Patent Application
20200087808
This invention generally relates to methods of electroforming nozzle structures (e.g., nozzle plates, valve guides, other nozzle structures, and combinations thereof that can be suitable for use in a fuel injector for an internal combustion engine), as well as other articles including microstructured features.
There are three basic types of fuel injector systems: port fuel injection (PFI), gasoline direct injection (GDI), and direct injection (DI). While PFI and GDI use gasoline as the fuel, DI uses diesel fuel. Efforts continue to further develop methods of manufacturing fuel injector nozzle structures (e.g., nozzle plates, otherwise known as director plates) and fuel injection systems containing the same so as to potentially increase fuel efficiency and reduce hazardous emissions of internal combustion engines, as well as reduce the overall energy requirements of a vehicle comprising an internal combustion engine.
The fuel injector systems use fuel injector nozzles including nozzle structures with through-holes to deliver fuel for combustion. Manufacturing of the nozzle structures can pose particular challenges in systems where control over the delivery of the fuel through the nozzle structures can improve or reduce efficiency of the engines.
The present invention is directed to methods of electroforming fuel injector nozzle structures such as, e.g., nozzle plates, valve guide structure, combinations of nozzle plate and valve guide structure, etc., as well as other articles incorporating microstructured features.
In one or more embodiments, the methods described herein can be used to electroform articles with high aspect ratio features in close proximity while reducing the likelihood of void formation during the electroforming process. Typically, the surfaces of structures to be electroformed are coated with a metal (e.g., silver or other conductive metal) coating to make the surface conductive—including vertical surfaces on high aspect ratio features. Referring to, e.g.,
Electroforming a metal structure (e.g., in the form of a plate) on the microstructured article 10 as depicted in
Voids in electroformed articles, such as, e.g., voids 52, are potential structural weak points in electroformed articles, and can lead to failure when the article is stressed either with temperature, pressure, or both. These problems may be particularly true when the electroformed articles are nozzle structures for use in fuel injection nozzles which are typically subjected to relatively high temperature and pressure during use. Reducing the likelihood of void formation can improve the durability of electroformed articles including microstructured features as described herein.
In one or more embodiments, methods of electroforming articles (such as, e.g., nozzle structures) as described herein comprise: forming a microstructured pattern of a first material, wherein the microstructured pattern comprises a plurality of microstructured features extending away from a base surface, wherein each microstructured feature of the plurality of microstructured features comprises a base proximate the base surface and a distal end located distal from the base surface, wherein the base surface is an electrically conductive surface, each microstructured feature has a non-uniform cross-section along its length and an electrically non-conductive surface between its base and distal end, wherein the plurality of microstructured features of the microstructured pattern are (i) discrete from each other, (ii) connected to each other, or (iii) a combination of both (i) and (ii); electroforming a metal structure (e.g., in the form of a plate) from the base surface after forming the microstructured pattern, wherein the metal structure extends away from the base surface and conforms to the electrically non-conductive surface of each microstructured feature; and removing the first material from the metal structure to make a microstructured metallic article comprising a negative of the microstructured pattern in the metal structure.
In one or more embodiments, the plurality of microstructured features comprises a pair of neighboring microstructured features comprising a first microstructure and a second microstructure, wherein a distance between the first microstructure and the second microstructure changes when moving in a direction away from the base surface towards the distal ends of the first and second microstructured features. In one or more embodiments, the distance increases. In one or more embodiments, the distance decreases. In one or more embodiments, the distance increases and decreases when moving in a direction away from the base surface towards the distal ends of the first and second microstructured features.
In one or more embodiments, the base of each microstructure of the plurality of microstructured features is completely surrounded by the electrically conductive base surface.
In one or more embodiments, the bases of the pair of neighboring microstructured features contact each other such that the base of neither microstructure of the pair of neighboring microstructured features is completely surrounded by the electrically conductive base surface.
In one or more embodiments, the plurality of microstructured features comprises three or more microstructured features, and wherein at least one microstructure of the three or more microstructured features comprises a base in contact with the bases of at least two microstructured features such that the base of at least one microstructure is not completely surrounded by the electrically conductive base surface.
In one or more embodiments, an entire surface of each microstructure of the plurality of microstructured features is electrically non-conductive.
