A multi-phase 3D printing device that embodies sophisticated control over the flow of the material that forms the object.

Abstract

The present invention discloses a multiphase three-dimensional printing apparatus. According to the present invention, the apparatus includes a bidirectional pressure control unit that can control pressure in both directions, such as positive pressure for accelerating the flow of the first material that forms the molded object and negative pressure for decelerating or braking the flow of the first material, thereby enabling precise control of the flow of the first material. For example, it is possible to provide a control means that can control the flow of the first material in real time during the molding process so as to satisfy without excess or deficiency the coating volume per unit time, which is set from the width of the scan line forming the transport path of the first discharge unit for discharging the flow of the first material and the length of the scan line per unit time corresponding to the transport speed of the first discharge unit.

Description

Technical Field

[0001] The present invention relates to a multiphase three-dimensional printing apparatus.

Background Art

[0002] A three-dimensional printing apparatus is a device used to form a shaped object having a specific shape. For example, a shaped object can be manufactured by inputting sliced section data of the shaped object to be formed and stacking each layer of the shaped object in such a way that the layers are stacked. For example, in such a three-dimensional printing apparatus, the three-dimensional shape of the shaped object to be formed is generated as digital data through computer modeling work, differentiated into a two-dimensional plane, and then a three-dimensional shaped object can be manufactured by stacking and laminating the differentiated materials.

Summary of the Invention

Problems to be Solved by the Invention

[0003] One embodiment of the present invention includes a bidirectional pressure control unit capable of controlling pressure in both directions, including a positive pressure for accelerating the flow of a first material forming a shaped object and a negative pressure for decelerating or braking the flow of the first material, enabling precise control of the flow of the first material. A multiphase three-dimensional printing apparatus can be included that is capable of controlling in real time the flow of the first material in a shaping process so as to exactly fill the application volume per unit time set from the width of a scan line forming a transfer path of a first discharge unit for discharging the flow of the first material and the length of the scan line per unit time corresponding to the transfer speed of the first discharge unit.

Means for Solving the Problems

[0004] To solve the above problems and other problems, the multiphase three-dimensional printing apparatus of the present invention a first discharge nozzle for discharging a first liquid-phase material for forming a shaped object onto a stage; A heating funnel to which the first discharge nozzle is connected and which is filled with a first liquid phase material; and Connected to the heating funnel, and for alternatingly reversing the pressure difference between the inside and outside of the heating funnel between positive and negative pressure, the unit includes a bidirectional pressure control unit for i) accelerating the flow of the first material from the heating funnel toward the first discharge nozzle by positive pressure, and ii) decelerating or braking the flow of the first material from the heating funnel toward the first discharge nozzle by negative pressure. [Effects of the Invention]

[0005] According to the present invention, a multiphase 3D printing apparatus is provided that includes a bidirectional pressure control unit capable of controlling pressure in both directions, such as positive pressure for accelerating the flow of the first material that forms the molded object and negative pressure for decelerating or braking the flow of the first material, thereby enabling precise control of the flow of the first material. For example, it is possible to provide a multiphase 3D printing apparatus that includes a bidirectional pressure control unit capable of controlling the flow of the first material in real time during the molding process so as to satisfy without excess or deficiency the coating volume per unit time, which is set from the width of the scan line forming the transport path of the first discharge unit for discharging the flow of the first material and the length of the scan line per unit time corresponding to the transport speed of the first discharge unit. [Brief explanation of the drawing]

[0006] [Figure 1] This is an overall perspective view of a multiphase 3D printing apparatus according to one embodiment of the present invention. [Figure 2] Figure 1 is a plan view showing a partial configuration of the multiphase three-dimensional printing apparatus. [Figure 3] Figure 1 shows a multiphase three-dimensional printing apparatus, and Figure 2 shows a cross-sectional view taken along the line III-III'. [Figure 4]Figure 1 illustrates the formation of a molded object, which is created from the first and second ejection positions on the stage S where different first and second materials M1 and M2 are ejected, and the molding of a molded object that fills the filling space surrounded by the contour of the molded object, in a multiphase three-dimensional printing apparatus shown in Figure 1. [Figure 5] This is a diagram illustrating the extrusion apparatus 80 shown in Figure 1, and shows a schematic configuration of the extrusion apparatus 80 in Figure 1. [Figure 6] Figure 1 is an exploded perspective view illustrating a part of the multiphase three-dimensional printing apparatus shown, illustrating the sealing structure of the heating funnel 10 and the sealing cover CV, which are coupled to each other via a sealing gasket GA. [Figure 7] Figure 1 shows a part of a multiphase three-dimensional printing apparatus, and is a diagram illustrating the flow resistance that causes pressure loss in the flow of the liquid phase first material M1 from the heating funnel 10 toward the first discharge nozzle 10a. [Figure 8] Figure 1 shows a part of a multiphase three-dimensional printing apparatus, illustrating the pressure difference PIO inside and outside the heating funnel 10, which is set to positive pressure, in order to accelerate the flow of the liquid phase first material M1 from the heating funnel 10 toward the first discharge nozzle 10a. [Figure 9] Figure 1 is a part of a multiphase three-dimensional printing apparatus, and is a diagram illustrating the pressure difference PIO between the inside and outside of the heating funnel 10, which is set to a negative pressure, in order to slow down or brake the flow of the liquid phase first material M1 from the heating funnel 10 toward the first discharge nozzle 10a. [Figure 10A] The following are different profiles illustrating the temporal changes in the volumetric flow rate of the gas GAS injected to maintain a steady state of the flow of liquid-phase first material M1 discharged from the first discharge nozzle 10a, the volumetric flow rate of the gas GAS injected to maintain a steady state of the flow of liquid-phase first material M1 discharged from the first discharge nozzle 10a, along the time axis. [Figure 10B]The following are different profiles illustrating the temporal changes in the volumetric flow rate of the gas GAS injected to maintain a steady state of the flow of liquid-phase first material M1 discharged from the first discharge nozzle 10a, the volumetric flow rate of the gas GAS injected to maintain a steady state of the flow of liquid-phase first material M1 discharged from the first discharge nozzle 10a, along the time axis. [Figure 10C] The following are different profiles illustrating the temporal changes in the volumetric flow rate of the gas GAS injected to maintain a steady state of the flow of liquid-phase first material M1 discharged from the first discharge nozzle 10a, the volumetric flow rate of the gas GAS injected to maintain a steady state of the flow of liquid-phase first material M1 discharged from the first discharge nozzle 10a, along the time axis. [Figure 10D] The following are different profiles illustrating the temporal changes in the volumetric flow rate of the gas GAS injected to maintain a steady state of the flow of liquid-phase first material M1 discharged from the first discharge nozzle 10a, the volumetric flow rate of the gas GAS injected to maintain a steady state of the flow of liquid-phase first material M1 discharged from the first discharge nozzle 10a, along the time axis. [Figure 11] Figure 1 is a diagram illustrating one embodiment of the bidirectional pressure control unit 100 shown in Figure 1, and schematically shows the configuration of the bidirectional pressure control unit 100 that controls the injection and exhaust of gas GAS to the heating funnel 10 so as to set the pressure difference PIO between the inside and outside of the heating funnel 10 to positive and negative pressure in both directions. [Figure 12] This figure illustrates another embodiment of the bidirectional pressure control unit 100 shown in Figure 1, and schematically shows a bidirectional pressure control unit 100 that controls the injection and exhaust of gas GAS to the heating funnel 10 so as to set the pressure difference PIO between the inside and outside of the heating funnel 10 to positive and negative pressure in both directions. [Figure 13] This figure illustrates yet another embodiment of the bidirectional pressure control unit 100 shown in Figure 1, schematically showing a bidirectional pressure control unit 100 that controls the injection and exhaust of gas GAS to the heating funnel 10 so as to set the pressure difference PIO between the inside and outside of the heating funnel 10 to positive and negative pressure in both directions. [Figure 14] This figure illustrates the width w of the scanline SL, corresponding to the transport path followed by the first material M1, which is set to scan the entire region of the object surrounded by the contour of the object formed by the second material M2. [Figure 15] This figure illustrates the calculation of the cross-sectional area of ​​the scanline SL, including the width w dimension of the scanline SL, according to the transport path shown in Figure 14, and the coating volume V per unit time, corresponding to the length L of the scanline SL per unit time, which is set according to the transport speed. [Figure 16A] This diagram shows the ON / OFF control signals for the first fluid valve 111 output from the valve controller 150 over time. [Figure 16B] This diagram shows the ON / OFF control signals for the second fluid valve 121 output from the valve controller 150 over time. [Figure 16C] This diagram shows the ON / OFF control signals for the third fluid valve 131 output from the valve controller 150 over time. [Figure 17] This figure illustrates a coating interruption section ST between the end position FP of the scan line SL of the preceding turn and the start position SP of the scan line SL of the following turn, in a molding process in which a molded object is formed from the accumulation of preceding and succeeding turns along the transfer path of a first discharge nozzle from which a first material is discharged. [Figure 18A]It is a diagram showing a stepped profile regarding the pressure difference between the inside and outside of a heating funnel as a control target. [Figure 18B] It is a diagram showing a control signal for controlling the opening degree of a second fluid valve output so as to follow the pressure difference between the inside and outside of a stepped heating funnel as a control target. [Figure 18C] It is a diagram showing a profile of an on / off control signal of a third fluid valve as a control target. [Figure 19] It is a diagram for explaining drive intervals T1 and T2 of first and second discharge nozzles 10a and 20a divided into mutually exclusive time slots on a shaping process for forming a shaped object.

Embodiments for Carrying Out the Invention

[0007] In order to solve the above problems and other problems, the multiphase three-dimensional printing apparatus of the present invention includes a first discharge nozzle for discharging a first material in a liquid phase for forming a shaped object on a stage, a heating funnel which is connected to the first discharge nozzle and filled with the first material in a liquid phase, a bidirectional pressure control unit which is connected to the heating funnel and is for alternately reversing the pressure difference between the inside and outside of the heating funnel between a positive pressure and a negative pressure, and i) accelerating the flow of the first material from the heating funnel toward the first discharge nozzle by the positive pressure, and ii) decelerating or braking the flow of the first material from the heating funnel toward the first discharge nozzle by the negative pressure.

[0008] For example, the bidirectional pressure control unit sets the pressure difference between the inside and outside of the heating funnel to a negative pressure to brake the flow of the first material from the heating funnel toward the first discharge nozzle.

[0009] For example, the bidirectional pressure control unit sets the pressure difference between the inside and outside of the heating funnel to a negative pressure or a negative pressure pulse including the application and interruption of negative pressure, and provides a suction force toward the heating funnel so that the flow of the first material is not discharged from the heating funnel toward the first discharge nozzle.

[0010] For example, the bidirectional pressure control unit is At the end position of the transfer path of the first discharge nozzle or the end position of the scan line forming the transfer path of the first discharge nozzle, the pressure difference between the inside and outside of the heating funnel is set to a negative pressure or a negative pressure pulse including the application and interruption of negative pressure.

[0011] For example, the bidirectional pressure control unit is Along the transfer path of the first discharge nozzle or the scan line forming the transfer path of the first discharge nozzle, the pressure difference between the inside and outside of the heating funnel is set to a negative pressure or a negative pressure pulse including the application and interruption of negative pressure in the section between the end position of the scan line and the start position of the scan line.

[0012] For example, when forming an object by accumulating the preceding and succeeding turns, and by laminating the preceding and succeeding layers, Along the transfer path of the first discharge nozzle, the end and start positions of the scan line forming the transfer path of the first discharge nozzle are interposed between the preceding turn and the succeeding turn, and between the preceding layer and the succeeding layer.

[0013] For example, along the transfer path of the first discharge nozzle, Between the end position of the scanline in the preceding turn and the start position of the scanline in the following turn, A coating interruption section is formed between the end position of the scan line in the preceding layer and the start position of the scan line in the following layer. The bidirectional pressure control unit sets the pressure difference between the inside and outside of the heating funnel to a negative pressure or a negative pressure pulse that includes the application and interruption of negative pressure during the coating interruption section.

[0014] For example, the multiphase three-dimensional printing apparatus is The system further includes a second discharge nozzle for dispensing a second material to form the contour of the molded object, The bidirectional pressure control unit sets the pressure difference between the inside and outside of the heating funnel to a negative pressure or a negative pressure pulse that includes the application and interruption of negative pressure, so as to interrupt the discharge of the first material when the second material is discharged.

[0015] For example, a drive section of the first discharge nozzle in which the first and second discharge nozzles, which are bound together, are transported together along the transport path of the first discharge nozzle, A drive section of the second discharge nozzle in which the first and second discharge nozzles, which are bound together, are transported together along the transport path of the second discharge nozzle, The molding process for creating the object is divided into mutually exclusive time slots.

[0016] For example, the bidirectional pressure control unit is A first fluid tube connected to the heating funnel, and a first fluid valve for disconnecting and reconnecting the first fluid tube, A second fluid pipe connected to a positive pressure source, and a second fluid valve for disconnecting the connection of the second fluid pipe, A third fluid pipe connected to a negative pressure source, and a third fluid valve for disconnecting the connection of the third fluid pipe, Includes a valve controller for controlling the first to third fluid valves, The valve controller implements on / off control for the second fluid valve and on / off control for the third fluid valve.

[0017] For example, the valve controller is The on / off states of the second fluid valve and the third fluid valve are controlled alternately, either partially overlapping with each other along the time axis, or exclusively alternating without overlapping.

[0018] For example, the valve controller implements the on / off and opening degree control of the second fluid valve, and the on / off and opening degree control of the third fluid valve.

[0019] For example, the valve controller is This implements sequential on / off control of the third fluid valve, along with control to reduce the opening degree of the second fluid valve.

[0020] For example, the valve controller is To control the opening degree of the second fluid valve, a control signal with a sloped ramp waveform having a first rising time or a first falling time is output. For sequential on / off control of the third fluid valve, a control signal in the form of a pulse waveform is output, having a second rise period or second fall time that is shorter than the first rise period or first fall time.

[0021] For example, the bidirectional pressure control unit is Depending on the transfer path and transfer speed of the first discharge nozzle, the pressure difference between the inside and outside of the heating funnel is set to a positive pressure in response to the insufficient coating volume of the first material per unit time, thereby accelerating the flow of the first material from the heating funnel toward the first discharge nozzle, or, In accordance with the transfer path and transfer speed of the first discharge nozzle, the pressure difference between the inside and outside of the heating funnel is set to a negative pressure in response to an excess of the second material's coating volume per unit time, thereby reducing or braking the flow of the first material from the heating funnel toward the first discharge nozzle.

[0022] For example, the pressure difference between the inside and outside of the heating funnel is set to positive or negative pressure according to the coating volume per unit time of the first material, which is set according to the transfer path and transfer speed of the first discharge nozzle, thereby accelerating, decreasing, or braking the flow of the first material from the heating funnel toward the first discharge nozzle. The coating volume of the first material per unit time can be calculated by multiplying the width of the scan line forming the transport path, or the cross-sectional area of ​​the scan line including the width dimension and height dimension of the scan line, by the length of the scan line per unit time, which corresponds to the transport speed.

[0023] For example, the heating funnel includes a circumferential surface that is wider at the top and narrower at the bottom, with an inner diameter that gradually decreases from the inlet at the upper end into which the metal block of the first material is inserted, to the bottleneck portion connected to the first discharge nozzle at the lower end from which the liquid phase of the first material is discharged. With respect to the flow of the liquid phase of the first material, the fluid friction acting on the circumferential surface of the heating funnel and the bottleneck portion that limits the flow rate of the first material cause pressure loss in the flow of the first material.

[0024] For example, as the first material, which is filled to a limited capacity inside the heating funnel, is discharged from the inside of the heating funnel onto an external stage, the pressure loss caused in the flow of the first material from the inside of the heating funnel to the outside is reduced.

[0025] For example, the bidirectional pressure control unit is Under a steady-state condition in which the amount of the first material discharged from the inside of the heating funnel toward the external stage is kept constant, i) To offset the pressure loss that decreases with the discharge of the first material, the pressure difference between the inside and outside of the heating funnel decreases, or ii) The discharge of the first material causes the decrease in the weight of the first material and the decrease in pressure loss, which act in opposing directions on the flow of the first material, to cancel each other out, so that the pressure difference between the inside and outside of the heating funnel is maintained equal. The pressure difference between the inside and outside of the heating funnel is controlled.

[0026] For example, the multiphase three-dimensional printing apparatus is A seal cover that covers and seals the opening at the upper end of the heating funnel, and which is coupled opposite to the heating funnel, The system further includes a sealing gasket for sealing the space between the heating funnel and the sealing cover.

[0027] For example, the heating funnel includes a sealing flange formed along the outer edge of the inlet at the upper end, The seal gasket is interposed between the seal flanges of the heating funnels and the seal cover, which are joined facing each other by fastening means that penetrate the seal flanges of the heating funnels and the plate-shaped seal cover, which are formed side by side.

[0028] For example, the bidirectional pressure control unit is A first fluid tube extending from the common confluence point toward the heating funnel, A second fluid pipe connected to a positive pressure source from a common confluence point, It includes a third fluid pipe connected to a negative pressure source from a common confluence point.

