Method for electropolishing metal parts in floating electrical contact and electropolishing device for carrying out the method

Abstract

Disclosed is a method for electropolishing metal parts in floating electrical contact and an electropolishing device for carrying out the method, comprising: preparing the parts (1), which involves cleaning them; preparing the electrolytic medium (3); and electropolishing, wherein the parts (1) are immersed in the electrolytic medium (3) with an anode (4) and a cathode (5) and electric current (2) is applied; the immersed parts (1) floating or being submerged (mixed with the electrolyte) and isolated from the cathode (5) by at least one separator (6) with permeable free spaces (6a) that allow the electrolytic medium (3) to pass therethrough so as to come into contact with the cathode (5) and close the circuit when the electric current is applied (2).

Description

[0001] DESCRIPTION

[0002] PROCEDURE FOR ELECTROPOLISHING OF METAL PARTS IN FLOATING ELECTRICAL CONTACT AND DEVICE

[0003] ELECTROPOLISHING TO CARRY OUT SAID PROCEDURE

[0004] OBJECT OF THE INVENTION

[0005] The invention, as expressed in the title of this specification, refers to a method for electropolishing metal parts in floating electrical contact and to an electropolishing device for carrying out said method, providing advantages and characteristics, which are described in detail below, which represent an improvement of the current state of the art.

[0006] The object of the present invention falls on a method for smoothing and polishing metal parts which, based on the electrochemical process of applying an electric current to the part or parts immersed in an electrolytic medium, by means of contact of this with a cathode and an anode, is mainly distinguished in that the parts are incorporated floating in the electrolytic medium, preferably without any restriction, that is, without clamping to avoid clamping marks, and are isolated from the anode or the cathode by means of a separating and insulating element with permeable free spaces that allow the electrolytic medium to pass through to complete the circuit. The separating and insulating element according to the present invention includes, for example, an element with multiple elements, rigid or flexible in the form of a point, such as brush-type bristles; a mesh or by one or several permeable and insulating fabrics, such as permeable covers or containers.

[0007] 1. In addition, to improve the polishing effect, the pieces to be polished are removed and turned over, for which either the cathode or the anode, both elements, or even the electrolyte with the pieces themselves are mobile elements, a second aspect of the invention relating to an electropolishing device designed to carry out said procedure, which, in turn, can adopt different configuration variations to achieve the aforementioned movement options. FIELD OF THE EXTENSION OF THE INVENTION

[0008] The field of application of the present invention falls within the sector of the industry dedicated to the polishing of metal parts, focusing particularly on electropolishing systems.

[0009] BACKGROUND OF THE INVENTION

[0010] As is known, electropolishing is a widely used chemical and electrochemical process to improve the surface of metal parts. It is essentially based on applying electric current to the metal piece or pieces that will be immersed in an electrolytic solution that is put in contact with an anode, for example immersed in the solution to decompose, and with a cathode that is connected to a power source, which causes the dissolution and controlled removal of small amounts of material and imperfections that may be on the surface of the piece or the adhesion of dissolved particles of the piece that acts as an anode, for example in galvanizing processes, thereby obtaining a smooth and polished finish.

[0011] Also known is an electropolishing method using an electrolytic medium comprising: a set of solid particles that contain a liquid electrolyte inside, a quantity of conductive and / or electrolytic solution or water retained in the solid particles, and a liquid, less conductive than the solid particles, immiscible that covers the solid particles, such that when a solid particle comes into contact with the piece to be polished, the electrical conductivity between the solid particle and the piece to be polished causes an ionic exchange and consequently the polishing of the piece to be polished.

[0012] The problem with this procedure is that the part or parts must be held in place to keep them immersed in the electrolytic medium, which means that marks will inevitably remain in the contact area between the surface of the part and the holder. This can be a significant problem, especially for small and / or delicate parts that must be perfectly polished over their entire surface.

[0013] To avoid these marks, the parts can be placed in the electrolytic medium without being held firmly, such as within an element such as a basket connected to an electrode, as described in Spanish patent P 202030086, ES2831105 A1. In this case, the parts to be polished are placed in the container where they come into contact with a first electrode connected to the electrical source. This provides an electrical current that flows between the parts and the second electrode through the particles of the medium. The system produces a relative movement of the particles with respect to the parts to be polished.

[0014] However, this presents the problem of direct contact between the parts and the cathode that supplies the current to the electrolyte, for example, when they are deposited by gravity on the bottom of the container in which they are contained, and this causes unwanted marks to appear on their surface.

