阅读说明：本技术 用于制造具有腔体的部件的方法 (Method for producing a component having a cavity ) 是由 U·施配希特 M·霍伊泽尔 M·布尔夏特 F-J·沃斯特曼 于 2019-01-09 设计创作，主要内容包括：本发明涉及一种用于制造具有腔体的导电部件(5)的方法。通过将由导电材料组成的承载层施加到可溶衬底(1)上,然后溶解并至少部分去除该衬底(1),实现了该部件的有效制造方法,该方法允许部件的壁厚的高度可变。(The invention relates to a method for producing an electrically conductive component (5) having a cavity. By applying a carrier layer consisting of an electrically conductive material onto a soluble substrate (1) and then dissolving and at least partially removing the substrate (1), an efficient manufacturing method of the component is achieved, which allows a highly variable wall thickness of the component.)

1. A method for manufacturing an electrically conductive component (5) with a cavity, characterized in that a fluid-carrying sealing layer (5) made of an electrically conductive material is applied onto a soluble substrate (1), in particular with a layer thickness of more than 3 micrometer, in particular more than 20 micrometer, so that the substrate (1) is covered by the layer (5) in a fluid-tight manner, after which the substrate (1) is dissolved and at least partially removed.

2. Method according to claim 1, characterized in that the carrier fluid sealing layer (5) is formed with a layer thickness of less than 20mm, in particular less than 5 mm.

3. Method according to claim 1 or 2, characterized in that the substrate has a strand-like design and the layer (5) is applied to one or more side surfaces of the substrate (1) on all sides, so that one or more side surfaces of the substrate are covered in a fluid-tight manner.

4. A method according to any one of claims 1 to 3, characterized in that the carrier layer (5) is applied onto the substrate (1) by applying particles.

5. Method according to any one of claims 1 to 4, characterized in that the substrate (1) is at least partially made of an electrically conductive material, in particular a metal or an electrically conductive plastic material, or of an electrically insulating material filled with electrically conductive particles.

6. Method according to any one of claims 1 to 5, characterized in that the substrate (1) is at least partially made of an electrically insulating material, in particular a plastic material, a wax, a ceramic material or a thermoplastic material.

7. Method according to any one of claims 1 to 6, characterized in that the substrate (1) is pre-coated with an electrically conductive pre-coating substance, in particular a metal, in particular in the form of particles or nanoparticles or an electrically conductive plastic material or carbon, in particular in the form of graphite or carbon nanotubes, before the application of the carrier layer.

8. Method according to any one of claims 1 to 7, characterized in that the carrier layer (5) is applied onto the substrate (1) by an electrochemical method, in particular an electrochemical or electroless method, a PVD coating method or a CVD coating method.

9. A method according to any one of claims 1 to 8, characterized in that the carrier layer (5) is applied to the substrate (1) by means of a plasma spraying process or by dipping the substrate into molten metal.

10. Method according to any one of claims 1 to 9, characterized in that the carrier layer (5) is applied onto the substrate (1) so as to surround it on all sides in a fluid-tight manner.

11. Method according to any one of claims 1 to 10, characterized in that the substrate (1) is separated from the carrier layer (5) by burning off, dissolving in a solvent, mechanical crushing, chemical decomposition, melting, evaporation or sublimation, and the substrate (1) is at least partially removed.

12. Method according to any one of claims 1 to 11, characterized in that after the application of the carrier layer (5), the substrate (1) is deformed, in particular bent, together with the carrier layer (5), after which the substrate is at least partially removed.

13. A method according to any one of claims 1 to 12, wherein prior to applying the coating, a helical substrate is formed which extends in the longitudinal direction of the helix and on which the coating is provided.

14. Method according to any one of claims 1 to 13, characterized in that after the application of the coating to the substrate, a semifinished product comprising the substrate and the coating is deformed or worked by means of shaping.

