JPH09123209A - Enclosure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent occurrence of shape failure even if thin-wall design is employed and increase stiffness by providing a frame and a resin layer formed with the frame embedded in its inside. SOLUTION: When a frame 13 is inserted in the cavity of a mold, the volume of the cavity generally decreases, and resin becomes difficult to flow, however, the resin charged in the cavity flows along a flow passage because the flow passage is formed at the frame 13. Therefore, the resin flows over the cavity, and the whole part of the inner surface and outer surface of the frame 13 is covered without any generation of uncharged parts. An enclosure 11 is formed into a structure whose frame 13 is inserted in a resin layer 12. It is thus, possible to prevent production of inferior parts caused by uncharged parts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a housing device used for electric appliances, particularly information equipment and the like which are required to be small and lightweight.

[0002]

2. Description of the Related Art Recently, information devices such as personal computers have been required to be smaller and lighter, and various improvements have been made accordingly. It is considered to reduce the thickness of the housing to deal with it.

The casing is made of a light metal such as an aluminum alloy or a resin, but in many cases, a manufacturing method of using a resin for injection molding is adopted in view of mass productivity and price.

When the wall thickness of a casing formed of resin is reduced, various problems occur with the reduction in wall thickness.
For example, thinning reduces the rigidity of the housing,
When the housing 1 is box-shaped as shown in FIG. 10, the upper wall 1a may warp inward, and the peripheral wall 1b may also warp inward, resulting in a poor appearance.

In order to prevent the warp of the housing 1, a reinforcing rib 3 is provided on the inner surface of the housing 1 as shown in FIG. However, when the reinforcing rib 3 is provided,
Since the sink mark 4 is formed on the upper surface, the appearance defect is caused also in that case.

On the other hand, the flow resistance of the molten resin injected into the cavity in the mold increases as the casing becomes thinner. Therefore, even if a high pressure is applied to the molten resin, the molten resin may not flow over the entire cavity and an unfilled portion may occur, which may lead to defective products.

[0007]

As described above, when the housing is made thin in order to reduce the weight of the housing, warping may occur due to a decrease in rigidity, resulting in poor appearance. If a reinforcing rib is provided to improve the quality, a sink mark is generated at that portion, which also leads to poor appearance.

Further, since the resistance of the resin flowing through the cavity is increased due to the thinning, the molten resin may not flow over the entire cavity, resulting in an unfilled portion, which may lead to defective products.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a housing device which does not cause a defective shape even if it is made thin and can have rigidity. To do.

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the invention of claim 1 is a box device having a thin-walled structure, wherein a frame and the frame are provided inside. And a resin layer formed by being embedded therein.

The invention of claim 2 is characterized in that the frame is provided with a flow path for circulating a molten resin when the resin layer is molded. According to a third aspect of the present invention, in a thin-walled casing device formed in a box shape, the frame device includes a frame and a resin sheet that is adhered and fixed to cover the outer surface of the frame. It is characterized by

According to a fourth aspect of the present invention, in the third aspect of the present invention, an introduction groove for introducing an adhesive for fixing the resin sheet to the frame is provided on the outer surface of the frame. It is characterized by being formed.

According to a fifth aspect of the present invention, in a thin-walled casing device formed in a box shape, a two-layer structure of an integrally molded outer resin layer and inner resin layer is formed. The linear expansion coefficient of the resin forming the layer is smaller than the linear expansion coefficient of the resin forming the inner resin layer.

According to a sixth aspect of the invention, in the fifth aspect of the invention, a convex portion is formed on one of the inner surface of the inner resin layer and the outer surface of the outer resin layer, and the convex portion enters the other surface. It is characterized in that a recess is formed.

According to the first aspect of the invention, since the frame is inserted in the resin layer, the rigidity of the frame makes it difficult to deform even if the whole is thinned. According to the second aspect of the present invention, the flow path formed in the frame facilitates the flow of the molten resin, so that it is possible to prevent the unfilled portion from occurring.

According to the invention of claim 3, since the frame is covered with the resin sheet, not only can the thickness be reduced, but also the frame can be made thin.
It is possible to provide strength that does not easily deform due to the rigidity of the frame. According to the invention of claim 4, the adhesive can be surely introduced between the frame and the resin sheet by the introduction groove formed in the frame.

According to the fifth aspect of the present invention, the housing has a two-layer structure, and by using materials having different linear expansion coefficients for these layers, it is possible to correct the warpage that occurs during molding.
According to the invention of claim 6, the outer resin layer and the inner resin layer are bonded together by the projections and recesses fitted into each other, and the bonding strength is improved, so that these layers do not separate.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show a first embodiment of the present invention, in which the housing 11 of the first embodiment is an ABS,
A frame 13 is inserted into a resin layer 12 made of a thermoplastic resin such as PC or PP. That is, the frame 11 is formed by holding the frame 13 in a cavity of a mold (not shown) and then injecting resin into the cavity. When the thickness of the housing 11 is, for example, 1 mm, the thickness of the frame 13 is set to about 0.4 mm, and the thickness of the resin layer 12 is set to about 0.6 mm or less.