[0015] The objective of the present invention is, therefore, the development of an improved type of electropolishing process that allows for solving this problem and minimizing or completely eliminating contact marks caused by clamping on the surface of the parts, as well as their mass production.

[0016] SUMMARY OF THE INVENTION

[0017] The method for electropolishing metal parts in floating electrical contact and the electropolishing device for carrying out said method proposed by the invention are configured as a solution to the objectives previously stated.

[0018] Specifically, what the invention proposes in some of its aspects, as indicated above, is a galvanic surface treatment process, such as electropolishing for smoothing and polishing metal parts, which is conventionally based on the application of an electric current to the part or parts immersed in an electrolytic medium, which is brought into contact with a cathode and an anode, to generate said current, is characterized in that the parts are incorporated in the electrolyte floating, preferably without any restriction, that is, without support to avoid fixed support marks, minimizing or totally eliminating contact marks due to support on the surface thereof. Said parts are isolated from direct simultaneous contact with the anode and the cathode by incorporating between this and at least one part, one or more separating and insulating elements.

[0019] In some cases, said suspension means or separating and insulating element comprises permeable free spaces such that they allow the electrolytic medium to pass through to close the circuit and at the same time define a minimum contact surface with the workpiece to be treated and one of the two electrodes. In some embodiments of the invention, the minimum contact surface comprises pointed elements or points.

[0020] The term "parts floating in the electrolyte" should be understood in this document as meaning that the parts are at least partially submerged in the electrolyte medium by means of a suspension medium. For example, this suspension medium is sometimes achieved by means of one or more separating and insulating elements with permeable free spaces that allow the electrolyte medium to pass through.

[0021] In other examples of the invention, the suspension medium is achieved with Drylyte particles.

[0022] Embodiments comprising said DryLyte particles include the use of conductive solid particles that retain an electrolytic liquid, such that when a solid particle comes into contact with the workpiece to be polished, the electrical conductivity between the solid particle and the workpiece to be polished causes an ionic exchange and consequently the polishing of the workpiece to be polished:

[0023] Solid particles can be ceramic, polymeric, organic, inorganic, of plant origin, etc.

[0024] Preferably, the conductive particles are made of ion-exchange resin, as this promotes ionic conductivity. More preferably, the particles are made of cation-exchange resin, as this allows them to capture metal ions extracted during electropolishing processes and maintain their initial properties. In some specific embodiments, they are made of sulfonated polystyrene polydivinylbenzene.

[0025] Typically, ion exchange particles with macropores are called macroporous particles, and particles with microporosity are called gel-like particles. Both types are suitable for use in this invention.

[0026] In some cases, said conductive solid particles are found in an environment including a gas, in others in a liquid environment, and in still others in a gaseous environment or a combination of the two. In some embodiments of the invention, in order to have better control over the fluidity and suspension capacity of the electrolytic medium, a liquid medium can be used. Depending on the rheology and viscosity of the assembly formed by the workpiece(s) to be polished, conductive solid particles, and liquid, it is possible to control the ability to suspend the workpieces and isolate them from one of the two electrodes while allowing them to connect to the other, using the ratio between said elements. An increase in the proportion of liquid will promote permeability, decreasing the ability to keep the workpiece(s) in suspension, while an increase in the proportion of conductive solid particles will have the opposite effect.

[0027] In some cases, the added liquid is not significantly conductive with respect to the conductivity of the solid particles, which are the ones that mostly guide the ion exchange process. For example, it is possible to use aliphatic hydrogen carbonate chains between 7 - 25 C. In other cases, the liquid used comprises a conductive solution. In some particular embodiments of the invention, in which it is desired to guide the ion exchange through the particles and increasing the capacity for electrical charge transmission between them, the liquid is an emulsion between an immiscible conductive solution and a non-conductive solution, which promotes their electrical connection by having greater ease to form conductive menisci between them, while allowing the modification of the rheology presented by the liquid medium.

[0028] The size, stiffness, density, and quantity of the solid particles, relative to those of the workpiece(s) to be polished, are parameters that must be configured to control the movement of the workpiece(s) to be polished until they touch the anode or cathode, thereby controlling the polishing process. Adjusting the packing factor between the solid particles in their corresponding environment, taking into account the qualities of the workpiece(s) to be polished, is an important aspect in order to modify the thrust that the solid particles exert on the workpieces, thereby controlling their suspension and, therefore, the contact between them and the electrodes.

