Multi-phase three-dimensional printing apparatus capable of realizing delicate control of flow for forming molded object

Abstract

A multiphase three-dimensional (3D) printing apparatus is disclosed. According to the present invention, there is provided a bidirectional pressure control unit capable of controlling the pressure in both directions of a positive pressure for accelerating the flow of the first material forming the molded object and a negative pressure for decelerating or braking the flow of the first material, so that the flow of the first material can be ingeniously controlled, such as, for example, the flow of the first material can be controlled. According to the invention, a control tool capable of controlling the flow of the first material in real time in the molding process can be provided, so that the coating volume per unit time can be correctly filled; the scanning line is set on the basis of the width of the scanning line forming the transfer path of the first ejection unit for ejecting the flow of the first material and the length of the scanning line per unit time corresponding to the transfer speed of the first ejection unit.

Description

Technical Field

[0001] This invention relates to a multiphase three-dimensional (3D) printing apparatus. Background Technology

[0002] A 3D printing device is a tool used to mold objects with specific shapes. For example, it takes cross-sectional data of a shape to be molded as input and creates the shape by stacking layers of the shape. In such a 3D printing device, the three-dimensional shape of the object to be molded can be generated as digital data through computer modeling, differentiated in a two-dimensional plane, and then the differentiated material can be continuously stacked to create a three-dimensional shape. Summary of the Invention

[0003] Technical issues

[0004] One embodiment of the present invention may include a multiphase three-dimensional (3D) printing apparatus, including a bidirectional pressure control unit. Because the bidirectional pressure control unit is capable of controlling the flow of a first material with a positive pressure for accelerating the flow of the first material or a negative pressure for decelerating or braking the flow of the first material, the flow of the first material can be precisely controlled in real time during the molding process to accurately fill a coating volume per unit time set based on the width of the scan line and the length of the scan line per unit time. The width of the scan line forms the transport path of a first ejection unit for ejecting the flow of the first material, and the width of the scan line per unit time corresponds to the transport speed of the first ejection unit.

[0005] Technical solution

[0006] To address the problems described above and others, the multiphase 3D printing apparatus of the present invention includes:

[0007] The first nozzle is used to discharge the liquid first material that forms the shape onto the worktable;

[0008] A heating funnel, connected to the first nozzle and filled with a liquid first material; and

[0009] A bidirectional pressure control unit is connected to the heating funnel and is used to alternately reverse the pressure difference between the inside and outside of the heating funnel between positive and negative pressure, and is used to i) accelerate the flow of the first material from the heating funnel toward the first nozzle according to the positive pressure, and ii) decelerate the flow of the first material from the heating funnel toward the first nozzle or apply braking to the flow of the first material according to the negative pressure.

[0010] Beneficial effects

[0011] According to the present invention, a multiphase 3D printing apparatus can be provided, including a bidirectional pressure control unit. Because the bidirectional pressure control unit is capable of controlling the flow of a first material with a positive pressure for accelerating the flow of the first material to form a model or a negative pressure for decelerating or braking the flow of the first material, the flow of the first material can be precisely controlled in real time during the modeling process, for example, to correctly fill a coating volume per unit time set based on the width of the scan line and the length of the scan line per unit time, wherein the width of the scan line forms the transport path of a first ejection unit for ejecting the flow of the first material, and the width of the scan line per unit time corresponds to the transport speed of the first ejection unit. Attached Figure Description

[0012] Figure 1 An overall perspective view of a multiphase three-dimensional (3D) printing apparatus according to an embodiment of the present invention is shown.

[0013] Figure 2 Showing Figure 1 The diagram shows some of the components of a multiphase 3D printing device.

[0014] Figure 3 Show Figure 1 The multiphase 3D printing apparatus shown is illustrated along... Figure 2 A cross-sectional view of line III-III.

[0015] Figure 4 Showing the description in Figure 1 The multiphase 3D printing apparatus shown illustrates the molding of a shape formed from the first and second ejection positions on the worktable S, which ejects different materials M1 and M2, and the molding of a shape within the filling space surrounded by the shape outline.

[0016] Figure 5 For use in describing Figure 1 The figure shows the extrusion device 80, which is illustrated. Figure 1 A schematic diagram of the extrusion device 80 is shown.

[0017] Figure 6 To show Figure 1 An exploded perspective view of a portion of a multiphase 3D printing apparatus is shown, illustrating the sealing structure of the heating funnel 10 and the sealing cap CV, which are joined together by a sealing gasket GA.

[0018] Figure 7 To show Figure 1 The diagram shows a portion of a multiphase 3D printing apparatus, illustrating the flow resistance that causes pressure loss in the flow of liquid first material M1 from the heating funnel 10 toward the first nozzle 10a.

[0019] Figure 8 To show Figure 1 The diagram shows a portion of a multiphase 3D printing apparatus, illustrating that the pressure difference PIO between the interior of the heating funnel 10 and the patch is set to positive pressure to accelerate the flow of liquid first material M1 from the heating funnel 10 toward the first nozzle 10a.

[0020] Figure 9 To show Figure 1 As shown in part of a multiphase 3D printing apparatus, the pressure difference PIO between the inside and outside of the heating funnel 10 is set to a negative pressure to slow down or brake the flow of liquid first material M1 from the heating funnel 10 toward the first nozzle 10a.

[0021] Figures 10A to 10D The different variation curves are shown, which respectively show along the time axis the holding capacity of the first material M1 contained inside the heating funnel 10, the flow resistance that causes pressure loss in the flow of the liquid first material M1 from the heating funnel 10 toward the first nozzle 10a, the pressure difference PIO between the inside and outside of the heating funnel 10 set to keep the flow of the liquid first material M1 ejected from the first nozzle 10a in a stable state, and the change of the volumetric flow rate of gas GAS to keep the flow of the liquid first material M1 ejected from the first nozzle 10a in a stable state over time.

[0022] Figure 11 For use in describing Figure 1 The figure shows an embodiment of the bidirectional pressure control unit 100, which schematically illustrates the bidirectional control unit 100 controlling the injection and discharge of gas gas into and out of the heating funnel 10 to set the pressure difference between the inside and outside of the heating funnel 10 to positive and negative pressure.

[0023] Figure 12 For use in describing Figure 1 The figure shows another embodiment of the bidirectional pressure control unit 100, which schematically illustrates the bidirectional pressure control unit 100 that controls the gas gas injection and gas gas gas discharge to the heating funnel 10 to set the pressure difference PIO between the inside and outside of the heating funnel 10 to be bidirectional, positive and negative.

[0024] Figure 13 For use in describing Figure 1 A figure of another embodiment of the bidirectional pressure control unit 100 is shown, which controls the gas gas injection and gas gas gas gas discharge to the heating funnel 10 to set the pressure difference PIO between the inside and outside of the heating funnel 10 to be bidirectional, i.e., positive and negative pressure.

[0025] Figure 14A diagram showing the width w of the scan line SL, which is used to describe the transfer path followed by the first material M1 along the shape area surrounded by the shape outline formed by the second material, which is set to scan as a whole.

[0026] Figure 15 This is a graph used to describe the coating volume V per unit time, which is based on... Figure 14 The scan line SL along the transport path has a width w dimension, a cross-sectional area of ​​the scan line SL, and a length L of the scan line SL per unit time set according to the transport speed.

[0027] Figures 16A to 16C A diagram illustrating the ON / OFF control signals of the first to third fluid valves 111, 121, and 131 output from the valve controller 150 over time.

[0028] Figure 17 This diagram illustrates the coating termination interval ST between the end position FP of the scan line SL in the first turn and the start position SP of the scan line SL in the second turn, as described in the molding process of an object formed by the accumulation of the first material in the first nozzle along the conveying path of the first nozzle that ejects the first material, according to an embodiment of the present invention.

[0029] Figures 18A to 18C The graph shows the variation curves of the stepped pressure difference between the inside and outside of the heating funnel, the control signal for controlling the opening of the second fluid valve which follows the stepped pressure difference between the inside and outside of the heating funnel, and the opening / closing control signal of the third fluid valve as control targets.

[0030] Figure 19 This is a diagram used to describe the activity intervals T1 and T2 of the first nozzle 10a and the second nozzle 20a, which are divided into mutually exclusive time slots in the molding process used to form a shaped object.

[0031] Best mode

[0032] To address the problems described above and others, the multiphase 3D printing apparatus of the present invention includes:

[0033] The first nozzle is used to spray the liquid first material that forms the shape onto the worktable;

[0034] A heating funnel, connected to the first nozzle and filled with a liquid first material; and

[0035] A bidirectional pressure control unit is connected to the heating funnel and is used to alternately reverse the pressure difference between the inside and outside of the heating funnel between positive and negative pressure, and is used to i) accelerate the flow of the first material from the heating funnel toward the first nozzle according to the positive pressure, and ii) decelerate the flow of the first material from the heating funnel toward the first nozzle or apply braking to the flow of the first material according to the negative pressure.

[0036] For example, the bidirectional pressure control unit can apply a brake to the flow of the first material from the heating funnel toward the first nozzle by setting the pressure difference between the inside and outside of the heating funnel to a negative pressure.

[0037] For example, the bidirectional pressure control unit can set the pressure difference between the inside and outside of the heating funnel to a negative pressure, or set it to include negative pressure pulses that apply and block negative pressure to provide suction force toward the heating funnel to prevent the flow of the first material from being ejected from the heating funnel toward the first nozzle.

[0038] For example, the bidirectional pressure control unit can

[0039] At the end position of the transfer path of the first nozzle or at the end position of the scan line forming the transfer path of the first nozzle, the pressure difference between the inside and outside of the heating nozzle is set to a negative pressure, or set to a negative pressure pulse that includes the application and blocking of negative pressure.

[0040] For example, the bidirectional pressure control unit

[0041] Along the transfer path of the first nozzle or the scan line forming the transfer path of the first nozzle, in the interval between the end position and the start position of the scan line, the pressure difference between the inside and outside of the heating funnel can be set to negative pressure, or set to a negative pressure pulse that includes the application and interruption of negative pressure.

[0042] For example, when forming a shape through the accumulation of preceding and subsequent turns and the stacking of preceding and subsequent layers,

[0043] Along the transport path of the first nozzle, the end position and start position of the scan line forming the transport path of the first nozzle can be between the leading turn and the trailing turn, and between the leading layer and the trailing layer.

[0044] For example, along the conveying path of the first nozzle,

[0045] The end position of the scan line in the preceding turn and the start position of the scan line in the subsequent turn; and

[0046] A coating stop interval is formed between the end position of the scan line in the preceding layer and the start position of the scan line in the subsequent layer, and...

[0047] The bidirectional pressure control unit can set the pressure difference between the inside and outside of the heating funnel to a negative pressure in the coating stop space, or set it to a negative pressure pulse that includes the application and interruption of negative pressure.

[0048] For example, the multiphase 3D printing device

[0049] It further includes a second nozzle for spraying a second material to form the outline of the shape, and,

[0050] In order to block the ejection of the first material when the second material is ejected, the bidirectional pressure control unit can set the pressure difference between the inside and outside of the heating funnel to a negative pressure, or set it to include a negative pressure pulse that includes the application and blocking of negative pressure.

[0051] For example, the active range of the first nozzle, in which the first and second nozzles, which are connected to each other, are moved together along the conveying path of the first nozzle.

[0052] The active range of the second nozzle, in which the first and second nozzles, which are connected to each other, are moved together along the conveying path of the second nozzle.

[0053] The molding process used to form the object can be divided into mutually exclusive time periods.

[0054] For example, the bidirectional pressure control unit may include

[0055] A first fluid valve is used to connect the tube bundle to the first fluid tube and the connection of the first fluid tube of the heating funnel;

[0056] A second fluid valve is used to connect the tubing bundle to the second fluid pipe and the second fluid pipe of the positive pressure source;

[0057] A third fluid valve is used for connecting the tubing bundle to a third fluid pipe and the connection of the third fluid pipe to a negative pressure source; and

[0058] Valve controller, which is used to control the first to third fluid valves, wherein,

[0059] The valve control can control the opening / closing of the second fluid valve and the opening / closing of the third fluid valve.

[0060] For example, the valve controller

[0061] The opening / closing of the second fluid valve and the opening / closing of the third fluid valve can be alternately controlled to be inconsistent with each other, and exclusively controlled to include partial overlap or non-overlap between each other along the time axis.

[0062] For example, the valve controller can control the opening / closing and the opening degree of the second fluid valve and the opening / closing and the opening degree of the third fluid valve.

[0063] For example, the valve controller

[0064] While controlling the reduction of the opening degree of the second fluid valve, the sequential opening and closing control of the third fluid valve can also be achieved.

[0065] For example, the valve controller

[0066] It can output a control signal with a sloping ramp waveform having a first rise time or a first fall time to control the reduction of the opening of the second fluid valve, and

[0067] A control signal with a pulse waveform having a second rise time or a second fall time shorter than the first rise time or the first fall time is output to achieve sequential control of the opening and closing of the third fluid valve.

[0068] For example, the bidirectional pressure control unit can

[0069] Based on the insufficient coating volume of the first material per unit time set according to the transfer path and transfer speed of the first nozzle, the pressure difference between the inside and outside of the heating funnel is set to a positive pressure to accelerate the flow of the first material from the heating funnel toward the first nozzle, or

[0070] The pressure difference between the inside and outside of the heating funnel is set to a negative pressure based on the interference of the coating volume of the second material per unit time, which is set according to the transfer path and transfer speed of the first nozzle, to reduce or brake the flow of the first material from the heating funnel toward the first nozzle.

[0071] For example, based on the coating volume of the first material per unit time set according to the transfer path and transfer speed of the first nozzle, the pressure difference between the inside and outside of the heating funnel is set to positive or negative pressure to accelerate or decelerate the flow of the first material from the heating funnel toward the first nozzle, or to brake the flow of the first material.

[0072] The coating volume of the first material per unit time can be calculated based on the product of the width of the scan line forming the transfer path or the cross-sectional area of ​​the scan line including the width and height dimensions of the scan line and the length of the scan line per unit time equivalent to the transfer speed.

[0073] For example, the heating funnel includes a circumferential surface that is wider at the top and narrower at the bottom, and its inner diameter gradually decreases from the upper inlet where the metal block of the first material is fed in to the bottleneck portion of the first nozzle connected to the lower end from which the liquid first material is ejected.

[0074] The flow friction caused by the heating funnel and the bottleneck portion that restricts the flow of the first material in liquid state may cause pressure loss to the flow of the first material.

[0075] For example, when the heating funnel is filled with a limited capacity and then ejected from inside the heating funnel onto an external worktable, the pressure loss caused by the flow of the first material from inside the heating funnel toward the outside may be reduced.

[0076] For example, the bidirectional pressure control unit,

[0077] With the first material ejected from the inside of the heating funnel toward the outside of the worktable kept in a constant steady-state, the pressure difference between the inside and outside of the heating funnel can be controlled to ensure that...

[0078] i) The pressure difference between the inside and outside of the heating funnel decreases together to offset the pressure loss caused by the ejection of the first material, or

[0079] ii) The reduction in the weight of the first material and the reduction in pressure loss due to the ejection of the first material acting in the opposite direction to the flow of the first material are offset from each other and the pressure difference between the inside and outside of the heating funnel remains the same.

[0080] For example, the multiphase 3D printing apparatus may further include

[0081] A sealing cap, which covers and seals the inlet at the upper end of the heating funnel and is engaged with the heating funnel; and

[0082] A sealing gasket, used to seal the space between the heating funnel and the sealing cap.

[0083] For example, the heating funnel includes a sealing flange formed along the outer peripheral edge of the upper inlet, and,

[0084] The sealing gasket may be located between the sealing flange of the heating funnel and the sealing cap, and is joined to each other by means of engagement through which the sealing flange of the heating funnel and the plate-shaped sealing cap are formed side by side.

[0085] For example, the bidirectional pressure control unit may include

[0086] A first fluid tube extends from the common confluence location toward the heating funnel;

[0087] A second fluid conduit, connected from the common confluence location to a positive pressure source; and

[0088] The third fluid pipe connects to the negative pressure source from the common confluence location.

[0089] For example, the bidirectional pressure control unit may further include,

[0090] A first fluid valve is connected on the first fluid pipe between the common confluence location and the heating funnel;

[0091] A first pressure gauge is connected on the first fluid tube between the heating funnel and the first fluid valve;

[0092] A second fluid valve is connected on the second fluid pipe between the common confluence location and the positive pressure source;

[0093] A second pressure gauge is connected on the second fluid tube between the positive pressure source and the second fluid valve;

[0094] A third fluid valve, connected on the third fluid pipe between the common confluence location and the negative pressure source; and

[0095] And a third pressure gauge, which is connected on the third fluid tube between the negative pressure source and the third fluid valve.

[0096] For example, the bidirectional control unit may further include

[0097] A valve controller is connected to each of the first to third fluid valves and is used to apply control signals to each of the first to third fluid valves to control the opening and closing of the valve and the degree of valve opening.

[0098] For example, the valve controller

[0099] The first and second fluid valves can be controlled to open to set the pressure difference between the inside and outside of the heating funnel to a positive pressure, and...

[0100] The first and third fluid valves can be controlled to be opened to set the pressure difference between the inside and outside of the heating funnel to a negative pressure.

[0101] For example, the multiphase 3D printing apparatus further includes

[0102] The second nozzle is used to form a paste-like or slurry-like second material into the outline of the object, and...

