High-temperature molten metal droplet spray head, and 3D printer and control method therefor

Abstract

A high-temperature molten metal droplet spray head (10), comprising a spray head body (1) and a nozzle (2), a vertically-penetrating wire-feeding channel (3) being formed in the spray head body (1), part of a wall of the wire-feeding channel (3) being configured as an induction heated portion, the nozzle (2) being arranged in the wire-feeding channel (3) and being configured to come into contact with the induction heated portion, a vertically-penetrating liquid-dripping hole (21) being provided in the nozzle (2), the liquid-dripping hole (21) being configured to be in the form of an inverted cone, and the induction heated portion being configured to be inductively heated so as to transfer heat to the nozzle and thus heat a metal wire in the liquid-dripping hole (21). By means of the present invention, it is easy for the high-temperature molten metal droplet spray head (10) to control the formation and dripping of metal droplets, and the problems of blockage and overflow of molten metal are less likely to occur, thereby improving the printing quality and efficiency. The present invention further relates to a 3D printer (100) and a control method therefor.

Description

High-temperature molten metal droplet nozzle, 3D printer and control method thereof Technical Field

[0001] The present invention relates to the technical field of 3D printers, and in particular to a high-temperature molten metal droplet nozzle, a 3D printer and a control method thereof. Background Art

[0002] A 3D printer is a device that gradually builds up a desired shape from raw materials like metal, ceramic, or plastic. Metal is the most widely used of these materials. The printhead is a crucial component of a metal 3D printer, heating the metal to a molten state before dripping it onto the print platform to form the part.

[0003] Currently, nozzles usually take the form of crucibles. After the metal is heated to a molten state in the crucible, it will naturally drip onto the printing platform. However, this type of nozzle makes it difficult to control the specific formation and dripping process of the molten metal droplets, and is prone to molten metal blockage and overflow, affecting printing quality and efficiency.

[0004] Summary of the Invention

[0005] The problem solved by the present invention is how to improve printing quality and efficiency.

[0006] In order to solve the above problems, the present invention provides a high-temperature metal molten liquid droplet nozzle, which includes a nozzle body and a nozzle. A wire feeding channel is formed on the nozzle body, which runs through the upper and lower parts. Part of the wall of the wire feeding channel is set as an induction heating part. The nozzle is arranged in the wire feeding channel and is arranged in contact with the induction heating part. A drip hole is opened on the nozzle which runs through the upper and lower parts. The drip hole is set in an inverted cone shape. The induction heating part is used to be inductively heated to transfer heat to the nozzle to heat the metal wire in the drip hole.

[0007] In the high-temperature molten metal droplet nozzle provided by the present invention, a wire feeding channel that runs through the nozzle body from top to bottom is formed, and a drip hole that runs through the nozzle from top to bottom is opened on the nozzle body. Thus, the wire feeding channel and the drip hole constitute the main threading area of ​​the metal wire. When the metal wire is fed into the nozzle from top to bottom, it will first enter the wire feeding channel from the upper port of the wire feeding channel, and finally pass through the drip hole of the nozzle in the wire feeding channel. In this way, when metal droplets need to be generated, the metal wire is controlled to enter the wire feeding channel of the nozzle body until it extends into the drip hole. Under the contact heat transfer effect of the nozzle, the head of the metal wire in the drip hole will melt first and gather in the drip hole. At this time, due to the inverted cone design of the drip hole, the molten metal will not fall out of the drip hole directly. At this time, the movement of the metal wire can be controlled as needed to force the molten metal to flow out of the drip hole, so that the molten metal forms droplets at the lower port of the drip hole and drips. In this way, metal droplets can be generated on demand, the formation and dripping of metal droplets are easy to control, and the problem of molten metal blockage and overflow is not easy to occur, thereby improving printing quality and efficiency.

[0008] Optionally, the nozzle body includes an upper cover, a lower cover, a connecting bolt, a connecting nut and a connecting body. The upper cover and the lower cover are spaced apart from each other, and the upper cover and the lower cover are respectively provided with a first through hole and a second through hole arranged coaxially. The connecting bolt passes through the first through hole and the second through hole, and the connecting nut is connected to the connecting bolt to fix the upper cover and the lower cover. The connecting body is clamped between the upper cover and the lower cover, and the wire feeding channel includes a wire feeding hole formed in the upper cover, a heating hole formed in the connecting body, and a dripping hole formed in the lower cover.

[0009] Optionally, the connector includes an upper guide column and a base plate connected up and down, the base plate constitutes the induction heating part, the heating hole includes an upper hole formed in the upper guide column and a lower hole formed in the base plate, and the nozzle is arranged at the connection between the upper hole and the lower hole.

[0010] Optionally, an annular rib is provided on the peripheral wall of the nozzle, and an annular groove which is embedded and matched with the annular rib is provided at the connection between the upper hole and the lower hole.

[0011] Optionally, the upper cover, the lower cover and the upper guide column are made of quartz, the connecting bolts and the connecting nuts are made of ceramic, the base plate is made of graphite, and the nozzle is made of tungsten carbide.

[0012] Optionally, the lower end of the nozzle extends into the dripping hole, and the aperture of the lower hole is smaller than the aperture of the dripping hole.

[0013] Optionally, the high-temperature molten metal droplet nozzle is made of a high-temperature resistant material.

[0014] The present invention also provides a high-temperature molten metal droplet 3D printer, which includes a frame, a printing platform, a wire feeder, an induction heater and the high-temperature molten metal droplet nozzle as described above. The printing platform is arranged on the frame, the wire feeder is arranged on the frame and is located above the printing platform, the induction heater is arranged on the frame, and the induction heating coil of the induction heater extends between the printing platform and the wire feeder. The induction heating coil is arranged in a ring shape and extends axially in the up and down directions. The high-temperature molten metal droplet nozzle is passed through the induction heating coil.

