Development of electrochemical machining

Abstract

A mounting body for electrochemically machining a cavity of a component is disclosed. The mounting body includes an interface, at least a portion of an electrode, and a plurality of electrode channels. The engagement surface is engageable with the component to align the mounting body with the component. At least a portion of the electrode is coupled to the mounting body. A plurality of electrolyte channels extends at least partially through the mounting body. The downstream end portions of the plurality of electrolyte channels are distributed around at least a portion of the electrode.

Description

Technical Field

[0001] The present invention relates to mounting bodies, associated methods and components. Background Art

[0002] Electrochemical machining is a known process that is used to remove weld joints and polish internal passages of pipes. In this process, a positively charged workpiece forms an anode. The workpiece, or at least an exposed surface of the workpiece, is spaced (to define a gap) from a negatively charged electrode (which forms a cathode). An electrolyte is pumped through the gap provided between the workpiece and the electrode. The electrolyte effectively completes the circuit between the electrode and the workpiece (cathode and anode, respectively). As the electrons traverse the gap, atoms are removed from the exposed surface of the workpiece, resulting in an improved surface finish of the workpiece.

[0003] Existing electrochemical machining processes and associated equipment limit the use of the process to only some workpieces.As part of an effort to increase the range of components that can be used with the electrochemical machining process, the inventors have identified a number of other advantageous modifications to the process and associated equipment.

[0004] There exists a need to overcome one or more disadvantages associated with existing arrangements, whether mentioned herein or otherwise. Summary of the invention

[0005] According to a first aspect of the present invention, there is provided a mounting body for a chamber of an electrochemical machining component, the mounting body comprising: an engagement surface capable of engaging with the component to align the mounting body with the component; at least a portion of an electrode coupled to the mounting body; and a plurality of electrolyte channels extending at least partially through the mounting body; Wherein, downstream ends of the plurality of electrolyte channels are distributed around at least a portion of the electrode.

[0006] Electrochemical machining refers to a process (process) in which an electrolyte is passed through a gap between a negatively charged tool (cathode) and a positively charged workpiece (anode) to remove material from the workpiece. The electrolyte completes an electrical circuit (interrupted by the gap between the anode and cathode) to remove material from the workpiece and transport it away. In this case, it should be understood that the component is an example of a workpiece. The electrode is an example of a tool.

[0007] The cavity may have any of a variety of different shapes. For example, the cavity may be generally cylindrical (e.g., having a generally circular cross-section). Alternatively, the cavity may be generally cuboid (e.g., having a generally square or rectangular cross-section). The cavity may have a nonlinear geometry (i.e., the cavity may include one or more bends along its extension or length). The cavity may be a volute. Specifically, the cavity may be a volute formed in a housing of a turbine machine housing (e.g., a turbine housing or a compressor housing). The cavity may be defined by an opening. The cavity may have a discharge orifice. The electrolyte may flow through the opening of the cavity, flow along the inner wall of the cavity, and flow out via a discharge outlet. The cavity may be an internal cavity. The cavity may define a generally closed volume. The cavity may have an inlet and an outlet (e.g., a through hole).

[0008] The component may be any of a range of different components. Examples include a manifold, a turbomachine housing (e.g., a turbine housing or a compressor housing, or other type of pump housing), or an EGR valve. The component may be a turbine housing or a compressor housing of a turbocharger. When the component is a compressor housing, the compressor housing may be used for an eCompressor (i.e., a compressor driven by an electric motor or generator). An eCompressor may form part of an eTurbocharger. The component may be an engine component. The component may be made of a range of different conductive materials, including but not limited to aluminum, cast iron, and stainless steel.

[0009] For the purposes of this article, electrochemical machining of cavities refers to the effective polishing of prefabricated cavities. That is, cavities are not created, for example, by electrochemical machining processes on a solid surface. Instead, the surface finish of an existing cavity can be improved by reducing its surface roughness using electrochemical machining. This is because electrodes are inserted into the cavity in order to perform the process. In addition to polishing, the tolerance of the cavity dimensions can also be improved by electrochemical processes.

[0010] The mounting body may form part of an electrode assembly (e.g. where there are multiple components assembled together, such as conductive elements of an electrode, which can move relative to each other). The mounting body may form part of a flexible electrode (e.g. an electrode that deforms or flexes as it passes through a cavity to be processed). The mounting body itself may define a single-piece device in which the complete electrode is fixedly attached to the mounting body. Regardless of which device the mounting body forms part of, the device may include a single electrode. Alternatively, the device may include multiple electrodes (e.g. a pair of electrodes). Where there are two active cavities to be processed (e.g. a double inlet volute of a turbine housing), a device comprising multiple electrodes is advantageous. Where the device includes multiple electrodes, each electrode may be coupled to the mounting body (i.e. there may be only a single mounting body). The electrode may be referred to as an internal electrode.

[0011] At least a portion of the electrode forms part of the circuit. Examples of materials from which at least a portion of the electrode may be made include metals. While most wear-resistant metals are suitable, stainless steels (e.g., 300 series and 400 series stainless steels) are particularly desirable due to their corrosion resistance. 300 series and 316 series stainless steels have been found to be particularly effective.

[0012] At least a portion of the electrode may include a conductive element of a multi-part electrode. At least a portion of the electrode may include a flexible electrode. At least a portion of the electrode may include a single-piece electrode that is entirely rigid. At least a portion of the electrode may have a cross-section that varies along its extension. In other words, at least a portion of the electrode may not have a constant cross-section.

[0013] A mounting body coupled to at least a portion of an electrode may also be described as extending at least a portion of the electrode from the mounting body (e.g., an engagement surface of the mounting body). The mounting body may be fixed in place by, for example, a mounting fixture (e.g., a toggle clamp or a nail). Preferably, the component includes features such as an orifice, which itself may be used to support a nail, for example, which may be used to align the mounting body with the component. The mounting body may align at least a portion of the electrode within the cavity. That is, when taken at any point along a cross-section of the cavity, the electrode may be disposed substantially at the center of the cavity along the axis. By aligning the electrode within the cavity, a substantially continuous gap or void may be defined between the outer electrode surface and the inner wall defining the cavity. The gap between the outer electrode surface and the inner wall of the cavity is preferably between about 3 mm and about 6 mm in radius, but may be less than about 3 mm in some cases. The mounting body may be said to provide axial and rotational alignment of the electrode relative to the component. The mounting body may be described as protecting the electrode in a fixed manner.

[0014] The mounting body may be the only means by which the electrode is aligned in the cavity. Alternatively, other supports may be included. For example, the outer ends of the electrodes may be supported in the cavity by other supports. In the case where the component is a turbine housing, the other supports may be arranged to at least partially pass through the axial outlet (for a turbine housing) or the axial inlet (for a compressor housing).

[0015] The mounting body may include a gasket, which may be a non-conductive (electrical) gasket. The non-conductive gasket may seal or isolate a portion of the component (e.g., a flange) from the electrochemical machining circuit and process. As a result, the portion of the component may not be polished, or the material may be eroded. The engaging surface of the mounting body may indirectly engage the component to be machined, with the gasket being incorporated therein. That is, the gasket may be interposed between the engaging surface and the component.

[0016] The electrode may be electrically coupled to the mounting body. In use, a negative charge may be applied to (a portion of) the mounting body (e.g., an integral bus bar) so as to apply a negative charge to the electrode. Thus, the mounting body may generally constitute a cathode. The electrode may be described as a protruding feature.

[0017] The electrolyte channel may extend across or through the entire extent of the mounting body between the engagement surface and the rear face of the mounting body (eg between the two major faces of the mounting body).The electrolyte channel may be distributed around the periphery of the electrode.

[0018] The plurality of electrolyte channels may include four electrolyte channels. The electrolyte channel may be described as a discharge channel. The plurality of electrode channels may be offset from the periphery of the electrode and distributed around the periphery of the electrode. The downstream ends of the plurality of electrolyte channels may be described as discharge orifices. The downstream ends of the plurality of electrolyte channels may be described as electrolyte entry points around the electrode (and into the cavity to be processed). The downstream ends of the electrolyte channels may be defined in the joint surface of the mounting body, or may be recessed relative to the joint surface. The electrolyte channels may be holes. The electrolyte channels may be inclined in the direction of electrolyte flow. Each of the plurality of electrolyte channels may be equal in volume. The electrolyte is preferably evenly distributed between each of the plurality of electrolyte channels. The electrolyte channels may each define an equal effective flow area through it. In an embodiment where the component to be processed includes a plurality of cavities having different (e.g., unequal) cross-sectional areas (e.g., a turbine housing having two volutes having different cross-sectional areas at a given point), the electrolyte channels of the corresponding array (e.g., their downstream ends) may be adjusted to provide a uniform (e.g., equal) flow of electrolyte through each cavity. That is, the size and / or geometry of the downstream end of the electrolyte channel (eg, the drain orifice) may be varied to adjust the velocity of electrolyte flow through the cavity, and thus the mass flow rate.

[0019] Advantageously, including multiple electrolyte channels distributed around the electrode results in a more uniform distribution of electrolyte flow around the electrode during electrochemical machining. It has been found that this can avoid undesirable flow characteristics, such as recirculation zones where insulating hydroxides (a byproduct of electrochemical machining) may be recirculated and reduce the efficiency of electrochemical machining or prevent electrochemical machining from occurring in these zones.

[0020] The electrolyte channels may be referred to as an electrolyte transport system. The distribution of the electrolyte channels may be said to be form-fitting to (eg, conforming to) the outer surface of the electrode.

[0021] The downstream ends of the plurality of electrolyte channels may be evenly distributed around the electrode.

[0022] The uniform distribution encompasses that the electrolyte channels define a substantially repeating pattern, wherein adjacent electrolyte channels are equally spaced apart, except for any minor deviations to allow a driving device (e.g., a flexible element, such as a rope) to extend through the electrode (if a driving device is present). In other words, the repeating pattern or uniform distribution may not be perfectly uniform or equal for each electrolyte channel, and there may be minor deviations. Specifically, it may be the downstream end of a plurality of orifices uniformly distributed around the electrode. The distribution may be around the periphery of the electrode.

[0023] Uniform distribution is intended to encompass both a continuous uniform distribution (e.g., the downstream ends of the electrolyte channels extend around the entire periphery of the electrode in a generally repeating pattern) and a discontinuous uniform distribution (e.g., the downstream ends of two series of electrolyte channels are disposed on either side of the electrode and are uniformly distributed only along these two sides).

[0024] In embodiments including multiple electrodes, a corresponding plurality or array of electrolyte channels may be distributed around each electrode.

[0025] It has been discovered that uniform distribution of the downstream ends of the electrolyte channels is desirable to evenly distribute the electrolyte around the electrode, thereby enabling more efficient electrochemical machining.

[0026] The downstream ends of the plurality of electrolyte channels may be offset from the electrode.

[0027] In other words, the downstream end of the electrolyte channel does not extend through the electrode, but is offset from the periphery of the electrode, but still distributed around the periphery of the electrode.

[0028] Advantageously, it has been found that offsetting the ends of the electrolyte channels from the electrodes can reduce turbulence in the electrolyte flow and more smoothly direct the electrolyte flow over and along the outer surfaces of the electrodes.

[0029] A plurality of electrolyte channels may extend through the electrode.

[0030] The channel may extend through the electrode between internal cavities within the electrode.

[0031] The electrolyte channel may be an arc-shaped cavity.

[0032] The arcuate cavity refers to the cross-sectional geometry of at least the downstream end of the electrolyte channel. In a preferred embodiment, the downstream end of the electrolyte channel occupies or extends about one quarter of the circumference of the electrode. In this way, the combination of four electrolyte channels effectively extends around the entire circumference of the electrode. For embodiments with n electrolyte channels, the downstream end of the electrolyte channel preferably occupies about a 1 / n ratio of the circumference of the electrode (close to the mounting body).

[0033] Advantageously, the electrolyte channel being an arcuate cavity means that the flow can be smoothly directed around an at least partially arcuate electrode.

[0034] The electrolyte channel may vary in cross-sectional area from the upstream end to the downstream end.

[0035] The electrolyte channel may increase in cross-sectional area (eg normal to the flow direction) from the upstream end to the downstream end. Alternatively, the electrolyte channel may decrease in cross-sectional area from the upstream end to the downstream end.

[0036] Advantageously, the variation in cross-sectional area of ​​the electrolyte channels means that electrolyte conduits may be used to feed the electrolyte channels whilst the electrolyte channels direct flow around (eg around the periphery of) the electrodes to provide efficient electrochemical machining.

[0037] The electrolyte channel may be defined by one or more ribs.

[0038] One or more ribs may be tapered at the upstream end.One or more ribs may have a generally streamlined geometry at the upstream end.

[0039] Each electrolyte channel is preferably defined by at least two ribs. A rib is a generally elongated body of material that is relatively thin relative to its length. At least one rib may separate each electrolyte channel from another.

[0040] Advantageously, it has been found that such a geometry can split (e.g. divide) (a large portion of) the electrolyte flow without causing swirl and / or turbulence in the electrolyte flow. The presence of one or more ribs also advantageously provides a larger surface area in contact with the electrolyte, so that the electrolyte can be charged through the mounting body (wherein the electrolyte conduit is electrically connected to the mounting body [e.g., integral with the mounting body]) before the electrolyte enters the cavity to be processed. This can be referred to as pre-charging.

[0041] Defining the electrolyte channels with ribs also provides a relatively high effective flow area through the electrolyte channels (eg, reduces or avoids flow restrictions).

[0042] One or more of the ribs may have a reduced cross-sectional area at the upstream end.

[0043] Advantageously, the reduced cross-sectional area at the upstream end of the one or more ribs divides and directs flow through the electrolyte channels.

[0044] At least a portion of the electrode may be coupled to one or more ribs.

[0045] At least a portion of the electrode may be integral with the mounting body.

[0046] The mounting body being integral with at least a portion of the electrode is intended to encompass arrangements where the mounting body and the first conductive element of the electrode are manufactured as a single body. The mounting body being integral with at least a portion of the electrode is also intended to encompass arrangements where the mounting body and the conductive element are manufactured separately and are joined in a subsequent manufacturing step (e.g., welding). In other embodiments, the entire electrode may be integral with the mounting body (e.g., the electrode may not be formed of multiple conductive elements).

[0047] Advantageously, integrating at least a portion of the electrode with the mounting body significantly improves the alignment of the electrode within the cavity to be machined. This is particularly advantageous for electrochemical machining, where the gap between the outer electrode surface and the inner wall of the cavity is an important parameter.

[0048] The mounting body may further include an electrolyte conduit located upstream of and in fluid communication with the plurality of electrolyte channels.

[0049] The electrolyte conduit may alternatively be referred to as an electrolyte supply or electrolyte feed. The electrolyte conduit has an extent (e.g., length), which may be axial (i.e., straight) or may include one or more arcuate portions (e.g., bends). The electrolyte conduit preferably has a circular cross-section. The electrolyte conduit may be external (e.g., a protruding or extended tube) or internal (e.g., extending within the mounting body).

[0050] The electrolyte conduit may be made of a conductive material. The electrolyte conduit may be made of the same material as the mounting body. The electrolyte conduit may be in electrical communication with the mounting body (eg, so that the two components may be maintained at the same electrical potential).

[0051] Advantageously, the electrolyte conduit provides electrolyte for the electrochemical machining process to the mounting body in a uniform manner. The electrolyte conduit may be integral with the mounting body (e.g., including the electrolyte conduit being manufactured as a single component with the mounting body, and the electrolyte conduit being connected to the mounting body in a separate manufacturing process (e.g., welding)).

[0052] The electrolyte conduit may have an extension around at least about one major dimension of a cross-section of the conduit.

[0053] The extension of the electrolyte conduit may be referred to as the length of the electrolyte conduit. In the case where the electrolyte conduit is a circular conduit (e.g., a circular tube), the main dimension may be referred to as a diameter, preferably an inner diameter. For a rectangular conduit, the main dimension of the cross section is the longer side of the rectangle. If the electrolyte conduit has a variable cross section, the main diameter refers to the largest (inner) main diameter. However, the electrolyte conduit preferably has a uniform or constant cross section. The extension of the electrolyte conduit may extend until the point where the electrolyte flow is separated (e.g., upstream of the electrolyte channel).

[0054] Advantageously, it has been found that an electrolyte conduit having an extension at least equal to the major dimension of the cross section of the conduit provides the desired flow directing properties and also provides a degree of pre-charging of the electrolyte at the point where the conduit is electrically connected to the mounting body.

[0055] The electrolyte conduit may have an extension at least equal to about three or more times a major dimension of a cross section of the conduit.

[0056] The electrolyte conduit may have an extent of at least about six times a major dimension of a cross-section of the conduit.

[0057] Advantageously, it has been found that the electrolyte conduit has an extension equal to at least about six times the major dimension of the cross-section of the conduit, providing the desired pre-charging effect for the electrolyte. In addition, it has been found that the electrolyte conduit of about six times the major dimension in length can provide low turbulence electrolyte to the electrolyte channel, thereby achieving efficient electrochemical machining.

