JP5688596B2 - Zinc or zinc alloy barrel electroplating method - Google Patents

Description

  The present invention relates to a barrel plating method, and more particularly to a zinc or zinc alloy barrel electroplating method for small parts such as bolts and screws.

Japanese Patent Laid-Open No. 49-130 (Patent Document 1) describes a method and an apparatus for rotating a barrel in a plating tank. The plating apparatus described here includes a barrel that accommodates an object to be plated, a cathode that is inserted into the barrel and is in contact with the object to be plated, and an anode that is disposed outside the barrel.
FIG. 6 is a cross-sectional view schematically showing an example of a barrel plating apparatus used in a conventional barrel electroplating method. As shown in FIG. 6, a conventional barrel electroplating apparatus 100 has a barrel 104 rotatably supported in a plating tank 102, and an object to be plated W is accommodated in the barrel 104. Moreover, the cathode 106 is arrange | positioned in the barrel 104 so that the to-be-plated thing W accommodated in the barrel 104 may be contacted. On the other hand, the anode 108 is disposed outside the barrel 104 in the plating tank 102. When performing plating, a voltage is applied between the anode 108 and the cathode 106 while rotating the barrel, and a current flows between the anode 108 and the workpiece W in contact with the cathode 106.

JP-A-49-130

  When electroplating is performed using a barrel plating apparatus described in JP-A-49-130, an object to be plated is brought to a cathode potential by coming into contact with a cathode inserted into the barrel. Therefore, when the number of objects to be plated in the barrel is small, the contact between the cathode and the objects to be plated or the contact between the objects to be plated cannot be sufficiently ensured, and some objects to be plated may cause poor conduction. There is a problem. If a current-carrying failure occurs even in one of a large number of plated products, a bipolar phenomenon occurs, which causes plating failure, adhesion failure, and uneven plating, and a good plating film cannot be obtained. Moreover, when there are many to-be-plated objects, the total amount of current required for plating will become large, and the bath voltage will also become high. Since this large current flows from the anode outside the barrel through the hole provided in the wall surface of the barrel, there is a problem that the current concentrates there and abnormal deposition of plating metal called scoring occurs.

  In particular, the uniform electrodeposition type non-cyanide alkaline zinc plating and zinc alloy plating, which are widely used in recent years, tend to cause bipolar phenomenon due to the strong adsorption of plating additives, resulting in poor contact on the object to be plated. In such a case, there is a problem that the plating is not deposited and the adhesion failure occurs remarkably.

Therefore, the present invention makes it possible to obtain a uniform plating film that does not easily cause adhesion failure such as non-plating, blistering, and peeling regardless of the amount of the object to be plated, and that is free from burns and gloss defects on the plating film. It aims to provide a barrel electroplating method that can be used.
In particular, an object of the present invention is to provide a barrel electroplating method capable of efficiently plating zinc or a zinc alloy on an object to be plated.

In order to solve the above-mentioned problems, the present invention is a barrel electroplating method in which zinc or zinc alloy plating is applied to the surface of a metal, and the step of accommodating an object to be plated in a barrel provided with a cathode on an inner wall surface And a step of immersing the barrel containing the object to be plated in the plating solution, and applying a voltage between the anode and the cathode arranged apart from the inner wall surface of the barrel in the barrel and rotating the barrel, rocking, or to vibrate, rotate the anode, possess swing, or a step of vibrating the anode, the hole current flows into the object to be plated is formed from the anode, and to the anode of the object to be plated It is characterized by being covered with an anode cover that prevents accidental contact .

In the present invention configured as described above, the object to be plated accommodated in the barrel is electrically connected to the cathode provided on the inner wall surface of the barrel. The barrel is rotated, rocked, or vibrated by a barrel drive. The anode is disposed in the barrel so as to be separated from the inner wall surface of the barrel, and is rotated, rocked, or vibrated by the anode driving unit.

  According to the present invention configured as described above, since the cathode is provided on the inner wall surface of the barrel, the conduction between the object to be plated and the cathode is reliably ensured, and the anode is disposed in the barrel. Since it is rotated, oscillated, or oscillated by the drive unit, an excessive increase in bath voltage can be prevented. Thereby, regardless of the amount of the object to be plated, a good plating film can be obtained.