[0015] The high-temperature metal molten droplet 3D printer provided by the present invention comprises the following steps: a printing platform is arranged on a frame so that molten droplets drip and deposit to form printed parts; a wire feeder is arranged on the frame and located above the printing platform so as to supply metal wire to the high-temperature metal molten droplet nozzle; an induction heater is arranged on the frame, an induction heating coil of the induction heater extends between the printing platform and the wire feeder, and the high-temperature metal molten droplet nozzle is penetrated by the induction heating coil so as to inductively heat the induction heating portion of the high-temperature metal molten droplet nozzle. In this way, when using the printer for 3D printing, the induction heater can first be used to induction heat the induction heating portion to transfer heat to the nozzle, and then the wire feeder is used to feed the metal wire into the wire feeding channel of the nozzle body until it extends into the drip hole, so that the metal wire head melts in the drip hole, and the molten droplets drip from the lower end of the drip hole of the nozzle to the printing platform. The dripping and deposition of the molten droplets on the printing platform are repeatedly controlled to complete the printing. The formation and dripping of the metal droplets are easy to control, and the printing quality and efficiency are high.

[0016] Optionally, the height of the induction heating portion of the high-temperature molten metal droplet nozzle relative to the printing platform is equal to the height of the induction heating coil relative to the printing platform.

[0017] Optionally, the printer also includes a platform heater, the frame has an up and down direction, a first horizontal direction and a second horizontal direction perpendicular to each other, the printing platform is used to move relative to the frame along the up and down direction, the first horizontal direction and the second horizontal direction, the platform heater is arranged inside the printing platform, and is used to heat the printing platform, the high-temperature molten metal droplet nozzle is arranged above the printing platform, the wire feeder is arranged above the high-temperature molten metal droplet nozzle, and is used to feed metal wire into the wire feeding channel of the high-temperature molten metal droplet nozzle, and the induction heater is used to induction heat the metal wire in the wire feeding channel.

[0018] Optionally, the printer also includes a three-dimensional motion platform, the three-dimensional motion platform includes a lifting frame and a two-dimensional motion platform, the lifting frame is installed on the frame, the two-dimensional motion platform is installed on the upper end of the lifting frame, the printing platform is arranged at the upper end of the two-dimensional motion platform, and the printing platform is movably installed on the frame along the up and down directions, the first horizontal direction and the second horizontal direction through the three-dimensional motion platform.

[0019] Optionally, the printing platform includes a base and a platform body, the upper end of the base is provided with a support column, and the platform body is provided at the upper end of the support column.

[0020] Optionally, the platform body includes a bottom shell and a printing platform plate, the bottom shell is arranged at the upper end of the support column and has an upward-opening installation cavity, the printing platform plate cover is arranged at the opening of the installation cavity, and the platform heater is arranged inside the installation cavity and connected to the printing platform plate.

[0021] Optionally, the printer further includes a platform radiator, wherein the platform radiator is provided between the base and the platform body.

[0022] Optionally, the printing platform plate is made of high-temperature resistant material.

[0023] Optionally, the printer further includes a platform thermometer, which is disposed inside the installation cavity and is used to detect the temperature of the printing platform plate.

[0024] Optionally, two mounting rods are installed on the frame, the two mounting rods are located above the printing platform and are spaced apart along the second horizontal direction, and the high-temperature molten metal droplet nozzle is clamped between the two mounting rods.

[0025] The present invention also provides a control method for the high-temperature molten metal droplet 3D printer as described above, the control method comprising:

[0026] Induction heating the induction heating portion by an induction heater to transfer heat to the nozzle;

[0027] Feeding a metal wire into a wire feeding channel of the nozzle body through a wire feeder until the wire extends into the dripping hole of the nozzle, so that the metal wire contacts the nozzle and is heated;

[0028] When the head of the metal wire in the drip hole is melted, the metal wire is fed downward by the wire feeder until a molten droplet is formed at the lower end of the drip hole;

[0029] The metal wire is retracted upward by the wire feeder until the molten liquid drops from the lower end of the dripping hole.

[0030] In the control method of the high-temperature metal molten droplet 3D printer provided by the present invention, the downward feeding of the wire feeder can accelerate the formation of the molten droplets, and the upward retraction of the wire feeder can accelerate the breakage of the molten droplets to drip, that is, the formation and dripping of the molten droplets are faster and more efficient.

[0031] Optionally, before the wire is fed into the wire feeding channel of the nozzle body by the wire feeder until it extends into the drip hole of the nozzle so that the wire contacts the nozzle and is heated, the control method further includes: heating the printing platform to a preset temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] FIG1 is a schematic structural diagram of a high-temperature molten metal droplet nozzle according to an embodiment of the present invention;

[0033] FIG2 is an exploded schematic diagram of a high-temperature molten metal droplet nozzle according to an embodiment of the present invention;

[0034] FIG3 is a left side view of a high-temperature molten metal droplet nozzle according to an embodiment of the present invention;

[0035] FIG4 is a cross-sectional view of the high-temperature molten metal droplet nozzle along line AA in FIG3 ;

[0036] FIG5 is an enlarged schematic diagram of a portion B of the high-temperature molten metal droplet nozzle in FIG4 ;

[0037] FIG6 is a schematic structural diagram of a high-temperature molten metal droplet 3D printer according to an embodiment of the present invention;

[0038] FIG7 is a schematic structural diagram of a high-temperature metal molten droplet 3D printer without an inert gas protective shell according to an embodiment of the present invention;

[0039] FIG8 is a rear view of the high-temperature molten metal droplet 3D printer according to an embodiment of the present invention after removing the inert gas protection shell;

[0040] FIG9 is a schematic structural diagram of a printing platform according to an embodiment of the present invention;

[0041] FIG10 is an exploded schematic diagram of a printing platform body according to an embodiment of the present invention;

[0042] FIG11 is a schematic structural diagram of a high-temperature metal molten droplet 3D printer according to an embodiment of the present invention after a portion of the inert gas protection shell is removed;

[0043] FIG12 is a flow chart of a control method for a high-temperature molten metal droplet 3D printer according to an embodiment of the present invention.

