JPH09279394A - Hanging jig for energization for surface treatment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to continuously execute anodic oxidation and coating by specifying the front end angle and front end diameter of the energizing contact part of a hanging jig to specific values and freely rotatably holding this energizing contact part. SOLUTION: The front end angle of the energizing contact part 1 of the hanging jig is specified to 10 to 70 deg. and the front end diameter thereof to <=3mm. The energizing contact part 1 is screwed in by a bolt 2 and an aluminum product 6 is held between the energizing contact part 1 and a product holding part 7. When the hanging jig 1 is used for anodic oxidation, an insulative coating film adheres to the product. When the energizing contact part of the hanging jig 1 is rotated in contact with the product 6, the coating film is destroyed by rotating force and a fresh surface comes into contact with the product 6, thereby making it possible to energize the product. If the front end angle of the conical part of the energizing contact part 1 is below 10 deg., the energizing contact part is made finer and the flow of a large current is not possible. If the front end angle is larger than 70 deg., the film destroying power by rotation is weakened and the front end is consumed by repetitive use, by which the diameter is increased to 3mm or over. The preferable front end angle is 30 to 45 deg.. The service life of the hanging jig is thus prolonged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hanging jig used when coating a processed product (hereinafter abbreviated as an aluminum product) made of aluminum or an aluminum alloy. In particular, the present invention relates to a hanging jig that is used when an aluminum product is anodized and then continuously coated by electrophoresis (hereinafter referred to as electrodeposition coating) or dip coating.

[0002]

2. Description of the Related Art Conventionally, in equipment for continuously treating aluminum products from anodic oxidation to electrodeposition coating (or dip coating), the contact point for energizing aluminum products is placed outside the treatment liquid. By providing it and preventing the anodized film and coating from adhering to the contact part, it is repeatedly used as a hanging jig.In such a case, the anodized part of the aluminum product exposed outside the liquid is anodized. The film and the coating film have not been formed. In addition, in the cationic electrodeposition coating, the coating film is repeatedly used by removing the coating film by a burning method using a chemical resistant hanging jig made of SUS or the like. In this case, the energizing contact of the hanging jig has an anode potential in the liquid, so that it elutes with SUS or the like, and it is possible to use a so-called valve metal that causes the oxide film to expand in volume and form an insulating film. Limited to Further, since the coating film has an insulating property, it is necessary to peel off the oxide film and the coating film of the current-carrying contact portion in order to reuse them for anodic oxidation and electrodeposition coating.
Also, even in dip coating, if the coating film remains attached,
Since it also has an insulating property, it was necessary to peel off the coating film of the energizing contact portion in order to use it for the anodizing treatment.

An insulating oxide film is formed even by anodizing treatment, but it is generally used as a pretreatment for the anodizing treatment in the case of a hanging jig having an energizing contact portion made of an aluminum alloy. It is continuously used for film removal in an etching process using an alkaline aqueous solution, for example, an aqueous sodium hydroxide solution. Titanium alloys, zirconium alloys, etc. are widely used as the current contact member material of the anodizing treatment hanging jig. However, since the anodizing voltage of aluminum products is generally as low as 10 to 30V with these metals, Since only a very thin oxide film is formed, the film is destroyed by the edge effect of the contact part, and it has the characteristic that it can be used continuously. With the contact shape, the current value that can be applied is very small, and it was difficult to form an anodized film or electrodeposition film that could be practically used.

[0004]

The problem to be solved by the present invention is that it does not have the above-mentioned drawbacks of the prior art, that is, it can carry a current value sufficient for practical use with a small current-carrying contact portion and is continuous. It is to provide a contact structure for a hanging jig that can be used.

[0005]

[Means for Solving the Problems] When anodizing an aluminum product and then continuously performing electrodeposition coating or dip coating, an anodized film and a coating film are formed on the energizing contact portion of the hanging jig. , Theoretically, there should be neither a coating film nor an anodized film between the energizing contact part of the hanging jig and the contact part of the aluminum product to be processed, which is a very small part. Since the particles are large, it is apparent that it is more difficult to form the contact portion than the anodized film, and the unformed area of the coating film is large. The present invention
This has been done by paying attention to this point of view, and will be specifically described below.

