JPS6160158B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for automatically plating a large number of small parts uniformly and efficiently using centrifugal force.

Conventionally, hook-type, basket-type, and barrel-type means have been used to plate small parts, such as machine screws, washers, and watch parts. However, since these rely on their own weight to bring small parts into contact with the cathode, it is difficult to obtain a sufficient supply voltage and it is difficult to achieve the required plating thickness. Another problem was that small parts came into uneven contact with the cathode, resulting in uneven plating shadows and uneven film thickness. This is particularly noticeable in the case of chrome plating, and it is extremely difficult to uniformly and efficiently apply chrome plating to the thickness required for small parts.

To solve this problem, for example, a small drum with a cathode on the inner periphery and an anode in the center is installed inside a large rotating drum, and small parts are placed in the small drum and pressed against the cathode by the centrifugal force generated by the rotation. be. This is effective in that a sufficient supply voltage can be obtained and the necessary plating thickness and uniform plating can be achieved. However, in this method, the volume of the small drum is limited due to the structure in which the rotating small drum is installed within the rotating large drum, and plating is performed only on a part of the inner wall of the rotating small drum. Only a small number of small parts can be plated. If a large number of small parts were to be processed at once, there would be a problem in that the apparatus would need to be large-scale. On the other hand,
During the plating process, metal ions in the plating solution gradually decrease, and the temperature of the plating solution rises, reducing plating efficiency.
Since a small drum has a small capacity, its influence is large.
If you try to circulate the liquid to solve this problem,
Since both the large and small drums rotate independently, there was a problem in that the structure became large and complicated. Furthermore, it is not only necessary that the liquid be circulated in a large capacity, but also that the contact point with the cathode can be varied by rolling of small parts.

The present invention relates to an automatic plating method and apparatus for small parts, and is intended to solve the above-mentioned problems of the conventional methods. In other words, the purpose is to be able to process a large amount of small parts at once, to stir and roll the small parts so that the point of contact with the cathode changes, to achieve uniform plating without shadows, and to have a relatively simple structure. To provide a method and device for automatic plating of small parts, which enables circulation of plating, replenishes decreasing metal ions, prevents rise in liquid temperature, and improves plating efficiency.

The present invention will be explained below by means of illustrated embodiments.

A is a rotatable drum, which has a cylindrical shape with a bottom that becomes smaller in diameter toward the bottom, and has an inclined inner circumferential wall 1 as a cathode. 2 is the lid, and there is an insulating plate 3 on the top of drum A.
A short cylindrical portion 5 is provided to protrude upward from the central hole 4. 6 is an anode member,
It has a cylindrical shape with a smaller diameter toward the bottom, and is attached to the inner peripheral wall 1 of the drum A toward the outer periphery of the lower surface of the lid 2.
It is placed vertically with a space between it. The lower edge of the anode member 6 is attached to the end of a horizontal crosspiece 7 in the diametrical direction, and a bearing 9 for a stirring shaft 8, which will be described later, is provided in the center of the horizontal crosspiece 7.

Reference numeral 10 denotes stirring members, each of which has a vertically elongated plate shape with a side edge 11 that can fit along the inner circumferential wall 1 of the drum A with a small gap, and two stirring members are provided inside the drum A. That is, the stirring shaft 8 inserted downward from the cylindrical part 5 at the center of the lid 2
The lower part of the shaft 8 is pivotally supported by the bearing 9, a horizontal arm 12 extending in the diametrical direction is fixed to the lower end of the shaft 8, and vertical arms 13 extending upward between the inner circumferential wall 1 of the drum and the anode member 6 are provided on both sides of the horizontal arm 12. each provided with its vertical arm 1
The stirring member 10 is attached to the outer side of each of the stirrers 3 and 3, respectively. The stirring member 10, stirring shaft 8, horizontal arm 12, vertical arm 13, etc. are made of an electrically insulating material or are coated with an insulating coating.

Reference numeral 14 denotes a drum rotation motor, which is provided at the lower part of the machine frame 15 and is capable of rotating a shaft 17 at the center of the lower part of the drum A via a drive belt 16. 18
A motor for rotating the stirring member is provided at the upper part of the machine frame 15, and is capable of rotating the stirring member 10 via a belt 19 and a pulley 20 attached to the upper part of the stirring shaft 8. Note that the rotation speed of the stirring member 10 is different from the rotation speed of the drum A, and the rotation speed of the drum A is 200 r.
In the case of pm, it would be something like 210r.pm.

Reference numeral 21 denotes a cathode side contact, which contacts a part of the outer periphery of the shaft 17 at the bottom of the drum A and is electrically connected to the inner peripheral wall 1 of the drum. 22 is the anode side contact, and the upper machine frame 1
It is screwed downward from 5, and its lower end is in contact with an annular plate 23 provided on the top surface of the lid 2 to establish electrical conduction with the anode member 6 at the bottom of the lid 2.

