This application generally refers to printing heads used in wire-based additive manufacturing. More specifically, this application relates to printing heads that can produce a high-pressure laminar flow of shielding gas.
Additive manufacturing is a process by which a product or part is manufactured by adding one layer of material on top of another in a sequence or pattern that results in a solid part being built. This method of manufacturing is referred to as three dimensional or 3-D printing and can be done with different materials, including plastic and metal.
Wire-based 3-D printing of metallic structures can involve using an energy source to create a weld pool, and feeding a metal wire (feed material) into the weld pool by way of a printing head or printing head nozzle. Energy is used to create the weld pool. Some systems use electricity and others use lasers for the energy. Electric systems typically pass an electric current through the feed wire into the weld pool. The printing head, and subsequently the weld pool can be moved. As the printing head and the weld pool moves, the trailing edge of the pool cools and solidifies. Through this process of gradually moving the printing head along a path, and depositing one layer on a previous layer, a fully printed part is formed.
The process by which material is deposited can be controlled by the use of shielding gas around the feed material. The shielding gas can protect the weld pool from corrosive gases and moisture.
Systems and methods in accordance with some embodiments of the invention are directed to a printing head that is configured to produce concentric flows of shielding gas around a feed material for manufacturing metallic parts.
One embodiment of the invention includes a printing nozzle comprising: a main cylindrical body forming a first fluid flow channel extending a length of the body from a proximal end and a distal end and configured to receive a first fluid; and a second cylindrical body forming a second fluid flow channel concentrically located exterior to the first fluid flow channel, and the second fluid flow channel extends a length of the body from a proximal end and a distal end and configured to receive a second fluid and direct the second fluid surrounding the first fluid flow; where the proximal end of the main cylindrical body is adjacent to the proximal end of the second cylindrical body; and where the distal end of the main cylindrical body aligns with the distal end of the second cylindrical body.
Another embodiment further comprises a plurality of diffuser holes circumferentially disposed on the main cylindrical body wherein each of the plurality of diffuser holes connects the second fluid flow channel to an exterior surface of the main cylindrical body.
An additional embodiment further comprises an external housing, wherein the external housing cooperatively engages with the exterior surface of the main cylindrical body and forms a seal therebetween, the external housing has an external housing wall that sits away from the exterior surface of the main cylindrical body and forms a chamber therebetween, wherein the external housing is aligned with the main cylindrical body such that the chamber covers each of the plurality of diffuser holes, and wherein the external housing has a fluid inlet configured to receive a fluid and transmit the fluid into the chamber such that the fluid can then be transferred to the second fluid channel by way of the plurality of diffuser holes.
In a further embodiment, the fluid inlet has an exterior surface that extends to a top surface of the external housing.
In another further embodiment, the fluid inlet has an elongated body that extends outward from the external housing and is perpendicular to the housing with an opening that connects the chamber to a fluid supply system.
In yet another embodiment, the second fluid flow channel is configured to maintain the second fluid at a pressure greater than or equal to a pressure of the first fluid.
In a yet further embodiment, the second fluid flow channel comprises a diffuser comprising a plurality of holes, wherein the diffuser is configured to reduce a velocity of the second fluid.
In another embodiment again, the nozzle is configured to connect with a wire arc additive manufacturing printer.
In yet another embodiment, the first fluid is selected from the group consisting of: carbon dioxide, argon, helium, nitrogen, neon, xenon, oxygen, and any combinations thereof; wherein the second fluid is selected from the group consisting of: carbon dioxide, argon, helium, nitrogen, neon, xenon, oxygen, and any combinations thereof.
In a further embodiment again, the nozzle comprises a metallic material selected from the group consisting of: a Ni-based alloy, a Ni-based superalloy, a Ni—Cr based alloy, a Cu-based alloy, a Cu—Ni-based alloy, a Cu—Cr—Nb alloy, a Cu—Co—Nb-based alloy, a ferrous alloy, an iron-based alloy, a Co—Cr-based alloys, a Ti-based alloy, and a steel.
Another embodiment includes a printing nozzle comprising: a main cylindrical body having a first end having a first diameter and a second end having a second diameter that is smaller than the first diameter, wherein the main cylindrical body has a wall with an outer surface and an inner surface, wherein the wall extends a longitudinal length of the main cylindrical body between the first and second end; a second cylindrical body having a first end having a first diameter and a second end having a second diameter that is smaller than the first diameter, wherein the second cylindrical body has a wall with an outer surface and an inner surface, wherein the wall extends a longitudinal length of the second cylindrical body between the first and second end, wherein the second cylindrical body concentrically located exterior to the main cylindrical body; wherein the first end of the second cylindrical body is adjacent to the first end of the main cylindrical body; wherein the inner surface of the main cylindrical body forms a first fluid flow channel configured to receive a first fluid; the outer surface of the main cylindrical body and the inner surface of the second cylindrical body forms a second fluid flow channel configured to receive a second fluid; a plurality of diffuser holes circumferentially disposed on the wall of the main cylindrical body such that each of the plurality of diffuser holes transcends through the wall connecting the second fluid channel with the outer surface of the main cylindrical body.
A further embodiment comprises an external housing, wherein the external housing cooperatively engages with the outer surface of the main cylindrical body and forms a seal therebetween, wherein the external housing has an external housing wall that sits away from the outer surface of the main cylindrical body and forms a chamber therebetween, wherein the external housing is aligned with the main cylindrical body such that the chamber covers each of the plurality of diffuser holes, and wherein the external housing has a fluid inlet configured to receive the second fluid and transmit the second fluid into the chamber such that the second fluid can then be transferred to the second fluid channel by way of the plurality of diffuser holes.
In another embodiment, the fluid inlet has an exterior surface that extends to a top surface of the external housing.
In yet another embodiment, the fluid inlet has an elongated body that extends outward from the external housing and is perpendicular to the housing with an opening that connects the chamber to a fluid supply system.
In an additional embodiment, the second fluid flow channel is configured to maintain the second fluid at a pressure greater than or equal to a pressure of the first fluid.
In another yet embodiment, the second fluid flow channel comprises a diffuser comprising a plurality of holes, wherein the diffuser is configured to reduce a velocity of the second fluid.
In yet another further embodiment, the nozzle is configured to connect with a wire arc additive manufacturing printer.
In a further yet embodiment, the first fluid is selected from the group consisting of: carbon dioxide, argon, helium, nitrogen, neon, xenon, oxygen, and any combinations thereof; wherein the second fluid is selected from the group consisting of: carbon dioxide, argon, helium, nitrogen, neon, xenon, oxygen, and any combinations thereof.
In an additional embodiment again, the nozzle comprises a metallic material selected from the group consisting of: a Ni-based alloy, a Ni-based superalloy, a Ni—Cr based alloy, a Cu-based alloy, a Cu—Ni-based alloy, a Cu—Cr—Nb alloy, a Cu—Co—Nb-based alloy, a ferrous alloy, an iron-based alloy, a Co—Cr-based alloys, a Ti-based alloy, and a steel.