In one or more embodiments, the base surface comprises an electrically conductive layer.
In one or more embodiments, a height of each microstructure of the plurality of microstructured features above the base surface is 2 millimeters or less.
In one or more embodiments, the microstructured metallic article comprises first and second major surfaces on opposite sides of the microstructured metallic article, wherein the microstructured metallic article comprises a plurality of through-holes extending from the first major surface to the second major surface, wherein each through-hole comprises a first opening on the first major surface and a second opening on the second major surface, and wherein each through-hole of the plurality of through-holes and its first and second openings have a shape defined by one microstructure of the plurality of microstructured features.
In one or more embodiments, forming the microstructured pattern of the first material comprises providing an amount (e.g., a layer or thickness) of the first material over the base surface followed by using a multiphoton process on the first material.
In a second aspect, one or more embodiments of methods of fabricating a microstructured metallic article as described herein may include: positioning an electrically conductive surface of a molding insert against a first major surface of a microstructured mold, wherein the microstructured mold comprises a second major surface on an opposite side of the microstructured mold from the first major surface, wherein the microstructured metallic mold comprises a plurality of cavities located therein, wherein each cavity of the plurality of cavities comprises a first opening on the first major surface, wherein the molding insert comprises a plurality of apertures, wherein each aperture of the plurality of apertures is aligned with a first opening of one of the cavities in the microstructured mold; delivering molding material into each cavity of the plurality of cavities of the microstructured mold; separating the microstructured mold from the molding material and the molding insert after delivering molding material into each cavity of the plurality of cavities of the microstructured mold, wherein the molding material forms a microstructured pattern comprising a plurality of microstructured features extending away from the electrically conductive surface of the molding insert, wherein each microstructured feature of the plurality of microstructured features comprises a base proximate the electrically conductive surface of the molding insert and a distal end located distal from the electrically conductive surface of the molding insert, and wherein each microstructured feature has an electrically non-conductive surface between its base and distal end; electroforming a metal structure (e.g., in the form of a plate) on the electrically conductive surface of the molding insert after separating the microstructured mold from the molding material and the molding insert, wherein the metal structure extends away from the electrically conductive surface of the molding insert and conforms to the electrically non-conductive surface of each microstructured feature; and removing the molding material from the metal structure to make a microstructured metallic article comprising a negative of the microstructured pattern in the metal structure.
In one or more embodiments of methods according to the second aspect, each microstructured feature of the plurality of microstructured features comprises a non-uniform cross-section along its length, wherein the plurality of microstructured features of the microstructured pattern are (i) discrete from each other, (ii) connected to each other, or (iii) a combination of both (i) and (ii).
The above summary is not intended to describe each embodiment or every implementation of the methods of manufacturing nozzle structures or other articles as described herein. Rather, a more complete understanding of the invention will become apparent and appreciated by reference to the following Detailed Description and claims in view of the accompanying figures of the drawing.
FIG.1 is a cross-sectional view of one exemplary micro-structured article including micro-structured features with a high aspect ratio.
In the following description, reference is made to the accompanying figures of the drawing which form a part hereof, and in which are shown, by way of illustration, specific embodiments. It is to be understood that other embodiments may be utilized and changes may be made without departing from the scope of the present invention.
The methods of manufacturing micro-structured articles (such as, e.g., nozzle structures) as described herein can, in one or more embodiments, use multiphoton (e.g., two photon) techniques, equipment and materials described in U.S. Pat. No. 9,333,598 B2 and US Patent Application Publication No. US 2013/0313339 (both titled “Nozzle and Method of Making Same”). In particular, multiphoton processes can be used to fabricate various microstructured patterns, which can, for example, include one or more hole forming features that may be used in, e.g., one or more nozzle structures used in fuel injectors. Further, the processes can, as described herein, be used to form nozzle structures (or other microstructured articles) themselves and/or as molds that can then be used to fabricate nozzle structures or other microstructured articles.