[0058] The electrolyte conduit may have an extension equal to about six times the major dimension of the cross-section of the conduit.

[0059] According to a second aspect of the present invention, there is provided a method for electrochemically machining a cavity of a component using a mounting body according to the first aspect of the present invention, the method comprising: coupling the mounting body to the component to align at least a portion of the electrode within the cavity; and A negative charge is applied to at least a portion of the electrode, and an electrolyte flow is provided through the plurality of electrolyte channels to distribute electrolyte around at least a portion of the electrode and remove material from an inner wall of the cavity.

[0060] The component may be grounded. Grounding the component means that substantially all static electricity is discharged from the component. Advantageously, this means that while the electrode is negatively charged and thus forms a cathode, the workpiece effectively forms an anode due to its larger positive charge. Grounding the component, in conjunction with providing an electrolyte, thus completing an electrical circuit, facilitates electrochemical machining of the component. The component may be connected to the positive terminal of a power source (to define a cathode). The electrode (and optionally the mounting body) may be connected to the negative terminal of a power source (to form an anode).

[0061] Before the mounting body is coupled to the component, the method may further include inserting at least a portion of the electrode through the opening (e.g., into the cavity). At least a portion of the electrode can be said to run through the cavity. Inserting at least a portion of the electrode along the cavity means that the electrode at least partially passes through the extension range or length of the cavity. At least a portion of the electrode may pass through the entire cavity, i.e., the distal end of at least a portion of the electrode may abut against the end wall, endpoint or end of the cavity. Alternatively, at least a portion of the electrode may only partially extend through the cavity. That is, in use, there may still be a certain range in the cavity that is not occupied by at least a portion of the electrode. The above also applies more generally to the entire electrode (e.g., beyond at least a portion of the electrode).

[0062] The opening may be a circular opening or an opening having other geometric shapes. The opening may also be referred to as an orifice.

[0063] Coupling the mounting body to the component may be achieved by the mounting body engaging the component directly or indirectly. The mounting body may be temporarily secured to the component using a temporary securing device. Examples include the use of nails that may align holes of the mounting body with corresponding holes in the component, or the use of a toggle clamp to secure the mounting body to the component. In a preferred arrangement, and where the component is a turbine machine housing, the mounting body may specifically engage a flange of the turbine machine housing.

[0064] Aligning at least a portion of the electrode within the cavity means that at least a portion of the electrode is substantially centered within the cavity when viewed in cross-section such that a substantially continuous gap or void exists around an exterior of at least a portion of the electrode and an interior wall of the cavity.

[0065] Aligning at least a portion of the electrode within the cavity may include the outer electrode surface being form-fitted with at least a portion of an inner wall of the cavity (e.g., such that the outer electrode surface generally follows the contour of the inner wall of at least a portion of the extension of the cavity when moving from the opening toward the distal end of the cavity). As described above, in use, the entire electrode may not be placed along the entire length of the cavity, and thus the electrode may only partially extend along the extent of the cavity. The outer electrode surface is preferably form-fitted with an extension of the inner wall of the cavity that is substantially equal to the length of the electrode. In other words, the electrode is preferably form-fitted with the cavity along the entire length of the electrode.

[0066] Applying a negative charge to at least a portion of the electrode means that at least a portion of the electrode is negatively charged. In other words, the electrode is a cathode in the above-mentioned electrochemical machining process. The negative charge can be applied by connecting at least a portion of the electrode to a power source. The power source can be a DC (direct current) power source.

[0067] The electrodes can be electrically connected to a power source, which can be a DC power source. If necessary, the DC power source can also be easily adjusted. In some embodiments, the joints between the conductive elements can electrically couple the conductive elements together, so that the power source is even indirectly connected to the outermost conductive elements.

[0068] The DC power source may have an output current strength of at least about 100 A. It has been found that a DC power source having an output current strength of at least 100 A is effective for use in electrochemical machining processes. The output current strength may be about 140 A, or about 1 kA, or about 1.5 kA or 2.5 kA. The output current strength may be up to about 5 kA.

[0069] The DC power supply may have an output voltage of at least about 10V. It will be appreciated that the output voltage may be -10V, depending on which terminal the output is taken from. The output voltage may be about 20V, about 30V, or about 40V. For health and safety reasons, the output voltage preferably does not exceed about 50V.

[0070] The power supply may provide about 1.5 kA at about 40 V (ie, a 60 kW power supply). The power supply may provide about 2.5 kA at about 40 V (ie, a 100 kW power supply).

[0071] Providing an electrolyte flow may include pumping the electrolyte. Pumping the electrolyte may provide an electrolyte flow. The electrolyte may be a saline solution or any other fluid that provides an ion flow. A weakly acidic solution is another example of a suitable electrolyte. The electrolyte may include sodium nitrate and / or sodium chloride. The concentration may range from about 15% to about 30% by volume. In the case of a combination including sodium nitrate and sodium chloride, the ratio of sodium nitrate to sodium chloride may be, for example, about 80:20, about 70:30, or about 60:40 by volume. The electrolyte may be composed of 100% sodium nitrate, with a concentration between about 15% and about 30% by volume.

[0072] Pumping the flow of electrolyte through the cavity can be described as forcing the electrolyte to flow through the opening, along the cavity, and out of the cavity via the exhaust outlet. The flow of electrolyte can suspend material removed from the inner wall, pass through the cavity, and out of the cavity via the exhaust outlet.

[0073] Removing material from the inner wall may be referred to as polishing the inner wall. Removing material from the inner wall may alternatively be referred to as reducing the surface roughness of the inner wall. Removing material from the inner wall may be referred to as improving the surface finish of the inner wall.

[0074] The component, the mounting body and at least a portion of the electrode (optionally the entire electrode) are preferably held in a fixed relationship to each other during electrochemical machining. In other words, there is preferably no relative movement between the mounting body, any portion of the electrode and the component during electrochemical machining.

[0075] The method is not limited to performing the steps in the order listed in the claims. For example, a negative charge may be applied to the electrode prior to inserting the electrode through the opening and along the cavity (although in practice, it is contemplated that the electrode is fully inserted into the cavity prior to turning on power and applying the charge). Similarly, an electrolyte may be pumped through the cavity prior to inserting the electrode. That is, the electrode may be inserted prior to applying the negative charge to the electrode. Similarly, an electrolyte may be pumped through the cavity after inserting the electrode, and optionally after applying the negative charge to the electrode.

[0076] The electrolyte may include a liquid electrolyte. The electrolyte may consist of a liquid electrolyte. The liquid electrolyte may be, for example, a saline solution (e.g., water having salt dissolved therein).

[0077] The electrolyte may include multiple bodies. The multiple bodies may be solid bodies. The electrolyte may be composed of multiple bodies (e.g., solid bodies). The multiple bodies may be conductive or non-conductive. For example, the electrolyte may include a solid medium (which may be conductive or non-conductive). The multiple bodies may include multiple beads (e.g., spherical particles) or other shapes of solids (e.g., not spherical in geometry). The multiple bodies may be entrained in a medium such as a liquid or gas. The medium may be conductive or non-conductive. The multiple bodies may be considered to flow, optionally by being entrained in the medium. The multiple bodies (e.g., solid media) may be used in combination with an electrolyte fluid, or may be used alone (e.g., not combined with an electrolyte liquid).

[0078] According to a third aspect of the present invention, there is provided a mounting body for a chamber of an electrochemical machining component, the mounting body comprising: an engagement surface engageable with the component to align the mounting body with the component; and an electrolyte conduit configured to receive a flow of electrolyte; wherein the electrolyte conduit has an extent of at least about one time a major dimension of a cross section of the conduit; and Wherein, the electrolyte pipe is electrically connected to the mounting body.

[0079] Electrochemical machining refers to a process in which an electrolyte is passed through a gap between a negatively charged tool (cathode) and a positively charged workpiece (anode) to remove material from the workpiece. The electrolyte completes an electrical circuit (interrupted by the gap between the anode and cathode) to remove material from the workpiece and transport it away. In this context, it should be understood that the component is an example of a workpiece. The electrode is an example of a tool.

[0080] The cavity may have any of a variety of different shapes. For example, the cavity may be generally cylindrical (e.g., having a generally circular cross-section). Alternatively, the cavity may be generally cuboid (e.g., having a generally square or rectangular cross-section). The cavity may have a nonlinear geometry (i.e., the cavity may include one or more bends along its extension or length). The cavity may be a volute. Specifically, the cavity may be a volute formed in a housing of a turbine machine housing (e.g., a turbine housing or a compressor housing). The cavity may be defined by an opening. The cavity may have a discharge orifice. The electrolyte may flow through the opening of the cavity, flow along the inner wall of the cavity, and flow out via a discharge outlet. The cavity may be an internal cavity. The cavity may define a generally closed volume. The cavity may have an inlet and an outlet (e.g., a through hole).

[0081] The component may be any of a range of different components. Examples include a manifold, a turbomachine housing (e.g., a turbine housing or a compressor housing, or other type of pump housing), or an EGR valve. The component may be a turbine housing or a compressor housing of a turbocharger. When the component is a compressor housing, the compressor housing may be used for an eCompressor (i.e., a compressor driven by an electric motor or generator). An eCompressor may form part of an eTurbocharger. The component may be an engine component. The component may be made of a range of different conductive materials, including but not limited to aluminum, cast iron, and stainless steel.

[0082] For the purposes of this article, electrochemical machining of cavities refers to the effective polishing of pre-fabricated cavities. That is, cavities are not created, for example, on a solid surface, by the electrochemical machining process. Instead, the surface finish of an existing cavity can be improved by reducing the surface roughness of the existing cavity using electrochemical machining. This is because an electrode is inserted into the cavity to allow the process to take place. In addition to polishing, the tolerance of the cavity dimensions can also be improved by the electrochemical process.

[0083] The mounting body may form part of an electrode assembly (e.g., in which there are multiple components assembled together, such as conductive elements of the electrode, which can move relative to each other). The mounting body may form part of a flexible electrode (e.g., the electrode deforms or flexes as the electrode passes through a cavity to be processed). The mounting body itself may define a single-piece device in which the complete electrode is fixedly attached to the mounting body. Regardless of which device the mounting body forms part of, the device may include a single electrode. Alternatively, the device may include multiple electrodes (e.g., a pair of electrodes). Where there are two effective cavities to be processed (e.g., a double inlet volute of a turbine housing), a device comprising multiple electrodes is advantageous. Where the device includes multiple electrodes, each electrode may be coupled to the mounting body (i.e., there may be only a single mounting body). The electrode may be referred to as an internal electrode.

[0084] The mounting body and electrolyte conduit form part of an electrical circuit. Examples of materials from which the mounting body and electrolyte conduit may be made include metals. While most wear-resistant metals are suitable, stainless steels (e.g., 300 series and 400 series stainless steels) are particularly desirable due to their corrosion resistance. 300 series and 316 series stainless steels have been found to be particularly effective.

[0085] The mounting body can be fixed in place by, for example, a mounting fixture (e.g., a toggle clamp or a nail). Preferably, the component includes features such as an orifice, which itself can be used to support a nail, for example, which can be used to align the mounting body with the component. The mounting body can align the electrode substantially centrally within the cavity. That is, when intercepted at any point along the cross-section of the cavity, the electrode can be set substantially centrally in the cavity along the axis. By aligning the electrode within the cavity, a substantially continuous gap or void can be defined between the outer electrode surface and the inner wall defining the cavity. The gap between the outer electrode surface and the inner wall of the cavity is preferably between about 3 mm and about 6 mm in radius, but in some cases it can be less than about 3 mm. The mounting body can be said to provide axial and rotational alignment of the electrode relative to the component. The mounting body can be described as fixing the electrode in a fixed manner.

[0086] The mounting body may include a gasket, which may be a non-conductive (electrical) gasket. The non-conductive gasket may seal or isolate a portion of the component (e.g., a flange) from the circuit and process of electrochemical machining. As a result, the portion of the component may not be polished, or have material erosion. The engaging surface of the mounting body may indirectly engage the component to be machined, with the gasket also being incorporated therein. That is, the gasket may be interposed between the engaging surface and the component.

[0087] The mounting body may include an integral bus bar. The bus bar being integral with the mounting body encompasses the mounting body and the bus bar being a single component. The bus bar may include one or more holes that may act as a socket into which the electrical connection may be received. The socket may receive a plug (e.g., a copper or stainless steel plug) to aid in the connection.

[0088] Advantageously, by integrating the bus bar with the mounting body, the voltage drop between the bus bar and the mounting body can be reduced.During electrochemical machining, it is desirable to keep the voltage drop low to maintain high efficiency.

[0089] In use, a negative charge may be applied to (a portion of) the mounting body (e.g., an integral bus bar) so that a negative charge is applied to the mounting body. Thus, the mounting body may substantially constitute a cathode. The negative charge is also applied to the electrolyte conduit via an electrical connection.

[0090] The extension of the electrolyte conduit may be referred to as the length of the electrolyte conduit. In the case where the electrolyte conduit is a circular conduit (e.g., a circular tube), the main dimension may be referred to as the diameter, preferably the inner diameter. For a rectangular conduit, the main dimension of the cross section is the longer side of the rectangle. If the electrolyte conduit has a variable cross section, the main diameter refers to the largest (inner) main diameter. However, the electrolyte conduit preferably has a uniform or constant cross section. The extension of the electrolyte conduit may extend until the point where the electrolyte flow is separated (e.g., upstream of the electrolyte channel).

[0091] Advantageously, it has been found that an electrolyte conduit having an extension at least equal to the major dimension of the cross section of the conduit provides the desired flow directing properties and also provides a degree of pre-charging of the electrolyte due to the electrical connection of the conduit to the mounting body. Pre-charging refers to the effective charging of the electrolyte before it encounters the electrode and provides improved electrochemical machining results at the upstream end of the chamber.

[0092] The electrolyte conduit may have an extension at least equal to about three or more times a major dimension of a cross section of the conduit.

[0093] The electrolyte conduit may be integral with the mounting body.

[0094] The electrolyte duct being integrated with the mounting body is intended to cover that the mounting body and the electrolyte duct are manufactured as a single body. The electrolyte duct being integrated with the mounting body is also intended to cover an arrangement where the mounting body and the electrolyte duct are manufactured separately and joined together in a subsequent manufacturing step (eg welding).

[0095] Advantageously, the electrolyte conduit being integral to the mounting means that both components are maintained at the same electrical potential, which aids the pre-charging effect.

[0096] The electrolyte conduit may have an extension at least equal to about three times a main dimension of a cross section of the conduit.

[0097] The electrolyte conduit may have an extent of at least about six times a major dimension of a cross-section of the conduit.

[0098] Advantageously, it has been found that the electrolyte conduit has an extension equal to at least about six times the major dimension of the cross-section of the conduit, providing the desired pre-charging effect for the electrolyte. In addition, it has been found that the electrolyte conduit of about six times the major dimension in length can provide low turbulence electrolyte to the electrolyte channel, thereby achieving efficient electrochemical machining.

[0099] The electrolyte conduit may have an extension equal to about six times the major dimension of the cross-section of the conduit.

[0100] The mounting body and the electrolyte conduit may be made of the same material.

[0101] Advantageously, the mounting body and the electrolyte conduit being made of the same material means that the two components can be more easily maintained at the same electrical potential.

[0102] The electrolyte conduit may be axial in extension.

[0103] The electrolyte conduit having an axial extension may also be described as the electrolyte conduit being straight. The electrolyte conduit in other embodiments may include one or more arcuate portions (eg bends).

[0104] The mounting body may also include at least a portion of the electrode coupled to the mounting body.

[0105] At least a portion of the electrode may include a conductive element of a multi-part electrode. At least a portion of the electrode may include a flexible electrode. At least a portion of the electrode may include a single-piece electrode that is entirely rigid. At least a portion of the electrode may have a cross-section that varies along its extension. In other words, at least a portion of the electrode may not have a constant cross-section. The electrode may be described as a protruding feature.

[0106] The mounting body may also include a plurality of electrolyte channels extending at least partially through the mounting body, the plurality of electrolyte channels being disposed downstream of the electrolyte conduit.

[0107] The electrolyte passage may extend across or through the entire extent of the mounting body between the engagement surface and the rear face of the mounting body (eg, between the two major faces of the mounting body).

[0108] The plurality of electrolyte channels may include four electrolyte channels. The electrolyte channel may be described as a discharge channel. The plurality of electrode channels may deviate from the periphery of the electrode and be distributed around the periphery of the electrode. The downstream ends of the plurality of electrolyte channels may be described as discharge orifices. The downstream ends of the plurality of electrolyte channels may be described as electrolyte entry points around the electrode (and into the cavity to be processed). The downstream ends of the electrolyte channels may be defined in the joint surface of the mounting body, or may be recessed relative to the joint surface. The electrolyte channel may be a hole. The electrolyte channel may be inclined in the direction of electrolyte flow. Each of the plurality of electrolyte channels may be equal in volume. The electrolyte is preferably evenly distributed between each of the plurality of electrolyte channels. The electrolyte channels may each define an equal effective flow area through it.