Another further embodiment includes a printing nozzle comprising: a main cylindrical body wherein the main cylindrical body has a first fluid flow channel extending a length of the body from a proximal end and a distal end and configured to receive a first fluid; and a second fluid flow channel concentrically located exterior to the first fluid flow channel and within the main cylindrical body and configured to receive a second fluid and direct the second fluid such that, when the printing nozzle is in use, the second fluid surrounds the first fluid flow and controls the turbulence of the first fluid flow, wherein the second fluid flow channel is configured to maintain the second fluid at a higher pressure than the first fluid.
An additional embodiment further comprises a plurality of diffuser holes circumferentially disposed about the main cylindrical body wherein each of the plurality of diffuser holes connects the second fluid flow channel to an exterior surface of the main cylindrical body.
Yet another embodiment further comprises an external housing, wherein the external housing cooperatively engages with the exterior surface of the main cylindrical body and forms a seal therebetween, the external housing has an external housing wall that sits away from the exterior surface of the main cylindrical body and forms a chamber therebetween, wherein the external housing is aligned with the main cylindrical body such that the chamber covers each of the plurality of diffuser holes, and wherein the external housing has a fluid inlet configured to receive a fluid and transmit the fluid into the chamber such that the fluid can then be transferred to each of the plurality of channels by way of the plurality of diffuser holes.
In a further embodiment again, the fluid inlet has an exterior surface that extends to a top surface of the external housing.
In another further embodiment, the fluid inlet has an elongated body that extends outward from the external housing and is perpendicular to the housing with an opening that connects the chamber to a fluid supply system.
An additional embodiment includes a high-pressure printing nozzle comprising: a main cylindrical body having a first end having a first diameter and a second end having a second diameter that is smaller than the first diameter, wherein the main cylindrical body has an outer wall with an outer surface and an inner surface, wherein the outer wall extends a longitudinal length of the main cylindrical body between the first and second end; an inner wall of the main cylindrical body connected to the outer wall at an upper surface and concentrically disposed within the main cylindrical body separated from the outer wall by a predetermined distance away from the inner surface of the outer wall thereby forming a space therebetween, wherein the inner wall extends along the longitudinal length of the outer wall to a first setback point away from the second end and within the main cylindrical body forming a high-pressure exit; a plurality of support structures concentrically disposed within the space between the outer wall and the inner wall and extending longitudinally along the length of the inner wall to a second setback point away from the high-pressure exit forming a plurality of channels in the space between the outer wall and the inner wall; and a plurality of diffuser holes concentrically disposed within the outer wall of the main cylindrical body such that each of the plurality of diffuser holes extends from the outer surface to the inner surface connecting each of the plurality of channels with an exterior portion of the main cylindrical body, wherein each of the plurality of diffuser holes are configured to receive a high pressure fluid, transmit said high-pressure fluid into the space between the outer wall and the inner wall, and forming a high-pressure fluid at the high-pressure exit.
Another embodiment further comprises an external housing, wherein the external housing cooperatively engages with the exterior surface of the main cylindrical body and forms a seal therebetween, wherein the external housing has an external housing wall that sits away from the exterior surface of the main cylindrical body and forms a chamber therebetween, wherein the external housing is aligned with the main cylindrical body such that the chamber covers each of the plurality of diffuser holes, and wherein the external housing has a fluid inlet configured to receive a fluid and transmit the fluid into the chamber such that the fluid can then be transferred to each of the plurality of channels by way of the plurality of diffuser holes.
Another further embodiment includes a printing nozzle comprising: a main cylindrical body wherein the main cylindrical body has a first fluid flow channel extending a length of the body from a proximal end and a distal end and configured to receive a first fluid; and a second fluid flow channel concentrically located exterior to the first fluid flow channel and within the main cylindrical body and configured to receive a second fluid and direct the second fluid such that the second fluid flow channel is configured to maintain the second fluid at a higher pressure than the first fluid.
An additional embodiment comprises a third fluid flow channel concentrically located exterior to the second fluid flow and configured to receive a third fluid and direct the third fluid such that, when the printing nozzle is in use, the third fluid surrounds the second fluid flows and controls the turbulence of the first fluid flow, wherein the third fluid flow channel is configured to maintain the third fluid at a similar pressure as the first fluid.
Another further embodiment comprises a plurality of diffuser holes circumferentially disposed about the main cylindrical body wherein each of the plurality of diffuser holes connects the second fluid flow channel to an exterior surface of the main cylindrical body.
An additional further embodiment comprises an external housing, wherein the external housing cooperatively engages with the exterior surface of the main cylindrical body and forms a seal therebetween, the external housing has an external housing wall that sits away from the exterior surface of the main cylindrical body and forms a chamber therebetween, wherein the external housing is aligned with the main cylindrical body such that the chamber covers each of the plurality of diffuser holes, and wherein the external housing has a fluid inlet configured to receive a fluid and transmit the fluid into the chamber such that the fluid can then be transferred to each of the plurality of channels by way of the plurality of diffuser holes.
In a further yet embodiment, the fluid inlet has an exterior surface that extends to a top surface of the external housing.
In yet another embodiment, the fluid inlet has an elongated body that extends outward from the external housing and is perpendicular to the housing with an opening that connects the chamber to a fluid supply system.
Yet another embodiment includes a high-pressure printing nozzle comprising: a first cylindrical body having a first end having a first diameter and a second end having a second diameter that is smaller than the first diameter, wherein the first cylindrical body has an outer wall with an outer surface and an inner surface, wherein the outer wall extends a longitudinal length of the first cylindrical body between the first and second end; an inner wall of the first cylindrical body connected to the outer wall at an upper surface and concentrically disposed within the first cylindrical body separated from the outer wall by a predetermined distance away from the inner surface of the outer wall thereby forming a space therebetween, wherein the inner wall extends along the longitudinal length of the outer wall to a first setback point away from the second end and within the first cylindrical body forming a high-pressure exit; a second cylindrical body having a first end having a first diameter and a second end having a second diameter that is smaller than the first diameter, wherein the second cylindrical body has an outer wall with an outer surface and an inner surface, wherein the outer wall extends a longitudinal length of the second cylindrical body between the first and second end, wherein the first and second diameters of the second cylindrical body are greater than the first and second diameters of the first cylindrical body; wherein the first cylindrical body and the second cylindrical body are concentrically located; an inner wall of the second cylindrical body connected to the outer wall at an upper surface and concentrically disposed within the second cylindrical body separated from the outer wall by a predetermined distance away from the inner surface of the outer wall thereby forming a space therebetween, wherein the inner wall extends along the longitudinal length of the outer wall to a second setback point away from the second end and within the second cylindrical body forming a second high-pressure exit; a plurality of support structures concentrically disposed within the space between the outer wall and the inner wall and extending longitudinally along the length of the inner wall to a second setback point away from the high-pressure exit forming a plurality of channels in the space between the outer wall and the inner wall; and a plurality of diffuser holes concentrically disposed within the outer wall of the main cylindrical body such that each of the plurality of diffuser holes extends from the outer surface to the inner surface connecting each of the plurality of channels with an exterior portion of the main cylindrical body, wherein each of the plurality of diffuser holes are configured to receive a high pressure fluid, transmit said high-pressure fluid into the space between the outer wall and the inner wall, and forming a high-pressure fluid at the high-pressure exit.