The microstructured articles described herein may, in one or more embodiments, be suitable for use as nozzle structures (including, e.g., nozzle plates, nozzle plate and valve guide structures, and other structural combinations) used in fuel injector nozzles. It should be understood that the term “nozzle” or “nozzle structure”, as used herein, may have a number of different meanings in the art. For example, U.S. Patent Publication No. 2009/0308953 A1 (Palestrant et al.), discloses an “atomizing nozzle” which includes a number of elements, including an orifice insert 24 and an occluder chamber 50. The understanding and definition of “nozzle structure” put forth herewith may, for example, include such structure like the orifice insert 24 of Palestrant et al. along with a portion, most or all of the structure corresponding to the chamber 50. In general, the nozzle structure of the current description can be understood as including the structure of an atomizing spray system from which the spray is ultimately emitted, see e.g., Merriam Webster's dictionary definition of nozzle (“a short tube with a taper or constriction used (as on a hose) to speed up or direct a flow of fluid.” Further understanding may be gained by reference to U.S. Pat. No. 5,716,009 (Ogihara et al.) issued to Nippondenso Co., Ltd. (Kariya, Japan). In this reference, again, fluid injection “nozzle” is defined broadly as the multi-piece valve element 10 (“fuel injection valve 10 acting as fluid injection nozzle . . .” —see col. 4, lines 26-27 of Ogihara et al.). The current definition and understanding of the term “nozzle structure” as used herein would relate, e.g., to first and second orifice plates 130 and 132, valve body 26, and potentially sleeve 138 (see
In one or more embodiments, nozzle structures manufactured using the methods described herein may include one or more nozzle through-holes strategically incorporated into the nozzle structure. The one or more nozzle through-holes may provide one or more of the following properties to the nozzle structure: (1) the ability to provide variable fluid flow through the nozzle (e.g., by opening or closing off one or more one or more nozzle through-holes), (2) the ability to provide multi- directional fluid flow relative to an outlet face of the nozzle structure, and (3) the ability to provide multidirectional off-axis fluid flow relative to a central normal line extending perpendicularly through the nozzle outlet face.
One embodiment of an illustrative method as described herein begins with formation of a microstructured pattern in material located on a substrate.
In one or more alternative embodiments, an electrically conductive layer 114 may also promote adhesion of microstructured features to a substrate that is already electrically conductive (i.e., improved adhesion as compared to adhesion provided by the materials forming the conductive substrate). Examples of such materials could include, e.g., titanium, indium tin oxide, etc.
Further, in one or more embodiments, the intermediate layer 116 may be optional. The optional intermediate layer 116 may, in one or more embodiments, be provided to improve attachment of the microstructrured features 140 to the base surface 112 formed by the electrically conductive layer 114 or to a base surface 112 formed directly on the substrate 100 when the substrate 100 is, itself, electrically conductive.
The intermediate layer 116 may, in one or more embodiments of the methods described herein, be selectively removable from those portions of the base surface 112 that are not located beneath the microstructured features 140 of a microstructured pattern formed on the base surface 112, particularly when the material used for the intermediate layer 116 is not electrically conductive enough for electroplating.
In one or more embodiments of the methods described herein the first material 118 in which the microstructured pattern is formed is capable of undergoing multiphoton reaction by simultaneously absorbing multiple photons. For example, in one or more embodiments, the first material is capable of undergoing a two photon reaction by simultaneously absorbing two photons. The first material can be any material or material system that is capable of undergoing multiphoton, such as two photon, reaction, such as those described in U.S. Pat. No. 7,583,444 (“Process For Making Microlens Arrays And Masteroforms”); U.S. Patent Application Publication US 2009/0175050 (“Process For Making Light Guides With Extraction Structures And Light Guides Produced Thereby”); and PCT Publication WO 2009/048705 (“Highly Functional Multiphoton Curable Reactive Species”).
In some cases, the first material can be a photoreactive composition that includes at least one reactive species that is capable of undergoing an acid- or radical-initiated chemical reaction, and at least one multiphoton photoinitiator system. Reactive species suitable for use in the photoreactive compositions include both curable and non-curable species. Exemplary curable species include addition-polymerizable monomers and oligomers and addition-crosslinkable polymers (such as free-radically polymerizable or crosslinkable ethylenically-unsaturated species including, for example, acrylates, methacrylates, and certain vinyl compounds such as styrenes), as well as cationically-polymerizable monomers and oligomers and cationically-crosslinkable polymers (which species are most commonly acid-initiated and which include, for example, epoxies, vinyl ethers, cyanate esters, etc.), and the like, and mixtures thereof. Exemplary non-curable species include reactive polymers whose solubility can be increased upon acid- or radical-induced reaction. Such reactive polymers include, for example, aqueous insoluble polymers bearing ester groups that can be converted by photogenerated acid to aqueous soluble acid groups (for example, poly(4-tert-butoxycarbonyloxystyrene). Non-curable species also include the chemically-amplified photoresists.
