JPH05247479A - Lubricating oil and process for low-temperature molding of sheet of aluminum or its alloy - Google Patents

Abstract

PURPOSE:To provide the title oil and the title process by which a sheet of aluminum or its alloy can be molded into a component of a complicated shape even when its processing is hard. CONSTITUTION:The title oil consists mainly of paraffins, has a viscosity of 50cSt or below at 40 deg.C and is suited for use in low-temperature molding. When a sheet of aluminum or its alloy is pressed at low a temperature, it is coated with the above lubricating oil, cooled and molded at a sheet temperature in the range of -50 to -150 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low temperature forming method for Al and Al alloy sheets, and particularly to low temperature effective for complex shapes difficult to form in automobile parts, electric equipment parts, aircraft parts, articles and the like. The present invention relates to a press molding method.

[0002]

2. Description of the Related Art Conventionally, when Al and Al alloy plates are applied in the molding of automobile parts, electric equipment parts, aircraft parts, articles, etc., there is a limit to the processing in ordinary press forming. However, when the processing is strict or when molding is performed into a component having a complicated shape, the pressing process has to be performed by dividing it into a plurality of times, which inevitably results in an increase in cost due to an increase in the number of steps.

Under such circumstances, from the viewpoint of environmental problems such as global warming and ozone layer destruction, the weight reduction of automobiles has been seriously studied in order to suppress the increase of carbon dioxide gas in the atmosphere. ing. There are various ways to reduce the weight, but it is considered to reduce the weight by replacing the material, that is, by frequently using Al or Al alloy sheet instead of the steel sheet that has been mainly used in the past, and the amount of use increases. It's starting. However, since the formability of Al or Al alloy plate is inferior to that of steel plate, there is a strong need for improvement in terms of material and press forming method.

In response to these demands, in terms of materials, as proposed in JP-A-63-89649, an attempt has been made to improve the formability of the material by optimizing the component composition of the Al material and the manufacturing process. It has been done.

However, in recent years, there has been an increasing demand for more rigorous processing and molding into a complicated shape, and it is not sufficient to improve only the material side.

On the other hand, in terms of processing, the Institute of Invention and Innovation open technical report 89
Although the molding method at extremely low temperature is mentioned in No. -15623, only the influence of the mechanical properties of the material and the molding temperature is disclosed, and from the viewpoint of improving the moldability in actual molding, the actual situation is It doesn't fit in.

The present invention has been made in order to meet such a demand, and is a technique capable of forming Al and Al alloy plates, particularly in the case where the processing is severe or when a component having a complicated shape is processed with good formability. It is intended to be provided.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies on a method of forming Al and Al alloy sheets in order to achieve the above-mentioned object, and as a result, by controlling the lubricating condition and the forming temperature, I found that I can solve.

That is, the present invention is based on a lubricating oil for forming Al and Al alloy sheets, which is mainly composed of paraffin and has a viscosity at 40 ° C. of 50 cSt or less.

According to another aspect of the present invention, Al and Al alloy sheets are coated with a lubricating oil containing paraffin as a main component and having a viscosity at 40 ° C. of 50 cSt or less, and then the material is cooled,
The gist is a press forming method for Al and Al alloy plates, which is characterized in that the material temperature is formed in the range of -50 to -150 ° C.

The present invention will be described in more detail below.

[0012]

[Action]

First, the reasons for limiting the lubricating oil of the present invention will be described.

Lubricating oil generally has a higher viscosity at lower temperatures, but when the lubricating oil containing paraffin is cooled, the paraffin solidifies into a wax and forms a lubricating film, which enhances the lubricating effect. Therefore, the main component is paraffin,
Use paraffin-rich lubricating oil.

The higher the viscosity of the lubricating oil, the better the lubricity, but when the viscosity at 40 ° C. exceeds 50 cSt,
Although it has good moldability, it becomes a solid wax at room temperature,
Degreasing defects are likely to occur in the degreasing process, which causes joining defects in the bonding process such as adhesion and welding in the subsequent process. Therefore, the lubricating oil containing paraffin as the main component is limited to those having a viscosity at 40 ° C. of 50 cSt or less.