[0103] The width of the scan line forming the transfer path of the first nozzle can be set to scan the entire modeling area, wherein a model is formed that is equivalent to a fill space surrounded by the outline of the model formed by the second material.

[0104] For example, the multiphase 3D printing apparatus may further include

[0105] An extrusion device connected to the second nozzle and extruding the second material into the second nozzle to spray out a paste or slurry-like second material consisting of ceramic particles and a matrix in which the ceramic particles are dispersed.

[0106] For example, the multiphase 3D printing device

[0107] The heating chamber, which accommodates the worktable, also provides a slow cooling space for the first and second materials accumulated on the worktable from the first and second nozzles, and...

[0108] Based on the atmospheric pressure of the slow-cooling space in the heating chamber, the pressure difference between the inside and outside of the heating funnel can be equivalent to the internal pressure of the heating funnel containing the liquid first material. Detailed Implementation

[0109] Hereinafter, with reference to the accompanying drawings, a multiphase three-dimensional (3D) printing apparatus according to a preferred embodiment of the present invention will be described.

[0110] A multiphase 3D printing apparatus according to an embodiment of the present invention may include:

[0111] The first nozzle 10a is used to spray the liquid first material M1 that forms the shape onto the worktable S;

[0112] Heating funnel 10, which is connected to the first nozzle 10a and filled with liquid first material M1; and

[0113] A bidirectional pressure control unit 100 is connected to the heating funnel 10 and is used to alternately reverse the pressure difference PIO between the inside and outside of the heating funnel 10 between positive and negative pressure, and is used to i) accelerate the flow of the first material M1 from the heating funnel 10 toward the first nozzle 10a according to the positive pressure, and ii) decelerate the flow of the first material M1 from the heating funnel 10 toward the first nozzle 10a or to brake the flow of the first material M1 according to the negative pressure.

[0114] According to one embodiment of the present invention, the bidirectional pressure control unit 100 can

[0115] The pressure difference PIO between the inside and outside of the heating funnel 10 is set to a negative pressure to brake the flow of the first material M1 from the heating funnel 10 toward the first nozzle 10a.

[0116] According to one embodiment of the present invention, the bidirectional pressure control unit 100 can

[0117] The pressure difference PIO between the inside and outside of the heating funnel 10 is set to a negative pressure to provide a suction force toward the heating funnel 10 to prevent the flow of the first material M1 from being ejected from the heating funnel 10 toward the first nozzle 10a.

[0118] According to an embodiment of the present invention, the heating funnel 10 includes

[0119] The circumferential surface, wider at the top and narrower at the bottom, has an inner diameter that gradually decreases from the upper inlet where the metal block of the first material M1 is fed in to the bottleneck portion BN of the first nozzle 10a, which connects to the lower end where the liquid first material M1 is discharged.

[0120] The flow friction acting from the circumferential surface of the heating funnel 10 and the bottleneck portion BN that restricts the flow of the first material M1 may cause pressure loss in the flow of the first material M1.

[0121] According to one embodiment of the present invention,

[0122] When the first material M1, which fills the interior of the heating funnel 10 with a limited capacity, is ejected from the interior of the heating funnel 10 onto the external worktable S, the pressure loss caused by the flow of the first material M1 from the interior of the heating funnel 10 toward the exterior may be reduced.

[0123] According to one embodiment of the present invention, the bidirectional pressure control unit 100 can

[0124] The pressure difference PIO between the inside and outside of the heating funnel 10 is controlled under a steady-state condition where the ejection rate of the first material M1 on the worktable S from the inside of the heating funnel 10 toward the outside is kept constant, so that...

[0125] i) The pressure difference between the inside and outside of the heating funnel 10 is reduced together to offset the pressure loss caused by the ejection of the first material M1, or

[0126] ii) The reduction in the weight of the first material and the reduction in pressure loss of the first material acting in the opposite direction to the flow of the first material are offset from each other and the pressure difference between the inside and outside of the heating funnel remains the same.

[0127] According to one embodiment of the present invention, the bidirectional pressure control unit 100 can

[0128] The pressure difference PIO between the inside and outside of the heating funnel 10 is set to a positive pressure to counteract the pressure loss caused by the flow of the first material M1 from the inside of the heating funnel 10 toward the outside.

[0129] The positive pressure can be set to gradually decrease to offset the pressure loss caused by the ejection of the first material M1, or the decrease in the weight of the first material M1 and the decrease in pressure loss caused by the ejection of the first material M1 can be offset by each other, thereby setting the positive pressure to a constant level.

[0130] According to one embodiment of the present invention, the bidirectional pressure control unit 100 can

[0131] Gas GAS, which accumulates inside the heating funnel 10 and forms an internal pressure PI in the heating funnel 10, is injected into the heating funnel 10 to set the pressure difference PIO between the inside and outside of the heating funnel 10 to a positive pressure, or

[0132] The gas GAS that accumulates inside the heating funnel 10 and forms the internal pressure PI of the heating funnel 10 is discharged from the heating funnel 10 to set the pressure difference PIO between the inside and outside of the heating funnel 10 to a negative pressure.

[0133] According to one embodiment of the present invention, the bidirectional pressure control unit 100 can

[0134] The volumetric flow rate of gas GAS is provided to fill the volume of the ejected first material M1, so that the ejection amount of the first material M1 from the inside of the heating funnel 10 toward the outside of the worktable S is always kept in a steady-state, and the volumetric flow rate of gas GAS can be controlled.

[0135] The volumetric flow rate of gas GAS can be controlled such that i) the volumetric flow rate of gas GAS injected into the heating funnel 10 decreases simultaneously with the decrease in the pressure difference PIO between the inside and outside of the heating funnel 10, which is used to offset the pressure loss due to the ejection of the first material M1, or

[0136] The volumetric flow rate of gas GAS is controlled such that, as the first material M1 is ejected, the reduction in the weight of the first material M1 and the reduction in pressure loss acting on the flow of the first material M1 with opposite tendencies are offset, while the pressure difference between the inside and outside of the heating funnel 10 is kept constant, and the volumetric flow rate of gas GAS injected into the heating funnel 10 is kept constant.

[0137] Hereinafter, a more detailed description will be given of one aspect of a multiphase 3D printing apparatus according to an embodiment of the present invention.

[0138] In a multiphase 3D printing apparatus according to an embodiment of the present invention, a liquid first material M1 for forming the model itself can be ejected from the heating funnel 10 to the worktable S according to the pressure difference PI0 between the inside and outside of the heating funnel 10. According to the pressure difference PI0 between the inside and outside of the heating funnel 10, a positive pressure difference can cause an extrusion force that can force the liquid second material M2 filling the inside of the heating funnel 10 to be squeezed out of the heating funnel 10, and a negative pressure difference can cause an attraction force that attracts the first material M1 toward the outside of the heating funnel 10 and pulls it into the inside of the heating funnel 10. As will be described later, according to one embodiment of the present invention, for the first material M1 molten in the heating funnel 10, the inner diameter of the heating funnel 10 gradually decreases from the inside due to the weight of the first material M1 itself, forming a bottleneck portion BN with the smallest inner diameter connected to the first nozzle 10a, thus restricting the flow of the liquid first material M1. Furthermore, since the circumferential surface of the heating funnel 10, which is formed as described above with a wider top and narrower bottom shape, may cause flow friction on the flow of the liquid first material M1, this is due to the bottleneck portion BN of the heating funnel 10 and the circumferential surface of the heating funnel 10. The flow resistance caused by flow friction on the surface can provide an appropriate extrusion force to force the flow of the first material M1 to continue flowing from the heating funnel 10 toward the first nozzle 10a against such flow resistance. For example, according to one embodiment of the present invention, for the purpose of shortening the cycle time in the molding process, the pressure difference PIO between the inside and outside of the heating funnel 10 containing the first material M1 can be set to positive pressure as an extrusion force for the flow of the first material M1, together with the weight of the first material M1.

[0139] In other words, according to one embodiment of the present invention, in order to shorten the cycle time required to form a model, the flow rate of the liquid first material M1 from the heating funnel 10 toward the worktable S or the ejection rate of the liquid first material M1 ejected from the first nozzle 10a onto the worktable S can be maintained at an appropriate or higher level, and the pressure difference PIO between the inside and outside of the heating funnel 10, which can be acted by the extrusion force of the first material M1 from the heating funnel 10 toward the worktable S, can be set to a positive pressure, so that the flow rate of the first material M1 or the ejection rate of the first material M1 can be maintained at a level at least higher than the appropriate level of the flow rate of the first material M1 from the heating funnel 10 toward the worktable S or the ejection rate of the first material M1 ejected from the first nozzle 10a due to the weight of the first material M1. For example, according to one embodiment of the present invention, in order to shorten the cycle time in the molding process of the shaped object, the flow or ejection speed of the first material M1 from the heating funnel 10 toward the worktable S can be increased, and the conveying speed of the first nozzle 10a that ejects the first material M1 can be increased to correspond to the increased flow or ejection speed of the first material M1. Furthermore, by increasing the conveying speed of the first nozzle 10a that scans the area (shaped area) where the shaped object is formed, in other words, by increasing the coating volume V of the first material M1 per unit time that forms the shaped object itself, the cycle time required to form the shaped object or the cycle time for filling the set volume of the shaped object can be shortened.

[0140] According to one embodiment of the present invention, the inner diameter of the heating funnel 10 that ejects the first material M1 gradually decreases from the upper inlet where the raw material of the solid metal block, i.e., the liquid first material M1, is fed in to the bottleneck portion BN connected to the lower end of the first nozzle 10a. At the bottleneck portion BN connected to the first nozzle 10a, the minimum inner diameter can be formed while a flow resistance is formed to limit the volumetric flow rate of the first material M1 molten inside the heating funnel 10. In order to increase the volumetric flow rate of the first material M1 to an appropriate level (e.g., for the purpose of shortening the cycle time) without the pressure loss caused by this flow resistance, according to one embodiment of the present invention, the pressure difference PIO between the inside and outside of the heating funnel 10 containing the first material M1 can be controlled bidirectionally by positive / negative pressure. Thus, the flow or ejection velocity of the first material M1 can be increased on top of the weight of the first material M1, rather than depending on the weight of the first material M1, while providing control parameters for the flow or ejection velocity of the first material M1.

[0141] In this specification, the pressure difference PIO between the inside and outside of the heating funnel 10 can be based on the pressure on the worktable S forming the outside of the heating funnel 10, i.e., the external pressure PO of the heating funnel 10, or the atmospheric pressure (1 atm) in the atmospheric environment forming the outside of the heating funnel 10, meaning the relative pressure accumulated inside the heating funnel 10 (the internal pressure PI of the heating funnel 10 relative to the external atmospheric pressure of the heating funnel 10). In this sense, according to an embodiment of the invention, the pressure difference PIO between the inside and outside of the heating funnel 10 can be equivalent to the internal pressure PI of the heating funnel 10 relative to the external atmospheric pressure (1 atm) of the heating funnel 10. Furthermore, the liquid first material M1 contained in the heating funnel 10 can act as a squeezing force to accelerate the flow from the inside of the heating funnel 10 toward the worktable S to the outside, or an attractive force to decelerate or brake the flow from the inside of the heating funnel 10 toward the worktable S to the outside.

[0142] According to one embodiment of the present invention, the inner diameter of the heating funnel 10 that supplies liquid first material M1 to the worktable S through the first nozzle 10a gradually decreases from the upper inlet where the raw material of the solid metal block, i.e. the liquid first material M1, is fed down to the lower first nozzle 10a and forms a bottleneck portion BN, which forms the smallest inner diameter. Furthermore, the heating funnel 10 can be formed into a funnel shape including a circumferential surface with its inner diameter reduced.

[0143] According to one embodiment of the present invention, the flow of the liquid first material M1 from the heating funnel 10 toward the worktable S can be controlled based on the pressure difference PIO between the inside and outside of the heating funnel 10. This control can be based on the pressure difference PIO between the inside and outside of the heating funnel 10, taking into account pressure losses caused by the bottleneck portion BN of the heating funnel 10 (which can act as flow resistance to the flow from the inside of the heating funnel 10 toward the worktable S) and flow friction acting on the circumferential surface of the heating funnel 10 with its narrowed inner diameter, for example, by subtracting the aforementioned pressure losses. For example, the liquid first material M1 molten inside the heating funnel 10 can form a flow that is ejected from the first heating funnel 10 toward the worktable S. Such a flow of the first material M1 can be accelerated or decelerated based on the pressure difference PIO between the inside and outside of the heating funnel 10. According to one embodiment of the present invention, the flow of the first material M1 can also be braked based on the pressure difference PIO between the inside and outside of the heating funnel 10.

[0144] According to one embodiment of the present invention, the pressure difference PIO between the inside and outside of the heating funnel 10 can be calculated based on the external pressure PO (atmospheric pressure, 1 atm) of the heating funnel 10. This internal pressure PI of the heating funnel 10 can be obtained by subtracting the external pressure PO (atmospheric pressure, 1 atm) from the external pressure PO. In this case, the pressure difference PIO between the inside and outside of the heating funnel 10 can be controlled bidirectionally for both positive and negative pressure. More specifically, based on the internal pressure PI of the heating funnel 10 fluidly connected to the bidirectional pressure control unit 100, the internal pressure PI of the heating funnel 10 is set to be higher than the external pressure PO, and the pressure difference PIO between the inside and outside of the heating funnel 10 is used to determine the internal pressure. The positive pressure of the pressure difference PIO between the inside and outside of the heating funnel 10 accelerates the flow of the liquid first material M1 contained in the heating funnel 10 to increase the flow rate. Alternatively, according to the internal pressure of the heating funnel 10 fluidly connected to the bidirectional pressure control unit 100, the internal pressure PI of the heating funnel 10 is formed to be lower than the external pressure PO of the heating funnel 10, and the negative pressure of the pressure difference PIO between the inside and outside of the heating funnel 10 slows down the flow rate of the first material M1 contained in the heating funnel 10 or makes the flow rate of the first material M1 substantially zero or negative while braking the flow of the first material M1.

[0145] According to one embodiment of the present invention, the internal pressure PI of the heating funnel 10 can be increased or decreased by a bidirectional pressure control unit 100 fluidly connected to the heating funnel 10. This allows the internal pressure PI of the heating funnel 10 to be set to positive or negative based on atmospheric pressure, which is the external pressure PO of the heating funnel 10. More specifically, under the control of the bidirectional pressure control unit 100, the internal pressure PI of the heating funnel 10 can be increased or decreased simultaneously with the injection or discharge of gaseous gas accumulated in the heating funnel 10 and forming the internal pressure PI. The internal pressure PI can be increased or decreased based on the internal pressure PI of the heating funnel 10 or the external pressure PO of the heating funnel 10 at constant atmospheric pressure. The pressure difference PIO between the inside and outside of the heating funnel 10 can accelerate or decelerate the flow of the first material M1 molten inside the heating funnel 10 to increase or decrease the flow rate. For example, a positive pressure can be formed between the inside and outside of the heating funnel 10 by introducing gas GAS into the heating funnel 10 to accumulate it and form an internal pressure, thereby accelerating the flow of the first material M1 discharged from the inside of the heating funnel 10 to the outside. Conversely, a negative pressure difference can also be formed between the inside and outside of the heating funnel 10 by discharging gas GAS from the heating funnel 10, which forms an internal pressure PI due to the gas GAS accumulated inside the heating funnel 10, thereby decelerating the flow of the first material M1 discharged from the inside of the heating funnel 10 to the outside.

[0146] According to one embodiment of the present invention, since the heating funnel 10 filled with a certain amount of first material M1 sprays the first material M1 onto the worktable S outside the heating funnel 10, while the amount of first material M1 filling the first heating funnel 10 decreases over time, gas GAS can be injected into the heating funnel 10 to fill the space in the heating funnel 10 that was previously occupied by the first material M1. Even if gas GAS is injected into the heating funnel 10 from the bidirectional pressure control unit 100, within the limit of filling the space inside the heating funnel 10 formed by the spraying of the first material M1, the injection of gas GAS into the heating funnel 10 will not cause gas GAS accumulation inside the heating funnel 10 or generate an increase in the internal pressure PI of the heating funnel 10 due to gas GAS accumulation or an acceleration of the flow of the first material M1 metal due to the increase in the internal pressure PI of the heating funnel 10.

[0147] According to an embodiment of the present invention, the pressure difference PIO between the inside and outside of the heating funnel 10 can accelerate the flow of the first material M1 from the inside of the heating funnel 10 toward the worktable S outside the heating funnel 10 (e.g., increase the flow rate), and the gas GAS injection toward the heating funnel 10 for accelerating the flow can induce an increase in the internal pressure PI through the accumulation of gas GAS inside the heating funnel 10. According to one embodiment of the present invention, the internal pressure PI of the heating funnel 10 can be formed by the accumulation of gaseous gas (GAS) and substances such as the first material M1 inside the heating funnel 10. According to one embodiment of the present invention, in a driving environment where the first material M1 is ejected from the heating funnel 10 and the fluid flows out from the heating funnel 10 toward the external worktable S, more specifically, in a driving environment where the heating funnel 10 is filled with a limited capacity to achieve the ejection of the first material M1, the accumulation of substances filling the interior of the heating funnel 10 may not be achieved if the amount of gaseous gas (GAS) is only replenished with the amount of the first material M1 discharged from the heating funnel 10. Therefore, for example, the injection of gaseous gas into the heating funnel 10 will not cause an increase in the internal pressure PI of the heating funnel 10 due to the accumulation of substances. More specifically, when the injection of gas GAS into the heating funnel 10 per unit time is achieved only by the amount of first material M1 ejected from the heating funnel 10 per unit time, for example, while the volume of the substance filling the volume formed inside the heating funnel 10, such as the volume of gas GAS and first material M1, is kept constant, even if gas GAS is injected, the internal pressure PI of the heating funnel 10 will not increase. Therefore, the flow acceleration that increases the flow rate of the metal flow of the first material M1 from inside the heating funnel 10 toward the worktable S outside the heating funnel 10 may not be achieved.