The multiphoton photoinitiator system enables polymerization to be confined or limited to the focal region of a focused beam of light used to expose the first material. Such a system preferably is a two- or three-component system that includes at least one multiphoton photosensitizer, at least one photoinitiator (or electron acceptor), and, optionally, at least one electron donor.
Examples of potentially suitable non-conductive materials for the optional intermediate layer 116 that improve attachment of the microstructured features 140 to the base surface 112 may include, but are not limited to, one or more nonconductive oxides or nitrides (with, e.g., materials with electrical conductivity too low for effective electroforming such as, e.g., titanium dioxide, titanium nitride, aluminum oxide, aluminum nitride, silicon dioxide, silicon nitride, etc.). Other materials that could be used as the intermediate layer 116 may include polymeric materials of similar composition to the first material 118 and can be used as an adhesion promoter. Silane materials may be desirable as such an adhesion promoter. Such intermediate layer materials could be deposited onto the substrate (via, e.g., sputter coating, physical vapor deposition, etc.) to promote adhesion of microstructured features to the substrate and then preferentially removed (by, e.g., chemical etching, etc.) after microstructured features are written. This would remove the intermediate layer everywhere except underneath the microstructured features (without affecting the substrate or microstructured features). It will be recognized that other non-conductive materials may be used for intermediate layers 116 to improve attachment of microstructured features 140 to the base surface 112. The first material 118 can be a material that is capable of undergoing multiphoton reaction by simultaneously absorbing multiple photons as described herein, or the first material 118 may not be a material that is capable of undergoing multiphoton reaction by simultaneously absorbing multiple photons as described herein. It can be desirable to choose the intermediate layer 116 so as to be compatible with the first material 118 being used.
The first material 118 can be supplied on the substrate 100 (and any intervening layers such as, e.g., optional electrically conductive layer 114, optional intermediate layer 116, etc.) using any method. Higher viscosity first materials may, for example, be coated on a substrate using any coating method that may be desirable in particular situation. For example, the first material could, in one or more embodiments, be coated on a substrate by flood coating. Other exemplary coating methods include knife coating, notch coating, reverse roll coating, gravure coating, spray coating, bar coating, spin coating and dip coating.
The first material 118 is, in one or more embodiments of the methods described herein, selectively exposed to an incident light having sufficient intensity to cause simultaneous absorption of multiple photons by the first material in the exposed region. The exposure can be accomplished by any method that is capable of providing light with sufficient intensity. Exemplary exposure methods and apparatus are described in U.S. Patent Application Publication US 2009/0099537 (“Process For Making Microneedles, Microneedle Arrays, Masters, And Replication Tools”).
After selective exposure of the first material 118 to define a microstructured pattern in the first material, the exposed first material is placed in a solvent to dissolve regions of higher solvent solubility. Exemplary solvents that can be used for developing the exposed first material may include, e.g., aqueous solvents such as, for example, water (for example, having a pH in a range of from 1 to 12) and miscible blends of water with organic solvents (for example, methanol, ethanol, propanol, acetone, acetonitrile, dimethylformamide, N-methylpyrrolidone, and the like, and mixtures thereof); and organic solvents. Exemplary useful organic solvents include alcohols (for example, methanol, ethanol, and propanol), ketones (for example, acetone, cyclopentanone, and methyl ethyl ketone), aromatics (for example, toluene), halocarbons (for example, methylene chloride and chloroform), nitriles (for example, acetonitrile), esters (for example, ethyl acetate and propylene glycol methyl ether acetate), ethers (for example, diethyl ether and tetrahydrofuran), amides (for example, N-methylpyrrolidone), and the like, and mixtures thereof.