[0044] Explanation of Reference Numerals: 10. High-Temperature Molten Metal Droplet Nozzle; 1. Nozzle Body; 11. Upper Cover; 111. First Via Hole; 112. Upper Positioning Groove; 12. Lower Cover; 121. Second Via Hole; 122. Lower Positioning Groove; 13. Connecting Bolt; 14. Connecting Nut; 15. Connector; 151. Upper Guide Post; 152. Bottom Plate; 153. Annular Groove; 2. Nozzle; 21. Drip Hole; 22. Annular Rib; 3. Wire Feed Channel; 31. Wire Feed Hole; 32. Heating Hole; 321. Upper Hole; 322. Lower Hole; 33. Drip Hole; 100. High-Temperature Molten Metal Droplet 3D Printer; 20. Frame; 201. Mounting rod; 30. Print platform; 301. Base; 3011. Support column; 302. Platform body; 3021. Bottom shell; 30211. Mounting cavity; 3022. Print platform plate; 40. Wire feeder; 50. Induction heater; 501. Induction heating coil; 502. Heater body; 60. Platform heater; 70. Three-dimensional motion platform; 701. Lifting frame; 702. Two-dimensional motion platform; 80. Platform radiator; 90. Inert gas protective shell. DETAILED DESCRIPTION

[0045] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0046] In the description of the present invention, it should be understood that if there are terms such as "up", "down", "front", "back", "left" and "right", the orientation or position relationship indicated by them is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, it should not be understood as a limitation on the present invention.

[0047] In addition, in the description of the present invention, the X-axis in the accompanying drawings represents the horizontal direction and is designated as the left and right positions, and the positive direction of the X-axis represents the left, and correspondingly, the reverse direction of the X-axis represents the right; the Y-axis in the accompanying drawings also represents the horizontal direction and is designated as the front and back positions, and the positive direction of the Y-axis represents the front, and correspondingly, the reverse direction of the Y-axis represents the back; the Z-axis in the accompanying drawings represents the vertical direction, that is, the up and down positions, and the positive direction of the Z-axis represents the top, and correspondingly, the reverse direction of the Z-axis represents the bottom. It should be noted that the aforementioned X-axis, Y-axis, and Z-axis are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the present invention.

[0048] Please refer to Figures 1 and 2. An embodiment of the present invention provides a high-temperature molten metal droplet nozzle 10, which includes a nozzle body 1 and a nozzle 2. A wire feeding channel 3 is formed on the nozzle body 1 and runs through it from top to bottom. Part of the wall of the wire feeding channel 3 is set as an induction heating part. The nozzle 2 is arranged in the wire feeding channel 3 (please refer to Figure 4 for the wire feeding channel 3) and is arranged in contact with the induction heating part. A drip hole 21 is opened on the nozzle 2 and runs through it from top to bottom (please refer to Figure 5 for the drip hole 21). The drip hole 21 is set in an inverted cone shape. The induction heating part is used to be inductively heated to transfer heat to the nozzle 2 to heat the metal wire in the drip hole 21.

[0049] In this embodiment, a wire feeding channel 3 that passes through the nozzle body 1 from top to bottom is formed, and a drip hole 21 that passes through the nozzle 2 from top to bottom is opened on the nozzle 2 provided in the wire feeding channel 3, so that the wire feeding channel 3 and the drip hole 21 constitute the main threading area of ​​the metal wire. When the metal wire is fed into the nozzle from top to bottom, it will first enter the wire feeding channel 3 from the upper port of the wire feeding channel 3, and finally pass through the drip hole 21 of the nozzle 2 in the wire feeding channel 3. In this way, when metal droplets need to be generated, the metal wire is controlled to enter the wire feeding channel 3 of the nozzle body 1 until it extends into the drip hole 21. Under the contact heat transfer effect of the nozzle 2, the head of the metal wire in the drip hole 21 will melt first and gather in the drip hole 21. At this time, due to the inverted cone design of the drip hole 21, the molten metal will not fall out of the drip hole 21 directly. At this time, the movement of the metal wire can be controlled as needed to force the molten metal to flow out of the drip hole 21, so that the molten metal forms droplets at the lower port of the drip hole 21 and drips. In this way, metal droplets can be generated on demand, the formation and dripping of metal droplets can be easily controlled, and the problem of molten metal blockage and overflow is not easy to occur, thereby improving printing quality and efficiency.

[0050] Optionally, please refer to Figure 2, the nozzle body 1 includes an upper cover 11, a lower cover 12, a connecting bolt 13, a connecting nut 14 and a connecting body 15, the upper cover 11 and the lower cover 12 are spaced apart from each other, the upper cover 11 and the lower cover 12 are respectively provided with a first through hole 111 and a second through hole 121 coaxially arranged, the connecting bolt 13 passes through the first through hole 111 and the second through hole 121, the connecting nut 14 is connected to the connecting bolt 13 to fix the upper cover 11 and the lower cover 12, the connecting body 15 is clamped between the upper cover 11 and the lower cover 12, the wire feeding channel 3 includes a wire feeding hole 31 formed in the upper cover 11, a heating hole 32 formed in the connecting body 15 and a dripping hole 33 formed in the lower cover 12.

