JP3084631B1 - Plating method and plating equipment - Google Patents

Abstract

An object of the present invention is to provide a plating method and a plating apparatus which can provide a uniform plating finish on an object to be plated with less uneven plating. SOLUTION: A chain is arranged on one side of a plating treatment tank so as to mesh with a gear provided on one side of a barrel, and the chain is bypassed at a chromate treatment tank. A gear integrated with a power source separate from the chain is provided in a portion of the processing tank for chromate treatment in which the gears of the barrel should mesh with each other. This is a plating apparatus in which the barrel is rotated 1.3 to 3 times faster than the rotation and alternately repeats forward rotation and reverse rotation at regular time intervals.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates to a plating method and a plating apparatus.

[Prior art]

Conventionally, in performing zinc plating and chromate treatment on an object to be plated, a drum-shaped barrel containing the object to be plated is moved on a line to perform a pretreatment step,
In each of the zinc plating step, the chromate treatment step, and the post-treatment step, a method has been adopted in which the barrel is immersed in a liquid tank and rotated to plate the object to be plated.

When plating is performed by this method, the problem of uneven plating does not occur in the zinc plating step because the barrel is immersed in the liquid tank for a long time. However, in the chromate treatment step, plating time tends to be uneven because the immersion time of the barrel in the liquid tank is extremely short. This tendency is particularly remarkable when the object to be plated is a thin plate-like object having many flat portions.
It is inevitable that a plated product having uneven plating is obtained at a rate exceeding 0%.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a plating method capable of providing a uniform plating finish on an object to be plated with less uneven plating. SUMMARY OF THE INVENTION It is an object of the present invention to provide a plating apparatus which has a small plating unevenness and can give a uniform plating finish to an object to be plated.

[0005]

Means for Solving the Problems The present inventor has conducted various studies to solve the above-mentioned problems, and as a result, a pretreatment step,
In the galvanizing step, the chromate treatment step and the post-treatment step, the barrel containing the object to be plated is immersed in the liquid tank and rotated to perform plating on the object to be plated. The above object of the present invention is to increase the speed of the barrel by 1.3 to 3 times faster than the rotational speed of the barrel in a process other than the chromate treatment process, and to rotate the barrel so as to alternately rotate forward and backward at regular time intervals. Was found to be resolved. The present invention has been completed based on such findings.

That is, according to the present invention, a drum-shaped barrel containing an object to be plated is moved on a line,
In a method in which a barrel is immersed and rotated in a liquid tank in each step of a zinc plating step, a chromate treatment step, and a post-treatment step to perform plating treatment on an object to be plated, the rotational speed of the barrel in the chromate treatment step is changed to a chromate treatment step. The rotation speed of the barrel in the other process is 1.3 to 3 times higher, and the barrel is rotated by alternately repeating the forward rotation and the reverse rotation at regular time intervals to perform a chromate treatment on the object to be plated. Related to the plating method.

Further, the present invention is an apparatus for performing the above plating method, wherein one side of each processing tank in each of a pretreatment step, a zinc plating step, a chromate treatment step and a post-treatment step is provided. A chain is arranged so that a gear provided on one side of a drum-shaped barrel in which a material to be plated is stored meshes, and the chain is bypassed at a processing tank for chromate treatment. A gear integrated with a power source different from the chain is provided in a portion of the processing tank of the chromate treatment in which the gears should mesh with each other, and the rotation of the power source reduces the rotation of the barrel in a process other than the chromate treatment process. The present invention relates to a plating apparatus characterized in that the barrel is rotated by repeating forward rotation and reverse rotation alternately at a speed of 1.3 to 3 times and at regular intervals.

[0008]

In the present invention, the shape of the object to be plated is not particularly limited, and examples thereof include various shapes such as a cylindrical shape, a plate shape, and a spherical shape. The size of the object to be plated may be any size as long as it can be placed in a cylindrical container called a drum-shaped barrel used in the method of the present invention.

The plating step in the method of the present invention comprises a pretreatment step, a zinc plating step, a chromate treatment step, and a post-treatment step.

The pretreatment step includes a degreasing step, a pickling step, an electrolytic degreasing step, and the like. After each of these steps, a water washing step is provided in order to prevent the treatment liquid of each step from being mixed. The treatment tank for this washing step may be one tank,
It may be a tank. For example, after the degreasing step, it is preferable to provide two treatment tanks for the water washing step, after the pickling step, it is preferable to provide two treatment tanks for the water washing step, and after the electrolytic degreasing step, it is preferable to provide two treatment tanks. It is preferable to provide one tank.

In the galvanizing step, a plurality of, for example, 6 to
There are provided 20 plating baths, preferably 10 to 14 plating baths. After the galvanizing step, a water washing step and a nitric acid treatment step are provided. The treatment tank in the water washing step may be one tank or two tanks.

The chromate treatment step usually comprises one treatment tank. The chromate treatment step may be a gloss chromate treatment step or a colored chromate treatment step. Alternatively, the chromate treatment step may include two treatment tanks, a gloss chromate treatment tank and a colored chromate treatment tank.