The energizing contact portion of the hanging jig has a tip angle of 1
This is a structure in which an energizing contact portion having a substantially conical portion having a tip diameter of 3 mm or less at 0 to 70 ° is used and the energizing contact portion is rotatably held. Although an anodized film and a coating film are formed on the energizing contact part of the hanging jig with this structure,
Part of the coating film is not formed, so if the anodized film is removed with a commonly used alkaline aqueous solution, etc., only the unformed portion of the coating film will be removed and the coating film will be formed. The other parts are protected. Next, when the aluminum product is hung again and the energizing contact part is rotated, the energizing contact part of the hanging jig with a new surface part where the coating film is destroyed by the rotating force and the anodized film is removed becomes the aluminum product. You will come into contact. At this time, if the rotating portion of the energizing contact portion has a screw structure, the coating film is broken more reliably by the rotation, and at the same time, it has a function of attaching and detaching the aluminum product to the hanging jig. Further, if the energizing contact portion of the hanging jig is rotatably held, the same effect can be obtained in a structure in which the contact portion comes into contact with the aluminum product via a spring or the like. Here, the tip angle of the substantially conical portion is set to 10 to 70 ° because if the angle is less than 10 °, the energizing contact part becomes elongated and it becomes difficult to carry a large current, and if it is greater than 70 °. In addition to weakening the coating film destructive force due to rotation, the tip portion is consumed by repeated use and the tip diameter becomes large, and the tip diameter exceeds 3 mm with a small number of uses, and the coating film destructive force rapidly. Is weakened, and it becomes impossible to energize stably. Therefore, it has been clarified that ideally, if the tip angle is 30 to 45 °, it can be practically used repeatedly.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a state in which the aluminum product is set on a hanging jig, and FIG. 2 shows the energizing contact portion thereof. Further, the power supply section to the hanging jig body is omitted. The energizing contact portion 1 is formed by processing a round bar having a diameter a of 20 mm to a tip angle of about 40 ° and a tip diameter b of about 0.5 mm, and is connected to a threaded titanium bolt 2. Also,
The titanium bolt is rotatably held by the support portion 3. The energizing contact portion 1 may be a titanium alloy, but an aluminum alloy is suitable for energizing a larger large current. The support 3 and the hanging jig body 4 may be used as they are in the case of an aluminum alloy or a titanium alloy, but they may be eluted during the anodizing process in the case of a copper alloy, an iron alloy, SUS or the like. Therefore, resin coating is required for insulation purposes. Considering the baking temperature of electrodeposition coating and the chemical resistance of pretreatment of anodic oxidation, fluororesin coating is preferable. Aluminum product that is the product to be processed 6
Are fixed to the aluminum product holding portion 7 and the energizing contact portion 1 of the present invention.

Various anodizing treatments which are widely carried out in such a state, for example, anodizing treatment in an aqueous solution of sulfuric acid, continuous acrylic electrodeposition coating, which is also widely carried out, and baking are carried out. Processed. The aluminum product was removed by rotating a titanium bolt, the anodized film was removed with an alkaline aqueous solution, and then the aluminum product was hung with a new aluminum product, and the surface treatment was continuously repeated in the same manner. Then, the tip diameter b of the energizing contact portion was 0.5 mm (the state is shown in FIG. 2) at the beginning of use, and was consumed relatively quickly, 2.3 mm, after 10 consecutive uses. Gradually consumed, 50 times in a row, the tip b'is 2.5 mm and the energizing contact part diameter a'is 1
It was 9.9 mm (the state is shown in FIG. 3). During this period, it was possible to stably anodize and electrodeposit aluminum products. The reason for this is that only the contact portion where the coating film is not formed is gradually consumed, and the other portions are protected from being consumed at the time of removing the anodic oxide film by the formation of the coating film. Further, as shown in FIG. 4, the energizing contact portion in the present invention may be used only for energizing, and a product holding portion may be provided separately for fixing the aluminum product.

[0009]

According to the present invention, the anodic oxidation and the coating can be continuously processed, and further, a series of these processes can be repeatedly performed, and the life of the hanging jig can be remarkably extended. did it.

[Brief description of drawings]

FIG. 1 shows an example of a hanging jig structure according to the present invention.

FIG. 2

FIG. 3 shows an energizing contact portion used in the hanging jig of the present invention.

FIG. 4 shows another embodiment of the present invention.

[Explanation of symbols]

 1 ・ ・ ・ ・ ・ ・ energizing contact part 2 ・ ・ ・ ・ ・ ・ titanium bolt 3 ・ ・ ・ ・ ・ ・ supporting part 4 ・ ・ ・ ・ ・ ・ jig body 5 ・ ・ ・・ ・ ・ Resin coating 6,6 '・ ・ ・ Aluminum products 7,8,8' ・ ・ ・ Product holder

Claims (1)

[Claims] 1. A suspending jig structure for continuously coating an anodized product made of aluminum or an aluminum alloy after the product is anodized, wherein the energizing contact portion has a tip angle of 10 to 10.
At 70 °, it has a substantially conical portion with a tip diameter of 3 mm or less,
A suspension jig for energization, wherein the energization contact portion is rotatably held.