[0148] According to one embodiment of the present invention, since the first material M1 is ejected from the inside of the heating funnel 10 containing a certain amount of the first material M1 toward the worktable S outside the heating funnel 10, in order to fill the space corresponding to the ejected amount of the first material M1, a bidirectional pressure control unit 100 fluidly connected to the heating funnel 10 can supply gas GAS with a volume capable of filling the space after the first material M1 has flowed out to the heating funnel 10. For example, the gas GAS volume flow rate can be provided per unit time for the ejected amount of the first material M1 from the heating funnel 10, so that the gas GAS with a volume capable of filling the volume of the ejected first material M1 can be supplied.

[0149] According to one embodiment of the present invention, a heating funnel 10 filled with a liquid first material M1 may include a bottleneck portion BN connected to a worktable S from which the liquid first material M1 is ejected from the heating funnel 10. The bottleneck portion BN may include a circumferential surface that is wider at the top and narrower at the bottom, with its inner diameter gradually decreasing from the upper inlet port where the first material M1, as a solid metal block, is inserted towards the lower nozzle 10a from which the liquid first material M1 is ejected. The flow of the liquid first material M1 along this circumferential surface may experience flow friction. For example, a boundary layer where the liquid first material M1 stagnates may form on the circumferential surface. The viscosity of this boundary layer and the flow of the first material M1 on the boundary layer, or the cohesive force between the particles forming the first material M1, may cause the first material M1 to flow... The pressure loss is experienced due to flow friction. Simultaneously, the bottleneck section BN, which substantially limits the amount of the first material M1 ejected from the inside of the heating funnel 10 onto the worktable S, also causes pressure loss. To compensate for this pressure loss experienced during the ejection of the liquid first material M1 from the inside of the heating funnel 10 onto the worktable S, the pressure difference PIO between the inside and outside of the heating funnel 10 can be set to a positive pressure. Considering that the pressure obtained by subtracting the pressure loss from the pressure difference PIO between the inside and outside of the heating funnel 10, which is thus set to a positive pressure, can accelerate the flow and increase the flow velocity of the first material M1, the pressure difference PIO between the inside and outside of the heating funnel 10 can be set to a positive pressure exceeding the pressure loss.

[0150] According to one embodiment of the present invention, when the pressure difference PIO between the inside and outside of the heating funnel 10 is set to a level equivalent to the pressure loss fraction, the metal of the first material M1 filling the inside of the heating funnel 10 can be discharged at a constant discharge rate to the worktable T through the first ejection unit while maintaining a constant flow velocity. In other words, when the pressure difference PIO between the inside and outside of the heating funnel 10 is maintained at a level equivalent to the pressure loss fraction, the discharge rate of the liquid first material M1 supplied from the inside of the heating funnel 10 to the worktable S can be kept constant.

[0151] According to one embodiment of the present invention, considering the driving environment of the heating funnel 10, where the amount of liquid first material M1 gradually decreases as it is ejected from the heating funnel 10 containing a limited amount of first material M1 through the first nozzle 10a onto the worktable S, the pressure loss component (or flow resistance) caused by the flow of liquid first material M1 ejected from the heating funnel 10 onto the worktable S can be reduced along the time axis. More specifically, the pressure loss component (or flow resistance) caused by the flow in the heating funnel 10 may include the flow friction component caused by the upper-wide and lower-narrow circumferential surface of the heating funnel 10, whose inner diameter is reduced. As the ejection of the first material M1 causes the amount of first material M1 filling the heating funnel 10 to decrease along the time axis, the contact area formed with the upper-wide and lower-narrow circumferential surface of the heating funnel 10 can gradually decrease. Due to this reduction in the contact area between the first material M1 and the circumferential surface of the heating funnel 10, the flow friction associated with the contact surface of the heating funnel 10 can be reduced, and the pressure loss component (or flow resistance) can also be reduced. According to one embodiment of the present invention, the amount of liquid first material M1 filling the interior of the heating funnel 10, which is filled with a certain amount of first material M1, is reduced due to the ejection of liquid first material M1 from the worktable S facing outward. Consequently, the contact area between the first material M1 and the circumferential surface of the heating funnel 10 filled with the first material M1 can be reduced. As a result of the reduction in contact area, the pressure loss (flow resistance) caused by frictional flow can be reduced.

[0152] According to one embodiment of the present invention, in a steady-state driving environment where the ejection amount of the first material M1 on the worktable S from the inside of the heating funnel 10 toward the outside is kept constant, the ejection amount of the liquid first material M1 or the flow velocity of the liquid first material M1 can be kept constant. Corresponding to the pressure loss component (flow resistance) decreasing along the time axis, the pressure difference PIO between the inside and outside of the heating funnel 10, which forms a positive pressure to offset the pressure loss component, can also be reduced to keep the flow velocity of the liquid first material M1 constant. In other words, considering that the pressure difference PIO between the inside and outside of the heating funnel 10 is the relative internal pressure PI of the heating funnel 10 based on the external pressure PO (atmospheric pressure, 1 atm) of the heating funnel 10 which is kept at a constant atmospheric pressure, the relative internal pressure PI of the heating funnel 10 based on atmospheric pressure can decrease along the time axis. According to various embodiments of the present invention, since the amount of the first material M1 contained inside the heating funnel 10 gradually decreases over time, the reduction in the contact area between the first material M1 and the circumferential surface of the heating funnel 10 that forms frictional flow may lead to a reduction in flow resistance or pressure loss. At the same time, since the weight of the first material M1 decreases corresponding to the decrease in the amount of the first material M1 contained in the heating funnel 10, the reduction in the weight of the first material M1 that promotes the flow of the first material M1 from inside the heating funnel 10 toward the worktable S outside the heating funnel 10 and the reduction in the flow resistance that prevents the flow of the first material M1 from inside the heating funnel 10 toward the worktable S are mutually offset. Therefore, the pressure difference PIO between the inside and outside of the heating funnel 10 used to form the stable state can be maintained at a certain level.

[0153] According to one embodiment of the present invention, a bidirectional pressure control unit 100 is configured to supply gas GAS to the interior of a heating funnel 10 to counteract pressure loss caused by the flow of the first material M1 from the interior of the heating funnel 10 toward the worktable S. For the purpose of counteracting pressure loss, gas GAS can be injected into the heating funnel 10 so that the pressure difference PIO between the interior and exterior of the heating funnel 10 is set to a positive pressure. At the same time, the flow rate of gas GAS injected per unit time can be reduced, for example, the volumetric flow rate of the injected gas GAS, so that the internal pressure of the heating funnel 10 is reduced in accordance with the pressure loss decreasing along the time axis. According to various embodiments of the present invention, since the amount of the first material M1 contained in the heating funnel 10 is reduced, the reduction in the weight of the first material M1 relative to the flow of the first material M1 and the reduction in the flow resistance of the first material M1 are canceled out. As a result, the pressure difference PIO between the inside and outside of the heating funnel 10 for maintaining the flow of the first material M1 in a steady state can be maintained at a certain level. For this purpose, the bidirectional pressure control unit 100 connected to the heating funnel 10 can maintain the flow rate of gas GAS toward the heating funnel 10, such as the volumetric flow rate of injected gas GAS, at a certain level.

[0154] According to one embodiment of the present invention, in a steady-state driving environment where the ejection amount of the first material M1 ejected from the interior of the heating funnel 10 to the external worktable S is kept constant, the volume of the first material M1 injected into the heating funnel 10 per unit time can be kept constant. For example, for the bidirectional pressure control unit 100 fluidly connected to the interior of the heating funnel 10, a gas GAS having a volume corresponding to the volume of the first material M1 ejected from the heating funnel 10 per unit time can be injected into the interior of the heating funnel 10 to fill the space equivalent to the volume ejected from the heating funnel 10 per unit time. Under such control by the bidirectional pressure control unit 100, as a result, the internal pressure PI of the heating funnel 10, which accumulates the same volume of material without changing the volume of material filling the heating funnel 10, can be kept constant. As described above, corresponding to the pressure loss component (flow resistance) caused by the molten metal block injected into the heating funnel 10 and the liquid first material M1 filled with a limited capacity being ejected from the inside of the heating funnel 10 to the external worktable S, and the flow of the first material M1 from the inside of the heating funnel 10 toward the outside, the internal pressure PI of the heating funnel 10 can also be reduced to offset the reduced pressure loss component (flow resistance). Therefore, according to an embodiment of the present invention, the gas flow rate injected into the heating funnel 10 per unit time, for example, the volumetric flow rate equivalent to the volume injected into the heating funnel 10 per unit time, can also be controlled to exhibit a decreasing curve along the time axis.

[0155] According to one embodiment of the present invention, in a driving environment that achieves a steady-state in which a first material M1 is ejected from the inside of the heating funnel 10 towards the outside of the heating funnel 10 at a constant volume per unit time, a bidirectional pressure control unit 100 fluidly connected to the heating funnel 10 can inject gas GAS into the heating funnel 10 at a constant volumetric flow rate according to the constant volume of the first material M1 flowing out per unit time. Since the material is filled with a certain volume, the internal pressure PI of the heating funnel 10 can be maintained constant. According to one embodiment of the present invention, the internal pressure PI of the heating funnel 10 can correspond to a decrease along the time axis to a decrease in pressure loss along the time axis. For this purpose, the flow rate of gas GAS injected into the heating funnel 10 per unit time, for example, the volumetric flow rate of gas GAS equivalent to the volume injected into the heating funnel 10 per unit time, can decrease along the time axis.

[0156] According to various embodiments of the present invention, as the amount of the first material M1 contained in the heating funnel 10 decreases, the decrease in the weight of the first material M1 acting in the opposite direction to the flow of the first material M1 is offset by the decrease in the flow of the first material M1, and the pressure difference PIO between the inside and outside of the heating funnel 10 can be kept constant to form a steady state of flow of the first material M1, and the flow rate of gas GAS supplied to the inside of the heating funnel 10, such as the volume of gas GAS supplied to the inside of the heating funnel 10 per unit time, can be kept constant.

[0157] According to one embodiment of the present invention, a bidirectional pressure control unit 100 connected to the heating funnel 10 and used to heat the internal pressure PI of the heating funnel 10 can control the internal pressure PI of the heating funnel 10 or the pressure difference PIO between the inside and outside of the heating funnel 10 by injecting or discharging gas GAS that accumulates inside the heating funnel 10 and forms the internal pressure PI. At this time, the gas GAS injected and discharged under the control of the bidirectional pressure control unit 100 can be either compressible gas GAS or incompressible gas GAS (Mach number 0.3 or less). For example, according to one embodiment of the present invention, as the gas GAS flowing out and in controlled by the bidirectional pressure control unit 100, the density of the compressible gas GAS can be changed according to the pressure. For example, according to one embodiment of the present invention, the volumetric flow rate of the gas GAS injected into the heating funnel 10 can be reduced along the time axis so that the internal pressure of the heating funnel 10 corresponds to the pressure loss (flow resistance) that decreases along the time axis. The volumetric flow rate of the gas GAS injected per unit time thus decreasing along the time axis can be understood as assuming that the gas GAS is incompressible, that is, the volume of the gas GAS injected per unit time is kept constant along the time axis, and its density does not change with the change of the internal pressure PI of the heating funnel 10. Furthermore, according to various embodiments of the present invention, in response to the decrease in the amount of the first material M1 contained in the heating funnel 10 over time, the decrease in pressure loss or flow resistance that tends to act on the flow of the first material M1 and the decrease in the weight of the first material M1 are offset against each other. As the gas GAS injected and discharged by the bidirectional pressure air unit 100, the incompressible gas GAS can be supplied to the heating funnel 10 at a certain gas GAS flow rate or a certain volume of gas GAS per unit time.

[0158] According to various embodiments of the present invention, the gas gas gas (GAS) whose outflow and inflow to the heating funnel 10 is controlled by the bidirectional pressure control unit 100 and used to control the internal pressure PI of the heating funnel 10 may include various compressible gas ...

[0159] According to various embodiments of the present invention, the gas GAS flowing out of and into the heating funnel 10, controlled by a bidirectional pressure control unit 100 connected to the heating funnel 10 to control the internal pressure PI of the heating funnel 10, may include a compressible gas GAS whose density or volume changes according to a given pressure. According to one embodiment of the present invention, in a steady-state driving environment where the ejection rate of the liquid first material M1 is kept constant, in response to a reduction in pressure loss components such as flow friction caused by the ejection of the first material M1 from the upper-wide, lower-narrow circumferential surface of the heating funnel 10, the internal pressure PI of the heating funnel 10 under the control of the bidirectional pressure control unit 100 can be reduced or maintained at a certain level. At this time, the operation of the bidirectional pressure control unit 100 connected to the heating funnel 10 is controlled to reduce or maintain the internal pressure PI of the heating funnel 10 by, for example, an injection rate equivalent to, per unit time... The volumetric flow rate of the gas GAS entering the heating funnel 10 is considered based on the characteristics of the density or volume change of the compressible gas GAS. According to the density increase and volume compression of the compressible gas GAS under the pressure of the heating funnel 10, it is considered that compared with the incompressible gas GAS, it exhibits a relatively small slow gradient reduction rate compared with the reduction rate of the volumetric flow rate equivalent to the volume injected into the heating funnel 10 per unit time, or the density or volume change of the compressible gas GAS filling the space caused by the ejection of the incompressible first material M1. The characteristics of the gas GAS density or volume change follow the curve of the gas GAS volumetric flow rate increasing along the time axis.

[0160] In summary, regarding the pressure loss caused by the flow resistance or flow friction of the liquid first material M1 ejected from the inside of the heating funnel 10 onto the worktable S, considering the reduction in the contact area between the first material M1 filled in the heating funnel 10 (which is wider at the top and narrower at the bottom) and the circumferential surface of the heating funnel 10 filled with the first material M1 (which has a certain limited capacity), the pressure loss can gradually decrease along the time axis. At this time, under a steady-state driving environment where the ejection amount of the second material M2 from the inside of the heating funnel 10 onto the worktable S is kept constant, the internal pressure PI of the heating funnel 10 can also decrease along the time axis to offset the decrease in pressure loss along the time axis and maintain a constant flow rate of the first material M1. Alternatively, considering the reduction in pressure loss or flow resistance corresponding to the decrease in the capacity of the first material M1 over time, and the offsetting effect of the weight of the first material M1, the internal pressure PI of the heating funnel 10 can be maintained at a certain level along the time axis.

[0161] According to various embodiments of the present invention, the activity of the bidirectional pressure control unit 100 fluidly connected to the heating funnel 10 can be controlled to achieve a steady-state driving environment as described above, i.e., following the change curve of the internal pressure PI of the heating funnel 10, which decreases or is maintained along the time axis. More specifically, the bidirectional pressure control unit 100 can control the flow rate of gas GAS injected into the heating funnel 10 to control the internal pressure PI of the heating funnel 10, and, according to the bidirectional pressure control unit 100, the volumetric flow rate of gas GAS, equivalent to the volume injected into the heating funnel 10 per unit time, can increase or decrease along the time axis, depending on the compressibility of the gas GAS injected into the heating funnel 10. For example, according to one embodiment of the present invention, when the gas GAS or fluid injected into the heating funnel 10 is compressible gas GAS, the relative ratio of the substances filling the heating funnel 10 to replenish the blanks of the second material M2 flowing out of the heating funnel 10 per unit time under a stable driving environment can vary depending on the ratio of a relatively high ratio of incompressible substance (second material M2) to a low ratio of compressible substance (compressible gas GAS) and a relatively low ratio of incompressible substance (second material M2) to a high ratio of compressible substance (compressible gas GAS). At the same time, the flow rate of GAS when the high ratio of compressible substance (compressible gas GAS) gradually occupies the pressure of gas GAS that is not compressed to the same level as the interface of the second material M2 or when the compression is insufficient, for example, the gas flow rate of compressible gas GAS per unit time volume, can be increased. However, regarding the gas flow rate of the compressible gas GAS injected into the heating funnel 10, the flow rate can be measured at the volume flow rate measurement point, for example, at the measurement point where the internal pressure PI of the heating funnel 10 can be transmitted, under the condition that the compressible gas GAS is substantially compressed due to the internal pressure PI of the heating funnel 10. Therefore, more generally, the volume flow rate of the compressible gas GAS can be understood as decreasing or remaining constant along the time axis.

[0162] According to one embodiment of the present invention, if the gas GAS or fluid injected into the heating funnel 10 is incompressible or can be considered incompressible, for such incompressible gas GAS (or fluid), the incompressible substances including the first material M1 and the incompressible GAS can accumulate inside the heating funnel 10 and form the internal pressure PI of the heating funnel 10, regardless of the change in the relative ratio between the first material M1 and the gas GAS along the time axis. Therefore, the volumetric flow rate of the incompressible gas GAS can decrease or remain constant along the time axis.

[0163] According to one embodiment of the present invention, the bidirectional pressure control unit 100 may include

[0164] A first fluid conduit 110 extends from the common confluence location COM toward the heating funnel 10;

[0165] A second fluid conduit 120, which connects from the common confluence location COM to the positive pressure source PS; and

[0166] The third fluid line 130 is connected from the common confluence location COM to the negative pressure source NS.

