scanning operation of ejecting ink droplets is performed a plurality of times while the inkjet head moves in a predetermined main scanning direction with respect to a position, and a plurality of the shaped objects are formed for each position. Of the main scanning operations of the times, the illuminance emitted from the light source is reduced in the previous times.

According to this configuration, when forming a modeled object by the multipath method, the integrated light amount of light for curing the ink dots formed by the previously ejected ink droplets can be suppressed, so that the formed object is formed first. Overcuring of ink dots can be suppressed.

According to the modeling apparatus of the present invention, the light source may gradually increase the illuminance so as to increase the illuminance to the ink dots formed later. According to this configuration, overcuring of the ink dots formed earlier can be suppressed.

According to the modeling apparatus of the present invention, the light source sets the illuminance to the ink dots formed last as the illuminance at which the ink dots are completely cured, and the illuminance to the ink dots formed before the last. May be the illuminance at which the ink dots are not completely cured. According to this configuration, overcuring of the ink dots formed earlier can be suppressed.

According to the modeling apparatus of the present invention, the light source may irradiate the light so that the integrated light amounts of the plurality of ink dots formed at the respective positions are equal. According to this configuration, the degree of curing of a plurality of ink dots formed at each position of the modeling table can be made equal.

The modeling method of the present invention is formed by a first step in which an inkjet head ejects ink droplets of curable ink that cures in response to light of a predetermined wavelength toward a modeling table, and the ink droplets that land on the modeling table. In a modeling method, which comprises a second step in which a light source irradiates the ink dots with the light, and the first step and the second step are repeated to stack the ink dots to form a modeled object. The inkjet head performs a main scanning operation of ejecting ink droplets while the inkjet head moves in a predetermined main scanning direction with respect to each position of a modeled region in which the modeled object is formed on the modeling table. The modeled object is formed by a multi-pass method performed a plurality of times, and the illuminance emitted from the light source is reduced in the previous of the multiple main scanning operations for each position.

INDUSTRIAL APPLICABILITY The present invention can suppress overcuring of ink dots formed by ink droplets ejected earlier when forming a modeled object by a multipath method.

It is a schematic block diagram of the modeling apparatus of embodiment. It is a schematic diagram which shows the number of times of ink droplet ejection by the multi-pass method, (A) shows the case of 2 passes, and (B) shows the case of 4 passes. It is a schematic diagram which shows the integrated light amount for each ink dot, (A) shows the integrated light amount when the illuminance in each pass is the same in 2 passes, (B) is the case where the illuminance in each pass is the same in 4 passes. The integrated light amount is shown, and (C) shows the integrated light amount when the illuminance is reduced as the illuminance becomes smaller in the four passes. It is a functional block diagram about the multipath illuminance control of embodiment. It is a flowchart which shows the flow of the multipath illuminance control processing of the modeling apparatus of embodiment.

Hereinafter, the modeling method and the modeling apparatus according to the embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing the configuration of the modeling apparatus 1 of the present embodiment. As an example, the modeling device 1 is configured as a system having a 3D printer 10, a user PC 40, and a control PC 42.

The 3D printer 10 of the present embodiment includes a discharge unit 12, a scanning drive unit 14, a modeling table 16, a movable unit 17, and a control device 18, and is three-dimensional by solidifying and laminating the cured resin discharged from the discharge unit 12. It is an inkjet type 3D printer that forms a three-dimensional object 30.

The discharge unit 12 discharges the material of the modeled object 30 and stacks the layers constituting the modeled object 30 layer by layer to form the modeled object 30 on the modeling table 16. More specifically, the ejection unit 12 is based on the ink jet head 20 that ejects ink droplets containing various inks and support materials that are the materials of the modeled object 30 toward the modeling table 16 and the ink droplets that land on the modeling table 16. The left light source 22A and the right light source 22B that irradiate the formed ink dots with light of a predetermined wavelength to cure them, and the upper surface (hereinafter referred to as "laminated surface") of the ink dots formed during the modeling of the modeled object 30 are flattened. The flattening roller 24 is provided. In the example of FIG. 1, three inkjet heads 20 are shown, but the number of inkjet heads 20 can be appropriately set according to the number of types of ink used.

The light having a predetermined wavelength emitted from the light source 22 to the ink dots is, for example, ultraviolet rays. That is, the ink droplets ejected from the inkjet head 20 are curable inks (curable resins) that are cured in response to ultraviolet rays.