[0109] Advantageously, the inclusion of multiple electrolyte channels results in a more even distribution of electrolyte flow during electrochemical machining. It has been found that this can avoid undesirable flow characteristics, such as recirculation zones where insulating hydroxides (a byproduct of electrochemical machining) may be recirculated and reduce the efficiency of electrochemical machining or prevent electrochemical machining from occurring in these zones.

[0110] The distribution of the electrolyte channels may be form-fitted to (eg, conform to) the outer surface of the electrode.

[0111] The downstream ends of the plurality of electrolyte channels may be distributed around at least a portion of the electrode.

[0112] The electrolyte channel may be an arc-shaped cavity.

[0113] The arcuate cavity refers to the cross-sectional geometry of at least the downstream end of the electrolyte channel. In a preferred embodiment, the downstream end of the electrolyte channel occupies or extends about one quarter of the circumference of the electrode. In this way, the combination of four electrolyte channels effectively extends around the entire circumference of the electrode. For embodiments with n electrolyte channels, the downstream ends of the electrolyte channels are preferably distributed in about a 1 / n ratio of the circumference of the electrode (close to the mounting body).

[0114] Advantageously, the electrolyte channel being an arcuate cavity means that the flow can be smoothly directed around an at least partially arcuate electrode.

[0115] The electrolyte channel may vary in cross-sectional area from the upstream end to the downstream end.

[0116] The electrolyte channel may increase in cross-sectional area (eg normal to the flow direction) from the upstream end to the downstream end. Alternatively, the electrolyte channel may decrease in cross-sectional area from the upstream end to the downstream end.

[0117] Advantageously, the variation in cross-sectional area of ​​the electrolyte channels means that electrolyte conduits may be used to feed the electrolyte channels whilst the electrolyte channels direct flow around (eg around the periphery of) the electrodes to provide efficient electrochemical machining.

[0118] The electrolyte channel may be defined by one or more ribs.

[0119] The one or more ribs may be tapered at the upstream end.The one or more ribs may have a generally streamlined geometry at the upstream end.

[0120] Each electrolyte channel is preferably defined by at least two ribs. A rib is a generally elongated body of material that is relatively thin relative to its length. At least one rib may separate each electrolyte channel from another.

[0121] Advantageously, it has been found that such a geometry can split (e.g. divide) (most of) the electrolyte flow without causing swirl and / or turbulence in the electrolyte flow. The presence of one or more ribs also advantageously provides a larger surface area in contact with the electrolyte, so that the electrolyte can be charged by the mounting body before the electrolyte enters the cavity to be processed. This can be referred to as pre-charging.

[0122] Defining the electrolyte channels with ribs also provides a relatively high effective flow area through the electrolyte channels (eg, reduces or avoids flow restriction).

[0123] One or more of the ribs may have a reduced cross-sectional area at the upstream end.

[0124] Advantageously, the reduced cross-sectional area at the upstream end of the one or more ribs divides and directs flow through the electrolyte channels.

[0125] The electrodes may be coupled to one or more ribs.

[0126] The electrodes may be integral with the mounting body.

[0127] The mounting body being integral with at least a portion of the electrode is intended to encompass that the mounting body and the first conductive element of the electrode are manufactured as a single body. The mounting body being integral with at least a portion of the electrode is also intended to encompass an arrangement where the mounting body and the conductive element are manufactured separately and joined together in a subsequent manufacturing step (e.g., welding). In other embodiments, the entire electrode may be integral with the mounting body (e.g., the electrode may not be formed of multiple conductive elements).

[0128] Advantageously, integrating at least a portion of the electrode with the mounting body significantly improves the alignment of the electrode within the cavity to be machined. This is particularly advantageous for electrochemical machining, where the gap between the outer electrode surface and the inner wall of the cavity is an important parameter.

[0129] According to a fourth aspect of the present invention, there is provided a method for electrochemically machining a cavity of a component using a mounting body according to the third aspect of the present invention, the method comprising: applying a negative charge to the mounted body, and thus to the electrolyte conduit, and providing an electrolyte flow through the electrolyte conduit; pre-charging the electrolyte as it flows through the electrolyte conduit toward the cavity; and The pre-charged electrolyte is discharged into the cavity to remove material from the inner wall of the cavity.

[0130] The component may be grounded. Grounding the component means that substantially any static electricity is discharged from the component. Advantageously, this means that while the mounting body and electrolyte conduit are negatively charged and thus form a cathode, the workpiece effectively forms an anode due to having a larger positive charge. Grounding the component, in conjunction with providing an electrolyte, thus completing an electrical circuit, facilitates electrochemical machining of the component. The component may be connected to the positive terminal of a power source (to define a cathode). The mounting body may be connected to the negative terminal of a power source (to form an anode).

[0131] Prior to coupling the mounting body to the component, the method may further comprise inserting at least a portion of the electrode through the opening (e.g., into the cavity). At least a portion of the electrode may be said to extend through the cavity. Inserting at least a portion of the electrode along the cavity means that the electrode at least partially extends through the extension or length of the cavity. At least a portion of the electrode may extend through the entire cavity, i.e., the distal end of at least a portion of the electrode may abut against an end wall, an endpoint, or an end of the cavity. Alternatively, at least a portion of the electrode may extend only partially through the cavity. That is, in use, there may still be a certain extension in the cavity that is not occupied by at least a portion of the electrode. The above also applies more generally to the entire electrode (e.g., beyond at least a portion of the electrode).

[0132] The component, the mounting body and at least a portion of the electrode (optionally the entire electrode) are preferably held in a fixed relationship to each other during electrochemical machining. In other words, there is preferably no relative movement between the mounting body, any portion of the electrode and the component during electrochemical machining.

[0133] The opening may be a circular opening or an opening having other geometric shapes. The opening may also be referred to as an orifice.

[0134] Coupling the mounting body to the component may be achieved by the mounting body engaging the component directly or indirectly. The mounting body may be temporarily secured to the component using a temporary securing device. Examples include the use of nails that may align holes of the mounting body with corresponding holes in the component, or the use of a toggle clamp to secure the mounting body to the component. In a preferred arrangement, and where the component is a turbine machine housing, the mounting body may specifically engage a flange of the turbine machine housing.

[0135] The method may also include coupling the mounting body to the component to align the mounting body relative to the component (and in some embodiments, to align at least a portion of the electrode within the cavity to be processed). Aligning at least a portion of the electrode within the cavity means that at least a portion of the electrode is substantially centered within the cavity when viewed in cross-section such that a substantially continuous gap or void exists around an exterior of at least a portion of the electrode and an interior wall of the cavity.

[0136] Aligning at least a portion of the electrode within the cavity may include the outer electrode surface being form-fitted to at least a portion of an inner wall of the cavity (e.g., such that the outer electrode surface generally follows the contour of the inner wall of at least a portion of the extension of the cavity when moving from the opening toward the distal end of the cavity). As described above, in use, the entire electrode may not be placed along the entire length of the cavity, and thus the electrode may only partially extend along the extent of the cavity. The outer electrode surface is preferably form-fitted to an extent of the inner wall of the cavity that is substantially equal to the length of the electrode. In other words, the electrode is preferably form-fitted to the cavity along the entire length of the electrode.

[0137] Applying a negative charge to the mounting body means that the mounting body is negatively charged. In other words, the mounting body is a cathode in the above-mentioned electrochemical machining process. The negative charge can be applied by connecting the mounting body to a power source. The power source can be a DC (direct current) power source.

[0138] The mounting body may be electrically connected to a power source, which may be a DC power source which may also be easily regulated if desired.

[0139] The DC power source may have an output current strength of at least about 100 A. It has been found that a DC power source having an output current strength of at least 100 A is effective for use in electrochemical machining processes. The output current strength may be about 140 A, or about 1 kA, or about 1.5 kA or 2.5 kA. The output current strength may be up to about 5 kA.

[0140] The DC power supply may have an output voltage of at least about 10V. It will be appreciated that the output voltage may be -10V, depending on which terminal the output is taken from. The output voltage may be about 20V, about 30V, or about 40V. For health and safety reasons, the output voltage preferably does not exceed about 50V.

[0141] The power supply may provide about 1.5 kA at about 40 V (ie, a 60 kW power supply). The power supply may provide about 2.5 kA at about 40 V (ie, a 100 kW power supply).

[0142] Discharging the precharged electrolyte can be described as discharging the electrolyte, optionally through the downstream end of the electrolyte channel. Providing an electrolyte flow can include pumping the electrolyte. Pumping the electrolyte can provide an electrolyte flow. The electrolyte can be a salt water or any other fluid that provides an ion flow. A weakly acidic solution is another example of a suitable electrolyte. The electrolyte can include sodium nitrate and / or sodium chloride. The concentration can range from about 15% to about 30% by volume. In the case of a combination of sodium nitrate and sodium chloride, the ratio of sodium nitrate to sodium chloride can be, for example, about 80:20, about 70:30, or about 60:40 by volume. The electrolyte can be composed of 100% sodium nitrate, with a concentration between about 15% and about 30% by volume.

[0143] Pumping the flow of electrolyte through the cavity can be described as forcing the electrolyte to flow through the opening, along the cavity, and out of the cavity via the exhaust outlet. The flow of electrolyte can suspend material removed from the inner wall, pass through the cavity, and out of the cavity via the exhaust outlet.

[0144] Removing material from the inner wall may be referred to as polishing the inner wall. Removing material from the inner wall may alternatively be referred to as reducing the surface roughness of the inner wall. Removing material from the inner wall may be referred to as improving the surface finish of the inner wall.

[0145] The electrolyte may include a liquid electrolyte. The electrolyte may consist of a liquid electrolyte. The liquid electrolyte may be, for example, a saline solution (e.g., water having salt dissolved therein).

[0146] The electrolyte may include multiple bodies. The multiple bodies may be solid bodies. The electrolyte may be composed of multiple bodies (e.g., solid bodies). The multiple bodies may be conductive or non-conductive. For example, the electrolyte may include a solid medium (which may be conductive or non-conductive). The multiple bodies may include multiple beads (e.g., spherical particles) or other shapes of solids (e.g., not spherical in geometry). The multiple bodies may be entrained in a medium such as a liquid or gas. The medium may be conductive or non-conductive. The multiple bodies may be considered to flow, optionally by being entrained in the medium. The multiple bodies (e.g., solid media) may be used in combination with an electrolyte fluid, or may be used alone (e.g., not combined with an electrolyte liquid).

[0147] The component may be a turbine housing or a compressor housing for a turbocharger, and the cavity may be a turbine housing volute or a compressor housing volute, respectively.

[0148] The cross-sectional area of ​​the volute varies along the extent or length of the volute. That is, the volute has a non-constant cross-sectional area or shape normal to the length of the volute. This can alternatively be described as an overall taper.

[0149] For a compressor housing volute, the cross section may transition from a generally smaller circular to a generally larger circular (moving from the opening to the discharge outlet). In the case of a turbine housing volute, the cross section may transition from a generally larger rectangular to a generally smaller rectangular. It should be understood that these shapes are by way of example only, and that various other geometric shapes, including complex cross-sectional shapes, may be combined in other ways.

[0150] For a turbine housing volute, the width (i.e., major dimension) of a cross section defined by a cross section extending along the arcuate extent of the volute may decrease from about 80 mm (close to the turbine housing inlet) to about 15 mm (away from the turbine housing inlet). The height (i.e., minor dimension) of the cross section may decrease from about 100 mm (close to the turbine housing inlet) to about 40 mm (away from the turbine housing inlet). The width of the cross section may be taken in the axial direction. The height of the cross section may be taken in the radial direction.

[0151] For the compressor housing volute, the cross-section may be generally circular, and the corresponding diameter may decrease from about 100 mm (close to the compressor housing outlet) to about 15 mm (far from the compressor housing outlet).

[0152] The extent or length of the volute can be said to be arcuate. That is, moving from the opening of the volute to the endpoint or distal end, the midpoint of the cavity (i.e., the midpoint of the cross-section) is generally arcuate. The volute can be said to extend partially around the circumference of a circle. The geometry can alternatively be described as generally snail-shell-like or partially helical. The volute can also extend in a direction away from the plane of the helix. That is, the volute can be spring-like or partially helical. In other words, the geometry along the length of the volute can be similar to the geometry that would appear if a generally circular ring of flexible material were cut and the two ends were pushed in opposite axial directions.

[0153] The volute may be between about 250 mm and about 2000 mm in extension (ie length). This may correspond to a housing with the centreline of the volute being disposed at a diameter of between about 150 mm and about 600 mm.

[0154] The turbine housing may be a double volute housing. The turbine housing may be an asymmetric housing.

[0155] The electrode may extend through at least about 50% of the extension of the volute. It is advantageous for the electrode to extend through at least about 50% of the extension of the volute because a large proportion of the volute may be processed during chemical processing of the electrode. The electrode may extend through at least about 80% of the extension of the volute, or at least about 85% of the extension of the volute.

[0156] The distal end of the volute may not be occupied by the electrode during use. The performance benefits obtained by electrochemically machining the distal end of the volute may be less than other parts of the volute, so it is preferred not to electrochemically machine the distal end of the volute. The electrode may terminate between about 5 mm and about 25 mm from the distal end of the volute. The electrode may be described as extending toward the end or end of the tail of the volute. In some arrangements, the entire extension of the volute may be occupied by the electrode. That is, the electrode may extend through the entire extension of (for example) a compressor housing volute or a turbine housing volute.

[0157] The electrodes may be between less than about 250 mm and about 2000 mm in extension (ie, length).

[0158] According to a fifth aspect of the present invention, there is provided a computer program comprising computer executable instructions which, when executed by a processor, cause the processor to control an additive manufacturing apparatus to manufacture a mounting body according to the first or third aspect of the present invention.

[0159] According to a sixth aspect of the present invention, there is provided a method for manufacturing an electrode or a conductive element of the electrode by additive manufacturing, the method comprising: obtaining an electronic file representing the geometric shape of the mounting body according to the first aspect or the third aspect of the present invention; and An additive manufacturing device is controlled to manufacture the electrode or the conductive element of the electrode in one or more additive manufacturing steps according to the geometric shape specified in the electronic file.

[0160] According to a seventh aspect of the present invention, there is provided a component comprising a cavity electrochemically machined using a mounting body according to the first or third aspect of the present invention and / or using a method according to the second or fourth aspect of the present invention.

[0161] The component may be any component comprising a fluid conduit, such as a manifold, an EGR valve, an engine block or a turbomachine housing, in particular a turbine housing or a compressor housing for a turbocharger.

[0162] When the component is a turbine housing or a compressor housing for a turbocharger, the cavity may be a turbine housing volute or a compressor housing volute, respectively.

[0163] Where appropriate, optional and / or preferred features listed herein for each aspect of the invention may also be applicable to any other aspect of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0164] Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0165] Figure 1 A known electrochemical machining process is schematically depicted;

[0166] Figure 2a and Figure 2b is a perspective view of an electrode assembly;

[0167] Figure 3a is a perspective view of an alternative electrode in a movable configuration;

[0168] Figure 3b yes Figure 3a A perspective view of an electrode being transformed into a form-fitting configuration;

[0169] Figure 3c to Figure 3e yes Figure 3a and Figure 3b Various views of electrodes in a form-fitting configuration;

[0170] Figure 4 is a cross-sectional view of the turbine housing, where Figure 2a and Figure 2b The electrode is inserted into its volute;

[0171] Figure 5is a perspective view of a mounting body according to an embodiment of the present invention;

[0172] Figure 6a and Figure 6b is a perspective view of a mounting body according to another embodiment;

[0173] Figure 6c and Figure 6d yes Figure 6a and Figure 6b A perspective cross-sectional view of a mounting body;

[0174] Figure 7 is a perspective cross-sectional view of a mounting body according to another embodiment;

[0175] Figure 8 is a perspective view of a portion of a mounting body according to another embodiment;

[0176] Fig. 9 Shown are the Figure 7 Results of computational fluid dynamics (CFD) simulations of the electrode assembly of the mounted body;

[0177] Fig.10 shows the results of CFD simulations performed on a modified electrode assembly;

[0178] Fig.11 Shown are the Figure 8 Results of CFD simulations of the electrode assembly of the mounted body;

[0179] Fig.12a and Figure 12b is a perspective view of an electrode assembly including a mounting body according to another embodiment;

[0180] Fig.12c yes Fig.12a and Figure 12b a perspective cutaway view of a portion of the electrode assembly shown;

[0181] Fig.13 and Fig.14 Shows the Figures 12a to 12c Results of CFD simulations of electrode components;

[0182] Fig.15a and Fig.15b is a perspective view of an electrode assembly including a mounting body according to another embodiment;

[0183] Figures 16a to 16c is a perspective view of an electrode assembly including a mounting body according to another embodiment;

[0184] Fig.17 is a perspective view of an electrode assembly including a mounting body according to another embodiment;

[0185] Fig.18a and Fig.18b yes Fig.17 A perspective view of an electrode assembly mounted in situ and coupled to a compressor housing;

[0186] Fig.19 Used when machining turbine housings Figures 12a to 12c Table of experimental data obtained for the electrode assembly;

[0187] Fig. 20 yes Fig.19 A plot of some of the data shown indicates the relationship between pipe length and surface finish;

[0188] Fig.21 It is used when processing compressor housing. Figures 12a to 12c Table of experimental data obtained for the electrode assembly;

[0189] Fig. 22 yes Fig.21 A plot of some of the data shown indicates the relationship between pipe length and surface finish; and

[0190] Fig.23 is a plot indicating the relationship between the pipe length and the Reynolds number of the electrolyte flow. DETAILED DESCRIPTION

[0191] Figure 1 is a schematic diagram of a known electrochemical machining process.