The post-treatment step includes a water washing step, a hot water washing step, a drying step and the like. The treatment tank in the water washing step may be one tank or two tanks, but preferably two tanks.

The processing liquid in the processing tank in each of the above steps is not particularly limited, and may be the same as a conventional processing liquid. Further, the drying temperature and the drying time in the drying step may be the same as those in the related art. In the present invention, the drum-shaped barrel containing the object to be plated is moved on the line, and the barrel is immersed and rotated in the liquid tank in each of the pretreatment step, the zinc plating step, the chromate treatment step, and the post-treatment step. Then, the plating object can be plated.

More specifically, a chain moves in one direction on one side of the processing tank in each of the above steps, and a gear provided on one side of the barrel meshes with the chain to rotate the barrel. I have. The rotation speed of the barrel is 1
The moving speed of the chain and the number of gears provided on one side of the barrel are adjusted so that the rotation is 5 to 10 rotations per minute, preferably 7 to 8 rotations, particularly preferably about 7.5 rotations. The barrel immersed and rotated in the processing tank for each process for a certain period of time is lifted by a lifting machine such as a lift, moved to the next processing tank, and then lowered by a lifting machine such as a lift. A line is constructed such that the immersion and rotation process are performed for a certain period of time.

FIG. 1 is a schematic view of a plating process line according to the present invention. In FIG. 1, the chain is slowly moving in the direction from the pre-processing step to the post-processing step. The barrel at the top of the pretreatment step is lifted by a lift (not shown) and is in a moving state. The barrel in the galvanizing step is immersed in a galvanizing tank and is rotating. The rotation of the barrel in the galvanizing tank is achieved by rotating a gear provided on one side of the barrel according to the movement of the chain in which the gear meshes. As the processing proceeds, these barrels move to the right side in FIG. 1 while repeating lifting and lowering by a lift.

In the present invention, in the chromate treatment step, the chain gear is designed not to mesh with the barrel gear but to rotate the barrel gear by rotation by another power source. FIG. 2 is an enlarged view of a portion of a chromate treatment process of a plating process line according to the present invention.
As shown in FIG. 2, the chain is detoured at the processing tank for chromate treatment, and the portion where the gears of the barrel mesh is integrated with another power source, for example, a motor (not shown). A gear is provided.

In the present invention, the barrel immersed in the chromate treatment tank is rotated by transmission from a gear that is rotated by the rotational motion of another power source. The barrel immersed in the chromate treatment tank has a rotation speed of 1.3 to 3 times, preferably 1.5 to 2.5 times, the rotation speed of the barrel in another treatment tank.
It is particularly preferable to rotate at a speed of 1.8 to 2.2 times. For example, a barrel immersed in a chromate treatment tank usually rotates 10 to 20 times per minute, preferably 11 times.
The rotation is preferably 18 to 18 rotations, particularly preferably 15 rotations.
The direction of rotation is such that forward rotation (the same rotation direction as that of the barrel in the processing tank up to now) and reverse rotation are alternately repeated at regular intervals. These can be achieved by providing such a rotational movement to the power source. The time for the forward rotation and the reverse rotation is usually about 2 to 5 seconds, preferably about 3 seconds. The immersion time for the gloss chromate treatment is usually about 8 to 10 seconds, and the immersion time for the colored chromate treatment is usually about 15 seconds.

[0019]

According to the method of the present invention, it is possible to apply a uniform plating finish to an object to be plated with almost no plating unevenness. That is, in the method of the present invention, the occurrence rate of the product having uneven plating is less than 1%, which is extremely low, which is 1/20 of the occurrence rate of the product having uneven plating obtained by the conventional method. The above-described effects are also exhibited when the object to be plated is a thin plate-shaped object having many flat portions.

[0020]

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a plating process step line of the present invention.

FIG. 2 is an enlarged view of a part of a chromate treatment process in a plating process line of the present invention.

Claims (2)

(57) [Claims] 1. A drum-shaped barrel containing an object to be plated is moved on a line, and the barrel is immersed in a liquid tank in each of a pretreatment step, a zinc plating step, a chromate treatment step, and a post-treatment step. In a method of performing a plating process on an object to be plated by rotating, a rotating speed of a barrel in a chromate treatment process is set to be 1.3 to 3 times faster than a barrel rotational speed in a process other than the chromate treatment process, and the barrel is sequentially rotated at regular intervals. A plating method characterized in that a plating object is subjected to a chromate treatment by rotating a barrel by alternately repeating rotation and reverse rotation. 2. An apparatus for performing the method according to claim 1, wherein one side of each processing tank in each of a pretreatment step, a galvanizing step, a chromate treatment step, and a post-treatment step is provided. A chain is arranged so that a gear provided on one side of a drum-shaped barrel in which an object to be plated is stored is meshed, and the chain is bypassed at a processing tank for chromate treatment. A gear integrated with a power source separate from the chain is provided in a portion of the processing tank for chromate processing where the gears should mesh with each other, and the rotation of the power source causes the gear to rotate one time from the rotation of the barrel in steps other than the chromate processing step. 3. A plating apparatus characterized in that the barrel is rotated by alternately repeating forward rotation and reverse rotation three to three times faster and at regular time intervals.