Another further embodiment comprises an external housing, wherein the external housing cooperatively engages with the exterior surface of the first cylindrical body and forms a seal therebetween, wherein the external housing has an external housing wall that sits away from the exterior surface of the first cylindrical body and forms a chamber therebetween, wherein the external housing is aligned with the first cylindrical body such that the chamber covers each of the plurality of diffuser holes, and wherein the external housing has a fluid inlet configured to receive a fluid and transmit the fluid into the chamber such that the fluid can then be transferred to each of the plurality of channels by way of the plurality of diffuser holes.
Additional embodiments and features are set forth in part in the description that follows, and in part will become apparent to those skilled in the art upon examination of the specification or may be learned by the practice of the disclosure. A further understanding of the nature and advantages of the present disclosure may be realized by reference to the remaining portions of the specification and the drawings, which forms a part of this disclosure.
The description will be more fully understood with reference to the following figures. Embodiments of the invention in these figures and should not be construed as a complete recitation of the scope of the invention.
Systems and methods for producing a laminar flow of shielding gas are illustrated in the description herein. Spatter produced during the deposition process can clog the nozzle and significantly affect gas flow and coverage resulting in poor deposition and ultimately poor material properties. The printing head in accordance with many embodiments can provide adequate gas coverage and prevent spatter build-up from deposition in order to increase continuous run time. Some embodiments described herein provide an added advantage of reducing the cleaning time for cleaning material build up around the nozzle tip which can reduce costs associated with producing complex metal parts with additive manufacturing.
Several embodiments include print heads with (but not limited to) improved nozzles to provide uniform gas coverage and/or prevent spatter build-up during the printing process. The improvements of the nozzles in accordance with many embodiments can be applied to wire-based additive manufacturing and/or wire arc additive manufacturing in vertical orientations and/or in horizontal orientations. Examples of improvement include (but are not limited to) coating the nozzle, incorporating blowout functions, positioning the nozzle further from the contact tip, and any combinations thereof. The nozzles in accordance with certain embodiments can be made of materials including (but not limited to): metals, metal alloys, copper-based alloys, plastics, ceramics, and any combinations thereof. In many embodiments, high temperature refractory ceramic coatings can be applied to the nozzles for casting release and/or casting repairs. Ceramic coatings in accordance with some embodiments can be non-wetting to the molten print material including (but not limited to) metals, metal alloys, aluminum, aluminum-based alloys. Examples of coating materials include (but are not limited to) boron nitride, carbon, and graphite.
Many embodiments incorporate blowout functions by adding internal channels (also referred as internal high-pressure channels) to the nozzle to increase the velocity of gas flow. In some embodiments, the internal channels can have smaller cross-section area compared to the central channels for the feed material in order to generate high velocity gas flow. Higher gas flow velocity can perform blow-out functions and prevent spatter build-up. In some embodiments, high velocity gas flow in the internal channels enables blow out functions of the nozzle. The blow out functions can clear up material buildup at the contact tip of the nozzle. The high velocity gas flow can run intermittently. In a number of embodiments, the high velocity gas flow can be used to clean up material buildup when the print head is not printing. Several embodiments are directed to a nozzle for a metallic additive manufacturing head that is configured with concentric and separate fluid flow channels for directing the flow of a shielding gas around a feed material. Embodiments have an internal channel that extends from an upper closed end near the proximal end of the nozzle that interfaces with the printing device. The internal channel extends along the length of the nozzle and runs parallel to a main central channel to an opening near the opening of the nozzle at the distal end of the body. The internal channel can be supported by one or more support fixtures that traverse the width of the channel and connect the exterior wall of the nozzle with an interior wall. In embodiments the internal channel is connected to the external surface of the external wall of the nozzle by one or more different holes. These holes can serve to direct the flow of a high-pressure gas into the internal channel.
In several embodiments, the opening of the internal channels at the distal end of the body can locate at a distance from the opening of the main central channel. The distance in accordance with some embodiments can be from about 1 mm to about 15 mm; or about 2 mm; or about 5 mm; or about 8 mm; or about 12 mm; or greater than about 15 mm; or less than about 1 mm.
In many embodiments, the nozzles can be positioned further back relative to the contact tip face to reduce the amount of spatter that can reach the nozzle. Conventionally, the nozzle extends about 2 mm from the contact tip face. Several embodiments move the nozzle further back to be less than about 2 mm from the contact tip face. In certain embodiments, the nozzle can be positioned behind the contact tip face. The inventors realized that there are several challenges with moving the nozzle back from the contact tip face. One challenge can be gas coverage. Because the laminar section of flow is much smaller compared to the turbulent flow, moving the nozzle back even a few millimeters may significantly change where the laminar to turbulent flow transition happens. If the transition to laminar flow happens too far above the weld bead, it can introduce air leading to an unstable arc and result in poor material properties. A second challenge can be that the density of argon is higher than the density of air. For additive manufacturing, the argon coming out of the nozzle sinks due to the higher density, which may result in a gas flow profile that is slightly arced down. The further away from the print part, the lower gas flow profile from the weld bead it may become. A number of embodiments address the challenge of sinking gas flow by increasing gas flow coverage and/or velocity. Higher gas flow velocity and/or higher gas coverage of the nozzle can minimize the effect of gas sinking due to positioning the nozzle further back relative to the contact tip. In some embodiments, a secondary cup can be added to nozzles to increase gas coverage.
Nozzles in accordance with a number of embodiments have a distance between the open end of the high-pressure channel and the open end of the central channel. The distance can vary from about 2 mm to about 15 mm; or about 2 mm; or about 6 mm; or about 8 mm; or about 10 mm; or less than about 2 mm; or greater than about 10 mm. Several embodiments cut back the nozzle by shifting the thread location relative to the rest of the nozzle. Many embodiments keep the same thread counts and/or thread geometries when the thread location is shifted.
Embodiments are also configured with high-pressure housings that engage with the external wall of the nozzle. The high-pressure housing has an inlet that receives a shielding gas. The shielding gas passes through the inlet into a pressure chamber. The pressure chamber is formed between an internal wall of the housing and the external wall of the nozzle. The pressure chamber is configured to engage with or cover each of the holes (also referred to in this description as diffuser holes) that run through the external wall of the nozzle such that gas can flow from the chamber into the internal channel of the nozzle. The pressure chamber can be embodied as, what this specification terms wall diffusers, which evenly distribute gas concentrically to get a more uniform flow. In some embodiments, the diffuser holes of the pressure chamber of the internal high-pressure channels can be on the same cross section plane or on the different cross section plane as the inlets. As gas is fed into the chamber through the inlet, pressure can build up, because the gas will not immediately enter the internal nozzle channel. Additionally, as pressure builds, the flow of the gas into the internal channel increases in speed due to the constricted diameter of the internal channel. Accordingly, the high pressure and high velocity of gas helps to stabilize or reduce the turbulent flow of the gas moving through the main channel of the nozzle. In addition, the flow of the high-pressure gas can be regulated. In other words, the flow does not have to be consistent nor does the flow have to be maintained throughout the process of building a part. For example, embodiments can utilize the high-pressure flow channel to direct bursts of higher-pressure gas through the nozzle. The higher-pressure bursts can be used to remove any buildup of material around the print head and more specifically the tip of the nozzle. This can be advantageous to allow for shorter down times in printing and keep the part temperature consistent throughout the build.