15. Method according to any one of claims 1 to 14, wherein after the application of the coating, a semi-finished product comprising the substrate (1) and the coating (5) is deformed into a coil geometry and then pressed in order to calibrate the coil body of the available installation space and to achieve a planar abutment of one turn of the coil body with the next.

16. Method according to any one of claims 1 to 15, wherein a plurality of conductive parts designed as strand-like conductors are twisted or transposed with respect to each other together with the substrate in order to achieve a reduced skin effect, in particular the insulation of the conductors/conductive parts with respect to each other is performed before or after twisting.

17. A method for manufacturing a substrate for use in the method according to any one of claims 1 to 16, characterized in that the substrate (1) is poured into a mould coated with a material which adheres to the surface of the substrate and which has properties enabling or promoting the deposition and/or adhesion of the carrier layer (5) on the substrate (1).

Technical Field

The invention belongs to the field of mechanical engineering and relates to the manufacture of conductive hollow parts. In particular, it can be advantageously applied in the field of electrical engineering. One important application is the manufacture of cooled passive electrical components, such as electrical conductors, in particular coils. Such coils may be used, for example, in the manufacture of inverter-powered electric motors. When hollow conductors can be used in the manufacturing process of such coils, efficient cooling is possible, which enables very high current densities to be achieved. However, the use of the invention is not limited to, for example, drivers or generators, but other elements, such as choke coils for high-frequency circuits, can also be realized. A particular feature of the hollow conductive member during use is that it may be optionally internally cooled. However, such components are complicated to manufacture, especially when small dimensions and/or thin-walled cross sections are to be achieved. In complex shapes, the manufacture of such parts has previously only been possible by additive manufacturing methods (3D printing).

Background

From EP0091352B1, a method of manufacturing a straight metal semiconductor is known, wherein a plurality of metal layers is applied on a substrate, which is dissolved so that the remaining coating forms a waveguide.

From EP0216421a1, a method for producing a light guide body is known, in which a substrate serving as a core is first coated and then the substrate is removed from the coating. For this purpose, the substrate is elongated in its longitudinal direction, reducing its cross-sectional dimension in the transverse direction during processing.

According to EP0129453B1, a method of manufacturing a metallic hollow conductor is known, wherein a layer of brass is first coated on a core, and then a layer of silver and copper are coated thereon, followed by dissolving the core and the layer of brass.

From US2004/0036569a1 it is known to manufacture high frequency modules comprising hollow conductors on or in a semiconductor wafer.

From DE3508794C2 it is known to produce injection-molded bodies in an injection mold, coat the mold, and transfer the coating to the molded part.

Disclosure of Invention

Against the background of the prior art, it is an object of the present invention to provide a method for manufacturing an electrically conductive component with a cavity, which method enables complex shapes to be manufactured with little effort and at low cost.

This object is achieved by a method for producing an electrically conductive component, based on the features of claim 1 according to the invention. Claims 2 to 12 represent advantageous embodiments of the method.

The invention also relates to a method for manufacturing a soluble substrate for use in the method according to the invention.

Accordingly, the present invention relates to a method for manufacturing an electrically conductive component having a cavity.

This object is achieved by: a carrier fluid sealing layer made of an electrically conductive material is applied onto a soluble substrate, in particular with a layer thickness of more than 3 micrometer, in particular more than 20 micrometer, such that the substrate is covered by the layer in a fluid-tight manner, after which the substrate is dissolved and at least partially removed.

By applying the electrically conductive material onto the substrate, the thickness and the material structure of the applied layer can be configured within a wide range. Layer thicknesses that are not achievable or are difficult to achieve by conventional metal casting processes, for example, can be achieved in this process. By applying the layer onto the surface of the substrate, complex shapes with undercuts can also be achieved using simple application methods. The geometric design of one or more cavities in the component formed in the layer can be easily configured by the shape of the substrate. By this method a fluid tight layer is created which forms a closed outer wall of the formed component, so that it can be cooled efficiently by the fluid in its cavity. However, the use of a cavity in the component is not limited to cooling, but any type of material and heat transfer may also be achieved by a fluid provided in the cavity, such as heating, temperature equalization or fluid conduction as material transfer.