[0167] According to one embodiment of the present invention, the bidirectional pressure control unit 100 may include,

[0168] A first fluid valve 111 is connected on the first fluid pipe 110 between the common confluence position COM and the heating funnel 10;

[0169] A second fluid valve 121 is connected on the second fluid pipe 120 between the common confluence location COM and the positive pressure source PS; and

[0170] A third fluid valve 131 is connected on the third fluid pipe 130 between the common confluence position COM and the negative pressure source NS.

[0171] According to one embodiment of the present invention, the bidirectional pressure control unit 100 can

[0172] Valve controller 150 is connected to each of the first to third fluid valves 111, 121, 131 and applies control signals to the first to third fluid valves 111, 121, 131 to control the opening and closing of the valves and the degree of valve opening.

[0173] According to one embodiment of the present invention, the valve controller 150 can

[0174] The first and second fluid valves 111 and 121 are opened to set the pressure difference PIO between the inside and outside of the heating funnel 10 to a positive pressure, and

[0175] The first and third fluid valves 111 and 131 can be controlled to open to set the pressure difference PI0 between the inside and outside of the heating funnel 10 to a negative pressure.

[0176] According to one embodiment of the present invention, the valve controller 150 can

[0177] The first to third fluid valves 111, 121, and 131 are controlled to alternately open and close the second and third fluid valves 121 and 131, respectively connected to the positive pressure source PS and the negative pressure source NS, while the first fluid valve 111 is open, so that the pressure difference PIO between the inside and outside of the heating funnel 10 alternately reverses between positive and negative pressure.

[0178] For example, the valve controller 150

[0179] The opening / closing of the second fluid valve 121 connected to the positive pressure source PS and the opening / closing of the third fluid valve 131 connected to the negative pressure source NS can be controlled inconsistently with each other.

[0180] According to one embodiment of the present invention, the bidirectional pressure control unit 100 may include

[0181] A first pressure gauge 115 is connected on the first fluid tube 110 between the heating funnel 10 and the first fluid valve 111;

[0182] A second pressure gauge 125 is connected on the second fluid line 120 between the positive pressure source PS and the second fluid valve 121; and

[0183] A third pressure gauge 135 is connected on the third fluid line 130 between the negative pressure source NS and the third fluid valve 131.

[0184] According to one embodiment of the present invention, the first pressure gauge 115 can measure the internal pressure PI of the heating funnel 10.

[0185] The second pressure gauge 125 and the third pressure gauge 135 can measure the pressure of the positive pressure source PS and the negative pressure source NS, respectively.

[0186] A multiphase 3D printing apparatus according to an embodiment of the present invention may include a control unit 151, which is configured as follows:

[0187] The coating volume V per unit time is calculated based on the width w of the scan line SL that forms the transfer path of the first nozzle 10a and the scan speed per unit time, which is equivalent to the transfer speed.

[0188] Based on the calculated coating volume V per unit time, the pressure difference PIO between the inside and outside of the heating funnel 10 is set to a positive pressure to accelerate the flow of the liquid first material M1, or the pressure difference PIO between the inside and outside of the heating funnel 10 is set to a positive pressure to decelerate or brake the flow of the liquid first material M1.

[0189] The valve controller 150 can control the opening and closing of the first to third fluid valves 111, 121, and 131, and their opening degree, so that the internal pressure PI value measured by the first pressure gauge 115 follows the pressure difference PIO between the inside and outside of the heating funnel 10, which is set to positive or negative pressure by the control unit 151.

[0190] Hereinafter, one aspect of a multiphase 3D printing apparatus according to an embodiment of the present invention will be described.

[0191] According to one embodiment of the present invention, the bidirectional pressure control unit 100 fluidly connected to the heating funnel 10 can be configured as having three branches (corresponding to the first to third fluid pipes 110, 120, and 130): a branch connected to a positive pressure source PS to form a positive pressure on the pressure difference PIO between the inside and outside of the heating funnel 10 (corresponding to the second fluid pipe 120); a branch connected to a negative pressure source NS to form a negative pressure on the pressure difference PIO between the inside and outside of the heating funnel 10 (corresponding to the third fluid pipe 130); and a branch extending from the common confluence position COM of the positive pressure source PS and the negative pressure source NS toward the heating funnel 10 (corresponding to the first fluid pipe), which are connected to each other at the common confluence position COM. More specifically, it may include a first fluid pipe 110 extending from the common confluence position COM toward the heating funnel 10, a second fluid pipe 120 extending from the common confluence position COM toward the positive pressure source PS, and a third fluid pipe 130 extending from the common confluence position COM toward the negative pressure source NS.

[0192] According to one embodiment of the present invention, the bidirectional pressure control unit 100 can provide positive pressure to the heating funnel 10 by opening the second fluid pipe 120 connected to the positive pressure source PS or by controlling the opening degree of the already opened second fluid pipe 120 and by the first fluid pipe 110 connected to the second fluid pipe 120 via the common confluence position COM. Conversely, the bidirectional pressure control unit 100 can provide negative pressure to the heating funnel 10 by opening the third fluid pipe 130 connected to the negative pressure source NS or by controlling the opening degree of the already opened third fluid pipe 130 and by the first fluid pipe 110 connected to the third fluid pipe 130 via the common confluence position COM.

[0193] According to one embodiment of the present invention, providing positive pressure to the heating funnel 10 can refer to forming a positive pressure between the inside and outside of the heating funnel 10 (for example, the internal pressure PI of the heating funnel 10 > the external pressure PO of the heating funnel 10) to accelerate the flow velocity of the liquid first material M1 ejected from the inside of the heating funnel 10 to the outside of the worktable S, or to drive the constant velocity flow or steady-state formed by subtracting the pressure loss caused by the flow of the first material M1 from the pressure difference PIO (positive pressure) between the inside and outside of the heating funnel 10.

[0194] According to one embodiment of the present invention, providing negative pressure to the heating funnel 10 can refer to creating a negative pressure between the inside and outside of the heating funnel 10 (e.g., the internal pressure PI of the heating funnel 10 < the external pressure PO of the heating funnel 10) to decelerate the flow velocity of the liquid first material M1 flowing from the inside of the heating funnel 10 to the worktable S outside. For example, according to one embodiment of the present invention, the flow of the liquid first material M1 discharged from the inside of the heating funnel 10 to the worktable S outside can be braked (e.g., the flow velocity can be made substantially zero or negative - a negative flow velocity of the first material M1 flowing from the first nozzle 10a toward the inside of the heating funnel 10). For example, it can provide deceleration of the flow velocity of the first material M1 obtained from a previous positive pressure. For example, the flow of the first material M1 can be stopped, or a negative flow velocity can be provided to the flow of the first material M1 to reverse the flow direction so that the metallic flow of the first material M1 is in a negative direction, i.e., from the first nozzle toward the heating funnel 10. According to one embodiment of the present invention, the bidirectional pressure control unit 100 can provide a compressive force from the inside of the heating funnel 10 toward the outside of the worktable S by positive pressure, or brake the flow from the inside of the heating funnel 10 toward the outside of the worktable S, or provide an attractive force for the reverse flow from the outside of the worktable S toward the inside of the heating funnel 10.

[0195] According to one embodiment of the present invention, the bidirectional control unit 100 may include a first fluid valve 111 connected between the common confluence position COM and the heating funnel 10, a second fluid valve 121 connected between the common confluence position COM and the positive pressure source PS, and a third fluid valve 131 connected between the common confluence position COM and the negative pressure source NS. Furthermore, it may include a valve controller 150 connected to the first to third fluid valves 111, 121, and 131 and used to apply control signals to each of the first to third fluid valves 111, 121, and 131 to control the opening and closing of the valves and the valve angle. For example, according to one embodiment of the present invention, the valve controller 150 may control the first fluid valve 111 and the second fluid valve 121 to open to set the pressure difference PIO between the inside and outside of the heating funnel 10 to a positive pressure, and control the first fluid valve 111 and the third fluid valve 131 to open to set the pressure difference PIO between the inside and outside of the heating funnel 10 to a negative pressure. For example, according to one embodiment of the present invention, the valve controller 150 can control the first to third fluid valves 111, 121, and 131 to alternately reverse the pressure difference PIO between the inside and outside of the heating funnel 10 between positive and negative pressure, and alternately open and close the second fluid valve 121 and the third fluid valve 131, respectively connected to the positive pressure source PS and the negative pressure source NS, while the first fluid valve 111 is open. More specifically, the valve controller 150 can control the opening / closing of the second fluid valve 121 connected to the positive pressure source PS and the opening / closing of the third fluid valve 131 connected to the negative pressure source NS to be inconsistent with each other.

[0196] According to one embodiment of the present invention, the bidirectional pressure control unit 100 may include a fluid machine configured to output a mechanical pressure difference from an electrical input as a positive pressure source PS and a negative pressure source NS, and includes a low-pressure side inlet and a high-pressure side outlet. For example, according to one embodiment of the present invention, the positive pressure source PS connected to the second fluid pipe 120 of the bidirectional pressure control unit 100 may include a compressor for injecting gas GAS at high pressure into the heating funnel 10 through the high-pressure side outlet, and the negative pressure source NS connected to the third fluid pipe 130 of the bidirectional pressure control unit 100 may include a vacuum pump for discharging gas GAS at low pressure from the heating funnel 10 through the low-pressure side inlet. According to various embodiments of the present invention, the positive pressure source PS connected to the second fluid pipe 120 may include a high-pressure storage tank configured to have a pressure higher than the internal pressure PI of the heating funnel 10 and to inject gas GAS into the heating funnel 10 at high pressure according to the opening and closing of a second fluid valve 121 for connecting the second fluid pipe 120. Furthermore, the negative pressure source NS connected to the third fluid pipe 130 may include a low-pressure storage tank configured to have a pressure lower than the internal pressure PI of the heating funnel 10 and to discharge gas GAS from the heating funnel 10 at low pressure according to the opening and closing of a third fluid valve 131 for connecting the third fluid pipe 130.

[0197] According to one embodiment of the present invention, the bidirectional pressure control unit 100 can set the pressure difference PIO between the inside and outside of the heating funnel 10 to a positive pressure based on the opening of the second fluid valve 121 for connecting the tubing to the second fluid pipe 120 of the positive pressure source PS, and can set the pressure difference PIO between the inside and outside of the heating funnel 10 to a negative pressure based on the opening of the third fluid valve 131 for connecting the tubing to the third fluid pipe 130 of the negative pressure source NS. More specifically, in the control of the bidirectional pressure control unit 100 used to set the pressure difference between the inside and outside of the heating funnel 10 to a positive or negative pressure, the tube bundle of the second fluid tube 120 connected to the positive pressure source PS and the tube bundle of the third fluid tube 130 connected to the negative pressure source NS can be controlled to be inconsistent with each other. For example, in the control of the bidirectional pressure control unit 100 used to set the pressure difference PIO between the inside and outside of the heating funnel 10 to a positive pressure, the blocking of the third fluid tube 130 connected to the negative pressure source NS (blocking of the third fluid tube 131) can be achieved simultaneously with the connection of the second fluid tube 120 connected to the positive pressure source PS (opening of the second fluid valve 121). Conversely, in the control of the bidirectional pressure control unit 100 used to set the pressure difference PIO between the inside and outside of the heating funnel 10 to a negative pressure, the blocking of the second fluid tube 120 connected to the positive pressure source PS (blocking of the second fluid valve 121) can be achieved simultaneously with the connection of the third fluid tube 130 connected to the negative pressure source NS (opening of the third fluid valve). Furthermore, in order for the bidirectional pressure control unit 100 to set the pressure of the heating funnel 10, that is, to control the use of positive pressure by setting the pressure difference PIO between the inside and outside of the heating funnel 100 to positive pressure and to control the use of negative pressure by setting the pressure difference PIO between the inside and outside of the heating funnel 100 to negative pressure, pressure transmission from the positive pressure source PS and the negative pressure source NS to the heating funnel 10 can be achieved through the connection of the first fluid pipe 110. More specifically, in the control of using positive pressure by setting the pressure difference PIO between the inside and outside of the heating funnel 100 to positive pressure, fluid connection between the positive pressure source PS and the heating funnel 10 can be achieved through the connection of the second fluid pipe 120 connected to the positive pressure source PS and the connection of the first fluid pipe 110. For this purpose, the first fluid valve 111 of the first fluid pipe 110 and the second fluid valve 121 of the second fluid pipe 120 can both be opened. On the other hand, in the control of using negative pressure, the pressure difference PIO between the inside and outside of the heating funnel 10 is set to negative pressure. The fluid connection between the negative pressure source NS and the heating funnel 10 can be achieved by connecting the third fluid pipe 130 connected to the negative pressure source NS and the first fluid pipe 110. For this purpose, the first fluid pipe 111 of the first fluid pipe 110 and the third fluid valve 131 of the third fluid pipe 130 can both be opened.That is, according to one embodiment of the present invention, there is a need for precise control of the flow of the first material M1, so as to precisely control the flow of the first material M1 from the heating funnel 10 toward the worktable S, for example, to accurately fill the coating volume V per unit time, which is based on the transport path of the first nozzle 10 for ejecting the flow of the first material M1 (e.g., the width w of the scan line SL forming the transport path) and the transport speed (e.g., the coating volume V per unit time set by the length L of the scan line SL per unit time corresponding to the transport speed). For this purpose, according to one embodiment of the present invention, the bidirectional pressure control unit 100 can alternately reverse the pressure difference PIO between the inside and outside of the heating funnel 10 between positive and negative pressure. At this time, the valve controller 150 for controlling the opening and closing of the first to third fluid valves 111, 121, 131 can control the opening and closing of the first to third fluid valves 111, 121, 131. The connection of the first fluid pipe 110 is achieved by opening the first fluid valve 111, which controls the connection of the first fluid valve 110 to the second fluid pipe 120 connected to the positive pressure source PS, and the second fluid valve 121, which controls the connection of the second fluid pipe 120 connected to the positive pressure source PS, and the third fluid valve 131, which controls the connection of the third fluid valve 131 connected to the negative pressure source NS, are opened and closed alternately in reverse order, so that the pressure difference PIO between the inside and outside of the heating funnel 10 alternately reverses between positive and negative pressure. For example, according to one embodiment of the present invention, the valve controller 150 for controlling the opening and closing of the first to third fluid valves 111, 121, 131 can control the opening and closing of the first to third fluid valves 111, 121, 131 so that the opening and closing of the second and third fluid valves 121, 131 are repeated alternately with the opening of the first fluid valve 111, so that the pressure difference PIO between the inside and outside of the heating funnel 10 alternately reverses between positive and negative pressure.

[0198] According to one embodiment of the present invention, the bidirectional pressure control unit 100 may include a first pressure gauge 115 connected between the heating funnel 10 and the first fluid valve 111, a second pressure gauge 125 connected between the positive pressure source PS and the second fluid valve 121, and a third pressure gauge 135 connected between the negative pressure source NS and the third fluid valve 131. In the bidirectional pressure control unit 100, the first to third pressure gauges 135 can respectively measure the internal pressure PI of the heating funnel 10, the pressure of the positive pressure source PS, and the pressure of the negative pressure source NS. For example, based on the locking of the first to third fluid valves 111, 121, and 131 adjacent to the first to third pressure gauges 135, for example, based on the locking of the first fluid valve 111, the first pressure gauge 115 can measure the internal pressure PI of the heating funnel 10; based on the locking of the second fluid valve 121, the second pressure gauge 125 can measure the pressure of the positive pressure source PS; and based on the locking of the third fluid valve 131, the third pressure gauge 135 can measure the pressure of the negative pressure source.

[0199] For example, according to one embodiment of the present invention, the first pressure gauge 115 is connected to the heating funnel 10 and the first fluid valve 111 on the first fluid pipe 110 and measures the internal pressure PI of the heating funnel 10 (e.g., the first fluid valve 111 is closed) or the flow pressure of gas GAS on the first fluid pipe 110 (e.g., the first fluid valve is open) based on the opening and closing of the first fluid valve 111. Considering that the flow rate of gas GAS is limited, the first pressure gauge 115 can be understood as measuring the internal pressure PI of the heating funnel 10. The second pressure gauge 125 is connected to the positive pressure source PS and the second fluid valve 121 on the second fluid pipe 120 and measures the pressure of the positive pressure source PS (e.g., the second fluid valve 121 is closed) or the pressure of the second fluid pipe 120 based on the opening and closing of the second fluid valve 121. The second pressure gauge 125 can be understood as measuring the pressure of the positive pressure source PS or the pressure of the gas GAS supplied by the positive pressure source PS, taking into account that the flow rate of the gas GAS is finite. The third pressure gauge 135 is connected on the third fluid line 130 between the negative pressure source NS and the third fluid valve 131 and measures the pressure of the negative pressure source NS (e.g., the closing of the third fluid valve 131) or the flow pressure of the gas GAS on the third fluid line 130 (e.g., the opening of the third fluid valve 131) according to the opening and closing of the third fluid valve 131. Taking into account that the flow rate of the gas GAS is finite, the third pressure gauge 135 can be understood as measuring the pressure of the negative pressure source NS or the pressure of the gas GAS discharged from the negative pressure source NS.

