TW201718899A - Chassis for small electronic device and method for forming same, and rolled aluminum alloy laminated sheet material for chassis for small electronic device - Google Patents

Abstract

To provide a chassis for a small electronic device that can be formed efficiently by drawing work with low cost, is hard to cause forming failure, and causes no damage on the surface thereof on forming to provide an excellent appearance. The rolled aluminum alloy laminated sheet material is for forming a chassis for a small electronic device by drawing work, and contains a rolled aluminum alloy sheet material having a 0.2% proof stress of 200 MPa or more, and a covering material laminated at least one surface of both surfaces of the rolled aluminum alloy sheet material, and the covering material contains any one of a synthetic resin film, and a laminated material containing a metal foil having synthetic resin films laminated on both surfaces thereof. The rolled aluminum alloy sheet material may have a fibrous crystalline structure extending in a direction perpendicular to a thickness direction thereof.

Description

Small electronic machine casing and forming method thereof, and aluminum alloy rolled laminated board for small electronic machine casing

The present invention relates to a casing for a tablet computer, a communication terminal device, a notebook computer, a mobile phone, a portable electronic device, a digital camera, and the like, and a method for forming the same, and an aluminum alloy calender used as a molding material for the same casing Laminated sheets.

Conventionally, the outer casing of a small-sized electronic device is known to be formed by cutting (total shaving) a thick-plate-shaped aluminum alloy extruded material (for example, refer to Patent Document 1 below).

Since the above-mentioned outer casing can obtain excellent appearance, precision and strength, it can be suitably used as a small electronic machine casing.

Further, in general, a kneading process is widely used from a metal plate material such as an aluminum alloy plate to form a product having a predetermined shape.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Laid-Open Patent Publication No. 2012-246555 (JP2012-246555A)

However, in the case of a small electronic machine casing formed by cutting, it takes a long time to cut the material, so the manufacturing efficiency is low, and in addition, a large amount of chips are generated along with the processing, and this is recovered. Processing must consume a lot of energy, and the result is a cost increase.

On the other hand, in the case of the drawing process, since the molding is performed in a short time, the production efficiency is excellent, and since the flying chips are not generated accompanying the processing, the production can be performed at low cost. However, the form of the outer casing of the small electronic device generally includes a bottom wall which is slightly square when viewed in plan, and a side wall which is stood by the periphery of the bottom wall. When the outer casing of such a shape is formed by the drawing process, cracks are formed in the corner portions of the side wall, and the molding failure is extremely large.

Further, in the case of the skewing process, since the surface of the metal sheet is in sliding contact with the mold, there is a possibility that the surface of the molded article is scratched and the appearance of the product is impaired.

SUMMARY OF THE INVENTION An object of the present invention is to provide a small electronic machine casing which is not only capable of being formed by high-efficiency and low-cost molding by butting processing, but also which is difficult to cause molding defects, and which does not damage the surface by molding. Has an excellent appearance.

The present invention has been made in view of the following aspects in order to achieve the above object.

1) An aluminum alloy rolled laminated sheet material for a small electronic machine casing, which is formed by an aluminum alloy rolled laminated sheet material which is formed into a small electronic machine casing by a drawing process, and is characterized in that it is composed of an aluminum alloy rolled sheet material and a covering material, The aluminum alloy rolled sheet has a 0.2% proof resistance of 200 MPa or more; the coated material is laminated on at least one of the two faces of the aluminum alloy rolled sheet; and the coated material is synthesized from a synthetic resin film and a two-layer layer of the metal foil. At least one of the laminates of the resin film is formed.

2) The aluminum alloy calendered laminate sheet for a small electronic machine casing according to the above 1), wherein the aluminum alloy rolled sheet has a fibrous crystal structure extending from a direction orthogonal to the thickness direction.

3) An aluminum alloy calendered laminate sheet for a small electronic machine casing according to the above 1) or 2), wherein the aluminum alloy rolled sheet is made of an Al-Mn-Mg alloy, an Al-Si-Mg alloy, and an Al- An aluminum alloy of any one of Zn-Mg alloys; and an Al-Mn-Mg alloy is composed of Mn: 0.2 to 0.7% by mass, Mg: 2.0 to 5.0% by mass, The Al-Si-Mg alloy is composed of Si: 0.2 to 0.8% by mass, Mg: 0.4 to 1.2% by mass, residual Al and unavoidable impurities; The Al-Zn-Mg-based alloy is formed of Zn: 4.0 to 6.5% by mass, Mg: 0.5 to 3.0% by mass, residual Al, and unavoidable impurities.

4) The aluminum alloy rolled laminated board for a small electronic machine casing according to any one of the above 1), wherein the thickness of the covering material is 0.05 to 1.5 times the thickness of the aluminum alloy rolled sheet.

5) Aluminum alloy for a small electronic machine casing according to any one of the above 1) to 4) The gold rolled laminate sheet, wherein the thickness of the aluminum alloy rolled sheet is 0.5 to 3.5 mm.

(6) The aluminum alloy rolled laminated board for a small electronic machine casing according to any one of the above 1) to 5), wherein the surface of the outer surface of the small electronic machine casing is formed on both sides of the aluminum alloy rolled sheet, and the thickness of the laminated layer is 50~ A 100 μm polyester resin film or a polyamide resin film is used as a coating material.

(7) The aluminum alloy rolled laminated sheet material for a small electronic machine casing according to any one of the above 1), wherein the surface of the inner surface of the small electronic machine casing is formed on both sides of the aluminum alloy rolled plate, and the thickness of the laminated layer is thick. A coating material of a polyethylene resin film, a polypropylene resin film or a polyamide resin film of 10 to 100 μm is used.