Furthermore, it can be provided that the carrier fluid seal layer is formed with a layer thickness of less than 20mm, in particular less than 5 mm.

In particular, thin-walled thicknesses of components can be achieved very well by the described method.

Furthermore, it can be provided that the substrate has a strand-like design and that the layer is applied to the side surface(s) of the substrate on all sides, so that the side surfaces of the substrate are covered in a fluid-tight manner.

In this way, the method can be used particularly easily for producing a wire-shaped hollow component.

Using different techniques available for applying layers to substrates, it is possible to form thin layers in the desired material structure, so that the required wall thickness of the component is limited only by the requirements of current carrying capacity, fluid tightness and mechanical load-bearing capacity.

For example, the substrate can be designed as a strand with an arbitrary cross section and covered on all sides with a fluid-tight layer by using a coating method. Prior to coating, the substrate may have been placed in the final coil/spiral geometry and then coated. The preliminary geometry can be produced analogously to the winding process, wherein it is then still necessary to elastically expand or extend the preliminary geometry, so that the windings do not touch one another and can be coated. Also, by a molding process using a semi-finished product, or by a process similar to Fused Deposition Molding (FDM), a preliminary geometry may be produced in which the substrate material is made into a desired coil shape or an approximate shape by a nozzle, and the individual windings are not fused to each other. Furthermore, the preform made of the substrate thus formed may already be compressed or may be formed into the desired final contour by subsequent shaping, resulting in a high utilization of the available installation space of the coil when a simple preliminary geometry is used for the substrate. Then, after the substrate is dissolved, the tubular member remains. The cross-section of the substrate may be, for example, circular or elliptical, or may also be rectangular, square, triangular or polygonal. For example, if a component in the form of a coil is to be manufactured or further processed, a cross section allowing a higher number of turns is a suitable choice. After the component is manufactured, the component may be further shaped, for example by bending or winding, before or after the substrate is removed. However, it is also possible to produce a substrate of the desired complex shape, so that the three-dimensional shape of the component to be subsequently used is already predetermined by the coating of the substrate.

In the process of manufacturing the strand-like component, a continuous manufacturing process may also be provided by continuously moving the substrate through the coating device and coating it therein. After passing through the coating device, the coated substrate may enter another processing station where the substrate is dissolved. For example, in a subsequent station, the strand-like body with the tubular design can then be wound.

In one embodiment of the invention, provision can be made for the carrier layer to be applied to the substrate by applying particles. The particles may be, for example, microparticles or nanoparticles, or may also be individual atoms or clusters of atoms or droplets of a material, which are applied to the surface of the substrate using different methods, as will be described in more detail below.

In one embodiment of the method, it can be provided that the substrate is at least partially made of an electrically conductive material, in particular a metal or an electrically conductive plastic material, or of an electrically insulating material filled with electrically conductive particles, for example ceramic, glass or plastic.

As a result of the at least partially conductive design of the substrate, it is possible to carry out coating methods, such as electroplating methods, which can also be carried out in an electroless manner.

Other coating methods that require the generation of an electric current or the application of a voltage to the substrate are also possible by the conductive design of the substrate.

In an embodiment of the method according to the invention, it can also be provided that, for example, the substrate is made at least partially of an electrically insulating material, in particular a plastic material, wax, a ceramic material or a thermoplastic material.

In this way, the material used for the substrate can be freely selected from common, easily processable materials.

For this purpose, it can be provided, for example, that the substrate is precoated with an electrically conductive precoating substance, in particular a metal, in particular in the form of particles or nanoparticles or an electrically conductive plastic material or carbon, in particular in the form of graphite or carbon nanotubes, before the carrier layer is applied.

The precoat establishes the electrical conductivity of the surface, so that all electrically or electrically assisted coating methods are facilitated or made possible.