[0029] For example, the bidirectional pressure control unit is On the first fluid pipe, a first fluid valve is connected between the common junction and the heating funnel, On the first fluid tube, a first pressure gauge is connected between the heating funnel and the first fluid valve, On the aforementioned second fluid pipe, a second fluid valve is connected between the common confluence point and the positive pressure source, On the second fluid tube, a second pressure gauge is connected between the positive pressure source and the second fluid valve, On the third fluid pipe, a third fluid valve is connected between the common confluence point and the negative pressure source, The third fluid pipe further includes a third pressure gauge connected between the negative pressure source and the third fluid valve.

[0030] For example, the bidirectional control unit is The system further includes a valve controller connected to each of the first to third fluid valves for applying control signals to each of the first to third fluid valves to control the opening and closing of the valves and the degree of opening.

[0031] For example, the valve controller is The first and second fluid valves are controlled to open so that the pressure difference between the inside and outside of the heating funnel is set to a positive pressure. The first and third fluid valves are controlled to open so that the pressure difference between the inside and outside of the heating funnel is set to a negative pressure.

[0032] For example, the multiphase three-dimensional printing apparatus is The system further includes a second discharge nozzle for dispensing a paste-like or slurry-like second material that forms the contour of the molded object. The width of the scan line forming the transfer path of the first ejection nozzle is set to scan the entire build area where the object is formed, which corresponds to the filling space surrounded by the contour of the object formed from the second material.

[0033] For example, the multiphase three-dimensional printing apparatus is The present invention further includes an extrusion device connected to the second discharge nozzle, which extrudes the second material toward the second discharge nozzle to discharge a paste-like or slurry-like second material which is a mixture of ceramic particles and a matrix in which ceramic particles are dispersed.

[0034] For example, the multiphase three-dimensional printing apparatus is The system further includes a heating chamber for providing a slow-cooling space for the first and second materials accumulated on the stage from the first and second discharge nozzles, while housing the stage. The pressure difference between the inside and outside of the heating funnel corresponds to the internal pressure of the heating funnel containing the liquid phase first material, with respect to the atmospheric pressure of the slow-cooling space of the heating chamber.

[0035] A multiphase three-dimensional printing apparatus according to a preferred embodiment of the present invention will be described below with reference to the attached drawings.

[0036] A multiphase 3D printing apparatus according to one embodiment of the present invention is A first discharge nozzle 10a for discharging a liquid phase first material M1 to form a molded object on the stage S, A heating funnel 10 to which the first discharge nozzle 10a is connected and which is filled with a liquid-phase first material M1, The heating funnel 10 is connected to a bidirectional pressure control unit 100 for alternatingly reversing the pressure difference PIO between the inside and outside of the heating funnel 10 between positive and negative pressure, and includes: i) a positive pressure to accelerate the flow of the first material M1 from the heating funnel 10 toward the first discharge nozzle 10a, and ii) a negative pressure to decelerate the flow of the first material M1 from the heating funnel 10 toward the first discharge nozzle 10a, or to brake the flow of the first material M1.

[0037] In one embodiment of the present invention, the bidirectional pressure control unit 100 is 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 discharge nozzle 10a.

[0038] In one embodiment of the present invention, the bidirectional pressure control unit 100 is The pressure difference PIO between the inside and outside of the heating funnel 10 is set to a negative pressure, and a suction force is provided toward the heating funnel 10 so that the flow of the first material M1 is not discharged from the heating funnel 10 toward the first discharge nozzle 10a.

[0039] In one embodiment of the present invention, the heating funnel 10 is From the upper inlet into which the metal block of the first material M1 is fed, to the bottleneck portion BN connected to the lower first discharge nozzle 10a from which the liquid phase of the first material M1 is discharged, the circumferential surface is wider at the top and narrower at the bottom, with the inner diameter gradually decreasing. With respect to the flow of the liquid phase of the first material M1, the fluid friction acting on the circumferential surface of the heated funnel 10 and the bottleneck portion BN that limits the flow rate of the first material M1 cause a pressure loss in the flow of the first material M1.

[0040] In one embodiment of the present invention, As the first material M1, which fills the inside of the heating funnel 10 with a limited capacity, is discharged from the inside of the heating funnel 10 onto the external stage S, the pressure loss caused in the flow of the first material M1 from the inside of the heating funnel 10 to the outside is reduced.

[0041] In one embodiment of the present invention, the bidirectional pressure control unit 100 is Under a steady-state condition in which the discharge rate of the first material M1 from the inside of the heating funnel 10 toward the external stage S is kept constant, i) To offset the pressure loss that decreases with the discharge of the first material M1, the pressure difference PIO inside and outside the heating funnel 10 decreases together, or ii) The discharge of the first material causes the decrease in the weight of the first material and the decrease in pressure loss, which act in opposing directions on the flow of the first material, to cancel each other out, so that the pressure difference between the inside and outside of the heating funnel is maintained equal. The pressure difference PIO inside and outside the heating funnel 10 is controlled.

[0042] In one embodiment of the present invention, the bidirectional pressure control unit 100 is The pressure difference PIO between the inside and outside of the heating funnel 10 is set to a positive pressure in order to offset the pressure loss caused in the flow of the first material M1 from the inside to the outside of the heating funnel 10. The pressure may be set to a decreasing positive pressure to offset the pressure loss that decreases with the discharge of the first material M1, or it may be set to a constant positive pressure while the decrease in the weight of the first material M1 and the decrease in pressure loss, which act in opposing ways on the flow of the first material M1, cancel each other out as the first material M1 is discharged.

[0043] In one embodiment of the present invention, the bidirectional pressure control unit 100 is Towards the heating funnel 10, gas GAS is injected, which accumulates inside the heating funnel 10 and forms the internal pressure PI of the heating funnel 10, thereby setting the pressure difference PIO between the inside and outside of the heating funnel 10 to a positive pressure, or, The gas GAS that accumulates inside the heating funnel 10 and forms the internal pressure PI of the heating funnel 10 is exhausted from the heating funnel 10, and the pressure difference PIO between the inside and outside of the heating funnel 10 is set to a negative pressure.

[0044] In one embodiment of the present invention, the bidirectional pressure control unit 100 is To maintain a steady-state discharge rate of the first material M1 from the inside of the heating funnel 10 toward the external stage S, a volumetric flow rate of gas GAS is provided that satisfies the volumetric volume of the discharged first material M1. i) Control the volumetric flow rate of gas GAS injected into the heating funnel 10 so as the pressure difference PIO between the inside and outside of the heating funnel 10 decreases to offset the pressure loss that decreases with the discharge of the first material M1, or, ii) As the first material M1 is discharged, the volumetric flow rate of the gas GAS injected into the heating funnel 10 is controlled so that the volumetric flow rate of the gas GAS is kept constant, while the decrease in the weight of the first material M1 and the decrease in pressure loss, which act in opposing directions on the flow of the first material M1, cancel each other out, and the pressure difference between the inside and outside of the heating funnel 10 is kept constant.

[0045] The following describes in more detail one aspect of a multiphase 3D printing apparatus according to one embodiment of the present invention.

[0046] In a multiphase 3D printing apparatus according to one embodiment of the present invention, a liquid phase first material M1 for forming the object itself is ejected from the heating funnel 10 onto the stage S by the pressure difference PIO between the inside and outside of the heating funnel 10. The pressure difference PIO between the inside and outside of the heating funnel 10 causes a positive pressure difference that acts as an extrusion force capable of forcibly pushing the liquid phase second material M2 filling the inside of the heating funnel 10 out of the heating funnel 10, and a negative pressure difference that acts as an attraction force capable of pulling the liquid phase first material M1, which is trying to be directed out of the heating funnel 10, inward into the heating funnel 10. As described later, in one embodiment of the present invention, the liquid phase first material M1 molten in the heating funnel 10 gradually shrinks in diameter from the inside of the heating funnel 10 due to the weight of the first material M1, forming a bottleneck portion BN with a minimum inner diameter that is connected to the first discharge nozzle 10a, thereby restricting the flow of the liquid phase first material M1. Furthermore, the circumferential surface of the heating funnel 10, which is formed in a shape that is wider at the top and narrower at the bottom, may cause flow friction on the flow of the liquid phase first material M1. Due to the resulting fluid friction, etc., the fluid resistance provides an appropriate pressing force that can force the flow of the first material M1 to continue flowing from the heating funnel 10 towards the first discharge nozzle 10a in order to counteract such fluid resistance. For example, in one embodiment of the present invention, the first material M1 housed in the heating funnel 10, along with the weight of the first material M1, is subjected to a pressure difference PIO between the inside and outside of the heating funnel 10 in which the first material M1 is housed, in order to shorten the cycle time of the molding process.

[0047] In other words, in one embodiment of the present invention, in order to shorten the cycle time required for forming a molded object, the flow rate of the liquid phase first material M1 flowing from the heating funnel 10 onto the stage S, or the discharge speed of the liquid phase first material M1 discharged onto the stage S from the first discharge nozzle 10a, can be maintained at a level above appropriate, and the pressure difference PIO between the inside and outside of the heating funnel 10, which acts as the pushing force of the first material M1 flowing from the heating funnel 10 onto the stage S, can be set to a positive pressure so as to maintain the flow rate of the liquid phase first material M1 flowing from the heating funnel 10 onto the stage S, or the discharge speed of the first material M1 discharged from the first discharge nozzle 10a, at an appropriate level higher than the flow rate of the liquid phase first material M1 flowing from the heating funnel 10 onto the stage S, or the discharge speed of the first material M1 discharged from the first discharge nozzle 10a, in accordance with the weight of the first material M1. For example, in one embodiment of the present invention, the flow rate of the first material M1 moving from the heating funnel 10 onto the stage S or the discharge rate of the first material M1 can be increased for the purpose of shortening the cycle time of the molding process of the molded object. The transfer speed of the first discharge nozzle 10a from which the first material M1 is discharged can be increased in accordance with the increased flow rate of the first material M1 or the discharge rate of the first material M1. By increasing the transfer speed of the first discharge nozzle 10a that scans the entire area where the molded object is formed (molding area), in other words, by increasing the coating volume V per unit time of the first material M1 that forms the molded object itself, the cycle time required to form the molded object or the cycle time to fill the set volume of the molded object can be shortened.

[0048] In one embodiment of the present invention, the heating funnel 10 from which the first material M1 is discharged gradually reduces in diameter from the inlet at the upper end, where a solid metal block is fed in as the raw material for the liquid phase first material M1, to the bottleneck portion BN connected to the first discharge nozzle 10a at the lower end. As the bottleneck portion BN connected to the first discharge nozzle 10a forms the smallest diameter, it can form a kind of flow resistance that limits the volumetric flow rate of the molten first material M1 inside the heating funnel 10, and despite pressure loss due to such flow resistance, In order to increase the volumetric flow rate of the first material M1 to an appropriate level (for example, to shorten the cycle time), rather than relying on the weight of the first material M1, in one embodiment of the present invention, in addition to the weight of the first material M1, the pressure difference PIO between the inside and outside of the heating funnel 10 containing the first material M1 can be controlled in both positive and negative directions, so as to provide control variables for the flow rate or discharge rate of the first material M1 while increasing the flow rate or discharge rate of the first material M1.

[0049] Throughout this specification, the pressure difference PIO between the inside and outside of the heating funnel 10 means 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), with respect to the pressure on the stage S that forms the outside of the heating funnel 10, i.e., the external pressure PO of the heating funnel 10 or the atmospheric pressure of 1 atm in the atmospheric environment that forms the outside of the heating funnel 10. In this sense, in one embodiment of the present invention, the pressure difference PIO between the inside and outside of the heating funnel 10 corresponds to the internal pressure PI of the heating funnel 10 relative to the external atmospheric pressure of 1 atm of the heating funnel 10, and can act as a pushing force that attempts to accelerate the flow of fluid from the inside of the heating funnel 10 toward the external stage S, or as an attractive force that attempts to decelerate or brake the flow of fluid from the inside of the heating funnel 10 toward the external stage S, with respect to the first material M1 of the liquid phase contained in the heating funnel 10.

[0050] In one embodiment of the present invention, a heating funnel 10 that supplies a liquid phase first material M1 onto a stage S via a first discharge nozzle 10a can form a bottleneck portion BN that forms the smallest inner diameter as the inner diameter gradually decreases from the upper inlet into which a solid phase metal block is fed as the raw material for the liquid phase first material M1 to the lower first discharge nozzle 10a, and the heating funnel 10 can be formed in a funnel shape that includes a circumferential surface with a decreasing inner diameter.

[0051] In one embodiment of the present invention, the flow of the liquid phase first material M1 from the heating funnel 10 toward the stage S is controlled by the pressure difference PIO between the inside and outside of the heating funnel 10, and is controlled by the pressure difference PIO between the inside and outside of the heating funnel 10, taking into account pressure losses due to the bottleneck portion BN of the heating funnel 10 which can act as a flow resistance to the flow of the material toward the stage S from the inside of the heating funnel 10 toward the outside, and flow friction acting on the circumferential surface of the heating funnel 10 which has a reduced inner diameter. For example, the liquid phase first material M1 molten inside the heating funnel 10 can form a flow of material discharged from the heating funnel 10 toward the stage S toward the outside, and such a flow of the first material M1 is accelerated or decelerated by the pressure difference PIO between the inside and outside of the heating funnel 10, and in one embodiment of the present invention, the flow of the first material M1 may also be braked by the pressure difference PIO between the inside and outside of the heating funnel 10.

[0052] In one embodiment of the present invention, the pressure difference PIO between the inside and outside of the heating funnel 10 is calculated using the internal pressure PI of the heating funnel 10, which is obtained by subtracting the external pressure PO (atmospheric pressure, 1 atm) of the heating funnel 10 from the external pressure PO (atmospheric pressure, 1 atm) of the heating funnel 10. At this time, the pressure difference PIO between the inside and outside of the heating funnel 10 is controlled in both positive and negative directions. More specifically, in accordance with the internal pressure PI of the heating funnel 10, which is fluidly connected to the bidirectional pressure control unit 100, the internal pressure PI of the heating funnel 10 is formed to be higher than the external pressure PO of the heating funnel 10, and from the pressure difference PIO between the inside and outside of the heating funnel 10, that is, as the pressure difference PIO between the inside and outside of the heating funnel 10, the positive pressure of the heating funnel The flow of the liquid phase first material M1 contained in 10 may be accelerated to increase the flow velocity, or conversely, as the internal pressure PI of the heating funnel 10, which is fluidly connected to the bidirectional pressure control unit 100, forms a pressure difference PIO between the inside and outside of the heating funnel 10 that is negative, the flow velocity of the flow of the first material M1 contained in the heating funnel 10 may be reduced, or the flow velocity of the flow of the first material M1 may be braked while making the flow velocity of the flow of the first material M1 substantially zero or negative.

[0053] In one embodiment of the present invention, the internal pressure PI of the heating funnel 10 can be increased or decreased from a bidirectional pressure control unit 100 that is fluidly connected to the heating funnel 10. This allows the internal pressure PI of the heating funnel 10 to be set as positive or negative pressure relative to atmospheric pressure, with respect to the external pressure PO of the heating funnel 10. More specifically, the internal pressure PI of the heating funnel 10 can be increased or decreased by controlling the injection or exhaust of gas GAS that accumulates in the heating funnel 10 and forms the internal pressure PI of the heating funnel 10 in real time. Based on the internal pressure PI of the heating funnel 10 or the external pressure PO of the heating funnel 10 under constant atmospheric pressure, the internal pressure PI of the heating funnel 10 or the pressure difference PIO between the inside and outside of the heating funnel 10 can be used to control the heating funnel The flow of the molten first material M1 inside the funnel 10 can be accelerated or decelerated to increase or decrease its flow velocity. For example, by injecting gas GAS into the heating funnel 10 so that it accumulates inside the heating funnel 10 and forms an internal pressure PI, a positive pressure can be formed between the inside and outside of the heating funnel 10. This can be used to accelerate the flow of the first material M1 discharged from the inside to the outside of the heating funnel 10, thereby increasing its flow velocity. Conversely, by exhausting the gas GAS from the heating funnel 10 where an internal pressure PI has been formed by the gas GAS accumulated inside the heating funnel 10, a negative pressure difference can be formed between the inside and outside of the heating funnel 10. This can be used to decelerate the flow of the first material M1 discharged from the inside to the outside of the heating funnel 10, thereby decreasing its flow velocity.

[0054] In one embodiment of the present invention, as the first material M1 is discharged from the heating funnel 10, which is filled with a certain amount of the first material M1, onto a stage S outside the heating funnel 10, the amount of the first material M1 filling the heating funnel 10 decreases over time, and gas GAS is injected toward the heating funnel 10 to fill the empty space occupied by the first material M1 within the heating funnel 10. Even if gas GAS is injected toward the interior of the heating funnel 10 from a bidirectional pressure control unit 100, as long as it fills the empty space inside the heating funnel 10 formed by the discharge of the first material M1, the injection of gas GAS toward the interior of the heating funnel 10 may not form an accumulation of gas GAS inside the heating funnel 10, or it may not generate an increase in the internal pressure PI of the heating funnel 10 due to the accumulation of gas GAS, or an acceleration of the metallic flow of the first material M1 due to the increase in the internal pressure PI of the heating funnel 10.