Several embodiments implement a secondary cup (also referred as an outer cup and/or a secondary cylinder) in the nozzle to increase shielding gas coverage. The cylinder that forms the central channel can be referred as an inner cup and/or a first cylinder. An outer channel can be formed by the space between the first cylinder and the second cylinder. Additional shielding gas can be flown in the outer channel to increase shielding gas coverage.
The secondary cup in accordance with some embodiments can have a shape of concentric or coaxial cylinder. In a number of embodiments, the internal high-pressure inlet cylinder and the central channel cylinder can be positioned within the inner diameter of the secondary cylinder. The cylinders of the central channel, the internal high-pressure channel, and the secondary cylinder are concentrically aligned. The gas flow in the secondary cup can have a pressure of less than about 15 psi; or from about 15 psi to about 20 psi; or greater than about 20 psi; or from about 20 psi to about 30 psi; or greater than about 30 psi; or greater than about 50 psi; or greater than about 100 psi. In certain embodiments, the secondary cup can have a lower gas velocity compared to the gas velocity in the internal high-pressure channel. In several embodiments, the secondary cup can have a gas flow velocity greater than or equal to the gas velocity in the central channel. In some embodiments, the secondary cup can have a similar gas flow velocity compare to the gas flow velocity in the central channel. In a number of embodiments, the gas flow in the secondary cup and the gas flow in the central channel can run continuously to provide gas coverage for the nozzle during printing. In many embodiments, the gas flow velocity in various channels can be kept the same and/or different. The gas flow in the secondary cup can be kept at a different flow rate compare to the gas flow rate in the central channel in order to keep the same gas flow velocities in the two channels in accordance with certain embodiments. In some embodiments, a higher pressure (such as pressure higher than about 1000 psi) can be used to remove any build up on the secondary cup. In certain embodiments, the gas flow in the secondary cup can be controlled turbulent flow. Some embodiments control the turbulent flow by controlling the mixing length of flow, and/or how far air can mix into the flow.
In many embodiments, the secondary cups are configured with pressure housings and/or high-pressure housings that engage with the external wall of the nozzle. The pressure housing has inlets that receive shielding gases. Shielding gases pass through the inlets into a secondary cup pressure chamber. The secondary cup pressure chambers can be embodied as what this specification calls wall diffusers. The secondary cup pressure chamber is configured to engage with or cover each of the holes (diffuser holes) that run through the external wall of the nozzle such that gas can flow from the chamber into the outer channel of the secondary cup of the nozzle. The pressure chambers enable even distribution of gas concentrically to get a more uniform flow. The diffuser holes of the secondary cup can be on the same plane or on the different plane as the inlets in accordance with some embodiments. In certain embodiments, the diffuser holes are on a plane that is different from the inlets such that the diffuser holes can diffuse the gas better.
In several embodiments, nozzles can have at least one high-pressure housing to introduce shielding gases. Inlets and the pressure chambers can be arranged in various locations on nozzles to adapt to different types of torch configurations. In certain embodiments, nozzles can have two inlets that are about 180 degrees apart from each other.
In many embodiments, nozzles can have a cylindrical shape with a circular cross section. In certain embodiments, nozzles and/or nozzle assemblies can have a central channel that has a shape of concentric or coaxial cylinder. Nozzles and/or nozzle assemblies in accordance with some embodiments can have internal high-pressure channels that have a shape of concentric or coaxial cylinder. In such embodiments, the internal high-pressure channel can be formed by an internal cylinder and the central channel cylinder can be positioned within the inner diameter of the internal cylinder. Internal cylinders can be referred as internal cups and/or internal channel cylinders. Central channel cylinders can be referred as first cylinders and/or inner cups. The internal cup surrounds the inner cup such that the cylinders of the central channel and the internal high-pressure cylinder are concentrically aligned. This helps to ensure that the high-pressure shielding gas completely surrounds the lower pressure shielding gas that would be passed through the main central channel of the nozzle and/or nozzle assembly.
The first cylinder can be positioned within the inner diameter of the second cylinder. The first and the second cylinders are concentrically aligned such that the shielding gas from the outer channel of the secondary cup can provide coverage for the main central channel. Secondary cups can be referred as second cylinders and/or outer cups. The secondary cup helps to expand the shielding gas coverage around the molten materials during additive manufacturing processes. In several embodiments, the internal high-pressure channels allow gas flow at different flow rates between the inner and outer channels.
In some embodiments, the inner cup can have a diameter from about 15 mm to about 20 mm; or less than about 15 mm; or greater than about 20 mm. In certain embodiment, the outer cup can have a diameter from about 27 mm to about 35 mm; or less than about 27 mm; or greater than about 35 mm. The outer cup has a diameter that is larger than the inner cup. The outer cup can have an angle formed between the vertical wall and the slant wall of the outer cup. The angle can range from about 160 degrees to about 170 degrees; or less than about 160 degrees; or greater than about 170 degrees.
Many embodiments include diffusers in the nozzle to reduce the velocity of gas and reduce turbulence in the body of the secondary cup before exiting the nozzle. The diffusers can be placed in the secondary cup. Diffusers in the secondary cup are different from the wall diffusers and/or the pressure chambers. Diffusers in accordance with various embodiments can have different configurations and include various numbers of rings. Each ring comprises a plurality of holes. In several embodiments, the cross-sectional area of the diffuser rings can be increased to reduce the gas velocity. Higher number of the diffuser rings and/or smaller size holes in the diffuser rings can increase the cross-sectional area. Examples of different configurations of diffusers can include (but are not limited to): 2-ring diffuser, 3-ring diffuser, 4-ring diffuser, 5-ring diffuser, 6-ring diffuser. Examples of the average diameter of holes on diffuser rings include (but are not limited to) about 1.5 mm; or less than about 1.5 mm; or greater than about 1.5 mm.
In several embodiments, the nozzle can have a conical shape. The angle of the cone of the nozzle can vary from about 15 degrees to about 20 degrees. In some embodiments, the nozzle can have a smooth contour to enhance the laminar flow.
As can be appreciated, shielding gases can be any suitable gas for the process. Examples of shielding gases include (but are not limited to) carbon dioxide, argon, helium, nitrogen, neon, xenon, oxygen, and any combinations thereof. Accordingly, in various embodiments, the central channels, the outer channels, and the high-pressure channels can use the same or different shielding gasses. In certain embodiments, the central channels and the outer channels can use the same or different shielding gasses.