However, it can also be provided that the substrate is coated with particles or nanoparticles, which do not necessarily have to be electrically conductive, before the carrier layer is applied. In this way, the adhesion of subsequently applied carrier layers can be increased and/or the growth of such layers can be improved.

This also facilitates substrate coating methods other than electrically or electrically assisted methods.

Suitable precoats may also facilitate the separation of the resulting layer from the substrate in a subsequent step.

Provision can also be made for the substrate to be chemically etched before the carrier layer is applied.

For example, for the coating according to the invention, provision can be made for the carrier layer to be applied to the substrate by an electrochemical method, in particular an electrochemical or electroless method.

The advantages of the above method are as follows:

various metals and alloys can be used

Different metals/alloys can be used in the layers

The layer thickness can be controlled by the process parameters time, temperature, voltage, current, concentration, etc

Using chemically pure metals

Creation of defect-free/low-defect layers

Complex structure coating + uniform coating (wall thickness).

Alternatively, the hollow conductor present after the coating process and the substrate still present inside can be easily formed without destroying the hollow geometry. As a result, it is possible to transpose/twist a plurality of conductors and then move only the substrate out of the hollow conductor. This results in a very high frequency and little loss conductor due to the skin effect, which conductor is capable of achieving very high current densities due to possible internal cooling.

Alternatively, provision can also be made for the carrier layer to be applied to the substrate by means of a PVD coating process.

For example, the Physical Vapor Deposition (PVD) process may include the following methods: thermal evaporation of the subsequently deposited material, electron beam evaporation, laser beam evaporation, arc evaporation, molecular beam epitaxy. Furthermore, so-called sputtering is a coating method in which the starting material is atomized by ion bombardment and transferred into the gas phase. In addition, ion beam assisted deposition, ion plating, and Ionized Cluster Beam Deposition (ICBD) methods may be employed.

In principle, it should be noted that it is also possible to apply a plurality of layers in succession, which are subsequently formed as walls of the hollow component to be produced. For example, it is conceivable that the first layer ensures electrical conductivity and mechanical stability, while the layer applied thereto ensures fluid tightness, and vice versa.

In principle, provision can also be made for the carrier layer to be applied to the substrate by means of a CVD coating process.

A Chemical Vapor Deposition (CVD) process is understood to be a chemical vapor deposition process in which a substance from a gas phase is deposited on a substrate, wherein the substance chemically reacts with a surface or a material present on the surface, such as a pre-coating, to form a layer.

In order to produce a particular shape of the component produced, it can be provided, for example, that the carrier layer is applied to the substrate so as to surround the substrate on all sides in a fluid-tight manner.

Fluid tightness on all sides is to be understood as meaning that the substrate is virtually completely closed and sealed by the coating. In particular in the case of strand-shaped substrates, however, it can also be provided that the side surfaces of the substrate are sealed in a completely fluid-tight manner, while at least one end face or a plurality of end faces of the substrate remain uncoated. However, it can also be provided that the substrate is first coated on all sides in a fluid-tight manner and then that part of the coating is removed in a subsequent processing step, in order to first create a cavity in the manufactured component by removing the substrate and then to use it by adding a fluid.

Furthermore, as a coating method, provision may also be made for the carrier layer to be applied to the substrate by means of a plasma spraying process or by dipping the substrate into molten metal.

In principle, it can be provided that the substrate is deformed before the carrier conductive layer is applied, or that the substrate is deformed together with the carrier conductive layer after the carrier conductive layer is applied. This is particularly useful when the substrate has a spiral or helical shape.

For example, it can be provided that before the application of the coating made of electrically conductive material, a spiral or spiral-shaped substrate is produced and extends in the longitudinal direction of the spiral/spiral and is provided thereon, in particular in the form of an extension, with the coating made of electrically conductive material. In the extended state, an electrically insulating coating, for example made of paint or a plastic material or a metal oxide, may additionally be applied onto the electrically conductive coating. Thereafter, the substrate together with the coating may be compressed in the longitudinal direction or, if extension has occurred at least partly elastically and the substrate is elastic, may be transformed into an at least partly contracted shape in the longitudinal direction of the spiral by relaxation of the substrate. This process may be useful, for example, when the distance between the turns of the substrate in the powered-down state is small, e.g., less than 2mm or less than 1 mm. In this way, electrical contact of adjacent turns can be prevented.