[0055] In one embodiment of the present invention, the pressure difference PIO between the inside and outside of the heating funnel 10 can realize an acceleration of the flow of the first material M1 from inside the heating funnel 10 toward the stage S outside the heating funnel 10 (e.g., an increase in flow velocity), and the injection of gas GAS into the heating funnel 10 to accelerate the flow induces an increase in the internal pressure PI due to the accumulation of gas GAS inside the heating funnel 10. In one embodiment of the present invention, the internal pressure PI of the heating funnel 10 is formed from the accumulation of gas GAS and substances such as the first material M1 accumulated inside the heating funnel 10. In one embodiment of the present invention, under the operating environment of the heating funnel 10 in which the first material M1 is discharged from the heating funnel 10 filled with a limited capacity, the amount of substance to be replenished to the extent that gas GAS is replenished may not accumulate to fill the inside of the heating funnel 10. For example, injecting gas GAS into the heating funnel 10 may not lead to an increase in the internal pressure PI of the heating funnel 10 due to the accumulation of substance. More specifically, if the amount of gas GAS injected into the heating funnel 10 per unit time is equal to the amount of first material M1 discharged from the heating funnel 10 per unit time, then, for example, while the volume of material filling the inside of the heating funnel 10, such as the volume of gas GAS and first material M1, remains the same, the internal pressure PI of the heating funnel 10 does not increase despite the injection of gas GAS. As a result, flow acceleration, which increases the flow velocity of the metallic flow of first material M1 from inside the heating funnel 10 towards the stage S outside the heating funnel 10, may not be realized.

[0056] In one embodiment of the present invention, as the first material M1 is discharged from inside the heating funnel 10, which is filled with a certain amount of the first material M1, onto a stage S outside the heating funnel 10, a bidirectional pressure control unit 100, which is fluidly connected to the heating funnel 10, can supply gas GAS of a volume sufficient to fill the empty space created by the discharge of the first material M1 to the heating funnel 10. For example, considering the discharge rate of the first material M1 that escapes from the heating funnel 10 per unit time, it is possible to provide a gas GAS volume flow rate that can supply gas GAS of a volume sufficient to fill the volume of the discharged first material M1.

[0057] In one embodiment of the present invention, a heating funnel 10 filled with a liquid-phase first material M1 may include a bottleneck portion BN connected to a first discharge nozzle 10a that discharges the liquid-phase first material M1 from the heating funnel 10 onto a stage S, and may include a circumferential surface that is wider at the top and narrower at the bottom, with the inner diameter gradually decreasing from the inlet at the top end into which a solid-phase metal block of the first material M1 is fed to the first discharge nozzle 10a at the bottom from which the liquid-phase first material M1 is discharged, and the flow of the liquid-phase first material M1 flowing along such a circumferential surface may experience flow friction on the circumferential surface, for example, a boundary layer on the circumferential surface where the liquid-phase first material M1 is stagnant A boundary layer is formed, and due to viscosity or cohesive forces between particles forming the first material M1 between this boundary layer and the flow of the first material M1 flowing along the boundary layer, the flow of the first material M1 can experience pressure loss due to flow friction. Along with the pressure loss due to flow friction, a bottleneck portion BN that can substantially limit the amount of first material M1 discharged from the inside of the heating funnel 10 onto the external stage S also causes pressure loss, and as the liquid phase of the first material M1 thus flows from the inside of the heating funnel 10 To compensate for the pressure loss experienced during the discharge process of the first material M1 onto the external stage S, the pressure difference PIO between the inside and outside of the heating funnel 10 is set to a positive pressure. Considering that the flow of the first material M1 can be accelerated to a higher flow velocity by subtracting the pressure loss from the pressure difference PIO between the inside and outside of the heating funnel 10, which is set to a positive pressure, the pressure difference PIO between the inside and outside of the heating funnel 10 can be set to a positive pressure that exceeds the pressure loss in order to accelerate the flow velocity of the flow of the first material M1.

[0058] In one embodiment of the present invention, if the pressure difference PIO between the inside and outside of the heating funnel 10 is set to a level equivalent to the pressure loss, the metallic flow of the first material M1 filling the inside of the heating funnel 10 can be discharged onto the stage S at a constant discharge rate via the first discharge unit while maintaining a constant flow rate. In other words, if the pressure difference PIO between the inside and outside of the heating funnel 10 is kept at a level equivalent to the pressure loss, the discharge amount of the liquid phase first material M1 supplied from the inside of the heating funnel 10 onto the external stage S can be kept constant.

[0059] In one embodiment of the present invention, considering a driving environment for a heating funnel 10 in which a limited volume of liquid-phase first material M1 is gradually discharged onto a stage S via a first discharge nozzle 10a, the pressure loss (or flow resistance) caused by the flow of the liquid-phase first material M1 discharged from the heating funnel 10 onto the external stage S decreases along the time axis. More specifically, the pressure loss (or flow resistance) caused by the flow of the heating funnel 10 may include a flow friction component caused on the top-wide, bottom-narrow circumferential surface of the heating funnel 10 as its inner diameter decreases. As the amount of the first material M1 contained in the heating funnel 10 decreases along the time axis due to the discharge of the first material M1, the contact area with the top-wide, bottom-narrow circumferential surface of the heating funnel 10 gradually decreases. As this decrease in the contact area between the first material M1 and the circumferential surface of the heating funnel 10 reduces the flow friction, which is correlated with the contact area of ​​the heating funnel 10, the pressure loss (or flow resistance) decreases. In one embodiment of the present invention, as liquid-phase first material M1 is discharged from inside a heating funnel 10 filled with a certain volume of first material M1 onto an external stage S, the volume of first material M1 inside the heating funnel 10 decreases, and the contact area between the first material M1 and the circumferential surface of the heating funnel 10 filled with the first material M1 decreases. As the contact area decreases, the pressure loss due to frictional flow (flow resistance) decreases.

[0060] In one embodiment of the present invention, under a steady-state driving environment in which the discharge rate of the first material M1 from the inside of the heating funnel 10 onto the external stage S is kept constant, the discharge rate of the liquid phase first material M1 or the flow velocity of the liquid phase first material M1 is kept constant. In order to keep the flow velocity of the liquid phase first material M1 constant, the pressure difference PIO between the inside and outside of the heating funnel 10, which forms a positive pressure to offset the pressure loss, also decreases in accordance with the pressure loss (flow resistance) that decreases along the time axis. In other words, 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 with respect to the external pressure PO (atmospheric pressure, 1 atm) of the heating funnel 10, which is maintained at a constant atmospheric pressure. In various embodiments of the present invention, as the amount of first material M1 contained inside the heating funnel 10 gradually decreases over time, the contact area between the first material M1 and the circumferential surface of the heating funnel 10 that forms the frictional flow decreases, reducing the flow resistance or pressure loss. Along with this, the decrease in the weight of the first material M1, which decreases in accordance with the decrease in the amount of first material M1 contained inside the heating funnel 10, cancels out the decrease in the flow resistance of the first material M1, which can promote the flow of the first material M1 from inside the heating funnel 10 onto the stage S outside the heating funnel 10. In this way, the pressure difference PIO between the inside and outside of the heating funnel 10 that forms the steady state can be maintained at a constant level.

[0061] In one embodiment of the present invention, a bidirectional pressure control unit 100 for supplying gas GAS into the interior of a heating funnel 10 to offset pressure losses caused in the flow of a first material M1 from the interior of the heating funnel 10 onto a stage S, injects gas GAS into the interior of the heating funnel 10 such that the pressure difference PIO between the interior and exterior of the heating funnel 10 is set to a positive pressure in order to offset the pressure losses. However, the flow rate of gas GAS injected per unit time, for example, the volumetric flow rate of injected gas GAS, can be reduced so that the internal pressure PI of the heating funnel 10 also decreases in accordance with the pressure losses that decrease along the time axis. In 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 and the decrease in the flow resistance of the first material M1, which act in opposite directions to the flow of the first material M1, cancel each other out. As a result, the pressure difference PIO inside and outside the heating funnel 10 for maintaining a steady state flow of the first material M1 is maintained at a constant level. For this purpose, a bidirectional pressure control unit 100 connected to the heating funnel 10 can maintain the flow rate of the gas GAS directed toward the heating funnel 10, for example, the volumetric flow rate of the injected gas GAS, at a constant level.

[0062] In one embodiment of the present invention, under a steady-state driving environment in which the discharge rate of the first material M1 discharged from the inside of the heating funnel 10 onto the external stage S is kept constant, the volume of the first material M1 injected into the inside of the heating funnel 10 per unit time is kept constant. For example, a bidirectional pressure control unit 100, which is fluidly connected to the inside of the heating funnel 10, can inject a volume of gas GAS into the inside of the heating funnel 10 that corresponds to the volume of the first material M1 discharged from the heating funnel 10 per unit time, so as to fill the empty space with a volume equal to the volume discharged from the heating funnel 10 per unit time. Under the control of such a bidirectional pressure control unit 100, the internal pressure PI of the heating funnel 10, which has accumulated the same volume of material without a change in the volume of material filling the heating funnel 10, can be kept constant. As described above, as the liquid phase first material M1, which is filled to a limited capacity by the melting of the metal block introduced into the heating funnel 10, is discharged from the inside of the heating funnel 10 onto the external stage S, the pressure loss (flow resistance) caused by the flow of the first material M1 from the inside to the outside of the heating funnel 10 decreases. In accordance with this, the internal pressure PI of the heating funnel 10, which is used to offset the decreasing pressure loss (flow resistance), also decreases. Thus, in one embodiment of the present invention, the flow rate of gas GAS injected into the heating funnel 10 per unit time, for example, the volumetric flow rate corresponding to the volumetric volume injected into the heating funnel 10 per unit time, can also be controlled by a profile that decreases along the time axis.

[0063] In one embodiment of the present invention, a bidirectional pressure control unit 100, which is fluidically connected to the heating funnel 10, can inject gas GAS into the heating funnel 10 at a constant volume flow rate equal to the volume volume of the first material M1 that escapes from the heating funnel 10 to the outside of the heating funnel 10 at a constant volume per unit time in a steady-state driving environment that embodies the discharge of a first material M1 from the inside of the heating funnel 10 to the outside of the heating funnel 10 at a constant volume per unit time, and the internal pressure PI of the heating funnel 10 is kept constant while the material is filled to a constant volume. In one embodiment of the present invention, the internal pressure PI of the heating funnel 10 decreases along the time axis in proportion to the pressure loss that decreases along the time axis, and for this reason, the flow rate of gas GAS injected into the heating funnel 10 per unit time, for example, the volume flow rate of gas GAS corresponding to the volume volume injected into the heating funnel 10 per unit time, decreases along the time axis.

[0064] In various embodiments of the present invention, as the amount of first material M1 contained in the heating funnel 10 decreases, the decrease in the self-weight of the first material M1 and the decrease in the flow resistance of the first material M1, which act in opposing directions to the flow of the first material M1, cancel each other out, forming a steady state flow of the first material M1. The pressure difference PIO between the inside and outside of the heating funnel 10 can be kept constant, and the flow rate of gas GAS supplied into the heating funnel 10, for example, the volume per unit time of gas GAS supplied into the heating funnel 10, can be kept constant.

[0065] In one embodiment of the present invention, a bidirectional pressure control unit 100 connected to the heating funnel 10 for controlling the internal pressure PI of the heating funnel 10 controls 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 exhausting a gas GAS that is accumulated inside the heating funnel 10 and forms the internal pressure PI. At this time, the gas GAS whose injection into and exhaust from the bidirectional pressure control unit 100 is controlled is formed as a compressible gas GAS or an incompressible gas GAS (Mach number 0.3 or less). For example, in one embodiment of the present invention, the gas GAS whose inflow and outflow from the bidirectional pressure control unit 100 is controlled, is compressible, and its density changes with pressure. For example, in one embodiment of the present invention, the volumetric flow rate of the gas GAS injected into the heating funnel 10 decreases along the time axis, corresponding to the pressure loss (flow resistance) as the internal pressure PI of the heating funnel 10 decreases along the time axis. Thus, the decrease in the volumetric flow rate of the gas GAS injected per unit time along the time axis is understood to be based on the assumption of an incompressible gas GAS in which the volumetric volume of the gas GAS injected per unit time along the time axis is kept constant, while its density does not change with changes in the internal pressure PI of the heating funnel 10. Furthermore, in various embodiments of the present invention, incompressible gas GAS, which is injected and exhausted by a bidirectional pressure control unit 100, can be supplied to the heating funnel 10 at a constant gas flow rate or a constant volume of gas per unit time, while the decrease in pressure loss or flow resistance and the decrease in the weight of the first material M1 cancel each other out, acting in a mutually opposing manner on the flow of the first material M1 as the amount of first material M1 contained in the heating funnel 10 decreases over time.

[0066] In various embodiments of the present invention, the inflow and outflow of the heating funnel 10 are controlled via the bidirectional pressure control unit 100, and the gas GAS for controlling the internal pressure PI of the heating funnel 10 can include a variety of compressible and incompressible gases, and can include any fluid that can accumulate inside the heating funnel 10 and form the internal pressure PI of the heating funnel 10 as a fluid encompassing both gas and liquid phases, and may include a gas- and liquid-phase mixed fluid including, for example, a gas-phase matrix gas containing a liquid phase component such as water vapor.

[0067] In various embodiments of the present invention, the gas GAS whose inflow and outflow to the heating funnel 10 is controlled so as to control the internal pressure PI of the heating funnel 10 from a bidirectional pressure control unit 100 connected to the heating funnel 10 may include a compressible gas GAS whose density or volume changes with a predetermined pressure. In one embodiment of the present invention, under a steady-state driving environment in which the discharge rate of the liquid phase first material M1 is kept constant, in response to the decrease in pressure loss such as flow friction caused on the upper-wide, lower-narrow circumferential surface of the heating funnel 10 as the first material M1 is discharged, the internal pressure PI of the heating funnel 10 under the control of the bidirectional pressure control unit 100 decreases or is maintained at a constant level. At this time, the gas GAS injected into the heating funnel 10 to decrease or maintain the internal pressure PI of the heating funnel 10 is The flow rate, for example, the volumetric flow rate of gas GAS corresponding to the volumetric volume injected into the heating funnel 10 per unit time, may show a relatively smaller and gentler rate of decrease compared to incompressible gas GAS, considering the density increase and volumetric compression of compressible gas GAS due to the pressure of the heating funnel 10, based on the density change or volumetric change characteristics of compressible gas GAS. Alternatively, considering the density change or volumetric change characteristics of compressible gas GAS filling the empty space caused by the void in the first material M1 due to the discharge of the incompressible first material M1, the operation of the bidirectional pressure control unit 100 connected to the heating funnel 10 may be controlled to follow a profile in which the volumetric flow rate of gas GAS increases along the time axis.

[0068] In summary, the pressure loss due to flow resistance or flow friction caused by the flow of the liquid phase first material M1 discharged from the inside of the heating funnel 10 onto the external stage S is gradually reduced along the time axis as the contact area between the first material M1 and the circumferential surface of the heating funnel 10, which is wider at the top and narrower at the bottom, decreases within the heating funnel 10 filled with a limited capacity of the first material M1. At this time, in a steady-state driving environment in which the discharge amount of the second material M2 from the inside of the heating funnel 10 onto the external stage S is kept constant, in order to maintain a constant flow velocity of the first material M1 by offsetting the pressure loss that decreases along the time axis, the internal pressure PI of the heating funnel 10 also decreases along the time axis, or the internal pressure PI of the heating funnel 10 can be maintained at a constant level along the time axis by considering the offsetting of the pressure loss or flow resistance that decreases in accordance with the amount of the first material M1 that decreases over time and the weight of the first material M1.

[0069] In various embodiments of the present invention, the operation of a bidirectional pressure control unit 100, which is fluidically connected to the heating funnel 10, can be controlled to embody the steady-state driving environment described above, that is, to follow the profile 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 the bidirectional pressure control unit 100 may also increase or decrease along the time axis the volumetric flow rate of gas GAS corresponding to the volumetric volume injected into the heating funnel 10 per unit time, due to the compressibility of the gas GAS injected into the heating funnel 10. For example, in one embodiment of the present invention, if the gas GAS or fluid injected into the heating funnel 10 is a compressible gas GAS, the relative proportion of the material filling the heating funnel 10 while replenishing the gaps of the second material M2 that escape from the heating funnel 10 per unit time under a steady-state driving environment changes from a relatively high proportion of incompressible material (second material M2) and a low proportion of compressible material (compressible gas GAS) to a relatively low proportion of incompressible material (second material M2) and a high proportion of compressible material (compressible gas GAS) along the time axis, and the flow rate of the gas GAS in an uncompressible or insufficiently compressed state, for example, the volumetric flow rate of compressible gas GAS corresponding to the volumetric volume per unit time, increases so that the pressure of the gas GAS compressed to an equivalent level is applied to the interface between the compressible material (compressible gas GAS) which occupies a relatively high proportion and the second material M2. However, the volumetric flow rate of the compressible gas GAS injected into the heating funnel 10 can be understood to decrease or remain constant along the time axis, depending on the measurement location of the volumetric flow rate. For example, at measurement locations where the internal pressure PI of the heating funnel 10 can be transmitted, the compressible gas GAS may be measured in a state where it is substantially compressed by the internal pressure PI of the heating funnel 10.