8) A small electronic device casing with a covering material, characterized in that the aluminum alloy rolled laminated sheet material for a small electronic machine casing according to any one of the above 1) to 7) is subjected to a drawing process, and at least one of the inner and outer surfaces The surface is covered with a synthetic resin film or a laminate to form a covering material.

9) A small electronic device casing characterized in that, after the aluminum alloy rolled laminated sheet material for a small electronic machine casing according to any one of the above 1) to 7) is subjected to a drawing process, the surface of at least one of the inner and outer faces is removed. The covering material.

10) The small electronic device casing according to the above 9), wherein the bottom wall has a side wall standing from the periphery of the bottom wall, and the height of the side wall is 0.5 to 25 mm, and the side wall angle is 90 with respect to the bottom wall. ~150°.

11) A method of forming a small electronic machine casing, characterized in that the aluminum alloy rolled laminated sheet material for a small electronic machine casing according to any one of the above items 1) to 7) is subjected to a drawing process.

According to the above-mentioned 1), the aluminum alloy rolled laminated sheet material for the small electronic device casing is used as the aluminum alloy rolled sheet material of the outer casing, and the 0.2% proof force is 200 MPa or more, so that the desired outer shell strength can be ensured.

Further, according to the aluminum alloy rolled laminated sheet material of the above 1), a synthetic resin film or a covering material is laminated on at least one of both surfaces of the aluminum alloy rolled sheet, and the covering material is on both sides of the metal foil. The laminated body of the laminated synthetic resin film has a small frictional resistance, so that wrinkles are not formed on the side wall of the formed outer casing due to the twisting process, and cracks are not formed in the corner portions of the side wall, thereby suppressing the forming. In addition to the occurrence of defects, the surface damage of the outer casing caused by contact with the mold can be prevented without damaging the appearance of the outer casing.

According to the aluminum alloy rolled laminated sheet material for the small electronic device casing of the above 2), since the aluminum alloy rolled sheet has a fibrous crystal structure extending in a direction orthogonal to the thick direction, the strength of the sheet is increased for bending. It is difficult to cause formation defects such as wrinkles or cracks.

The aluminum alloy rolled laminated sheet material for the small electronic machine casing according to the above 3), the aluminum alloy rolled sheet material is composed of the Al-Mn-Mg alloy, the Al-Si-Mg alloy, and the Al-Zn-Mg having the above respective compositions. The aluminum alloy of any of the alloys can be formed by a drawing process, and an outer casing having excellent precision and strength and excellent appearance can be obtained.

According to the above 4), the aluminum alloy rolled laminated plate material for the small electronic machine casing is 0.05 to 1.5 times the thickness of the aluminum alloy rolled plate because the thickness of the coated material is 0.05 to 1.5 times. Avoid the following questions.

That is, when the thickness of the covering material is less than 0.05 times the thickness of the aluminum alloy rolled sheet, the covering material is broken and the position where the molded article comes into contact with the mold is damaged. On the other hand, when the thickness of the covering material exceeds 1.5 times the thickness of the aluminum alloy rolled sheet, the above effects cannot be obtained, and only the cost is increased.

According to the above-mentioned 5), the aluminum alloy rolled laminated plate material for the small electronic device casing has the following problems because the thickness of the aluminum alloy rolled plate is 0.5 to 3.5 mm.

That is, when the thickness of the aluminum alloy rolled sheet material is less than 0.5 mm, the strength of the final product may be insufficient. On the other hand, when the thickness of the aluminum alloy rolled sheet exceeds 3.5 mm, the radius of curvature (R) of the bent portion or the corner portion is excessively large.

According to the above 6), the aluminum alloy rolled laminated sheet material for the small electronic machine casing can achieve the following effects. That is, when the aluminum alloy rolled laminated sheet material is subjected to the drawing process and formed into a small electronic machine casing, the surface of the outer surface of the small electronic machine casing is formed on both sides of the plate material, and although the surface is partially rubbed with the mold, if the thickness is 50~ When a 100 μm polyester resin film or a polyamide resin film is used as a coating material coated with the same surface, the film is not broken by friction of the mold, and the surface damage of the molded article can be surely avoided, and the thickness of the film can be suppressed from being excessively large. Further, the increase in cost can further avoid the excessive rigidity of the film, resulting in protrusion or peeling of the bent portion of the outer casing.

According to the above 7), the aluminum alloy rolled laminated sheet material for the small electronic machine casing can achieve the following effects. That is, when the aluminum alloy rolled laminated sheet material is subjected to the drawing process and formed into a small electronic machine casing, the surface of the inner surface of the small electronic machine casing is formed on both sides of the plate material, and although it does not rub against the mold, in order to make it in the concave direction Part of the bending forming, use thick A polyethylene resin film, a polypropylene resin film or a polyamide resin film having a degree of 10 to 100 μm is used as a coating material covering the same surface, and it is possible to avoid partial protrusion or peeling of the outer shape of the outer casing due to excessive rigidity of the film. It is possible to avoid a situation in which the radius of curvature (R) of the portion formed by bending of the outer casing is increased and a sharp shape cannot be obtained.

According to the above-mentioned 8), the small-sized electronic machine casing with the covering material can perform the forming of the aluminum alloy rolled sheet well by the drawing process, and the surface is not damaged during the forming, thereby obtaining a beautiful appearance with high precision and strength. The outer casing.

Further, according to the above-mentioned 8), the small electronic device casing with the covering material is covered by the covering material, so that surface damage during storage or transportation can be prevented.

According to the small electronic device casing of the above 9), the aluminum alloy rolled sheet can be favorably formed by the drawing process, and the surface is not damaged during molding, further storage, or transportation, so that high precision can be obtained. And a shell that is strong and has a beautiful appearance.

According to the small electronic device casing of the above 10), since the height of the side wall is 0.5 to 25 mm and the angle of the side wall is 150 with respect to the bottom wall, the following problems can be avoided.