[0051] Specifically, referring to FIG. 3 and FIG. 4 , the diameter of the wire feeding hole 31 is larger than the diameter of the dripping hole 33 , and the diameter of the dripping hole 33 is larger than the diameter of the heating hole 32 .

[0052] In this embodiment, by dividing the nozzle body 1 into an upper cover 11, a lower cover 12, a connecting bolt 13, a connecting nut 14 and a connecting body 15, the upper cover 11, the lower cover 12 and the connecting body 15 can be detachably assembled using the connecting bolts 13 and the connecting nuts 14, which makes disassembly and assembly convenient and easy to repair and replace nozzle parts.

[0053] Optionally, referring to Figures 2 and 4, the connector 15 includes an upper guide column 151 and a bottom plate 152 connected up and down, the bottom plate 152 constitutes the induction heating part, the heating hole 32 includes an upper hole 321 formed on the upper guide column 151 and a lower hole 322 formed on the bottom plate 152, and the nozzle 2 is arranged at the connection between the upper hole 321 and the lower hole 322.

[0054] Specifically, referring to Figure 4 , the lower end of the upper cover 11 is provided with an upper positioning groove 112 that matches the shape of the upper guide post 151. The upper end of the lower cover 12 is provided with a lower positioning groove 122 that matches the shape of the bottom plate 152. The upper positioning groove 112 and the lower positioning groove 122 can be combined to position the connector 15, preventing the connector 15 from moving out of position and improving the structural stability of the entire nozzle. The bottom plate 152 constitutes the induction heating unit, that is, the entire bottom plate 152 serves as the induction heating unit and can be inductively heated, thereby transferring heat to the nozzle 2.

[0055] In this embodiment, by arranging the nozzle 2 at the connection between the upper hole 321 and the lower hole 322, the nozzle 2 is made closer to the lower end of the entire wire feeding channel 3, that is, the position where the molten droplets are formed is closer to the lower end of the entire wire feeding channel 3. When the distance between the nozzle and the printing platform 30 is constant, the position where the molten droplets are formed is relatively low, which can reduce the dripping distance of the droplets and avoid the dripping distance being too long, which may cause the droplets to solidify too quickly.

[0056] Optionally, referring to FIG. 5 , the peripheral wall of the nozzle 2 is provided with an annular rib 22 , and the connection between the upper hole 321 and the lower hole 322 is provided with an annular groove 153 that is embedded and matched with the annular rib 22 .

[0057] In this embodiment, the cooperation between the annular rib 22 and the annular groove 153 can improve the installation stability of the nozzle 2 and ensure the structural stability of the entire nozzle.

[0058] Optionally, referring to FIG2 , the upper cover 11 , the lower cover 12 and the upper guide column 151 are made of quartz, the connecting bolts 13 and the connecting nuts 14 are made of ceramic, the base plate 152 is made of graphite, and the nozzle 2 is made of tungsten carbide.

[0059] Specifically, quartz and ceramics are both high-temperature resistant and resistant to electromagnetic induction heating. The upper guide post 151 is preferably made of quartz that has been precision-machined using ultrasonic machining to prevent cracking. Graphite is thermally insulating and can be heated by electromagnetic induction. Tungsten carbide is an extremely hard, wear-resistant, and high-temperature resistant alloy carbide that can be produced using electrical discharge machining (EDM).

[0060] In this embodiment, by setting the material of the upper cover 11, the lower cover 12 and the upper guide column 151 to quartz, the material of the connecting bolt 13 and the connecting nut 14 to ceramic, the material of the bottom plate 152 to graphite, and the material of the nozzle 2 to tungsten carbide, all components of the nozzle have high temperature resistance and small thermal deformation; at the same time, the bottom plate 152 is made of graphite, which has good thermal insulation performance, can prevent heat loss, and can also be heated by electromagnetic induction, so as to facilitate heat transfer to the nozzle 2.

[0061] Optionally, referring to FIG. 5 , the lower end of the nozzle 2 extends into the dripping hole 33 , and the diameter of the lower hole 322 is smaller than that of the dripping hole 33 .

[0062] In this embodiment, by making the aperture of the lower hole 322 smaller than that of the dripping hole 33, the dripping hole 33 has a larger aperture than the lower hole 322, which facilitates observation of the droplets formed at the lower end of the nozzle 2 and facilitates temperature measurement.

[0063] Optionally, the high-temperature molten metal droplet nozzle 10 is made of a high-temperature resistant material.

[0064] In this embodiment, the high-temperature molten metal droplet nozzle 10 is made of a high-temperature resistant material with good high-temperature resistance, thereby avoiding thermal deformation caused by contact with the molten metal wire.

[0065] Please refer to Figure 6. An embodiment of the present invention further provides a high-temperature molten metal droplet 3D printer 100, which includes a frame 20, a printing platform 30, a wire feeder 40, an induction heater 50 and the high-temperature molten metal droplet nozzle 10 as described above. The printing platform 30 is arranged on the frame 20, the wire feeder 40 is arranged on the frame 20, and is located above the printing platform 30. The induction heater 50 is arranged on the frame 20, and the induction heating coil 501 of the induction heater 50 extends between the printing platform 30 and the wire feeder 40. The induction heating coil 501 is arranged in a ring shape, and its axial direction extends in the up and down directions. The high-temperature molten metal droplet nozzle 10 is passed through the induction heating coil 501.