[0070] In one embodiment of the present invention, if the gas GAS or fluid injected into the heating funnel 10 is incompressible or considered incompressible, such incompressible gas GAS (or fluid) can form the internal pressure PI of the heating funnel 10 while the inside of the heating funnel 10 is filled with incompressible material, even if the relative ratio of the first material M1 and the gas GAS changes along the time axis. Thus, the volumetric flow rate of the incompressible gas GAS can decrease or be maintained along the time axis.

[0071] In one embodiment of the present invention, the bidirectional pressure control unit 100 is A first fluid tube 110 extends from the common confluence point COM toward the heating funnel 10, A second fluid pipe 120 is connected from the common confluence point COM to the positive pressure source PS, It includes a third fluid pipe 130 connected from a common confluence point COM to a negative pressure source NS.

[0072] In one embodiment of the present invention, the bidirectional pressure control unit 100 is On the first fluid pipe 110, a first fluid valve 111 is connected between the common junction COM and the heating funnel 10, On the second fluid pipe 120, a second fluid valve 121 is connected between the common junction COM and the positive pressure source PS, The system includes a third fluid valve 131 connected on the third fluid pipe 130 between the common junction COM and the negative pressure source NS.

[0073] In one embodiment of the present invention, the bidirectional pressure control unit 100 is The system includes a valve controller 150 connected to each of the first to third fluid valves 111, 121, and 131, for applying 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 degree of opening.

[0074] In one embodiment of the present invention, the valve controller 150 is The first and second fluid valves 111 and 121 are controlled to open so that the pressure difference PIO inside and outside the heating funnel 10 is set to a positive pressure. The first and third fluid valves 111 and 131 are controlled to open so that the pressure difference PIO inside and outside the heating funnel 10 is set to a negative pressure.

[0075] In one embodiment of the present invention, the valve controller 150 is The first fluid valve 111 can be kept open, and the second and third fluid valves 121 and 131, which are connected to the positive pressure source PS and the negative pressure source NS respectively, can be controlled to alternately open and close the second and third fluid valves 121 and 131, respectively, while the first fluid valve 111 is open, so as to alternately reverse the pressure difference PIO between the inside and outside of the heating funnel 10 between positive pressure and negative pressure.

[0076] For example, the valve controller 150 is 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 to be staggered relative to each other.

[0077] In one embodiment of the present invention, the bidirectional pressure control unit 100 is On the first fluid tube 110, a first pressure gauge 115 is connected between the heating funnel 10 and the first fluid valve 111, On the second fluid pipe 120, a second pressure gauge 125 is connected between the positive pressure source PS and the second fluid valve 121, The system includes a third pressure gauge 135 connected between the negative pressure source NS and the third fluid valve 131 on the third fluid pipe 130.

[0078] In one embodiment of the present invention, the first pressure gauge 115 measures the internal pressure PI of the heating funnel 10, The second and third pressure gauges 125 and 135 can measure the pressure of the positive pressure source PS and the negative pressure source NS, respectively.

[0079] A multiphase 3D printing apparatus according to one embodiment of the present invention is The width w of the scan line SL that forms the transfer path of the first discharge nozzle 10a and the coating volume V per unit time are calculated according to the scan speed per unit time which corresponds to the transfer speed. The system includes a control unit 151 for setting the pressure difference PIO inside and outside the heating funnel 10 to a positive pressure in order to accelerate the flow of the liquid phase first material M1, or to decelerate the flow of the liquid phase first material M1, or to brake the flow of the liquid phase first material M1, in accordance with the calculated coating volume V per unit time. The valve controller 150 can control the opening and closing and degree of the first to third fluid valves 111, 121, and 131 so that the internal pressure PI value measured from 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.

[0080] The following describes one aspect of a multiphase 3D printing apparatus according to one embodiment of the present invention.

[0081] In one embodiment of the present invention, a bidirectional pressure control unit 100 fluidically connected to the heating funnel 10 includes a branch (corresponding to a second fluid pipe 120) connected to a positive pressure source PS to generate a pressure difference PIO between the inside and outside of the heating funnel 10 with positive pressure relative to the heating funnel 10, a branch (corresponding to a third fluid pipe 130) connected to a negative pressure source NS to generate a pressure difference PIO between the inside and outside of the heating funnel 10 with negative pressure relative to the heating funnel 10, and a common connection between the positive pressure source PS and the negative pressure source NS. The structure is formed such that a total of three branches (corresponding to the first to third fluid pipes 130) extending from the confluence position COM toward the heating funnel 10 (corresponding to the first fluid pipe 110) are connected to each other at the common confluence position COM. More specifically, it includes 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.

[0082] In one embodiment of the present invention, the bidirectional pressure control unit 100 can provide positive pressure to the heating funnel 10 via a common confluence position COM and the first fluid pipe 110 connected to the second fluid pipe 120 by opening the second fluid pipe 120 connected to the positive pressure source PS, or by controlling the opening degree of the opened second fluid pipe 120. Conversely, the bidirectional pressure control unit 100 can provide negative pressure to the heating funnel 10 via a common confluence position COM and the first fluid pipe 110 connected to the third fluid pipe 130 by opening the third fluid pipe 130 connected to the negative pressure source NS, or by controlling the opening degree of the opened third fluid pipe 130.

[0083] In one embodiment of the present invention, providing positive pressure to the heating funnel 10 means creating positive pressure inside and outside the heating funnel 10 (for example, internal pressure PI > external pressure PO) to accelerate the flow of the liquid phase first material M1 discharged from inside the heating funnel 10 onto the external stage S, or driving a constant velocity flow or steady-state by subtracting the pressure loss caused by the flow of the first material M1 from the pressure difference PIO (positive pressure) inside and outside the heating funnel 10.

[0084] In one embodiment of the present invention, providing negative pressure to the heating funnel 10 means creating negative pressure inside and outside the heating funnel 10 (for example, internal pressure PI of the heating funnel 10 < external pressure PO of the heating funnel 10) to slow down the flow of the liquid phase first material M1 discharged from inside the heating funnel 10 onto the external stage S. For example, in one embodiment of the present invention, the flow of liquid-phase first material M1 discharged from inside the heating funnel 10 onto an external stage S can also be braked (for example, forming a flow velocity substantially zero or negative - a negative flow velocity for the flow of the first material M1 from the first discharge nozzle 10a towards the inside of the heating funnel 10), for example, the flow of the first material M1 obtained from the previous positive pressure can be slowed down, for example, to stop the flow of the first material M1, or conversely to provide a negative flow velocity for the flow of the first material M1, thereby reversing the flow direction so that the metallic flow of the first material M1 is directed in a negative direction from the first discharge unit towards the heating funnel 10. In one embodiment of the present invention, the bidirectional pressure control unit 100 can provide a pushing force from the inside of the heating funnel 10 to the external stage S from a positive pressure, or brake the flow of fluid from the inside of the heating funnel 10 to the external stage S, or provide a suction force for a reversed flow of fluid from the external stage S to the inside of the heating funnel 10.

[0085] In one embodiment of the present invention, the bidirectional pressure control unit 100 includes a first fluid valve 111 connected between a common confluence position COM and a heating funnel 10, a second fluid valve 121 connected between the common confluence position COM and a positive pressure source PS, and a third fluid valve 131 connected between the common confluence position COM and a negative pressure source NS, and further includes a valve controller 150 connected to each of the first to third fluid valves 111, 121, and 131 for applying control signals to each of the first to third fluid valves 111, 121, and 131 to control the opening and closing and angle of the valves. For example, in one embodiment of the present invention, the valve controller 150 controls the opening of the first and second fluid valves 111 and 121 so as to set the pressure difference PIO inside and outside the heating funnel 10 to a positive pressure, and controls the opening of the first and third fluid valves 111 and 131 so as to set the pressure difference PIO inside and outside the heating funnel 10 to a negative pressure. For example, in one embodiment of the present invention, the valve controller 150 can control the first to third fluid valves 111, 121, and 131, respectively, to alternately open and close the second and third fluid valves 121 and 131, which are connected to the positive pressure source PS and the negative pressure source NS, while the first fluid valve 111 is open, so as to alternately reverse the pressure difference PIO between the inside and outside of the heating funnel 10 between positive pressure and negative pressure. 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 so as to be staggered relative to each other.

[0086] In one embodiment of the present invention, the bidirectional pressure control unit 100 includes fluid equipment for outputting a mechanical pressure difference from an electrical input, as a positive pressure source PS and a negative pressure source NS, each including a fluid equipment with a low-pressure inlet and a high-pressure outlet. For example, in 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 includes a compressor for injecting gas GAS at high pressure toward the heating funnel 10 via the high-pressure outlet, and the negative pressure source NS connected to the third fluid pipe 130 of the bidirectional pressure control unit 100 includes a vacuum pump for exhausting gas GAS at low pressure from the heating funnel 10 via the low-pressure inlet. In various embodiments of the present invention, the positive pressure sources PS connected to the second fluid tube 120 are set to a pressure higher than the internal pressure PI of the heating funnel 10 and include high-pressure storage tanks that can inject gas GAS into the heating funnel 10 at high pressure depending on the opening and closing of the second fluid valve 121 for intermittently connecting the second fluid tube 120, while the negative pressure sources NS connected to the third fluid tube 130 are set to a pressure lower than the internal pressure PI of the heating funnel 10 and include low-pressure storage tanks that can exhaust gas GAS from the heating funnel 10 at low pressure depending on the opening and closing of the third fluid valve 131 for intermittently connecting the third fluid tube 130.

[0087] In 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 in response to the opening of a second fluid valve 121 for intermittently connecting a second fluid pipe 120 connected to a 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 in response to the opening of a third fluid valve 131 for intermittently connecting a third fluid pipe 130 connected to a negative pressure source NS. More specifically, in controlling the bidirectional pressure control unit 100 to set the pressure difference PIO between the inside and outside of the heating funnel 10 to a positive or negative pressure, the intermittent connection of the second fluid pipe 120 connected to the positive pressure source PS and the intermittent connection of the third fluid pipe 130 connected to the negative pressure source NS can be controlled to be staggered from one another. For example, in controlling the bidirectional pressure control unit 100 to set the pressure difference PIO between the inside and outside of the heating funnel 10 to a positive pressure, the second fluid pipe 120 connected to the positive pressure source PS The connection of the main tube 120 (opening of the second fluid valve 121) is performed simultaneously with the shutting off of the third fluid tube 130 connected to the negative pressure source NS (shutting off the third fluid valve 131). Conversely, in the control of the bidirectional pressure control unit 100 for setting the pressure difference PIO inside and outside the heating funnel 10 to negative pressure, the connection of the third fluid tube 130 connected to the negative pressure source NS (opening of the third fluid valve 131) and the shutting off of the second fluid tube 120 connected to the positive pressure source PS (shutting off the second fluid valve 121) can be performed simultaneously. Furthermore, for setting the pressure of the heating funnel 10 by the bidirectional pressure control unit 100, that is, for both control to set the pressure difference PIO between the inside and outside of the heating funnel 10 to positive pressure and control to set the pressure difference PIO between the inside and outside of the heating funnel 10 to negative pressure, pressure can be transmitted from the positive pressure source PS and the negative pressure source NS to the heating funnel 10 by connecting the first fluid pipe 110. More specifically, in the control to set the pressure difference PIO between the inside and outside of the heating funnel 10 to positive pressure, the positive pressure source PS and the heating funnel 10 are fluidically connected to each other by connecting the second fluid pipe 120 connected to the positive pressure source PS and the first fluid pipe 110, and for this reason, both the first fluid valve 111 that intermittently opens the first fluid pipe 110 and the second fluid valve 121 that intermittently opens the second fluid pipe 120 can be opened.On the other hand, in controlling the heating funnel 10 to a negative pressure, the negative pressure source NS and the heating funnel 10 are fluidly connected to each other by connecting the third fluid pipe 130, which is connected to the negative pressure source NS, and the first fluid pipe 110. As a result, both the first fluid valve 111, which intermittently opens the first fluid pipe 110, and the third fluid valve 131, which intermittently opens the third fluid pipe 130, can be opened. In other words, in one embodiment of the present invention, in order to precisely control the flow of the first material M1 from the heating funnel 10 onto the stage S, for example, the flow of the first material M1 needs to be precisely controlled to satisfy without excess or deficiency the coating volume V per unit time, which can be set from the transfer path (e.g., the width w of the scan line SL forming the transfer path) and the transfer speed (e.g., the length L of the scan line SL per unit time corresponding to the transfer speed) of the first discharge nozzle 10a for discharging the flow of the first material M1. For this purpose, in one embodiment of the present invention, the bidirectional pressure control unit 100 controls the inside and outside of the heating funnel 10. The pressure difference PIO can be alternately reversed between positive and negative pressure, and in this case, the valve controller 150 for controlling the opening and closing of the first to third fluid valves 111, 121, and 131 can control the opening and closing of the first to third fluid valves 111, 121, and 131 so that the first fluid valve 111 for controlling the intermittence of the first fluid pipe 110 for connection of the first fluid pipe 110 is open, and the second fluid valve 121 for intermittence of the second fluid pipe 120 connected to the positive pressure source PS and the third fluid valve 131 for intermittence of the third fluid pipe 130 connected to the negative pressure source NS open and close alternately with each other. For example, in one embodiment of the present invention, a valve controller 150 for controlling the opening and closing of the first to third fluid valves 111, 121, and 131 can control the opening and closing of the first to third fluid valves 111, 121, and 131 so that the pressure difference PIO between the inside and outside of the heating funnel 10 alternately reverses between positive and negative pressure, and the opening and closing of the second and third fluid valves 121 and 131 are repeated in conjunction with the opening of the first fluid valve 111.

[0088] In one embodiment of the present invention, the bidirectional pressure control unit 100 includes a first pressure gauge 115 connected between the heating funnel 10 and a first fluid valve 111, a second pressure gauge 125 connected between a positive pressure source PS and a second fluid valve 121, and a third pressure gauge 135 connected between the negative pressure source NS and a third fluid valve 131, wherein the bidirectional pressure control unit 100 receives 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 from the first to third pressure gauges 135, respectively. The pressure is measured, and by closing the first to third fluid valves 111, 121, and 131 adjacent to the first to third pressure gauges 135, for example, by closing the first fluid valve 111, the first pressure gauge 115 can measure the internal pressure PI of the heating funnel 10; by closing the second fluid valve 121, the second pressure gauge 125 can measure the pressure of the positive pressure source PS; and by closing the third fluid valve 131, the third pressure gauge 135 can measure the pressure of the negative source.For example, in one embodiment of the present invention, the first pressure gauge 115 is connected on the first fluid tube 110 between the heating funnel 10 and the first fluid valve 111 and can measure the internal pressure PI of the heating funnel 10 (e.g., when the first fluid valve 111 is closed) or the flow pressure of the gas GAS on the first fluid tube 110 (e.g., when the first fluid valve 111 is open) depending on the opening and closing of the first fluid valve 111, and comprehensively, considering that the flow velocity of the gas GAS is limited, the first pressure gauge 115 is understood to measure the internal pressure PI of the heating funnel 10, and the second pressure gauge 125 is connected on the second fluid tube 120 between the positive pressure source PS and the second fluid valve 121 and can measure the pressure of the positive pressure source PS (e.g., when the second fluid valve 121 is closed) or the flow pressure of the gas GAS on the second fluid tube 120 depending on the opening and closing of the second fluid valve 121. For example, the second pressure gauge 125 can measure the opening of the second fluid valve 121, and comprehensively, considering that the flow velocity of the gas GAS is limited, it can be understood that the second pressure gauge 125 measures the pressure of the positive pressure source PS or the pressure of the gas GAS supplied from the positive pressure source PS. The third pressure gauge 135 is connected on the third fluid pipe 130 between the negative pressure source NS and the third fluid valve 131, and can measure the pressure of the negative pressure source NS (for example, the closing of the third fluid valve 131) or the flow pressure of the gas GAS on the third fluid pipe 130 (for example, the opening of the third fluid valve 131) depending on the opening and closing of the third fluid valve 131, and comprehensively, considering that the flow velocity of the gas GAS is limited, it can be understood that the third pressure gauge 135 measures the pressure of the negative pressure source NS or the pressure of the gas GAS exhausted from the negative pressure source NS.

[0089] In one embodiment of the present invention, the internal pressure PI of the heating funnel 10 measured from the first pressure gauge 115, or the internal pressure PI of the heating funnel 10 relative to the external atmospheric pressure of 1 atm, can be used to confirm the pressure difference PIO between the inside and outside of the heating funnel 10. In order to satisfy the coating volume V per unit time of the first material M1 without excess or deficiency, which is set from the transfer path (width w of the scan line SL forming the transfer path) and transfer speed (distance L of the scan line SL per unit time corresponding to the transfer speed) of the first discharge nozzle 10a that discharges the flow of the first material M1, the heating funnel The volume per unit time of the gas GAS injected into the interior of the heating funnel 10 can be calculated, and the opening degrees of the first and second fluid valves 111 and 121 can be controlled by the pressure difference between the first and second pressure gauges 125 in the section where the pressure difference PIO between the inside and outside of the heating funnel 10 is controlled to be positive pressure, and the opening degrees of the first and third fluid valves 111 and 131 can be controlled by the pressure difference between the first and third pressure gauges 135 in the section where the pressure difference PIO between the inside and outside of the heating funnel 10 is controlled to be negative pressure.