That is, when the height of the side wall is less than 0.5 mm, the cutting portion of the latter step is more. On the other hand, when the height of the side wall exceeds 25 mm, the thickness of the small electronic machine may increase.

Further, when the angle of the side wall is less than 90 with respect to the bottom wall, that is, when the side wall is inclined inward, the corner portion may wrinkle and the processing is difficult. On the other hand, when the angle of the side wall exceeds 150° with respect to the bottom wall, the depth of the outer casing becomes shallow, and the storage volume of the components accommodating the small electronic device is reduced.

According to the above 11) small electronic machine housing forming method, with high precision A small electronic machine casing that has a high density and strength and a beautiful appearance can be formed efficiently and at low cost by the drawing process.

(1)‧‧‧Aluminum rolled laminated sheets

(2)‧‧‧Aluminum alloy rolled sheet

(3) (4) ‧‧‧ Covering materials

(30) (40) ‧‧‧Synthetic resin film

(31) (41)‧‧‧Metal foil

(32)(33)(42)(43)‧‧‧Synthetic resin film

(5) ‧ ‧ fixed female

(6) ‧‧‧ movable male

(20)‧‧‧Small electronic machine housing

(21) ‧‧‧ bottom wall

(22)‧‧‧ Sidewall

(22a) ‧‧‧ (side wall) corner

Fig. 1 is a partially enlarged cross-sectional view showing a layer structure of an aluminum alloy rolled laminated sheet material for a small electronic device casing of the present invention.

Fig. 2 is a vertical sectional view showing, in order, a step of forming a small electronic machine casing by twisting a same plate.

Fig. 3 is a perspective view showing the outer casing of the small electronic machine of the present invention.

Fig. 4 is a perspective view showing a cross-sectional direction when a rolled aluminum alloy rolled sheet is bent and a fibrous crystal structure of a cross section is observed.

Fig. 5 is a photomicrograph of a section of the bent material (inner labyrinth: 0 mm) of the aluminum alloy rolled sheet (section direction with respect to the rolling direction: 90°).

Fig. 6 is a photomicrograph of a section of the bent material (inner labyrinth: 0.4 mm) of the aluminum alloy rolled sheet (section direction with respect to the rolling direction: 90°).

Fig. 7 is a photomicrograph of a section of the bent material (inner labyrinth: 0 mm) of the aluminum alloy rolled sheet (section direction with respect to the rolling direction: 0°).

Fig. 8 is a photomicrograph of a section of a bent material (inner labyrinth: 0.4 mm) of an aluminum alloy rolled sheet (section direction with respect to the rolling direction: 0°).

Hereinafter, an embodiment of the present invention will be described with reference to Figs.

Fig. 1 is a view showing a layer structure of an aluminum alloy rolled laminated sheet (1) for a small electronic machine casing of the present invention.

As shown in the figure, the aluminum alloy rolled laminated sheet (1) for the small electronic machine casing is made of aluminum alloy rolled sheet (2) and aluminum alloy rolled sheet (2) on both sides of the laminated layer (3) (4). Composition.

The aluminum alloy rolled sheet (2) is 0.2% or more, preferably 250 MPa or more, and more preferably 300 MPa or more. Thereby, the strength of the desired outer casing can be obtained. Further, in the aluminum alloy rolled sheet (2), those having an elongation at break of 5% or more and 20% or less are suitably used. Thereby, the formability of the stretching process can be improved. Here, "0.2% proof stress" and "elongation at break" were obtained by using a test piece No. 5 prescribed in JIS Z 2241-2011 and performing a tensile test in parallel in the rolling direction.

Further, the aluminum alloy rolled sheet (2) has a fibrous crystal structure extending in a direction orthogonal to the thickness direction.

The fibrous crystal structure is formed by calendering the homogenized aluminum alloy ingot after heat treatment, heat treatment under predetermined conditions, and then performing cold rolling. The heat treatment is carried out by holding at 200 to 400 ° C for 1 hour or more. By the aforementioned heat treatment, Mg ₂ Si can be finely and uniformly precipitated, and the processing strain existing in the rolled material can be reduced. Then, it is work hardened by cold working, and a high-strength aluminum alloy rolled sheet which does not impair the range of subsequent moldability can be obtained.

The conditions for the homogenization treatment of the aluminum alloy ingot are not particularly limited, and it is preferably carried out at 500 ° C or more and 2 hours or more according to a usual method.

The inter-heat rolling is obtained by the same effect as quenching by performing a temperature reduction of the temperature at a temperature determined in an arbitrary path step. Therefore, the material temperature before the path must be at a temperature of 350 to 440 ° C which can maintain Mg and Si in a solid solution state. In order to make the path completion temperature into the temperature range of 200 to 400 ° C described above, it is also possible to perform forced cooling such as high-pressure shower water cooling immediately after the hot-rolling is completed. Further, in order to obtain the quenching effect, the cooling rate between the paths is 50 ° C / min or more, the path completion temperature is 250 to 340 ° C, and the path rolling speed is 50 m / min or more, and the thickness is 10 mm or less.

Calender rolling, in order to obtain a predetermined strength by work hardening, the system reduction ratio is 30% or more. Preferably, the reduction ratio is 50% or more.

Further, if necessary, the cold-rolled alloy sheet may be finally blunt at a temperature of 130 to 150 °C. By heat-treating at a low temperature, it is aged hardened to further increase the strength, and the elongation can be improved. In addition, there is also the effect of making the physical properties of the machine stable.