[0200] According to one embodiment of the present invention, the pressure difference PIO between the inside and outside of the heating funnel 10 can be determined based on the internal pressure PI of the heating funnel 10 measured by the first pressure gauge 115 or the external atmospheric pressure (1 atm). The volume of gas GAS injected into the heating funnel 10 per unit time can then be calculated to correctly fill the first material based on the transport path (width w of the scan line SL forming the transport path) and the transport speed (length L of the scan line SL per unit time corresponding to the transport speed) of the first nozzle 10a discharging the first material M1. The coating volume V per unit time of M1, and in order to precisely control the volume of gas GAS injected into the heating funnel 10 per unit time, the opening of the first fluid valve 111 and the second fluid valve 121 can be controlled according to the pressure difference between the first pressure gauge 115 and the second pressure gauge 125 in the range where the pressure difference PIO between the inside and outside of the heating funnel 10 is controlled to be positive. The opening of the first fluid valve 111 and the third fluid valve 131 can also be controlled according to the pressure difference between the first pressure gauge 115 and the third pressure gauge 135 in the range where the pressure difference PIO between the inside and outside of the heating funnel 10 is controlled to be negative.

[0201] According to one embodiment of the present invention, the bidirectional pressure control unit 100 can

[0202] Based on the insufficient coating volume V of the first material M1 per unit time set according to the transfer path and transfer speed of the first nozzle 10a, the pressure difference PIO between the inside and outside of the heating funnel 10 is set to a positive pressure to accelerate the flow of the first material M1 from the heating funnel 10 toward the first nozzle 10a, or

[0203] The pressure difference PIO between the inside and outside of the heating funnel 10 is set to a negative pressure based on the interference of the coating volume V of the second material M2 per unit time set according to the transfer path and transfer speed of the first nozzle 10a, so as to reduce or brake the flow of the first material M1 from the heating funnel 10 toward the first nozzle 10a.

[0204] According to one embodiment of the present invention, the bidirectional pressure control unit 100 can

[0205] Based on the width w of the scan line SL forming the transport path of the first nozzle 10a, the pressure difference PIO between the inside and outside of the heating funnel 10 is set to positive pressure to accelerate the flow of the first material M1 from the heating funnel 10 toward the first nozzle 10a, or...

[0206] Based on the width w of the scan line SL that forms the transfer path of the first nozzle 10a, the pressure difference PIO between the inside and outside of the heating funnel 10 is set to a negative pressure to slow down or brake the flow of the first material M1 from the heating funnel 10 toward the first nozzle 10a, based on the reduction of the width w of the scan line SL.

[0207] For example, the width w of the scan line forming the transfer path of the first nozzle 10a can be set to scan the entire shaping area of ​​the object and not overlap with each other and not open to block voids.

[0208] For example, the bidirectional pressure control unit 100 can

[0209] Based on the conveying speed of the first nozzle 10a or based on the length L of the scan line SL per unit time corresponding to the conveying speed, corresponding to a relatively high conveying speed or a relatively long scan line SL per unit time, the pressure difference PIO between the inside and outside of the heating funnel 10 is set to a positive pressure to accelerate the flow of the first material M1 from the heating funnel 10 toward the first nozzle 10a, or

[0210] The pressure difference PIO between the inside and outside of the heating funnel 10 is set to a negative pressure based on the conveying speed of the first nozzle 10a or the length L of the scan line SL per unit time corresponding to a relatively low conveying speed or a relatively short scan line SL per unit time, so as to slow down or brake the flow of the first material M1 from the heating funnel 10 toward the first nozzle 10a.

[0211] For example, based on the coating volume V of the first material M1 per unit time set according to the transfer path and transfer speed of the first nozzle 10a, the pressure difference PIO between the inside and outside of the heating funnel 10 is set to positive or negative pressure to accelerate or reduce the flow of the first material M1 from the heating funnel 10 toward the first nozzle 10a, or to brake the flow of the first material M1.

[0212] The coating volume of the first material M1 per unit time can be calculated based on the product of the width w of the scan line SL forming the transfer path or the cross-sectional area of ​​the scan line SL including the width w dimension of the scan line SL and the length L of the scan line SL per unit time corresponding to the scan speed.

[0213] Hereinafter, one aspect of a multiphase 3D printing apparatus according to an embodiment of the present invention will be described.

[0214] According to one embodiment of the present invention, the flow (flow speed and flow direction) of the first material M1 from the inside of the heating funnel 10 toward the worktable S to form the object itself can be controlled by a bidirectional pressure control unit 100 that provides positive and negative pressure in opposite directions. Furthermore, the flow of the first material M1 ejected onto the worktable S can be precisely controlled in real time by appropriately controlling the coating volume V per unit time according to the first nozzle 10a that is transferred in a manner that follows a transfer plan including a preset transfer path and transfer speed, so as to prevent over- or under-coating of the preset coating volume V.

[0215] For example, according to one embodiment of the present invention, if the flow of the first material M1 ejected from the first nozzle 10a is insufficient to meet the predetermined transfer plan, a portion of the coating volume V set on the transfer path may be blanked, thereby creating a space in the molded object that is not filled by the first material M1, i.e., a void in the molded object. In contrast, according to one embodiment of the present invention, if the flow of the first material M1 discharged from the first nozzle 10a is excessively sprayed in accordance with a preset transfer plan, an additional interference volume exceeding the coating volume V set on the transfer path may be formed. Therefore, this additional interference volume may form a residual height exceeding the upper limit of the height defined by the filling space surrounded by the first material M1 that forms the outline of the object. This may disrupt the height stability of the second material M2 in ways such as forming a dam for the second material M2 that acts as a dam to restrict the flow of the first material M1 while forming the outline of the object, or form a residual volume exceeding the outline of the object and destroy the refinement of the shape of the object, or cause the trouble of needing to change the coating volume V of subsequent layers after that layer because it exceeds the height of each layer in forming the object.

[0216] According to one embodiment of the present invention, the forming of the sculpted object can be achieved by transferring a second nozzle 20a that sprays out a second material M2 forming the outline of the sculpted object and a first nozzle 10a that sprays out a first material M1 forming the interior of the sculpted object, i.e., the sculpted object itself, formed by a material M1. For example, the transfer plan for the first and second nozzles 10a and 20a used to form the sculpted object may include the following presets: the transfer path and transfer speed of the first nozzle 20a that forms the contour curve of the sculpted object outline; the coating volume V of the first material M1 per unit time set based on the transfer path and transfer speed of the first nozzle 10a; the transfer path and transfer speed of the first nozzle 10a that scans the interior region of the sculpted object outline to form the sculpted object itself as the interior region of the sculpted object outline surrounded by the second material M2; and the coating volume V of the first material M1 per unit time set based on the transfer path and transfer speed of the first nozzle 10a.

[0217] According to one embodiment of the present invention, the coating volume V of the first material M1 per unit time can be set based on the width w of the transport path of the first nozzle 10a from which the first material M1 is ejected or the width w of the scan line SL forming the transport path. For example, even within the same shape contour region, the coating volume V of the second material M2, set according to the width w of each transport path or scan line SL based on a pre-set transport path or scan line SL, can be different. For example, depending on the width w of the transport path or scan line SL, the number of scan lines SL used to form the same width of the shape can be different, and the coating volume V of the first material M1 per unit time can be set differently based on the width of each transport path or scan line SL. For example, the width w of the scan lines SL used to form the same width of the shape can be precisely set so that they do not overlap each other and do not form gaps or isolation between each other, and the coating volume V of the first material M1 can be set along each scan line SL based on the width w of the scan line SL.

[0218] like Figure 15 As shown, the coating volume V of the first material M1 per unit time can be set according to the transport path of the first nozzle 10a or the width w of the scan line SL. For example, the coating volume V of the first material M1 per unit time can be calculated as the product of the length of the scan line SL of the first nozzle 10a per unit time, which is equivalent to the transport speed of the first nozzle 10a ejecting the first material M1, and the width w of the scan line L forming the transport path. For example, according to an embodiment of the present invention, due to the fluidity of the liquid first material M1, the width w of the scan line SL of the first nozzle 10a can be formed to flow from the maximum height formed by the first material M1 to both sides. The cross-sectional shape is rounded, rather than a angular cross-section like a quadrilateral. For example, a rounded cross-section that extends from the position on the worktable S opposite the front of the first nozzle 10a, i.e., along the width w of the scan line SL, at the central position, can be assumed to be the cross-section of the coating volume V according to an embodiment of the invention. Furthermore, the volume of the coating volume V assumed in this way, extending along the length L of the scan line SL per unit time, can be assumed to be the coating volume V of the first material M1 per unit time. For example, according to an embodiment of the invention, the coating volume V can be assumed to be a volume having a box shape formed at the central position along the width w of the scan line SL and semi-circular cross-sections formed at both sides of the box shape, and the cross-sectional shape formed by the combination of the box shape and the semi-circular cross-sections extending along the scan length of the first nozzle 10a.

[0219] Based on the above premise, the coating volume V of the first material M1 (coating volume V per unit time) can be calculated as follows.

[0220]

[0221] Here, L can refer to the distance of the scan line L per unit time.

[0222] According to one embodiment of the present invention, the coating volume V of the first material M1 forming the internal region of the model or the model itself surrounded by the outline of the model can be calculated based on the width w of the scan line SL forming the transfer path of the first nozzle 10a from which the first material M1 is ejected and the length L of the scan line SL per unit time corresponding to the transfer speed of the first nozzle 10a. Furthermore, the coating volume V of the first material M1 ejected from the first nozzle 10a can be calculated from the transfer path and transfer speed of the first nozzle 10a, which can be set based on the transfer plan of the first nozzle 10a.

[0223] According to one embodiment of the present invention, before the first and second nozzles 10a and 20a for forming the object are activated, a transfer plan for the first and second nozzles 10a and 20a can be established. This plan includes a pre-set of the transfer path, transfer speed, and coating volume V of the first material M1 and the second material M2 set based on the transfer path and transfer speed. In order to ensure that the first material M1 and the second material M2 can be ejected through the first nozzle 10a and the second nozzle 20a without being excessive or insufficient in the pre-set coating volume V of the first and second materials M1 and M2, for example, according to one embodiment of the present invention, the inner surface of the heating funnel 10 filled with liquid first material M1 can be formed. The internal pressure PI, more precisely, the pressure difference PIO between the inside and outside of the heating funnel 10, is such that the amount of the first material M1 ejected through the first nozzle 10a can accurately fill the pre-set coating volume V of the first material M1. In order to form such a pressure difference PIO between the inside and outside of the heating funnel 10, the inflow and outflow of gas GAS injected into or discharged from the heating funnel 10 are controlled. More specifically, the internal pressure PI of the heating funnel 10 is controlled to be bidirectional, either positive or negative, by the bidirectional pressure control unit 100 connected to the heating funnel 10. This can accelerate or decelerate the flow rate of the first material M1 flowing from the inside of the heating funnel 10 toward the outside of the worktable S.

[0224] According to one embodiment of the present invention, in the transfer plan of the first and second nozzles 10a and 20a set before the activity of the first and second nozzles 10a and 20a, the transfer speed of the first nozzle 10a and the second nozzle 20a can be set differently according to the shape of the outline of the object or the shape of the scan line SL that scans the internal area of ​​the object. For example, the first nozzle 10a and the second nozzle 20a can be transferred at a relatively delayed transfer speed on the scan line SL that forms the outline of the object including angular edges or the surface of the object. Conversely, the first nozzle 10a and the second nozzle 20a can be transferred at a relatively delayed transfer speed on the scan line SL that forms the outline of the object or the interior of the object that extends in a stripe shape in one direction. The first nozzle 10a and the second nozzle 20a are rapidly moved at different speeds. Based on these different moving speeds and in conjunction with the coating volumes V of the first material M1 and the second material M2, which are set differently according to the different moving speeds, the ejection speeds of the first material M1 and the second material M2 ejected through the first nozzle 10a and the second nozzle 20a can be controlled. For example, in order to control the discharge speed of the first material M1 and the second material M2, for example, in order to control the discharge speed of the first material M1 (acceleration or deceleration of the flow of the first material M1), the internal pressure PI of the heated funnel 10 filled with liquid first material M1 can be controlled. For example, on the scan line SL where the conveying speed of the first nozzle 10a ejecting the first material M1 is relatively delayed, in order to delay the ejection speed of the first material M1, the internal pressure PI of the heating funnel 10 of the liquid first material M1 can be formed into a positive pressure with a relatively small scale value. Alternatively, considering the relatively poor resolution of the control energy in the input / output relationship between the control of the internal pressure PI of the heating funnel 10 as input and the output of the change in the flow rate of the first material M1 flowing from the inside of the heating funnel 10 toward the outside of the worktable S, in the case of... On the scan line SL of the relatively delayed transfer speed, the internal pressure PI of the heating funnel 10 can be controlled to alternate between positive and negative pressure. For example, by applying positive pressure to the internal pressure PI of the heating funnel 10 to accelerate the flow rate of the first material M1 and reach a set flow rate or discharge amount of the first material M1, the internal pressure PI of the heating funnel 10 can be reversed to negative pressure to decelerate the flow rate of the first material M1. The discharge or flow rate of the first material M1 can be controlled to converge to a flow rate between a certain upper and lower limit.According to the embodiment described above, in which the discharge or flow rate of the first material M1 is controlled by alternating reversals of positive and negative pressure, the timing of the reversal of the positive and negative pressure can be captured, for example, by monitoring various state parameters that enable control of the flow of the first material M1. According to one embodiment of the present invention, the timing of the pressure reversal can be determined by combining state parameters measured or monitored at multiple locations, such as the internal pressure PI of the heating funnel 10 filled with liquid first material M1, the flow rate of the first material M1 flowing from the inside of the heating funnel 10 toward the outside, the ejection amount or ejection rate of the first material M1 ejected from the inside of the heating funnel 10 toward the outside of the worktable S, and the accumulation rate of the first material M1 accumulated on the worktable S.

[0225] According to one embodiment of the present invention, the bidirectional pressure control unit 100 can

[0226] Based on the insufficient coating volume V of the first material M1 per unit time set according to the transfer path and transfer speed of the first nozzle 10a, the pressure difference PIO between the inside and outside of the heating funnel 10 is set to a positive pressure to accelerate the flow of the first material M1 from the heating funnel 10 toward the first nozzle 10a, or

[0227] Based on the interference of the coating volume V of the second material M2 per unit time set according to the transfer path and transfer speed of the first nozzle 10a, the pressure difference PIO between the inside and outside of the heating funnel 10 is set to a negative pressure to reduce or brake the flow of the first material M1 from the heating funnel 10 toward the first nozzle 10a, and,

[0228] More specifically, the bidirectional pressure control unit 100 can

[0229] Based on the width w of the scan line SL forming the transport path of the first nozzle 10a, the pressure difference PIO between the inside and outside of the heating funnel 10 is set to positive pressure to accelerate the flow of the first material M1 from the heating funnel 10 toward the first nozzle 10a, or...

[0230] Based on the width w of the scan line SL that forms the transfer path of the first nozzle 10a, the pressure difference PIO between the inside and outside of the heating funnel 10 is set to a negative pressure to slow down or brake the flow of the first material M1 from the heating funnel 10 toward the first nozzle 10a, according to the reduction of the width w of the scan line SL.

[0231] For example, the bidirectional pressure control unit 100 can

[0232] Based on the conveying speed of the first nozzle 10a or based on the length L of the scan line SL per unit time corresponding to the conveying speed, corresponding to a relatively high conveying speed or a relatively long scan line SL per unit time, the pressure difference PIO between the inside and outside of the heating funnel 10 is set to a positive pressure to accelerate the flow of the first material M1 from the heating funnel 10 toward the first nozzle 10a, or

[0233] Based on the conveying speed of the first nozzle 10a or the scanning distance per unit time equivalent to the conveying speed, corresponding to a relatively low conveying speed or a relatively short scanning line SL per unit time, the pressure difference PIO between the inside and outside of the heating funnel 10 can be set to a negative pressure to slow down or brake the flow of the first material M1 from the heating funnel 10 toward the first nozzle 10a.

[0234] According to one embodiment of the present invention, the ejection amount or ejection speed of the first material M1 can be controlled by measuring and controlling the internal pressure PI of the heating funnel 10 filled with the first material M1 in various state parameters as described above (first pressure gauge 115). For example, compared with measuring and controlling state parameters such as the ejection amount or ejection speed of the first material M1, which are relatively difficult to measure, the measurement can be easily performed by the first pressure gauge 115 connected to the heating funnel 10. Furthermore, by directly and quickly controlling the flow rate of the first material M1 according to the internal pressure PI of the heating funnel 10, the speed of control in the input / output relationship can be improved.

[0235] According to one embodiment of the present invention, regardless of whether the scan line SL with a relatively delayed transfer speed is set according to the transfer speed of the first nozzle 10a or the scan line SL with a relatively rapid transfer speed is set, or regardless of whether the scan line SL with a variable transfer speed of the first nozzle 10a or the scan line SL with a constant transfer speed is set, the bidirectional pressure control unit 100 connected to the heating funnel 10 can be controlled by alternating positive and negative pressure, rather than by applying a constant positive pressure as described above.

[0236] According to various embodiments of the present invention, the internal pressure PI of the heating funnel 10 is alternately reversed between positive and negative pressure by means of the error between the internal pressure PI of the heating funnel 10 set in relation to the pre-set conveying speed of the first nozzle 10a and the real-time measured internal pressure PI of the heating funnel 10, or the error between the ejection amount or ejection speed of the first material M1 set in relation to the pre-set conveying speed of the first nozzle 10a and the real-time measured ejection amount or ejection speed of the first material M1.

[0237] A multiphase 3D printing apparatus according to an embodiment of the present invention may include...