[0090] In one embodiment of the present invention, the bidirectional pressure control unit 100 is Depending on the transfer path and transfer speed of the first discharge nozzle 10a, the pressure difference PIO between the inside and outside of the heating funnel 10 is set to a positive pressure in response to the deficiency of the coating volume V of the first material M1 per unit time, thereby accelerating the flow of the first material M1 from the heating funnel 10 toward the first discharge nozzle 10a, or, In accordance with the transfer path and transfer speed of the first discharge nozzle 10a, the pressure difference PIO between the inside and outside of the heating funnel 10 is set to a negative pressure in response to an excess of the coating volume V per unit time of the second material M2, thereby reducing or braking the flow of the first material M1 from the heating funnel 10 toward the first discharge nozzle 10a.

[0091] In one embodiment of the present invention, the bidirectional pressure control unit 100 is As the width w of the scan line SL increases along the width w of the scan line SL that forms the transfer path of the first discharge nozzle 10a, the pressure difference PIO inside and outside the heating funnel 10 is set to a positive pressure, thereby accelerating the flow of the first material M1 from the heating funnel 10 toward the first discharge nozzle 10a, or As the width w of the scan line SL decreases along the width w of the scan line SL that forms the transfer path of the first discharge nozzle 10a, the pressure difference PIO inside and outside the heating funnel 10 is set to a negative pressure, thereby slowing down or braking the flow of the first material M1 from the heating funnel 10 toward the first discharge nozzle 10a.

[0092] For example, the width w of the scan lines SL that form the transfer path of the first ejection nozzle 10a may be set so that they scan the entire build area where the object is formed, but do not overlap with each other and do not spread apart in order to block voids.

[0093] For example, the bidirectional pressure control unit 100 is Depending on the transfer speed of the first discharge nozzle 10a, or depending on the length L of the scan line SL per unit time corresponding to the transfer speed, the pressure difference PIO inside and outside the heating funnel 10 is set to a positive pressure in accordance with a relatively high transfer speed or a relatively long scan line SL length L per unit time, thereby accelerating the flow of the first material M1 from the heating funnel 10 toward the first discharge nozzle 10a, or Depending on the transfer speed of the first discharge nozzle 10a, or the length L of the scan line SL per unit time corresponding to the transfer speed, the pressure difference PIO inside and outside the heating funnel 10 is set to a negative pressure in accordance with a relatively low transfer speed or a relatively short scan line SL length L per unit time, thereby slowing down or braking the flow of the first material M1 from the heating funnel 10 toward the first discharge nozzle 10a.

[0094] For example, depending on the excess coating volume V per unit time of the first material M1, which is set according to the transfer path and transfer speed of the first discharge nozzle 10a, the pressure difference PIO inside and outside the heating funnel 10 is set to positive or negative pressure, thereby accelerating, decreasing, or braking the flow of the first material M1 from the heating funnel 10 toward the first discharge nozzle 10a. The coating volume V per unit time of the first material M1 can be calculated by multiplying the width w of the scan line SL that forms the transfer path, or the cross-sectional area of ​​the scan line SL including the width w dimension of the scan line SL, by the length L of the scan line SL per unit time, which corresponds to the scanning speed.

[0095] The following describes one aspect of a multiphase 3D printing apparatus according to one embodiment of the present invention.

[0096] In one embodiment of the present invention, a bidirectional pressure control unit 100 that provides positive and negative pressure in both directions, inverted to each other, can control the flow of the first material M1 that forms the molded object itself as it moves from the inside of the heating funnel 10 toward the external stage S (flow velocity and flow direction). By appropriately controlling the coating volume V per unit time with a first discharge nozzle 10a that is transported in real time to follow a transport plan including a preset transport path and transport velocity, the flow of the first material M1 discharged onto the stage S can be precisely controlled in real time so as not to result in an excess or deficiency of the preset coating volume V.

[0097] For example, in one embodiment of the present invention, if the flow of the first material M1 discharged from the first discharge nozzle 10a is insufficient to follow a preset transfer plan, a gap can be created in a portion of the coating volume V set on the transfer path. This can create empty spaces in the molded object that are not filled by the first material M1, i.e., voids in the molded object, on the transfer path. In contrast, in one embodiment of the present invention, if the flow of the first material M1 discharged from the first discharge nozzle 10a is discharged in an excess amount to follow a preset transport plan, an excess volume exceeding the set coating volume V can be formed on the transport path. This excess volume can form an additional height that exceeds the upper limit of the height defined by the filling space surrounded by the first material M1 forming the contour of the object. This can damage the height stability of the second material M2 by causing the dam of the second material M2, which acts as a dam to restrict the flow of the first material M1 while forming the contour of the object, or damage the precision of the shape of the object by forming an excess volume beyond the contour of the object, or cause the extra work of having to change the coating volume V of the layer following the layer because it exceeds the height of each layer forming the object.

[0098] In one embodiment of the present invention, the molding of the molded object is embodied by the transfer of a second discharge nozzle 20a that discharges a second material M2 that forms the contour of the molded object, and the transfer of a first discharge nozzle 10a that discharges a first material M1 that forms the interior of the molded object, i.e., the molded object itself, and for example, the transfer plan of the first and second discharge nozzles 10a and 20a for molding the molded object includes presetting the transfer path and transfer speed of the second discharge nozzle 20a that follows the outline profile that forms the contour of the molded object, the application volume V of the first material M1 per unit time set according to the transfer path and transfer speed of the first discharge nozzle 10a, the transfer path and transfer speed of the first discharge nozzle 10a that scans the interior region of the contour of the molded object to mold the molded object itself in the interior region of the contour of the molded object surrounded by the second material M2, and the application volume V of the first material M1 per unit time set according to the transfer path and transfer speed of the first discharge nozzle 10a.

[0099] In one embodiment of the present invention, the coating volume V per unit time of the first material M1 is set according to the transport path of the first discharge nozzle 10a that discharges the first material M1 or the width w of the scan line SL that forms the transport path. For example, even if it is the internal region of the contour of the same molded object, the coating volume V of the second material M2 set along each transport path or scan line SL width w will be different, depending on the preset transport path or scan line SL width w. For example, depending on the transport path or scan line SL width w, the number of scan lines SL required to form the same width of the molded object will change, and the coating volume V per unit time of the first material M1 will be set differently according to each transport path or scan line SL width w. For example, the widths w of the scan lines SL for forming the same width of the molded object may be set so as not to overlap with each other and not to form gaps or voids, and the coating volume V of the first material M1 along each scan line SL may be set according to the scan line SL width w.

[0100] As shown in Figure 15, the coating volume V of the first material M1 per unit time is set along the transport path or scan line width w of the first discharge nozzle 10a. For example, the coating volume V of the first material M1 per unit time is calculated by multiplying the length L of the scan line SL of the first discharge nozzle 10a per unit time, which corresponds to the transport speed of the first discharge nozzle 10a from which the first material M1 is discharged, by the width w of the scan line SL that forms the transport path. For example, in one embodiment of the present invention, due to the fluidity of the liquid phase first material M1, the width w of the scan line SL of the first discharge nozzle 10a is formed in a way that the first material M1 is formed in a shape that is not angular, such as a square cross-section. The coating volume V in one embodiment of the present invention can be assumed to be a round cross-section that is formed from the highest point while flowing outwards on both sides, for example, from the highest point formed at the central position along the width w direction of the scan line SL, that is, from the highest point formed at the central position along the width w direction of the scan line SL, due to the fluidity of the liquid phase first material M1, a round cross-section that spreads outwards on both sides along the width w direction of the scan line SL can be assumed to be a round cross-section in one embodiment of the present invention, and the volume in which the cross-section of the coating volume V thus assumed extends over the length L of the scan line SL per unit time of the first discharge nozzle 10a can be assumed to be a volume in which the first material M1 is coated per unit time.

[0101] Based on the above assumptions, the coating volume V (coating volume per unit time) of the first material M1 can be calculated as follows. [Mathematics 1] JPEG2026528665000002.jpg1373 Here, L represents the scanline distance SL per unit time.

[0102] In one embodiment of the present invention, the coating volume V of the first material M1 that forms the internal region of the molded object surrounded by the contour of the molded object or the molded object itself can be calculated from the width w of the scanline SL that forms the transport path of the first discharge nozzle 10a from which the first material M1 is discharged, and the length L of the scanline SL per unit time corresponding to the transport speed of the first discharge nozzle 10a. The coating volume V of the first material M1 discharged from the first discharge nozzle 10a can be calculated from the transport path and transport speed of the first discharge nozzle 10a that can be set from the transport plan of the first discharge nozzle 10a.

[0103] In one embodiment of the present invention, before activating the first and second ejection nozzles 10a and 20a for forming a molded object, a transfer plan for the first and second ejection nozzles 10a and 20a can be made, including a transfer path for the first and second ejection nozzles 10a and 20a, a transfer speed, and a preset application volume V of the first and second materials M1 and M2 set according to the transfer path and transfer speed. In this embodiment of the present invention, the amount of first material M1 ejected through the first ejection nozzle 10a is set to a preset amount of first material M1. The internal pressure PI of the heating funnel 10, more precisely, the pressure difference PIO between the inside and outside of the heating funnel 10, can be generated by controlling the inflow and outflow of gas GAS injected into or exhausted from the heating funnel 10, so as to fill the coating volume V without excess or deficiency. More specifically, the flow velocity of the flow of the first material M1 flowing from the inside of the heating funnel 10 toward the external stage S can be accelerated or decelerated by controlling the internal pressure PI of the heating funnel 10 in both positive and negative directions.

[0104] In one embodiment of the present invention, in the transport plan for the first and second ejection nozzles 10a and 20a set before the activation of the first and second ejection nozzles 10a and 20a, differences can be placed in the transport speeds of the first and second ejection nozzles 10a and 20a depending on the shape of the contour shape of the object or the shape of the scan line SL that scans the internal region of the object. For example, in a scan line SL that forms the contour of an object or the surface of an object that includes sharp corners, the first and second ejection nozzles 10a and 20a can be transported at a relatively delayed transport speed. Conversely, in a scan line SL that forms the contour of an object or the interior of an object that extends in a stripe pattern along one direction, In SL, the first and second discharge nozzles 10a and 20a can be transported at a relatively rapid transfer speed. The discharge speeds of the first and second materials M1 and M2 discharged through the first and second discharge nozzles 10a and 20a are controlled by these differentially set transfer speeds and in conjunction with the coating volumes V of the first and second materials M1 and M2, which are differentially set according to the differentially set transfer speeds. For example, to control the discharge speeds of the first and second materials M1 and M2, the internal pressure PI of the heated funnel 10 filled with the liquid phase first material M1 can be controlled, for example, to control the discharge speed of the first material M1 (acceleration and deceleration of the flow of the first material M1).For example, in a scanline SL where the transfer speed of the first discharge nozzle 10a from which the first material M1 is discharged is relatively delayed, in order to delay the discharge speed of the first material M1, the internal pressure PI of the heated funnel 10 filled with the liquid phase first material M1 is set to a relatively small scale positive pressure, or the control of the internal pressure PI of the heated funnel 10 is taken as input, and the output is the change in the flow velocity of the flow of the first material M1 from the inside of the heated funnel 10 toward the external stage S. Considering the point that the resolution of the control ability is relatively reduced in this input-output relationship of control, In a scanline SL with a relatively delayed transfer speed, the internal pressure PI of the heating funnel 10 can be controlled alternately between positive and negative pressure. For example, by applying a positive pressure to the internal pressure PI of the heating funnel 10 to accelerate the flow velocity of the first material M1, and then, once a set flow velocity or discharge volume of the first material M1 is reached, the internal pressure PI of the heating funnel 10 is reversed to negative pressure to decelerate the flow velocity of the first material M1, the first material M1 can be discharged at a flow velocity that converges between a certain upper and lower limit, or the flow velocity of the first material M1 can be controlled. As described above, in an embodiment in which the discharge or flow rate of the first material M1 is controlled by alternating reversals of positive and negative pressure, the reversal point between positive and negative pressure is captured, for example, by monitoring various state variables that can control the flow of the first material M1. In one embodiment of the present invention, the reversal point of pressure is determined by a combination of state variables that can be measured or monitored at various points, such as the internal pressure PI of the heating funnel 10 filled with the liquid phase first material M1, the flow rate of the flow of the first material M1 from the inside to the outside of the heating funnel 10, the discharge amount or discharge rate of the first material M1 discharged from the inside to the external stage S, and the accumulation rate of the first material M1 accumulated on the stage S.

[0105] In one embodiment of the present invention, the bidirectional pressure control unit 100 is Depending on the transfer path and transfer speed of the first discharge nozzle 10a, the pressure difference PIO between the inside and outside of the heating funnel 10 is set to a positive pressure in response to the deficiency of the coating volume V of the first material M1 per unit time, thereby accelerating the flow of the first material M1 from the heating funnel 10 toward the first discharge nozzle 10a, or, In accordance with the transfer path and transfer speed of the first discharge nozzle 10a, the pressure difference PIO between the inside and outside of the heating funnel 10 is set to a negative pressure in response to the excess coating volume V per unit time of the second material M2, thereby reducing or braking the flow of the first material M1 from the heating funnel 10 toward the first discharge nozzle 10a. More specifically, the bidirectional pressure control unit 100 is: As the width w of the scan line SL increases along the width w of the scan line SL that forms the transfer path of the first discharge nozzle 10a, the pressure difference PIO inside and outside the heating funnel 10 is set to a positive pressure, thereby accelerating the flow of the first material M1 from the heating funnel 10 toward the first discharge nozzle 10a, or As the width w of the scan line SL decreases along the width w of the scan line SL that forms the transfer path of the first discharge nozzle 10a, the pressure difference PIO inside and outside the heating funnel 10 is set to a negative pressure, thereby slowing down or braking the flow of the first material M1 from the heating funnel 10 toward the first discharge nozzle 10a.

[0106] For example, the bidirectional pressure control unit 100 is Depending on the transfer speed of the first discharge nozzle 10a, or depending on the length L of the scan line SL per unit time corresponding to the transfer speed, the pressure difference PIO inside and outside the heating funnel 10 is set to a positive pressure in accordance with a relatively high transfer speed or a relatively long scan line SL length L per unit time, thereby accelerating the flow of the first material M1 from the heating funnel 10 toward the first discharge nozzle 10a, or Depending on the transfer speed of the first discharge nozzle 10a, or the scan distance per unit time corresponding to the transfer speed, the pressure difference PIO between the inside and outside of the heating funnel 10 is set to a negative pressure, corresponding to a relatively low transfer speed or a relatively short scan line length L per unit time, thereby slowing down or braking the flow of the first material M1 from the heating funnel 10 toward the first discharge nozzle 10a.

[0107] In one embodiment of the present invention, the discharge amount or discharge rate of the first material M1 can be controlled by measuring and controlling the internal pressure PI of the heating funnel 10, which is satisfied by the first material M1, among the various state variables described above (first pressure gauge 115). For example, rather than measuring and controlling state variables that are difficult to measure, such as the discharge amount or discharge rate of the first material M1, the flow velocity of the first material M1 can be quickly and directly controlled by the internal pressure PI of the heating funnel 10, which is easily measured by the first pressure gauge 115 connected to the heating funnel 10, thereby increasing the speed of control in terms of the input-output relationship of the control.

[0108] In one embodiment of the present invention, regardless of whether the scanline SL is set to have a transfer speed that is relatively delayed in line with the transfer speed of the first discharge nozzle 10a, or whether the scanline SL is set to have a relatively rapid transfer speed, or whether the scanline SL is set to have a constant transfer speed, as well as a scanline SL with a variable transfer speed of the first discharge nozzle 10a, the bidirectional pressure control unit 100 connected to the heating funnel 10 can be controlled by alternating positive and negative pressure rather than controlling the bidirectional pressure control unit 100 connected to the heating funnel 10 by applying a constant positive pressure as described above.

[0109] In various embodiments of the present invention, the internal pressure PI of the heating funnel 10 can be alternately reversed between positive and negative pressure by the error between the internal pressure PI of the heating funnel 10, which is set to be linked to a preset transfer speed of the first discharge nozzle 10a, and the internal pressure PI of the heating funnel 10 measured in real time, or by the error between the discharge amount or discharge speed of the first material M1, which is set to be linked to a preset transfer speed of the first discharge nozzle 10a, and the discharge amount or discharge speed of the first material M1 measured in real time, thereby allowing the heating funnel 10 to follow a constant or variable transfer speed, or the discharge amount or discharge speed of the first material M1, which is linked to the transfer speed.

