CZ287944B6 - Galvanization process of making metal coating layers and apparatus for making the same - Google Patents

Abstract

The proposed galvanization process of making metal coating layers is characterized in that, the object to be subjected to galvanization is suspended within a space and electrolyte is supplied to the surface intended for galvanization by nozzles forming an anode, under pressure and in directed flow, whereby the nozzles change continuously their position with respect to the galvanized surface according to segmentation thereof. Each nozzle has electrically controlled voltage for maintaining current density at a predetermined value. The apparatus for carrying out the invented process consists of a supporting stool (3) with an eccentric (9) drive (6) secured thereto. The eccentric (9) drive (6) is coupled with a hollow plate (10), on which there is fastened at least one nozzle (11) passing through a swinging mounting arranged in a plate (12) being fixedly attached to the stool (3) and parallel to the hollow plate (10), whereby the stool (3) is coupled with an eccentric (8) having a drive (5) secured to a plate (2), on which there is fastened an eccentric (7) with a drive (4) attached to a main supporting plate (1). The hollow plate (10) is connected with a flexible tube (13) being connected with a pump (14), whose suction is connected to an electrolyte tank (15) that is interconnected with an electrolyte collecting tank (16), whereby each nozzle (11) is interconnected with the anode through a conductor (17) in which a current meter (18) is connected. The current meter (18) is connected with the input of an evaluation and control unit (21) whose output is connected with a voltage control element (19), while the object forming a cathode and intended for making metal coating layer thereon is slidably suspended on a load-supporting structure (23).

Description

Method for the galvanic formation of metal layers and apparatus for carrying out the method

Technical field

BACKGROUND OF THE INVENTION The present invention relates to a method and apparatus for the galvanic formation of metal layers, particularly on rugged manufacturing and internal surfaces of cavities that are difficult to access.

BACKGROUND OF THE INVENTION

Previously known methods of electroplating of complicated shaped objects and inner surfaces of cavities are realized by immersing the object from the galvanizing bath, sometimes during forced electrolyte flow. The requirements for the technical parameters of the formed layers are considerable and the known methods do not sufficiently meet them. It is mainly the uniformity of the layer thickness, homogeneity, absence of defects, eg hydrogen bubbles, adhesion of the layer to the surface of the metal-plated object, constant physical and mechanical properties of the layer.

Large-sized galvanoplastic products are obtained, for example, by using a rotational rocking of the product during the formation of the metal layer. This procedure is particularly suitable where it is necessary to place the anode in the cavity. The device for the realization of this method solves the invention of Czechoslovak. Certificate No. 261577.

Plating of the internal cavities is associated with considerable difficulties, especially in those cases where the outer surface of the product is not to be metallized, as is the case, for example, with the bore of internal combustion engine cylinders. This case is solved by the invention of MS. No. 250487, consisting of a housing made of electrically insulating material into which a component to be plated is inserted and an electrode placed in a cavity of the component and slidable into the housing, the housing mounted on the support structure having flow holes into the cavity through which the electrolyte washing the cavity walls is blown.

Plating of the inner surface of tubes of different diameters and lengths is solved, for example, by the invention. Author's Certificate No. 252647 for a fixture consisting of a carrier with at least one flexible liner in which split jaws are attached to fix the upper end of a pipe that is attached at its lower end in a clamp, fastened with the carrier on a pole to which the negative terminal is connected electric current. The positive terminal is connected via a collector to a bolt-shaped anode located in the tube cavity, on both ends of which there are insulating plugs with holes for electrolyte passage. The lower switchboard is connected to the lower end of the anode and is fixed by a vertical conductive bar to the collector.

All these technologies are performed when the product is immersed in a bath. An exception is the narrowly specialized case of metallization of the inner surface of a pipe according to the invention. No. 252647, where the electrolyte is circulated by means of pumps through a metallized tube suspended vertically. Further, a method is known in which a metal-plated article is placed in a sheath forming an equidistant surface with the surface of the article and the gap formed between the article and the sheath creating a flow of electrolyte through the pump and thereby accelerating the formation of metallization.

The plating of articles not immersed in the galvanizing bath is known from U.S. Pat. No. 4,029,555, which describes the plating of small, slightly shaped parts forming a continuous strip. The cathode-forming strip moves through the chamber in a plane perpendicular to the stable anode-forming nozzles and the part to be metallized is sprayed with the nozzles under pressure. The nozzles forming a straight line on the lance have a constant distance from the component belt during operation.

U.S. Pat. No. 4,427,520 discloses a device for electroplating relatively small, slightly shaped parts joined into a strip which is simultaneously on one or both sides

The electrolyte is sprayed with a plurality of nozzles, the metallized strip forming a cathode, the anode nozzles. In the process, the belt moves in one direction and the nozzles forming the straight line are stationary and practically perpendicular to the plane of the belt. The diameter of the nozzles, their distance from the metallized surface, the electrolyte flow rate are preset such that the cone formed by the electrolyte equally covers the metallized surface and is constant during the process.

These known nozzle spraying technologies are primarily applicable to the mass production of small parts, but do not allow the plating of larger to very large surfaces.

SUMMARY OF THE INVENTION

The above-mentioned drawbacks are largely eliminated by the method for the galvanic formation of the metal layers 15 according to the invention, which is characterized in that the electrolyte is fed to the metallized surface by at least one nozzle simultaneously carrying out at least two circular movements. In the first movement, the axis of the nozzle describes a conical surface whose axis is perpendicular to the plane of the second and each subsequent circular movement. The apex angle of the conical surface is adjusted optimally according to the height transitions of the metallized surface.