Each of the microstructured features in a microstructured pattern as used in connection with the methods described herein may extend away from the base surface 112 and include a base 142 proximate the base surface 112 and a distal end 144 located distal from the base surface 112. As discussed herein, the surface surrounding the base 142 of each of the microstructured features 140 in a microstructured pattern as used in connection with the methods described herein is preferably electrically conductive such that electroformed metal deposits selectively on the surface surrounding the base 142 of each of the microstructured features 140.
Furthermore, each of the microstructured features includes an electrically nonconductive surface between its base and distal ends such that electroformed metal does not deposit directly on the microstructured features 140. This is in direct contrast with the methods described in, e.g., U.S. Pat. No. 9,333,598 B2 and US Patent Application Publication No. US 2013/0313339 in which the microstructured pattern itself is seeded with an electrically conductive layer or otherwise provided with an electrically conductive surface on which electroformed metal deposits during the electroforming process (such as, e.g., the microstructured features 40 depicted in
Although the surfaces of the microstructured features 140 of the microstructured pattern are not themselves electrically conductive, electroforming a metal structure (e.g., in the form of a plate, three-dimensional structure, etc.) from the base surface upwards after forming the microstructured pattern results in the metal structure extending away from the base surface 112, but conforming to the electrically nonconductive surfaces of each of the microstructured features 140 while reducing or eliminating the formation of voids between the microstructured features (such as, e.g., voids 52 described in connection with
Potentially useful methods of electroforming metal structures on electrically conductive surfaces may be described in, e.g., U.S. Pat. No. 9,333,598 B2 and US Patent Application Publication No. US 2013/0313339. The metals used for electroforming may be, e.g., elemental or alloyed metals (e.g., Ni, Co, and alloys that include one or both of these metals).
In one or more embodiments of the methods described herein, the microstructured features of microstructured patterns have a non-uniform cross-section. As used herein, “non-uniform cross-section” (and variations thereof) means that the cross-section of the microstructured feature changes in shape and/or size when moving along the length of the microstructured feature between its base and distal end. The cross-sections of the microstructured feature are taken in planes that are generally transverse to a length of the microstructured feature. The length of microstructured feature is defined along an axis that extends through the microstructured feature from its base end to its distal end (which, in one or more embodiments, may result in an axis that is in the form of a curved line to stay within the microstructured feature from its base end to its distal end).
In one or more embodiments of the methods described herein, the microstructured features in a microstructured pattern may include one or more pairs of neighboring microstructured features. The neighboring pairs of microstructured features may be described as having an inter-feature distance between the microstructured features that changes when moving in a direction away from the base surface towards the distal ends of the microstructured features. Moving in a direction away from the base surface toward the distal ends of the microstructured features results, in the exemplary embodiment depicted in, e.g.,
The inter-feature distance is measured in a distance generally transverse to the lengths of the microstructured features. In the context of the exemplary embodiment depicted in
In one or more embodiments of the methods of manufacturing microstructured articles as described herein, the microstructured features of the microstructured patterns of the microstructured articles may have a relatively limited or low height. This may be particularly true is used to manufacture nozzle structures for use in, e.g., fuel injector nozzles. In one or more exemplary embodiments, the height (h) of the microstructured features above a base surface on which the microstructured features are located (see, e.g., height (h) of microstructured features 40 above base surface 112 in
In one or more embodiments of methods of manufacturing microstructured articles with neighboring pairs of microstructured features in a microstructured pattern, at least one neighboring pair of microstructured features has an intermediate inter-feature distance (dint) measured at a distance of half the height (h) of the pair of neighboring microstructured features above the base surface. In one or more embodiments, a ratio of the height (h) of the microstructured features to the intermediate inter-feature distance (dint) may be 2:1 or more, 5:1 or more; or 10:1 or more. At the upper end, a ratio of the height (h) of the microstructured features to the intermediate inter-feature distance (dint) for one or more embodiments may be 300:1 or less, 250:1 or less, 200:1 or less, 150:1 or less, 120:1 or less, 100:1 or less, 80:1 or less, 50:1 or less, 20:1 or less, or 10:1 or less.
Removal of the portion of the intermediate layer 116 that is not located between the microstructured features 140 and the base surface 112 may be accomplished before or after forming the microstructured features 140. It may, however, be preferred and/or easier to remove the second portion of the intermediate layer 116 after forming the microstructured features 140 of the microstructured pattern.