[0029] This is a factor to consider for a satisfactory surface treatment. It is important to ensure sufficient electrical contact time between the parts and one of the two electrodes for an efficient polishing process and short enough to avoid excessive attack. Therefore, fluidizing elements or vibrations can be introduced to weaken or strengthen the force of the particles that suspend the parts to be polished, allowing the electrical contact between the parts and the electrodes to be controlled at will.

[0030] The parts, which in some embodiments are not held by any clamp or arm system, can move freely in the electrolyte, changing the point of electrical contact with the electrolyte and consequently avoiding clamping marks, even in those cases in which the suspension means incorporates said separating and insulating elements.

[0031] An advantage of the electropolishing process of the invention is the production of polished parts with isotropic surfaces that improve the biocompatibility of medical products. Another advantage of the electropolishing process of the invention is the production of mechanically loaded components with greater durability and resistance to dynamic fatigue, while increasing the lambda factor in their elastohydrodynamic lubrication. In order to achieve a homogeneous result or an isotropic surface, in some embodiments of the invention, contact elements are designed with the parts to be polished that, integral with the container, promote their random or non-random orientation within the processing system. The relative movement between the parts, the medium, and the container where they are located can be configured in such a way as to achieve this effect.This contributes to averaging the galvanic effects resulting from its random orientation at will, in such a way that it ends up providing homogeneous or heterogeneous results depending on the application in question.

[0032] Another relevant factor for some embodiments of the invention concerns the anodic and cathodic surfaces of the electrodes. In some cases, some parts come into contact with the anodic electrode, while others are connected to the anode via a connecting cable between the various parts and the anode. In certain applications, the difference in ohmic drop between the extremes in the situation explained above requires increasing or decreasing the exposed anodic surface area in order to vary the homogeneity, precision, and speed of the treatment. Increasing the contact surface area results in greater homogeneity and precision.However, under the same conditions, reducing the contact surface while encouraging the workpieces to connect between several layers of other workpieces located between them and the anode will increase the treatment speed of the workpieces in the part furthest from the anode and will decrease the treatment speed of the rest of the workpieces. In some embodiments of the invention, a ratio between the surface(s) of the electrodes and the surface of the workpiece(s) to be polished of between 100:1 and 1:10 is used, particularly between 50:1 and 1:1, more particularly between 20:1 and 10:1.

[0033] For example, a separating and insulating element, according to the present invention, may be formed in some embodiments by one or more bristle-based brushes, or by one or more mesh layers, or by one or more permeable and insulating fabrics, such as permeable covers or containers.

[0034] In any case, preferably, the polishing of the pieces is carried out by moving, removing and / or turning the pieces, so that the applied current acts uniformly and homogeneously on all the different faces and / or recesses of its surface, for which the procedure contemplates, at least, the following options of action and execution:

[0035] A first option, in which the cathode presents movement that, in turn, causes the pieces to be removed and / or turned, while the anode remains static.

[0036] A second option is where the cathode remains static while the anode is the one that presents the movement that causes the pieces to be removed and / or turned.

[0037] A third option is that both the anode and cathode move, causing the pieces to be removed and / or turned over. The movement of the anode and cathode can be simultaneous or alternating. A fourth option is that both the anode and cathode remain static while the electrolytic medium with the suspended pieces moves, causing them to be removed and / or turned over.

[0038] A fifth option is that the suspension medium, for example, one comprising separating and insulating elements with permeable free spaces such that they allow the electrolytic medium to pass through, is the one that presents the movement that causes the removal and / or turning of the suspended pieces.

[0039] For its part, the electropolishing device object of the present invention to carry out the procedure described above comprises, at least, the following elements:

[0040] A container with an electrolytic suspension and with the capacity to incorporate the piece or pieces to be polished, submerged and / or floating in said electrolytic medium.

[0041] A piece of metal or other conductive material constituting the anode that is incorporated into the vessel so that it is immersed in the electrolytic suspension or in contact with it.

[0042] A piece of metal or other conductive material constituting the cathode that is in contact with the electrolytic suspension in the container and can be connected to an electrical power source, for example, a generator, such that, when activated, it closes the circuit with the anode, causing the passage of electrical current through the electrolytic medium and thus, the polishing of the pieces immersed in it.

[0043] Preferably, some embodiments also include an insulating lid, which covers the container containing the electrolytic medium.