[0192] The power source 2 may be a DC power source, with which a negative charge is applied to the electrode 4. This may be done by means of the electrode 4 being electrically connected to the negative terminal of the power source 2. The electrode 4 thus forms a cathode. The power source is preferably a DC power source (electricity supply).

[0193] By electrically connecting the part 6 to be processed to the positive terminal of the power supply 2, or alternatively, by connecting the part 6 to ground (i.e., grounding the part), a positive charge can be effectively applied to the part 6 to be processed. As long as the part 6 has a more positive charge than the electrode 4, the part forms an anode.

[0194] A gap 10 is provided between the electrode 4 and the component 6. Specifically, the gap 10 is provided between the electrode 4 and the electrode-facing surface 7 or exposed surface of the component 6. The gap 10 may also be referred to as a void.

[0195] A flow of electrolyte 8 is pumped through the gap 10 between the electrode 4 and the component 6 (specifically, the electrode-facing surface 7 of the component 6). Since the electrolyte is conductive, the flow of electrolyte 8 effectively completes the circuit. As electrons flow across the gap 10, material from the electrode-facing surface 7 of the component 6 is dissolved or removed. It should also be understood that material will be removed from the electrode-facing surface 7 in a manner that generally conforms to the geometry of the electrode 4. The electrolyte 8 then transports the removed material downstream of the component 6 and the electrode 4.

[0196] The electrodes used in the prior art processes limit the geometries that can be machined by electrochemical machining. Specifically, given that the electrode 4 is in a face-to-face relationship with the electrode-facing surface 7 of the component 6, and there is a gap 10 for the flow of electrolyte 8, the prior art methods and apparatus may not be suitable for use with more complex component geometries.

[0197] Figure 2a and Figure 2b 1 is a perspective view of the electrode assembly 100. The electrode assembly 100 includes two electrodes 102, 104, a mounting body 106 and two driving devices 105, 107 in the form of ropes. It should be noted that Figure 2a and Figure 2b The mounting body 106 of the present invention is not an embodiment of the present invention. However, these figures are included to demonstrate the operation of the electrodes 102, 104, which can be used in conjunction with the mounting body according to the present invention (an embodiment of which will be described in detail in the accompanying drawings). Figure 5 and subsequent figures).

[0198] Although the illustrated electrode assembly 100 includes two electrodes 102 , 104 , it should be understood that in some embodiments, the electrode assembly may include only a single electrode.

[0199] Each electrode 102, 104 includes a plurality of conductive elements. With respect to the first electrode 102, the first electrode 102 includes five conductive elements 108, 110, 112, 114, 116. It should be noted that Figure 2a 1. The join line between the third conductive element 112 and the fourth conductive element 114 is obscured from view in FIG. 1. With respect to the second electrode 104, the second electrode 104 includes corresponding five conductive elements 118, 120, 122, 124, 126. The fifth conductive element 116, 126 of each of the first electrode 102 and the second electrode 104 may be referred to as an outermost conductive element because it is located at a maximum distance from the mounting body 106 along the length of the electrode. The distal end of each of the fifth or outermost conductive elements 116, 126 defines an outermost tip 117, 127 of the electrode 102, 104.

[0200] In use, the mounting body 106 engages with a component to be machined so that the electrodes 102, 104 are aligned within the cavity of the component. An example of an electrode being aligned within a volute (an example of a cavity to be machined) is shown in FIG. Figure 4 and will be described in detail later in this article.

[0201] Return to Figure 2a , the mounting body 106 is in the form of a mounting flange. The mounting flange is generally cubic and defines a joint surface 128, which, in use, engages with a corresponding surface (e.g., flange) of the component to be processed (e.g., directly or indirectly through the insertion of a gasket). Two bosses 130, 132 are provided in the joint surface 128, and the two bosses 130, 132 protrude from the joint surface 128. The first conductive elements 108, 118 of the electrodes 102, 104 are respectively connected to the mounting body 106 at their respective bosses 130, 132. The connection can be made in a variety of different ways, including bolt connections (such as Figure 2b as shown).

[0202] Four holes 134, 136, 138, 140 are also defined in the mounting body 106 (hole 136 is located at Figure 2a Holes 134, 136, 138, 140 are used to align the mounting body 106 and thus the electrodes 102, 104 with the component.

[0203] In the case where the component to be machined is a compressor housing, for example, the mounting body of the electrode assembly can be aligned with a substantially tangential outlet of the compressor housing (as opposed to a substantially tangential inlet of the turbine housing). The outlet of the compressor housing can be circular. The mounting body can be aligned with or engaged with the inner and / or outer surface of the compressor housing outlet. This is particularly advantageous in the case where the compressor housing outlet does not include any mounting holes or flanges and instead uses (for example) a V-band clamp to connect to the proximal pipe (in use). The compressor housing outlet can have a normal diameter. The compressor housing outlet can include a clamp retaining feature, such as a half V-band or a half Marmon flange. The feature can match a corresponding feature of the pipe and the two features can be secured using a V-band clamp to connect the compressor to the pipe. The engagement of the electrode assembly with the compressor housing outlet facilitates the insertion of the electrode through the compressor housing outlet, rather than inserting the electrode through the (for example) tangential outlet of the compressor housing.

[0204] The mounting body of the electrode assembly can be said to engage with existing features of the component to be machined in order to align the electrode assembly, and thereby the electrode, with the component and cavity.

[0205] Return to Figure 2a, the conductive elements and electrodes 102, 104 more generally have two different configurations: a movable configuration and a conforming configuration.

[0206] exist Figure 2a , electrodes 102, 104 are shown in a form-fitting configuration, wherein each constituent conductive element is rigidly engaged with one or more adjacent conductive elements. When held in the form-fitting configuration, relative movement between the conductive elements is substantially prevented.

[0207] In terms of the overall concept, Figure 3a to Figure 3c As shown, the conductive elements can move relative to each other in a movable configuration. For example, the outermost conductive elements 116, 126 ( Figure 2a ) can move relative to the adjacent fourth conductive elements 114, 124.

[0208] When the electrodes 102, 104 are in a movable configuration, wherein the conductive elements are able to move relative to each other, the relative movement facilitates insertion of the electrodes 102, 104 into a cavity, and particularly into more complex cavities. For example, a volute of a turbine machine housing (such as Figure 4 104) presents a relatively challenging cavity into which to insert electrodes for an electrochemical machining process. However, if relative movement between the conductive elements is allowed, such as in a movable configuration, the electrodes 102, 104 can be gradually fed into the volute while the conductive elements move relative to each other. Due to the interaction between the inner wall of the volute and the outer surface of the conductive elements, the conductive elements can move relative to each other. Once the electrodes 102, 104 are inserted sufficiently deep into the cavity, the electrodes 102, 104 are transformed into a form-fitting configuration (i.e., Figure 2a and Figure 2b ), so that the conductive elements of each respective electrode 102, 104 are aligned with each other so as to define a substantially continuous outer electrode surface 101, 103. The outer electrode surface 101, 103 is then arranged to align with the inner wall of the cavity (e.g., Figure 4 The inner wall (eg, 268 in FIG. 6 ) is in a face-to-face relationship and is disposed at a substantially constant gap, clearance, or offset from the inner wall (eg, 270 in FIG. 6 ). Although the cavity has a relatively complex geometry, electrochemical machining of the cavity can still be performed.

[0209] As previously mentioned, in the illustrated embodiment, the electrode assembly 100 includes two ropes 105, 107, which may be referred to as a first rope and a second rope, respectively. The ropes 105, 107 are examples of one type of flexible element suitable for use with the present invention. Although the following description refers to ropes 105, 107, it should be understood that the description is equally applicable to other types of flexible elements (e.g., wires). Each rope includes two ends, such as Figure 2a The cords 105, 107 extend through the conductive elements of the respective first and second electrodes 102, 104. When it is desired to transform the electrodes 102, 104 into a form-fitting configuration (i.e. once the electrodes have been inserted into the cavity), the cords 105, 107 are actuated by tensioning the cords 105, 107 in a direction away from the mounting body 106 so as to draw the conductive elements into engagement with each other. Figure 3a Move to Figure 3b and then to Figure 3c Return to Figure 2a and Figure 2b , the ropes 105, 107 can then be fixed so that the conductive elements and more generally the electrodes 102, 104 are held in a form-fitting configuration. As described above, in the form-fitting configuration, for each electrode 102, 104, the outer surfaces of the respective conductive elements are aligned with each other to define a substantially continuous outer electrode surface. At the phase connection between consecutive or adjacent conductive elements, there are only minor discontinuities in the outer electrode surface.

[0210] When it is desired to release or withdraw the electrodes 102, 104, the tension on the cords 105, 107 can be released and the assembly 100 can be withdrawn by driving the assembly 100 away from the component. As the separation between the mounting body 106 and the component increases, the electrodes 102, 104 are gradually withdrawn from the cavity. The relative contact between the outer surfaces of the electrodes 102, 104 (and specifically the conductive elements thereof) can drive the conductive elements to move relative to each other to facilitate the withdrawal of the electrodes 102, 104. In other words, when the outer surfaces of the conductive elements engage the inner wall of the cavity, the conductive elements can be driven to move relative to each other.

[0211] It should be understood that Figure 2a and Figure 2b In the embodiment, the first conductive elements 108, 118 remain coupled to the mounting body 106 in a fixed manner (i.e., permanently coupled and fixed relative to each other). In this way, the electrodes 102, 104 can be moved from the second conductive elements 110, 120 and subsequent conductive elements (i.e., the third conductive element, the fourth conductive element, etc.). However, it should be understood that this may vary, and the conductive elements may be movable relative to each other in other ways, more or less, in a movable configuration.

[0212] Although one or more ropes 105, 107 are used as a driving device by which the electrodes 102, 104 are transformed from a movable configuration to a shape-fitting configuration, many other possible driving devices may also be used. For example, a spring and hinge system may be used to drive the conductive elements to engage with each other. Alternatively, an electromagnet system may be used, wherein the electromagnets are activated to attract adjacent conductive elements and pull them toward each other. However, the ropes 105, 107 provide a simple and convenient means of pulling the conductive elements to engage with each other in a reliable and repeatable manner. It should also be understood that the illustrated multiple ropes 105, 107 can be actuated simultaneously (e.g., in a single action, both ropes 105, 107 are tensioned).

[0213] Go to Figure 2b , provides an alternative perspective view of the electrode assembly 100, wherein the mounting body 106 is more clearly visible. Figure 2a As described, the electrode assembly 100 includes a first electrode 102 and a second electrode 104 ( Figure 2b The conductive elements are not marked).

[0214] Figure 2b The mounting body 106 is illustrated to include holes 134, 136, 138, 140, which are used to align the mounting body 106 with the component and / or to secure the mounting body 106 to the component. The mounting body 106 also includes an electrolyte orifice 142. As its name suggests, the electrolyte orifice 142 is incorporated for receiving or discharging electrolyte therethrough. That is, 'fresh' electrolyte can be introduced through the electrolyte orifice 142 to supply electrolyte for electrochemical machining. The electrolyte orifice 142 thus constitutes an electrolyte inlet. Alternatively, "spent" electrolyte after it has been used in the electrochemical machining process can be received through the electrolyte orifice 142. In this case, the electrolyte orifice 142 constitutes a discharge outlet.

[0215] Figure 2b The mounting body 106 is also shown to include two holes 144, 146 through which the cords 105, 107 are received. Figure 2b Not visible in the diagram, there are two additional holes, one associated with each electrode 102, 104, through which the other ends of the respective cords 105, 107 are received. For a given cord 105, 107, the holes are preferably generally opposite each other (e.g., one hole may be located near the 12 o'clock position and the other near the 6 o'clock position).

[0216] exist Figure 2bAlso shown are fasteners 148, 150 in the form of bolts that are used to secure the electrodes 102, 104 to the mounting body 106. It should be understood that each fastener 148, 150 is received through a corresponding hole in the mounting body 106.

[0217] Go to Figures 3a to 3e , the reference electrode 200 is now described Figure 2a and Figure 2b The electrode 200 includes six conductive elements 202, 204, 206, 208, 210, 212. The conductive elements are arranged in the same manner as the conductive elements described with respect to the previous figures. However, in the illustrated electrode 200, the conductive elements are relatively short. Figure 3a Also shown is an operator's hand 214, which is used to replicate the role of the mounting body in securing or pinning the first conductive element 202 in place. Also shown is a cord 216 having ends 218, 220. The cord 216 extends through each conductive element.

[0218] Figure 3a The electrode 200, and specifically the conductive elements thereof, is shown in a movable configuration. In the movable configuration, the conductive elements are able to move relative to each other. This facilitates the insertion of the electrode 200 into a cavity, and in particular into a non-linear cavity (e.g., a volute of a turbine machine housing). For example, the outermost conductive element 212 can pivot relative to the adjacent fifth conductive element 210. Similarly, the fifth conductive element 210 can pivot relative to the adjacent conductive element 208, and so on. Therefore, the electrode 200 has multiple degrees of freedom, meaning that the electrode 200 can be inserted into and extend through a non-linear cavity. It should be noted that although the term "pivot" is used above, this is due to the illustrated electrode 200 being disposed on a flat surface (thus limiting some degrees of freedom between the conductive elements). When the electrode 200 is effectively suspended within the cavity by the mounting body, it should be understood that the conductive elements have a greater number of degrees of freedom due to the presence of gaps above and below the conductive elements.

[0219] exist Figure 3a In the embodiment, the operator's hand 214 is used to hold the first conductive element 202. As previously described, the operator's hand 214 replicates the first conductive element 202 that is held by the mounting body (see FIG. Figure 2a and Figure 2b106) to the first conductive element 202. Thus, in use, and at the point where the first conductive element 202 is pinned in place, the mounting body has engaged the component (to be processed) and at least the first conductive element 202 is aligned within the component (specifically the cavity of the component). This alignment preferably takes the form of a gap or void that exists continuously around the exterior or outer surface of the first conductive element 202, between the exterior and the inner wall of the cavity. In other words, there is a gap extending around the exterior of the first conductive element 202 between the conductive element and the inner wall.

[0220] At the point where the first conductive element 202 is aligned and pinned in place (i.e., by use of a nail, fastener, toggle clamp or the like), the drive means (in this example, the cord 216) is then actuated to transform the electrode 200 into a form-fitting configuration. In the illustrated example, the actuation takes the form of a user applying tension to the ends 220, 218 of the cord 216. This may alternatively also be described as tensioning the cord 216. With the first conductive element 202 pinned in place, the tensioning cord 216 (it will be recalled that the cord 216 folds back on itself within the outermost conductive element 212) pulls the conductive elements into engagement with one another. In other words, the conductive elements become aligned with one another. This is accomplished by pulling the conductive element 202 from the outermost conductive element 212. Figure 3a (Electrode shown in movable configuration) Move to Figure 3b And to Figure 3c (The electrode 200 is shown in a form-fitting configuration).

[0221] Go to Figure 3b , showing the first stage of the transition of the electrode 200 from the movable configuration to the form-fitting configuration. Figure 5 b, upon (partially) tensioning the cord 216 and with the first conductive element 202 held in place, the conductive elements begin to move toward each other, toward a form-fitting configuration. Generally speaking, as long as the cord 216 extends through each conductive element and folds back on itself within the outermost conductive element 212, the outermost conductive element 212 is first pulled into alignment with the successive and adjacent fifth conductive element 210. This effect will generally continue between successive conductive elements until, as shown in FIG. Figure 3b As shown, the fourth conductive element 208 is generally aligned with the third conductive element 206 .

[0222] Since the rope 216 is Figure 3b200 is only partially tensioned, and the electrode 200 is only moved toward the form-fitting configuration, but not in the form-fitting configuration, so that gaps 222, 224 remain between the second conductive element 204 and the third conductive element 206 and between the first conductive element 202 and the second conductive element 204, respectively. These gaps 222, 224 indicate that the electrode 200 is not in the form-fitting configuration, because these conductive elements are not yet aligned with each other. Figure 3b and Figure 3a When compared, it can be appreciated that for conductive elements 206, 208, 210, 212 that are aligned with one another, gaps that previously existed or may have existed between the conductive elements have been removed from the conductive elements. Figure 3a Move to Figure 3b This can also be described as the conductive elements being pulled into engagement or alignment with each other. For these conductive elements, it should be understood that the respective outer surfaces of these conductive elements define a substantially continuous portion of the outer surface of the electrode 200.