Various nozzles in accordance with embodiments can be produced via additive manufacturing, printing, 3D printing, and/or powder-based printing. Examples of additive manufacturing processes for manufacturing nozzles include (but are not limited to) powder bed fusion (PBF), laser powder bed fusion (L-PBF), laser powder bed (LPB), direct metal laser melting (DMLM), direct metal laser sintering (DMLS), selective laser sintering (SLS), selective heat sintering (SHS), laser metal fusion (LMF), laser metal deposition (LMD), selective laser melting (SLM), laser powder directed energy deposition (LP-DED), cold spray additive manufacturing (CSAM), electron beam melting (EBM), direct metal deposition (DMD), binder jetting (BJ), and multi jet fusion (MJF).
In some embodiments, nozzles and/or parts of nozzles can be fabricated using machining. The inner cups and/or outer cups can be fabricated via machining into at least 2 pieces; or at least 3 pieces; or at least 4 pieces. The plurality of pieces can be joined and/or assembled together using screws, fasteners, straps, clamps, and/or adhesives, or using processes such as (but not limited to) machining.
Post manufacturing treatment including (but not limited to) machining and/or heat treatment can be applied to nozzles in order to achieve desired geometries, surface finishes, and/or mechanical properties.
In many embodiments, materials such as (but not limited to) metallic materials, polymeric materials, plastic materials, and/or ceramic materials, can be used for manufacturing inner cups, outer cups, and/or diffusers of nozzles. Various materials can be chosen based on a number of properties: high thermal conductivity; non-wetting characteristics; non-reactive with depositing materials; higher melting point than depositing materials; non-cracking during printing; sturdy, durable, and reusable. Examples of metallic materials include (but are not limited to) nickel (Ni)-based alloys, Ni-based superalloys, Ni-chromium (Cr) based alloys, copper (Cu)-based alloys, Cu—Ni-based alloys, Cu—Cr-niobium (Nb) alloys, Cu-cobalt (Co)—Nb-based alloys, ferrous alloys, iron-based alloys, Co—Cr-based alloys, titanium (Ti)-based alloys, and steel. Ni-based alloys can have high strength. Examples of Ni-based alloys include (but not limited to) Inconel® alloys (such as Inconel®-625 and/or Inconel®-718), and/or Haynes® alloys (such as Haynes®-230). Cu—Co—Nb-based alloys can have high thermal conductivity. Examples of Cu—Co—Nb-based alloys include (but are not limited to) GRCop class alloys, GRCop-42, GRCop-84, C-18150, and C-18200. Examples of steel include (but are not limited to) tool steel, stainless steel, 316L, 17-4PH, low and/or medium carbon steel. Several embodiments use Cu-based alloys for printing nozzles and/or inner cups of nozzles. Some embodiments use steel for printing and/or machining outer cups of nozzles. Examples of polymeric materials and/or plastic materials include (but are not limited to) acrylonitrile butadiene styrene (ABS), polylactic acid (PLA), nylon, thermoplastic polyurethane (TPU), polyvinyl alcohol (PVA), high impact polystyrene (HIPS), composites, carbon fibers, Kevlar, fiberglass, resins, and any combinations thereof. Examples of ceramic materials include (but are not limited to) clay, porcelain, and any combinations thereof.
The inner cup and/or outer cup of the nozzle can be printed in an integral piece and/or separated pieces. Separated pieces of nozzles can be assembled after printing. In several embodiments, inner cup can be printed as an integral piece. In some embodiments, inner cup with various types of diffusers can be printed as an integral piece. In certain embodiments, outer cup can be printed as an integral piece. In some embodiments, outer cup can be printed in two pieces. Two-piece outer cup can be assembled around the inner cup and secured using screws, fasteners, straps, clamps, and/or adhesives, or using processes such as (but not limited to) machining.
Although various embodiments of the nozzle and/or nozzle assembly illustrate a concentrically connected high-pressure chamber, it should be understood that the chamber is merely representative of an embodiment and not intended to illustrate the only possible way of introducing a high-pressure flow of gas into the nozzle elements. It should be understood that other embodiments can be configured to introduce a high-pressure gas into the high-pressure channel of the nozzle from another means.
In addition to the advantages of producing a more laminar flow for the shielding gas, embodiments allow for improved processing time for printing. 3-D printing metallic parts can generate excess material that can adhere to and/or clog up the nozzle and nozzle tip. Traditionally, the nozzle would need to be removed or removed from the printing surface to be cleaned. In some instances, the cleaning process can pose unwanted risks to the printed part. For example, when the energy used to generate the molten bead of material is removed, the material and the part begin to cool. This can create unwanted stresses and potential issues with the printed part. Accordingly, embodiments of the high-pressure printing nozzle lend themselves to improved cleaning to allow for a more continuous printing operation. For example, as the tip of the nozzle becomes clogged or dirty the high-pressure channel can be used to generate a blast of high-pressure gas towards the tip. The high-pressure blast blows away excess material and cleans the tip of the printing nozzle. This can take only a few seconds versus minutes or longer of a more traditional cleaning method. Accordingly, the part being manufactured will not be allowed to cool more than a few seconds, allowing the printing process to continue without interruption. The reduction in cooling time allows for a higher quality part to be printed.
Although the various embodiments described herein are generally applicable to 3-D printing of metallic components, it can be appreciated that such embodiments can be applied to a variety of 3-D printing techniques. For example, embodiments can be adapted and used for Wire Arc Additive Manufacturing or WAAM and the various adaptations of WAAM. In accordance with embodiments, the printing nozzles described herein, having multiple flows of shielding gas, can be more conducive to utilizing more than one feed material wire into a printed part which can produce a higher quality printed part.
Many metallic printing devices utilize a traditional welding type nozzle that are simple tube-like structures as illustrated in
The nozzle design, with a tapered tip 102, is selected to increase the flow of shielding gas near the tip to help produce a more laminar flow around the feed material 106 and the molten bead. However, the open edge of the tip tends to create a turbulent flow 114 as the gas 108 exits the nozzle. Turbulent flow is less desirable because it can produce a lower quality weld. Accordingly, some designs have attempted to reduce the amount of turbulent flow at the tip of the nozzle. For example, some nozzles have attempted to improve the laminar flow affect by using discs or screens 120, as illustrated in
In some embodiments, nozzles may contain a high-pressure channel concentrically located with respect to a main central channel.
The internal high-pressure channel 204 can be fed a high-pressure shielding gas through wall diffusers or holes 210 that are circumferentially placed around the nozzle. The wall diffusers 210 can take on any shape or size such they allow for the shielding gas to move into the internal channel 204 of the nozzle 200. In other words, the wall diffusers 210 are through-holes that connect to the high-pressure internal channels.