In the present invention, the voltage applied to the anode is preferably applied via an anode electrical contact immersed in the plating solution.
According to the present invention configured as described above, since the anode electrical contact is immersed in the plating solution, the configuration of the entire barrel plating apparatus can be simplified.

In the present invention, the voltage applied to the anode is preferably applied via an anode electrical contact made of titanium.
According to the present invention configured as described above, even if the contact portion of the anode electrical contact is immersed in the plating solution, the contact resistance of the contact can be kept low.

In the present invention, preferably, the anode has a cylindrical or columnar shape.
According to the present invention configured as described above, the anode can be easily formed.
In the present invention, the anode is preferably an insoluble anode or a soluble anode.
In the present invention, preferably, the cathode is formed of a conductive material.

In the present invention, preferably, the cathode is made of copper, gold, iron, nickel, stainless steel, titanium, carbon, or a conductive resin.
In the present invention, the plating solution preferably flows into or out of the barrel through a number of holes formed in the cathode provided in the barrel.
According to the present invention thus configured, the object to be plated can be immersed in the plating solution by immersing the barrel in the plating solution tank.

In this invention, Preferably, to-be-plated object contacts the cathode formed so that the whole inner wall surface of a barrel might be covered.
According to the present invention configured as described above, conduction between the object to be plated and the cathode can be made more reliable.

In this invention, Preferably, to-be-plated object is mixed by the triangular prism-shaped mountain-shaped baffle plate arrange | positioned in a barrel.
According to the present invention configured as described above, the objects to be plated in the barrel can be more effectively mixed, so that the formed plating layer can be made more uniform.

In the present invention, the barrel is preferably made of polyvinyl chloride, polypropylene, or polytetrafluoroethylene .

According to the barrel electroplating method of the present invention, regardless of the amount of the object to be plated, it is difficult to cause poor adhesion such as non-plating, blistering, and peeling, and uniform plating with no burns or gloss defects on the plating film. A coating can be obtained.
In particular, according to the barrel electroplating method of the present invention, zinc or a zinc alloy can be efficiently plated on an object to be plated.

It is a front view of the barrel plating apparatus used for the barrel electroplating method of this invention. It is a left view of the barrel plating apparatus used for the barrel electroplating method of this invention. It is a right view of the barrel plating apparatus used for the barrel electroplating method of this invention. It is sectional drawing of a barrel. It is a figure which shows the mechanism of the anode electrical contact which provides a positive voltage to an anode. It is sectional drawing which shows typically the structure of the barrel plating apparatus used for the conventional barrel electroplating method.

Next, preferred embodiments of the present invention will be described with reference to the accompanying drawings.
The present invention relates to a barrel in which an anode is disposed in the center of a barrel, a cathode is disposed on a barrel inner wall surface, the anode is rotated, rocked, or vibrated, and the cathode on the barrel wall surface is rocked, rotated, or vibrated. Zinc and zinc alloy plating using an electroplating device, improving the cathode contact so that the product to be plated is always energized, reducing the bath voltage by reducing the distance between the electrodes, and preventing current concentration This is based on the knowledge that the current density can be made uniform and a uniform plating film can be obtained. In addition, the present invention can improve the anode current efficiency and prevent the increase of the bath voltage by plating while rotating the anode installed in the barrel, further enhancing the uniformity of the film and the effect of preventing burns. This is based on the knowledge that high current density work is possible.

  First, with reference to FIG. 1 thru | or FIG. 5, the barrel plating apparatus used in order to implement the barrel electroplating method of this invention is demonstrated. 1 is a front view of the barrel plating apparatus, FIG. 2 is a left side view, and FIG. 3 is a right side view. FIG. 4 is a cross-sectional view of the barrel. FIG. 5 is a diagram showing a mechanism of an anode electrical contact for applying a positive voltage to the anode.

