RU2282684C1 - Plant for electroplating inner surface of articles - Google Patents

Abstract

FIELD: electroplating, namely apparatuses for coating complex shape inner surfaces of articles, for example inner surfaces of bent small cross section tubes with use of electrolyte containing noble metal.

SUBSTANCE: plant includes first and second baths filled with electrolyte; pump; unit for changing direction of electrolyte flow; members for supplying and discharging electrolyte; holder of electroplated article. First bath is filled with electrolyte containing noble metal and it is connected with positive pole of electric current source. Second bath is connected with negative pole of electric current source. Unit for changing direction of electrolyte flow is connected with pump arranged in first bath. One ends of members for supplying and discharging electrolyte are connected with unit for changing direction of electrolyte flow; their other ends are connected with article suspended in second bath.

EFFECT: possibility for providing highly uniform coating of complex inner surfaces of small cross section articles at minimum consumption of electrolyte containing noble metal, simplified making up of electrolyte.

3 cl, 1 dwg

Description

The invention relates to electroplating, in particular to devices for coating complex internal surfaces of products, and may find application, for example, in cases for coating the internal surfaces of curved pipes of small cross section using an electrolyte containing a precious metal.

A device for nickel plating the inner surface of pipes (A. M. Yampolsky, V. A. Ilyin. Quick reference. Electroplating. 2nd edition. L. Engineering, 1972, p. 138, Fig. 31), adopted as a prototype .

The known device has two baths for collecting electrolyte, a pump for supplying electrolyte, a hard anode.

Using this device, it is impossible to ensure uniform coverage of complex internal surfaces of products of small cross section.

The present invention solves the problem of ensuring uniform coverage of complex internal surfaces of products of small cross section.

To achieve this technical result, the installation for galvanic coating of the inner surface of products, containing the first and second bathtubs filled with electrolyte, and a pump, is equipped with means for changing the direction of electrolyte flow, elements for supplying and discharging electrolyte and a holder for the coated product, while the first bathtub is filled with electrolyte, containing precious metal, and connected to the positive pole of the current source, the second bath is connected to the negative pole of the current source, means for changing Ia electrolyte flow connected with the pump, which is placed in the first bath, the electrolyte supply and discharge elements are connected at one end with means for changing the direction of flow of the electrolyte, and the other ends - with a coating product, which is suspended by the holder in the second bath.

In this case, the means for changing the direction of flow of the electrolyte is made in the form of a slide switch.

Elements of supply and removal of electrolyte are made in the form of hoses.

The drawing shows the proposed installation.

The electroplating installation comprises a first bath 1 and a second bath 2, the first bath 1 being filled with an electrolyte 3 containing a precious metal and connected to the positive pole of a direct current source (not shown), the second bath 2 filled with any other conductive electrolyte 4 (without any precious metal) and is connected to the negative pole of the DC source, a centrifugal pump 5 which is connected to the first bath 1 and serves to supply electrolyte 3 through the pipe 6 to the spool switch 7, hoses 8 under water and electrolyte discharge 3, connected at one end to a slide valve, and at the other ends are sealed by means of connecting elements 9 to an article to be coated inside, for example, a curved pipe 10. The apparatus also includes an article holder including a rod 11 fixed to a second bath 2, and pendants 12.

To drain the electrolyte 3 into the first bath 1, a nozzle 13 is provided at the slide switch 7.

Installation works as follows.

The pipe is suspended on suspensions 12 to the rod 11 in the second bath 2 with electrolyte 4. Hoses 8 are connected to the pipe 10 by connecting elements 9. The baths 1 and 2 are energized and the centrifugal pump 5 is turned on. The pump through the pipe 6, slide switch 7 and one of of hoses 8, the electrolyte 3 from the first bath 1 is fed into the internal cavity of the pipe 10. Through another hose 8 and the pipe 13, the electrolyte 3 is discharged into the bath 1.

During the coating process, the slide switch 7 changes the flow direction of the electrolyte 3, which ensures uniform coverage of the entire internal cavity of the pipe.

After the estimated time, the installation is turned off, the product covered inside is removed. The process is then repeated.

The use of the invention will allow for uniform coating of the inner surfaces of small products such as bent pipes with precious metals in small-scale production. It will also allow to cover products with a minimum consumption of electrolyte containing precious metal, as it is located in a separate bathtub, which is not connected with the dimensions of the product to be coated, and therefore can be made with a significantly low capacity. In addition, the correction of the density of the electrolyte in a small bath is much easier to produce than in a large bath.

Claims (3)

1. Installation for galvanic coating of the inner surface of products, containing the first and second bathtubs filled with electrolyte, and a pump, characterized in that it is equipped with means for changing the direction of electrolyte flow, elements for supplying and discharging electrolyte and a holder for the coated product, while the first bathtub is filled an electrolyte containing a precious metal, and connected to the positive pole of the current source, the second bath is filled with an electrolyte not containing a precious metal, and connected to a negative yusom current source means for changing the flow of the electrolyte is connected to a pump which is placed in the first bath, the electrolyte supply and discharge elements are at one end connected to the means of changing the electrolyte flow direction, and the other ends - with a coating product, which is suspended by the holder in the second bath. 2. Installation according to claim 1, characterized in that the means for changing the direction of flow of the electrolyte is made in the form of a slide switch. 3. Installation according to claim 1, characterized in that the elements of the supply and removal of electrolyte are made in the form of hoses.