JPS59136494A - Plating method for inner surface of hollow body - Google Patents

Abstract

PURPOSE:To apply excellent plating onto the inner surface of a hollow body, by sealing both ends of the hollow body into which an electrode is inserted with covers through which both ends of the electrode liquid-tightly thrust, and circulating a plating solution through an inlet provided at one cover and an outlet provided at the other cover. CONSTITUTION:A hollow body 10 is supported with a stand 11, and an electrode 12 is inserted into said hollow body 10. Thereafter, covers 13, 13' are attached to both ends of the hollow body 10, and the parts of the hollow body 10 connected to the covers 13, 13' are liquid-tightly sealed. Lead wires 12 for applying an electric current are connected to the projected parts of the electrode 12 at its both ends. Thereafter, a plating solution inside a tank 15 for a plating solution is circulated in the course of an opening 13b provided at the cover 13 the interior of the hollow body 10 an opening 13b' provided at the cover 13' by a circulating pump 16. At the same time, an electric current is applied for a predetermined time while holding the electrode 12 as an anode and the hollow body 10 as a cathode, to form a plating layer on the inner surface of the hollow body 10.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial application field The present invention has great effects on the method of forming a plating layer on the inner surface of a hollow object, especially in the inner surface layer-t-1 of a long hollow object. Concerning how to demonstrate.

Prior Art Conventionally, when plating the inner surface of a hollow object such as a pipe, the first
(As shown in this figure, the hollow object 1 is used as the cathode, and the inner surface of the hollow object (
The soluble @electrode 2 inserted at an equal distance from the other electrode is used as an anode, and is immersed in the plating solution in the processing tank 3 to form a plating layer on the inner surface of the hollow object. A method was adopted to do so.

澾→ Problems to be solved by the invention However, the above method requires a large treatment tank if the hollow object becomes long (Konarudame, exfoliation and degreasing, Tunke Sanko, Doike Menki, Hon. The amount of processing liquid and rinsing water used for plating, etc. is extremely large, and as a result, a large amount of waste liquid is generated and the area occupied by the equipment is also increased.

■Since the hollow object is completely immersed in the plating solution, there is a risk that the plating layer may wrap around the outer surface, and to prevent this, it is necessary to seal the outer surface of the hollow object.

■In order to obtain a plating layer with a good surface condition, it is necessary to reliably remove the V° gas generated during the plating process, but even if the plating solution in the processing tank is forced to circulate, the inner surface of the hollow It is not possible to sufficiently remove the V-space bubbles that are locally attached to the surface of the tube, and therefore, it is easy to cause damage to the surface.

■Several types of electrodes are required depending on the nature of the processing solution used from degreasing to main plating, and they must be replaced each time. As a result, there are many drawbacks and problems, such as low work efficiency and low power consumption.

(Means for Solving the Problems) This invention has been made in view of the above points, and uses a hollow object whose inner surface is plated as a part of a processing liquid container. Both ends of the hollow body are sealed with a lid through which both ends of the laryngeal tube pass through in a liquid-tight manner, and then the inside of the hollow body is plated by inserting the 9 (rj) opening into one lid and using the opening in the other lid as an outlet. By performing the plating process while circulating the liquid, the drawbacks and problems described in items (1) to (4) above are solved.

It should be noted that the means for solving the drawback (2) described later is preferable in terms of further increasing the economic effect and simplifying the work, but it is not an essential requirement of the present application.

The method of the present invention will now be described in detail with reference to the accompanying drawings.

First, as shown in FIG.
0 using a stand 11 etc., and 41 in it.
Pass 412. Next, cover 13.1i is attached to both ends of the hollow object 1o.
to seal the joint between the hollow object and the lid liquid-tight.

In addition, (the end of the box 12 is connected to the hole 1 provided in the can lid 1d, 13)
3a, 13a' to the outside in a liquid-tight manner.
At the same time as connecting the event lead 1 house 14 (@the box 12 is held in place by passing it through the hole in the lid). is circulated through the hollow body 10 by the circulation pump 16, and at the same time, the liquid is passed through the tube 12 as an Im pole and the hollow body 10 as a cathode for a predetermined period of time, thereby stripping the inner surface plating layer of the hollow body.

At this time, it is preferable that the hollow body 10 is arranged diagonally or vertically as shown in the figure, and the plating solution is focused using the opening 13b provided in the lower lid as an inlet and the opening 13b provided in the second lid as an outlet. In this way, the gas bubbles attached to the inner surface of the hollow object are effectively removed by the flow of the liquid and the buoyant force. However, according to the present invention, even if the hollow object is arranged horizontally, the force bubbles can be removed by speeding up the flow of the plating solution.