[0223] Go to Figure 3c , as the rope 216 continues to be tensioned (from Figure 3b ), reached Figure 3c The shape fit configuration shown. By comparison Figure 3b and Figure 3c It can be understood that the gaps 222, 224 existing between the first conductive element 202, the second conductive element 204 and the third conductive element 206 are already Figure 3c is removed from the form-fitting configuration so that all the conductive elements are aligned with each other. Figure 3c In the embodiment, the outer surface of each constituent conductive element defines a substantially continuous outer electrode surface 201. Figure 3c The outer surface of each conductive element 202, 204, etc. is not individually labeled, but it is understood that the outer surface refers to Figure 5 c to Figure 5 The exterior of each corresponding conductive element is visible in e. Figure 3c The phase connection between the conductive elements can be seen in FIG. 226 . A phase connection between the fifth conductive element 210 and the outermost conductive element 212 is marked as 226 .

[0224] Go to Figure 3d , provides a rotated perspective view of the electrode 200 in a form-fitting configuration. Figure 3d The view of again shows that each conductive element is aligned with each other in a form-fitting configuration. More details about the outermost conductive elements 212 are shown below.

[0225] and Figure 2aSimilar to the outermost conductive element 116 of the electrode 200, the outermost conductive element 212 includes portions of passages 228, 230 extending through the conductive element of the electrode 200. The cord 216 is received through these passages 228, 230. The outermost portion 233 of the cord 216 is also Figure 3d 230 . As previously described, the rope 216 is folded back on itself through the outermost conductive element 212 (i.e., in a U-shaped manner). This is achieved by the passages 228, 230 leading to a single opening 234 near the outermost end of the outermost conductive element 212. The rope 216 extends through both passages 228, 230 and extends across a portion 236 of the material extending between and at least partially defining the passages 228, 230. It should be understood that when the rope 216 is tensioned, the engagement between the outermost portion 233 of the rope 216 and the portion 236 of the material effectively pulls all of the conductive elements into engagement with each other (usually sequentially). In other embodiments, a single pass of the rope may extend through only a single passage in each conductive element.

[0226] Go to Figure 3e , provides a view of the bottom side of the electrode 200 in a form-fitting configuration. Again, Figure 3e The view of FIG. 2 shows that the conductive elements are aligned with each other to define a substantially continuous outer electrode surface 201. Figure 3c , Figure 3d and Figure 3e It can be understood from the combination of each of the figures in that when the electrode 200 is arranged in a form-fitting configuration, the alignment features between the conductive elements are no longer visible. That is, the alignment features are generally obscured by the conductive elements, and specifically by their outer surfaces. The conductive elements can be described as being flush with each other in the form-fitting configuration.

[0227] The electrode 200 is shown as being fully arcuate in the form-fit configuration, but it should be understood that, for example, Figure 2a and Figure 2b In the embodiment, the electrodes can be a combination of substantially linear and non-linear (eg, arc-shaped) in a form-fitting configuration. By comparison Figure 3a and Figure 3c to Figure 3e It will be appreciated that the electrode 200 may be inserted into a non-linear cavity before being transformed into a form-fitting configuration so that the outer electrode surface more closely matches the inner wall of the cavity. This is particularly useful in the case where the cavity is a non-linear cavity, such as a volute of a turbine machine housing, facilitating electrochemical machining of the inner wall.

[0228] Go to Figure 4 , provides a cross-sectional view of the turbine housing 250 into which the electrode 102 is inserted.

[0229] For illustration purposes and ease of reference, only ( Figure 2a and Figure 2b 102 of the entire electrode assembly 100. The mounting body and the rope are omitted. It should also be understood that the electrode 102 is shown in a form-fitting configuration. Therefore, the conductive elements 108, 110, 112, 114, 116 are aligned with each other, specifically their outer surfaces are aligned with each other, so as to define a substantially continuous outer electrode surface 101. This will be described in more detail below.

[0230] Beginning first with the turbine housing 250, as is known in the art, the turbine housing 250 includes an inlet 252 and an outlet 254. The inlet 252 is in the form of a generally tangential opening 256. The inlet 252 and the opening 256 are defined in a flange 258 of the turbine housing 250. The inlet 252 is in fluid communication with the outlet 254.

[0231] The outlet 252 is a generally axial outlet. In use, the exhaust gas flow received through the inlet 252 is discharged through the outlet 254 after expansion through the turbine impeller. The outlet 254 can be defined in a generally tubular outlet portion of the turbine housing 250. The turbine impeller (not shown) rotates about the axis 225. The turbine impeller is disposed in the fluid path between the inlet 252 and the outlet 254.

[0232] Extending at least partially between the inlet 252 and the outlet 254 is a cavity in the form of a volute 260. The volute 260 has a generally helical geometry. That is, the radial position of the cross-sectional profile of the volute 260 varies relative to the axis of rotation 225. The volute 260 can be described as having a generally linear portion or extension 264 and having a generally non-linear portion beyond the linear portion 264. Figure 4 It will be appreciated that the cross-sectional profile of the volute 260 varies along the extent of the volute. The cross-sectional profile of the volute also generally decreases in area and changes in shape when moving from the inlet 252 to the outlet 254. The volute 260 can be described as being defined by an inner wall 268.

[0233] Return to Figure 4 , the volute 260 includes an outer end or tip 266. Although Figure 4 254 , but the outer end 266 of the volute 260 is in fluid communication with the outlet 254 through the nozzle or throat of the turbine housing 250 . In other words, the volute 260 opens into the outlet 254 .

[0234] from Figure 4As can be appreciated, the volute 260 is a challenging geometry. Typically, a turbine housing is cast using a mold using processes such as sand casting and investment casting to define the cavity of the volute 260 in the turbine housing. However, such processes may not provide the desired surface finish, particularly in applications where the surface finish may have a significant impact on the efficiency of fluid flow therethrough. Advantageously, by utilizing the electrode assembly 100 described herein, an electrochemical machining process may be used to machine or polish to define the inner wall 268 of the volute 260. Furthermore, this may occur along most or the entire extension or length of the volute 260 (i.e., between the opening 256 and the outer end 266).

[0235] Now about Figure 4 Methods of using the electrode assembly 100 are described. It should be remembered that some features of the electrode assembly 100 are not described in Figure 4 Shown in.

[0236] First, the outermost conductive element 116 of the electrode 102 is inserted through the opening 256 of the inlet 252. The electrode 102 is inserted in a movable configuration, whereby the conductive elements 108, 110, 112, 114, 116 can move relative to each other. The electrode 102 is inserted along the extension of the volute 260 until a portion of the electrode 102 contacts the inner wall 268 of the volute 260. For completeness, it should be understood that the inner wall 268 extends along the entire extension of the volute 260. That is, a portion of the inner wall 268 will define, for example, the outer end 266 of the volute 260. Because the electrode 102 is inserted in a movable configuration, the contact between the conductive element (e.g., the outermost end 117 of the outermost conductive element 116) and the inner wall 268 causes the conductive element to move somewhat so as to better fit the volute 260 in a form. The electrode 102 is said to be deflected by the inner wall 268. This effectively allows the electrode 102 to follow the non-linear path of the volute 260 (e.g., downstream of the linear portion 264 of the volute 260). Insertion (of the electrode 102) continues until the mounting body of the electrode assembly engages the flange 258 of the turbine housing 250. At this point, the mounting body is coupled to the flange 258, optionally with a gasket between the mounting body and the flange 258, to align the electrode 102 within the volute 260. The alignment is with reference to aligning the electrode 102 relative to the cross-sectional profile of the volute 260 such that a gap exists around at least the outer surface of the first conductive element 108 and the facing portion of the inner wall 268 of the volute 260. Figure 4 An example of this is shown where a gap 270 is provided around the outer surface of the electrode 102 .

[0237] Then, the actuating device (e.g., a rope) is actuated to transform the electrode 102 from the movable configuration to the form-fitting configuration. Actuating the actuating device (e.g., tensioning the rope) pulls the conductive elements into engagement with each other so that the respective outer surfaces of the conductive elements define a substantially continuous outer electrode surface. In other words, by pulling the conductive elements into engagement with each other, any gaps that previously existed between the conductive elements are substantially removed. This actuation effectively means that the second conductive element 110 and subsequent conductive elements (e.g., the third conductive element 110, the fourth conductive element 112) are aligned within the volute 260 by virtue of the alignment between the mounting body and the flange 258. Along the extension of the volute 260 that the electrode 102 reaches or occupies (i.e., until Figure 4 A continuous gap is provided around the electrode 102 at a position near the outer end 117 of the electrode 102.

[0238] A negative charge is then applied to the electrode 102, and a flow of electrolyte is pumped through the volute 260 to begin the electrochemical machining process. The power supply to which the electrode 102 is connected can provide approximately 1.5 kA at approximately 40 V (i.e., a 60 kW power supply). The power supply can provide approximately 2.5 kA at approximately 40 V (i.e., a 100 kW power supply). The machining process removes material from the inner wall 268 of the volute 260. This process can be effective for improving the surface finish (e.g., reducing surface roughness) and / or improving the manufacturing tolerances of the volute 260 (e.g., the dimensions of the volute 260). The turbine housing 250 is also grounded, which then effectively applies a positive charge to the turbine housing 250 relative to the negatively charged electrode 102. However, in other embodiments, the turbine housing 250 can be electrically coupled to the positive terminal of the power supply in other ways. What then occurs is Figure 1 Describe the process.

[0239] Specifically, the electrode 102 (specifically the conductive element 108 and later conductive elements) forms the cathode, and the inner wall 268 of the volute 260 forms the anode. The gap between the outer surface of the electrode 102 and the inner wall 268 reduces the risk of arcing or shorting between the electrode 102 and the inner wall 136 (which would otherwise cause poor surface finish and other problems during processing). The electrolyte flow effectively completes the circuit, and as electrons pass through the electrolyte and are absorbed by the inner wall 136, material is removed or evaporated from the inner wall 268. The electrolyte flow further transports any removed material and discharges the waste material through the corresponding outlet. It should be understood that the electrolyte flow can be pumped through the inlet 252 in a direction toward the outlet 254, or can be pumped into the outlet 254 and discharged through the inlet 252. Either way, the electrolyte can be discharged through the inlet 252. Figure 2b Electrolyte orifice 142 is shown.

[0240] Once electrochemical machining has occurred, the actuating device can then be released so that the electrode 102 can be transformed into a movable configuration. The mounting body can then be disengaged from the flange 258 and the assembly withdrawn from the volute 260. In a manner similar to the manner in which the conductive element is form-fitted with the volute 260 when inserted, during removal or withdrawal of the electrode 102, when the conductive element contacts the inner wall 268, the electrode 102 can effectively move to better form-fit the geometry of the volute 260, thereby facilitating the removal of the electrode 102. In other words, the electrode 102 is deflected by contact with the inner wall 268 to facilitate removal of the electrode 102 and prevent the electrode 102 from being stuck in the volute 260.

[0241] The electrolyte may be salt water or any other fluid that provides an ion flow (optionally, with multiple bodies entrained therein). A weakly acidic solution is another example of a suitable electrolyte. The electrolyte may include sodium nitrate and / or sodium chloride. The electrolyte may include a liquid electrolyte (or consist of a liquid electrolyte). The electrolyte may contain multiple bodies (e.g., solid bodies), which may be conductive or non-conductive. The multiple bodies may be entrained in (e.g., suspended in) a medium such as a liquid or a gas. The medium may be conductive or non-conductive. Alternatively, the electrolyte may consist of multiple (conductive) bodies (e.g., solid media) isolated from the fluid electrolyte. An example of multiple bodies is a solid medium, which may be conductive or non-conductive. Multiple bodies may include beads (e.g., spherical particles) and / or non-spherical particles. Thus, multiple bodies (e.g., solid media) optionally suspended in a medium may provide an electrolyte for use according to the present invention.

[0242] For completeness, although Figure 4 Only a single volute 260 is shown in the turbine housing 250, but the turbine housing 250 can be a double-inlet turbine housing. That is, the turbine housing 250 includes a pair of volutes. The volutes generally follow the same profile. The electrode assembly illustrated in the previous figures is particularly advantageous for this double volute arrangement, in which one electrode is received in each of the two volutes. Therefore, the volutes can be machined simultaneously and using a single electrolyte supply. However, it should also be understood that a turbine housing including only a single volute can also be machined using electrochemical machining. In such an example, the electrode assembly can also include only one electrode.

[0243] Although described above with reference to a turbine casing volute, it will be appreciated that there is a range of other components, and cavities therein, which may be advantageously machined using the electrochemical machining processes and electrode assemblies described herein. One such alternative is a compressor casing volute having a similar Figure 4The turbine housing volute shown in FIG. 1 has a generally similar geometry to that of the turbine housing volute shown in FIG. 1 , but there are some geometric differences (e.g., the cross-section of the volute is generally circular and preferably varies in area in a linear manner). Other components include valves, manifolds (e.g., exhaust manifolds), and any other components having a relatively complex cavity. Examples of relatively complex cavities include cavities that follow at least partially nonlinear paths, such as cavities that are at least partially arcuate. Other examples of relatively complex cavities include cavities having a staggered or dog-leg arrangement. The cavity may have a generally tubular structure.

[0244] For completeness, Figure 4 Also shown is a portion of a passage 152 of the first conductive element 108 for receiving a cord therein. This portion of the passage 152 is visible, and the other passage is not visible because the passage extends through the first conductive element 108 in a non-linear manner (see Figure 3a and Figure 3b ).

[0245] As part of ongoing research and development of the above-described electrochemical machining method and apparatus, as well as other apparatus (as described in more detail later herein), the inventors have proposed a number of improvements to the method and apparatus. These developments relate to the distribution / uniformity of the electrolyte flow around the electrodes, which has been found to have a significant impact on the quality of the electrochemical machining. These developments also relate to pre-charging the electrodes with electrolyte before reaching the above-described electrode(s).

[0246] The inventors have implemented the above developments by modifying the mounting body, as described in detail below.

[0247] Go to Figure 5 , provides a perspective view of a mounting body 300 according to an embodiment of the present invention. The mounting body 300 shares many features in common with previously described mounting bodies, and therefore only the differences are described in detail.

[0248] The mounting body 300 comprises an integral first conductive element 302. In other words, the mounting body 300 and the first conductive element 302 are essentially unitary and are manufactured as a single component. This has been found to be particularly advantageous in ensuring accurate alignment of the entire electrode (of which the first conductive element 302 forms a part) within the cavity to be machined. At the second end 304 of the first conductive element 302 there is a protrusion 306 (similar to the protrusion 306 described with respect to FIG. 1 ). Fig. 20 As described above, the second end portion 304 is generally distal to the engagement surface 705 of the mounting body 300 .

[0249] The mounting body 300 includes four holes 308, 310, 312 (the fourth hole is Figure 5 The four holes are hidden from view) and are used to align the mounting body 300 with the component to be processed.

[0250] The mounting body 300 also includes an integral bus bar 314. The bus bar 314 is integral in that both the mounting body 300 and the bus bar 314 are a single component. The bus bar 314 actually refers to an additional piece of material, and in the illustrated embodiment, the bus bar 314 includes an array 316 of additional holes. In the illustrated embodiment, the array 316 includes ten holes. The constituent holes of the array 316 serve as sockets into which the power supply cable is inserted in use. Thus, the power supply is arranged to be electrically connected to the electrode through the mounting body 300, wherein the first conductive element 302 forms a part of the electrode. In use, a conductive insert (e.g., a copper or stainless steel insert) can be inserted into the holes that make up the array of holes 316. Advantageously, the integral bus bar 314 reduces the voltage drop between the mounting body and the conductive elements of the electrode. This is achieved by effectively removing the interface (e.g., an electrical connection point) that would otherwise exist between the bus bar and (e.g.) the electrode. The efficiency of the entire electrochemical machining process is thereby improved. For completeness, each interface (e.g., between adjacent conductive elements) may result in a corresponding voltage drop of, for example, about 2V to 3V. For a 30V power supply, the voltage drop at each interface may represent ~10% of the supply voltage. Furthermore, each interface is a potential point of failure. Therefore, it is desirable to minimize the number of interfaces or connections.