As described above, the ejection unit 12 of the present embodiment ejects ink droplets or the like of a curable resin that is cured by irradiation with ultraviolet rays and cures the ink droplets to form each layer constituting the modeled object 30. Specifically, the ejection unit 12 ejects ink droplets in response to an instruction from the control device 18 to form a layer of a curable resin and a curable resin formed by the layer forming operation. The curing operation of curing the layer is repeated a plurality of times to form the modeled object 30.

The scanning drive unit 14 is a drive unit that moves the discharge unit 12 relative to the modeled object 30 (hereinafter referred to as “scanning operation”). The scanning drive unit 14 causes the discharge unit 12 to perform a main scanning operation (Y scanning) and a sub scanning operation (X scanning) as scanning operations. Here, the main scanning operation is, for example, an operation in which the ejection unit 12 reciprocates in a preset main scanning direction (Y direction in the drawing) to eject ink droplets.

The scanning drive unit 14 has a carriage 32 and a guide rail 34. The carriage 32 is a holding portion that holds the discharge unit 12 so as to face the modeling table 16. That is, the carriage 32 holds the ejection unit 12 so that the ejection direction of the ink droplets is in the direction toward the modeling table 16. Further, during the main scanning operation, the carriage 32 moves along the guide rail 34 while holding the discharge unit 12. The guide rail 34 is a rail-shaped member that guides the movement of the carriage 32, and moves the carriage 32 in response to an instruction from the control device 18 during the main scanning operation.

The movement of the discharge unit 12 in the main scanning operation may be a movement relative to the modeled object 30. For example, the modeled object 30 may be moved by fixing the position of the discharge unit 12 and moving the modeling table 16.

The movable portion 17 makes the distance between the discharge unit 12 and the modeling table 16 variable. That is, the upper surface of the modeling table 16 can be moved in the vertical direction (Z direction in FIG. 1) by the movable portion 17, and the upper surface moves according to the instruction of the control device 18 as the modeling of the modeled object 30 progresses. To do. As a result, the distance (gap) between the surface to be modeled in the modeled object 30 in the process of modeling and the discharge unit 12 is appropriately adjusted. Here, the modeled surface of the modeled object 30 is, for example, a surface on which the next layer is formed by the discharge unit 12. The scanning in the Z direction in which the modeling table 16 is moved up and down with respect to the discharge unit 12 may be performed by, for example, moving the side of the discharge unit 12.

The control device 18 is, for example, a CPU (Central Processing Unit) of the 3D printer 10, and controls each part of the 3D printer 10 based on slice data showing shape information of the modeled object 30 to be modeled, color image information, and the like. This controls the modeling operation of the modeled object 30.

The user PC 40 is an information processing device having a display device 40A and an input device 40B composed of a keyboard, a mouse, and the like. The user PC 40 of the present embodiment transmits 3D model data showing the modeled object 30 in a predetermined format to the control PC 42 as a modeling job. The 3D model data is data indicating the shape of the modeled object 30 and its surface color, etc., and is created based on, for example, 3DCAD data, data on the appearance of the modeled object 30 to be manufactured, and the like.

The control PC 42 is an information processing device that controls the 3D printer 10, and receives a modeling job from the user PC 40. The control PC 42 generates slice data corresponding to the cross section of each position of the modeled object 30 based on the modeling job (3D model data) received from the user PC 40. Then, the control PC 42 transmits the slice data corresponding to each position to the 3D printer 10. In the example of FIG. 1, one 3D printer 10 is connected to the control PC 42, but this is an example, and a plurality of 3D printers 10 may be connected to the control PC 42.

The user PC 40 and the control PC 42 include, for example, a CPU that performs arithmetic processing, a ROM (Read Only Memory) that stores programs and various data in advance, a RAM (Random Access Memory) that is used as a work area of the CPU, and It is equipped with a storage device such as an HDD (Hard Disk Drive) that stores various information, and transmits and receives various data to and from another information processing device and the 3D printer 10.

The inkjet head 20 of the present embodiment is a main scanning operation that ejects ink droplets while moving in the main scanning direction (Y direction) with respect to each position of the modeled area where the modeled object 30 is formed on the modeling table 16. The modeled object 30 is formed by a multi-pass method in which the above is performed a plurality of times. More specifically, the ejection of ink droplets in the outward movement of the inkjet head 20 by the first main scanning operation is set as the first pass, the ejection of ink droplets in the return path movement is set as the second pass, and the second main scanning operation is performed. The outbound movement and the inbound movement are the third and fourth passes, respectively.