[0066] Specifically, referring to FIG7 , the induction heater 50 includes a heater body 502 and an induction heating coil 501. The heater body 502 is disposed on the frame 20, and the induction heating coil 501 is electrically connected to the heater body 502. More specifically, the heater body 502 may include a power conversion module, an internal circulation cooling module, and a control module. The induction heating coil 501 is electrically connected to the power conversion module, and the power conversion module outputs current to the induction heating coil 501. The induction heating coil 501, which receives the current, can induction heat the induction heating portion of the high-temperature molten metal droplet nozzle 10.

[0067] In this embodiment, the printing platform 30 is arranged on the frame 20 so that the molten liquid droplets drip and deposit to form printed parts; the wire feeder 40 is arranged on the frame 20 and is located above the printing platform 30 to supply metal wire to the high-temperature metal molten droplet nozzle 10; the induction heater 50 is arranged on the frame 20, the induction heating coil 501 of the induction heater 50 extends between the printing platform 30 and the wire feeder 40, and the high-temperature metal molten droplet nozzle 10 is passed through the induction heating coil 501 so as to induction heat the induction heating part of the high-temperature metal molten droplet nozzle 10. In this way, when using this printer for 3D printing, the induction heater 50 can be used to induction heat the induction heating part to transfer heat to the nozzle, and then the wire feeder 40 can be used to feed the metal wire into the wire feeding channel 3 of the nozzle body 1 until it extends into the drip hole 21, so that the head of the metal wire is melted in the drip hole 21, and the molten droplets drip from the lower end of the drip hole 21 of the nozzle 2 to the printing platform 30. The dripping and deposition of the molten droplets on the printing platform 30 are repeatedly controlled to complete the printing. The formation and dripping of metal droplets are easy to control, and the printing quality and efficiency are high.

[0068] Optionally, the height of the induction heating portion of the high-temperature molten metal droplet nozzle 10 relative to the printing platform 30 is equal to the height of the induction heating coil 501 relative to the printing platform 30 .

[0069] In this embodiment, by making the height of the induction heating portion equal to the height of the induction heating coil 501 , the induction heating coil 501 can heat the induction heating portion accurately.

[0070] Current metal 3D printers typically use selective laser sintering printers, but this type of printer requires metal powder as raw material. The powder is highly dangerous and is not conducive to large-scale popularization.

[0071] In view of this, please refer to Figure 7. The printer also includes a platform heater 60. The frame 20 has an up and down direction, a first horizontal direction and a second horizontal direction perpendicular to each other. The printing platform 30 is used to move relative to the frame 20 along the up and down direction, the first horizontal direction and the second horizontal direction. The platform heater 60 is arranged inside the printing platform 30 and is used to heat the printing platform 30. The high-temperature molten metal droplet nozzle 10 is arranged above the printing platform 30. The wire feeder 40 is arranged above the high-temperature molten metal droplet nozzle 10 and is used to feed metal wire into the wire feeding channel 3 of the high-temperature molten metal droplet nozzle 10. The induction heater 50 is used to induction heat the metal wire in the wire feeding channel 3.

[0072] Specifically, referring to FIG7 , the specific orientation of the up-down direction is not limited and, for example, can be the Z-axis direction as shown in the figure. The specific orientations of the first horizontal direction and the second horizontal direction are not limited and can be any two mutually perpendicular directions in the horizontal plane. For example, the first horizontal direction can be the Y-axis direction as shown in the figure, and the second horizontal direction can be the X-axis direction as shown in the figure.

[0073] In this embodiment, the printing platform 30 is used to move relative to the frame 20 in the up-down direction, the first horizontal direction and the second horizontal direction, that is, the printing platform 30 can move in three directions on the frame 20, namely, the up-down direction, the first horizontal direction and the second horizontal direction. Specifically, the printing platform 30 can move in the X-axis, Y-axis and Z-axis on the frame 201; at the same time, the printing platform 30 is heated by arranging a platform heater 60 inside the printing platform 30; in addition, the high-temperature metal molten droplet nozzle 10 is arranged above the printing platform 30 so as to serve as a container for heating the metal wire; in addition, the wire feeder 40 is arranged above the high-temperature metal molten droplet nozzle 10 to feed the metal wire into the wire feeding channel 3 of the high-temperature metal molten droplet nozzle 10; finally, the metal wire in the wire feeding channel 3 is induction heated by the induction heater 50. When using this printer for 3D printing, the printing platform 30 is first heated to a preset temperature. A wire is then fed through the wire feeder 40 into the wire feed channel 3 of the high-temperature molten metal droplet nozzle 10. The metal wire is inductively heated by the induction heater 50 within the wire feed channel 3 until it melts and forms droplets. The droplets then drip onto the printing platform 30 below. As the printing platform 30 continues to move, the continuously dripping droplets deposit on the printing platform 30 to form a 3D printed part, ultimately completing the 3D print. This printer utilizes molten droplet technology for 3D printing, eliminating the need for metal powder as a raw material. This provides increased safety and facilitates widespread adoption. The printing platform 30 can be heated to a higher temperature by the platform heater 60, reducing the temperature difference between the printing platform 30 and the droplets. This prevents both thermal cracking caused by sudden temperature changes when the droplets land on the printing platform 30 and phase transition lines that affect part strength due to rapid solidification of the front and rear droplets, thereby improving the quality of the printed parts.