[0251] The mounting body 300 also includes an electrolyte orifice 318. In the illustrated embodiment, the electrolyte orifice 318 is configured to receive electrolyte therethrough. The electrolyte orifice 318 extends partially through the mounting body 300. A connecting passage 320 formed within the mounting body 300 is disposed downstream of the electrolyte orifice 318. The combination of the electrolyte orifice 318 and the connecting passage 320 can be said to define an elbow insofar as the direction of the electrolyte changes by substantially 90° as it passes through the elbow. Although in the embodiment of FIG. Figure 5 302 , but will be described in detail with respect to later figures, the connecting channel 320 leads to an internal cavity within the first conductive element 302. An array of electrolyte channels 322 (which may be referred to as exhaust channels) are distributed around the first conductive element 302. Specifically, the electrolyte channels 322 extend through the first conductive element 302 (i.e., from the internal cavity to the outer surface). In a preferred embodiment, at least the downstream ends of the electrolyte channels 322 are distributed around the electrode. More details about the electrolyte channels will be provided in later figures. The downstream ends of the electrolyte channels 322 extend only partially around the conductive element 302 (e.g., distributed around a portion of the periphery of the conductive element).

[0252] It should be appreciated that the distribution of the electrolyte channels 322 facilitates the isolation and combination of the integral bus bar 314 and the integral first conductive element 302. The advantages associated with the distribution of the electrolyte channels 322 may be applicable to a wider range of electrodes than the hinged electrodes shown in the illustrated example (as will be described in detail below).

[0253] The mounting body 300 is preferably manufactured using an additive manufacturing method.

[0254] Go to Figure 6a and Figure 6b , illustrates a perspective view of a mounting body 330 according to another embodiment. Figure 6a The mounting body 330 is shown from the side of the engagement surface 331 of the mounting body 330 (eg, close to the cavity to be processed). Figure 6b A generally opposite side (eg, rear side) of the mounting body 330 is shown.

[0255] The mounting body 330 shares Figure 5 The illustrated mounting bodies 300 share many features. Therefore, only the differences will be described in detail.

[0256] The mounting body 330 comprises a plurality of (integral) first conductive elements 332, 334. The mounting body 330 does not contain an integral bus bar.

[0257] Figure 6b Two additional holes 336, 338 are shown in the rear face 335 of the mounting body 330. The holes 336, 338 are configured to receive respective ropes therethrough so that when the ropes are tensioned, the downstream conductive elements are pulled into alignment with each other (e.g., the electrodes are transformed into a form-fitting configuration). The holes 336, 338 may receive glands in use through which the ropes are received.

[0258] The mounting body 330 also includes an electrolyte port 340 .

[0259] Figure 6a Two arrays 342, 344 of electrolyte channels are shown distributed around the periphery of respective first conductive elements 332, 334. As previously described, in use, electrolyte is drained or expelled through the electrolyte channels around the outer electrode surface of the electrode.

[0260] Go to Figure 6c and Figure 6d , a perspective cutaway view of the mounting body 330 is provided. Figure 6c is along Figure 6a The cross section marked as 346 is taken from Figure 6d is along Figure 6b The cross section marked 348 is taken.

[0261] from Figure 6c Start, such as Figure 6a As indicated, the cross section is taken along the thickness of the mounting body 330 . Figure 6c The electrolyte orifice 340 is shown extending partially through the mounting body 330 and splitting into two connecting channels 350, 352. The downstream end of each of the first connecting channel 350 and the second connecting channel 352 opens into a respective first conductive element cavity 354, 356. The cavity 354, 356 refers to the internal volume within each of the first conductive elements 332, 334, respectively. Figure 6d It will be appreciated that the cavities 354, 356 extend partially through the first conductive elements 332, 334, respectively. The cavities 354, 356 advantageously reduce the mass of the mounting body 330 and provide a fluid path for electrolyte to flow therethrough.

[0262] Return to Figure 6c , the electrolyte channels of the first array 342 and the second array 344 extend between the cavities 354, 356 and the outer surfaces of the first conductive elements 332, 334. When the mounting body 330 is coupled to the component to be processed and the electrode(s) extend through the cavity to be processed, the electrolyte is pumped through the electrolyte orifice 340, through one of the first connection channel 350 and the second connection channel 352 into the corresponding conductive element cavity 354, 356, and then discharged by the electrolyte channels of the corresponding array 342, 344. The electrolyte is discharged into the gap between the inner wall of the cavity to be processed and the outer electrode surface of the electrode (e.g., including the first conductive elements 332, 334) through the electrolyte channels in the arrays 342, 344.

[0263] Go to Figure 6d , the layout of the electrolyte channels will now be described in more detail. Figure 6d The electrolyte channels of the first array 342 are shown to include electrolyte channels arranged substantially on two opposite sides of the perimeter of the first conductive element 332. In other words, Figure 6d As shown, electrolyte pathways are provided only through substantially upper and lower sides of the first conductive element 332. Where the first conductive element 332 has a substantially rectangular cross-section, the electrolyte pathways may be described as being provided only along a pair of parallel sides.

[0264] Beginning with the electrolyte channels of the first array 342, the first array 342 includes a first series 358 and a second series 360 of electrolyte channels. The electrolyte channels of the first series 358 and the second series 360 are disposed on opposite sides of the first conductive element 332, while the other pair of opposite sides have no electrolyte channels. In other words, two of the two sides are substantially solid, without channels, while two of the two sides do include channels. The two electrolyte channels are labeled 362, 364, respectively, and form a portion of the first series 358 and the second series 360 of electrolyte channels, respectively. Each electrolyte channel extends generally normally through the thickness of the first conductive element 332 (i.e., through the inner and outer surfaces of the conductive element 332 at right angles).

[0265] Advantageously, the inventors have found that providing a distribution of electrolyte channels around the electrode provides an improved distribution of electrolyte flow around the electrode during electrochemical machining. This in turn improves electrochemical machining efficiency by more evenly removing material from the internal cavity being machined.

[0266] Although not described in detail herein, the other first conductive element 334 also includes electrolyte channels in an array 344, including first and second series disposed substantially on opposite sides of the first conductive element 334. The above description regarding array 342 applies equally to array 344.

[0267] Wherever the electrolyte flows through: 1) a channel or conduit of the mounting body that is electrically connected to at least a portion of the electrode (e.g., where the first conductive element is integral to the mounting body); and 2) a channel or conduit located upstream of the electrode (e.g., the first conductive element of the electrode), the electrolyte is effectively pre-charged before it encounters the electrode. In other words, the ions within the electrolyte become charged. This is advantageous, for reasons that will be described in detail later herein, because the processing action of the electrolyte more effectively occurs at the upstream end of the cavity to be processed.

[0268] Go to Figure 7 , which illustrates a cross-sectional view of another embodiment of the mounting body 370. The mounting body 370 shares the Figure 5 The mounting body 300 and Fig.23 a to Fig.23 d share many features with the mounting body 330. Only the differences are described in detail.

[0269] The mounting body 370 includes an integral first conductive element 372 and a second conductive element 374. In addition, the mounting body 370 includes an integral bus bar 376.

[0270] Unlike the previous embodiments, the electrolyte channel is not arranged perpendicular to the thickness of the first conductive elements 372, 374, but at an angle (e.g., inclined). Therefore, the electrolyte channel can guide the electrolyte more smoothly in the direction along which the cavity to be processed extends. In other words, the electrolyte channel guides the electrolyte to flow around and along the first conductive elements 372, 374. In the illustrated embodiment, and taking the first electrolyte channel 38378 as an example, the electrolyte channel is angled in the downstream direction. That is, the electrolyte channel is angled with the flow direction through the cavities 379, 381 and into the internal cavity to be processed. The electrolyte channel 38378 can be said to define an axis 383, and the axis 383 defines an angle 385 with the joint surface 380 of the mounting body 370. Angle 385 is preferably an acute angle. In the illustrated embodiment, angle 385 is about 45 degrees. The electrolyte flow through various channels and cavities also provides a favorable cooling effect on the electrode.

[0271] The electrolyte channels of the mounting body 370 are provided only along two opposing sides of each of the first conductive elements 332, 334. The other two sides remain solid and do not contain any electrolyte channels. In the illustrated embodiment, the electrolyte channels are holes (i.e., circular in cross-section and straight in extent), but in other embodiments, other geometries and / or shapes may be employed.

[0272] Go to Figure 8 , provides a perspective view of a portion of a mounting body 390 according to another embodiment. The mounting body 390 shares the Figure 7 The illustrated mounting bodies 370 share many features, and only the differences are described in detail.

[0273] The first conductive elements 392, 394 are integral with the mounting body 390, as are bus bars. The electrolyte channels of the first array 396 and the second array 398 extend around the perimeter of each of the first conductive elements 392, 394, respectively. Figure 7Unlike the illustrated mounting body 370, for the mounting body 390, each of the arrays 396, 398 of electrolyte channels extends continuously around the perimeter of the first conductive element 392, 394. In other words, the electrolyte channels are provided through each side of the conductive element 392, 394 (i.e., the conductive element 392, 394 has no side that does not have an electrolyte channel). The distribution of the electrolyte channels can be described as an equidistant distribution around the (entire) perimeter of the conductive element 392, 394, wherein the electrolyte channels define a generally repeating pattern with equidistant spacing between adjacent electrolyte channels. This is generally true except for any minor deviations to allow the driving device (i.e., the flexible element, such as a rope) to extend through the conductive element 392, 394. In other words, the repeating pattern or uniform distribution may not be perfectly uniform or equal for each electrolyte channel, and there may be minor deviations.

[0274] Go to Fig. 9 , providing support for Figure 7 Results of computational fluid dynamics (CFD) simulation of the electrode assembly 371 of the mounting body 370 . Fig. 9 3 is a velocity diagram showing the profile and velocity of electrolyte passing through the mounting body 370 and along the first electrode 373 and the second electrode 375 of which the first conductive elements 372, 374 form a part. Fig. 9 The view of FIG. 1 hides the turbine housing into which the first electrode 373 and the second electrode 375 are inserted. Similarly, a pair of turbine housing volutes (which are cavities machined by electrochemical machining) are also hidden from view. For completeness, FIG. Fig.11 Representative shells are indicated in .

[0275] Back to Fig. 9 The electrode assembly 371, in particular the mounting body 370 of the ground electrode assembly, includes an electrolyte conduit 37377. In use, electrolyte is supplied to the mounting body 370 through the electrolyte conduit 37377. Fig. 9 It will be appreciated that the electrolyte conduit 37377 is generally disposed at a right angle to the thickness of the mounting body 370 (eg, an elbow joint).

[0276] Fig. 9 The CFD results shown indicate that there are regions 382, ​​384 of relatively high recirculation of electrolyte near the downstream end of the electrolyte channel (i.e., near where the electrolyte first exits the mounting body 370 through the first conductive element 372, 374). Specifically, the high recirculation regions 382, ​​384 occur on the sides of the conductive elements 372, 374 that do not contain any electrolyte channels. Fig. 9374, but similar results are observed on opposite sides of the first conductive elements 372, 374. Similarly, it can be understood from the velocity graph that the flow velocity of the electrolyte is relatively low around the first electrode 373 compared to the second electrode 375. In other words, the electrolyte generally moves at a higher velocity around the lower electrode compared to the upper electrode.

[0277] It has been found that regions of recirculating electrolyte are undesirable, at least because the continuous flow of fresh electrolyte along the electrodes 373, 375 results in the most efficient and uniform electrochemical machining. When electrochemical machining occurs, insulating hydroxides are formed as a byproduct of the process (e.g., in the form of a viscous slurry). As described above, the insulating properties of the hydroxides, in areas where the inner walls of the cavity are effectively shielded by these insulating hydroxides, can negatively affect electrochemical machining by reducing the efficiency of the machining or even preventing machining altogether. During normal operation, these hydroxides are flushed away by continuously pumping electrolyte through the cavity being machined. Electrolyte flow recirculation regions 382, ​​384 can cause regions of the interior cavity to be machined at a significantly lower rate than other regions (i.e., the difference can be up to three times the magnitude of the machining). This is at least in part due to the hydroxides being suspended by the electrolyte rather than being "flushed away". More generally, turbulence in the electrolyte flow is undesirable.

[0278] Go to Fig.10 , provides the results of CFD simulations performed on a modified electrode assembly 371a. The modified electrode assembly 371a shares the same Fig. 9 In other words, the electrolyte conduit 379 does not extend generally normal to the thickness of the mounting body 370a, but rather extends generally normal to the major faces (ie, the mating face and the opposing face) of the mounting body 370a.

[0279] Due to the difference in orientation of the electrolyte conduit 379, Fig. 9 Compared with the substantially right-angled electrolyte conduits 37377 in FIG. 26 , the electrolyte supplied through the electrolyte conduit 379 has fewer and less drastic changes in direction. When comparing the CFD results of FIG. 26 and FIG. 27 , it can be understood that in Fig.10 In the embodiment, the flow is more evenly distributed around the conductive elements 372, 374, and Fig. 9 The recirculation zones 382, ​​384 have been reduced. However, some recirculation remains in a similar zone at the sides of the conductive elements 372, 374 where there are no electrolyte channels. In short, including a substantially straight supply electrolyte conduit 379 has improved flow characteristics and will therefore improve the efficiency of electrochemical machining, but it is still desirable to obtain a more uniform flow distribution around the conductive elements 372, 374 of each respective electrode.

[0280] Fig.11 Shown are the Figure 8 Results of CFD simulations performed on electrode assembly 371 b of mounting body 390 (eg, where the downstream ends of the electrolyte channels are substantially uniformly and continuously distributed around the electrode).

[0281] When compared Fig. 9 and Fig.11 When, it will be appreciated that distributing the downstream ends of the electrolyte channels around the entire perimeter of the electrode(s) (eg, substantially evenly) will reduce recirculation of electrolyte within the cavity being processed.

[0282] Fig.12a is a perspective view of an electrode assembly 400 according to another embodiment.

[0283] The electrode assembly 400 includes a mounting body 402 , a first electrode 404 , and an electrolyte conduit 406 .

[0284] As previously described elsewhere herein, the first electrode 404 includes a first conductive element 408, a second conductive element 410, and a third conductive element 412. The conductive elements 408, 410, 412 are hingedly connected to each other. For the avoidance of doubt, the electrode 404 is shown in a movable configuration in which the conductive elements 408, 410, 412 are movable relative to each other, but the electrode 404 can be converted into a form-fitting configuration in which the conductive elements 408, 410, 412 are aligned with each other to define a substantially continuous outer electrode surface. The first conductive element 408 is coupled to the mounting body 402 and is integral with the mounting body 402. The mounting body 402 also includes an integral bus bar 414.

[0285] A plurality of electrolyte channels are provided through the mounting body 402 through which electrolyte can flow, and these electrolyte channels can be referred to as discharge channels. The first to fourth electrolyte channels 416, 418, 420, 422 are distributed around the first conductive element 408 of the electrode 404. The plurality of electrolyte channels 416, 418, 420, 422 can be referred to as an array of electrolyte channels. The electrolyte channels are defined by ribs 424, 426, 430 ( Fig.12a The ribs may be described as extending between the electrolyte channels 416, 418, 420, 422. More details about the electrolyte channels will be provided in conjunction with Fig.12c To provide, Fig.12c A cross-sectional view of an electrode assembly 400 is shown.

[0286] The mounting body 802 is preferably manufactured using an additive manufacturing method.

[0287] Figure 12bis a perspective view of the electrode assembly 400 viewed from generally the rear side of the assembly. Figure 12b The electrolyte conduit 406 is shown extending from the rear face 432 of the mounting body 402. In the illustrated embodiment, the electrolyte conduit 406 extends substantially perpendicular to the rear face 432 of the mounting body 402. In other words, the electrolyte conduit 406 is substantially normal to the rear face 432 of the mounting body 402. The electrolyte conduit 406 is an external conduit due to the fact that it protrudes from the rear face 432 of the mounting body 402 (rather than, for example, extending inside the mounting body 402). In the illustrated embodiment, the electrolyte conduit 406 has a circular cross-section, but it should be understood that other cross-sectional geometries may also be used in other ways. In the illustrated embodiment, the electrolyte conduit 406 is made of the same material as the rest of the mounting body 402 (e.g., 316L stainless steel, but other materials may also be used). The electrolyte conduit 406 is also integral with the mounting body 402. In other words, the electrolyte conduit 406 may be made in an integral manner with the rest of the mounting body 402 (i.e., such that they form a single component with no phase connections). Otherwise, and still considered integral, the electrolyte conduit 406 may be connected to the mounting body 402 in a subsequent manufacturing step (eg, welding). In the illustrated embodiment, the electrolyte conduit 406 is TIG welded to the mounting body 402 (specifically, the rear face 432 of the mounting body 402).

[0288] The electrolyte conduit 406 preferably extends at least one diameter, more preferably three diameters, and more preferably at least six diameters (e.g., Fig.12c 843 in ). Here, “extension” refers to the length of the electrolyte conduit 406. In the case where the electrolyte conduit 406 has a non-circular cross-section, the extension of the conduit can be defined based on the main dimension of the cross-section through the conduit (e.g., the diameter in the case of a circular tube).