As described above, the multi-pass method makes it possible to form a higher-definition modeled object 30 by forming three or more ink dots at each position of the modeled area. As an example, the multi-pass of the present embodiment is a 4-pass in which the main scanning operation is performed twice and ink droplets are ejected four times at each position in the area to be modeled.

2A and 2B are schematic views showing the number of times ink droplets are ejected by the multi-pass method, in which FIG. 2A shows the case of 2 passes and FIG. 2B shows the case of 4 passes. The region C shown in FIG. 2 indicates each position where ink droplets are ejected, and ink droplets are ejected a plurality of times according to the number of passes to this region C to form ink dots. Further, each rectangular region included in the region C indicates an ink droplet ejection position, and a numerical value indicates the number of passes for ejecting the ink droplet to the position indicated by the rectangular region. That is, in the example of FIG. 2B, ink droplets are ejected in the order of the first pass, the second pass, the third pass, and the fourth pass from the left side of the paper surface at each position indicated by the area C. The order in which the ink droplets are ejected at each position is not limited to this. For example, ink droplets may be ejected in the order of the first pass, the third pass, the second pass, and the fourth pass from the left side of the paper surface at each position.

FIG. 3 is a schematic diagram showing the integrated light amount for each ink dot, (A) shows the integrated light amount when the illuminance in each pass is the same in 2 passes, and (B) shows the illuminance in each pass in 4 passes. Indicates the integrated light amount when is the same, and (C) indicates the integrated light amount when the illuminance is reduced as the illuminance becomes smaller in the four passes. Further, the 1-pass illuminance shown in FIG. 3 indicates the magnitude of the illuminance of the ultraviolet rays emitted from the light source 22 each time each ink dot is formed. Although the value indicating the illuminance (light amount) does not indicate the actual value, the illuminance "10" is exemplified as a value capable of completely curing the ink dots.

Here, the ink dots formed in the first pass are also irradiated with ultraviolet rays to the ink dots formed in the second pass. Therefore, the ink dots formed earlier have a larger integrated light amount than the ink dots formed later. For example, in FIG. 3A, the integrated light amount of the ink dots formed in the first pass is twice the integrated light amount of the ink dots formed in the second pass.

Further, in the example of FIG. 3B, the integrated light amount of the ink dots formed in the first pass is four times the integrated light amount of the ink dots formed in the fourth pass. The integrated light amount of the ink dots formed in the 4th pass is excessive, and the ink dots formed in the 4th pass are overcured. If the ink dots are over-cured, the modeled object 30 may be warped or the strength and color may be affected. Further, when flattened by the flattening roller 24, the shavings of the overharded portion may adhere to the modeled object 30 again and become a stain on the modeled object 30.

Therefore, the modeling device 1 of the present embodiment forms the modeled object 30 by the multipath method, and is irradiated from the light source 22 in the previous of the plurality of main scanning operations for each position (region C). Control to reduce the illuminance (hereinafter referred to as "multipath illuminance control") is performed.

FIG. 3C shows the integrated light amount of each ink dot in the multipath illuminance control. In the example of FIG. 3C, the illuminance of the first pass is "2", the illuminance of the second pass is "3", the illuminance of the third pass is "5", and the illuminance of the fourth pass. Is "10". Therefore, the integrated light amount of the first pass is "20", the integrated light amount of the second pass is "18", the integrated light amount of the third pass is "15", and the integrated light amount of the fourth pass is "10". Become.

As shown in FIG. 3 (C), by performing the multi-pass illuminance control, the integrated light intensity of the final 4th pass is the same as the integrated light intensity of the 2nd pass in the 2-pass shown in FIG. 3 (A). It becomes. As described above, the multipath illuminance control of the present embodiment determines the integrated amount of light for curing the ink dots formed by the ink droplets ejected earlier when the modeled object 30 is formed by the multipath method. Since it can be suppressed, overcuring of the ink dots formed earlier can be suppressed.