  As shown in FIGS. 1 to 3, the barrel plating apparatus 1 includes two frame plates 2a and 2b, a barrel 4 supported so as to be swingable with respect to the frame plate, and provided with a cathode, and the barrel 4 A voltage is applied between the cathode 6 and the anode 6 disposed on the central axis of the oscillation, the barrel driving motor 8 serving as the barrel driving unit, the anode driving motor 10 serving as the anode driving unit, and the anode 6. Power supply unit 11.

  The barrel plating apparatus 1 is a barrel electroplating apparatus using an insoluble anode made of iron. This apparatus accommodates small articles such as bolts and screws in a barrel 4 and immerses the barrel plating apparatus 1 in a plating solution in a plating solution tank to a predetermined position. Next, while starting the anode driving motor 10 and rotating the anode 6, the barrel 4 is swung at a predetermined cycle, and a current is passed between the anode 6 and the cathode provided on the barrel 4, thereby The small article in 4 is subjected to zinc or zinc alloy plating.

In the present embodiment, the power supply unit 11 is a pulse power supply unit that applies a pulsed voltage between the cathode and the anode 6.
The frame plates 2a and 2b are two flat plates formed of an insulator, and are connected in parallel by three connecting rods 2c, 2d, and 2e. The frame plates 2a and 2b are provided with bearings for supporting the barrel 4 so as to be swingable between them. In the present embodiment, the frame plates 2a and 2b are made of polyvinyl chloride.

  As shown in FIG. 4, the barrel 4 includes two large-diameter barrel gears 12 disposed at both ends, a thin metal plate 14 disposed so as to connect these, a positive electrode cover 16, and a negative terminal 18. And baffle plate 20.

  The thin plate 14 is bent into a concave shape to form a barrel having a half octagonal cross section, and an object to be plated (not shown) is accommodated inside this. The thin plate 14 is a copper plate provided with a large number of small holes, and its inner surface functions as a cathode provided on the inner wall surface. In use, the plating solution flows in or out through many small holes in the thin plate 14.

  In the present embodiment, the cathode is formed by forming the barrel itself from a conductive material. However, as a modification, the barrel is formed of an insulator such as polyvinyl chloride, polypropylene, or Teflon (registered trademark). A conductive cathode plate may be attached to the inner wall surface of the barrel. In the present embodiment, the thin plate 14 is made of copper, but the barrel 4 may be made of gold, iron, nickel, stainless steel, titanium, carbon, or conductive resin as another metal.

  The anode cover 16 is formed of five plate-like members and is disposed so as to cover the generally lower half of the anode 6 disposed in the barrel 4. The anode cover 16 prevents accidental contact of the objects to be plated with the anode 6 when the number of objects to be plated is large. A large number of small holes are formed in the anode cover 16, and a current flows from the anode to the object to be plated through these small holes. In the present embodiment, the anode cover 16 is made of polyvinyl chloride.

The cathode terminal 18 is an elongated metal plate extending from both sides of the thin plate 14, and is connected to the negative terminal of the power supply unit 11 (FIG. 1).
The baffle plate 20 is a prismatic member disposed at the corner of the folded thin plate 14, and the baffle plate 20 forms a triangular cross-section mountain inside the barrel 4. The baffle plate 20 forms a mountain on the inside of the barrel 4 so that the object to be plated is well mixed when the barrel 4 is swung.

  As shown in FIGS. 1 to 3, the anode 6 is a stepped shaft-shaped iron cylinder having a small diameter at both ends, and the both ends extend through the frame plates 2a and 2b. Yes. Thereby, the anode 6 is supported rotatably with respect to the frame plates 2a and 2b. An anode driving gear 22 is attached to one step of the anode 6. As a modification, the anode 6 may be formed hollow and cylindrical. Moreover, the anode 6 can also be comprised by attaching the soluble or insoluble anode material to the surface of the hollow cylinder formed with the plastic and / or metal so that replacement | exchange is possible. In addition to iron, nickel, zinc or the like can be used for the anode. Preferably, dimple-like irregularities of the golf ball are formed on the surface of the anode 6.

  As shown in FIG. 3, the anode driving motor 10 disposed on the upper portion of the barrel plating apparatus 1 rotates and drives the anode driving gear 22 through transmission gears 24a, 24b, and 24c attached to the frame plate 2b. To do. Thereby, the anode 6 is rotationally driven.