The frame 12 is made of a material having higher rigidity than a thermoplastic resin, for example, a metal such as an aluminum alloy, magnesium or titanium, or a thermosetting resin, and is formed in a box shape having an open lower surface. .
A plurality of flow paths 14 are formed in the frame 13 in order to facilitate the flow of the resin over the entire inner surface and outer surface of the frame 13 when the resin layer 12 is molded.

That is, the flow path 14 is formed by the frame 1
3, a main groove 14a formed across the upper wall and the side wall in the width direction, and a sub groove 14b branched from the main groove 14a in the longitudinal direction of the frame 13.

When the frame 13 having the above structure is held in the cavity of the mold and a thermoplastic resin is injected into the cavity, the resin passes through the flow path 14 formed in the frame 13 and the frame is formed. Flow over the entire surface of 13.

That is, normally, the cavity of the mold is framed.
When the frame 13 is inserted, the volume of the cavity is reduced and it becomes difficult for the resin to flow. However, since the flow path 14 is formed in the frame 13, the resin injected into the cavity is flowed above. Flows along path 14. Therefore, the resin flows over the entire cavity, so that the inner surface and the outer surface of the frame 13 are entirely covered without an unfilled portion.

That is, the casing 11 has a structure in which the frame 13 is inserted in the resin layer 12. Therefore, even if the housing 11 is made thin, a defective product due to the unfilled portion does not occur.

Further, according to the housing 11 having the above structure, the inserted frame 13 can provide rigidity even if the wall thickness is reduced in order to reduce the weight. Therefore, not only can the warp be prevented from occurring after molding,
Unlike the case where the reinforcing rib is provided to improve the rigidity, the sink mark does not occur on the outer surface and the appearance shape is not damaged. If the injection compression method is used together when the resin layer 12 is molded, the resin filling state can be further improved.

3 to 5 show a second embodiment of the present invention. The housing 21 of this embodiment is formed of a frame 22 and a resin sheet 23 covering the outer surface of the frame 22.

The frame 22 is made of an aluminum alloy having a high bending rigidity, a metal such as magnesium or titanium,
Alternatively, it is formed of a thermosetting resin or the like having higher rigidity than a thermoplastic resin. The frame 22 has a thickness of 0.5 m
At about m, the aperture ratio is set to 95%, that is, the area occupied by the ribs 22a in the surface area of the frame 22 is set to 5%. As a result, the entire housing 21 is
The weight could be reduced to about 25% as compared with the case of molding with S resin.

As shown in FIG. 4, the resin sheet 23 has an aluminum foil 23a having a thickness of 100 μm and a thickness of 200 μm.
The two PP sheets 23b are joined together, and the thickness is 500μ.
It has a m-laminate structure. This resin sheet 2
The reference numeral 3 is formed into a shape smaller than the frame 22 by about 1% by vacuum forming or stretch forming. Therefore,
Since the resin sheet 23 is stretched when the resin sheet 23 is covered with the frame 22, it is possible to eliminate the shape error between the frame 22 and the resin sheet 23. it can.

The resin sheet 23 is used for the frame 22.
It is adhered and fixed after being applied to. That is, the frame
As shown in FIG. 5, an introduction groove 22b is vertically formed on the outer peripheral surface of the rib 22a located on the outer periphery of the lower end of the frame 22.

Therefore, by immersing the lower end of the frame 22 covered with the resin sheet 23 in a liquid adhesive (not shown), the adhesive is capillarized from the introduction groove 22b to the frame 22. The resin sheet 23 can be adhered to the frame 22 by introducing the resin sheet 23 between the resin sheet 23 and the resin sheet 23.

As described above, according to the casing 21 in which the frame 22 is covered with the resin sheet 23, the frame 22 is formed.
Is 0.5 mm and the thickness of the resin sheet 23 is also 0.5 mm, so that the overall thickness can be a thin structure of 1 mm.

Even if the housing 21 has a thin wall structure, the frame 22 maintains its rigidity so that it is not easily deformed, and the rib 22a of the frame 22 occupies 5% of the area, which makes it lightweight. It can be realized. Furthermore, the resin sheet 23
Is a laminate structure using the aluminum foil 23a,
It is possible to prevent leakage of electromagnetic waves from the housing 21.

A rib 22a at the lower end of the frame 22 is also provided.
In addition, since the introduction groove 22b for introducing the adhesive between the frame 22 and the resin sheet 23 is formed by utilizing the capillary phenomenon, it is possible to easily and surely perform the adhesive fixing of the both. It will be possible.

6 to 9 show a third embodiment of the present invention. The housing 31 of this embodiment has a two-layer structure in which an outer resin layer 32 and an inner resin layer 33 are joined. The outer resin layer 32 is made of a material having a smaller linear expansion coefficient than the inner resin layer 33. For example, when ABS resin is used for the outer resin layer 32, PP resin is used for the inner resin layer 33.

