JP2002194590A - Surface treatment method for aluminum extrusion having hole with small diameter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface treatment method concerning on frame setting and removing, for aluminum extrusions having holes with small diameter, which prevents intrusion of a corrosive liquid into the holes with small diameter, and dispenses a washing/drying process in a post-process. SOLUTION: The surface treatment method for the aluminum extrusions having holes with small diameter is characterized by sealing both ends of the holes of small diameter, with an elastic cap, before the surface treatment. The cap comprises; an insert part of which the outer diameter is a little larger than the holes with small diameter of the extrusions; a needle insert hole of which the length is 15-30 mm, the diameter is 1-4 mm, and the top is sealed; and a flange on the basal part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface treatment, such as anodizing, of an aluminum mold having a penetrated small-diameter hole which does not require surface treatment, in addition to a surface requiring surface treatment such as a rodless cylinder. The present invention relates to a method for efficiently forming a small diameter hole and removing the frame.

[0002]

2. Description of the Related Art Aluminum molds are usually provided with corrosion resistance by performing surface treatment or the like by anodic oxidation. For example, such as a rodless cylinder having a slit-shaped opening communicating with the outside in a thin-walled hollow portion. In an eccentric semi-hollow extruded material or the like, an extrusion adjusting hole or a small-diameter hole for a passage of a fluid such as air or lubricating oil is provided in order to equalize the metal flow speed around the hollow portion. I have. When the material to be surface-treated has a small-diameter hole in addition to the inner surface to be surface-treated, when the anodic oxidation treatment is performed by a normal framing method, the surface treatment liquid does not require the treatment. There is a danger that it will penetrate into the holes and cause corrosion to proceed with acids, alkalis, salts and the like as the anodization proceeds.

[0003] In particular, in a small-diameter hole, once an anodizing treatment liquid or the like once enters, it is difficult to completely and easily remove it by washing with water or the like. Further, even if the oxidizing solution can be completely removed by washing with water, subsequent drying is required, and since the holes are small in diameter, it becomes difficult to dry the inside.

If washing with water cannot be performed completely, corrosive acids, alkalis or salts such as a corrosive anodizing solution or a cleaning solution remain, and there is a risk that the small-diameter hole is blocked by corrosion. In particular, when manufacturing a product that uses this small-diameter hole as a passage for a fluid such as lubricating oil or air, it is necessary not only to remove foreign matter in the small-diameter hole, but also to reduce the quality and in extreme cases. May cause serious danger such as stoppage of the entire apparatus.

[0005]

An object of the present invention is to provide a method for framing or removing a frame of an aluminum mold having a small-diameter hole, which reliably prevents invasion of corrosive liquid into the small-diameter hole by a simple operation. In addition, an object of the present invention is to develop a surface treatment method for an aluminum mold material which does not require a subsequent washing and drying step, an elastic cap used therefor, and a jig for inserting the same.

[0006]

According to the present invention, there is provided [1] a method for performing a surface treatment on an aluminum mold material having a small-diameter hole, wherein the surface treatment is performed after both ends of the small-diameter hole are sealed with elastic caps. [2] The surface treatment method for an aluminum mold material according to the above [1], wherein the surface treatment is a treatment method for forming an oxide film by anodic oxidation; The surface treatment method for an aluminum mold according to the above [1] or [2], wherein an elastic cap having a needle insertion hole having a flange at a root portion and a sealed end is used, [4] an elastic cap [1] to [3], wherein the insertion portion has an outer diameter slightly larger than the small-diameter hole of the mold material, a length of 15 to 30 mm, and a needle insertion hole diameter of 1 to 4 mm.
Surface treatment method of an aluminum mold according to any one of,
And [5] The aluminum according to any one of [1] to [4], wherein the needle of the jig for inserting a cap is inserted into the hollow portion of the elastic cap, the elastic cap is inserted into the small-diameter hole, and the small-diameter hole is sealed. The above object was achieved by developing a surface treatment method for a mold material.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The aluminum mold material to be used in the present invention is usually a mold material formed by extrusion, and requires a surface treatment as a whole, but a small diameter which does not require a surface treatment on the inner surface. Applicable to molds having holes. The small-diameter hole is a through hole having a cross-sectional area of about 15 mm square, such as a circle, an ellipse, a triangle, a square, a polygon, a fan, and a star. If there is, it can be applied to most of them. Usually, it is a circular through hole of about 3 to 15 mmφ.

As the surface treatment method, surface treatment such as chromic acid treatment, alumite treatment, plating treatment and the like generally performed on aluminum or aluminum-based alloys can be mentioned. In particular, an oxide film is formed on the surface by anodic oxidation. Is effective in surface treatment for forming In the case of these surface treatments, an aqueous solution of an acid, alkali or salt which is highly corrosive to the aluminum material is often used. After the surface treatment, these corrosive liquids are immediately removed by washing with water or the like. It is common to dry the product or send it to the next step for further processing.

When a corrosive surface treatment liquid enters the small-diameter hole, the inner surface of the small-diameter hole is naturally corroded.
Generally speaking, once the surface treatment liquid has entered, it cannot be removed by superficial showering or simple cleaning such as dipping in the cleaning liquid, and the cleaning liquid is forcibly passed through each small-diameter hole to be removed. Must be removed.