In some embodiments, the length of the internal channel 204 extends to a location that is distal to the exit tip 203 of the nozzle. The setback position of the internal channel exit 214 can help to control the flow of the shielding gas as it exits the nozzle tip 203 such that the main shielding gas is contained or formed into a laminar flow by surrounding it with a high-pressure flow of shielding gas. As can be appreciated, the position of the high-pressure internal channel tip 214 can be in any desirable location set back from the exit tip 203 of the nozzle such that it encircles and contains the flow of the main or lower-pressure shielding gas. In some embodiments, the setback position can range up to about 1.5 cm from the exit tip 203 of the nozzle. In several embodiments, the inner wall 208 can be connected to the outer wall 201 by one or more support structures 218. The support structure 218 can run the entire length of the high-pressure internal channel 204 or can terminate just prior to the end or exit of the channel 214. This can effectively create multiple high-pressure internal channels 204 within the nozzle 200. As can be appreciated, in some embodiments the support structures 218 can correspond to each of the various wall diffusers or holes 210 in the nozzle, thus creating a larger number of individual channels 204 within the nozzle.
Additionally, nozzle 300 can have one or more different wall diffusers 316 positioned around the nozzle that connect the outer wall to the high-pressure internal channel 306. Although the nozzle 300 illustrates the position of the wall diffusers 316 in a specific location, it should be appreciated that the wall diffusers could be located at any location longitudinally along the length of the nozzle 300. Additionally, embodiments can have one or more configurations of wall diffusers 316 in various sizes and/or shapes or can have one or more circumferential rows of wall diffusers in the nozzle.
As can be appreciated, the wall diffusers described with respect to
The external housing 404 can be a separate element that engages with the nozzle element 402. In embodiments, the housing 404 has an external wall 414 and an internal cavity 416 or space between the inner wall of the housing 418 and the external wall of the nozzle 419 element 402. The space thereby forms a cavity or pressure vessel by which pressure can build up before entering the internal high-pressure channel 406 of the nozzle 402. In certain embodiments, the housing element 404 forms a seal between the internal cavity 416 and the nozzle 402 such that the shielding gas does not escape through the connection seam 420, but rather is forced to enter the high-pressure internal channel 406 through the various wall diffusers 422. In various embodiments, the housing 404 can have an inlet 424 where the high-pressure shielding gas is fed into the pressure cavity 416. The inlet 424 can take on any suitable form and can be configured to connect to any suitable gas supply system. For example, as illustrated in
Although not specifically illustrated in previous
In several embodiments, the nozzle assembly can be manufactured to be a single piece assembly. In other words, the nozzle and the housing can be a made from a single piece of material rather than two separate components.
Similar to the individual components, the inner wall of the housing 510 and the outer wall of the nozzle 508 form a cavity or chamber 514 that can be considered a pressure chamber for which shielding gas can build up pressure to be fed into the nozzle 502. In accordance with numerous embodiments, the shielding gas can be fed into the chamber 514 through an inlet 516. The inlet 516 can extend outwardly from the chamber 514 and be connected to a supply line of shielding gas. Additionally, it should be appreciated that the inlet can take on any desired configuration and/or design such that it is capable of directing the shielding gas into the chamber 514. In some embodiments the inlet 516 can have an upper portion 517 that is parallel to or flush with the top portion of the assembly 500. Such configuration merely represents an embodiment of the inlet design and it should be appreciated that the inlet can take on any suitable configuration.
In accordance with embodiments, the nozzle assembly 500 can have an internal high-pressure channel 518. The internal high-pressure channel 518 can be positioned between an inner wall of the nozzle 520 and the outer wall 508, thereby forming a space or channel that extends from an upper portion of the assembly to a setback point 522 within the main central channel 524 of the nozzle. The position of the setback point 522 is away from exit tip 526 of the nozzle and within the central channel 524 such that high pressure shielding gas traveling down the high-pressure channel 518 will interact with the lower pressure shielding gas in the main central channel 524. This interaction, prior to the lower pressure shielding gas exiting the exit tip 526 helps to ensure a more laminar flow of the lower pressure shielding gas around the feed material 512 and molten bead 513. The distance 519 between the open end of the high-pressure channel 518 and the open end of the central channel 524 is about 12 mm.
In embodiments of the nozzle assembly, the internal high-pressure channel 518 can be connected to the high-pressure chamber 514 through one or more diffuser holes 528. The diffuser holes 528 transect the outer wall of the nozzle and connect the chamber 514 with the internal channel 518. The diffuser holes 528 can be positioned at a location within the chamber 514 that allows for the high-pressure shielding gas to pass from the chamber 514 into the high-pressure channel 518. In some embodiments, the diffuser holes 528 can be positioned between support structure supports 530. As can be appreciated, the support structure supports 530 can maintain the spacing between the inner wall and the outer wall as well as form separate high-pressure channels 518 circumferentially surrounding the main central channel 524. In several embodiments, the diffuser holes 528 may not be aligned in a same plane as the inlets 516, as shown in
As can be fully appreciated, the nozzle assembly and/or nozzle can be configured to connect to a printing head (not shown) in any number of methods. For example, the nozzle assembly 500 illustrated in
Several embodiments select the distance between the open end of the high-pressure channel and the open end of the central channel to remove the spatter accumulated during printing. As shown in
A number of embodiments select the distance between the open end of the high-pressure channel and the open end of the central channel to be between about 2 mm and about 12 mm.
In contrast to a threaded connection, some embodiments can include a slip connection or a nozzle that is a press fit onto the printing head.
As can be appreciated, embodiments of the nozzle and/or nozzle assembly can have a cylindrical shape with a circular cross section. Accordingly, embodiments of the nozzle and/or nozzle assembly can have a concentric or coaxial cylinder where the main cylinder is the outer most cylinder forming the main structure and the secondary cylinder is positioned within the inner diameter of the main cylinder.
Many embodiments implement two cups in nozzles to expand gas coverage. In several embodiments, the nozzles can have at least one pressure chamber for high-pressure internal channels and for outer channels. Each pressure chamber is connected with at least one inlet.
The nozzle assembly 800 has pressure chamber (or wall diffusers) 814 to provide storage and transfer gas to the high-pressure gas channels 818. This can help to increase the amount of gas flow into the inner internal high-pressure channels 818. The cavity or chamber 814 can be a pressure chamber for shielding gas to build up pressure to be fed into the internal high-pressure channels 818. The shielding gas can be fed into the chamber 814 through inlets 816. The inlet 816 can extend outwardly from the chamber 814 and be connected to a supply line of shielding gas. The inlet can take on any desired configuration and/or design such that it is capable of directing the shielding gas into the chamber 814.