The aluminum alloy rolled sheet (2) can be suitably formed using any of the following aluminum alloys.

i) Al-Mn-Mg-based alloy containing Mn: 0.2 to 0.7% by mass, Mg: 2.0 to 5.0% by mass, and formed by residual Al and unavoidable impurities

Ii) Al-Si-Mg alloy containing Si: 0.2 to 0.8% by mass, Mg: 0.4 to 1.2% by mass, and formed by residual Al and unavoidable impurities

Iii) Al-Zn-Mg alloy containing Zn: 4.0 to 6.5 mass%, Mg: 0.5 to 3.0 mass%, and formed by residual Al and unavoidable impurities

The alloy of the above i) may, for example, contain Si: 0.4% by mass or less, Mn: 0.4 to 0.6% by mass, Mg: 4.0 to 4.9% by mass, and Fe: 0.4 mass. % or less, Cr: 0.05 to 0.25 mass%, and Zn: 0.25 mass% The aluminum alloy is made of the residue Al and the unavoidable impurities.

The alloy of the above ii) may, for example, contain Si: 0.2 to 0.6% by mass, Mg: 0.45 to 0.9% by mass, Fe: 0.35% by mass or less, and Cr: 0.1% by mass. % or less, Zn: 0.1% by mass or less, and an aluminum alloy formed of the residue Al and the unavoidable impurities.

The alloy of the above iii) may, for example, contain Si: 0.4% by mass or less, Mg: 2.1 to 2.9% by mass, Fe: 0.5% by mass or less, and Cu: 1.2 to 2.0. Mass%, Mn: 0.3% by mass or less, Cr: 0.18 to 0.28% by mass, Zn: 5.1 to 6.1% by mass, and an aluminum alloy formed of the residue Al and the unavoidable impurities.

Among these, Si: 0.2 to 0.6% by mass, Mg: 0.45 to 0.9% by mass, Fe: 0.35% by mass or less, and Cr: 0.1% by mass or less. Zn: 0.1% by mass or less, and an aluminum alloy rolled sheet (2) made of an aluminum alloy having a residual portion Al and an unavoidable impurity, can be suitably used as a molding material for a small electronic machine casing.

Further, the thickness of the aluminum alloy rolled sheet (2) to be used may be appropriately set depending on the molding conditions or the size of the outer shell of the molded article, and is preferably 0.5 to 3.5 mm, more preferably 0.8 to 1. 2mm.

The covering material (3) (4) is used to improve the formability of the aluminum alloy rolled sheet (2) during the drawing process, and to reduce the use of the lubricant during forming and to prevent surface damage of the sheet (2) during forming. Further, after the outer casing is formed, for example, the surface of the outer casing is protected during storage or transportation.

The covering material (3) (4) has a laminate formed by using two-layer synthetic resin films (32) (33) (42) (43) of the metal foil (31) (41) as shown in Fig. 1 (a). (3) (4), as shown in Figure 1(b) As shown, the case of the synthetic resin film (30) (40) is used.

The metal foil (31) (41) constituting the laminated body (3) (4) of the covering material in the aluminum alloy rolled laminated board (1) for a small electronic device casing according to the first aspect shown in Fig. 1(a), Listed as aluminum foil, stainless steel foil, copper foil. Further, the synthetic resin film (32) (33) (42) (43) of the laminate (3) (4) may, for example, be an unstretched polypropylene resin film (CPP) or polyethylene terephthalate. Resin film (PET), nylon resin film (Ny), polyimide film (PI), polyethylene resin film (PE), etc., or such stretch film. Lamination of the metal foil (31) (41) and the synthetic resin film (32) (33) (42) (43), for example, by polyester urethane resin (PAUR), acrylic resin, acid denaturation polymerization An olefin resin (APO) or the like is formed as an adhesive layer (not shown) with a curing agent.

In the aluminum alloy rolled laminated board (1) for a small electronic device casing of the second aspect shown in Fig. 1(b), the synthetic resin film (30) (40) constituting the covering material (3) (4), for example, A polypropylene resin film, a polyester resin film, a polyamide resin film, a polyimide film, a polyethylene resin film, preferably a 2-axis extended polyethylene terephthalate resin film (PET) is used. , 2-axis extended nylon resin film (ONy), polyethylene resin film, 2-axis extended polyamide resin film, 2-axis extended polypropylene resin film (OPP), unstretched polypropylene resin film (CPP), unstretched nylon resin A film of any of the films (CNy).

In addition, the covering material (3) which is laminated on the outer surface of the outer surface of the small electronic device (the lower surface of Fig. 1(b)) on both sides of the aluminum alloy rolled sheet (2) is a synthetic resin film having a thickness of 10 to 200 μm ( 30) Preferably, the covering material (4) laminated on the inner surface of the outer surface of the small electronic device casing (the upper surface of Fig. 1(b)) is preferably a synthetic resin film (40) having a thickness of 10 to 100 μm.

More preferably, the coated material (3) which is laminated on the outer surface of the outer surface of the small electronic machine casing (the bottom surface of Fig. 1(b)) on both sides of the aluminum alloy rolled sheet (2) is made of a polyester resin having a thickness of 50 to 100 μm. A film or a polyimide film is further preferably a polyethylene-terephthalate resin film (PET) and a 2-axis extended polyethylene naphthalene resin film (PEN) having a thickness of 50 to 100 μm. ) or a 2-axis extended 6-nylon resin film (ONy) (30). As the film (30), a tensile strength of 180 to 330 MPa and a tensile elongation at break of 80 to 180% can be suitably used. Among them, a film (30) having a ratio of MD/TD of tensile strength or tensile elongation at break in the range of 0.8 to 1.2 can be suitably used.

Further, the coated material (4) which is a layer of the inner surface of the outer surface of the small electronic device (the upper surface of Fig. 1(b)) on both sides of the aluminum alloy rolled sheet (2) has a thickness of 10 to 100 μm (more preferably 20) Preferably, a polyethylene resin film, a polypropylene resin film or a polyamide resin film of ~80 μm) is preferably, more preferably, an unstretched polyethylene resin film, an unstretched polypropylene resin film (CPP), an extended polypropylene resin film. (OPP) or an extended nylon resin film (ONy) (40). As the film (40) described above, a Young's modulus system of 30 to 400 MPa can be suitably used.