[0044] In some preferred embodiments, including, for example, in combination with any of the preceding embodiments, the device comprises, incorporated between the cathode and the electrolytic medium within the container, a suspension or separator means made of insulating material with permeable free spaces that allow part of said electrolytic medium to pass through so that it comes into contact with the cathode and closes the circuit. In some embodiments, such as, for example, in combination with any of the preceding embodiments, said suspension or separator means also has a configuration based on points or pointed, pointed, penetrating, incisive, or thorny elements; assemblies with protuberances or hooked elements, such as, for example, a Velero® type, or other irregular shapes, such as, for example, a tangled skein-like fabric of threads such as a scouring pad-like fabric.This configuration is present, at least on its contact surface with the electrolytic medium, and preferably, at least in the contact area with the parts immersed in said medium.

[0045] In a preferred embodiment, the separator is made up of one or several bristle brushes arranged with the base fixed to the cathode and the tips facing the suspension.

[0046] In other embodiments, the suspension or separator means is made up of one or more layers of mesh, or one or more permeable and insulating fabrics, such as permeable covers or containers.

[0047] For example, in one embodiment, the suspension or separator means comprises a sleeve, bag, or container with holes inside that holds the parts to be polished without allowing them to escape, while allowing the electrolytic medium to pass from the inside of the bag to the outside of the bag. In this embodiment, the workpiece is preferably movable within the sleeve, bag, or container. In one or more variants of this embodiment, a non-conductive stirring or agitating arm is provided to facilitate relative movement between the parts to be polished, wrapped in the sleeve, bag, or container, and the electrolytic medium. This bag allows electrical contact of the parts with the anode.

[0048] In some preferred embodiment, the electropolishing device has at least the following variants with different actuation or configuration options.

[0049] In a first embodiment of electropolishing, where the cathode moves and the anode remains static, the container with the electrolytic suspension and the anode is a fixed body that has a grooved annular configuration on which a carousel of metallic vapor heads rotate, which act as a cathode, and are covered with bristle brushes, meshes or permeable surfaces that fit into the grooved annular body, so that they remove the pieces incorporated therein.

[0050] In a second embodiment of electropolishing, where the cathode remains static and the anode exhibits movement, the container with the electrolytic suspension is made up of a fixed tray to the base of which a plurality of bristles or permeable surface are fixed that completely cover it, there being a string of bars that make up the anode that move from one end to the other of the tray.

[0051] In a third embodiment of electropolishing, where the anode and cathode move, the container with the electrolytic suspension is a rotating drum, preferably arranged in a horizontal position, inside which the anode is attached to its inner wall, there being a head that defines the cathode that is covered with a bristle brush or permeable surface and which, in turn, preferably rotates through an angled shaft inside the drum or is held in the lower position of the rotating drum.

[0052] In a fourth embodiment of electropolishing, where both the anode and the cathode remain static while the electrolytic medium with the pieces in suspension is the one that presents movement that causes the removal and / or turning of the pieces in suspension.

[0053] And a fifth variant of electropolishing, where the suspension medium, for example, the one comprising separating and insulating elements with permeable free spaces such that they allow the electrolytic medium to pass through, is the one that presents the movement that causes the removal and / or turning of the pieces in suspension.

[0054] DESCRIPTION OF THE DRAWINGS

[0055] To complement the description being provided and in order to assist in a better understanding of the features of the invention, this specification is accompanied, as an integral part thereof, by drawings in which the following is represented, for illustrative and non-limiting purposes: Figure 1.- Shows a schematic sectional representation of an example of an electropolishing device for carrying out the process that is the object of the invention, showing the main parts and elements it comprises, as well as their arrangement; Figure 2-A.- Shows a schematic perspective view of an example of an embodiment of the electropolishing device of the invention in an embodiment variant thereof with a moving cathode and a static anode; Figures 2-B and 2-C.- Show elevation and plan views of the example of the device shown in Figure 2-A; Figure 2-D.- Shows a sectional view of the device, according to section AA indicated in Figure 2-B; Figure 2-E.- Shows a sectional perspective view of the device of the invention, according to the example shown in Figures 2-A to 2-D. Figures 3-A and 3-B.- Show respective schematic perspective views of an example of the electropolishing device of the invention in a second embodiment variant thereof with the cathode static and the anode provided with movement, having been represented with the container covered with the insulating lid and without it; Figure 3-C.- Shows a plan view of the example of the device shown in Figures 3-A and 3-B; Figure 3-D.- Shows a sectional view of the device according to section BB indicated in Figure 3-C; Figure 4-A.- Shows a schematic perspective view of another example of the electropolishing device of the invention in a third embodiment variant thereof with the cathode and anode provided with movement; Figures 4-B and 4-C.- Show elevation and plan views of the example of the device shown in Figure 4-A; Figure 4-D.- Shows a sectional view of the device according to the section CC indicated in Figure 4-C; Figures 5-A and 5-B.- Show schematic sectional representations of another example of the electropolishing device object of the invention, similar to that shown in Figure 1 , in this case an example that has movement and the separating element that isolates the pieces in the upper part so that they have the gravity in their favor, specifically an example with translational movement in the anode in Figure 5-A and with translational movement in the cathode in Figure 5-B; and figure number 5-C.- Shows a schematic representation in section of another example of the device of the invention similar to that shown in figures 5-A and 5-B, in this case with vibratory or turning movement.