[0074] Optionally, referring to Figures 7 and 8, the printer also includes a three-dimensional motion platform 70, which includes a lifting frame 701 and a two-dimensional motion platform 702. The lifting frame 701 is installed on the frame 20, and the two-dimensional motion platform 702 is installed on the upper end of the lifting frame 701. The printing platform 30 is arranged on the upper end of the two-dimensional motion platform 702, and the printing platform 30 is movably installed on the frame 20 along the up and down directions, the first horizontal direction and the second horizontal direction through the three-dimensional motion platform 70.

[0075] It is understood that the lifting frame 701 can be raised and lowered to drive the printing platform 30 to move in the vertical direction, and the two-dimensional motion platform 702 can move in the first and second horizontal directions on the horizontal plane to drive the printing platform 30 to move in the first and second horizontal directions. There is no specific limitation on the specific implementation of the two-dimensional motion platform 702. For example, the two-dimensional motion platform 702 can be configured as a first slide and a second slide connected to each other, with the first slide connected to the lifting frame 701 and the second slide connected to the printing platform 30. The sliding direction of the first slide is the first horizontal direction, and the sliding direction of the second slide is the second horizontal direction. In this way, the printing platform 30 can be driven to move in the first and second horizontal directions.

[0076] In this embodiment, the combination of the lifting frame 701 and the two-dimensional motion platform 702 enables the printing platform 30 to move in three directions, namely, the up and down direction, the first horizontal direction, and the second horizontal direction, with high positioning accuracy, which is beneficial to the quality of printed parts.

[0077] Optionally, referring to FIG. 8 and FIG. 9 , the printing platform 30 includes a base 301 and a platform body 302 . A support column 3011 is provided at the upper end of the base 301 , and the platform body 302 is provided at the upper end of the support column 3011 .

[0078] In this embodiment, the printing platform 30 is composed of a base 301 and a platform body 302 , and has a simple structure and low cost.

[0079] Optionally, referring to Figure 10, the platform body 302 includes a bottom shell 3021 and a printing platform plate 3022, the bottom shell 3021 is arranged at the upper end of the support column 3011, and has an upward-opening installation cavity 30211, the printing platform plate 3022 is covered at the opening of the installation cavity 30211, and the platform heater 60 is arranged inside the installation cavity 30211 and connected to the printing platform plate 3022.

[0080] Specifically, the platform heater 60 can be a heating plate that contacts the print platform plate 3022 to heat the print platform plate 3022. The platform body 302 includes a bottom shell 3021 and a print platform plate 3022. The print platform plate 3022 can be heated to a preset temperature by the platform heater 60. Once the molten liquid drops onto the print platform plate 3022, they are deposited on the print platform plate 3022 to form a 3D printed part.

[0081] In this embodiment, by setting the platform heater 60 in the installation cavity 30211a of the bottom shell 3021, that is, setting the platform heater 60 in a closed space, the heat loss of the platform heater 60 can be reduced and the heating effect on the printing platform plate 3022 can be ensured.

[0082] Optionally, referring to FIG. 9 , the printer further includes a platform radiator 80 , which is disposed between the base 301 and the platform body 302 .

[0083] Specifically, the platform radiator 80 may be a water cooler.

[0084] In this embodiment, by providing a platform radiator 80 , the platform radiator 80 can perform cooling and heat dissipation, so as to dissipate heat to the platform body 302 in time when needed, thereby achieving rapid cooling of the printing platform 30 .

[0085] Optionally, referring to FIG. 10 , the printing platform plate 3022 is made of a high-temperature resistant material.

[0086] Specifically, high temperature resistant materials generally refer to materials that can withstand temperatures above 1580° C. High temperature resistant materials may be refractory bricks or the like.

[0087] In this embodiment, the material of the printing platform plate 3022 is set to a high-temperature resistant material. Compared with the conventional printing platform plate 3022 using metal as the material, the printing platform plate 3022 of this solution is less likely to warp when heated, which is conducive to 3D printing.

[0088] Optionally, referring to FIG. 10 , the printer further includes a platform thermometer, which is disposed inside the mounting cavity 30211 and is used to detect the temperature of the printing platform plate 3022 .

[0089] Specifically, the platform temperature meter can be set as a thermocouple, which is in contact with the printing platform plate 3022 to detect the temperature of the printing platform plate 3022.

[0090] In this embodiment, by providing a platform thermometer, the temperature of the printing platform plate 3022 can be monitored in real time to prevent the temperature of the printing platform plate 3022 from being too low and affecting the quality of the printed parts.

[0091] Optionally, referring to Figures 7 and 8, two mounting rods 201 are installed on the frame 20, the two mounting rods 201 are located above the printing platform 30, and are spaced apart along the second horizontal direction, and the high-temperature metal molten droplet nozzle 10 is clamped between the two mounting rods 201.

[0092] In this embodiment, the high-temperature molten metal droplet nozzle 10 is clamped by two mounting rods 201 to achieve the installation of the high-temperature molten metal droplet nozzle 10 on the frame 20. The structure is simple, making the high-temperature molten metal droplet nozzle 10 easy to disassemble and assemble.

[0093] Optionally, referring to Figure 11, the printer also includes an inert gas protection shell 90, which covers the above-mentioned frame 20, printing platform 30, platform heater 60, high-temperature molten metal droplet nozzle 10, wire feeder 40 and induction heater 50. This arrangement can provide a closed space for 3D printing to prevent inert gas leakage.

[0094] Referring to FIG. 12 , an embodiment of the present invention further provides a control method for the high-temperature molten metal droplet 3D printer as described above. The control method includes:

[0095] Step S10 : induction heating the induction heating portion by the induction heater 50 to transfer heat to the nozzle 2 .