In one or more embodiments such as that depicted in, e.g.,
With reference to
In such embodiments, the optional intermediate layer 116′ is provided on the conductive base surface 112′ formed by substrate 100′ (although the intermediate layer 116′ could be provided on an electrically conductive layer such as, e.g., layer 114 described in connection with
In one or more embodiments, intermediate layers provided on electrically conductive layers such as intermediate layer 116′ on conductive base surface 112′ to improve the release of an electroformed metal plate 150′ may take a variety for forms. Where, for example, the electrically conductive surface 112′ is stainless steel, the intermediate layer 116′ may be formed by a passivation process/method or surface treatment. In one or more embodiments the process may involve cleaning the metal forming the base surface in a degreasing solution and then placing the metal base surface into an acid solution/bath. The acid bath may be, e.g., a nitric acid solution with or without sodium dichromate, sodium dichromate, a citric acid solution, etc. Volume % of the acid is dependent on metal base surface being passivated, as well as, e.g., temperature and/or time in the bath. In one or more embodiments in which the base surface is, e.g., stainless steel, the process removes surface contaminants and free iron to allow for the very thin oxide layer, which naturally forms when exposed to air, to form over the surface.
In one or more embodiments of the methods described herein, the microstructured metallic article formed by electroformed metal plate 150 may be described as having a first major surface 152 and a second major surface 154, where the first and second major surfaces are located on opposite sides of the microstructured metallic article. Furthermore, the cavities 160 formed in the microstructured metallic article formed by electroformed metal plate 150 may be described as through-holes 160 extending from the first major surface 152 to the second major surface 154, wherein each through-hole 160 has a first opening 162 on the first major surface 152 and a second opening 164 on the second major surface 154. Each through-hole 160 and its first and second openings 162 and 164 have a shape defined by one microstructured feature 140 of the microstructured pattern depicted in, e.g.,
In one or more embodiments of the methods described herein, the through-holes 160 in the microstructured metallic article formed in the electroformed metal plate, or other structure, may have a length L as seen in
In one or more embodiments of the methods described herein, the microstructured metallic article provided by electroformed metal plate 150 (depicted in, e.g.,
A variety of exemplary neighboring pairs of microstructured features are depicted in
The neighboring pair of microstructured features 240 depicted in
The neighboring pair of microstructured features 340 depicted in
The microstructured features 440 of the neighboring pair of microstructured features 440 depicted in
Another manner in which one or more embodiments of the methods of manufacturing microstructured articles as described herein may be characterized is in the size of the bases of microstructured features in the microstructured pattern on the microstructured articles. For example, in one or more embodiments, the base of each microstructured feature of the microstructured pattern may occupy an area of 50 μm2 or more, 60 μm2 or more, 70 μm2 or more, 80 μm2 or more, or 100 μm2 or more on the base surface on which the microstructured features are located. At an upper end, the base of each microstructured feature in a microstructured pattern may, in one or more embodiments, occupy an area of 1 mm2 or less, 0.5 mm2 or less, 0.2 mm2 or less, 0.1 mm2 or less, or 0.05 mm2 or less on the base surface on which the microstructured features are located.
In one or more embodiments of the methods described herein, the base of one or more of the microstructured features forming the microstructured pattern is completely surrounded by an electrically conductive base surface. One example of such an embodiment is depicted in, e.g.,
In one or more alternative embodiments of the methods described herein, the bases of a pair of neighboring microstructured features may contact each other such that the base of neither microstructured feature of the pair of neighboring microstructured features is completely surrounded by an electrically conductive base surface. One example of such an embodiment is depicted in, e.g.,
In one or more further alternative embodiments of the methods described herein where the microstructured pattern includes three or more microstructured features 540 as depicted in, e.g.,
In one or more embodiments of methods of manufacturing microstructured articles as described herein, the method may include forming an intermediate layer that is not electrically conductive on the electrically conductive base surface before forming a microstructured pattern on the base surface. In such a method, the bases of the microstructured features of the microstructured pattern are formed on and cover a first portion of any such intermediate layer. One exemplary embodiment of a microstructured article including an intermediate layer on which microstructured features of a microstructured pattern are formed is depicted in
The microstructured pattern depicted in
Removal of the second portion of the intermediate layer 616 that is not located between the microstructured features 640 and the base surface 612 may be accomplished before or after forming the microstructured features 640. It may, however, be preferred and/or easier to remove the second portion of the intermediate layer 616 after forming the microstructured features 640 of the microstructured pattern.