[0056] Figure 6-A shows a schematic perspective view of an example mechanism of the present invention in a fourth embodiment variant thereof with the cathode and anode provided with movement; Figure 6-B shows a schematic representation of a perspective section; and Figure 6-C shows a detailed schematic representation of an elevational section.

[0057] PREFERRED EMBODIMENT OF THE INVENTION

[0058] In view of the aforementioned figures, and in accordance with the adopted numbering, several non-limiting embodiments of the device for electropolishing metal parts in floating electrical contact of the invention can be observed, which comprises what is described in detail below. As shown in Figure 1 , the present invention includes a method for galvanic surface treatment of conductive parts (1) in floating electrical contact, which comprises the following steps:

[0059] Immersing the part / s (1) in an electrolytic medium (3) located between an anode (4) and a cathode (5); applying electric current (2) flowing between the anode (4) and the cathode (5) including electrical contact between the parts (1) and the electrolytic medium (3); characterized in that the parts (1) that are immersed in the electrolytic medium (3) float therein and are isolated, at least, from the anode (4) or the cathode (5) by means of a suspension means or a separator (6) that includes permeable free spaces (6a) that allow the electrolytic medium (3) to pass through them to make contact with the anode (5) and / or the cathode (5) in order to close the circuit when the electric current (2) is applied.

[0060] In some particular embodiments, Figure 1 includes a galvanic surface treatment method according to the invention, intended to treat conductive parts (1) by applying electric current (2) in an electrolytic medium (3) in which they are immersed, comprising at least:

[0061] - an electropolishing stage itself, where the pieces (1) are immersed in an electrolytic medium (3), such as an electrolytic suspension, prepared in the previous stage, an anode (4) (negative electrode) is placed, a cathode (5) (positive electrode) is placed and an electric current (2) is applied, for example from an external source (not shown), so that the anode (4) and the cathode are connected to each other.

[0062] (5) by means of the parts (1) and through the electrolytic medium (3), such that the metal ions dissolve from the surface of the parts and are deposited in the medium and in the cathode (5);

[0063] Preferably, the electropolishing process comprises one of the following steps: a preliminary step of preparing the parts (1), where they are cleaned and degreased to remove residues and possible contaminants from the surface using detergents, solvents or other methods depending on the type of metal and the dirt present; a step of preparing the electrolytic medium (3), where a solution is prepared with the composition and concentration of acids and other chemical components specific to the type of metal to be polished; a final step of rinsing and drying where, after reaching the desired level of polishing, the parts (1) are removed from the electrolytic medium (3) and rinsed with a neutralizing solution.

[0064] And, from said succession of stages, the process of the present invention comprises an electropolishing stage, where the pieces (1) are immersed in an electrolytic medium (3) floating or submerged therein, preferably without any fixed fastening and, in addition, the pieces (1) are isolated from the anode (4) or the cathode (5) by means of at least one suspension means or a separator (6) with permeable free spaces (6a) that allow the electrolytic medium (3) to pass through it to make contact with the anode (4) or the cathode (5) and close the circuit when the electric current (2) is applied.

[0065] Furthermore, preferably, said at least one suspension means or a separator (6) that isolates the pieces (1) from direct contact with the anode (4) or with the cathode (5), is an element that has a configuration with a surface of points, protuberances or roughnesses that determine an area of ​​minimum contact with the pieces (1), preferably based on points, or any of the other versions of separators described in this document.