In one embodiment of the method, provision may be made, for example, that after the application of the carrier layer, the substrate is deformed, in particular bent, together with the carrier layer, after which the substrate is at least partially removed. The carrier conductive layer may additionally be provided with an electrically insulating cover layer prior to deformation, for example by dipping, spraying, diffusion, spraying or powder coating, or by applying a reactive layer, in particular an oxide layer, for example by chemical treatment with a reactant.

By deforming the component together with the substrate, the cross section of the component can be maintained in a particularly stable manner, for example during bending, in particular when the component is designed as a strand-like hollow electrical conductor.

It can also be provided that after the application of the coating, the semifinished product comprising the substrate and the coating is shaped into a coil geometry and then pressed in order to calibrate the coil body of the available installation space and to achieve a planar abutment of one turn of the coil body with the next.

Furthermore, it can be provided that a plurality of conductive parts designed as strand-like conductors are twisted (transposed) together with the substrate in order to achieve a reduced skin effect, in particular that the insulation of the conductors/conductive parts with respect to each other is performed before or after twisting.

In order to remove the substrate from the carrier layer, it can be provided that the substrate is detached from the carrier layer by burning off, dissolving in a solvent, mechanical comminution, chemical decomposition, melting, evaporation or sublimation, and the substrate is at least partially removed.

This may occur in a subsequent process step after the substrate has been completely coated, or in a process step during which the continuous component, for example a tube, is continuously passed through after the coating process in the course of the manufacture of the continuous component that is also ongoing. The substrate may also be removed before or after the part is deformed, e.g. bent, to form the final shape.

A special method for manufacturing a substrate for use in one of the above methods may provide that the substrate is poured into a mould coated with a material that adheres to a surface of the substrate and that has properties that enable or promote deposition and/or adhesion of the carrier layer on the substrate.

In principle, the substrate can be produced as a core in an upstream molding process in simple or complex shapes, wherein methods known from molding technology can be used. Coatings of the type described for the shaping of substrates enable the coating to be transferred to the surface of the substrate and facilitate the coating process employed thereafter.

Drawings

The invention will be shown and described below on the basis of the drawings. In the drawings:

FIG. 1 shows a perspective view of a strand-like substrate;

FIG. 2 schematically illustrates a coating process;

FIG. 3 shows a perspective view of a substrate being coated;

FIG. 4 shows a perspective view of the fabricated component after removal of the substrate;

FIG. 5 shows a winding of a tubular member made in accordance with the present invention;

FIG. 6 shows the component bent prior to removal of the substrate;

fig. 7 and 8 show the spiral substrate in an extended and compressed state.

Detailed Description

Fig. 1 shows a cylindrical strand-shaped substrate 1, which is coated in the context of the method according to the invention. The substrate 1 is a simple example which can be used to manufacture a hollow winding having a hollow cylindrical cross section.

Fig. 2 shows a substrate 1, wherein arrows 2, 3, 4 indicate that particles, such as atoms, particles or nanoparticles or droplets, are applied from the outside onto the surface of the substrate 1. To this end, the substrate may optionally have a pre-coating, which may for example be electrically conductive, in order to be able to use a coating method that requires the application of a voltage, or for example a coating method that is used as an electroless plating deposition function.

Fig. 3 shows a substrate 1 comprising a carrier layer 5 applied thereto. The illustration is schematically shown and the thickness of the layer 5 and the ratio of the layer thickness to the substrate diameter are shown by way of example only. In many cases, the thickness of the layer/coating 5 will be smaller relative to the diameter of the substrate 1.