[0289] Including the electrolyte conduit 406 provides a number of advantages. First, the electrolyte conduit 406 provides a heat sink function by increasing the surface area of ​​the conductive material that is in thermal communication with the majority of the rest of the mounting body 402. In this way, during electrochemical machining, for example, 1000A can pass through the mounting body 402 through the bus bar 414, and the electrolyte conduit 406 helps provide a heat sink function to cool the entire electrode assembly 400 and the electrolyte flowing therethrough. Another advantage is that the electrolyte conduit 406 provides a more uniform electrolyte flow through the mounting body 402 and around the first conductive element 408. As already described, uniform flow of electrolyte and reduced turbulence are desirable for reasons of improved efficiency of electrochemical machining. This is particularly advantageous in the case where the electrolyte conduit 406 is axial in nature (i.e., straight) and is substantially normal to the rear surface 432 of the mounting body 402. Another advantage provided by the electrolyte conduit 406 is that as the electrolyte flows through the conduit 406, because the electrolyte conduit 406 is electrically connected (e.g., because it is integral with the mounting body 402), the electrolyte is effectively charged as it flows through the conduit. Thus, the electrolyte conduit 406 can be considered to form part of an integral cathode of which the mounting body 402 forms part (including the integral bus bar 414 and the first conductive element 402). Thus, the charge is transferred to the electrolyte and the electrolyte is pre-charged before actually encountering the first conductive element 408 (e.g., before the electrolyte flow enters the electrolyte channels 416, 418, 420, 422). This has been found to be beneficial in improving the quality of the process because the electrolyte conduit 406 surrounding the first conductive element 408 (in the electrolyte channels) is electrically connected to the first conductive element 408. Fig.12a Precharging is accomplished by increasing the contact time of the electrolyte with the surrounding surfaces being charged.

[0290] For at least the reasons discussed above, the inclusion of the electrolyte conduit 406 provides a number of different benefits to the mounting body 402 and the electrode assembly 400 more generally.

[0291] Also shown is a hole 834 extending partially through the mounting body 402. The hole 834 is configured to receive an actuating device in the form of a flexible element (e.g., a rope) therethrough so as to be able to move the electrode 404 from a movable configuration (e.g., such as Figure 12b ) into a form-fitting configuration (e.g., Fig.21 as shown).

[0292] There is a gap or space 819 between the perimeter 821 of the first conductive element 408 and the outer edge 823 of the electrolyte channel. The gap is preferably between about 4 mm and about 6 mm. The outer edge 823 of the electrolyte channel preferably matches the opening defining the internal cavity to be processed.

[0293] Go to Fig.12c, provides Fig.12a and Figure 12b 4 is a perspective cross-sectional view of a portion of an electrode assembly 400 shown in FIG. Fig.12c The view is along Figure 12b The cross section marked 836 is taken.

[0294] First, starting with the electrolyte conduit 406, as mentioned in the illustrated embodiment above, the electrolyte conduit 406 is a circular tube with a circular cross-section. Therefore, in the illustrated embodiment, the main dimension of the cross-section of the electrolyte conduit 406 is defined by the diameter 440. Specifically, the main dimension is defined by the inner diameter 440. The electrolyte conduit 406 has an extension or length 843 (which is parallel to the axis 442 in the illustrated embodiment). In the illustrated embodiment, the extension 843 of the conduit 406 spans from the upstream end 438 to the upstream end 429 of the electrolyte channels 16, 418, 420, 422. As described above, in the illustrated embodiment, the extension 843 of the electrolyte conduit 406 is completely axial (i.e., straight), but in other embodiments, it may include an arc segment. Similarly, the axis 442 is perpendicular to the rear face 432 of the mounting body 402 and the engagement face 433. The axis 442 is also normal to the opening of the internal cavity machined by the electrochemical machining process.

[0295] In use, electrolyte is supplied through the electrolyte conduit 406 from the upstream end 438. The electrolyte then flows through the electrolyte conduit 406 as indicated by the directional arrow 444. Importantly, due to the axial nature of the dielectric conduit 406 and the orientation of the conduit 406 relative to the rear face 432 of the mounting body 402, the electrolyte flow 404 through the conduit 406 is relatively uniform and laminar.

[0296] At the downstream end of the electrolyte conduit 406, the flow of electrolyte 444 is then divided between a plurality of electrolyte channels 416, 418, 420, 422. The first electrolyte channel 416 and the second electrolyte channel 418 are shown in cross-section, with the third channel 420 and the fourth channel 422 partially obscured (although the upstream end is partially visible). Fig.12c As shown, each electrolyte channel 416, 418, 420, 422 is defined by one or more of the plurality of ribs 424, 426, 428, 430. For example, the first electrolyte channel 416 (in Fig.12c420, 422). The upper left quadrant of FIG. 4 is defined by a combination of a first rib 424 and a fourth rib 430. Each of the first to fourth ribs 424, 426, 428, 430 has a reduced cross-sectional area at the upstream end. In other words, each rib 424, 426, 428, 430 can be said to be tapered (e.g., beveled). Advantageously, this improves the guidance of electrolyte flow on the ribs 424, 426, 428, 430 and through the electrolyte channels 416, 418, 420, 422.

[0297] Electrolyte is delivered to the upstream end 438 of the electrolyte conduit 406 by another electrolyte supply (not shown). The electrolyte supply may be in the form of a conduit, preferably a non-conductive (eg, insulated) conduit.

[0298] When the general Fig.12c and Fig.12a When considered together, it should be understood that the electrolyte channels 416, 418, 420, 422 take the form of a generally arcuate cavity, particularly at the downstream end (e.g., 431) of the electrolyte channels. The arcuate cavity can also be described as an arcuate orifice at the downstream end 431 of the electrolyte channels 416, 418, 420, 422. In addition, the electrolyte channels 416, 418, 420, 422 (more specifically again the downstream end 431 thereof) are distributed around the first conductive element 408 and are generally shaped to fit the perimeter of the first conductive element 408. The electrolyte channels 416, 418, 420, 422 are also uniformly distributed around the entire perimeter of the first conductive element 408. The electrolyte channels 416, 418, 420, 422 also generally increase in cross-sectional area from the upstream end 429 to the downstream end 431, so that the electrolyte flow through the electrolyte channels can be described as diffuse.

[0299] Return to Fig.12c It should also be understood that the first conductive element 408 is coupled to each of the plurality of ribs 424, 426, 428, 430-432. In other words, the first conductive element 408 is effectively connected to the mounting body 402 through the ribs 424, 426, 428, 430-432. Furthermore, as previously described, the first conductive element 408 is integral with the mounting body 402.

[0300] Although there are four electrolyte channels 416, 418, 420, 422 in the illustrated embodiment, it should be understood that there may be more or fewer electrolyte channels. For example, two or three electrolyte channels may be included in other ways. Similarly, five or more electrolyte channels may be used in other ways. In addition, and returning to Fig.12a, the electrolyte channels 416, 418, 420, 422 are evenly distributed around the entire perimeter of the first conductive element 408. In other embodiments, the electrolyte channels 416, 418, 420, 422 may be distributed around only a portion of the perimeter of the electrode, and / or may extend through a portion of the electrode (e.g., Fig. 22 to Figure 25).

[0301] In the illustrated embodiment, each electrolyte channel 416, 418, 420, 422 extends completely through the main block of the mounting body 402 (e.g., between the engagement surface 433 and the rear face 432). In other embodiments, the electrolyte channels may not extend through this extent of the mounting body 402. However, it is preferred that the downstream end 431 of the plurality of electrolyte channels 416, 418, 420, 422 open outwardly through the engagement surface 433 of the mounting body 402.

[0302] at last, Fig.12c Also shown is a portion of a passage 444 through which an actuating device in the form of a flexible element (eg, a cord) extends through the electrode 404. Fig.12c 834 (eg, first rib 424) and through the aperture 834. Figure 12b as shown).

[0303] Go to Fig.13 and Fig.14 , showing the Figures 12a to 12c The results of CFD simulations of the electrode assembly 400 are shown in FIG. The results show that the electrolyte is discharged from the mounting body 402 to the part to be processed (in this case, the turbine housing 446, as shown in FIG. Fig.13 The speed profile of the path taken by Fig.13 and Fig.14 and Fig. 9 and Fig.10 When making comparisons, it is understandable that Fig. 9 and Fig.10The electrolyte is discharged from the mounting body in a more uniform manner as shown in . In particular, in region 447 near the upstream end of the cavity to be processed, the profile lines are completely separated from each other, there is no recirculation, and follow the outer electrode surface of the first conductive element. As previously described, this is a desired electrolyte behavior because a uniform and less turbulent electrolyte flow with little or no recirculation can provide uniform and efficient electrochemical machining. Effective electrochemical machining can refer to achieving a desired surface finish within a lower process time (e.g., cycle time). The inventors have also found that the uniformity of the velocity distribution is an important factor in electrochemical machining. The increase in the cross-section of the electrolyte channel through the mounting body 402 also provides a more uniform electrolyte flow (e.g., avoiding localized areas of high velocity spraying where the electrolyte might otherwise be discharged through relatively small holes).

[0304] It is desirable to improve the efficiency of electrochemical machining because power requirements may be reduced (e.g., resulting in lower operating costs). Cooling requirements may also be reduced. By reducing cooling requirements, the electrolyte may be pumped at a lower flow rate, which in turn reduces the risk of turbulence interfering with the electrochemical machining process. The electrolyte flow rate is balanced to provide a desired level of "flushing" of the machined material while avoiding the formation of turbulent eddies in the flow. An electrolyte flow rate of about 22 liters per minute has been found to be particularly effective.

[0305] Fig.15a is a perspective view of an electrode assembly 460 according to another embodiment. Fig.15a is taken roughly from one side of the assembly's mating surface 476, and Fig.15b is generally taken from the rear side 478. The electrode assembly 460 shares the Figures 12a to 12c Many features of the electrode assemblies 400 described in detail are common, and therefore only the differences will be described in detail.

[0306] The electrode assembly 460 includes a mounting body 462 and a first electrode 464 and a second electrode 466. The first conductive elements 468, 470 of the first electrode 464 and the second electrode 466 are respectively coupled to the mounting body 462 and are integral with the mounting body 462. Fig.15a and Fig.15b , for ease of illustration, the regions of the electrodes 464, 466 beyond the first conductive elements 468, 470 are modeled as a single piece, but in reality, the electrodes 464, 466 each include multiple conductive elements, as described elsewhere herein.

[0307] Distributed around each of the first conductive elements 468, 470 are a first plurality of electrolyte channels 472 and a second plurality of electrolyte channels 474, respectively. In addition to the presence of the second electrode 466 and the second plurality of electrolyte channels 474, many other features (particularly with respect to the electrolyte channels) are similar to those with respect to Figures 12a to 12c The features of the electrode assembly 400 described above are the same.

[0308] Go to Fig.15b , as described above, a general view of the rear face 478 of the electrode assembly 460 is provided. Fig.15b 472 and the second plurality of electrolyte channels 474 extend through the entire thickness of the mounting body 402 (e.g., in [e.g., Fig.15a [marked in] between the joint surface 476 and the rear face 478). Based on Fig.15a and Fig.15b , it should be understood that each of the first array 472 and the second array 574 of electrolyte channels are uniformly distributed around the entire periphery of each of the first electrode 464 and the second electrode 466, respectively. That is, the first plurality of electrolyte channels 472 (specifically, the downstream end thereof) are distributed around the first conductive element 468. Similarly, the second plurality of electrolyte channels 474 (specifically, the downstream end thereof) are distributed around the second conductive element 470. Although two electrodes 464, 466 are included in the illustrated embodiment, it should be understood that fewer or more electrodes may be included in other embodiments. In the case where the assembly includes more than one electrode, multiple electrolyte channels are preferably distributed around each electrode.

[0309] Go to Fig.16a and Fig.16b , an electrode assembly 500 according to another embodiment is provided. Although many previous electrode assemblies are used for machining turbine casings, electrode assembly 500500 is used for machining compressor casings.

[0310] Many core features of the electrode assembly 500 are common to the previous embodiments. For example, the electrode assembly 500 includes a mounting body 502 having an engagement surface 503 that can engage with the compressor housing to align the mounting body 502 with the housing. The electrode assembly 500 also includes an electrode 504 that includes a first conductive element 506, a second conductive element 508, and a third conductive element 510. Fig.16a and Fig.16b The electrode 504 is shown in a form-fitting configuration, but in Fig.16c The electrode 504 is shown in a movable configuration.

[0311] The rear face 512 of the mounting body 502 includes an aperture 514 through which an actuating device (e.g., in the form of a flexible element, such as a cord) may be passed to transform the electrode 504 from a movable configuration to a form-fitting configuration. The mounting body 502 also includes an integral bus bar 516 including a first socket 518 and a second socket 520 for electrically connecting the mounting body 502 and the electrode 504 to a power source. The mounting body 502 also includes an electrolyte conduit 522 that is integral with the mounting body 502 and is configured to receive electrolyte therethrough. Fig.17 A downstream electrolyte channel is shown and described (for completeness, it relates to a slightly different electrode assembly embodiment).

[0312] Fig.16b are different perspective views of the electrode assembly 500 . Fig.16c Electrode assembly 500 is shown with electrode 504 in a movable configuration.

[0313] Fig.17 is a perspective view of an electrode assembly 530 according to another embodiment. The electrode assembly 530 shares Figures 16a to 16c The electrode assemblies 500 share many features, and therefore only the differences are described in detail.

[0314] First, the electrode 532 of the electrode assembly 530 is a single rigid body. In other words, the electrode 532 is fixedly attached to the mounting body 534 so that there is no relative movement between the electrode 532 and the mounting body 534. Therefore, the electrode assembly 500 can be described as a single piece of equipment.

[0315] The electrode assembly 530 includes a mounting body 534. Distributed around the engagement surface 536 of the mounting body 532 are a plurality of electrolyte channels 538. The plurality of electrolyte channels 538 (particularly the downstream ends thereof) are holes uniformly and continuously distributed around the electrode 532 near the mounting body 534. Thus, the plurality of electrolyte channels 538 are distributed circumferentially around the electrode 532 and offset from the electrode 532.

[0316] Go to Fig.18a and Fig.18b , showing Fig.17 A perspective view of electrode assembly 530 mounted in place and coupled to compressor housing 540. Fig.18a Also shown is an electrolyte conduit 542 which is an axial conduit integral to and extending partially through the mounting body 534. Advantageously, the inclusion of the axial electrolyte conduit 542 reduces interruptions in electrolyte flow and provides reduced turbulent flow of electrolyte entering the volute of the compressor housing 540 during electrochemical machining and during pre-charging of the electrolyte. Fig.18aThe electrolyte conduit 542 in may be described as an internal conduit because it may be viewed as extending within the mounting body 534. Given that the electrode is fixedly attached to the mounting body 534 in this embodiment, it should be understood that it may be necessary to partially disassemble the compressor housing 540 in order to position the electrode within the volute.

[0317] Fig.18b is a partially cutaway plan view showing electrode assembly 530 extending through a volute of compressor housing 540 .

[0318] For the avoidance of doubt, while the illustrated embodiments show the use of a mounting body in combination with a multi-piece electrode (e.g., including multiple conductive elements having a movable configuration and a form-fitting configuration), the benefits obtained from uniform electrolyte distribution (e.g., including multiple electrolyte channels) and pre-charging the electrolyte (e.g., including electrically connected electrolyte conduits) are independent of the type of electrode used. For example, the same benefits can be obtained in an embodiment using a flexible electrode, which includes a flexible core and a plurality of conductive disks and non-conductive disks attached to the flexible core. Similarly, the same benefits can also be obtained in another embodiment, wherein the flexible electrode includes a flexible core, a plurality of elongated conductive segments attached to the flexible core, and a plurality of non-conductive rollers rotatably attached to the outside of the segments. In addition, it should be understood that if the electrode is a single rigid electrode fixedly attached to the mounting body, then the benefits will also be obtained.

[0319] Fig.19 Used when machining turbine housings Figures 12a to 12c Table of experimental data obtained for electrode assembly 400.

[0320] like Fig.19 As shown, the supply voltage was kept constant at 30V in all tests. Therefore, this test is a voltage driven test. Fig.12a ) and record its effect on the electrochemical machining process. The effect was determined by measuring the surface finish of turbine housings machined using the process (using a manual measurement - a stylus at the entry to the turbine housing) and the amount of material removed (again manually measured - a caliper across the entry).

[0321] like Fig.19 As shown in the table, a pipe length:diameter ratio of ~6 provides the best surface finish and the machining process removes the most material from the turbine housing. Fig. 20 As shown, the Fig. 20 yes Fig.19 From a plot of the data (surface finish plotted on the Y-axis), the best surface finish is obtained in embodiments where the conduit extension is at least about 6 diameters. This is believed to be due to a combination of the conduit extension providing uniform flow and the pre-charging effect on the electrolyte.

[0322] Fig.21 It is used when processing compressor housing. Figures 12a to 12c Table of experimental data obtained for electrode assembly 400.

[0323] like Fig.21 As shown, the current supply was kept constant at 1500A in all tests. Therefore, these tests are current driven tests. Again, changing the pipe 406 ( Fig.12a ) and record the effect on the electrochemical machining process.