In various embodiments, the inner internal high-pressure channels 818 can be connected to the high-pressure chamber or wall diffuser 814 through one or more diffuser holes 828 as shown in
The shielding gas in the inner high-pressure channels 818 and the shielding gas in the outer channels 819 can be flown at the same and/or different flow rate. The ability to have different flow rate in the channels enables better control of spatter build up in the nozzle. The inlets 816 to the chambers 814 can be positioned about 180 degrees apart from each other to provide access to various types of torches. The inlets 826 to the outer chambers 821 can be positioned about 180 degrees apart from each other to provide access to various types of torches. The diameter of the inlets to the inner and outer high-pressure channels can be varied to achieve the desired gas flow. The secondary cylindrical cup that forms the outer channels 819 can have varied diameters to reduce spatter buildup. Examples of the outer cup diameter can vary from about 25 mm to about 35 mm. In some embodiments, the diameter of the secondary cylindrical cup can be changed to modify gas coverage. In certain embodiments, the wall thickness can be changed in order to reduce the weight of the nozzle. In various embodiments, the two-cup nozzle can have a pressure in the high-pressure channels 818 and/or in the outer channels 819 from about 20 psi to about 200 psi; or lower than about 20 psi; or lower than about 30 psi; or higher than about 200 psi. The blowout pressure can be applied to the nozzle at various time intervals.
In many embodiments, two-cup nozzles can have a cylindrical shape with a circular cross section. In some embodiments, the nozzle can have a concentric or coaxial cylinder where the secondary or outer cup is the outer most cylinder forming the secondary channels and the inner cup is positioned within the inner diameter of the outer cup and forms the inner channels.
In several embodiments, diffusers can be added to the outer channels. The diffusers in accordance with some embodiments can modify the gas flow to be less turbulent when exiting the channels. In certain embodiments, the diffuser can include a series of rings in the outer cup. Each ring comprises a plurality of holes. The holes can have an average diameter of about 1.5 mm; or less than about 1.5 mm; or about greater than about 1.5 mm.
In many embodiments, the nozzles can be moved further away from the printed object relative to the contact tip face to reduce the amount of spatter that can reach the nozzle. The nozzle in accordance with a number of embodiments can be a distance back from the contact tip face. In some embodiments, the distance can be from about 2 mm to about 15 mm; or about 2 mm; or about 6 mm; or about 8 mm; or about 10 mm; or about less than about 2 mm; or about greater than about 15 mm.
In order to move the nozzle behind the contact tip, the distance of the cone can be decreased.
In contrast, some embodiments keep the same length of the cone and shift the entire nozzle back by shifting the thread location. In several embodiments, the thread counts can be kept the same.
Although
Although not specifically illustrated in previous
Many embodiments implement two cups in nozzles to expand gas coverage. Two-cup nozzles can be fabricated such as (but not limited to) printed in one-piece. The inner cup can be printed in a single piece, and the outer cup can be printed in a single piece. Post fabrication treatment such as (but not limited to) machining and/or heat treatment can be applied to the nozzles to achieve desired geometries, surface finishes, and/or mechanical properties. The inner cup and the outer cup can be fitted and assembled after printing. The inner and outer cup should form a seal such that no gas leakage should affect the flow of shielding gases in central channels and in outer channels.
The nozzle assembly 1000 has pressure chamber (or wall diffusers) 1014 to provide storage and transfer gas to the outer channels 1019. This can help to increase the amount of gas flow into the outer channels 1019. The cavity or chamber 1014 can be a pressure chamber for shielding gas to build up pressure to be fed into the outer channels 1019. The shielding gas can be fed into the chamber 1014 through inlets 1016. The inlet 1016 can extend outwardly from the chamber 1014 and be connected to a supply line of shielding gas. The inlet can take on any desired configuration and/or design such that it is capable of directing the shielding gas into the chamber 1014.
In various embodiments, the outer channels 1019 can be connected to the chamber or wall diffuser 1014 through one or more diffuser holes 1028. The diffuser holes 1028 can be positioned on the flange of the inner cup 1001 and transect the inner cup walls and connect the chamber 1014 with the outer channels 1019. The diffuser holes 1028. The diffuser holes 1028 can be positioned at a location within the chamber 1014 that allows for the high-pressure shielding gas to pass from the chamber 1014 into the outer channels 1019. The diffuser holes 1028 for the pressure chamber 1014 are offset from the inlets 1016. The offset diffuser holes from the inlets enable better gas diffusion from the chamber.
The shielding gas in central channels 1024 and the shielding gas in the outer channels 1019 can be flown at the same and/or different flow rate. The ability to have different flow rate in the channels enables better control of spatter build up in the nozzle. The inlets 1016 to the chambers 1014 can be positioned about 180 degrees apart from each other to provide access to various types of torches. The diameter of the inlets to the inner and outer high-pressure channels can be varied to achieve the desired gas flow. In various embodiments, the two-cup nozzle can have a pressure in the outer channels 1019 from about 20 psi to about 200 psi; or lower than about 20 psi; or higher than about 200 psi.
The outer cup that forms the outer channels 1019 can have varied diameters to reduce spatter buildup. Examples of the outer cup diameter can vary from about 25 mm to about 35 mm. In some embodiments, the diameter of the secondary cylindrical cup can be changed to modify gas coverage. In certain embodiments, the wall thickness can be changed in order to reduce the weight of the nozzle.
The thread 1018 on the distal end of the nozzle can connect with printing heads. Several embodiments shift the thread location relative to the rest of the nozzle to meet different fitting requirements. Many embodiments keep the same thread counts and/or thread geometries. Although nozzles in
The nozzle assembly 1100 has pressure chamber (or wall diffusers) 1114 to provide storage and transfer gas to the outer channels 1119. This can help to increase the amount of gas flow into the outer channels 1119. The cavity or chamber 1114 can be a pressure chamber for shielding gas to build up pressure to be fed into the outer channels 1119. The shielding gas can be fed into the chamber 1114 through inlets 1116. The inlet 1116 can extend outwardly from the chamber 1114 and be connected to a supply line of shielding gas. The inlet can take on any desired configuration and/or design such that it is capable of directing the shielding gas into the chamber 1114.
In various embodiments, the outer channels 1119 can be connected to the chamber or wall diffuser 1114 through one or more diffuser holes 1128. The diffuser holes 1128 can be positioned on the flange of the inner cup 1101 and transect the inner cup walls and connect the chamber 1114 with the outer channels 1119. The diffuser holes 1128 can be positioned at a location within the chamber 1114 that allows for the high-pressure shielding gas to pass from the chamber 1114 into the outer channels 1119. The diffuser holes 1128 for the pressure chamber 1114 are offset from the inlets 1116. The offset diffuser holes from the inlets enable better gas diffusion from the chamber.
Diffusers 1115 can be positioned inside the outer channels 1119. The diffusers can have various configurations such as 4-ring diffusers, 5-ring diffusers, 6-ring diffusers, and so on. Each ring of the diffuser comprises a plurality of holes. Diffuser 1115 is a 4-ring diffuser. Diffusers can be printed as an integral piece as the inner cup.
The shielding gas in central channels 1124 and the shielding gas in the outer channels 1119 can be flown at the same and/or different flow rate. The ability to have different flow rate in the channels enables better control of spatter build up in the nozzle. The inlets 1116 to the chambers 1114 can be positioned about 180 degrees apart from each other to provide access to various types of torches. The diameter of the inlets to the inner and outer high-pressure channels can be varied to achieve the desired gas flow. In various embodiments, the two-cup nozzle can have a pressure in the outer channels 1119 from about 20 psi to about 200 psi; or lower than about 20 psi; or higher than about 200 psi.