24 is a liquid supply pipe for liquid circulation, 25 is a liquid discharge pipe, and the liquid supply pipe 24 is connected to an external tank 26.
It hangs down from above the center of drum A,
The liquid discharge pipe 25 is made to protrude laterally from above near the periphery of the drum A, and a side plate 27 surrounding the side of the drum A is used to drain the liquid that overflows due to the rotation of the drum A during plating.
It is designed to be received by the tank 26 and returned to the tank 26. 29
is a take-out stopper, 30 is a take-out port, 31 is a take-out lever,
32 is an input port.

In the above configuration, the stirring member 10 has a plate-like shape, but it may have a comb-like shape. Further, its rotational speed may be slower than the rotational speed of the drum A, unlike the above embodiment. The stirring shaft 8 may be rotated by using the motor 14 for rotating the drum instead of using a separate motor 18. In the figure, a indicates a small part to be plated, and b indicates a plating solution. Numeral 28 is a bolt for attaching and detaching the lid, which allows the lid 2 to be attached to the drum A in an insulated state. Although not shown, it is desirable that the tank 26 is provided with a cooler.

Next, the operating conditions and effects of the present invention will be explained using the above embodiments. In use, a small part a to be plated is placed in the drum A, a plating liquid B is supplied from the liquid supply pipe 24, and the drum rotation motor 14 and stirring member rotation motor 18 are rotated. And it is sufficient if the electrodes are energized.

As a result, the drum A rotates, and due to the centrifugal force, the internal small parts a are evenly scattered over the entire wide inner circumferential wall 1 of the drum A, and are strongly pressed against the inner circumferential wall 1, which is the cathode. Drum A at the same time
The inner plating liquid b also rises near the inner circumferential wall 1 of the drum A due to centrifugal force, and the anode member 6, the small parts a, and the inner circumferential wall 1, which is the cathode, become in the plating liquid b.
Therefore, a large number of small parts a are scattered over the wide inner circumferential wall 1 in a pressure-welded manner, and a large number of small parts a are plated at once under sufficient power supply voltage.

On the other hand, since the stirring member 10 rotates at a speed different from that of the drum A with a small gap between it and the inner peripheral wall 1 of the drum A, the stirring member 10 hits the small part a that is in pressure contact with the inner peripheral wall 1 and agitates it. do. Therefore, since the small part a rolls while being pressed against the inner peripheral wall 1 of the cathode, the contact point with the cathode changes and uniform plating is applied evenly.
The shadow of Metsuki will no longer appear.

Furthermore, a liquid supply pipe 24 and a liquid discharge pipe 25
As a result, the drum A is always replenished with new plating solution B, and the old solution is discharged and circulated. therefore,
The metal ions that decrease during plating are replenished, and the liquid temperature that rises due to heat radiation can also be lowered.
The plating coverage is improved, the plating speed can be increased, and the plating film thickness can be easily increased, so that the plating efficiency can be increased.

As is clear from the above, according to the automatic plating device for small parts of the present invention, the small parts can be pressed against the cathode using centrifugal force, and a sufficient supply voltage can be obtained, and the small parts can be attached all around the inner wall of the drum. It can press across the body, and can plate many times more at one time than conventional methods that use centrifugal force. Moreover, since the small parts are rolled by the stirring member, there is no plating shadow, and since the plating liquid is circulated, it has beneficial effects such as improved plating coverage and increased plating efficiency. It is something.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a cutaway front view of the main part of the device, and FIG. 2 is a cross-sectional plan view of the drum. Drawing code, A...Drum, a...Small parts, b
...Metting liquid, 1...Inner peripheral wall, 10...Stirring member, 26...Tank.

Claims (1)

[Claims] 1. A small part a to be plated is placed in a plating drum A having a bottomed cylindrical shape with the inner circumferential wall 1 as a cathode,
The drum A is rotated while the plating liquid b is circulated from the external tank 26, and the plating liquid b rises near the periphery due to centrifugal force.
An automatic plating method for small parts, in which the small part a is brought into pressure contact with the entire inner peripheral wall 1, and the small part a is plated by rolling on the inner peripheral wall 1 with a stirring member 10 having a rotation speed different from that of the drum A. 2 The anode member 6 is placed inside the rotating bottomed cylindrical drum A.
At the same time, the inner circumferential wall 1 of the drum A is used as a cathode, and a stirring member 10 is provided with a slight gap to the inner circumferential wall 1 so that it can rotate at a rotation speed different from that of the drum A. This automatic plating device for small parts is provided with a liquid supply pipe 24 for liquid circulation and a liquid discharge pipe 25 between an external tank 26.