  On the other hand, as shown in FIG. 2, the barrel driving motor 8 disposed in the upper part of the barrel plating apparatus 1 drives the barrel gear 12 via transmission gears 26a and 26b attached to the frame plate 2a. Further, the barrel gear 12 is provided with protrusions 12a and 12b. When the barrel gear 12 rotates about the anode 6, the protrusions 12a and 12b are moved, and thereby the rod 28 rotatably attached to the frame plate 2a is rotated. The tip of the rotated rod 28 switches the microswitches 30a and 30b arranged on both sides thereof on or off. That is, in FIG. 2, when the barrel gear 12 is rotated counterclockwise, the protrusion 12a pushes the lower end portion of the rod 28 leftward, and the rod 28 is rotated clockwise. As a result, the upper end of the rod 28 pushes the micro switch 30a to turn it on. When the micro switch 30a is turned on, the rotation of the barrel driving motor 8 is reversed, and the barrel gear 12 is rotated clockwise.

  When the barrel gear 12 is rotated clockwise, the protrusion 12b pushes the lower end portion of the rod 28 to the right, and the rod 28 is rotated counterclockwise. As a result, the upper end of the rod 28 pushes the micro switch 30b to turn it on. When the micro switch 30b is turned on, the rotation of the barrel driving motor 8 is reversed, and the barrel gear 12 is rotated counterclockwise again. By repeating the above operation, the barrel 4 is swung over an angle range of about 90 °.

Next, the configuration of the anode electrical contact portion will be described with reference to FIG.
As shown in FIG. 5, the anode electrical contact portion includes a rod-like anode terminal 32, a coil spring 34 that urges the anode terminal 32, and a fixed-side contact member 36 that is a fixed-side member that contacts the anode 6. And an insulating sleeve 38 through which the anode terminal 32 passes, and a spring adjustment bolt 40 for adjusting the urging force of the coil spring 34. In use, the anode electrical contact portion is immersed in the plating solution, and the anode 6 is slid with respect to the stationary contact member 36.

  The anode terminal 32 is a stepped shaft with a thin upper portion, and the upper end thereof is connected to the plus terminal of the power supply unit 11, and the fixed contact member 36 is attached to the lower end. The thinned upper portion of the anode terminal 32 is passed through the coil spring 34, and the stepped portion of the anode terminal 32 is engaged with the lower end of the coil spring 34.

The stationary contact member 36 is made of titanium and is screwed to the lower end of the anode terminal 32. The bottom surface of the stationary contact member 36 is formed in a cylindrical surface so as to slide with a small contact area with the small diameter portion of the anode 6. The anode 6 is rotated while the bottom surface of the stationary contact member 36 that is the stationary side of the anode electrical contact and the iron anode 6 that is the movable side of the anode electrical contact are in contact. As a result, a current flows from the positive terminal of the power supply unit 11 to the anode 6 through the anode terminal 32 and the stationary contact member 36.
As a modification, the fixed side contact member 36 and / or the movable side of the anode electrical contact can be made of a corrosion-resistant metal material such as titanium or a titanium alloy.

  The insulating sleeve 38 is a pipe made of polyvinyl chloride, and is arranged so as to cover the anode terminal 32 and the coil spring 34. The spring adjusting bolt 40 is a bolt made of polyvinyl chloride with a bore formed in the center. And is formed so as to be screwed onto the upper portion of the insulating sleeve 38. The spring adjustment bolt 40 is disposed such that the anode terminal 32 passes through the bore and the tip of the spring adjustment bolt 40 presses the upper end of the coil spring 34. For this reason, by rotating the spring adjustment bolt 40, the force for compressing the coil spring 34 changes, and the force for pressing the stationary contact member 36 against the anode 6 can be adjusted.