[0066] In one embodiment, a suspension means or the separator (6) is formed by one or more groups of bristles, and, alternatively, by mesh or by one or more permeable and insulating fabrics, such as permeable covers or containers. In any case, preferably, in the electropolishing stage, the pieces

[0067] (1) are stirred and / or turned to improve the effect and so that the electric current (2) acts in a uniform and homogeneous manner on all the different faces and / or recesses of its surface, for which the main implementation options are preferably contemplated: by means of the movement of the cathode (5), while the anode (4) remains static); by means of the movement of the anode (4), while the cathode (5) remains static; or by means of the movement of both the anode (4) and the cathode (5). by means of the movement of the electrolytic medium (3) with said pieces (1) submerged in it, while preferably both the anode (4) and the cathode (5) remain static.

[0068] - by moving the suspension medium or a separator

[0069] (6) which isolates the parts (1) from direct contact with the anode (4) or the cathode (5).

[0070] Looking at figures 5-A, 5-B and 5-C, it can be seen how the aforementioned movements of the anode (4) and / or the cathode (5) can be translational movements or vibratory or tumbling movements. Furthermore, the separating element (6) can be located at the top, so that the pieces (1) to be polished have the force of gravity in their favor.

[0071] For its part, the electropolishing device (100, 100', 100") of the present invention, designed to carry out the procedure described above, comprises at least: a container (7) suitable for containing the electrolytic suspension (3) and capable of incorporating the piece or pieces (1) to be polished submerged therein; a piece of metal or other conductive material constituting the anode (4) incorporated in the container (7) such that it is totally or partially submerged in the electrolytic suspension (3); and a piece of metal or other conductive material constituting the cathode (5) that is in contact with the electrolytic suspension (3) of the container and that can be connected to an electrical power supply (not shown).

[0072] Furthermore, said embodiment comprises, incorporated between the anode or the cathode (5) and the electrolytic suspension (3) of the container (7), a suspension means or a separator (6) of insulating material, which keeps the pieces (1) isolated from direct contact with the anode (4) or with the cathode (5), the suspension means or the separator (6) have permeable free spaces (6a) that allow part of the electrolytic suspension (3) to pass through to make contact with the anode (4) or with the cathode (5) and close the circuit.

[0073] Preferably, the electropolishing device (100, 100', 100") comprises an insulating lid (8), which covers the container (7) with the electrolytic suspension (3)

[0074] Preferably, the suspension means or the separator (6) have a structure based on points or pointed, pointed, penetrating, incisive or thorny elements; assemblies with protuberances or hooked elements such as Velero® type, or other irregular shapes, such as a skein-like fabric of tangled threads such as a scouring pad-like fabric, at least on its surface in contact with the electrolytic suspension (3), which define a minimum contact area with the pieces (1).

[0075] In one embodiment option, the suspension means or separator (6) is formed by groups or bristle brushes, as seen in the figures, or by mesh, or by one or several permeable and insulating fabrics, such as permeable covers or containers.

[0076] Looking at figures 2-A to 2-E, it can be seen how in a first embodiment of the electropolishing device (100) of the invention, where the cathode (5) moves and the anode (4) remains static, the container (7) with the electrolytic suspension (3) and the anode (4) includes a fixed body of grooved annular configuration on which a carousel-shaped structure (9) rotates with several metal heads, which act as a cathode (5), and which are arranged radially hanging from it, which heads are covered with bristle brushes that fit into the grooved annular body acting as a means of suspension or separator element (6) between the cathode (5) and the pieces (1) incorporated therein submerged in the electrolytic medium or suspension (3).

[0077] Preferably, the carousel structure (9) comprises an upper circular base from which the cathode heads (5) hang, which, at the same time, defines the insulating cover (8) of the annular container (7) when it is coupled thereto, there being on said cover (8) a rotating central axis (10) through which the movement is printed to the heads that define the cathode (5) so that they rotate circularly through the annular channel that defines the container (7).

[0078] Preferably, the annular container (7) is placed on a support base

[0079] (11) supported on a series of springs (12), having been provided on both sides and in the central hollow of the container (7) respective cylinders (13) for the connection to the power supply that will apply the electric current to the assembly and, optionally, the insertion and extraction of the electrolytic suspension (3), the central cylinder (13) being also supported on a spring (12).

[0080] Looking at figures 3-A to 3-D, it can be seen how in a second embodiment of the electropolishing device (100') of the invention, where the cathode (5) remains static and the anode (4) is the one that moves, the container (7) in which the electrolytic suspension (3) is incorporated and where the pieces (1) to be polished are immersed is made up of a fixed tray, for example of an elongated, elliptical, rectangular or similar shape, the bottom of which constitutes the cathode.