Further, as described above, the light source 22 of the present embodiment gradually increases the illuminance so as to increase the illuminance to the ink dots formed later. In the present embodiment, the illuminance of the first pass is the first illuminance, the illuminance of the second pass is the second illuminance, the illuminance of the third pass is the third illuminance, and the illuminance of the fourth pass is the fourth illuminance. The relationship between the magnitudes of each illuminance is 1st illuminance <2nd illuminance <3rd illuminance <4th illuminance. The magnitudes of the first illuminance, the second illuminance, the third illuminance, and the fourth illuminance are set in advance.

Further, in the light source 22, the illuminance to the ink dots formed last is the illuminance at which the ink dots are completely cured, and the illuminance to the ink dots formed before the last is completely cured by the ink dots. Do not use illuminance. That is, the fourth illuminance is a magnitude that completely cures the ink dots, while the first illuminance, the second illuminance, and the third illuminance may be the illuminance that makes the ink dots semi-cured. As a result, over-curing of the ink dots formed earlier can be suppressed, and the ink dots formed last can be completely cured.

The magnitudes of the first illuminance, the second illuminance, the third illuminance, and the fourth illuminance may be the same, for example, first illuminance = second illuminance = third illuminance <fourth illuminance. .. Further, the illuminance to the ink dots formed at the end may be an illuminance at which the ink dots are not completely cured. In this case, the ink dots formed at the end are completely cured by the ultraviolet rays irradiated to cure the ink dots laminated on the ink dots.

Further, the light source 22 may irradiate light so that the integrated light amounts of the plurality of ink dots formed at each position are the same. The term "equivalent" as used herein means, for example, that the difference between the ink dots having the largest integrated light intensity and the ink dots having the smallest integrated light intensity is twice or less. As a result, the degree of curing of the plurality of ink dots formed at each position of the modeling table 16 can be made equal.

FIG. 4 is a functional block diagram relating to the modeling process executed by the 3D printer 10 of the present embodiment. The control device 18 included in the 3D printer 10 includes a scanning control unit 50, a path determination unit 52, an ink ejection control unit 54, and a light source control unit 56.

The scanning control unit 50 has a scanning drive unit 14 so that the discharge unit 12 moves in the main scanning direction (Y direction) and the sub-scanning direction (X direction) and the modeling table 16 moves in the vertical direction (Z direction). And the drive of the movable portion 17 is controlled.

The path determination unit 52 determines the current number of passes of the inkjet head 20 that is moving in the main scanning direction of the ejection unit 12 (outward movement or return movement), in other words, the main scanning movement while ejecting ink droplets. To do.

The ink ejection control unit 54 controls the inkjet head 20 so as to eject ink droplets based on the slice data transmitted from the control PC 42.

The light source control unit 56 controls the illuminance from the light source 22 based on the determination result of the path determination unit 52. That is, the ink dots formed in the first pass are irradiated with the first illuminance, the ink dots formed in the second pass are irradiated with the second illuminance, and the ink formed in the third pass is irradiated. The dots are irradiated with the third illuminance, and the ink dots formed in the fourth pass are irradiated with the fourth illuminance.

FIG. 5 is a flowchart showing the flow of the multipath illuminance control process of the modeling apparatus 1 of the present embodiment. The multipath illuminance control process shown in FIG. 5 is executed as a part of the modeling process.

First, in step S100, the path determination unit 52 determines the current number of paths.

In the next step S102, the inkjet head 20 ejects ink droplets corresponding to the number of passes determined in step S100 toward the modeling table 16.

In the next step S104, the light source 22 irradiates the ink dots formed by the ink droplets landing on the modeling table 16 with ultraviolet rays having an illuminance corresponding to the number of passes determined in step S100.

In the next step S106, it is determined whether or not the formation of the modeled object 30 is completed, and in the case of an affirmative determination, the main modeling process is terminated, while in the case of a negative determination, the process returns to step S100, and steps S100 to S104 are performed. The modeled object 30 is formed by repeatedly laminating ink dots.

Although the present invention has been described above using the above-described embodiment, the technical scope of the present invention is not limited to the scope described in the above-described embodiment. Various changes or improvements can be made to the above embodiments without departing from the gist of the invention, and the modified or improved forms are also included in the technical scope of the present invention. In addition, the above embodiments may be combined as appropriate.

In the above embodiment, the embodiment in which the multipal is set to 4 passes has been described, but the present invention is not limited to this. For example, the multipath may be 3 passes or more.

In the above embodiment, the mode in which the light of a predetermined wavelength irradiated by the light source 22 is ultraviolet rays has been described, but the present invention is not limited to this. For example, if the photocurable ink (resin) can be cured, the light source 22 may irradiate light of another wavelength such as infrared rays.