Next, an example of the barrel electroplating method of the present invention using the barrel plating apparatus 1 will be described.
First, small articles such as, for example, iron bolts and screws, which are objects to be plated, are placed in the barrel 4 of the barrel plating apparatus 1. Thereby, each to-be-plated object is electrically connected with a cathode through the other to-be-plated object which is in direct contact with the inner wall surface of the barrel 4 or in contact with the inner wall surface of the barrel 4. In addition, as a base | substrate which is a to-be-plated object, metals and alloys, such as various metals, such as nickel and copper, these alloys, or aluminum which performed zinc substitution treatment other than iron are mentioned. Examples of the object to be plated include various shapes such as bolts, nuts, washers, small press articles, rectangular parallelepipeds, columns, cylinders, and spherical objects.

  After putting an object to be plated into the barrel 4, the barrel plating apparatus 1 is immersed in a plating tank containing a plating solution up to a predetermined position. Specifically, the barrel plating apparatus 1 is plated so that the barrel 4 and the anode 6 are completely immersed in the plating solution, and the barrel driving motor 8 and the anode driving motor 10 are positioned above the liquid surface of the plating solution. Immerse in the liquid. Examples of the zinc and zinc alloy plating solution used in the present invention include an acidic bath such as a sulfuric acid bath, an ammon bath, and a potassium bath, and an alkaline bath such as an alkali non-cyan bath and an alkali cyan bath. In particular, in galvanization, it is preferable to use an alkali non-cyanide bath (Dipsol NZ-200, NZ-100, NZ-87 bath).

  Examples of the zinc alloy plating include zinc-iron alloy plating, zinc-nickel alloy plating, and zinc-cobalt alloy plating. In particular, a zinc-nickel alloy plating bath having a nickel eutectoid rate of 12 to 18% from an alkali non-cyanide bath is preferable.

  Next, the barrel driving motor 8 and the anode driving motor 10 are started. The anode 6 is rotated at about 50 to 100 rpm around the central axis of the anode 6 by the driving force of the anode driving motor 10. On the other hand, the barrel gear 12 of the barrel 4 is rotationally driven at a rotational speed of about 1 rpm by the driving force of the barrel driving motor 8 and is swung so that the rotational direction is reversed every time it is rotated about 90 °. .

Further, for example, a pulsed current of 50 A-10 V is caused to flow between the anode terminal 32 and the cathode terminal 18 by the power supply unit 11. Thereby, the current flows through the anode terminal 32, the fixed contact member 36, the anode 6, the plating solution, the object to be plated, and the cathode (the inner wall surface of the barrel 4). The current flowing between the anode terminal 32 and the cathode terminal 18 may be a direct current. The bath temperature depends on the plating solution, but is generally 15 to 50 ° C, preferably 25 to 35 ° C. The current density is 0.1 to 15 A / dm ² , preferably 0.5 to 5 A / dm ² . During plating, a plating solution in the barrel 4 is preferably circulated using a filter (not shown).

  Furthermore, by swinging the barrel 4, the object to be plated in the barrel 4 is mixed, and a uniform plating layer is formed on the surface of the object to be plated. Further, the baffle plate 20 provided in the barrel 4 promotes the mixing of the objects to be plated in the barrel 4 and forms a more uniform plating layer. Further, since the inner wall surface of the barrel 4 constitutes the cathode, the number of the objects to be plated is small, and even when the objects to be plated are not in contact with each other, the conduction of the objects to be plated to the cathode is ensured. The occurrence of bipolar phenomenon is prevented. Furthermore, since the anode cover 16 is disposed around the anode 6, even when the number of objects to be plated is large, direct contact of the objects to be plated with the anode 6 is prevented.

Further, since the anode 6 immersed in the plating solution is rotated, a flow of the plating solution is always generated around the anode 6 and the bath voltage (voltage between the anode terminal 32 and the cathode terminal 18) is abnormally increased. Can be prevented. Furthermore, since the anode 6 is disposed in the barrel 4 at a position relatively close to the cathode, and the object to be plated is disposed so as to surround the anode 6, the exposed area of the anode 6 with respect to the object to be plated increases, Black deposits due to concentration and burning are prevented.
After a predetermined time, the application of voltage by the power supply unit 11 is stopped, and the barrel plating apparatus 1 is pulled up from the plating bath to finish the plating operation. Although zinc and zinc alloy plating of arbitrary thickness can be formed by this method, it is preferable that the thickness of plating is 1 micrometer or more, More preferably, it is 5-25 micrometers.