[0096] In step S10 , after the induction heater 50 induction heats the induction heating portion, the induction heating portion transfers heat to the nozzle 2 in contact therewith.

[0097] Step S20: feeding the metal wire into the wire feeding channel 3 of the nozzle body 1 through the wire feeder 40 until the wire extends into the dripping hole 21 of the nozzle 2, so that the metal wire contacts the nozzle 2 and is heated.

[0098] In step S20 , after the wire is inserted into the dripping hole 21 , the head of the wire in the dripping hole 21 is preferentially melted and gathered in the dripping hole 21 due to the contact heat transfer effect of the nozzle 2 .

[0099] Step S30 : When the head of the metal wire in the dripping hole 21 is melted, the metal wire is fed downward by the wire feeder 40 until a molten droplet is formed at the lower end of the dripping hole 21 .

[0100] It should be noted that the molten metal itself has a large surface tension. Therefore, as the metal wire is fed downward, the molten metal is subjected to a large downward pressure and is forced out of the drip hole 21 under the pressure to form droplets at the lower end of the drip hole 21. To ensure the formation of droplets, the wire feeder 40 can adopt a relatively fast feeding speed when feeding downward.

[0101] Step S40 : retracting the metal wire upward through the wire feeder 40 until the molten liquid drops from the lower end of the dripping hole 21 .

[0102] As the metal wire is retracted upward, a momentary vacuum is generated above the molten droplet, causing the molten droplet to break off from the molten metal above and drip, without waiting for the molten droplet to break off naturally. To accelerate the droplet breakage, the wire feeder 40 can be retracted upward at a faster speed.

[0103] In this embodiment, the downward feeding of the wire feeder 40 can accelerate the formation of the molten droplets, and the upward retraction of the wire feeder 40 can accelerate the breakage of the molten droplets to drip, that is, the formation and dripping of the molten droplets are faster and more efficient.

[0104] Optionally, before the metal wire is fed into the wire feeding channel 3 of the nozzle body 1 by the wire feeder 40 until it extends into the drip hole 21 of the nozzle 2 so that the metal wire contacts the nozzle 2 and is heated, the control method also includes: heating the printing platform 30 to a preset temperature.

[0105] Specifically, the preset temperature is the temperature actually required for on-site printing, which is not limited here. The printing platform 30 can be heated by turning on a platform heater installed in the printing platform 30.

[0106] In this embodiment, by heating the printing platform 30 to a preset temperature before formally heating the molten metal wire, it is possible to ensure that the dripping position of the droplet is in a relatively high temperature environment, thereby preventing the droplet from solidifying too quickly and affecting the printing quality.

[0107] In the description of the present invention, the terms "first," "second," etc. are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one of the features.

[0108] Additionally, in the description of the present invention, the term "embodiment" means that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or implementation are included in at least one embodiment or implementation of the present invention. In the present invention, schematic representations of the above terms do not necessarily refer to the same embodiment or implementation. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or implementations.

[0109] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A high temperature molten metal droplet nozzle (10), characterized in that: The nozzle comprises a nozzle body (1) and a nozzle (2), wherein the nozzle body (1) is formed with a wire feeding channel (3) which passes through the nozzle body from top to bottom, a part of the wall of the wire feeding channel (3) is arranged as an induction heating portion, the nozzle (2) is arranged in the wire feeding channel (3) and is arranged in contact with the induction heating portion, the nozzle (2) is provided with a drip hole (21) which passes through the nozzle from top to bottom, the drip hole (21) is arranged in an inverted cone shape, and the induction heating portion is used for being inductively heated so as to transfer heat to the nozzle (2) and heat the metal wire in the drip hole (21).

2. The high-temperature molten metal droplet nozzle (10) according to claim 1, characterized in that: The nozzle body (1) comprises an upper cover (11), a lower cover (12), a connecting bolt (13), a connecting nut (14) and a connecting body (15); the upper cover (11) and the lower cover (12) are arranged with an interval up and down; the upper cover (11) and the lower cover (12) are respectively provided with a first through hole (111) and a second through hole (121) which are arranged coaxially; the connecting bolt (13) passes through the first through hole (111) and the second through hole (121); the connecting nut (14) is connected to the connecting bolt (13) so that the upper cover (11) and the lower cover (12) are fixedly connected; the connecting body (15) is clamped between the upper cover (11) and the lower cover (12); the wire feeding channel (3) comprises a wire feeding hole (31) formed in the upper cover (11), a heating hole (32) formed in the connecting body (15) and a dripping hole (33) formed in the lower cover (12).

3. The high temperature molten metal droplet nozzle (10) according to claim 2, characterized in that: The connecting body (15) includes an upper guide column (151) and a bottom plate (152) connected up and down, the bottom plate (152) constitutes the induction heating part, the heating hole (32) includes an upper hole (321) formed on the upper guide column (151) and a lower hole (322) formed on the bottom plate (152), and the nozzle (2) is arranged at the connection between the upper hole (321) and the lower hole (322).

4. The high-temperature molten metal droplet nozzle (10) according to claim 3, characterized in that: The peripheral wall of the nozzle (2) is provided with an annular rib (22), and the connection between the upper hole (321) and the lower hole (322) is provided with an annular groove (153) embedded and matched with the annular rib (22).

5. The high temperature molten metal droplet nozzle (10) according to claim 3, characterized in that: The material of the upper cover (11), the lower cover (12) and the upper guide column (151) includes quartz, the material of the connecting bolt (13) and the connecting nut (14) includes ceramic, the material of the bottom plate (152) includes graphite, and the material of the nozzle (2) includes tungsten carbide.