Note that this lubricating oil contains only paraffin (1
In addition to the case of (00% by weight), it is preferable that paraffins contain 50% by weight or more. This is because the main component, paraffin, is advantageous in forming a uniform film when it becomes waxy at low temperature.

Components other than paraffin are components that solidify (freeze) in a low temperature state and cause destruction of the lubricating film.
Except for (water and the like), for example, an extreme pressure agent may be added if necessary.

Next, the press molding method of the present invention will be described.

Al and Al which are the objects of the molding process according to the present invention
The alloy does not become brittle at low temperatures and, conversely, the strength and the elongation are improved, as shown in the above-mentioned JP-A-89-15623. Of course, the component system and composition of the Al alloy are not limited.

As a method for cooling the material to a low temperature, an appropriate method can be applied, but from the viewpoint of versatility, cost, etc., immersion with liquid nitrogen or direct spraying into a mold is preferable.

The lower the material temperature during molding, the better, but -5
When the temperature is higher than 0 ° C, the effect of improving the moldability is small. On the other hand, when the temperature is lower than −150 ° C., the moldability is deteriorated due to the deterioration of the lubricating oil, and the cost is increased. Therefore, the material temperature during molding is -50 ° C to -1.
The range is 50 ° C.

Next, examples of the present invention will be described.

[0023]

Example 1 An O material of JIS5182 alloy having a plate thickness of 1 mm was used as a molding material. A molding test (BHF: 4.0 Tonf, average speed: 15 m / min) was performed using a crank press using the ball head mold shown in FIG. At that time, as a lubricant for the material

[Table 1] Various oils shown in 1 were applied, immersed in liquid nitrogen for 2 minutes and cooled, and then subjected to the test. Some of them were subjected to the test immediately after applying the lubricating oil.

The moldability was evaluated by changing the position of the bottom dead center of the press to gradually increase the height of the molded product and determining the molding limit height at which the molded product cracks. The degreasing property was evaluated by degreasing the material coated with the lubricating oil with a commercially available degreasing agent (the degreasing conditions are shown in Table 1), and then determining the residual oil condition by the water leakage area ratio. The results are as shown in Table 1, and in the examples of the present invention, the improvement of the molding limit height was recognized and the degreasing property was good as compared with the comparative examples. In particular, the moldability at low temperature (-148 ° C) was remarkable.

[0025]

[Embodiment 2] O material of JIS5182 alloy and a steel plate are used as materials, and the viscosity of the lubricating oil at 40 ° C is 10c.
Paraffinic mineral oil of St (polyethylene sheet was used for some materials) was applied, and the materials were pressed at various molding temperatures. The result is shown in FIG. From the figure, it can be seen that the use of the lubricating oil of the present invention improves the forming limit height of the Al alloy particularly at a low temperature of -50 ° C or lower. It should be noted that the forming height is most improved when the material temperature is -196 ° C, but it takes 1 to cool the material to this temperature.
It took 20 minutes per piece.

[0026]

As described in detail above, according to the present invention,
Al and Al for various molded products with complicated shapes that are difficult to process
The use of alloy plates is possible, and the effect that can greatly contribute to weight reduction of products is remarkable.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a mold used in a molding test.

FIG. 2 is a diagram showing the influence of molding temperature and cooling conditions on the overhang height in Example 2.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshio Okamoto 15 Kinugaoka, Moka City, Tochigi Prefecture Kobe Steel Works Moka Works

Claims (3)

[Claims] 1. Paraffin as a main component and 40 ° C.
A has a viscosity of 50 cSt or less
L and Al alloy plate forming lubricating oil. 2. The lubricating oil according to claim 1, which is for low temperature molding. 3. An Al and Al alloy plate is coated with a lubricating oil containing paraffin as a main component and having a viscosity at 40 ° C. of 50 cSt or less, and then the material is cooled to a material temperature of −50 to −.
A method for press-molding Al and Al alloy plates, which comprises molding in the range of 150 ° C.