The outer cup that forms the outer channels 1119 can have varied diameters to reduce spatter buildup. Examples of the outer cup diameter can vary from about 25 mm to about 35 mm. In some embodiments, the diameter of the secondary cylindrical cup can be changed to modify gas coverage. In certain embodiments, the wall thickness can be changed in order to reduce the weight of the nozzle.
The thread 1118 on the distal end of the nozzle can connect with printing heads. Several embodiments shift the thread location relative to the rest of the nozzle to meet different fitting requirements. Many embodiments keep the same thread counts and/or thread geometries. Although nozzles in
The nozzle has a cutback distance of about 10 mm behind the contact tip face. The exit of the nozzle can have various geometries including (but not limited to) cone and smooth tangent circles. Some embodiments modify the exit geometry to affect the gas flow.
The nozzle assembly 1200 has pressure chamber (or wall diffusers) 1214 to provide storage and transfer gas to the outer channels 1219. This can help to increase the amount of gas flow into the outer channels 1219. The cavity or chamber 1214 can be a pressure chamber for shielding gas to build up pressure to be fed into the outer channels 1219. The shielding gas can be fed into the chamber 1214 through inlets 1216. The inlet 1216 can extend outwardly from the chamber 1214 and be connected to a supply line of shielding gas. The inlet can take on any desired configuration and/or design such that it is capable of directing the shielding gas into the chamber 1214.
In various embodiments, the outer channels 1219 can be connected to the chamber or wall diffuser 1214 through one or more diffuser holes 1228. The diffuser holes 1228 transect the inner cup walls of the nozzle and connect the chamber 1214 with the outer channels 1219. The diffuser holes 1228 can be positioned at a location within the chamber 1214 that allows for the high-pressure shielding gas to pass from the chamber 1214 into the outer channels 1219. The diffuser holes 1228 for the pressure chamber 1214 are offset from the inlets 1216. The offset diffuser holes from the inlets enable better gas diffusion from the chamber.
Diffusers 1215 can be positioned inside the outer channels 1219. The diffusers can have various configurations such as 4-ring diffusers, 5-ring diffusers, 6-ring diffusers, and so on. Each ring of the diffuser comprises a plurality of holes. Diffuser 1215 is a 4-ring diffuser. Diffusers can be printed as an integral piece as the inner cup.
The shielding gas in central channels 1224 and the shielding gas in the outer channels 1219 can be flown at the same and/or different flow rate. The ability to have different flow rate in the channels enables better control of spatter build up in the nozzle. The inlets 1216 to the chambers 1214 can be positioned about 180 degrees apart from each other to provide access to various types of torches. The diameter of the inlets to the inner and outer high-pressure channels can be varied to achieve the desired gas flow. In various embodiments, the two-cup nozzle can have a pressure in the outer channels 1219 from about 20 psi to about 200 psi; or lower than about 20 psi; or higher than about 200 psi.
The outer cup that forms the outer channels 1219 can have varied diameters to reduce spatter buildup. Examples of the outer cup diameter can vary from about 25 mm to about 35 mm. In some embodiments, the diameter of the secondary cylindrical cup can be changed to modify gas coverage. In certain embodiments, the wall thickness can be changed in order to reduce the weight of the nozzle.
Several embodiments implement two cups in nozzles to expand gas coverage. Outer cup of two-cup nozzles can be fabricated such as (but not limited to) printed in two pieces and inner cup of two-cup nozzles can be fabricated in one-piece. Post fabrication treatment such as (but not limited to) machining and/or heat treatment can be applied to the nozzles to achieve desired geometries and/or mechanical properties. The inner cup and the outer cup can be assembled and connected using screws, fasteners, latches, and/or adhesives.
The nozzle assembly 1300 has pressure chamber (or wall diffusers) 1314 to provide storage and transfer gas to the outer channels 1319. This can help to increase the amount of gas flow into the outer channels 1319. The cavity or chamber 1314 can be a pressure chamber for shielding gas to build up pressure to be fed into the outer channels 1319. The shielding gas can be fed into the chamber 1314 through inlets (not shown). The inlet can extend outwardly from the chamber 1314 and be connected to a supply line of shielding gas. The inlet can take on any desired configuration and/or design such that it is capable of directing the shielding gas into the chamber 1314.
In various embodiments, the outer channels 1319 can be connected to the chamber or wall diffuser 1314 through one or more diffuser holes 1328. The diffuser holes 1328 may locate on the flange of the inner cup and transect the inner cup walls of the nozzle and connect the chamber 1314 with the outer channels 1319. The diffuser holes 1328 can be positioned at a location within the chamber 1314 that allows for the high-pressure shielding gas to pass from the chamber 1314 into the outer channels 1319. The diffuser holes 1328 for the pressure chamber 1314 are offset from the inlets. The offset diffuser holes from the inlets enable better gas diffusion from the chamber.
The shielding gas in central channels 1324 and the shielding gas in the outer channels 1319 can be flown at the same and/or different flow rate. The ability to have different flow rate in the channels enables better control of spatter build up in the nozzle. The inlets to the chambers 1314 can be positioned about 180 degrees apart from each other to provide access to various types of torches. The diameter of the inlets to the inner and outer high-pressure channels can be varied to achieve the desired gas flow. In various embodiments, the two-cup nozzle can have a pressure in the outer channels 1319 from about 20 psi to about 200 psi; or lower than about 20 psi; or higher than about 200 psi.
The outer cup that forms the outer channels 1319 can have varied diameters to reduce spatter buildup. Examples of the outer cup diameter can vary from about 25 mm to about 35 mm. In some embodiments, the diameter of the secondary cylindrical cup can be changed to modify gas coverage. In certain embodiments, the wall thickness can be changed in order to reduce the weight of the nozzle.
Diffusers 1315 can be positioned inside the outer channels 1319. The diffusers can have various configurations such as 4-ring diffusers, 5-ring diffusers, 6-ring diffusers, and so on. Each ring of the diffuser comprises a plurality of holes. Diffuser 1315 is a 4-ring diffuser. Diffusers can be printed as an integral piece as the inner cup.
Although not specifically illustrated in previous
This description of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form described, and modifications and variations are possible in light of the teachings above. The embodiments were chosen and described to explain the principles of the invention and its practical applications. This description will enable others skilled in the art to best utilize and practice the invention in various embodiments and with various modifications as are suited to a particular use. The scope of the invention is defined by the following claims.
The current application claims the benefit of U.S. Provisional Patent Application No. 63/366,126, entitled “High Pressure Printing Head,” filed Jun. 9, 2022, and U.S. Patent Application No. 63/378,839, entitled “High Pressure Printing Head,” filed Oct. 7, 2022. The disclosures of U.S. Provisional Patent Application No. 63/366,126 and U.S. Patent Application No. 63/378,839 are incorporated by reference in their entirety for all purposes.
Number | Date | Country | |
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63366126 | Jun 2022 | US | |
63378839 | Oct 2022 | US |