In addition, the groove 41f12 may be a soluble one, but if an insoluble porcelain made of titanium material is plated in-house,
Is it OF such as 1 finger of copper release, pickling, base plating, and water washing? Even when processing, just replacing the plating liquid tank 16
There is no need to replace the 4'ft and 12's.

In addition to being rod-shaped, the pole 12 may be plate-shaped depending on the cross-sectional shape of the hollow object, and may be inserted into the hollow object after the lid 13 is attached.

Note that the liquid seal at the end of the hollow object may be achieved by employing, for example, a structure as shown in F.

That is, a ring 17 as shown in FIG.
is fixed using a set screw 18, and a plurality of tightening bolts 19 parallel to the axis of the hollow object are attached to this ring. On the other hand, the lids ia and is are provided with flanges 13C and 113C facing the rings 17 and 17, respectively, and by fixing the bolts 19 to these 7 radii and tightening them with nuts, the lid i3. i3 is pressed against the end face of the hollow object. At this time, it is desirable to interpose a seal packing 20 at the joint between the can lid and the hollow object, and also to interpose a seal member 21 between the lid and the cover 12.

Examples of the present invention will be described below.

[Example] A lid for liquid sealing was installed at both ends of a long stainless steel pipe with an inner diameter of 50 mm and a length of 500 mm.

- On the other hand, the anode uses an insoluble (electrode) coated with a new plating of titanium.While circulating the plating solution from F upwards, wash with water/vomit and degrease/suiko/electrolytic acid/suiko. / After nickel F base plating / water droplet /, a flow density 3 A / dm2
, Matte copper sulfate plating was applied by applying electricity for 30 minutes. that time,
The lid was fixed to the hollow object from beginning to end, and the anode was not replaced.

The plating liquid tank used at that time was 1001EI1001
Is the amount of plating solution 2.5J for EIIX100? Met. Furthermore, the entire work up to completion of the plating process took 60 minutes.

As a result, a plated layer with a stable surface condition and a uniform thickness could be obtained.

[Comparative example]

In order to confirm the effects of the present invention, matte copper sulfate plating was applied to 7R4 plates made of the same material and of the same thickness using the conventional method shown in FIG. The plating liquid tank at that time was 100m x 100m.
With yaX l'o OOx, 91 plating solutions were required. The total work time required 120 minutes, and the resulting plating layer was locally roughened due to air bubbles when energized under the same conditions, and the outer surface was slightly roughened. According to , because the plating solution flows only into the inside of the hollow object, only a small amount of processing solution and rinsing water is required, and the accompanying equipment can be small, and the plating layer does not wrap around the outside of the hollow object. .

Moreover, since the plating solution is circulated, any air bubbles generated during plating are effectively removed, and the surface treatment condition is stabilized. Removal of D° gas bubbles will be more reliable if the hollow object is peeled off or placed vertically.

Furthermore, if you use an insoluble electrode for each step, there is no need to replace the electrode even if you perform the operations of screw removal, degreasing, waxing, base plating, and main plating continuously. 1.Economy and work efficiency are further improved.

[Brief explanation of drawings]

Fig. 1 schematically shows the conventional plating method (Fig. 2 shows the plating method of the present invention, Fig. 3 shows Fig. 2 JI [-I
FIG. 3 is a cross-sectional view taken along the If line. 10...Hollow object, 12...1 pole, 13.13...
Lid, 15... Plating liquid tank, 16... Circulation pump, 2
0... Seal packing, 21... Seal part (O. Patent applicant: Ninpan Electric Industry Co., Ltd.

Claims (4)

[Claims] (1) Both ends of the hollow object with the electrode inserted inside are liquid-tightly sealed with a lid that penetrates through the ends of the electrode liquid-tightly sealed, and then the internal electrode is used as the anode and the hollow object is used as the cathode. The opening provided in one of the lids is used as an inlet, and the opening in the other lid is used as an outlet to circulate the plating solution, forming a plating layer on the inner surface of the hollow object. A method for plating the inner surface of hollow objects. (2) The method for plating the inner surface of a hollow object according to claim (1), characterized in that the can lid is moored to a ring fixed to the outer periphery of the hollow object, and the end of the hollow object is sealed with liquid. (3) The inward plating method for a hollow object according to claim (1) or (2), characterized in that an insoluble electrode is used as the electrode. (4) Any one of claims (1) to (3), characterized in that the hollow object is arranged diagonally or vertically, and the plating solution is flowed from the lower side toward the two sides. A method for plating the inner surface of a hollow object as described in Crab.