[0238] A sealing cap CV, which covers and seals the inlet at the upper end of the heating funnel 10 and is face-to-face with the heating funnel 10; and

[0239] A sealing gasket GA is used to seal the space between the heating funnel 10 and the sealing cap CV.

[0240] For example, the heating funnel 10 includes a sealing flange 10f formed along the outer peripheral edge of the upper inlet, and,

[0241] The sealing gasket GA can be located between the heating flange 10f of the heating funnel 10 and the sealing cover CV, and is joined by the sealing flange 10f of the heating funnel 10 and the plate-shaped sealing cover CV that are formed through and parallel to each other.

[0242] For example, the heating funnel 10 and the sealing cap CV can be formed of a metallic material with a surface coating.

[0243] For example, the sealing gasket GA may include matrix sheets stacked on top of each other and ceramic fibers between the matrix sheets.

[0244] Hereinafter, a more detailed description will be given of one aspect of a multiphase 3D printing apparatus according to an embodiment of the present invention.

[0245] According to one embodiment of the present invention, in the heating funnel 10, the interior of the heating funnel 10 can be formed as a sealed space so that the internal pressure PI of the heating funnel 10 can be controlled by a bidirectional pressure control unit 100 fluidly connected to the heating funnel 10. For example, according to one embodiment of the present invention, the heating funnel 10 can be formed as a sealed space that is sealed to the external environment, such that the flow of the first material M1 filling the interior of the heating funnel 10 or the internal pressure PI of the heating funnel 10 can be controlled by the supply of positive or negative pressure controlled by a bidirectional pressure control unit 100 connected to the interior space or by the ejection of the first material M1 from the first nozzle 10a connected to the bottleneck position of the heating funnel 10. The internal pressure PI of the heating funnel 10 forming such a sealed space can be formed by the inflow and outflow of the substance filling the interior space. For example, the internal pressure PI of the heating funnel 10 can be completely controlled by the ejection of the first material M1 as the substance filling the interior space and the injection or discharge of gas GAS controlled by the bidirectional pressure control unit 100, and the fluctuation of the internal pressure PI of the heating funnel 10 caused by the external environment can be blocked. For example, according to one embodiment of the present invention, the control of the internal pressure PI of the heating funnel 10, which is not sealed by the external environment, may not be fully controlled by the bidirectional pressure control unit 100 due to the leakage of pressure between the internal pressure PI and the external environment.

[0246] According to one embodiment of the present invention, the heating funnel 10 fluidly connected to the bidirectional pressure control unit 100 can be formed as a sealed space sealed by the external environment, and the pressure control of the sealed space sealed by the external environment can be completely realized by the control of the bidirectional pressure control unit 100 by providing positive or negative pressure to the sealed space.

[0247] According to one embodiment of the present invention, the internal space of the heating funnel 10 can be sealed by a sealing cap CV and a sealing gasket GA, wherein the sealing cap CV covers the heating funnel 10 and the inlet formed at the upper end of the heating funnel 10, and the sealing gasket GA is located between the inlet of the heating funnel 10 and the sealing cap CV. According to one embodiment of the present invention, the heating funnel 10 may include a sealing flange 10f formed on the outer peripheral edge of the upper inlet. Through a joining means, the sealing flange 10f of the heating funnel 10 and the sealing cap CV, which is formed in a flat plate shape, are joined face-to-face. For example, the edge position of the heating funnel 10 forming the sealing flange 10f and the flange position of the sealing cap CV may have parallel and flat shapes and face each other. Since the joining member is inserted to continuously penetrate the edge position of the heating funnel 10 forming the sealing flange 10f and the flange position of the sealing cap CV, which are arranged face-to-face, the heating funnel 10 and the sealing cap CV can be joined together. According to one embodiment of the present invention, the heating funnel 10 and the sealing cap CV may be formed of the same heat-resistant material. For example, according to one embodiment of the present invention, the heating funnel 10 and the sealing cap CV may be formed of a ceramic material or a heat-resistant metal material with excellent heat resistance properties. According to various embodiments of the present invention, the heating funnel 10 and the sealing cap can be formed of ceramic or metallic materials. Ceramic materials are suitable for the heating funnel 10 and sealing cap CV of the present invention due to their excellent heat resistance and electrical insulation properties. However, according to various embodiments of the present invention, considering machinability and pressure loss due to the frictional flow of the first material M1 filling the interior of the heating funnel 10, the heating funnel 10 and the sealing cap CV can be formed of metallic materials, which provide lower flow resistance and lower pressure loss compared to ceramic materials due to their excellent machinability and relatively low surface roughness. According to one embodiment of the present invention, compared to the sealing cap CV formed in a flat plate shape, the heating funnel 10 formed in a funnel shape can be formed by machining a metal raw material. A surface coating can be formed on the surface of the heating funnel 10, which has a relatively high roughness due to the cutting marks formed by the cutting tool formed by machining the metal raw material. This coating is used to reduce the surface roughness of the heating funnel 10 and prevent damage such as corrosion from the high-temperature operating environment of the heating funnel 10. According to various embodiments of the present invention, similar to the heating funnel 10, the sealing cap CV for sealing the upper inlet of the heating funnel 10 can also be formed of a metal material similar to the heating funnel 10, for example, similar to the heating funnel 10, it can be formed with a surface coating.

[0248] According to one embodiment of the present invention, for the heating funnel 10 and the sealing cap CV, the edge positions of the heating funnel 10 with sealing flanges 10f and the edge positions of the sealing cap CV are arranged side-by-side facing each other, and can be joined together by a connecting member passing through the edge positions of the heating funnel 10 with sealing flanges 10f and the edge positions of the sealing cap CV, which are side-by-side facing each other. Furthermore, a sealing gasket GV is located between the joined heating funnel 10 and the sealing cap GV, achieving a complete seal therebetween. For example, according to one embodiment of the present invention, the sealing gasket GA can be formed of a material with excellent high-temperature heat resistance and sealing properties. For example, the sealing gasket GA can be formed of a material with cushioning or sealing properties that can maintain shape safety under high temperature and high pressure conditions between the heating funnel 10 and the sealing cap CV and can adaptably deform according to the shape therebetween. For example, according to one embodiment of the present invention, the sealing gasket GA can be formed as a composite material of multiple matrix sheets stacked on top of each other and ceramic fibers between the matrix sheets. For example, according to one embodiment of the present invention, the sealing gasket GA can be formed as a flexible graphite and carbon gasket GA.

[0249] According to one embodiment of the present invention, the pressure difference between the inside and outside of the heating funnel 10 can be set to a negative pressure to slow down or brake the flow of the first material M1 ejected from the inside of the heating funnel 10 toward the worktable S. Hereinafter, an exemplary embodiment in which the pressure difference between the inside and outside of the heating funnel 10 is set to a negative pressure will be described.

[0250] (1) The end position FP of the scan line SL along the transfer path forming the first nozzle 10a (refer to) Figure 17 )

[0251] According to one embodiment of the present invention, along the scanning line SL that forms the conveying path of the first nozzle 10a from which the first material M1 is ejected, at the end position FP (refer to) of the scanning line SL. Figure 17 The flow of the first material M1 can be rapidly braked by setting the pressure difference between the inside and outside of the heating funnel 10 containing the first material M1 to a negative pressure, for example, before the end position FP of the scan line SL (refer to...). Figure 17 In order to quickly interrupt the inertia of the first material M1 that tends to continue flowing along the scan line SL towards the external worktable S, which is about to be ejected or discharged from the worktable S, according to an embodiment of the present invention, the pressure difference between the inside and outside of the heating funnel 10 containing the first material M1 can be formed into a negative pressure, for example, at the end position FP of the scan line SL (refer to...). Figure 17 ) or adjacent to the end position FP (refer to Figure 17 The position is determined by blocking the previous positive pressure (closing the second fluid valve 121) and opening the negative pressure (opening the third fluid valve 131) at the end position FP of the scan line SL (refer to). Figure 17 This blocks the inertia of the first material M1, which tends to discharge from the heating funnel 10 toward the external worktable S, and immediately slows down or brakes the flow of the first material M1. For example, it can prevent the first material M1 from being ejected to a position FP that deviates from the predetermined transport path of the first nozzle 10a or the end position FP of the scanning line SL of the first nozzle 10a (see reference). Figure 17 The shape of the object formed by the first material M1 deviates from the intended shape and becomes distorted due to the position of the object.

[0252] For example, according to one embodiment of the present invention, a shape of a specific purpose can be formed by using the divided cross-sectional data of the object to be shaped as input to each layer of the stacked object. For example, each layer forming the object may include the transport path of the first nozzle 10a that ejects the first material M1 of the object itself, or the starting position SP along the transport path forming the first nozzle 10a (refer to...). Figure 17 ) and ending position FP (refer to Figure 17 At this point, at the end position FP of scan line SL (refer to...) Figure 17 On the scan line SL, by rapidly interrupting the inertia of the continuous flow of the first material M1, it is possible to prevent deviation from the predetermined end position FP of the scan line SL (refer to...). Figure 17 Afterwards, the first material M1 continues to flow or spray from inside the heating funnel 10 toward the worktable S outside, and the third fluid valve 131 connected to the third fluid pipe 130 of the tubing bundle connected to the negative pressure source NS and the second fluid valve 121 connected to the second fluid pipe 120 of the tubing bundle connected to the positive pressure source PS are opened to quickly block the inertia of the flow of the first material M1, that is, the inertia of the flow of the first material M1 from inside the heating funnel 10 containing the first material M1 toward the worktable S outside, and to brake the flow of the first material M1 and set the pressure difference between the inside and outside of the heating funnel 10 to a negative pressure.

[0253] According to one embodiment of the present invention, the inertia of the continuous ejection of the first material M1 on the scan line SL or the flow of the first material M1 towards the external worktable S includes the inertia of continuing the previous action if no pressure change or flow resistance change occurs in the flow of the first material M1 from the inside of the heating funnel 10 towards the external worktable S on the scan line SL. For example, in order to change the pressure difference between the inside and outside of the heating funnel 10 to slow down the flow of the first material M1, it can be used as a comprehensive meaning including the control by the valve controller 150 that controls the first to third fluid valves 111, 121, 131 and the delay of the control from the start of such control by the valve controller 150 until the actual change of the pressure difference between the inside and outside of the heating funnel 10 in response to the control by the valve controller 150. For example, unlike the present invention, in a comparative example that can set the pressure difference between the inside and outside of the heating funnel 10 to be both positive and negative, without a bidirectional pressure control unit 100, at the end position FP of the first nozzle 10a (refer to the present invention), Figure 17 While gradually reducing the positive pressure level, the flow of the first material M1 from the first nozzle 10a is slowed down. However, in this comparative example, it may be difficult to quickly slow down or brake the flow of the first material M1 from inside the heating funnel 10 toward the worktable S outside. For example, since the inertia of the flow of the first material M1, which is to be maintained or continued, is weakened relative to the gradually decreasing positive pressure level due to the relative increase in flow resistance, it may take a period of time to substantially slow down or brake the flow of the first material M1.

[0254] According to one embodiment of the present invention, at the end position FP of the scan line SL that forms the shape of the object (refer to...) Figure 17 Before and after, in order to form a sharp working step, the tail of the scan line SL is not formed inside or outside the shape of the object. In order to end the scan line SL at position FP (refer to...) Figure 17 Immediately interrupt the inertia of the flow of the first material M1 and immediately brake the flow of the first material M1 at the end position FP of the scan line SL (refer to...). Figure 17 The pressure difference between the inside and outside of the heating funnel 10 can be set to negative pressure. For example, the opening and closing of the second and third fluid valves 121 and 131 can be realized to connect the tube bundle to the second and third fluid tubes 120 and 130 of the positive pressure source PS and the negative pressure source NS, respectively.

[0255] (2) The end position FP of the scan line SL along the transfer path forming the first nozzle 10a (refer to) Figure 17 ) and the starting position SP (refer to) Figure 17 The coating termination interval ST between )

[0256] According to one embodiment of the present invention, a model can be formed by stacking or accumulating layers of the model using cross-sectional data of a slice of the model to be modeled as input to form the number of turns of the model. Based on this method of forming a model by stacking multiple layers or accumulating multiple turns, at the end position FP (refer to...) of the transfer path from the preceding layer (or the preceding turn, hereinafter the same) or the scan line SL forming the transfer path... Figure 17 The starting position SP of the transfer path or the scan line SL forming the transfer path from the preceding layer (or preceding turn, hereinafter the same) to the following layer (or following turn, hereinafter the same) stacked on the preceding layer (or preceding turn, hereinafter the same). Figure 17 Between the heating funnel 10 containing the first material M1, the pressure difference between the inside and outside is set to a negative pressure to slow down or brake the flow of the first material M1 that forms the object itself. For example, according to an embodiment of the present invention, the layers of the object can be formed by the accumulation of the preceding and subsequent turns, and the object can be formed by the stacking of the preceding and subsequent layers.

[0257] According to one embodiment of the present invention, a coating stop interval ST can be formed between the preceding layer (or preceding turn) and the subsequent layer (or subsequent turn) that are stacked to form the desired shape of the object, thereby stopping the coating of the first material M1. This is done at the end position FP of the preceding layer (referencing...). Figure 17 ) and the starting position of the subsequent layer SP (refer to Figure 17 To prevent the unexpected discharge of the first material M1 from occurring between the nozzle 10a and the outside of the heating funnel 10 containing the first material M1, and to properly follow this coating termination interval ST, the pressure difference between the inside and outside of the funnel 10 can be set to negative. For example, as described above, at the end position FP of the transport path of the first nozzle 10a that ejects the first material M1 or the scan line SL that forms the transport path of the first nozzle 10a (refer to...) Figure 17 The negative pressure imparted, i.e., at the end position FP of the scan line SL in the preceding layer (refer to...) Figure 17 The negative pressure applied can persist until the beginning of the scan line SL in subsequent layers (see reference). Figure 17 This prevents unexpected leakage of the first material M1 in the coating stop interval ST set between the leading layer and the trailing layer. Thus, according to one embodiment of the invention, the flow of the first material M1 in the coating stop interval ST can be blocked based on the pressure between the inside and outside of the heating funnel 10, rather than through a separate valve structure for fluid connection of the first nozzle 10a to the bottleneck portion of the heating funnel 10 via a tube bundle. However, according to various embodiments of the invention, based on the end position FP of the scan line SL in the leading layer (refer to...), Figure 17 The negative pressure setting is applied even at the beginning position SP of the subsequent scan line SL (refer to...). Figure 17 Before opening the second fluid valve 121 connecting the second fluid pipe 120 of the tube bundle to the positive pressure source PS, negative pressure is not applied, or the flow of the first material M1 can continue to stop due to its inertia. For example, according to various embodiments of the invention, since the first nozzle 10a for ejecting the first material M1 starts from the end position FP of the pilot layer (refer to...), the flow of the first material M1 continues to stop due to its inertia. Figure 17 Move to the beginning position SP of the next layer (refer to) Figure 17 ), at the beginning of the following layer SP (refer to Figure 17 It can perform a switch operation, which opens the second fluid valve 121 for connecting the tubing to the second fluid pipe 120 of the positive pressure source PS and closes the third fluid valve 131 for connecting the tubing to the third fluid pipe 130 of the negative pressure source NS.

[0258] (3) The active ranges T1 and T2 of the second nozzle 20a used to form the outline of the object (refer to) Figure 19 )

[0259] According to one embodiment of the present invention, after the shape outline is formed by operating the second nozzle 20a for forming the shape outline, the first material M1 can be filled into the internal molding area surrounded by the shape outline formed by the second material M2 discharged from the second nozzle 20a. That is, while the first nozzle 10a is activated, the molding area surrounded by the second material M2 under the height restriction of the second material M2 surrounding the molding area (refer to...) Figure 14 As described above, according to one embodiment of the present invention, a second nozzle 20a for ejecting the second material M2 to form the outline of a model and a first nozzle 10a for ejecting the first material M1 to form the model itself can be embedded in an insert block 40 that simultaneously restrains the first and second nozzles 10a and 20a, and can be arranged in adjacent fixed positions due to the constraint of such insert block 40. Furthermore, the first and second nozzles 10a and 20a can be moved alternately to alternately form the outline of each layer of the model and the single-layer structure of the model. The drive of the multiphase 3D printing apparatus according to one embodiment of the present disclosure may include the activity range T1 of the first nozzle 10a (see reference). Figure 19 ), wherein the first and second nozzles 10a and 20a, which are connected together, move along the transfer path of the first nozzle 10a or the scanning line SL of the first nozzle 10a, or the active range T2 of the second nozzle (refer to Figure 19 The embedded block 40, which connects the first and second nozzles 10a and 20a, moves along the transfer path of the second nozzle 20a or the scanning line SL of the second nozzle 20a. The active ranges T1 and T2 of these first and second nozzles 10a and 20a (refer to...) Figure 19It can be divided into mutually exclusive time slots and used.

[0260] According to one embodiment of the present invention, in the active range T2 of the second nozzle 20a (refer to...) Figure 19 During the activity period T2 of the second nozzle 20a, the activity of the first nozzle 10a can be stopped, and the pressure difference between the inside and outside of the heating funnel 10 containing the first material M1 can be set to a negative pressure to block unexpected leakage of the first material M1 from the first nozzle 10a during the activity period T2 of the second nozzle 20a. However, according to one embodiment of the present invention, the activity period T1 of the first nozzle 10a (refer to...) can be... Figure 19 The end position FP (refer to) Figure 17 The end position FP of the scan line SL of the first nozzle 10a forming the transfer path of the first nozzle 10a (refer to) Figure 17 The flow of the first material M1 is braked by the negative pressure of the pressure difference between the inside and outside of the heating funnel 10. Due to the inertia of the first material M1, which is to maintain the state of braked flow, the flow is slowed within the active range T1 of the first nozzle 10 (refer to...). Figure 19 The end position FP( Figure 17 The end position FP of the transfer path or scan line SL after (or the first nozzle 10a) (refer to) Figure 17 If no other negative pressure settings are implemented thereafter, the flow of the first material M1 from the heating funnel 10 containing the first material M1 toward the external worktable S can remain stopped.