Further, the covering material may be formed on at least one of the surfaces of the aluminum alloy rolled sheet (2) in more detail, and may be formed in an area layer constituting the outer surface of the outer casing, depending on the formability or the forming. The viewpoint of the protection of the surface of the outer casing after forming is as shown in Fig. 1, and it is preferable to form two layers of the aluminum alloy rolled sheet (2).

When the two-layer coating material of the aluminum alloy rolled sheet (2) is coated, the two covering materials stacked on each surface may be the same or different materials/thickness.

Moreover, when the bending strength of the aluminum alloy rolled sheet (2) is small or the thickness is small, the covering material is made When the synthetic resin film (30) (40) is used (refer to Fig. 1 (b)), when the bending strength of the aluminum alloy rolled sheet (2) is large or the thickness is large, if the coated material is a synthetic resin film, Since the surface of the molded article is wrinkled by cracking during the stretching process, the covering material is preferably composed of the laminated body (3) (4) (refer to Fig. 1 (a)).

For the lamination of the covering material (3) (4) on the surface of the aluminum alloy rolled sheet (2), it is necessary to remove the covering material (3) (4) from the surface after the outer casing is formed, as shown in Fig. 1, It is preferred to carry out the adhesive layer (34) (44). As the adhesive layer (34) (44), for example, an urethane-based adhesive, an acrylic adhesive, or a rubber-based adhesive can be used. The adhesion of the adhesive layer (34) (44) of the aluminum alloy rolled sheet (2) is preferably 0.5 to 15 N/25 mm (further preferably 1 to 10 N/25 mm). Here, the "adhesion" is represented by a 180° peeling adhesion based on JIS Z 0237:2000. If the adhesive force of the adhesive layer (34) (44) is less than 0.5N/25mm, there will be an unintentional coating (3) when the aluminum alloy rolled laminated sheet (1) before the outer shell is formed. ) peeling from the aluminum alloy rolled sheet (2), on the other hand, if the adhesive force of the adhesive layer (34) (44) exceeds 15 N/25 mm, the peeling material (3) (4) is peeled off after the outer shell is formed. In addition to the workability at the time, a part of the adhesive remains on the surface of the outer casing, causing problems such as grinding of the subsequent step.

The thickness of the covering material (3) (4) is preferably 0.05 to 1.5 times the thickness of the aluminum alloy rolled sheet (2), more preferably 0.2 to 1.0 times the same thickness.

Fig. 2 is a view showing a step of forming a small-sized electronic machine casing by subjecting the aluminum alloy rolled laminated sheet material (1) to a drawing process.

First, the aluminum alloy rolled laminated plate material (1) cut into a rectangular shape of a predetermined size is combined with the upper surface of the fixed female (die) (5) on the lower side of the mold (see Fig. 2(a)). Here, aluminum alloy The upper and lower surfaces of the gold rolled laminate sheet (1) are at least the outer side of the outer side of the outer casing, that is, the surface of the underlying cladding material (3), for example, coated with a bismuth-based lubricant, mineral oil, or synthetic petroleum. It is preferred to form a lubricant by a lubricant, whereby the formability can be further improved.

Further, when the movable male type (punch) (6) on the upper side of the mold is lowered, the portion excluding the peripheral portion of the aluminum alloy rolled laminated board (1) is pressed downward by the tip end portion of the male type (6). The straight portion of the peripheral portion is bent upward and is formed by the corner portion of the peripheral portion (see Fig. 2(b)). At this time, since the aluminum alloy rolled sheet (2) is coated on both sides by the covering material (3) (4), generation of wrinkles can be suppressed, and as a result, cracking does not occur. In addition, since the surface of the aluminum alloy rolled sheet (2) is not directly in contact with the female (5) and male (6), it is not damaged by friction.

Therefore, a small electronic machine casing (20) with a covering material (3) (4) is obtained. Since the surface of the small electronic device casing (20) is covered with the covering material (3) (4), it is not damaged by contact with other objects during storage or transportation, for example, and is maintained in a beautiful state.

Figure 3 shows a small electronic machine housing (20). The outer casing (20) is peeled off from the inner and outer surfaces of the small electronic machine casing (20) of the above-mentioned attached covering material (3) (4), and then subjected to partial cutting to complete forming. And further obtained by anodizing the surface.

The small electronic machine casing (20) is composed of a bottom wall (21) which is slightly square when viewed from a plane, and four side walls (22) which are individually stood by four sides of the bottom wall (21). The ends of adjacent side walls (22) are connected to each other, and the bottom wall (21) is surrounded by four side walls (22).

The height of the side wall (22) (in other words, the forming height) is 0.5 to 25 mm, preferably 1 to 15 mm, and more preferably 2 to 10 mm.

The angle of the side wall (22) is 90 to 150° with respect to the bottom wall (21) (the figure is about 90°). It is preferably 90 to 120°, more preferably 90 to 100°.

A curved path is attached to the boundary portion between the bottom wall (21) and the side wall (22), and a corner portion (22a) of the side wall (22) is also attached with a labyrinth. In these labyrinth portions, the fibrous crystal structure extends along the labyrinth.

The fibrous crystal structure can be confirmed by using a polarizing microscope: a section of the aluminum alloy rolled sheet (2) or the aluminum alloy rolled sheet (2) which is formed by the stranded outer casing (20).

Preferably, the fibrous crystal structure can be observed in the cross section cut from any direction such as 0°, 90°, 45°, or 135° with respect to the rolling direction of the aluminum alloy rolled sheet. The same can be observed in the folded portion or the corner portion.