In the above embodiment, a mode in which the modeling apparatus 1 is configured as a system having a 3D printer 10, a user PC 40, and a control PC 42 has been described, but the present invention is not limited thereto. For example, an information processing device having the functions of the user PC 40 and the control PC 42 may be connected to the 3D printer 10.

(Effect of embodiment)
(1) The modeling apparatus 1 of the present embodiment uses an inkjet head 20 that ejects ink droplets of curable ink that cures in response to light of a predetermined wavelength toward the modeling table 16 and ink droplets that land on the modeling table 16. In the modeling apparatus 1 which includes a light source 22 for irradiating the formed ink dots with light and forms the modeled object 30 by laminating the ink dots, the inkjet head 20 forms the modeled object 30 on the modeling table 16. The modeled object 30 is formed by a multi-pass method in which the inkjet head 20 performs a main scanning operation of ejecting ink droplets a plurality of times while moving in a predetermined main scanning direction at each position of the area to be modeled. Of the plurality of main scanning operations for each position, the illuminance emitted from the light source 22 is reduced in the previous operation.

According to the present embodiment, when the modeled object 30 is formed by the multipath method, the integrated light amount of light for curing the ink dots formed by the previously ejected ink droplets can be suppressed, so that the formed object 30 is formed first. It is possible to suppress over-curing of the ink dots to be formed.

(2) According to the modeling apparatus 1 of the present embodiment, the light source 22 gradually increases the illuminance so as to increase the illuminance to the ink dots formed later. According to this embodiment, overcuring of the ink dots formed earlier can be suppressed.

(3) According to the modeling apparatus 1 of the present embodiment, the light source 22 sets the illuminance to the ink dots formed at the end to the illuminance at which the ink dots are completely cured, and the ink dots formed before the end. The illuminance to is defined as the illuminance at which the ink dots are not completely cured. According to this embodiment, overcuring of the ink dots formed earlier can be suppressed.

(4) According to the modeling apparatus 1 of the present embodiment, the light source 22 may irradiate the light so that the integrated light amounts of the plurality of ink dots formed at the respective positions are the same. According to this embodiment, the degree of curing of the plurality of ink dots formed at each position of the modeling table 16 can be made equal.

The present invention relates to a modeling apparatus that forms a three-dimensional object by ejecting ink.

1 Modeling device 16 Modeling table 20 Inkjet head 22 Light source 30 Modeled object

Claims (5)

An inkjet head that ejects ink droplets of curable ink that cures according to light of a predetermined wavelength toward the modeling table,
A light source that irradiates the ink dots formed by the ink droplets that land on the modeling table with the light.
In a modeling apparatus for forming a modeled object by laminating the ink dots.
The inkjet head performs a main scanning operation of ejecting ink droplets while the inkjet head moves in a predetermined main scanning direction with respect to each position of a modeled region in which the modeled object is formed on the modeling table. A modeling device that forms the modeled object by a multi-pass method that is performed a plurality of times, and reduces the illuminance emitted from the light source the earlier of the plurality of main scanning operations for each position. The modeling apparatus according to claim 1, wherein the light source gradually increases the illuminance so as to increase the illuminance to the ink dots formed later. In the light source, the illuminance to the ink dots formed last is the illuminance at which the ink dots are completely cured, and the illuminance to the ink dots formed before the end is the illuminance at which the ink dots are completely cured. The modeling apparatus according to claim 1 or 2, wherein the illuminance is not set. The modeling apparatus according to any one of claims 1 to 3, wherein the light source irradiates the light so that the integrated light amounts of the plurality of ink dots formed at the respective positions are equal to each other. The first step in which the inkjet head ejects ink droplets of curable ink that cures in response to light of a predetermined wavelength toward the modeling table, and
A second step in which the light source irradiates the ink dots formed by the ink droplets landing on the modeling table with the light.
Have,
In a modeling method in which a modeled object is formed by laminating the ink dots by repeating the first step and the second step.
The inkjet head performs a main scanning operation of ejecting ink droplets while the inkjet head moves in a predetermined main scanning direction with respect to each position of a modeled region in which the modeled object is formed on the modeling table. A modeling method in which the modeled object is formed by a multi-pass method performed a plurality of times, and the illuminance emitted from the light source is reduced the earlier of the plurality of main scanning operations for each position.

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