The current density on the plating surface is maintained at a preset value individually for each nozzle. For this purpose, an evaluation and control electronic device is provided, to which the corresponding current values are continuously fed, the variations of which are caused by height transitions on the metallized surface and, consequently, by changing the distance of the nozzle orifice from the surface.

The device for the galvanic formation of metal layers consists of a support stool on which is mounted an eccentric drive for the first circular movement. In this case, the eccentric is rigidly connected to the hollow plate to which at least one nozzle is resiliently connected, passing through a pivot bearing in the plate fixedly mounted on a support stool parallel to the hollow plate.

The stool is coupled to the eccentric for the second circular motion and the eccentric is connected to a drive mounted on the plate to which the eccentric for the third circular motion is mounted with the drive connected to the main support plate. A flexible tube is connected to the hollow plate connected to the discharge of the pump, the suction of which is connected to the electrolyte tank connected to the collection tank. Each nozzle 35 is connected to the anode by a conductor to which the meter is connected by a current connected to the input of the control and evaluation block, the output of which is connected to the voltage control element. The object intended to form the metal layer forming the cathode is slidably suspended in air on the support structure.

Overview of the figure in the drawing

The invention is explained in more detail in the drawing, which schematically illustrates a device for galvanically forming metal layers.

DETAILED DESCRIPTION OF THE INVENTION

Example 1

A copper layer was created on the model of the articulated heater. An acidic solution of copper sulfate with sulfuric acid and brighteners was used as the electrolyte. The anode voltage ranged from 20 to 45 V and the current density was predetermined and maintained at 2.5 A / dm ² . The electrolyte was fed through one nozzle of 3.0 mm diameter made of 55 titanium under a pressure of 100 kPa. The distance of the nozzle from the metallized object varied from 25 to

-2GB 287944 B6 up to 50 mm. Two eccentrics were used to move the nozzle. After a 7 hour process, a uniform 0.5 mm thick copper layer with a purity of 99.8% was obtained.

Example 2

A copper layer was formed on the surface of the rugged radiator with height transitions up to 20 mm. The electrolyte composition and operating parameters were the same as in Example 1. The electrolyte was fed through 20 nozzles 3.0 mm in diameter, 15 mm apart. The distance of the nozzles from the metallized surface was 20 to 60 mm. The movement of the nozzles was induced by three eccentrics with different speeds. After 12 hours of process a uniform copper layer with a thickness of 0.6 mm was formed.

The apparatus for carrying out the method according to the invention consists of a support stool 3, on which is mounted an electric motor 6 driving for the first circular movement eccentric 9 fixedly connected to the hollow plate W. On the hollow plate 10 the nozzles 11 are flexibly connected. mounted on the support stool 3, parallel to the hollow plate 10. The support stool 3 is rigidly connected to the eccentric 8 for the second circular motion, which is driven by an electric motor 5 supported by the plate 2. The eccentric 7 for the third circular motion, driven by the electric motor 4 mounted on a main support plate 1, which is pivotably supported on the support structure. The hollow plate 10 is connected by a flexible tube 13 to the discharge of the pump 14, the suction of which is connected to the electrolyte tank 15 connected to the electrolyte collection tank 16. Each nozzle 11 is connected separately to the anode by a conductor 17 into which an electric meter 18 and a voltage control element 19 are inserted. The meter 18 is connected by a conductor 20 to an input to the evaluation and control block 21, where the current values are continuously transmitted. The output of the evaluation and control block 21 is connected by a conductor 22 to a voltage regulating element 19. The object intended to form the metal layer is slidably hinged on the beam 23.

Industrial applicability

The method and apparatus for the galvanic formation of metal layers according to the invention are intended for use in the field of galvanic deposition of metals on large objects and very complex shapes to obtain a uniform layer of deposited metal.

Claims (2)

PATENT CLAIMS A method of galvanically forming metal layers by supplying an electrolyte through a nozzle to a metallized surface positioned in air, the nozzles being connected to a positive pole and a metallized surface to a negative pole, and a relative movement is formed between the nozzles and the surface. at least one nozzle simultaneously carrying out at least two circular movements, wherein in the first movement the nozzle describes a conical surface whose axis is perpendicular to the plane of the second and each other circular movement and the apex angle of the conical surface is set according to the height transitions of the metallized surface and current density on the metallized surface, it is maintained at a preset value for each nozzle individually by an evaluation and control electronic device 15, to which the respective current values are continuously transmitted, the changes of which are induced by the height passages on the metallized surface and consequently by changing the distance of the nozzle orifice from the surface. Device for carrying out the method according to claim 1, characterized in that it comprises a support 20 stool (3) on which is mounted the drive (6) of the eccentric (9) for the first circular movement of the nozzle (11), the eccentric (9) being connected to the hollow plate (10), on which at least one nozzle (11) extending in a swinging manner in the plate (12) mounted on the stool (3) is parallel to the hollow plate (10), the stool (3) is connected to the eccentric ( 8) for the second circular movement and the eccentric (8) is connected to a drive (5) mounted on the plate (2) on which the eccentric (7) for the third circular movement 25 is attached with a drive (4) connected to the main support plate (1) ), wherein a flexible tube (13) connected to the discharge of the pump (14) is connected to the hollow plate (10), the suction of which is connected to the electrolyte tank (15) connected to the collection tank (16) while each nozzle (11) is connected with an anode conductor (17) to which a current meter (18) connected to the control input is connected and an evaluation block (21), the output of which is connected to the voltage regulating element (19), while the cathode forming object 30 to form the metal layer is slidably hinged to the support structure (23).