In one or more embodiments of the methods described herein, the microstructured metallic article provided by electroformed metal plate 650 (as seen in, e.g.,
One exemplary replication process with which a mold (such as, e.g., a master mold manufactured according to the process that results in the mold depicted in
In one or more embodiments, at least the surface 774 of the molding insert 770 is an electrically conductive surface on which electroformed metal may be deposited. In one or more embodiments, the electrically conductive surface 774 may be provided in the form of a metallic layer on an otherwise nonconductive substrate forming molding insert 770. In one or more alternative embodiments, the molding insert 770 may be constructed of electrically conductive materials such that a separate electrically conductive coating is not needed to provide an electrically conductive surface 774 on the molding insert 770.
With the mold 650 and molding insert 770 thus positioned, molding material 680 may be delivered into the cavities 660 in the mold 650 as depicted in, e.g.,
After delivery of the molding material 680 into the cavities 660, the mold 650 may be removed from the molding material 680 filling cavities 660 as well as molding insert 770. One exemplary embodiment of the resulting structure is depicted in
The microstructured features 740 formed by this method may have any of the characteristics of the other microstructured features of microstructure patterns as described herein with respect to, e.g., shape, size, spacing, etc.
In one or more embodiments such as that depicted in, e.g.,
In one or more embodiments of the methods described herein, the microstructured metallic article formed by electroformed metal plate 750 may be completed and include the molding insert 770. In other words, in one or more methods as described herein, the molding insert 770 may form a part of any finished article.
In one or more alternative embodiments, the method may further include removal of the molding insert 770, with one exemplary embodiment of a resulting microstructured metallic article formed by electroformed metal plate 750 being depicted in
forming a microstructured pattern of a first material, wherein the microstructured pattern comprises a plurality of microstructured features extending away from a base surface, each microstructured feature of the plurality of microstructured features comprises a base proximate the base surface and a distal end located distal from the base surface, wherein the base surface is an electrically conductive surface, each microstructured feature has a non-uniform cross-section along its length and an electrically non-conductive surface between its base and distal end, and the plurality of microstructured features of the microstructured pattern are (i) discrete from each other, (ii) connected to each other, or (iii) a combination of both (i) and (ii);
electroforming a metal structure (e.g., in the form of a plate, three-dimensional structure, etc.) from the base surface after forming the microstructured pattern, wherein the metal structure extends away from the base surface and conforms to the electrically non-conductive surface of each microstructured feature; and
removing the first material from the metal structure to make a microstructured metallic article comprising a negative of the microstructured pattern in the metal structure. The metal structure can be suitable for making a nozzle structure such as, e.g., a nozzle plate, a combination nozzle plate and valve guide structure, etc.
positioning an electrically conductive surface of a molding insert against a first major surface of a microstructured mold, wherein the microstructured mold comprises a second major surface on an opposite side of the microstructured mold from the first major surface, wherein the microstructured metallic mold comprises a plurality of cavities located therein, wherein each cavity of the plurality of cavities comprises a first opening on the first major surface, wherein the molding insert comprises a plurality of apertures, wherein each aperture of the plurality of apertures is aligned with a first opening of one of the cavities in the microstructured mold;
delivering molding material into each cavity of the plurality of cavities of the microstructured mold;
separating the microstructured mold from the molding material and the molding insert after delivering molding material into each cavity of the plurality of cavities of the microstructured mold, wherein the molding material forms a microstructured pattern comprising a plurality of microstructured features extending away from the electrically conductive surface of the molding insert, wherein each microstructured feature of the plurality of microstructured features comprises a base proximate the electrically conductive surface of the molding insert and a distal end located distal from the electrically conductive surface of the molding insert, and wherein each microstructured feature has an electrically non-conductive surface between its base and distal end;
electroforming a metal structure on the electrically conductive surface of the molding insert after separating the microstructured mold from the molding material and the molding insert, wherein the metal structure extends away from the electrically conductive surface of the molding insert and conforms to the electrically non-conductive surface of each microstructured feature; and
removing the molding material from the metal structure to make a microstructured metallic article comprising a negative of the microstructured pattern in the metal structure.