Fig. 4 shows the final product in the form of a hollow tube 5, wherein the substrate 1 is separated from the layer/coating 5 by liquefaction, burnout or otherwise removal.

Fig. 5 shows a spiral coil 6 consisting of a bent tube 7. It can be made into a curved shape as shown in fig. 5 by a similarly shaped substrate with a metal layer applied on the substrate. However, it is also possible to coat it first with a stretched, straight strand-like substrate and to produce a straight tube therefrom. As shown in fig. 6, for example, it may be bent together with the coated substrate. After the substrate is formed into the desired shape with the coating, the substrate can be removed. An advantage of the manufactured tubular member being deformed in this way together with the substrate still present therein is that during deformation the cross-section is maintained as supported by the substrate therein and bending of the tubular member can be avoided. Alternatively, fig. 6 shows the insulating coating 8 of the conductive layer 5 in the form of a dashed line.

However, it is also conceivable to first remove the substrate from the component and then deform the hollow component.

Fig. 7 schematically shows a side view of the substrate in the form of a spiral, wherein the individual turns 9, 10 are closely together in the relaxed state. Fig. 7 shows that the substrate is extended along the longitudinal axis 11 of the spiral by means of pulling forces 12, 13 before the coating process. The substrate may be composed of an elastomeric material, such as an elastomeric polymer.

Fig. 8 shows the helix after the coating process, wherein the dotted line 14 schematically represents the coating. The coating may be made of a conductive carrier metal layer, which then forms the conductive component. However, the coating may also comprise an electrically insulating cover layer made of a plastic material or an oxide or other material. Fig. 8 shows the compressed state in the longitudinal direction of the spiral, which either occurs after the tensile forces 12, 13 have been removed due to the relaxation of the substrate material or is actively achieved by applying a compressive force 15, 16 in the longitudinal direction of the spiral.

Two exemplary embodiments will be described below based on specific materials.

Exemplary embodiment 1:

waxes suitable for making complex structures by molding are mixed with graphite. As a result, conductivity is obtained in the mixture, which can be controlled by the proportion of admixed graphite (e.g., 1/10001/ohm cm). The resistance is chosen to be sufficiently small for the electrodeposition of a copper sheath on the substrate. The surface structure of the waxy substrate is also affected by the way the graphite is mixed. By configuring the surface structure of the substrate, for example to set a certain roughness or unevenness, the shape is transferred to the inner surface of the component formed by the applied layer, so that the flow behavior of the fluid through the hollow component can also be determined.

A copper sulfate solution may be used for electrodeposition, the part being cathodically polarized. The layer thickness of the copper sheath can vary in a wide range between a few micrometers to a few millimeters by means of the deposition parameters.

After the copper is deposited, the wax of the substrate melts at 120 ℃ and is thus removed.

Exemplary embodiment 2:

substrates of complex geometry can first be manufactured by a wax injection molding process or by a molding process of a tool. Alternatively and/or additionally to using an injection molding process, a cutting process is also conceivable.

The substrate produced in this way can be provided with a thin layer of platinum or palladium during sputtering in order to produce the electrical conductivity of the substrate surface. The substrate can then be electroplated with copper. In a subsequent step, the wax/substrate may be melted out of the component by heating.

The invention makes it possible to manufacture metal parts having complex shapes and internal hollow spaces (for example in the form of longitudinal channels) and having variably settable wall thicknesses. The metal coating can be performed using pure metals, such as copper or aluminum of the highest purity, so that the optimum conductivity level can be obtained. Such materials are not easily worked during the casting or forming process, and do not risk damaging the structure, which in addition may lead to leakage.

By this method, it is possible to manufacture a tool coated with metal from a profiled wire, which is cut to the appropriate dimensions in a subsequent process step and brought into the desired geometry, for example a coil, by forming.

In particular during the manufacture of internally cooled electrical conductors, coils or windings can be manufactured, which can significantly increase the current density compared to prior art coils/windings. In this way, for example, a mechanical drive with increased torque density can be achieved.