[0261] (4) Control the first flow along the conveying path of the first nozzle 10a.

[0262] According to one embodiment of the present invention, in order to control the flow of the first material M1 along the conveying path of the first nozzle 10a or to increase the reaction rate by controlling the flow of the first material M1, the control of the flow of the first material M1 along the conveying path of the first nozzle 10a can be achieved by i) controlling the opening / closing of the second fluid valve 121 connected to the second fluid pipe 120 of the tube bundle connected to the positive pressure source PS and the opening / closing of the third fluid valve 131 connected to the third fluid pipe 130 of the tube bundle connected to the negative pressure source NS (see reference). Figure 16B and Figure 16CBy controlling the opening / closing of the second and third fluid valves 121 and 131, the valve control signals output from the valve controller 150 can be simplified to opening and closing control signals output from each of the second and third fluid valves 121 and 131, respectively. For example, it is not necessary to have multiple control signal levels set for controlling the opening of the second and third fluid valves 121 and 131, thereby simplifying the structure of the second and third fluid valves 121 and 131 and the structure of the valve controller 150 used to control these second and third fluid valves 121 and 131. In order to set the pressure difference between the inside and outside of the heating funnel 10 to multiple pressures by controlling the opening / closing of each of the second and third fluid valves 121 and 131, the opening / closing of each of the second and third fluid valves 121 and 131 can be alternately controlled while tracking the target pressure (see reference). Figure 16B and Figure 16C ).

[0263] According to one embodiment of the present invention, the control of the first flow along the conveying path of the first nozzle 10a can be achieved by ii) controlling the opening / closing and opening degree of the second fluid valve 121 connected to the second fluid pipe 120 of the tube bundle connected to the positive pressure source PS and controlling the opening / closing of the third fluid valve 131 connected to the third fluid pipe 130 of the tube bundle connected to the negative pressure source NS (see ii) Figure 18B and Figure 18CThis is achieved by controlling the flow of the first material M1 by controlling the second fluid valve 121, which can simultaneously control the opening and closing of the second fluid pipe 120 connected to the positive pressure source PS, and the third fluid valve 131, which can control the opening and closing of the third fluid pipe 130 connected to the negative pressure source NS. For example, along the transport path of the first nozzle 10a from which the first material M1 is ejected, or along the scan line SL forming the transport path, if it is necessary to slow down the flow of the first material M1, for example, by reducing the width w of the scan line SL based on the transport speed of the first nozzle 10a or the planned transport path, the valve controller 150 reduces the opening of the second fluid valve 121 connected to the second fluid pipe 120 of the tube bundle connected to the positive pressure source PS, while simultaneously opening and closing the third fluid valve 131 connected to the third fluid pipe 130 of the tube bundle connected to the negative pressure source NS with a short pulse waveform. For example, the control signal output from the valve controller 150 to the second fluid valve 121 can have a certain rising time or a certain falling time for reducing the opening of the second fluid valve 121. The control signal output from the valve controller 150 to the third fluid valve 131 can be output as a waveform with a sloping ramp (time) and, since the opening and closing of the third fluid valve 131 is achieved at short time intervals, the control signal can be output as a pulse waveform with no rise time and fall time or with short rise and fall times. Figure 18B and Figure 18C For example, according to one embodiment of the present invention, the valve controller 150 may output a control signal with a ramp waveform having a first rise time or a first fall time to reduce the opening of the second fluid valve 121, and may output a control signal with a pulse waveform having a second rise time or a second fall time shorter than the first rise time or the first fall time to sequentially control the opening and closing of the third fluid valve 131 (see reference). Figure 18B and Figure 18C ).

[0264] For example, according to one embodiment of the present invention, the second fluid valve 121 connected to the positive pressure source PS can form a control signal with a continuously varying form for controlling its opening, such as a waveform in the form of a ramp with a certain rise time. Therefore, the opening of the second fluid valve 121 includes the certain rise time and an additional time delay beyond the rise time. As a result, in controlling the opening of the second fluid valve 121, a certain degree of time delay is unavoidable for the transition from the first opening to the second opening (continuous variation from the first opening to the second opening). For example, the conveying speed varies discontinuously along the conveying path of the first nozzle 10a from which the first material M1 is ejected (e.g., the conveying speed varies between curved and straight sections). Alternatively, the width w of the scan line SL can vary discontinuously along the transport path of the first nozzle 10a discharging the first material M1 (e.g., according to the shape of the object or the transport path plan). Thus, in a driving environment that prefers discontinuous changes in the coating volume of the first material M1, while controlling the opening of the second fluid valve 121 connected to the positive pressure source PS side, i.e., while starting to control the opening of the second fluid valve 121, in order to induce discontinuous changes in the flow of the first material M1 following the discontinuous changes in the coating volume of the first material M1 from the instantaneous opening-closing control of the third fluid valve 131 connected to the negative pressure source NS side, the control of the second fluid valve 121 on the positive pressure source PS side and the third fluid valve on the negative pressure source NS side can be realized simultaneously.

[0265] As described above, according to one embodiment of the present invention, in different ways, i) the control method of controlling the flow of the first material M1 by controlling the opening / closing of the second fluid valve 121 on the positive pressure source PS side and controlling the opening / closing of the third fluid valve 131 on the negative pressure source NS side (see reference) Figure 16B and Figure 16C ) and ii) are control methods that control the flow of the first material M1 by controlling the opening / closing and opening degree of the second fluid valve 121 on the positive pressure source PS side and controlling the opening / closing of the third fluid valve 131 on the negative pressure source NS side. Figure 18B and Figure 18C The flow of the first material M1 can be controlled simultaneously by opening / closing the third fluid valve on the negative pressure source NS side and opening / closing the second fluid valve 121 on the positive pressure source PS side, or by controlling the opening / closing and degree of the second fluid valve 121 on the positive pressure source PS side. Furthermore, under a driving environment where the coating volume (coating volume per unit time) of the first material M1 is discontinuously varied, the flow of the first material M1 can be decelerated or braked simultaneously, and the transient response characteristics can be improved while following the variation of the coating volume of the first material M1 that is decreasing in accordance with the target.

[0266] As described above, according to one embodiment of the present invention, the second fluid valve 121 on the positive pressure source PS side can be controlled in an open / closed manner, or its opening degree can be controlled simultaneously with the open / closed manner. Unlike this different control method of the second fluid valve 121 on the positive pressure source PS side, the third fluid valve 131 on the negative pressure source NS side is controlled in an open / closed manner while inducing deceleration and braking of the fluid flow to the first material M1. In particular, it is used to induce deceleration and braking of discontinuous fluid flow to the first material M1, and can avoid the computational resources or computational burden of realizing opening degree control in addition to the control of the open / closed control of the third fluid valve 131 on the negative pressure source NS side.

[0267] (Transfer of the first and second nozzles 10a and 20a and the worktable S)

[0268] According to this specification, the transfer of the first and second nozzles 10a and 20a can include absolute transfer of the first and second nozzles 10a and 20a, and can also include relative transfer of the worktable S to the first and second nozzles 10a and 20a. For example, according to one embodiment of the present invention, by moving the worktable S accumulated by the first and second materials M1 and M2 ejected from the first and second nozzles 10a and 20a, substantially, the trajectory or trace of the first and second materials M1 and M2 following the planned transfer path on the worktable S is formed, which is the same as the transfer of the first and second nozzles 10a and 20a. Furthermore, the trajectory or trace of the first and second materials M1 and M2 accumulated on the worktable S by the relative transfer between the first and second nozzles 10a and 20a and the worktable S due to the transfer of the first and second nozzles 10a and 20a or the transfer of the worktable S can form the outline of the object and the object surrounded by the outline. For example, according to one embodiment of the present invention, the relative transfer of the first and second nozzles 10a and 20a on the worktable S can be achieved by the worktable S with a relatively shorter power transmission distance from the actuator A. According to this specification, the positional movement of the worktable S relative to the fixed position of the first and second nozzles 10a and 20a can be expressed as the transfer of the first and second nozzles 10a and 20a.

[0269] A multiphase 3D printing apparatus according to an embodiment of the present invention may include

[0270] A first nozzle 10a is used to spray liquid first material M1, which forms the shape, onto the worktable S and is filled with liquid first material M1. A bidirectional pressure control unit 100 is connected to the heating funnel 10 and is used to set the pressure difference PIO between the inside and outside of the heating funnel 10 to a positive or negative pressure.

[0271] It further includes a second nozzle 20a for discharging a paste-like or slurry-like second material M2 that forms the outline of the shaped object, and,

[0272] The width w of the scan line SL that forms the transfer path of the first nozzle 10a can be set to scan the overall styling area, wherein a styling object is formed, which is equivalent to a styling object outline surrounded by a filling space formed by the second material M2.

[0273] For example, a multiphase 3D printing apparatus according to an embodiment of the present invention may further include an extrusion device 80, which is connected to the second nozzle 20a and extrudes a second material M2 into the second nozzle 20a to spray out a paste or slurry-like second material M2 composed of ceramic particles and a matrix in which ceramic particles are dispersed.

[0274] For example, a multiphase 3D printing apparatus according to an embodiment of the present invention.

[0275] The chamber 50 can be further heated, which, while accommodating the worktable S, provides a slow cooling space 50' for the first and second materials M1 and M2 accumulated on the worktable S from the first and second nozzles 10a and 20a, and...

[0276] The pressure difference PIO between the inside and outside of the heating funnel 10 is based on the atmospheric pressure of the slow cooling space 50' of the heating funnel 50, which is equivalent to the internal pressure PI of the heating funnel 10 containing the liquid first material M1.

[0277] Hereinafter, a more detailed description will be given of one aspect of a multiphase 3D printing apparatus according to an embodiment of the present invention.

[0278] A multiphase 3D printing apparatus according to an embodiment of the present invention may include a controller 151, which includes

[0279] The workbench S provides a supporting foundation for the object being modeled.

[0280] First and second nozzles 10a and 20a are arranged on the worktable S to respectively discharge a paste-like or slurry phase of second material M2 that forms the outline of the shaped object and a liquid phase of first material M1 that fills the filling space surrounded by the outline of the shaped object formed by the second material M2.

[0281] An extrusion device 80 is connected to the second nozzle 20a and extrudes the second material M2 into the second nozzle 20a to discharge a paste or slurry-like second material M2 composed of ceramic particles and a matrix in which ceramic particles are dispersed.

[0282] A heating funnel 10, connected to the first nozzle 10a, melts a metal block to allow the flow of a first material M1, which is a liquid metal formed by ejecting the molten metal block through the first nozzle 10a as input; and

[0283] The heating chamber 50, which houses the worktable S, provides a slow cooling space 50' for the first and second materials M1 and M2 accumulated on the worktable S from the first and second nozzles 10a and 20a.

[0284] For the first material M1, the first material M1 can be formed as a liquid metal or metal flow formed by a heating funnel 10 that heats the metal block that has been put in with a solid metal block as input to the melting point or higher temperature. The molten metal or metal flow inside the heating funnel 10 can be discharged to the worktable S through the first nozzle 10a forming the lower end of the heating funnel 10.

[0285] For the second material M2, the second material M2 can be formed as a paste or slurry composite material of solid peach particles mixed with a liquid (or gel-like) carrier and / or binder. For example, the ceramic particles can have a particle size on the μm scale. This second material M2 is formed as a paste or slurry with dispersed ceramic ribs, so its flowability may be worse than that of the first material M1, which is formed as a liquid metal or metal flow. In order to form a uniform mixture (or uniform concentration dispersion) between the ceramic ribs (solid) and ceramic particles in different phases and in the contained matrix (liquid or gel-like), the second material M2 can be forcibly transferred by extrusion through the second nozzle 20a or the connecting tube 70 connected to the second nozzle 20a.

[0286] For example, the extrusion device 80 for extruding the first material M1 may include a first hopper 81 for feeding ceramic particles that form the solid components of the first material M1 and a second hopper 82 for feeding a matrix containing the ceramic particles to form a paste phase or slurry phase. The ceramic particles and matrix fed into the first and second hoppers 81 and 82 are fed together into the transfer tube 83 of the extrusion device 80. They are mixed together by rotating screws 85 formed inside the transfer tube 83 and transferred in the supply direction toward the worktable S. For example, the material M1 can be ejected onto the worktable S through a connecting tube 70 that mediates the transfer between the outlet 80a of the extrusion device 80 and a first nozzle 10a formed on the worktable S or an ejection unit 20 including a first nozzle 10a at the lower end, and ejected through the first nozzle 10a at the lower end of the ejection unit 20 embedded in the embedding block 40 described later. For example, according to one embodiment of the present invention, the upstream end of the connecting tube 70 may be connected to the outlet 80a of the extrusion device 80, and the downstream end of the connecting tube 70 may be connected to the ejection unit 20, which includes a first nozzle 10a at the lower end.

[0287] The heating funnel 10 and the ejection unit 20 can be embedded together in an embedding block 40. The embedding block 40 defines the interval between the first nozzle 10a forming the lower end of the heating funnel 10 and the second nozzle 20a forming the lower end of the ejection unit 20 by embedding and fixing the heating funnel 10 and the ejection unit 20 together in place. According to one embodiment of the present invention, the embedding block 40 can insulate the internal space of the heating funnel 10 from the surrounding environment while surrounding the first heat source 15 wrapped around the outer peripheral surface of the heating funnel 10, so as to maintain the temperature of the internal space of the heating funnel 10 controlled by the first heat source 15 at or above the melting point of the metal block, and can maintain the temperature of the ejection unit 20, which is arranged in the middle opposite the heating funnel 10 across the first heat source 15, at a temperature higher than the ambient temperature or room temperature but lower than the melting point of the metal block. According to one embodiment of the present invention, the embedding block 40 can be formed of a heat-insulating material.

[0288] According to one embodiment of the present invention, the embedding block 40 can be embedded in most of the heating funnel 10 and the ejection unit 20, exposing the inlet forming the upper end of the heating funnel 10 and the fitting end 20b forming the upper end of the ejection unit 20, and can expose the upper parts of these heating funnels 10 and ejection units 20, so that each includes the upper end of the heating funnel 10 for inserting the metal block and the upper end of the ejection unit 20 for connecting the tube body 70, with a certain remaining portion. According to one embodiment of the present invention, in the upper part of the embedding block 40, in addition to the inlet forming the upper end of the heating funnel 10 and the fitting end 20b forming the upper end of the ejection unit 20, the electrical contact 15a of the first heat source 15 surrounding the outer peripheral surface of the heating funnel 10 can also be exposed. The electrical contact 15a of the first heat source 15 can protrude to the highest level to block electrical interference with other surrounding structures. For example, it can protrude along the height direction Z1 to a level higher than the inlet of the heating funnel 10 and the fitting unit 20b of the ejection unit 20.

[0289] The embedding block 40 may include an upper block 41 formed with a relatively large height to embed most of the heating funnel 10 and the ejection unit 20, and a lower block 42 formed with an area larger than the upper block 41. It may also form a slow-cooling space 50', which includes an upper portion locked by the lower block 42, a side surface locked by the partition wall 50a of the heating funnel 50, and a lower portion locked by the bottom wall 50b of the heating funnel 50. For example, according to one embodiment of the invention, the slow-cooling space 50' can be formed by assembling the embedding block 40 and the heating chamber 50, with a second heat source 55 formed on the partition wall 50a of the heating chamber forming the slow-cooling space 50'. The heating chamber 50 can accommodate the worktable S while providing a slow-cooling space 50' for the first and second materials M1 and M2 accumulated on the worktable S from the first and second nozzles 10a and 20a. For example, according to one embodiment of the present invention, the pressure difference between the inside and outside of the heating funnel 10 is based on the pressure of the slow cooling space 50' of the heating chamber 50 (e.g., atmospheric pressure 1 atm), which is equivalent to the internal pressure of the heating funnel 10 containing the first material M1.

[0290] An opening 50” is formed on the bottom wall 50b of the heating funnel 50 to allow a power connection between the worktable S and the actuators A (first to third actuators). A connecting rod 200, which enables the power connection between the worktable S and the actuators A that provide driving power to the worktable S, passes through the opening 50”, thereby enabling a power connection between the worktable S and the actuators A. According to one embodiment of the present invention, the embedded block 40, the heating chamber 50, and the actuators A can be positioned and aligned with each other by means of an assembly guide rod R.

[0291] According to this specification, setting the pressure difference between the inside and outside of the heating funnel 10 to a negative pressure may include applying and blocking the negative pressure between the inside and outside of the heating funnel 10 for a relatively short period of time, and providing a negative pressure in the form of a step or pulse for a relatively short period of time to block the inertia of the flow of the first material M1 from the heating funnel 10 toward the worktable S. For example, according to this specification, setting the pressure difference between the inside and outside of the heating funnel 10 to a negative pressure may not necessarily mean that the negative pressure will not be released but will be maintained or will be maintained for a considerable period of time.