Specifically, for example, as shown in Fig. 4 (a) and (b), the aluminum alloy rolled sheet (2) having a thickness of 0.25 mm is bent and processed into an inner labyrinth of 0 mm or 0.4 mm, with respect to such a bend. The folded material was observed using a polarizing microscope: the obtained cross section was cut from the direction (Y) of 90 (right angle) or 0 (parallel) with respect to the rolling direction (X). In this way, from the micrographs of Figures 5-8, the inner labyrinth: 0 mm, the cross-sectional direction with respect to the rolling direction: 90° (Fig. 5), the inner labyrinth: 0.4 mm, and the fracture direction with respect to the rolling direction. Surface direction: 90° (Fig. 6), internal meander diameter: 0 mm, cross-sectional direction with respect to the rolling direction: 0° (Fig. 7), internal meander diameter: 0.4 mm, cross-sectional direction with respect to the rolling direction: 0 In any of the sections (Fig. 8), the fibrous crystal structure extends along the labyrinth in a direction orthogonal to the thickness direction of the sheet.

[Examples]

Next, specific embodiments of the present invention will be described. However, the invention is not limited to the embodiments.

<Example 1>

Si: 0.2 to 0.6% by mass, Mg: 0.45 to 0.9% by mass, Fe: 0.35% by mass or less, Cr: 0.1% by mass or less, and Zn: 0.1% by mass The aluminum alloy ingot formed of the residue Al and the unavoidable impurities was homogenized at 580 ° C for 10 hours, and the surface was cut, and preheated at 500 ° C to start the inter-heat rolling. The final path start temperature of the inter-heat rolling was 400 ° C, and after the path, it was cooled at a rate of 80 ° C / min. Thereafter, heat treatment was performed at 240 ° C for 4 hours. Thereafter, cold rolling was performed at a reduction ratio of 86%. Thereby, an aluminum alloy rolled sheet having a thickness of 1 mm with a 0.2% proof endurance of 310 MPa and a breaking elongation of 7% was obtained.

The cross section of the above-mentioned sheet material was observed by an optical microscope and a polarizing lens to find a fibrous crystal structure extending in a direction orthogonal to the thickness direction.

Further, the underside of the aluminum alloy rolled sheet constituting the outer surface of the small electronic device casing is laminated with an adhesive layer formed of an acrylic adhesive, and the coated material is a single side of the aluminum foil having a thickness of 120 μm. The adhesive layer of the urethane resin and hexamethylene diisocyanate is laminated with the unstretched polypropylene resin film having a thickness of 30 μm, and the other side is laminated with the unstretched polypropylene resin film having a thickness of 200 μm by the adhesive layer. A layered body.

Further, the upper surface of the aluminum alloy rolled sheet constituting the inner surface of the outer casing of the small electronic device was laminated with an adhesive layer formed of an acrylic adhesive, and the coated material was a nylon resin film having a thickness of 30 μm.

The aluminum alloy rolled laminated sheet obtained therefrom was cut into a rectangular shape of 150 mm in length, 82 mm in width, and a tortuous diameter of 14.5 mm in the corner portion to prepare a molding material of Example 1.

<Example 2>

Si: 0.4% by mass or less, Mn: 0.4 to 0.6% by mass, Mg: 4.0 to 4.9 mass%, Fe: 0.4 mass% or less, Cr: 0.05 to 0.25 mass%, Zn: 0.25 mass% or less, and formed of residual portion Al and unavoidable impurities The aluminum alloy ingot was homogenized at 580 ° C for 10 hours, and the surface was cut, and preheated at 500 ° C to start the inter-heat rolling. The final path start temperature of the inter-heat rolling was 400 ° C, and after the path, it was cooled at a rate of 80 ° C / min. Thereafter, heat treatment was performed at 240 ° C for 4 hours. Thereafter, the mixture was subjected to cold rolling at a reduction ratio of 79%, and finally blunt at 130 ° C for 4 hours. Thereby, an aluminum alloy rolled sheet having a thickness of 1.5 mm and a breaking elongation of 7% of 0.2% was obtained.

The cross section of the above-mentioned sheet material was observed by an optical microscope and a polarizing lens to find a fibrous crystal structure extending in a direction orthogonal to the thickness direction.

Further, the upper and lower surfaces of the aluminum alloy rolled sheet were laminated with the covering material by an adhesive layer formed of an acrylic adhesive, and the covering material was a nylon resin film having a thickness of 90 μm.

The aluminum alloy rolled laminated sheet obtained therefrom was cut into a rectangular shape of 150 mm in length, 82 mm in width, and a tortuous diameter of 14.5 mm in the corner portion to prepare a molding material of Example 2.

<Example 3>

Si: 0.4% by mass or less, Mg: 2.1 to 2.9% by mass, Fe: 0.5% by mass or less, Cu: 1.2 to 2.0% by mass, and Mn: 0.3% by mass Hereinafter, Cr: 0.18 to 0.28 mass%, Zn: 5.1 to 6.1 mass%, and an aluminum alloy ingot formed by the residual portion Al and the unavoidable impurities, by the same procedure as in the second embodiment. The condition was rolled to obtain an aluminum alloy rolled sheet having a thickness of 1.5 mm and a fracture elongation of 9% of 0.2%.

The cross section of the above-mentioned plate can be found in the thickness and thickness by observation with an optical microscope and a polarizing lens. A fibrous crystal structure extending in a direction orthogonal to the direction.

Further, the underside of the aluminum alloy rolled sheet which constitutes the outer surface of the outer casing of the small electronic device is laminated with an adhesive layer formed of an acrylic adhesive, and the coated material is a nylon resin film having a thickness of 90 μm.

