JPS5914560B2 - Barrel plating device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a barrel plating device used for plating small-sized mechanical parts and accessories.

Conventionally, in this type of barrel plating device, a hexagonal cylindrical drum containing the object to be plated and having a large number of small holes in the peripheral wall is immersed in a plating bath, and a drum 10 is placed inside the drum. Devices are known in which a cathode lead wire is introduced and anodes are placed on both sides of the drum.

In this case, the drum rotates slowly (from 3 to 5, p, m)
As a result, the covered object is also rotated and subjected to a gentle vibration (approximately 0.1 to 1 A/d771").1
5. Although such conventional barrel plating devices have the advantage of being able to plate many small-sized parts at once, they have the following problems.

Namely, the first plating time is several times longer than that of the hooking method, the second plating layer becomes more uneven in thickness, the third plating layer has incomplete parts and the yield is poor, and the fourth method is high voltage. Because of the low current and high liquid resistance, the bath temperature rises during plating and the electrodeposition conditions change, and it is difficult to remove the gas generated in the drum. 25 Because of these problems, the fields of application of conventional barrel plating have been limited to decorative plating of accessories, needles, screws, etc., and base plating, where thickness unevenness is not a big concern.

This invention was made for the purpose of eliminating the various drawbacks of the conventional barrel plating device 3 as described above, and the present invention is aimed at eliminating the various drawbacks of the conventional barrel plating device 3 as described above. an inner cylindrical body for accommodating an object with a cover 35, which is coaxially provided in the outer cylindrical body so as to form a void therein, and has a large number of small holes in the peripheral wall and both ends through which plating liquid passes; a drum consisting of; a cathode member introduced into the inner cylindrical body and brought into contact with the object to be plated; means for rotating the drum; and an infusion means for passing plating liquid into the drum. The present invention provides a barrel device characterized by the following.

Hereinafter, the present invention will be explained based on specific examples shown in the drawings.

In the figure, reference numeral 1 denotes a drum, and as shown in FIG. 2, it consists of an outer cylinder 2 with a circular cross section and an inner cylinder 3 with a hexagonal cross section, and a gap 4 is formed between these cylinders. The outer cylinder 2 is made of a non-conductive material such as vinyl chloride resin,
An anode layer 5, for example titanium, is applied to its inner wall. Reference numeral 6 is a contact point of the anode, which has a ring shape and is electrically connected to the anode layer. A large number of small holes 7 (1 to 5 m in diameter) are provided in the peripheral wall of the inner cylinder 3 to allow the plating liquid to pass through.The inner surface of the inner cylinder 3 is coated with an insoluble anode layer, such as platinum plating. In that case, a breathable non-conductive material 8, such as nylon cloth (thickness 1 to 10!NO), is applied on the inside to insulate the cathode. are provided so that the lattice members 9a,
A pair of cathode lead wires 10 are introduced into the inner cylindrical body 3 through the center of the inner cylindrical body 3 and come into contact with a plating object 11 housed within the inner cylindrical body 3.

The drum 1 is pivotally supported at both ends by support members 12 and can be rotated by a motor 13.
That is, the drum 1 is rotated at an appropriate speed by the plurality of gears 14, 15, and 16. Pipes 17 and 18 are provided at both ends of the drum 1, respectively, for guiding the plating liquid into the drum 1 and discharging it from the drum 1. Furthermore, a truncated conical branch pipe 19 is provided on the plating liquid introduction side of the drum 1 to promote the spouting effect of the plating liquid from the small hole 7 provided in the peripheral wall of the inner cylinder 3. is taken into account. The operation for plating using the barrel plating device having such a configuration will be described below.

First, as shown in FIG. 3, the plating liquid discharge side of the barrel plating device is raised by the device tilting mechanism 20.

In this case, the connection between the pipe 18 and the drum 1 is removed, and the fitting between the lattice 9b and the inner cylindrical body 3 is removed. Next, apply an appropriate amount of the covering material 11,
After housing the pipe 1 in the inner cylinder 3, the grid 9b is attached to the inner cylinder 3 again, the barrel plating device is returned to the horizontal position, and the pipe 1 is
8 is connected to drum 1. Next, the pump 22 is started to introduce the plating liquid into the drum 1 through the pipe 17, and the drum 1 is rotated by the motor 13. At the same time, the contact 6 and the cathode lead wire 9 are energized. The plating liquid sent from the pump 22 is divided by the flow dividing pipe 19, and a portion passes through the gap 4 and is jetted from the small hole 7 to the center of the drum 1. This jet of plating liquid constantly supplies new plating liquid to the object 21 to be plated. Therefore, operation at high current density is possible, and the plating solution is uniformly stirred, thereby eliminating uneven electrodeposition and eliminating the risk of poor plating. In addition, the plating liquid flowing through the center of the drum 1 removes the gas generated by electrolysis and the jet plating liquid whose metal ion concentration has been reduced by the electrolysis toward the pipe 18, and removes the plating liquid near the center of the drum 1. The stirring effect of the surface portion of No. 11 is enhanced. After the plating operation is completed, the fourth
As shown in the figure, by raising the liquid feeding pipe 17 side and removing the grid 9b, the stuck object 11 can be easily taken out.

Note that since this device uses an insoluble anode, as electroforming progresses, the pH of the electrolyte and the gold layer ions may decrease. In such a case, the necessary adjustment reagent may be supplied to the preliminary tank 23. In the apparatus according to the present invention, the rotational speed of the drum 1 is 5 to 10 rpm. p. A suitable rotation speed is about m. If the rotation speed is too slow, it will cause uneven electrodeposition, and if it is too fast, it will cause poor plating.