It should be understood that although the exemplary methods are described as “comprising” one or more components, features or steps, the methods may “comprise,” “consists of,” or “consist essentially of any of the above-described components and/or features and/or steps. Consequently, where the present invention, or a portion thereof, has been described with an open-ended term such as “comprising,” it should be readily understood that (unless otherwise stated) the description of the present invention, or the portion thereof, should also be interpreted to describe the present invention, or a portion thereof, using the terms “consisting essentially of or “consisting of or variations thereof as discussed below.
As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having,” “contains”, “containing,” “characterized by” or any other variation thereof, are intended to encompass a non-exclusive inclusion, subject to any limitation explicitly indicated otherwise, of the recited components. For example, a method that “comprises” a list of elements (e.g., components or features or steps) is not necessarily limited to only those elements (or components or features or steps), but may include other elements (or components or features or steps) not expressly listed or inherent to the method.
As used herein, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a” or “the” component may include one or more of the components and equivalents thereof known to those skilled in the art. Further, the term “and/or” means one or all of the listed elements or a combination of any two or more of the listed elements.
Further, the term “comprises” and variations thereof do not have a limiting meaning where these terms appear in the accompanying description. Moreover, “a,” “an,” “the,” “at least one,” and “one or more” are used interchangeably herein.
As used herein, the transitional phrases “consists of and “consisting of exclude any element, step, or component not specified. For example, “consists of or “consisting of used in a claim would limit the claim to the components, materials or steps specifically recited in the claim except for impurities ordinarily associated therewith (i.e., impurities within a given component). When the phrase “consists of or “consisting of appears in a clause of the body of a claim, rather than immediately following the preamble, the phrase “consists of or “consisting of limits only the elements (or components or steps) set forth in that clause; other elements (or components) are not excluded from the claim as a whole.
As used herein, the transitional phrases “consists essentially of and “consisting essentially of are used to define a method that includes materials, steps, features, components, or elements, in addition to those literally disclosed, provided that these additional materials, steps, features, components, or elements do not materially affect the basic and novel characteristic(s) of the claimed invention. The term “consisting essentially of occupies a middle ground between “comprising” and “consisting of. Further, it should be understood that the herein-described methods may comprise, consist essentially of, or consist of any of the herein-described components and features, as shown in the figures with or without any additional feature(s) not shown in the figures. In other words, in some embodiments, the methods of the present invention may have any additional feature that is not specifically shown in the figures. In some embodiments, the methods of the present invention do not have any additional features other than those (i.e., some or all) shown in the figures, and such additional features, not shown in the figures, are specifically excluded from the methods.
The complete disclosure of the patents, patent applications, patent documents, and publications identified herein are incorporated by reference in their entirety as if each were individually incorporated. To the extent there is a conflict or discrepancy between this document and the disclosure in any such incorporated document, this document will control.
From the above disclosure of the general principles of the present invention and the preceding detailed description, those skilled in this art will readily comprehend the various modifications, re-arrangements and substitutions to which the present invention is susceptible, as well as the various advantages and benefits the present invention may provide. Therefore, the scope of the invention should be limited only by the following claims and equivalents thereof. In addition, it is understood to be within the scope of the present invention that the disclosed and claimed methods may be useful in other applications (i.e., in the manufacturing of articles other than fuel injector nozzle structures). Therefore, the scope of the invention may be broadened to include the use of the claimed and disclosed methods for such other applications.
The methods of manufacturing nozzle structures as discussed herein may be, in one or more embodiments, used in combination with the methods of manufacturing nozzle structures as discussed in and/or the nozzle structures described in the following co-pending applications: MAKING NOZZLE STRUCTURES ON A STRUCTURED SURFACE, U.S. Provisional Application No. 62/438,561, filed on Dec. 23, 2016 (Attorney Docket No. 77312US002) and NOZZLE STRUCTURES WITH THIN WELDING RINGS AND FUEL INJECTORS USING THE SAME, U.S. Provisional Application No. 62/438,558, filed on Dec. 23, 2016 (Attorney Docket No. 77311US002).
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IB2017/058299 | 12/21/2017 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62438567 | Dec 2016 | US |