The aluminum alloy rolled laminated sheet obtained therefrom was cut into a rectangular shape of 150 mm in length, 82 mm in width, and a tortuous diameter of 14.5 mm in the corner portion to prepare a molding material of Example 3.

<Example 4>

An aluminum alloy rolled sheet similar to that of Example 1 was prepared.

Further, the underside of the aluminum alloy rolled sheet which constitutes the outer surface of the outer casing of the small electronic device is laminated with an adhesive layer formed of an acrylic adhesive, and the coated material is a nylon resin film having a thickness of 90 μm.

The aluminum alloy rolled laminated sheet obtained therefrom was cut into a rectangular shape of 150 mm in length, 82 mm in width, and a tortuous diameter of 14.5 mm in the corner portion to prepare a molding material of Example 4.

<Comparative Example 1>

Preparation: Si: 0.4% by mass or less, Mn: 0.4 to 1.0% by mass, Mg: 4.0 to 4.9% by mass, Fe: 0.4% by mass or less, Cr: 0.05% 0.25 mass%, Zn: 0.25 mass% or less, and an aluminum alloy formed of a residual portion Al and an unavoidable impurity, and an aluminum alloy having a thickness of 230 mm and a tensile elongation of 14% and a thickness of 2 mm are extruded. Plate. The sheet material is extruded into a molded body and does not have a fibrous crystal structure extending in a direction orthogonal to the thickness direction.

Further, the aluminum alloy was extruded on the lower surface of the sheet material, and the adhesive layer formed of the acrylic adhesive was separately laminated with the covering material, and the covering material was a nylon resin film having a thickness of 90 μm.

The aluminum alloy thus obtained is extruded from the laminated board The molding material of Comparative Example 1 was produced by cutting into a rectangular shape of 150 mm in length, 82 mm in width, and 14.5 mm in corner corner.

<Comparative Example 2>

Preparation: Si: 0.4% by mass or less, Mg: 2.1 to 2.9% by mass, Fe: 0.5% by mass or less, Cu: 1.2 to 2.0% by mass, Mn: 0.3 mass % or less, Cr: 0.18 to 0.28 mass%, Zn: 5.1 to 6.1 mass%, and the aluminum alloy formed by the residual portion Al and the unavoidable impurities, the 0.2% proof stress is 510 MPa, and the fracture is 510 MPa. An aluminum alloy having an elongation of 11% and a thickness of 1.5 mm was extruded. The sheet material is extruded into a molded body and does not have a fibrous crystal structure extending in a direction orthogonal to the thickness direction.

Further, the aluminum alloy extruded sheet was cut into a rectangular shape of 150 mm in length, 82 mm in width, and a tortuous diameter of 14.5 mm in the corner portion to prepare a molding material of Comparative Example 2.

<Comparative Example 3>

Si: 0.2 to 0.6% by mass, Mg: 0.45 to 0.9% by mass, Fe: 0.35% by mass or less, Cr: 0.1% by mass or less, and Zn: 0.1% by mass In the following, the aluminum alloy ingot made of the residue Al and the unavoidable impurities was homogenized at 580 ° C for 10 hours, and then the surface was cut, and preheated at 500 ° C to start the inter-heat rolling. The final path start temperature of the inter-heat rolling was 400 ° C, and after the path, it was cooled at a rate of 80 ° C / min. Thereafter, heat treatment was performed at 240 ° C for 4 hours. Thereafter, the mixture was subjected to cold rolling at a reduction ratio of 57%, and then heat-treated at 250 ° C for 2 hours. Thereby, an aluminum alloy pressure having a thickness of 3 mm with a 0.2% proof endurance of 150 MPa and an elongation at break of 14% was obtained. Extend the sheet. The sheet material is subjected to natural aging treatment in cold rolling, and does not have a fibrous crystal structure extending in a direction orthogonal to the thickness direction.

Further, on the lower surface of the aluminum alloy rolled sheet, the adhesive layer formed of the acrylic adhesive was separately laminated with the covering material, and the covering material was a nylon resin film having a thickness of 30 μm.

The aluminum alloy rolled laminated sheet obtained therefrom was cut into a rectangular shape of 150 mm in length, 82 mm in width, and a tortuous diameter of 14.5 mm in the corner portion to prepare a molding material of Comparative Example 3.

<Comparative Example 4>

Preparation: Si: 0.2 to 0.6% by mass, Mg: 0.45 to 0.9% by mass, Fe: 0.35% by mass or less, Cr: 0.1% by mass or less, Zn: 0.1 mass An aluminum alloy rolled sheet having a thickness of 2 mm with a 0.2% proof endurance of 145 MPa and a breaking elongation of 12%, which is made of an aluminum alloy having a residual portion of Al and an unavoidable impurity. For the sheet, the sheet is pressed for cold rolling (33% reduction), and there is no fibrous crystal structure extending in the direction orthogonal to the thickness direction.

Further, on the lower surface of the aluminum alloy rolled sheet, the adhesive layer formed of the acrylic adhesive was separately laminated with the covering material, and the covering material was a nylon resin film having a thickness of 30 μm.

The aluminum alloy rolled laminated sheet obtained therefrom was cut into a rectangular shape of 150 mm in length, 82 mm in width, and a tortuous diameter of 14.5 mm in the corner portion to prepare a molding material of Comparative Example 4.

<Formation of small electronic machine casing>

The molding materials of Examples 1 to 4 and Comparative Examples 1 to 4 were subjected to a drawing process by using a stretching apparatus shown in Fig. 2, and were formed into a longitudinal direction of 140.5 mm, a width of 70.5 mm, and a side wall height (forming). A small electronic machine case with a height of 7 mm and a corner diameter of 2 mm at the corner of the side wall. The angle of the side wall is 90° with respect to the bottom wall.