[0324] like Fig.21 As shown in the table, a pipe length:diameter ratio of ~6 again provides the best surface finish and the machining process removes the most material from the compressor housing. Fig. 22 As shown, the Fig. 20 yes Fig.21 From a plot of the data (surface finish plotted on the Y-axis), the best surface finish is obtained in the embodiment where the tube extension is about 6 diameters. This is believed to be due to a combination of the tube extension providing uniform flow and the pre-charging effect on the electrolyte.

[0325] Fig.23 It is shown Figures 12a to 12c A plot of the effect of the conduit extension in diameter (X-axis) of the electrode assembly 400 on the Reynolds number of the electrolyte flow (Y-axis). The Reynolds number was manually calculated based on the results of CFD simulation data (where the electrolyte velocity at a given point within the turbine housing was obtained from the simulation data). Fig.23 The Reynolds number indicating electrolyte flow generally decreases from about 1 pipe extension to about 6 pipe extensions, with the change decreasing substantially at about 6 pipe extensions. This is also indicated by the dotted trend line. Therefore, Fig.23 It has been shown that for reasons of reduced turbulence, a pipe extension of approximately six times the diameter is an ideal embodiment.

[0326] Throughout this document, any electrode is preferably kept (e.g., fixed) stationary while electrochemical machining is being performed. That is, relative movement between the electrode and the cavity being machined is substantially prevented. Similarly, any component, the object of machining, is preferably kept stationary while machining is being performed.

[0327] Electrochemical machining can also be referred to as reverse electroplating, as material is removed rather than added (as in the case of electroplating). In contrast to electroplating, the polarity of the electrodes and the workpiece can also be reversed.

[0328] Reducing the gap between the electrical conductor and the inner wall may provide a more significant or stronger machining amplitude.

[0329] The compressor housing may be referred to as a compressor cover.

[0330] When the component is a turbine housing, the manufacturing process can be: 1. Sand casting for the initial casting geometry; 2. Shot peening of casting geometry; 3. Gate / runway grinding; 4. Electrochemical machining processes as described in this document; 5. Surface shaping.

[0331] An additive manufacturing process may be employed to form examples according to the present disclosure. A common example of additive manufacturing is 3D printing; however, other additive manufacturing methods are also available. Rapid prototyping or rapid manufacturing are also terms used to describe additive manufacturing processes.

[0332] As used herein, "additive manufacturing" generally refers to a manufacturing process in which successive material layers (multiple) are placed on top of each other to "build" or "additively manufacture" a three-dimensional component layer by layer. This is in contrast to some subtractive manufacturing methods (e.g., milling or drilling) in which material is removed successively to make a part. Successive layers are typically fused together to form an integral component, which may have various integral subcomponents. In particular, the manufacturing process may allow examples of the present disclosure to be integrally formed and include various features that are not possible when using existing manufacturing methods.

[0333] The additive manufacturing methods described herein are capable of manufacturing any suitable size and shape with a variety of features that are not possible using existing manufacturing methods. Additive manufacturing can create complex geometries without the use of any type of tools, molds, or fixtures, and produces little or no waste. Instead of machining a part from a solid billet of plastic or metal, most of which is cut away and discarded, the only material used in additive manufacturing is that required to shape the part.

[0334] Suitable additive manufacturing techniques according to the present disclosure include, for example, fused deposition modeling (FDM), selective laser sintering (SLS), stereolithography (SLA), direct selective laser sintering (DSLS), electron beam sintering (EBS), electron beam melting (EBM), laser engineered net shaping (LENS), electron beam additive manufacturing (EBAM), laser net shape manufacturing (LNSM), direct metal deposition (DMD), digital light processing (DLP), continuous digital light processing (CDLP), direct selective laser melting (DSLM), selective laser melting (SLM), direct metal laser melting (DLM), etc. Laser Melting (DMLM), Direct Metal Laser Sintering (DMLS), Material Jetting (MJ), Nanoparticle Jetting (NPJ), Drop On Demand (DOD), Binder Jetting (BJ), Multi Jet Fusion (MJF), Laminated Object Manufacturing (LOM) and other known processes. Binder jetting is a preferred process for making the conductive elements and electrodes described in this application.

[0335] The additive manufacturing process described herein can be used to form parts using any suitable material. For example, the material can be a metal, a composite material, or any other suitable material, which can be a solid, a liquid, a powder, a sheet material, a wire, or any other suitable form or combination thereof. More specifically, according to exemplary embodiments of the present subject matter, the additively manufactured parts described herein can be formed partially, entirely, or in some material combinations, including but not limited to pure metals, nickel alloys, chromium alloys, titanium, titanium alloys, magnesium, magnesium alloys, aluminum, aluminum alloys, iron, iron alloys, stainless steel, and nickel-based or cobalt-based superalloys (e.g., materials available from Special Metals Corporation under the name Inconel®). These materials are examples of materials suitable for additive manufacturing processes, which can be suitable for manufacturing the examples described herein. Stainless steel 316 A / L is a preferred material for manufacturing the mounting body, conductive elements, and electrodes described herein.

[0336] As described above, the additive manufacturing process disclosed herein allows a single component to be formed from a variety of materials. Therefore, the examples described herein can be formed from any suitable mixture of the above materials. For example, a component may include multiple layers, segments, or portions formed using different materials, processes, and / or in different additive manufacturing machines. In this way, components with different materials and material properties can be constructed to meet the needs of any particular application. In addition, although the components described herein are completely constructed from additive manufacturing processes, it should be understood that in alternative embodiments, all or a portion of these components can be formed by casting, machining, and / or any other suitable manufacturing process. In fact, any suitable combination of materials and manufacturing methods can be used to form these components.

[0337] Additive manufacturing processes typically manufacture a component based on three-dimensional (3D) information of the component, such as a three-dimensional computer model (or design file) of the component.

[0338] Thus, the examples described herein include not only the products or components described herein, but also methods of manufacturing such products or components by additive manufacturing, and computer software, firmware, or hardware for controlling the manufacturing of such products by additive manufacturing. The structure of one or more parts of a product may be digitally represented in the form of a design file. A design file or computer-aided design (CAD) file is a configuration file that encodes one or more surface or volume configurations of the shape of a product. That is, a design file represents the arrangement or shape of the geometry of a product.

[0339] The design file may be in any now known or later developed file format. For example, the design file may be in the Stereolithography or "Standard Tessellation Language" (.stl) format, which was created for 3D Systems' stereolithography CAD program, or in the Additive Manufacturing File (.amf) format, which is an American Society of Mechanical Engineers (ASME) standard, an Extensible Markup Language (XML)-based format designed to allow any CAD software to describe the shape and composition of any three-dimensional object to be manufactured on any additive manufacturing printer.

[0340] Other examples of design file formats include AutoCAD (.dwg) files, Blender (.blend) files, Parasolid (.x_t) files, 3D Manufacturing Format (.3mf) files, Autodesk (3ds) files, Collada (.dae) files, and Wavefront (.obj) files, but many others exist.

[0341] The design file may be generated using modeling (eg, CAD modeling) software and / or by scanning a surface of a product to measure the surface configuration of the product.

[0342] Once the design file is obtained, the design file can be converted into a set of computer executable instructions that, once executed by a processor, cause the processor to control the additive manufacturing equipment to produce a product according to the geometric arrangement specified in the design file. The conversion can convert the design file into slices or layers to be formed in sequence by the additive manufacturing equipment. The instructions (or otherwise referred to as geometry codes or "G-codes") can be calibrated for a specific additive manufacturing equipment and can specify the precise location and amount of material to be formed at each stage of the manufacturing process. As discussed above, the forming can be performed by deposition, by sintering, or by any other form of additive manufacturing method.

[0343] As desired, the code or instructions can be converted between different formats, converted into a set of data signals and transmitted, received as a set of data signals and converted into code, stored, etc. The instructions can be input to the additive manufacturing system and can come from a part designer, an intellectual property (IP) provider, a design company, an operator or owner of the additive manufacturing system, or from other sources. The additive manufacturing system can execute the instructions to manufacture a product using any of the techniques or methods disclosed herein.

[0344] The design file or computer executable instructions may be stored in a (temporary or non-temporary) computer readable storage medium (e.g., a memory, a storage system, etc.), thereby storing code or computer readable instructions representing the product to be produced. As described above, the code or computer readable instructions defining the product may be used to physically generate the object when the code or instructions are executed by the additive manufacturing system. For example, the instructions may include a precisely defined 3D model of the product and may be generated from various well-known computer-aided design (CAD) software systems, such as AutoCAD®, TurboCAD®, DesignCAD 3D Max, etc. Alternatively, a model or prototype of the component may be scanned to determine the three-dimensional information of the component.

[0345] Thus, by controlling the additive manufacturing device according to computer executable instructions, the additive manufacturing device can be commanded to print out one or more parts of a product. These can be printed in assembled or unassembled form. For example, different sections of the product can be printed separately (as a set of unassembled parts) and then assembled. Alternatively, different parts can be printed in assembled form.

[0346] In view of the above, an embodiment includes a manufacturing method by additive manufacturing. This includes the steps of obtaining a design file representing a product, and commanding an additive manufacturing device to manufacture the product in an assembled or unassembled form according to the design file. The additive manufacturing device may include a processor configured to automatically convert the design file into computer executable instructions for controlling the manufacture of the product. In these embodiments, the design file itself can automatically lead to the production of the product once it is input into the additive manufacturing device. Therefore, in this embodiment, the design file itself can be regarded as a computer executable instruction that prompts the additive manufacturing device to manufacture the product. Alternatively, the design file can be converted into instructions by an external computing system, and the resulting computer executable instructions are provided to the additive manufacturing device.

[0347] In view of the above, the design and manufacture of the implementation and operation of the subject matter described in this specification can be implemented using digital electronic circuits, or computer software, firmware or hardware, including the structures disclosed in this specification and their structural equivalents, or a combination of one or more of them. For example, the hardware may include a processor, a microprocessor, an electronic circuit, an electronic component, an integrated circuit, etc. The implementation of the subject matter described in this specification can be implemented using one or more computer programs, i.e., one or more computer program instruction modules, which are encoded on a computer storage medium for execution by a data processing device or for controlling the operation of a data processing device. Alternatively or additionally, program instructions can be encoded on an artificially generated propagation signal, such as a machine-generated electrical signal, optical signal, or electromagnetic signal, which is generated to encode information for transmission to a suitable receiving device for execution by a data processing device. The computer storage medium can be or be included in the following device: a computer-readable storage device, a computer-readable storage substrate, a random or serial access memory array or device, or a combination of one or more of them. In addition, when the computer storage medium is not a propagation signal, the computer storage medium can be the source or destination of the computer program instructions encoded in the artificially generated propagation signal. The computer storage medium may also be, or be included in, one or more separate physical components or media (eg, multiple CDs, disks, or other storage devices).

[0348] Although additive manufacturing techniques are described herein as being capable of manufacturing complex objects by building objects point by point, layer by layer (usually in a vertical direction), other manufacturing methods are possible and within the scope of the present subject matter. For example, although the discussion herein relates to adding materials to form successive layers, those skilled in the art will appreciate that the methods and structures disclosed herein can be implemented with any additive manufacturing technique or other manufacturing technique.

[0349] The described and illustrated embodiments are to be considered illustrative rather than restrictive, and it is to be understood that only preferred embodiments are shown and described, and that all changes and modifications that come within the scope of the invention as defined by the claims are intended to be protected. With respect to the claims, it is intended that when words such as "one," "a kind," "at least one," or "at least a portion" are used to describe a feature, there is no intent to limit the claim to only one such feature, unless the contrary is expressly indicated in the claim. When language such as "at least a portion" and / or "a portion" is used, the item may include a portion and / or the entirety, unless the contrary is expressly indicated.

[0350] The optional and / or preferred features described herein may be used alone or in combination with each other where appropriate, and in particular in combination as set forth in the appended claims. Where appropriate, the optional and / or preferred features of each aspect of the invention set forth herein may also be applicable to any other aspect of the invention.

Claims

1. A mounting body for a chamber of an electrochemical machining component, the mounting body comprising: an engagement surface capable of engaging with the component to align the mounting body with the component; at least a portion of an electrode coupled to the mounting body; and a plurality of electrolyte channels extending at least partially through the mounting body; Wherein, downstream ends of the plurality of electrolyte channels are distributed around at least a portion of the electrode.

2. The mounting body according to claim 1, wherein: The downstream ends of the plurality of electrolyte channels are evenly distributed around the electrode.

3. The mounting body according to claim 1 or 2, wherein: The downstream ends of the plurality of electrolyte channels are offset from the electrode.

4. The mounting body according to claim 1 or 2, wherein: The plurality of electrolyte channels extend through the electrode.

5. A mounting according to any one of the preceding claims, wherein: The electrolyte channel varies in cross-sectional area from the upstream end to the downstream end.

6. A mounting according to any one of the preceding claims, wherein: The electrolyte channel is defined by one or more ribs.

7. The mounting body according to claim 6, wherein: At least a portion of the electrode is coupled to the one or more ribs.

8. A mounting according to any one of the preceding claims, wherein: At least a portion of the electrode is integral with the mounting body.

9. The mounting body of any one of the preceding claims, further comprising an electrolyte conduit located upstream of and in fluid communication with the plurality of electrolyte channels.

10. The mounting body according to claim 9, wherein: The electrolyte conduit has an extent of at least about six times a major dimension of a cross-section of the conduit.

11. A method for electrochemically machining a cavity of a component using a mounting body according to any one of the preceding claims, the method comprising: coupling the mounting body to the component to align at least a portion of the electrode within the cavity; as well as A negative charge is applied to at least a portion of the electrode, and an electrolyte flow is provided through the plurality of electrolyte channels to distribute electrolyte around at least a portion of the electrode and remove material from an inner wall of the cavity.

12. The method according to claim 11, wherein: The electrolyte includes a liquid electrolyte.

13. The method according to claim 11 or 12, wherein: The electrolyte includes a plurality of bodies.

14. A mounting body for a chamber of an electrochemical machining component, the mounting body comprising: an engagement surface capable of engaging with the component to align the mounting body with the component; and an electrolyte conduit configured to receive a flow of electrolyte; wherein the electrolyte conduit has an extent of at least about one time a major dimension of a cross section of the conduit; and Wherein, the electrolyte pipe is electrically connected to the mounting body.

15. The mounting body according to claim 14, wherein: The electrolyte conduit is integral with the mounting body.

16. The mounting body according to claim 14 or 15, wherein: The electrolyte conduit has an extent of at least about three times a major dimension of a cross-section of the conduit.

17. The mounting body according to claim 16, wherein: The electrolyte conduit has an extent of at least about six times a major dimension of a cross-section of the conduit.

18. The mounting body according to any one of claims 14 to 17, wherein: The mounting body and the electrolyte pipe are made of the same material.

19. The mounting body according to any one of claims 14 to 18, wherein: The electrolyte conduit is axial in extension.

20. The mounting body of any one of claims 14 to 19, further comprising at least a portion of an electrode coupled to the mounting body.

21. The mounting body of any one of claims 14 to 20, further comprising a plurality of electrolyte channels extending at least partially through the mounting body, the plurality of electrolyte channels being disposed downstream of the electrolyte conduit.

22. A mounting according to claim 21 when dependent on claim 20, wherein: Downstream ends of the plurality of electrolyte channels are distributed around at least a portion of the electrode.

23. A method for electrochemically machining a cavity of a component using a mounting body according to any one of claims 14 to 22, the method comprising: applying a negative charge to the mounted body, and thus to the electrolyte conduit, and providing an electrolyte flow through the electrolyte conduit; pre-charging the electrolyte as it flows through the electrolyte conduit toward the cavity; and The pre-charged electrolyte is discharged into the cavity to remove material from the inner wall of the cavity.

24. The method according to claim 23, wherein: The electrolyte includes a liquid electrolyte.

25. The method according to claim 23 or 24, wherein: The electrolyte includes a plurality of bodies.

26. A mounting according to any one of claims 1 to 10 or 14 to 22 or a method according to claim 11 or 23, wherein: The component is a turbine housing or a compressor housing for a turbocharger, and wherein the cavity is a turbine housing volute or a compressor housing volute, respectively.

27. A computer program comprising computer executable instructions which, when executed by a processor, cause the processor to control an additive manufacturing apparatus to manufacture a mounting body according to any one of claims 1 to 10 or 14 to 22.

28. A method of manufacturing an electrode or a conductive element of an electrode by additive manufacturing, the method comprising: Obtaining an electronic file representing the geometric shape of a mounting body according to any one of claims 1 to 10 or 14 to 22; as well as An additive manufacturing device is controlled to manufacture the electrode or the conductive element of the electrode in one or more additive manufacturing steps according to the geometric shape specified in the electronic file.

29. A component comprising a cavity electrochemically machined using a mounting body according to any one of claims 1 to 10 or 14 to 22 and / or using a method according to any one of claims 11 or 23.

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