The current density can be several tens of times higher than that of the conventional method, and is about 1 to 5 A/DmZ for precious metal plating, and about 5 to 20 A/d for copper. The flow velocity of the plating liquid sent to the drum is 0.5 to 5 m/Se at the center of the drum.
About cl is preferable. The number of cathode lead wires introduced into the drum is not particularly limited, and may be appropriately determined depending on the volume of the inner cylinder. Note that the means for tilting the barrel plating device is not limited to those shown in FIGS. 3 and 4, and any other means may be selected as appropriate. Since the barrel plating device according to the present invention adopts a method of feeding the plating liquid into the barrel tank with a rapid flow (0.5 to 5 m/Sec), the barrel plating device is No need to soak it in.

Therefore, the plating solution does not have to be pumped out when the barrel plating tank is pulled up, unlike in the prior art, and loss of the plating solution can be prevented. In addition, a portion of the plating liquid is flowed into the center of the barrel tank (drum), and a portion of the plating liquid is ejected from the peripheral wall of the drum, ensuring a sufficient supply of metal ions to the object to be plated. V1, which enables operation at high current density, provides sufficient agitation of the plating solution, and provides a uniform thickness of the plating layer. Further, the parallel flow of the plating liquid flowing through the center of the drum promotes the removal of tired plating liquid and generated gas, so that the plating efficiency can be improved. In addition, the anode is placed on the inner wall of the drum to reduce the distance between the electrodes, which allows the electrolyte to flow rapidly, reduces liquid resistance, enables operation at high current density, and prevents defects such as plating. can be achieved. In addition, according to this invention, the plating speed can be increased 5 to 20 times as compared to the above-mentioned conventional method. In addition, according to the present invention, since the anode area can be increased, a large amount of plating can be performed at one time. The types of plating to which this invention can be applied are gold, silver, platinum,
Rhodium, chromium, nickel, etc.

In addition to various types of decorative plating, it can also be applied to functional plating that requires dimensional accuracy. Example 1 Acid gold plating (potassium gold cyanide 201/t) was applied to a necktie pin made of solid wood using a barrel plating device shown in FIGS. 1 to 4 with a drum capacity of 1500 Cfit.
1 citric acid 307/t1 potassium citrate 190y/t
) was applied.

Note that the tie pins have a surface area of 0.1 dm, and 40 of them were housed in the inner cylinder 3 for plating.The electrodeposition conditions were a flow rate of 1 m/m/cm at the center of the cylinder 3. Sec
．． Drum rotation speed 5r. p. rn. The current density was 2 A/d (efficiency 95%), the pH was 5.2, the bath temperature was 60° C., and the plating thickness was 3 μm. Comparing the results with the conventional method, the current density was approximately 20 times higher, the plating time was significantly shortened to 20 minutes and 10 seconds, and (2) there were no plating defects as in the conventional method. The yield was 100%.

Example 2 Using the barrel plating device shown in FIGS. 1 to 4 with a drum volume of 2000 cTi1, glossy nickel plating was applied to the base of small screws (length 1.5 m7!L) of camera parts made of solid material. (Nickel sulfate 3007/t1 Nickel chloride 70v/t1 Boric acid 40f/t) was carried out.

The electrodeposition conditions were a flow rate of 0.8 m/sec at the center of the cylinder 3 and a drum rotation speed of 8 r. p. m1 current density 12A/Dm" (efficiency 97%), PH4O, bath temperature 60℃, plating thickness 10μ
It was hot. The plating time was approximately 12 times that of the conventional method (approximately 1 A/Dm"), and the plating time was also significantly shortened to 4 minutes.

Electrodeposited? However, a uniform plated layer could be obtained without defective products with incomplete nickel deposition or with no protruding electrodeposition.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a barrel plating device according to the present invention;
Figure 2 is a sectional view taken along the - line in Figure 1, Figures 3 and 4.
This figure is a side view showing how the barrel plating device shown in FIG. 1 is used. The symbols shown in the figures will be explained below. DESCRIPTION OF SYMBOLS 1... Drum, 2... Outer cylinder, 3... Inner cylinder, 4... Gap, 5... Anode layer, 7... Small hole, 8...
... Breathable non-conductive layer, 9a, 9b... Grid plate, 10.
... Cathode lead wire, 11... Covering material, 13...
Motor, 14, 15, 16...Gear, 17, 18...
・Pipe, 19... Diversion pipe, 20... Incline mechanism, 2
2...Pump.

Claims (1)

[Scope of Claims] 1. An outer cylindrical body having an anode layer coated on its inner wall, and an outer cylindrical body provided coaxially within the outer cylindrical body so as to form a gap between the anode layer and the inner wall of the cylindrical body. an inner cylindrical body for accommodating an object to be plated and having a large number of small holes through which a plating solution passes; a cathode introduced into the inner cylindrical body and brought into contact with the object to be plated; A barrel plating device comprising: a member; a means for rotating the drum; and an infusion means for passing a plating liquid into the drum. 2. Claim 1, characterized in that the inner cylinder has an insoluble anode layer formed on its inner surface, and further an insulating layer with the cathode part made of a breathable non-conductive material. barrel plating device. 3. Claim 1, wherein at least one end of the inner cylindrical body is composed of a removable perforated plate.
Alternatively, the barrel plating device described in item 2. 4. The barrel plating device according to claim 1, 2 or 3, wherein a truncated conical branch pipe is provided at the end of the inner cylinder on the plating liquid introduction side. 5. Claims 1, 2, 3 or 5, wherein the outer cylinder has a circular cross section, the inner cylinder has a polygonal cross section, and the corners thereof are in close contact with the inner wall of the outer cylinder. Barrel plating device according to item 4.