The molded outer casings were observed with the naked eye. The molded materials of Examples 1 to 4 were free from wrinkles or cracks in the corner portions of the side walls, and the outer surfaces of the side walls were not found to be in contact with the lower mold. .

On the other hand, in the outer casing of the molding materials of Comparative Examples 1 to 4, wrinkles or cracks were formed in the corner portions of the side walls. Further, when the molded materials of Comparative Examples 1, 3, and 4 were formed into a casing, the outer side walls of the casings were not found to have scratches, but the outer surface of the outer casing of Comparative Example 2 was formed with a flaw caused by contact with the lower mold.

[Industrial use possibility]

The present invention can be suitably utilized for housings of a tablet computer terminal, a portable terminal device, a notebook computer, a mobile phone, a portable electronic device, a digital camera, and the like.

(1)‧‧‧Aluminum rolled laminated sheets

(2)‧‧‧Aluminum alloy rolled sheet

(3) (4) ‧‧‧ Covering materials

(5) ‧ ‧ fixed female

(6) ‧‧‧ movable male

(20)‧‧‧Small electronic machine housing

Claims (13)

An aluminum alloy calendered laminated board for a small electronic machine casing, which is formed by a stranding process and formed into an aluminum alloy rolled laminated board of a small electronic machine casing, characterized in that the aluminum alloy rolled sheet and the covering material are composed of the aluminum alloy The rolled sheet has a 0.2% proof stress of 200 MPa or more; the coated material is laminated on at least one of the two faces of the aluminum alloy rolled sheet; and the coated material is a synthetic resin film and a synthetic resin film on the two-layer layer of the metal foil. At least one of the laminates is formed. The aluminum alloy rolled laminated board for a small electronic device casing according to the first aspect of the invention, wherein the aluminum alloy rolled sheet has a fibrous crystal structure extending from a direction orthogonal to the thickness direction. The aluminum alloy rolled laminated board for a small electronic machine casing according to the first aspect of the patent application, wherein the aluminum alloy rolled sheet is made of an Al-Mn-Mg alloy, an Al-Si-Mg alloy, and an Al- The aluminum alloy of any one of the Zn-Mg alloys; and the Al-Mn-Mg alloy contains Mn: 0.2 to 0.7% by mass, and Mg: 2.0 to 5.0% by mass. It is composed of the residue Al and the unavoidable impurities; the Al-Si-Mg alloy contains Si: 0.2 to 0.8% by mass, Mg: 0.4 to 1.2% by mass, and is inevitably left by the residue Al and The Al-Zn-Mg-based alloy contains Zn: 4.0 to 6.5 mass%, Mg: 0.5 to 3.0 mass%, and is formed of the residue Al and the unavoidable impurities. Aluminum alloy rolling for small electronic machine casing as described in item 2 of the patent application scope a laminated board, wherein the aluminum alloy rolled sheet is made of an aluminum alloy of any one of an Al-Mn-Mg alloy, an Al-Si-Mg alloy, and an Al-Zn-Mg alloy; and Al- The Mn-Mg alloy contains Mn: 0.2 to 0.7% by mass, Mg: 2.0 to 5.0% by mass, and is formed of residual Al and unavoidable impurities; and Al-Si-Mg alloy, It contains Si: 0.2-0.8 mass%, Mg: 0.4-1.2 mass%, and is formed by residual Al and unavoidable impurities; Al-Zn-Mg alloy contains Zn: 4. 0 to 6.5% by mass, Mg: 0.5 to 3.0% by mass, and formed by the residue Al and the unavoidable impurities. The aluminum alloy rolled laminated board for a small electronic device casing according to the first aspect of the invention, wherein the thickness of the covering material is 0.05 to 1.5 times the thickness of the aluminum alloy rolled sheet. The aluminum alloy rolled laminated board for a small electronic machine casing as described in the first aspect of the patent application, wherein the thickness of the aluminum alloy rolled sheet is 0.5 to 3.5 mm. The aluminum alloy rolled laminated sheet material for a small electronic device casing according to the first aspect of the invention, wherein the aluminum alloy rolled sheet has a surface on the outer surface of the small electronic device casing, and has a polyester layer having a thickness of 50 to 100 μm. A resin film or a polyamide resin film is used as a covering material. An aluminum alloy rolled laminated sheet material for a small electronic device casing according to the fourth aspect of the invention, wherein the aluminum alloy rolled sheet has a surface on the outer surface of the small electronic device casing, and a polyester layer having a thickness of 50 to 100 μm is laminated. A resin film or a polyamide resin film is used as a covering material. Aluminum alloy rolling for small electronic machine casing as described in item 1 of the patent application scope A laminated board in which a surface of an inner surface of a small electronic machine casing is formed on both sides of an aluminum alloy rolled sheet, and a polyethylene resin film having a thickness of 10 to 100 μm, a polypropylene resin film or a polyimide film is used as a covering material. . A small electronic device casing with a covering material, characterized in that the aluminum alloy rolled laminated sheet material for a small electronic machine casing described in any one of claims 1 to 9 is subjected to a drawing process, and at least one of the inner and outer surfaces The side surface is covered with a synthetic resin film or a laminate to form a covering material. A small electronic device casing characterized in that the aluminum alloy rolled laminated sheet material for a small electronic machine casing described in any one of claims 1 to 9 is subjected to a drawing process, and at least one of the inner and outer surfaces is removed. Covered material covered. The small electronic device casing according to claim 11, wherein the bottom wall has a side wall standing from a periphery of the bottom wall, and the height of the side wall is 0.5 to 25 mm, and the side wall is opposite to the bottom wall. The angle is 90~150°. A method of forming a small-sized electronic device casing, which is characterized in that the aluminum alloy rolled laminated sheet material for a small electronic machine casing described in any one of claims 1 to 9 is subjected to a drawing process.