Next, an example in which plating was actually performed using the barrel electroplating method of the present invention will be described.
Example 1
Using a barrel plating apparatus 1 (20 kg barrel) in which the cathode was a copper plate and the anode was iron, galvanizing was applied to M8 bolts. The input amount of bolts was varied between 1 and 20 kg. First, as a pretreatment, alkaline degreasing, alkaline electrolytic cleaning, and pickling were performed. The plating bath used was 8 g / l zinc, 120 g / l caustic soda, and 10 ml / l NZ-200S (manufactured by Dipsol Co., Ltd.).
The plating conditions were a current density of 1 A / dm ² , a plating time of 40 minutes, and a bath temperature of 25 ° C. As shown in Table 1, as a result of the galvanization, a glossy galvanized film could be obtained at any input amount of 1 to 20 kg.

Example 2
Using a barrel plating apparatus 1 (20 kg barrel) in which the cathode was a copper plate and the anode was nickel, the M8 bolt was galvanized. The input amount of bolts was varied between 1 and 20 kg. First, as a pretreatment, alkaline degreasing, alkaline electrolytic cleaning, and pickling were performed. Moreover, the composition of the plating bath was 8 g / l of zinc, 1.6 g / l of nickel, 130 g / l of caustic soda, and 5 ml / l of IZ-252S (manufactured by Dipsol Co., Ltd.).
The plating conditions were a current density of 1 A / dm ² , a plating time of 50 minutes, and a bath temperature of 25 ° C. As shown in Table 2, as a result of the galvanization, a glossy galvanized film could be obtained at any input amount of 1 to 20 kg.

Comparative Example 1
Next, as a comparative example, the result of galvanizing using the conventional barrel plating apparatus shown in FIG. 6 will be described.
Using a barrel plating apparatus (20 kg barrel) shown in FIG. 6 with copper as the cathode and iron as the anode, the M8 bolts were galvanized. The input amount of bolts was varied between 1 and 20 kg. First, as a pretreatment, alkaline degreasing, alkaline electrolytic cleaning, and pickling were performed. The plating bath used was 8 g / l zinc, 120 g / l caustic soda, and 10 ml / l NZ-200S (manufactured by Dipsol Co., Ltd.).
The plating conditions were a current density of 1 A / dm ² , a plating time of 40 minutes, and a bath temperature of 25 ° C. As shown in Table 3, as a result of galvanization, a glossy galvanized film was obtained at an input amount of 20 kg, but plating was not yet applied at an input amount of 1 kg and 5 kg, and an input amount of 10 kg. Then, plating was uneven.

Comparative Example 2
Using a conventional barrel plating apparatus (20 kg barrel) shown in FIG. 6 with copper as the cathode and nickel as the anode, the M8 bolts were galvanized. The input amount of bolts was varied between 1 and 20 kg. First, as a pretreatment, alkaline degreasing, alkaline electrolytic cleaning, and pickling were performed. Moreover, the composition of the plating bath was 8 g / l of zinc, 1.6 g / l of nickel, 130 g / l of caustic soda, and 5 ml / l of IZ-252S (manufactured by Dipsol Co., Ltd.).
The plating conditions were a current density of 1 A / dm ² , a plating time of 50 minutes, and a bath temperature of 25 ° C. As shown in Table 4, as a result of galvanization, a glossy galvanized film could be obtained at an input amount of 20 kg, but plating was not yet applied at an input amount of 1 kg and 5 kg, and an input amount of 10 kg. Then, plating was uneven.

  As described above, in Examples 1 and 2, since the cathode and the object to be plated are always in contact with each other even when the input amount of the bolt as the object to be plated is small, unplated or defective plating is Although not generated, in Comparative Examples 1 and 2 using a conventional barrel plating apparatus, when the input amount of the object to be plated is small, the object to be plated and the cathode are not sufficiently in contact with each other. Defects such as adhesion and poor plating occurred. This is presumably because a bipolar phenomenon occurred in an object to be plated that was not sufficiently connected to the cathode.