[0110] A multiphase 3D printing apparatus according to one embodiment of the present invention is A seal cover CV is used to cover and seal the opening at the upper end of the heating funnel 10, and is coupled opposite to the heating funnel 10. The heating funnel 10 and the sealing cover CV are connected by a sealing gasket GA for sealing the space between the heating funnel 10 and the sealing cover CV.

[0111] For example, the heating funnel 10 includes a seal flange 10f formed along the outer peripheral edge of the inlet at the upper end, The seal gasket GA is interposed between the seal flange 10f of the heating funnel 10 and the seal cover CV, which are joined facing each other by fastening means that penetrate the seal flange 10f of the heating funnel 10 and the plate-shaped seal cover CV, which are formed side by side.

[0112] For example, the heating funnel 10 and the seal cover CV are made of a metal material on which a surface coating layer is formed.

[0113] For example, the seal gasket GA includes matrix seeds stacked on top of each other and ceramic fibers interposed between the matrix seeds.

[0114] The following describes in more detail one aspect of a multiphase 3D printing apparatus according to one embodiment of the present invention.

[0115] In one embodiment of the present invention, the heating funnel 10 may be formed as a sealed space inside such that the internal pressure PI of the heating funnel 10 is controlled by a bidirectional pressure control unit 100 which is fluidly connected to the heating funnel 10. For example, in one embodiment of the present invention, the internal space of the heating funnel 10 is formed as a sealed space that is sealed from the external environment, such that the flow of the first material M1 filling the inside of the heating funnel 10 or the internal pressure PI of the heating funnel 10 is controlled by the provision of positive or negative pressure by a bidirectional pressure control unit 100 connected to the internal space, or by the discharge of the first material M1 from a first discharge nozzle 10a connected to the bottleneck position of the heating funnel 10. The internal space of the heating funnel 10 forming such a sealed space can have its internal pressure PI formed by the inflow and outflow of a substance filling the internal space, for example, by the injection or exhaust of a gas GAS which is controlled by the discharge of the first material M1 and the bidirectional pressure control unit 100, the internal pressure PI of the heating funnel 10 can be completely controlled and fluctuations in the internal pressure PI of the heating funnel 10 due to the external environment can be blocked. For example, in one embodiment of the present invention, the control of the internal pressure PI of a heating funnel 10 that is not sealed from the external environment may not be fully controlled by the bidirectional pressure control unit 100 due to pressure leakage between the internal pressure PI and the external environment.

[0116] In one embodiment of the present invention, the heating funnel 10, which is fluidly connected to the bidirectional pressure control unit 100, is formed in a sealed space that is isolated from the external environment, and pressure control from the external environment to the sealed space can be fully realized by the control of the bidirectional pressure control unit 100 by providing positive or negative pressure to the sealed space.

[0117] In one embodiment of the present invention, sealing of the internal space of the heating funnel 10 can be achieved by the heating funnel 10, a seal cover CV covering an inlet formed at the upper end of the heating funnel 10, and a seal gasket GA interposed between the inlet of the heating funnel 10 and the seal cover CV. In one embodiment of the present invention, the heating funnel 10 may include a seal flange 10f formed along the outer peripheral edge of the inlet at its upper end, and the seal flange 10f of the heating funnel 10 and the seal cover CV, which are formed in a flat plate shape, are joined facing each other via a fastening means that fastens the seal flange 10f of the heating funnel 10 and the seal cover CV, for example, the position of the edge of the heating funnel 10 on which the seal flange 10f is formed and the position of the edge of the seal cover CV are aligned and face each other in a flush shape, and the fastening member can be sandwiched so as to continuously penetrate the position of the edge of the heating funnel 10 on which the seal flange 10f is formed and the position of the edge of the seal cover CV which are arranged facing each other, thereby joining the heating funnel 10 and the seal cover CV. In one embodiment of the present invention, the heating funnel 10 and the seal cover CV are formed of the same heat-resistant material. For example, in one embodiment of the present invention, the heating funnel 10 and the seal cover CV are formed from a ceramic material or a heat-resistant metal material with excellent heat resistance. In various embodiments of the present invention, the heating funnel 10 and the seal cover CV are formed from a ceramic material or a metal material, and the ceramic material is suitably applicable to the heating funnel 10 and the seal cover CV of the present invention because it has excellent heat resistance and electrical insulating properties. However, in various embodiments of the present invention, the heating funnel 10 and the seal cover CV may be formed from a metal material that has excellent processability and relatively low surface illuminance, and thereby can provide lower flow resistance and lower pressure loss than a ceramic material, considering processability and pressure loss due to frictional flow of the first material M1 filling the inside of the heating funnel 10.In one embodiment of the present invention, unlike the flat seal cover CV, the funnel-shaped heating funnel 10 is formed by cutting a raw metal material. Due to the cutting marks of the cutting tool formed during the cutting of the raw metal material, the surface of the heating funnel 10 is formed with relatively high illumination. A surface coating layer may be formed on the surface of the heating funnel 10 to reduce the surface illumination and prevent damage such as corrosion of the heating funnel 10 in the high-temperature operating environment. In various embodiments of the present invention, similar to the heating funnel 10, the seal cover CV for sealing the inlet at the upper end of the heating funnel 10 is also formed from a metal material similar to the heating funnel 10, and for example, a surface coating layer may be formed similarly to the heating funnel 10.

[0118] In one embodiment of the present invention, the heating funnel 10 and the seal cover CV are arranged such that the positions of the edges of the heating funnel 10 on which the seal flange 10f is formed and the positions of the edges of the seal cover CV face each other side by side. They are joined facing each other via a fastening member that penetrates the positions of the edges of the heating funnel 10 on which the seal flange 10f is formed and the positions of the edges of the seal cover CV, which face each other side by side. A seal gasket GA is interposed between the heating funnel 10 and the seal cover CV, which are joined facing each other, to seal them without any gaps. For example, in one embodiment of the present invention, the seal gasket GA is made of a material that has excellent sealing properties as well as high temperature resistance. For example, the seal gasket GA may be made of a material that has cushioning or sealing properties that can adaptively deform to the shape between the heating funnel 10 and the seal cover CV while maintaining shape stability in the high temperature and high pressure environment between them. For example, in one embodiment of the present invention, the seal gasket GA is formed in the form of a composite material including a number of matrix seeds stacked on top of each other and ceramic fibers interposed between the matrix seeds. For example, in one embodiment of the present invention, the seal gasket GA may be formed of a flexible graphite and carbon gasket GA.

[0119] In 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 discharged from the inside of the heating funnel 10 toward the external stage S. Below, 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.

[0120] (1) The end position FP of the scan line SL along the scan line SL that forms the transfer path of the first discharge nozzle 10a (see Figure 17) In one embodiment of the present invention, at the end position FP (see Figure 17) of the scan line SL, which forms the transfer path of the first discharge nozzle 10a from which the first material M1 is discharged, the pressure difference between the inside and outside of the heating funnel 10 containing the first material M1 is set to a negative pressure, thereby quickly braking the flow of the first material M1. For example, prior to the end position FP (see Figure 17) of the scan line SL, along the scan line SL where the discharge of the first material M1 or the flow of the first material M1 toward the external stage S continues, in order to quickly interrupt the inertia of the first material M1 that tends to continue flowing toward the external stage S, in one embodiment of the present invention, the pressure difference between the inside and outside of the heating funnel 10 containing the first material M1 is set to a negative pressure. For example, at the end position FP (see Figure 17) of the scanline SL or a position adjacent to the end position FP (see Figure 17), the previous positive pressure is shut off (second fluid valve 121 is turned off) and negative pressure is started (third fluid valve 131 is turned on), so at the end position FP (see Figure 17) of the scanline SL, the inertia of the first material M1 which tends to be ejected from the heating funnel 10 toward the external stage S is shut off, and the flow of the first material M1 can be immediately slowed down or braked. For example, the first material M1 is ejected to a position outside the predetermined transfer path of the first ejection nozzle 10a or the end position FP (see Figure 17) of the scanline SL of the first ejection nozzle 10a, so that the shape of the molded object formed from the first material M1 does not deviate from the desired shape and become distorted.

[0121] For example, in one embodiment of the present invention, a specific object of a desired shape can be formed by stacking each layer of the object using sliced ​​section data of the object to be fabricated as input. For example, each layer forming the object may include a start position SP (see Figure 17) and an end position FP (see Figure 17) along the transport path of the first ejection nozzle 10a from which the first material M1 forming the object itself is ejected, or along the scan line SL that forms the transport path of the first ejection nozzle 10a. At this time, at the end position FP of the scanline SL (see Figure 17), the inertia of the flow of the first material M1 continuing along the scanline SL is quickly interrupted, preventing the flow or discharge of the first material M1 from continuing from inside the heating funnel 10 toward the external stage S even after leaving the preset end position FP of the scanline SL (see Figure 17). The inertia of the flow of the first material M1, that is, the inertia of the flow of the first material M1 attempting to move from inside the heating funnel 10 toward the external stage S, is quickly interrupted, and the flow of the first material M1 is braked. To set the pressure difference between the inside and outside of the heating funnel 10 to a negative pressure, the third fluid valve 131, which disconnects the connection of the third fluid pipe 130 connected to the negative pressure source NS, is turned on, and the second fluid valve 121, which disconnects the connection of the second fluid pipe 120 connected to the positive pressure source PS, is turned off.

[0122] In one embodiment of the present invention, the inertia that attempts to continue the discharge of the first material M1 along the scanline SL or the flow of the first material M1 toward the external stage S includes the inertia that attempts to continue the previous motion of the flow of the first material M1 from the inside of the heating funnel 10 toward the external stage S along the scanline SL, unless there are separate pressure fluctuations or fluctuations in flow resistance. This can be used in a comprehensive sense to include, for example, the control of a valve controller 150 that controls the first to third fluid valves 131 to change the pressure difference inside and outside the heating funnel 10 in order to decelerate the flow of the first material M1, and the control delay from the start of such control of the valve controller 150 until the pressure difference inside and outside the heating funnel 10 actually changes in response to the control of the valve controller 150. For example, in a comparative example that differs from the present invention and does not include a bidirectional pressure control unit 100 that can set the pressure difference between the inside and outside of the heating funnel 10 to be positive or negative in both directions, it is possible to decelerate the flow of the first material M1 discharged from the first discharge nozzle 10a by gradually decreasing the level of positive pressure at the end position FP of the first discharge nozzle 10a (see Figure 17). However, in such a comparative example, it is difficult to rapidly decelerate or provide the flow of the first material M1 moving from the inside of the heating funnel 10 toward the external stage S. For example, as the level of positive pressure at which the inertia of the flow of the first material M1 that attempts to maintain or continue the flow of the first material M1 gradually decreases weakens in line with the relative increase in flow resistance, a certain amount of time may be required for the flow of the first material M1 to be substantially decelerated or braked.

[0123] In one embodiment of the present invention, the end position FP (see Figure 17) of the scanline SL that forms the shape of the molded object is set to a negative pressure at the end position FP (see Figure 17) of the scanline SL so as not to form a tail of the scanline SL inside and outside the shape of the molded object while forming a sharp step, so as to immediately interrupt the inertia of the flow of the first material M1 and immediately brake the flow of the first material M1. For example, the turn-off and turn-on switching operation of the second and third fluid valves 121 and 131 for intermittently connecting the second and third fluid pipes 120 and 130 connected to the respective positive pressure source PS and negative pressure source NS can be realized.

[0124] (2) Coating interruption section ST between the end position FP (see Figure 17) and the start position SP (see Figure 17) of the scan line SL that forms the transfer path of the first discharge nozzle 10a. In one embodiment of the present invention, an object can be formed by inputting sliced ​​section data of the object to be fabricated and stacking each layer of the object, or by accumulating the number of turns that form the object. In such a method of forming an object by stacking multiple layers or accumulating a large number of turns, 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 decelerate or brake the flow of the first material M1 that forms the object itself, between the transfer path of the preceding layer (or preceding turn, hereinafter the same) or the end position FP (see Figure 17) of the scan line SL forming the transfer path, and the transfer path of the subsequent layer (or subsequent turn, hereinafter the same) stacked on the preceding layer (or preceding turn, hereinafter the same) or the start position SP (see Figure 17) of the scan line SL forming the transfer path. For example, in one embodiment of the present invention, each layer of the object can be formed by accumulating the preceding and succeeding turns, and the object can be formed by stacking the preceding and succeeding layers.

[0125] In one embodiment of the present invention, a coating interruption section ST is formed between a preceding layer (or preceding turn) and a succeeding layer (or succeeding turn) that are stacked on top of each other to form the desired shape of the molded object, during which the coating of the first material M1 is stopped. To sharply follow this coating interruption section ST, 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 in the coating interruption section ST between the end position FP of the preceding layer (see Figure 17) and the start position SP of the succeeding layer (see Figure 17) to block unintended ejection of the first material M1. For example, as described above, the negative pressure applied at the end position FP (see Figure 17) of the scan line SL that forms the transfer path of the first discharge nozzle 10a from which the first material M1 is discharged, i.e., the negative pressure applied at the end position FP (see Figure 17) of the scan line SL in the preceding layer, continues to the start position SP (see Figure 17) of the scan line SL in the following succeeding layer, thereby preventing unintended leakage of the first material M1 during the coating interruption section ST set between the preceding and succeeding layers. Thus, in one embodiment of the present invention, the flow of the first material M1 in the coating interruption section ST can be blocked by setting the pressure inside and outside the heating funnel 10, without relying on a separate valve structure to interrupt the fluid connection of the first discharge nozzle 10a connected to the bottleneck portion of the heating funnel 10. However, in various embodiments of the present invention, even if negative pressure is not applied separately at the start position SP (see Figure 17) of the scan line SL of the preceding layer, until the second fluid valve 121, which disconnects the connection of the second fluid pipe 120 connected to the positive pressure source PS, is turned on, the flow of the first material M1 may remain stopped due to the inertia of the first material M1, which attempts to maintain the state in which the flow of the first material M1 is stopped.For example, in various embodiments of the present invention, as the first discharge nozzle 10a for discharging the first material M1 moves from the end position FP of the preceding layer (see Figure 17) to the start position SP of the succeeding layer (see Figure 17), a switching operation may be implemented at the start position SP of the succeeding layer (see Figure 17) in which a second fluid valve 121 for disconnecting and disconnecting the connection of a second fluid pipe 120 connected to a positive pressure source PS is turned on, and a third fluid valve 131 for disconnecting and disconnecting the connection of a third fluid pipe 130 connected to a negative pressure source NS is turned off.

[0126] (3) Drive sections T1 and T2 of the second discharge nozzle 20a for forming the outline of the molded object (see Figure 19) In one embodiment of the present invention, after the contour of the molded object is formed by driving the second discharge nozzle 20a to form the contour of the molded object, the first material M1 can be filled into the internal molding region surrounded by the contour of the molded object formed by the second material M2 discharged from the second discharge nozzle 20a, while driving the first discharge nozzle 10a, under the height restriction of the second material M2 surrounding the molding region (see Figure 14). Thus, in one embodiment of the present invention, the second discharge nozzle 20a from which the second material M2 is discharged to form the contour of the molded object and the first discharge nozzle 10a from which the first material M1 is discharged to form the molded object itself are embedded in an embedded block 40 that restrains both the first and second discharge nozzles 10a and 20a, and are positioned in a fixed position adjacent to each other by the restraint of such embedded block 40, and the first and second discharge nozzles 10a and 20a can alternately drive each other to alternately form the contours that form each layer of the molded object and the cross-sectional structure of the molded object, respectively. The drive of a multiphase three-dimensional printing apparatus according to one embodiment of the present invention may include a drive section T1 (see Figure 19) of the first discharge nozzle 10a, in which the embedded block 40 that restrains both the first and second discharge nozzles 10a and 20a moves along the transport path of the first discharge nozzle 10a or along the scan line SL of the first discharge nozzle 10a, or a drive section T2 (see Figure 19) of the second discharge nozzle 20a, in which the embedded block 40 that binds both the first and second discharge nozzles 10a and 20a moves along the transport path of the second discharge nozzle 20a or along the scan line SL of the second discharge nozzle 20a, and these drive sections T1 and T2 (see Figure 19) of the first and second discharge nozzles 10a and 20a may be operated in mutually exclusive time slots.

[0127] In one embodiment of the present invention, the driving of the first discharge nozzle 10a is stopped during the driving section T2 of the second discharge nozzle 20a (see Figure 19), and the pressure difference between the inside and outside of the heating funnel 10 containing the first material M1 may be set to a negative pressure during the driving section T2 of the second discharge nozzle 20a (see Figure 19) to block unintended leakage of the first material M1 from the first discharge nozzle 10a. However, in one embodiment of the present invention, at the end position FP (see Figure 17) of the drive section T1 (see Figure 19) of the first discharge nozzle 10a, or at the end position FP (see Figure 17) of the transfer path of the first discharge nozzle 10a, or at the end position FP (see Figure 17) of the scan line SL of the first discharge nozzle 10a that forms the transfer path of the first discharge nozzle 10a, the flow of the first material M1 is braked by a negative pressure set as the pressure difference between the inside and outside of the heating funnel 10. Due to the inertia of the first material M1 that tries to maintain the state in which the flow of the material is braked, no additional negative pressure setting may be realized after the end position FP (see Figure 17) of the drive section T1 (see Figure 19) of the first discharge nozzle 10a, or after the end position FP (see Figure 17) of the transfer path of the first discharge nozzle 10a or the scan line SL of the first discharge nozzle 10a. In this case as well, the flow of the first material M1 from the heating funnel 10 containing the first material M1 toward the external stage S can be kept stopped.