[0081] (5) and fixed thereto, as a means of suspension or separating element (6), are a plurality of bristles that completely cover said bottom, there being in the upper part of said container (7) in the form of a tray a string of mobile bars that make up the anode (4) and that, attached to an upper support (14), move along the tray, from one end to the other of the same, to remove the pieces (1).

[0082] Preferably, the tray that defines the container (7) has an insulating lid (8) and, similarly to the example of the previous vahante, the annular container (7) is placed on a support base (11) resting on springs (12), with respective cylinders (13) being provided on both sides and in the lower part of the same for connection to the power supply that will apply the current and, optionally, for the insertion and extraction of the electrolytic suspension (3).

[0083] For its part, looking at figures 4-A to 4-D, it can be seen how in a third embodiment of the electropolishing device (100") of the invention, where both the anode (4) and the cathode (5) present movement, the container (7) with the electrolytic suspension (3) in which the pieces (1) to be polished are immersed is a rotating drum, which rotates on its axis, preferably driven by a motor (15) coupled to one end of the drum and which, at the same time, serves as a power source to apply the current, inside which said drum incorporates a plate fixed integrally to its inner wall acting as an anode (4), as well as a head that defines the cathode (5) and which, in turn, rotates inside the drum-shaped container (7) through an angled shaft (16) to which it is connected by the opposite end where the insulating cover (8) that closes said container (7) is contemplated,this cathode head (5) being covered with a bristle brush or permeable surface that acts as a suspension medium or separator (6) to prevent direct contact with the pieces to be polished (1). In this case the container (7) in the form of a rotating drum is supported by an L-shaped structure (17) whose horizontal branch serves as a base and whose vertical branch serves as a fixation, through a coupling piece (18), between the axis of the drum (7) and the motor (15) that moves it.

[0084] In the particular case detailed in Figure 6, it is observed how in a fourth variant of the invention the electropolishing device has a tank (4) in which the piece or pieces to be polished (2) are immersed and come into contact with the cathode electrode (3) through an electrolytic suspension medium (9) that circulates through holes that prevent the cathode-piece short circuit for dimensional reasons; where said pieces (2) come into direct electrical contact by means of a cathode (6) and are pushed by it when coupled to means to provide the cathode (3) with movement (1); and where the electrolytic suspension medium (9) together with the pieces are fluidized by means of a vibration transmission system (7) that is optionally connected by means of the support of the structure (8) through resonators or vibration dampers (5) in order to efficiently control the fluidification provided.

[0085] Having sufficiently described the nature of the present invention, as well as the manner of putting it into practice, it is not considered necessary to make its explanation more extensive so that any expert in the field understands its scope and the advantages derived from it.