[0292] According to one embodiment of the present invention, before operating the first nozzle 10a, that is, before discharging the first material M1 from the first nozzle 10a, a path plan for the first nozzle 10a can be generated. For example, as a path plan for the first nozzle 10a, all configurations related to the discharge of the first material M1, such as injection transfer speed and discharge speed, can be set in the transfer path of the first nozzle 10a and at each position on the transfer path. However, according to various embodiments of the present invention, the discharge of the first material M1 from the first nozzle 10a may not necessarily be accompanied by the transfer of the first nozzle 10a, that is, the relative transfer between the first nozzle 10a and the worktable S. When the first nozzle 10a is in a state of stagnation due to the flow of the first material M1, that is, the relative position between the first nozzle 10a and the worktable S is fixed, the first material M1 ejected from the first nozzle 10a can fill the filling space inside the shape contour formed by the second material M2 based on the relatively high flowability. According to this embodiment, the pressure difference between the inside and outside of the heating funnel 10 can also be set to a negative pressure to block the inertia of the flow of the first material M1 from the heating funnel 10 toward the worktable S and stop the ejection of the first material M1.

[0293] According to one embodiment of the present invention, prior to the ejection of the first material M1, the conveying path and conveying speed of the first nozzle 10a can be planned based on the path of the first nozzle 10a ejecting the first material M1. In this case, the conveying path of the first nozzle 10a can be set to fill the space inside the contour of the object formed by the second material M2. For example, according to one embodiment of the present invention, the conveying path of the first nozzle 10a can be set such that the scan lines SL forming the conveying path do not overlap with each other, or the conveying path of the first nozzle 10a can be set such that the scan lines SL forming the conveying path partially overlap with each other. According to various embodiments of the present invention, the conveying path of the first nozzle 10a can be formed by scan lines SL that fill the contour of the object formed by the second material M2 while overlapping with each other, or it can be formed by scan lines SL that do not overlap with each other.

[0294] According to one embodiment of the present invention, the first and second nozzles 10a and 10b, respectively used for ejecting the first and second materials M1 and M2, can be integrated and transferred together by a joint structure that structurally unites these first and second nozzles 10a and 10b (e.g., embedded inside the embedding block 40 and structurally connected to each other). For example, when the first and second nozzles 10a and 10b are transferred along the transfer path of the first nozzle 10a, the first material M1 can be ejected from the first nozzle 10a, or when the first and second nozzles 10a and 10b are transferred along the transfer path of the second nozzle 10b, the second material M2 can be ejected from the second nozzle 10b. However, according to various embodiments of the present invention, the first and second nozzles 10a and 10b are conveyed at a certain interval and simultaneously eject the first and second materials M1 and M2, respectively. The shape is formed by accumulating the first material M1 in its internal position along the shape outline formed by the second material M2. For example, the shape outline and the shape itself can also be formed simultaneously by the integrated conveying of the first and second nozzles 10a and 10b. For example, the first and second nozzles 10a and 10b for ejecting the first and second materials M1 and M2 perform the discharge of the first material M1 following the conveying path of the first nozzle 10a and the ejection of the second material M2 following the conveying path of the second nozzle 10b at different time slots in the time sequence. The pressure difference between the inside and outside of the heating funnel 10 containing the first material M1 can be set to a negative pressure to block the leakage of the first material M1 when the second material M2 is ejected. The negative pressure setting for blocking the leakage of the first material M1 when the second material M2 is ejected can be implemented according to various needs or in various driving environments.

[0295] According to one embodiment of the present invention, for the purpose of controlling the flow of the first material M1 from the heating funnel 10 toward the worktable S, the control of opening / closing of the second fluid valve 121 connected to the positive pressure source PS and the control of opening / closing of the third fluid valve 131 connected to the negative pressure source NS can be alternately controlled to be inconsistent with each other. For example, taking into account the flow inertia inside the second fluid pipe 120 connected to the second fluid valve 121 and the third fluid pipe 130 connected to the third fluid valve 131, and the time delay between the input as the input of opening / closing the second and third fluid valves 121 and 131 and the output as the pressure difference between the inside and outside of the heating funnel 10, the opening and closing of these second and third fluid valves 121 and 131 can be controlled to overlap with each other in a portion along the time axis. For example, since the control of either one begins in a prior time step taking into account the flow inertia or time delay, the opening / closing of the second and third fluid valves 121 and 131 can be controlled to overlap with each other in a portion along the time axis. According to various embodiments of the present invention, the opening / closing of the second and third fluid valves 121 and 131 can be implemented in an exclusive manner that does not overlap with each other along the time axis.

[0296] According to one embodiment of the present invention, the bidirectional pressure control unit 100 (more specifically, the valve controller 150) can control the opening / closing and opening degree of the second fluid valve 121 connected to the positive pressure source PS, and can control the opening / closing and opening degree of the third fluid valve 131 connected to the negative pressure source NS. That is, according to one embodiment of the present invention, the valve controller 150 can control the opening / closing and opening degree of the third fluid valve 131 connected to the negative pressure source NS. For example, in order to set the negative pressure in advance along the time axis, depending on the length of the opening (ON) interval of the third fluid valve 131 connected to the negative pressure source NS, for example, if the in advance opening (ON) interval of the third fluid valve 131 is set to be relatively long, the opening degree of the third fluid valve 131 at the current time step can be controlled to be open with a relatively small width; if the in advance opening (ON) interval of the third fluid valve 131 is set to be relatively short, the opening degree of the third fluid valve 131 at the current time step can be controlled to be open with a relatively large width. For example, according to one embodiment of the present invention, if the opening (ON) range of the prior third fluid valve 131 is set to be relatively long and the internal pressure of the heating funnel 10 is in a relatively strong negative pressure state, then considering the driving load of the negative pressure source NS caused by the suction from the heating funnel 10 in a strong negative pressure state, the opening degree of the third fluid valve 131 can be controlled to be open with a small width. If the opening (ON) range of the prior third fluid valve 131 is set to be relatively short and the internal pressure of the heating funnel 10 is in a relatively weak negative pressure state, then it is not necessary to consider the driving load of the negative pressure source NS caused by the suction from the heating funnel 10 in a weak negative pressure state, and the opening degree of the third fluid valve 131 can be controlled to be open with a large width.

[0297] Reference Figure 15 The coating volume per unit time set based on the transfer path and transfer speed of the first nozzle 10a can be calculated based on the cross-sectional area of ​​the scan line SL, which includes the width w dimension and height h dimension of the scan line SL forming the transfer path of the first nozzle 10a, and the length L of the scan line SL per unit time corresponding to the transfer path.

[0298] Although the invention has been described with reference to the embodiments shown in the accompanying drawings, these are merely exemplary, and those skilled in the art to which this invention pertains should understand that various modifications and other equivalent embodiments can be implemented based thereon.

[0299] Industrial applicability

[0300] This invention can be applied to 3D printing devices and related technical fields.

Claims

1. A multiphase three-dimensional (3D) printing apparatus, characterized in that, include: The first nozzle is used to spray the liquid first material that forms the shape onto the worktable; A heating funnel, connected to the first nozzle and filled with a liquid first material; and A bidirectional pressure control unit is connected to the heating funnel and is used to alternately reverse the pressure difference between the inside and outside of the heating funnel between positive and negative pressure, and is used to i) accelerate the flow of the first material from the heating funnel toward the first nozzle according to the positive pressure, and ii) decelerate the flow of the first material from the heating funnel toward the first nozzle or apply braking to the flow of the first material according to the negative pressure.

2. The multiphase 3D printing apparatus according to claim 1, characterized in that, The bidirectional pressure control unit brakes the flow of the first material from the heating funnel toward the first nozzle by setting the pressure difference between the inside and outside of the heating funnel to a negative pressure.

3. The multiphase 3D printing apparatus according to claim 1, characterized in that, The bidirectional pressure control unit provides a suction force toward the heating funnel by setting the pressure difference between the inside and outside of the heating funnel to a negative pressure, or by setting it to include negative pressure pulses that apply and block negative pressure, to prevent the flow of the first material from being ejected from the heating funnel toward the first nozzle.

4. The multiphase 3D printing apparatus according to claim 1, characterized in that, The bidirectional pressure control unit sets the pressure difference between the inside and outside of the heating funnel to a negative pressure at the end position of the transfer path of the first nozzle or at the end position of the scan line forming the transfer path of the first nozzle, or sets it to a negative pressure pulse that includes the application and blocking of negative pressure.

5. The multiphase 3D printing apparatus according to claim 1, characterized in that, The bidirectional pressure control unit sets the pressure difference between the inside and outside of the heating funnel to a negative pressure, or sets it to a negative pressure pulse that includes the application and blocking of negative pressure, along the transfer path of the first nozzle or the scan line forming the transfer path of the first nozzle, in the interval between the end position and the start position of the scan line.

6. The multiphase 3D printing apparatus according to claim 1, characterized in that, When forming a shape through the accumulation of preceding and subsequent turns, and the layering of preceding and subsequent layers, Along the transport path of the first nozzle, the end position and start position of the scan line forming the transport path of the first nozzle are between the leading turn and the trailing turn and between the leading layer and the trailing layer.

7. The multiphase 3D printing apparatus according to claim 6, characterized in that, Along the conveying path of the first nozzle, Between the end position of the scan line in the preceding turn and the beginning position of the scan line in the subsequent turn; and A coating stop interval is formed between the end position of the scan line in the preceding layer and the start position of the scan line in the subsequent layer, and... The bidirectional pressure control unit sets the pressure difference between the inside and outside of the heating funnel to a negative pressure during the coating stop interval, or sets it to a negative pressure pulse that includes the application and interruption of negative pressure.

8. The multiphase 3D printing apparatus according to claim 1, characterized in that, It further includes a second nozzle for spraying a second material to form the outline of the shape, and, When the second material is ejected, in order to block the ejection of the first material, the bidirectional pressure control unit sets the pressure difference between the inside and outside of the heating funnel to a negative pressure, or sets it to a negative pressure pulse that includes the application and blocking of negative pressure.

9. The multiphase 3D printing apparatus according to claim 8, characterized in that, The active range of the first nozzle, wherein the first and second nozzles, which are connected to each other, are moved together along the conveying path of the first nozzle. The active range of the second nozzle, in which the first and second nozzles, which are connected to each other, are moved together along the conveying path of the second nozzle. The molding processes used to create shapes are divided into mutually exclusive time periods.

10. The multiphase 3D printing apparatus according to claim 1, characterized in that, The bidirectional pressure control unit includes: A first fluid valve is used to connect the tube bundle to the first fluid tube and the connection of the first fluid tube of the heating funnel; A second fluid valve is used to connect the tubing bundle to the second fluid pipe and the second fluid pipe of the positive pressure source; A third fluid valve is used for connecting the tubing bundle to a third fluid pipe and the connection of the third fluid pipe to a negative pressure source; and Valve controller, which is used to control the first to third fluid valves, wherein, The valve controller controls the opening / closing of the second fluid valve and the third fluid valve.

11. The multiphase 3D printing apparatus according to claim 10, characterized in that, The valve controller alternately controls the opening / closing of the second fluid valve and the opening / closing of the third fluid valve to be inconsistent with each other, and exclusively controls them to include partial overlap or non-overlap along the time axis.

12. The multiphase 3D printing apparatus according to claim 10, characterized in that, The valve controller controls the opening / closing and opening degree of the second fluid valve and the opening / closing and opening degree of the third fluid valve.

13. The multiphase 3D printing apparatus according to claim 12, characterized in that, The valve controller, in conjunction with the control of reducing the opening of the second fluid valve, simultaneously achieves sequential control of opening and closing of the third fluid valve.

14. The multiphase 3D printing apparatus according to claim 13, characterized in that, The valve controller outputs a control signal with a sloping ramp waveform having a first rise time or a first fall time to control the reduction of the opening of the second fluid valve. A control signal with a pulse waveform having a second rise time or a second fall time shorter than the first rise time or the first fall time is output to achieve sequential control of the opening and closing of the third fluid valve.

15. The multiphase 3D printing apparatus according to claim 1, characterized in that, The bidirectional pressure control unit sets the pressure difference between the inside and outside of the heating funnel to a positive pressure to accelerate the flow of the first material from the heating funnel toward the first nozzle, based on the insufficient coating volume of the first material per unit time set according to the transfer path and transfer speed of the first nozzle. The pressure difference between the inside and outside of the heating funnel is set to a negative pressure based on the interference of the coating volume of the second material per unit time, which is set according to the transfer path and transfer speed of the first nozzle, to reduce or brake the flow of the first material from the heating funnel toward the first nozzle.

16. The multiphase 3D printing apparatus according to claim 15, characterized in that, Based on the coating volume of the first material per unit time, set according to the transfer path and transfer speed of the first nozzle, the pressure difference between the inside and outside of the heating funnel is set to positive or negative pressure to accelerate or decelerate the flow of the first material from the heating funnel toward the first nozzle, or to brake the flow of the first material. The coating volume of the first material per unit time is calculated based on the product of the cross-sectional area of ​​the scan line based on the width of the scan line forming the transfer path or the width and height dimensions of the scan line and the scan line length per unit time corresponding to the transfer speed.

17. The multiphase 3D printing apparatus according to claim 1, characterized in that, The heating funnel includes a circumferential surface that is wider at the top and narrower at the bottom. Its inner diameter gradually decreases from the upper inlet where the metal block of the first material is fed in to the bottleneck portion of the first nozzle connected to the lower end from which the liquid first material is ejected. The flow of the first liquid material is affected by flow friction acting from the circumferential surface of the heating funnel and by a bottleneck portion that restricts the flow of the first material, resulting in pressure loss.

18. The multiphase 3D printing apparatus according to claim 17, characterized in that, When the heated funnel is filled with a limited capacity and ejected from inside the funnel onto the external worktable, the pressure loss caused by the flow of the first material from inside the heated funnel toward the outside is reduced.

19. The multiphase 3D printing apparatus according to claim 18, characterized in that, The bidirectional pressure control unit controls the pressure difference between the inside and outside of the heating funnel while maintaining a constant, steady-state flow rate of the first material ejected from the inside of the heating funnel onto the worktable outside, so that... i) The pressure difference between the inside and outside of the heating funnel decreases together to offset the reduced pressure loss due to the ejection of the first material, or ii) The reduction in the weight of the first material and the reduction in pressure loss due to the ejection of the first material acting in the opposite direction to the flow of the first material are offset from each other and the pressure difference between the inside and outside of the heating funnel remains the same.

20. The multiphase 3D printing apparatus according to claim 1, characterized in that, A sealing cap, which covers and seals the inlet at the upper end of the heating funnel and is engaged with the heating funnel; and A sealing gasket, used to seal the space between the heating funnel and the sealing cap.

21. The multiphase 3D printing apparatus according to claim 20, characterized in that, The heating funnel includes a sealing flange formed along the outer peripheral edge of the upper inlet, and, The sealing gasket is located between the sealing flange of the heating funnel and the sealing cap, and is joined to each other by a means of engagement through which the sealing flange of the heating funnel and the plate-shaped sealing cap are formed side by side.

22. The multiphase 3D printing apparatus according to claim 1, characterized in that, The bidirectional pressure control unit includes, A first fluid tube extends from the common confluence location toward the heating funnel; The second fluid pipe is connected from the common confluence location to the positive pressure source; as well as The third fluid pipe connects to the negative pressure source from the common confluence location.

23. The multiphase 3D printing apparatus according to claim 22, characterized in that, The bidirectional pressure control unit further includes, A first fluid valve is connected on the first fluid pipe between the common confluence location and the heating funnel; A first pressure gauge is connected on the first fluid tube between the heating funnel and the first fluid valve; A second fluid valve is connected on the second fluid pipe between the common confluence location and the positive pressure source; A second pressure gauge is connected on the second fluid tube between the positive pressure source and the second fluid valve; A third fluid valve, connected on the third fluid pipe between the common confluence location and the negative pressure source; and A third pressure gauge is connected on the third fluid tube between the negative pressure source and the third fluid valve.

24. The multiphase 3D printing apparatus according to claim 23, characterized in that, The bidirectional control unit further includes a valve controller connected to each of the first to third fluid valves and for applying control signals to each of the first to third fluid valves for controlling the opening and closing of the valve and the degree of valve opening.

25. The multiphase 3D printing apparatus according to claim 24, characterized in that, The valve controller controls the opening of the first and second fluid valves to set the pressure difference between the inside and outside of the heating funnel to a positive pressure, and, The first and third fluid valves are opened to set the pressure difference between the inside and outside of the heating funnel to a negative pressure.

26. The multiphase 3D printing apparatus according to claim 1, characterized in that, The second nozzle is used to spray a paste-like or slurry-like second material to form the outline of the object, and, The width of the scan line forming the transfer path of the first nozzle is set to scan the overall modeling area, wherein a model is formed that is equivalent to a filling space surrounded by the outline of the model formed by the second material.

27. The multiphase 3D printing apparatus according to claim 26, characterized in that, Further includes: An extrusion device connected to the second nozzle and extruding the second material into the second nozzle to spray out a paste or slurry-like second material consisting of ceramic particles and a matrix in which the ceramic particles are dispersed.

28. The multiphase 3D printing apparatus according to claim 26, characterized in that, Further includes: A heating chamber that houses the worktable and provides a slow-cooling space for the first and second materials accumulated on the worktable from the first and second nozzles, and... Based on the atmospheric pressure in the slow cooling space of the heating chamber, the pressure difference between the inside and outside of the heating funnel is equivalent to the internal pressure of the heating funnel containing the liquid first material.

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