[0128] (4) Control of the flow of the first fluid along the transfer path of the first discharge nozzle 10a In one embodiment of the present invention, in order to increase the response rate from controlling the flow of the first material M1 along the transfer path of the first discharge nozzle 10a, the control of the flow of the first material M1 along the transfer path of the first discharge nozzle 10a is embodied by i) on / off control of a second fluid valve 121 that intermittently connects a second fluid pipe 120 connected to a positive pressure source PS, and on / off control of a third fluid valve 131 that intermittently connects a third fluid pipe 130 connected to a negative pressure source NS (see Figures 16B and 16C), and the second and third The valve control signals output from the valve controller 150 by the on / off control of the fluid valves 121 and 131 are simplified to on and off control signals output to the respective second and third fluid valves 121 and 131. For example, it is not necessary to have multiple levels of control signals set to control the opening degree of the second and third fluid valves 121 and 131. This simplifies the structure of the second and third fluid valves 121 and 131 and the structure of the valve controller 150 for controlling these second and third fluid valves 121 and 131. Thus, in order to set the pressure difference between the inside and outside of the heating funnel 10 to multiple pressure levels from the on / off control of the respective second and third fluid valves 121 and 131, the on / off control of the respective second and third fluid valves 121 and 131 can be controlled alternately to follow the target pressure (see Figures 16B and 16C).

[0129] In one embodiment of the present invention, the control of the flow of the first fluid along the transfer path of the first discharge nozzle 10a is embodied by ii) on / off control and the degree of opening of a second fluid valve 121 that intermittently connects a second fluid pipe 120 connected to a positive pressure source PS, and on / off control of a third fluid valve 131 that intermittently connects a third fluid pipe 130 connected to a negative pressure source NS (see Figures 18B and 18C). Thus, the flow of the first material M1 is controlled by controlling the second fluid valve 121 which can control both the opening and closing and the degree of opening of the second fluid pipe 120 connected to each 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, the first discharge nozzle 1 from which the first material M1 is discharged. When it is necessary to slow down the flow of the first material M1 along the transfer path 0a or along the scanline SL forming the transfer path, for example, by reducing the transfer speed of the first discharge nozzle 10a or by reducing the width w of the scanline SL, the valve controller 150 can reduce the opening of the second fluid valve 121 that intermittently connects the second fluid pipe 120 connected to the positive pressure source PS, and at the same time instantaneously open and close the third fluid valve 131 that intermittently connects the third fluid pipe 130 connected to the negative pressure source NS with a short pulse waveform, for example, the control signal output from the valve controller 150 toward the second fluid valve 121 for a predetermined rising time (rising) to reduce the opening of the second fluid valve 121. The control signal, which is output as a sloping ramp-shaped waveform having a predetermined falling time (time) or a predetermined falling time, can be output as a pulse-shaped waveform with no rising time and falling time, or with short rising and falling times, as the third fluid valve 131 is opened and closed at short time intervals (see Figures 18B and 18C).For example, in one embodiment of the present invention, the valve controller 150 can output a control signal of a sloped ramp waveform having a first rise time or a first fall time for controlling the opening degree of the second fluid valve 121, and can output a control signal of a pulse waveform having a second rise period or a second fall time that is shorter than the first rise time or first fall time for sequential on / off control of the third fluid valve 131 (see Figures 18B and 18C).

[0130] For example, in one embodiment of the present invention, a second fluid valve 121 connected to a positive pressure source PS can form a continuously changing control signal for controlling its opening, for example, a ramp-shaped waveform having a predetermined rise time, thereby the opening of the second fluid valve 121 includes the predetermined rise time and a further time delay in addition to the rise time, and consequently, in controlling the opening of the second fluid valve 121, a certain delay time is unavoidable for the transition from the first opening to the second opening (continuous change from the first opening to the second opening), for example, the transfer speed changes discontinuously along the transfer path of the first discharge nozzle 10a from which the first material M1 is discharged (for example, a change in transfer speed between a curved section and a straight section), or In a driving environment where discontinuous changes in the coating volume of the first material M1 are preferred, the control of the second fluid valve 121 on the positive pressure source PS side and the third fluid valve 131 on the negative pressure source NS side can be simultaneously realized, including the control of the opening degree of the second fluid valve 121 connected to the positive pressure source PS side, and the instantaneous opening-closing control of the third fluid valve 131 connected to the negative pressure source NS side, thereby inducing discontinuous changes in the flow of the first material M1 that follow the discontinuous changes in the coating volume of the first material M1.

[0131] As described above, in one embodiment of the present invention, there are two distinct control methods (see Figures 18B and 18C): i) a control method in which the flow of the first material M1 is controlled by on / off control of the second fluid valve 121 on the positive pressure source PS side and on / off control of the third fluid valve 131 on the negative pressure source NS side (see Figures 16B and 16C), and ii) a control method in which the flow of the first material M1 is controlled by on / off control and opening degree control of the second fluid valve 121 on the positive pressure source PS side and on / off control of the third fluid valve 131 on the negative pressure source NS side, in which the on / By switching it off, the flow of the first material M1 can be controlled in conjunction with the on / off control of the second fluid valve 121 on the positive pressure source PS side, or the flow of the first material M1 can be controlled by the on / off control and opening degree control of the second fluid valve 121 on the positive pressure source PS side. In driving environments where discontinuous changes in the coating volume of the first material M1 (coating volume per unit time) are preferred, the transient response characteristics can be improved by simultaneously inducing deceleration or braking of the flow of the first material M1, while instantaneously or stepwise tracking the decreased change in the coating volume of the first material M1 that corresponds to the tracking target.

[0132] Thus, in one embodiment of the present invention, the second fluid valve 121 on the positive pressure source PS side is controlled in an on / off manner, or its opening degree is controlled along with the on / off state. Unlike these different control methods for the second fluid valve 121 on the positive pressure source PS side, the third fluid valve 131 on the negative pressure source NS side can be controlled in an on / off manner to induce deceleration and braking of the fluid flow of the first material M1, in particular to induce discontinuous changes in the fluid flow of the first material M1. This avoids the computational resources and burden required to implement not only on / off control but also opening degree control of the third fluid valve 131 on the negative pressure source NS side.

[0133] (Transfer of the first and second discharge nozzles 10a and 20a, and stage S) Throughout this specification, the transfer of the first and second discharge nozzles 10a and 20a may include the absolute transfer of the first and second discharge nozzles 10a and 20a, and may encompass the relative transfer of the stage S with respect to the first and second discharge nozzles 10a and 20a. For example, in one embodiment of the present invention, the movement of the stage S on which the first and second materials M1 and M2 discharged from the first and second discharge nozzles 10a and 20a are accumulated can form a trajectory or trace of the first and second materials M1 and M2 that substantially follows a transfer path planned on the stage S, similar to the transfer of the first and second discharge nozzles 10a and 20a, and the relative transfer between the first and second discharge nozzles 10a and 20a and the stage S by the transfer of the first and second discharge nozzles 10a and 20a or the transfer of the stage S can form a trajectory or trace of the first and second materials M1 and M2 accumulated on the stage S that forms the contour of the printed object and the object surrounded by the contour. For example, in one embodiment of the present invention, the relative transfer between the first and second discharge nozzles 10a and 20a and the stage S is performed from the stage S, which has a relatively shorter power transmission distance to the actuator A, and throughout this specification, the movement of the stage S relative to the fixed position first and second discharge nozzles 10a and 20a may be represented by the transfer of the first and second discharge nozzles 10a and 20a.

[0134] A multiphase 3D printing apparatus according to one embodiment of the present invention is The device includes a first discharge nozzle 10a for discharging a liquid-phase first material M1 to form an object on a stage S, a heating funnel 10 connected to the first discharge nozzle 10a and filled with the liquid-phase first material M1, and a bidirectional pressure control unit 100 connected to the heating funnel 10 for setting the pressure difference PIO between the inside and outside of the heating funnel 10 to positive or negative pressure. Furthermore, it further includes a second discharge nozzle 20a for discharging a paste-like or slurry-like second material M2 that forms the contour of the molded object, The width w of the scan line SL that forms the transfer path of the first discharge nozzle 10a is set to scan the entire build area where the build object is formed, which corresponds to the filling space surrounded by the contour of the build object formed from the second material M2.

[0135] For example, a multiphase three-dimensional printing apparatus according to one embodiment of the present invention further includes an extruder 80 connected to the second discharge nozzle 20a, which extrudes the second material M2 toward the second discharge nozzle 20a so as to discharge the second material M2, which is in the form of a paste or slurry, in which ceramic particles and a matrix in which ceramic particles are dispersed.

[0136] For example, a multiphase 3D printing apparatus according to one embodiment of the present invention is The heating chamber 50 further includes a heating chamber 50 for providing a slow-cooling space 50' for the first and second materials M1 and M2 accumulated on the stage S from the first and second discharge nozzles 10a and 20a, while housing the stage S. The pressure difference PIO between the inside and outside of the heating funnel 10 corresponds to the internal pressure PI of the heating funnel 10 containing the liquid-phase first material M1, with reference to the atmospheric pressure of the slow-cooling space 50' of the heating chamber 50.

[0137] The following describes in more detail one aspect of a multiphase 3D printing apparatus according to one embodiment of the present invention.

[0138] A multiphase 3D printing apparatus according to one embodiment of the present invention is A stage S provides a support base for the object to be fabricated, A first and second discharge nozzle 10a and 20a are arranged on a stage S to discharge a paste-like or slurry-like second material M2 that forms the outline of the molded object, and a liquid-phase first material M1 that fills the filling space surrounded by the outline of the molded object formed by the second material M2, respectively. An extrusion device 80 connected to the second discharge nozzle 20a for extruding the second material M2 toward the second discharge nozzle 20a so as to discharge the second material M2, which is in the form of a paste or slurry and is a mixture of ceramic particles and a matrix in which ceramic particles are dispersed. A heating funnel 10 connected to the first discharge nozzle 10a is used to melt a metal block, and the metal block is fed into the heating funnel 10 so as to discharge the first material M1 of the molten liquid phase of the metal block through the first discharge nozzle 10a. The system includes a heating chamber 50 for providing a slow-cooling space 50' for the first and second materials M1 and M2 accumulated on the stage S from the first and second discharge nozzles 10a and 20a, while accommodating the stage S.

[0139] The first material M1 is formed from a liquid phase metal or metal flow that is formed from a heating funnel 10 into which a solid phase metal block is input and heated to a point above its melting point. The molten metal or metal flow in the internal space of the heating funnel 10 can be discharged onto the stage S via a first discharge nozzle 10a that forms the lower end of the heating funnel 10.

[0140] Regarding the second material M2, the second material M2 is formed from a paste-like or slurry-like composite material which is a mixture of solid-phase ceramic particles and liquid-phase (or gel-phase) vehicles and / or binders, for example, the ceramic particles have a particle size on the μm scale. While such a second material M2 is formed as a paste-like or slurry-like material in which ceramic particles are dispersed, it has lower fluidity than the first material M1 which is formed from liquid-phase metal or metal flow. The second material M2 can be forcibly transported by extrusion via a second discharge nozzle 20a or a connecting pipe 70 connected to the second discharge nozzle 20a so as to form a homogeneous mixture (or dispersion at a homogeneous concentration) between the ceramic particles (solid phase) having different material phases and the matrix (liquid phase or gel phase) containing the ceramic particles.

[0141] For example, the extruder 80 for extruding the first material M1 may include a first hopper 81 into which ceramic particles forming the solid phase component of the first material M1 are introduced, and a second hopper 82 into which a matrix containing the ceramic particles to form a paste or slurry is introduced. The ceramic particles and matrix introduced from the first and second hoppers 81 and 82 are introduced together into the transfer pipe 83 of the extruder 80 and are transferred along the supply direction toward the stage S while being mixed together by a rotating screw 85 formed inside the transfer pipe 83. For example, the material M1 can be discharged onto the stage S via a connecting pipe 70 that mediates the transfer of the first material M1 between the discharge port 80a of the extruder 80 and a first discharge nozzle 10a formed on the stage S, or a discharge unit 20 including a first discharge nozzle 10a at the lower end of the discharge unit 20, along the discharge unit 20 embedded in a recessed block 40 (described later), via the first discharge nozzle 10a at the lower end of the discharge unit 20. For example, in one embodiment of the present invention, the upstream end of the connecting pipe 70 may be connected to the discharge port 80a of the extruder 80, and the downstream end of the connecting pipe 70 may be connected to a discharge unit 20 including the first discharge nozzle 10a at the lower end.

[0142] The heating funnel 10 and the discharge unit 20 are both embedded within an embedding block 40, and the embedding block 40 can define the distance between the first discharge nozzle 10a forming the lower end of the heating funnel 10 and the second discharge nozzle 20a forming the lower end of the discharge unit 20 by embedding and fixing the heating funnel 10 and the discharge unit 20 together within the embedding block 40. In one embodiment of the present invention, the embedding block 40 surrounds the first heat source 15 wound on the outer circumferential surface of the heating funnel 10, and can insulate the internal space of the heating funnel 10 from the surrounding environment so as to maintain the temperature of the internal space of the heating funnel 10, controlled by the first heat source 15, at a temperature above the melting point of the metal block, and can maintain the temperature of the discharge unit 20, located on the opposite side of the heating funnel 10 via 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. In one embodiment of the present invention, the embedding block 40 is made of an insulating material.

[0143] In one embodiment of the present invention, the embedded block 40 embeds most of the heating funnel 10 and the dispensing unit 20, but can expose the inlet forming the upper end of the heating funnel 10 and the fitting end 20b forming the upper end of the dispensing unit 20, and the upper parts of the heating funnel 10 and the dispensing unit 20 can be exposed with a predetermined clearance, including the upper end of the heating funnel 10 for loading metal blocks and the upper end of the dispensing unit 20 for connecting the connecting pipe 70, respectively. In one embodiment of the present invention, 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 dispensing unit 20, the upper part of the embedded block 40 exposes the electrical contacts 15a of the first heat source 15 surrounding the outer circumferential surface of the heating funnel 10, and the electrical contacts 15a of the first heat source 15 protrude to the highest level so as to block electrical interference with other surrounding components, for example, protruding to a higher level than the inlet of the heating funnel 10 and the fitting end 20b of the dispensing unit 20 along the height direction Z1.

[0144] The embedded block 40 may include an upper block 41 formed relatively high to embed most of the heating funnel 10 and the discharge unit 20, and a lower block 42 formed in an area extended from the upper block 41, thereby forming a slow-cooling space 50' which includes an upper part closed by the lower block 42, a side closed by the partition wall 50a of the heating chamber 50, and a lower part closed by the bottom wall 50b of the heating chamber 50. For example, in one embodiment of the present invention, the slow-cooling space 50' is formed from the assembly of the embedded block 40 and the heating chamber 50, and a second heat source 55 is formed on the partition wall 50a of the heating chamber 50 that forms the slow-cooling space 50'. The heating chamber 50 provides a slow-cooling space 50' for the first and second materials M1 and M2 accumulated on the stage S from the first and second discharge nozzles 10a and 20a while housing the stage S. For example, in one embodiment of the present invention, the pressure difference between the inside and outside of the heating funnel 10 corresponds to the internal pressure of the heating funnel 10 containing the first material M1, with reference to the pressure in the slow-cooling space 50' of the heating chamber 50 (e.g., atmospheric pressure of 1 atm).

[0145] An opening 50'' is formed in the bottom wall 50b of the heating chamber 50 to allow power connection between the stage S and the actuator A (first to third actuators). The stage S and the actuator A can be power-connected to each other by passing a connecting rod 100 through the opening 50'' which power-connects the stage S and the actuator A that provides driving power to the stage S. In one embodiment of the present invention, the embedded block 40, the heating chamber 50 and the actuator A can be aligned relative to each other by an assembly guide rod R.

[0146] Throughout this specification, setting the pressure difference between the inside and outside of the heating funnel 10 to a negative pressure means that the application of negative pressure to block the pressure difference between the inside and outside of the heating funnel 10 occurs over a relatively short period of time (duration). Therefore, negative pressure can be provided in a step or pulse-like manner over 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 stage S. For example, setting the pressure difference between the inside and outside of the heating funnel 10 to a negative pressure does not mean that the negative pressure is maintained without being eliminated, or that the negative pressure is maintained for a considerable period of time.