  According to the zinc or zinc alloy barrel electroplating method of the embodiment of the present invention, there is no significant influence on the amount of the object to be plated, there is no adhesion failure such as non-plating, blistering, peeling, etc. A uniform plating film without gloss failure can be obtained. Thus, since this invention can perform high quality zinc plating and zinc alloy plating efficiently, it can be expected to be used in a wide range of applications such as automobile parts and household appliance parts.

  As mentioned above, although preferable embodiment of this invention was described, a various change can be added to embodiment mentioned above. In particular, in the above-described embodiment, the anode is rotated in the barrel. However, the barrel plating apparatus may be configured such that the anode is swung or vibrated.

  Furthermore, in the above-described embodiment, the barrel is swung or rotated, but the barrel plating apparatus may be configured such that the barrel is vibrated.

DESCRIPTION OF SYMBOLS 1 Barrel plating apparatus used for barrel electroplating method of this invention 2a, 2b Frame board 2c, 2d, 2e Connecting rod 4 Barrel 6 Anode 8 Barrel drive motor (barrel drive part)
10 Anode drive motor (anode drive)
DESCRIPTION OF SYMBOLS 11 Power supply part 12 Barrel gear 14 Thin plate 16 Anode cover 18 Cathode terminal 20 Baffle plate 22 Anode drive gear 24a, 24b, 24c Transmission gear 26a, 26b Transmission gear 28 Rod 30a, 30b Micro switch 32 Anode terminal 34 Coil spring 36 Fixed side contact member 38 Insulating sleeve 40 Spring adjusting bolt 100 Conventional barrel electroplating apparatus 102 Plating tank 104 Barrel 106 Cathode 108 Anode W W

Claims (12)

A barrel electroplating method in which zinc or zinc alloy plating is applied to the surface of a metal,
Accommodating the object to be plated in a barrel provided with a cathode on the inner wall;
Immersing the barrel containing the object to be plated in a plating solution;
In the barrel, a voltage is applied between the anode and the cathode arranged apart from the inner wall surface of the barrel, and the barrel is rotated, oscillated, or oscillated, and the anode is rotated and oscillated. or a step of vibrating the possess,
Zinc or zinc characterized in that the anode is covered with an anode cover that is formed with a hole through which current flows from the anode to the object to be plated and prevents accidental contact of the object to be plated with the anode Alloy barrel electroplating method.   The zinc or zinc alloy barrel electroplating method according to claim 1, wherein the voltage applied to the anode is applied via an anode electrical contact immersed in a plating solution.   The zinc or zinc alloy barrel electroplating method according to claim 1 or 2, wherein the voltage applied to the anode is applied via an anode electrical contact made of titanium.   The zinc or zinc alloy barrel electroplating method according to any one of claims 1 to 3, wherein the anode has a cylindrical or columnar shape.   The zinc or zinc alloy barrel electroplating method according to any one of claims 1 to 4, wherein the anode is an insoluble anode or a soluble anode.   The zinc or zinc alloy barrel electroplating method according to any one of claims 1 to 5, wherein the cathode is formed of a conductive material.   The zinc or zinc alloy barrel electroplating method according to any one of claims 1 to 6, wherein the cathode is made of copper, gold, iron, nickel, stainless steel, titanium, carbon, or a conductive resin.   The zinc or zinc according to any one of claims 1 to 7, wherein the plating solution flows into or out of the barrel through a number of holes formed in a cathode provided in the barrel. Alloy barrel electroplating method.   The zinc or zinc alloy barrel electroplating method according to claim 1, wherein the object to be plated is in contact with a cathode formed so as to cover the entire inner wall surface of the barrel.   The zinc or zinc alloy barrel electroplating method according to any one of claims 1 to 9, wherein the object to be plated is mixed by a triangular prism shaped baffle arranged in the barrel. The zinc or zinc alloy barrel electroplating method according to any one of claims 1 to 10, wherein the barrel is made of polyvinyl chloride, polypropylene, or polytetrafluoroethylene .   The zinc or zinc alloy barrel electroplating method according to any one of claims 1 to 11, wherein the voltage applied between the cathode and the anode is changed in a pulse shape.

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