Claims

CLAIMS 1.- Procedure for galvanic surface treatment of conductive parts (1) in floating electrical contact, which includes the following steps: Immersing the part / s (1) in an electrolytic medium (3) located between an anode (4) and a cathode (5); applying electric current (2) flowing between the anode (4) and the cathode (5) including electrical contact between the parts (1) and the electrolytic medium (3); characterized in that the parts (1) that are immersed in the electrolytic medium (3) float therein and are isolated, at least, from the anode (4) or the cathode (5) by means of a suspension means or a separator (6) that includes permeable free spaces (6a) that allow the electrolytic medium (3) to pass through them to make contact with the anode (5) and / or the cathode (5) in order to close the circuit when the electric current (2) is applied. 2.- Method for electropolishing metallic pieces in floating electrical contact, according to claim 1, characterized in that said at least one means of suspension or separator (6) that isolates the pieces (1) from direct contact with the anode (4) or the cathode (5), is an element that has a configuration with a surface of points, protuberances or roughnesses that determine an area of ​​minimum contact with the pieces (1). 3.- Method for electropolishing metal parts in floating electrical contact, according to claim 1, characterized in that said at least one suspension or separator means (6) is formed by one or more groups of bristles. 4.- Method for electropolishing metallic parts in floating electrical contact, according to claim 1, characterized in that said at least one suspension or separator means (6) is a mesh or one or more permeable and insulating fabrics. 5.- Method for electropolishing metal parts in floating electrical contact, according to claim 1, characterized in that said at least one means of suspension or separator (6) comprises a sleeve, bag or container with holes such that the pieces to be polished included in said sleeve cannot escape while the holes in the sleeve allow the passage of the electrolyte medium from the inside of the bag to the outside of the bag. 6.- Method for electropolishing metal parts in floating electrical contact, according to any of the preceding claims, characterized in that, in the electropolishing stage, the parts (1) are removed and / or turned by means of the movement of the cathode (5), while the anode (4) remains static. 7.- Method for electropolishing metallic pieces in floating electrical contact, according to any of claims 1 to 5, characterized in that, in the electropolishing stage, the pieces (1) are removed and / or turned by means of the movement of the anode (4), while the cathode (5) remains static. 8.- Method for electropolishing metal parts in floating electrical contact, according to any of claims 1 to 5, characterized in that, in the electropolishing stage, the parts (1) are removed and / or turned by means of the movement of the anode (4) and the cathode (5). 9.- Method for electropolishing metallic pieces in floating electrical contact, according to any of claims 1 to 5, characterized in that, in the electropolishing stage, the pieces (1) are removed and / or turned by means of the movement of the electrolytic medium (3) with said pieces (1) submerged therein, while both the anode (4) and the cathode (5) remain static. 10.- Method for electropolishing metal parts in floating electrical contact, according to any of claims 1 to 5, characterized in that, in the electropolishing stage, the parts (1) are removed and / or turned by means of the movement of the suspension or separator means (6). 11.- Electropolishing device (100, 100', 100”) for electropolishing metal parts in floating electrical contact, comprising: - a container (7) suitable for containing the electrolytic suspension (3) and capable of incorporating the piece or pieces (1) to be polished submerged in it; - a piece of metal or other conductive material constituting the anode (4) incorporated in the container (7) so that it is totally or partially submerged in the electrolytic suspension (3); and - a piece of metal or other conductive material constituting the cathode (5) that is in contact with the electrolytic suspension (3) of the container and that can be connected to an electrical power supply, is characterized in that, incorporated between the cathode (5) and the electrolytic suspension (3) of the container (7), it also comprises one or more separators (6) of insulating material, which keep the pieces (1) isolated from direct contact with the anode (4) or the cathode (5), which separators (6) have permeable free spaces (6a) that allow part of the electrolytic suspension (3) to pass through to make contact with the anode (4) or the cathode (5) and close the circuit. 12.- Electropolishing device, according to claim 10, characterized in that the separators (6) have a structure based on points, protuberances and other irregular shapes, at least on their contact surface with the electrolytic suspension (3), which define a minimum contact area with the pieces (1). 13.- Electropolishing device, according to claim 11, characterized in that the separator or separators (6) are made up of groups or brushes of bristles, mesh, or one or several permeable and insulating fabrics. 14.- Electropolishing device, according to claim 11, characterized in that the suspension or separator means (6) comprises a sheath, bag or container with holes such that the pieces to be polished included in said sheath cannot escape while the holes in the sheath allow the passage of the electrolyte medium from the inside of the bag to the outside of the bag. 15.- Electropolishing device according to any of claims 10 to 13, characterized in that, in a section of the device (100) where the cathode (5) moves and the anode (4) remains static, the container (7) with the electrolytic suspension (3) and the anode (4) is a fixed body of grooved annular configuration on which a carousel-shaped structure (9) rotates with metallic heads, which act as a cathode (5), and which are arranged radially hanging from it, which heads are covered with bristle brushes that fit into the grooved annular body acting as a separating element (6) between the cathode (5) and the pieces (1) incorporated therein submerged in the electrolytic suspension (3).

16. Electropolishing device according to any of claims 10 to 13, characterized in that, in a portion of the device (100') where the cathode (5) remains static and the anode (4) moves, the container (7) in which the electrolytic suspension (3) is incorporated, where the pieces (1) to be polished are immersed, is formed by a fixed tray whose bottom base constitutes the cathode (5) and in it are fixed, as a separating element (6), a plurality of bristles that completely cover said bottom, there being in the upper part of the container (7) a mobile string of bars that form the anode (4) and that, attached to an upper support (14), move along the tray, from one end to the other of the same, to remove the pieces (1). 17.- Electropolishing device, according to any of claims 10 to 13, characterized in that, in a section of the device (100") where the anode (4) and the cathode (5) are moving, the container (7) with the electrolytic medium (3) in which the pieces (1) to be polished are immersed is a rotating drum, which rotates on its axis and inside which it incorporates a plate fixed integrally to its inner wall acting as an anode (4), as well as a head that defines the cathode (5) and which, in turn, rotates inside the container (7) an angled shaft (16) to which it is connected by the opposite end, this cathode head (5) being covered with a bristle brush that acts as a separator (6) to prevent direct contact with the pieces to be polished (1).

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