[0147] In one embodiment of the present invention, a path plan for the first discharge nozzle 10a can be generated before the first discharge nozzle 10a is driven, that is, before the first material M1 is discharged from the first discharge nozzle 10a. For example, the path plan for the first discharge nozzle 10a can be configured to set the transport path of the first discharge nozzle 10a and any configuration related to the discharge of the first material M1, such as the transport speed and discharge speed, at each position along the transport path. However, in various embodiments of the present invention, the discharge of the first material M1 from the first discharge nozzle 10a does not necessarily involve the transfer of the first discharge nozzle 10a, i.e., relative transfer between the first discharge nozzle 10a and the stage S. Due to the fluidity of the first material M1, the first material M1 discharged from the first discharge nozzle 10a can fill the internal filling space of the contour of the molded object formed with the second material M2 based on its relatively high fluidity, even when the first discharge nozzle 10a is in a stopped state, i.e., when the relative position of the first discharge nozzle 10a and the stage S is fixed. In such embodiments as well, the discharge of the first material M1 can be stopped by setting the pressure difference between the inside and outside of the heating funnel 10 to a negative pressure, thereby blocking the inertia of the flow of the first material M1 from the heating funnel 10 toward the stage S.

[0148] In one embodiment of the present invention, before the first material M1 is ejected, the transfer path and transfer speed of the first ejection nozzle 10a are set from the path plan of the first ejection nozzle 10a from which the first material M1 is ejected. At this time, the transfer path of the first ejection nozzle 10a is set to fill the filling space inside the contour of the molded object formed with the second material M2. For example, in one embodiment of the present invention, the transfer path of the first ejection nozzle 10a may be set so that the scan lines SL forming the transfer path do not overlap each other, or so that the scan lines SL forming the transfer path partially overlap each other. In various embodiments of the present invention, the transfer path of the first ejection nozzle 10a is formed by scan lines SL that overlap each other while filling the contour of the molded object formed with the second material M2, or by scan lines SL that do not overlap each other.

[0149] In one embodiment of the present invention, first and second discharge nozzles 10a and 10b for discharging first and second materials M1 and M2, respectively, can be integrally transported by a binding structure that structurally binds these first and second discharge nozzles 10a and 10b together (for example, embedded inside a embedding block 40 and structurally bound together). For example, the first and second discharge nozzles 10a and 10b discharge the first material M1 from the first discharge nozzle 10a while being transported along the transport path of the first discharge nozzle 10a, or discharge the second material M2 from the second discharge nozzle 10b while being transported along the transport path of the second discharge nozzle 10b. However, in various embodiments of the present invention, the first and second discharge nozzles 10a and 10b can simultaneously discharge the first and second materials M1 and M2, respectively, while being transported with a certain gap between them, and the first material M1 can be accumulated in its internal position along the contour of the molded object formed from the second material M2, thereby forming the molded object. For example, the contour of the molded object and the molded object itself may be formed simultaneously by the integrated transport of the first and second discharge nozzles 10a and 10b. For example, the first and second discharge nozzles 10a and 10b for discharging the first and second materials M1 and M2 can be configured to discharge the first material M1 following the transfer path of the first discharge nozzle 10a and the second material M2 following the transfer path of the second discharge nozzle 10b in different time slots in a time series, while setting the pressure difference between the inside and outside of the heating funnel 10 containing the first material M1 to a negative pressure so as to block leakage of the first material M1 when the second material M2 is discharged. The setting of the negative pressure to block leakage of the first material M1 when the second material M2 is discharged can be done in a variety of necessary or driving environments.

[0150] In 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 stage S, the on / off control of a second fluid valve 121 connected to a positive pressure source PS and the on / off control of a third fluid valve 131 connected to a negative pressure source NS are alternately controlled, for example, the inertia of the flow of fluid inside the second fluid pipe 120 to which each second fluid valve 121 is connected and the third fluid pipe 130 to which each third fluid valve 131 is connected, and the turn on / off of the second and third fluid valves 121 and 131. Considering the time delay (a kind of latency) between the input, which is the on / off state, and the output, which is the pressure difference between the inside and outside of the heating funnel 10, the on / off states of the second and third fluid valves 121 and 131 may be controlled in a manner that partially overlaps with each other along the time axis. For example, considering the inertia or time delay of the fluid flow, the on / off states of the second and third fluid valves 121 and 131 may be controlled in a manner that partially overlaps with each other along the time axis as one of the controls is initiated in a previous time step. In various embodiments of the present invention, the on / off states of the second and third fluid valves 121 and 131 may be performed in an exclusive manner that does not overlap with each other along the time axis.

[0151] In one embodiment of the present invention, the bidirectional pressure control unit 100 (more specifically, the valve controller 150) controls the on / off state and opening degree of a second fluid valve 121 connected to a positive pressure source PS, and controls the on / off state and opening degree of a third fluid valve 131 connected to a negative pressure source NS. In other words, in one embodiment of the present invention, the valve controller 150 can control the opening degree of the third fluid valve 131, which is connected to a negative pressure source NS, along with the on / off state of the third fluid valve 131. For example, in order to set a negative pressure in advance on the time axis, the length of the ON interval of the third fluid valve 131 connected to the negative pressure source NS can be used to control the opening degree of the third fluid valve 131 in the current time step. For example, if the preceding ON interval of the third fluid valve 131 is set to be relatively long, the opening degree of the third fluid valve 131 in the current time step can be controlled to be opened to a relatively small width. If the preceding ON interval of the third fluid valve 131 is set to be relatively short, the opening degree of the third fluid valve 131 in the current time step can be controlled to be opened to a relatively wide width. For example, in one embodiment of the present invention, if the ON interval of the preceding third fluid valve 131 is set to be relatively long, the internal pressure of the heating funnel 10 is in a relatively strong negative pressure state. Therefore, considering the driving load of the negative pressure source NS due to suction from the heating funnel 10 in a strong negative pressure state, the opening of the third fluid valve 131 is controlled to be opened to a narrow width. Conversely, if the ON interval of the preceding third fluid valve 131 is set to be relatively short, the internal pressure of the heating funnel 10 is in a relatively weak negative pressure state. Therefore, without considering the driving load of the negative pressure source NS due to suction from the heating funnel 10 in a weak negative pressure state, the opening of the third fluid valve 131 can be controlled to be opened to a wide width.

[0152] Referring to Figure 15, the coating volume per unit time, which is set according to the transfer path and transfer speed of the first discharge nozzle 10a, can be calculated by multiplying the cross-sectional area of ​​the scanline SL, which includes the width w dimension and height h dimension of the scanline SL that form the transfer path of the first discharge nozzle 10a, by the length L of the scanline SL per unit time, which corresponds to the transfer speed.

[0153] Although the present invention has been described with reference to embodiments illustrated in the accompanying drawings, these are merely illustrative, and those skilled in the art will understand that a variety of modifications and equivalent other embodiments are possible therefrom. [Industrial applicability]

[0154] The present invention can be applied to industrial fields related to 3D printing apparatus and 3D printing apparatus.

Claims

1. A first discharge nozzle for dispensing a first liquid phase material to form an object on the stage, A heating funnel to which the first discharge nozzle is connected and which is filled with a first liquid material, A multiphase three-dimensional printing apparatus comprising: a bidirectional pressure control unit connected to the heating funnel, which alternately reverses the pressure difference between the inside and outside of the heating funnel between positive and negative pressure, i) accelerates the flow of the first material flowing from the heating funnel toward the first discharge nozzle by positive pressure, and ii) decelerates or brakes the flow of the first material flowing from the heating funnel toward the first discharge nozzle by negative pressure.

2. The multiphase three-dimensional 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, thereby braking the flow of the first material from the heating funnel toward the first discharge nozzle.

3. The multiphase three-dimensional 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 a negative pressure pulse including the application and interruption of negative pressure, and provides an insulation force toward the heating funnel so that the flow of the first material is not discharged from the heating funnel toward the first discharge nozzle.

4. The aforementioned bidirectional pressure control unit is The multiphase three-dimensional printing apparatus according to claim 1, characterized in that, at the end position of the transfer path of the first discharge nozzle or the end position of the scan line forming the transfer path of the first discharge nozzle, the pressure difference between the inside and outside of the heating funnel is set to a negative pressure or a negative pressure pulse including the application and interruption of negative pressure.

5. The aforementioned bidirectional pressure control unit is The multiphase three-dimensional printing apparatus according to claim 1, characterized in that, along the transfer path of the first discharge nozzle or the scan line forming the transfer path of the first discharge nozzle, the pressure difference between the inside and outside of the heating funnel in the section between the end position of the scan line and the start position of the scan line is set to a negative pressure or a negative pressure pulse including the application and interruption of negative pressure.

6. When forming an object by accumulating the preceding turn and the succeeding turn, and by stacking the preceding and succeeding layers, The multiphase three-dimensional printing apparatus according to claim 1, characterized in that, along the transfer path of the first discharge nozzle, the end position and start position of the scan line forming the transfer path of the first discharge nozzle are interposed between the preceding turn and the succeeding turn, and between the preceding layer and the succeeding layer.

7. Along the transfer path of the first discharge nozzle, Between the end position of the scanline in the preceding turn and the start position of the scanline in the following turn, A coating interruption section is formed between the end position of the scan line in the preceding layer and the start position of the scan line in the following layer. The multiphase three-dimensional printing apparatus according to claim 6, 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 a negative pressure pulse including the application and interruption of negative pressure during the coating interruption section.

8. The system further includes a second discharge nozzle for dispensing a second material to form the contour of the molded object, The multiphase three-dimensional 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 a negative pressure pulse including the application and interruption of negative pressure, so as to interrupt the discharge of the first material when the second material is discharged.

9. A drive section of the first discharge nozzle in which the first and second discharge nozzles, which are bound together, are transported together along the transport path of the first discharge nozzle, The drive section of the second discharge nozzle, in which the first and second discharge nozzles, which are bound together, are transported together along the transport path of the second discharge nozzle, The multiphase three-dimensional printing apparatus according to claim 8, characterized in that the molding process for forming a shaped object is divided into mutually exclusive time slots.

10. The aforementioned bidirectional pressure control unit is A first fluid tube connected to the heating funnel, and a first fluid valve for disconnecting and reconnecting the first fluid tube, A second fluid pipe connected to a positive pressure source, and a second fluid valve for disconnecting the connection of the second fluid pipe, A third fluid pipe connected to a negative pressure source, and a third fluid valve for disconnecting the connection of the third fluid pipe, Includes a valve controller for controlling the first to third fluid valves, The multiphase three-dimensional printing apparatus according to claim 1, characterized in that the valve controller implements on / off control for the second fluid valve and on / off control for the third fluid valve.

11. The valve controller is The multiphase three-dimensional printing apparatus according to claim 10, characterized in that the on / off switching of the second fluid valve and the on / off switching of the third fluid valve are controlled alternately with respect to each other, but either partially overlapping with each other along the time axis or exclusively alternating without overlapping with each other.

12. The multiphase three-dimensional printing apparatus according to claim 10, characterized in that the valve controller implements the on / off and opening degree control of the second fluid valve and the on / off and opening degree control of the third fluid valve.

13. The valve controller is The multiphase three-dimensional printing apparatus according to claim 12, characterized in that it implements sequential on / off control of the third fluid valve along with control to reduce the opening degree of the second fluid valve.

14. The valve controller is To control the opening of the second fluid valve, a control signal with a sloped ramp waveform having a first rising time or a first falling time is output. The multiphase three-dimensional printing apparatus according to claim 13, characterized in that it outputs a control signal of a pulse waveform having a second rise period or a second fall time that is shorter than the first rise time or first fall time, for sequential on / off control of the third fluid valve.

15. The aforementioned bidirectional pressure control unit is Depending on the transfer path and transfer speed of the first discharge nozzle, the pressure difference between the inside and outside of the heating funnel is set to a positive pressure in response to the insufficient coating volume of the first material per unit time, thereby accelerating the flow of the first material from the heating funnel toward the first discharge nozzle, or, The multiphase three-dimensional printing apparatus according to claim 1, characterized in that, in accordance with the transfer path and transfer speed of the first discharge nozzle, the pressure difference between the inside and outside of the heating funnel is set to a negative pressure in accordance with the excess coating volume per unit time of the second material, and the flow of the first material flowing from the heating funnel toward the first discharge nozzle is reduced or braked.

16. Depending on the transfer path and transfer speed of the first discharge nozzle, the pressure difference between the inside and outside of the heating funnel is set to positive or negative pressure according to the coating volume of the first material per unit time, thereby accelerating, decreasing, or braking the flow of the first material from the heating funnel toward the first discharge nozzle. The multiphase three-dimensional printing apparatus according to claim 15, characterized in that the coating volume of the first material per unit time is calculated by multiplying the width of the scan line forming the transport path or the cross-sectional area of ​​the scan line including the width dimension and height dimension of the scan line by the length of the scan line per unit time corresponding to the transport speed.

17. The heating funnel includes a circumferential surface that is wider at the top and narrower at the bottom, with an inner diameter that gradually decreases from the inlet at the upper end into which the metal block of the first material is inserted, to the bottleneck portion connected to the first discharge nozzle at the lower end from which the liquid phase of the first material is discharged. The multiphase three-dimensional printing apparatus according to claim 1, characterized in that, with respect to the flow of the liquid phase of the first material, the fluid friction acting on the circumferential surface of the heating funnel and the bottleneck portion that limits the flow rate of the first material cause a pressure loss on the flow of the first material.

18. The multiphase three-dimensional printing apparatus according to claim 17, characterized in that, as the first material, which is filled inside the heating funnel in a limited capacity, is discharged from the inside of the heating funnel onto an external stage, the pressure loss caused in the flow of the first material from the inside of the heating funnel to the outside is reduced.

19. The aforementioned bidirectional pressure control unit is Under a steady state in which the amount of the first material discharged from the inside of the heating funnel toward the external stage is kept constant, i) To offset the pressure loss that decreases with the discharge of the first material, the pressure difference between the inside and outside of the heating funnel decreases, or ii) The discharge of the first material causes the decrease in the weight of the first material and the decrease in pressure loss, which act in opposing directions with respect to the flow of the first material, to cancel each other out, so that the pressure difference between the inside and outside of the heating funnel is maintained equal. The multiphase three-dimensional printing apparatus according to claim 18, characterized in that it controls the pressure difference between the inside and outside of the heating funnel.

20. A seal cover that covers and seals the opening at the upper end of the heating funnel, and which is coupled opposite to the heating funnel, The multiphase three-dimensional printing apparatus according to claim 1, further comprising a sealing gasket for sealing the space between the heating funnel and the sealing cover between the heating funnel and the sealing cover.

21. The heating funnel includes a sealing flange formed along the outer edge of the inlet at the upper end, The multiphase three-dimensional printing apparatus according to claim 20, characterized in that the seal gasket is interposed between the seal flanges of the heating funnels and the seal cover, which are joined facing each other by fastening means that penetrate the seal flanges of the heating funnels and the plate-shaped seal cover, which are formed side by side.

22. The aforementioned bidirectional pressure control unit is A first fluid tube extending from a common confluence point toward the heating funnel, A second fluid pipe connected to a positive pressure source from a common confluence point, The multiphase three-dimensional printing apparatus according to claim 1, further comprising a third fluid pipe connected to a negative pressure source from a common confluence point.

23. The aforementioned bidirectional pressure control unit is On the first fluid pipe, a first fluid valve is connected between the common confluence point and the heating funnel, On the first fluid tube, a first pressure gauge is connected between the heating funnel and the first fluid valve, On the second fluid pipe, a second fluid valve is connected between the common confluence point and the positive pressure source, On the second fluid tube, a second pressure gauge is connected between the positive pressure source and the second fluid valve, On the third fluid pipe, a third fluid valve is connected between the common junction and the negative pressure source, The multiphase three-dimensional printing apparatus according to claim 22, further comprising a third pressure gauge connected between the negative pressure source and the third fluid valve on the third fluid pipe.

24. The aforementioned bidirectional control unit is The multiphase three-dimensional printing apparatus according to claim 23, further comprising a valve controller connected to each of the first to third fluid valves for applying control signals to each of the first to third fluid valves for controlling the opening and closing and degree of opening of the valves.

25. The valve controller is The first and second fluid valves are controlled to open so that the pressure difference between the inside and outside of the heating funnel is set to a positive pressure. The multiphase three-dimensional printing apparatus according to claim 24, characterized in that the first and third fluid valves are controlled to open so that the pressure difference between the inside and outside of the heating funnel is set to a negative pressure.

26. The device further includes a second discharge nozzle for dispensing a paste-like or slurry-like second material that forms the contour of the molded object. The multiphase three-dimensional printing apparatus according to claim 1, characterized in that the width of the scan line forming the transfer path of the first discharge nozzle is set to scan the entire printing region in which the printed object is formed, which corresponds to the filling space surrounded by the contour of the printed object formed from the second material.

27. The multiphase three-dimensional printing apparatus according to claim 26, further comprising an extrusion device connected to the second discharge nozzle, which extrudes the second material toward the second discharge nozzle so as to discharge a paste-like or slurry-like second material having a mixture of ceramic particles and a matrix in which ceramic particles are dispersed.

28. The system further includes a heating chamber for providing a slow-cooling space for the first and second materials accumulated on the stage from the first and second discharge nozzles, while housing the stage. The multiphase three-dimensional printing apparatus according to claim 26, characterized in that the pressure difference between the inside and outside of the heating funnel corresponds to the internal pressure of the heating funnel containing the liquid phase first material, with respect to the atmospheric pressure of the slow-cooling space of the heating chamber.

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