Further, in order to dry the inner surface of the small-diameter hole, it is impossible to dry the inside of the small-diameter hole by a simple drying method such as drying in a dryer. It is necessary to dry the inner surface. These operations lead to significant cost increases. These washing and drying processes become more complicated as the number of small-diameter holes provided in the mold material increases. Therefore, in order to prevent these problems from occurring, it is necessary to prevent the above corrosive liquid from entering the small-diameter hole.

In the present invention, elastic caps are inserted into both ends of all of the small-diameter holes that do not require surface treatment of the inner surface, and the small-diameter holes are sealed to prevent the invasion of corrosive liquid into the inside, thereby preventing corrosion. And succeeded in eliminating the need for a drying step. Although this method is extremely simple and has an excellent effect, it has not been performed at all and can be said to be an egg-like method of Columbus.

The material of the elastic cap used here has sufficient corrosion resistance to a corrosive surface treatment solution under surface treatment conditions, and has elasticity required for the cap material.
Use an elastic body having rigidity. As the elastic body, for example, natural rubber; synthetic rubber such as fluorine rubber, neoprene rubber, ethylene-propylene rubber, acrylic rubber, urethane rubber; or soft synthetic resin such as polyethylene, polyvinyl chloride, polyester, polyamide, etc. Or those foams, which may be appropriately selected and used according to the surface treatment conditions.

[0013] The shape of the elastic cap is such that the liquid cap can be sufficiently sealed when inserted into the small-diameter hole (there is a slight taper so that it can be easily inserted into the small-diameter hole and does not easily come out when inserted). Thickness is required.
If the cross section of the small-diameter hole is circular, it is necessary to make it slightly larger than the cross section. The shape may be any shape as long as the elastic cap can be inserted into the small-diameter hole to sufficiently seal the liquid, and can be easily removed after the treatment. For example, as shown in FIG. 1 , a flange 2 is provided at the root so that the entire elastic cap 1 does not enter the small-diameter hole to the root, and a hollow hole 3 (the needle of the jig for cap insertion) is sealed at the tip. A hollow column having a slight taper having a hollow hole for insertion) is preferable. The flange portion has a shape that does not cover the surface to be surface-treated at all.

The length of the hollow column is not particularly limited. However, considering the ease of handling such as liquid sealing and removal, the length is 15 mm.
About 30 mm, hollow hole 3 is 1-4 mmφ, preferably 2 mm
３3 mmφ. It is easy to fit the needle of the jig for inserting the cap into the hollow hole 3 and insert the cap into the small-diameter hole. Further, if this hollow hole is provided, the cap will be more elastic. There is an advantage that it is easy to insert the cap and remove the cap after the surface treatment.

The jig for inserting a cap may have a large number of needles or a single needle in accordance with the arrangement of the small diameter holes. It is advantageous to ensure the insertion position of the cap. It is necessary to round the tip of the needle so as not to break through the elastic cap. It is also advantageous here that the needle is coated with lubricating oil or the like so that it can be easily removed from the cap after insertion.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An aluminum mold having a shape as shown in FIG.
Form member 10 consisting of 1N30 of mm square and length of 200 mm
And the hollow portion 12 having an eccentric 20 mmφ slit
And two small diameter holes 14 of 6 mmφ and two 3 m
m having a small diameter hole 16. An elastic cap made of natural rubber as shown in FIG. 1 is inserted into each of the small-diameter holes 14 and 16 using a jig for sealing the cap, and both ends of the small-diameter hole are sealed. Was formed. When the elastic cap was removed after washing with water and drying, no treatment liquid had penetrated into any of the small diameter holes. When anodic oxidation was performed without using an elastic cap, foreign matter was generated in all the small-diameter holes after the treatment due to corrosion of the inner surface, and removal treatment, cleaning treatment, and drying treatment were required.

[0017]

According to the method of surface treating an aluminum mold according to the present invention, in the method of surface treating an aluminum mold having a small diameter hole, the surface treatment is performed after both ends of the small diameter hole are sealed with elastic caps. With a simple operation, it is possible to reliably prevent the corrosive processing liquid in the small diameter hole from entering the small diameter hole during the surface treatment, so that the cleaning step and the drying step of removing the processing liquid after the surface treatment are performed. Even if it is unnecessary, it is possible to prevent blockage of the small-diameter hole due to corrosion and progress of corrosion during storage, which can greatly contribute to prevention of failure and cost reduction.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of an elastic cap according to the present invention.

FIG. 2 shows an example of an aluminum profile having a small diameter hole used in the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Elastic cap 2 Flange 3 Hollow hole 10 Mold material 12 Hollow part having a slit 14 6 mm small diameter hole 16 3 mm small diameter hole

Claims (5)

[Claims] 1. A method for surface-treating an aluminum mold having a small-diameter hole, wherein the surface treatment is performed after both ends of the small-diameter hole are sealed with elastic caps. 2. The method according to claim 1, wherein the surface treatment is a method of forming an oxide film by anodic oxidation. 3. The method according to claim 1, wherein the elastic cap has a flange at a root portion and an elastic cap having a needle insertion hole sealed at a tip end. . 4. The elastic member cap according to claim 1, wherein the insertion portion of the elastic cap has an outer diameter slightly larger than the small-diameter hole of the mold material, a length of 15 to 30 mm, and a needle insertion hole diameter of 1 to 4 mm. A surface treatment method for the aluminum mold according to the above. 5. The aluminum according to claim 1, wherein a needle of a jig for inserting a cap is inserted into a hollow portion of the elastic cap, an elastic cap is inserted into a small-diameter hole, and the small-diameter hole is sealed. Surface treatment method for mold material.