6. The high temperature molten metal droplet nozzle (10) according to claim 3, characterized in that: The lower end of the nozzle (2) extends into the dripping hole (33), and the diameter of the lower hole (322) is smaller than the diameter of the dripping hole (33).

7. The high temperature molten metal droplet nozzle (10) according to claim 1, characterized in that: The material of the high-temperature molten metal droplet nozzle (10) is a high-temperature resistant material.

8. A high-temperature metal molten droplet 3D printer (100), characterized in that: The printer comprises a frame (20), a printing platform (30), a wire feeder (40), an induction heater (50) and a high-temperature molten metal droplet nozzle (10) as described in any one of claims 1 to 7, wherein the printing platform (30) is arranged on the frame (20), the wire feeder (40) is arranged on the frame (20) and is located above the printing platform (30), the induction heater (50) is arranged on the frame (20), and the induction heating coil (501) of the induction heater (50) extends between the printing platform (30) and the wire feeder (40), the induction heating coil (501) is arranged in a ring shape, and its axial direction extends in the up and down direction, and the high-temperature molten metal droplet nozzle (10) is penetrated by the induction heating coil (501).

9. The high-temperature molten metal droplet 3D printer (100) according to claim 8, characterized in that: The height of the induction heating part of the high-temperature molten metal droplet nozzle (10) relative to the printing platform (30) is equal to the height of the induction heating coil (501) relative to the printing platform (30).

10. The high temperature molten metal droplet 3D printer (100) according to claim 8, characterized in that: The printer further comprises a platform heater (60); the frame (20) has an up-down direction, a first horizontal direction and a second horizontal direction perpendicular to each other; the printing platform (30) is used to move relative to the frame (20) along the up-down direction, the first horizontal direction and the second horizontal direction; the platform heater (60) is arranged inside the printing platform (30) and is used to heat the printing platform (30); the high-temperature molten metal droplet nozzle (10) is arranged above the printing platform (30); the wire feeder (40) is arranged above the high-temperature molten metal droplet nozzle (10) and is used to feed metal wire into the wire feeding channel (3) of the high-temperature molten metal droplet nozzle (10); and the induction heater (50) is used to induction heat the metal wire in the wire feeding channel (3).

11. The high temperature molten metal droplet 3D printer (100) according to claim 10, characterized in that: The printer further comprises a three-dimensional motion platform (70), wherein the three-dimensional motion platform (70) comprises a lifting frame (701) and a two-dimensional motion platform (702), wherein the lifting frame (701) is mounted on the frame (20), and the two-dimensional motion platform (702) is mounted on the upper end of the lifting frame (701), and the printing platform (30) is arranged on the upper end of the two-dimensional motion platform (702), and the printing platform (30) is movably mounted on the frame (20) along the up-down direction, the first horizontal direction, and the second horizontal direction via the three-dimensional motion platform (70).

12. The high temperature molten metal droplet 3D printer (100) according to claim 10, characterized in that: The printing platform (30) comprises a base (301) and a platform body (302); a support column (3011) is arranged at the upper end of the base (301); and the platform body (302) is arranged at the upper end of the support column (3011).

13. The high temperature molten metal droplet 3D printer (100) according to claim 12, characterized in that: The platform body (302) comprises a bottom shell (3021) and a printing platform plate (3022); the bottom shell (3021) is arranged at the upper end of the support column (3011) and has an upwardly open mounting cavity (30211); the printing platform plate (3022) is covered at the opening of the mounting cavity (30211); the platform heater (60) is arranged inside the mounting cavity (30211) and is connected to the printing platform plate (3022).

14. The high temperature molten metal droplet 3D printer (100) according to claim 13, characterized in that: The printer further comprises a platform radiator (80), wherein the platform radiator (80) is arranged between the base (301) and the platform body (302).

15. The high temperature molten metal droplet 3D printer (100) according to claim 13, characterized in that: The printing platform plate (3022) is made of a high temperature resistant material.

16. The high temperature molten metal droplet 3D printer (100) according to claim 13, characterized in that: The printer also includes a platform thermometer, which is arranged inside the installation cavity (30211) and is used to detect the temperature of the printing platform plate (3022).

17. The high temperature molten metal droplet 3D printer (100) according to claim 10, characterized in that: Two mounting rods (201) are mounted on the frame (20), the two mounting rods (201) are located above the printing platform (30) and are spaced apart along the second horizontal direction, and the high-temperature molten metal droplet nozzle (10) is sandwiched between the two mounting rods (201).

18. A control method for a high-temperature molten metal droplet 3D printer, based on the high-temperature molten metal droplet 3D printer according to any one of claims 8 to 17, characterized in that: The control method includes: Inductively heating the induction heating portion by means of an induction heater (50) to transfer heat to the nozzle (2); Feeding a metal wire into a wire feeding channel (3) of a nozzle body (1) through a wire feeder (40) until the wire extends into a drip hole (21) of the nozzle (2), so that the metal wire contacts the nozzle (2) and is heated; When the head of the metal wire in the drip hole (21) is melted, the metal wire is fed downwardly by the wire feeder (40) until a molten droplet is formed at the lower end of the drip hole (21); The metal wire is retracted upwards by the wire feeder (40) until the molten liquid droplets drip from the lower end of the drip hole (21).

19. The control method of the high temperature molten metal droplet 3D printer according to claim 18, characterized in that: Before the metal wire is fed into the wire feeding channel (3) of the nozzle body (1) by the wire feeder (40) until it extends into the drip hole (21) of the nozzle (2) so that the metal wire contacts the nozzle (2) and is heated, the control method further comprises: heating the printing platform (30) to a preset temperature.

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