As shown in FIG. 7A, one of the joined outer resin layer 32 and inner resin layer 33, in this embodiment the outer resin layer 33, is provided with a groove-like recess 34 on the outer surface thereof. On the inner surface of the outer resin layer 32, a convex portion 35 that fits into the concave portion 34 is formed. Thereby, the joined outer resin layer 32 and inner resin layer 33 are fixed without peeling. Note that, as shown in FIG. 7B, a convex portion 35 may be formed on the outer surface of the inner resin layer 33 and a concave portion 34 may be formed on the inner surface of the outer resin layer 32.

By making the coefficient of linear expansion of the outer resin layer 32 smaller than that of the inner resin layer 33, the two members joined as shown in FIG. 8 (a) are flat in a high temperature state during molding. However, when the temperature drops after molding,
As shown in (b), the inner resin layer 33 is curved so as to be on the inner side.

On the other hand, as shown in FIG. 10, when the casing 1 is molded without the two-layer structure, the upper wall 1a and the peripheral wall 1b of the casing 1 generally warp inward as described above. That is, the case 1
The inner side has a larger elongation than the outer side.

Therefore, as in the present invention, the outer resin layer 32
When the coefficient of linear expansion of the inner resin layer 33 is made smaller than that of the inner resin layer 33, the outer resin layer 3 is kept in a temperature lowered state after molding.
The growth of 2 is larger. Therefore, the upper wall 31 of the housing 31
Since the a and the peripheral wall 31b generate a outwardly convex warping force, the originally generated inwardly convex warping force cancels each other out to form a molded casing 31. Almost no warpage occurs in the upper wall 31a and the peripheral wall 31b.

A method of molding the above-mentioned two-layer structure casing 31 shown in FIGS. 9A to 9C is shown. The mold 41 for molding the casing 31 includes a movable mold 42, a first fixed mold 43, and a second mold 42.
Of the fixed mold 44. First, as shown in FIG. 9A, PP resin is injected from the cylinder 46 into the first cavity 45 formed by joining the first fixed mold 43 to the movable mold 42. Thereby, the first cavity 45
The inner resin layer 33 is formed on the inner surface.

Next, as shown in FIG. 9 (b), the first fixed mold 43 is removed while leaving the inner resin layer 33 molded in the movable mold 42, and as shown in FIG. 9 (c). Then, the movable mold 42 is joined to the second fixed mold 44. As a result, the second cavity 47 is formed between the inner resin layer 33 left on the movable mold 42 and the second fixed mold 44. ABS resin is injected into the second cavity 47. As a result, the outer resin layer 32 is integrally formed on the outer surface of the inner resin layer 33.

[0040]

As described above, according to the first aspect of the present invention, since the frame is inserted into the resin layer to form the housing, the rigidity of the frame reduces the thickness of the housing. However, it is possible to make the structure difficult to deform. That is, it is possible to prevent the reduction in strength due to the thinning of the housing.

According to the invention of claim 2, in the invention of claim 1, a flow path is formed in the frame to facilitate the flow of the resin during molding. Therefore, even if the housing is thinned, the molten resin can be entirely flowed through the flow path, so that a portion not filled with the resin is generated and defective molding is not caused.

According to the invention of claim 3, since the frame is covered with the resin sheet, not only can the thickness be reduced, but also the frame can be made thin.
The rigidity of the frame can maintain the strength of the thinned housing.

According to the invention of claim 4, in the case of claim 3, since the introduction groove for introducing the adhesive agent by the capillarity is formed in the frame, the frame and the resin sheet are formed.
It is possible to introduce an adhesive between the two and to securely and easily bond both of them.

According to the fifth aspect of the invention, the housing has a two-layer structure, and materials having different linear expansion coefficients are used for each of these layers. Therefore, since the warp generated in the housing by the resin molding can be corrected, as a result, it is possible to mold the housing without the warp.

According to the invention of claim 6, in the invention of claim 5, since the outer resin layer and the inner resin layer are coupled by the convex portion and the concave portion fitted into each other, the bonding strength between them is It can improve and prevent peeling.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a housing showing a first embodiment of the present invention.

FIG. 2 is a perspective view of the frame.

FIG. 3 is an exploded perspective view of a housing showing a second embodiment of the present invention.

FIG. 4 is an enlarged cross-sectional view showing a part of the housing of the same.

FIG. 5 is a perspective view of a portion of the housing in which an introduction groove is formed.

FIG. 6 is a sectional view of a housing showing a third embodiment of the present invention.

7A and 7B are partially enlarged cross-sectional views.

FIG. 8 is an explanatory view of a deformed state in the case of a two-layer structure.

FIG. 9 is an explanatory view of a procedure for molding a housing having a two-layer structure.

FIG. 10 is an explanatory diagram of a state where a conventional case warps.

FIG. 11 is an explanatory diagram of a sink mark occurrence state.

[Explanation of symbols]

11, 21, 31 ... Casing, 12 ... Resin layer, 13, 22 ...
Frame, 14 ... Channel, 23 ... Resin sheet, 22b ...
Introduction groove, 32 ... Outer resin layer, 33 ... Inner resin layer, 34 ...
Concave portion, 35 ... convex portion.

Claims (6)

[Claims] 1. A casing device having a thin-walled structure formed in a box shape, comprising a frame and a resin layer formed by embedding the frame inside. Body device. 2. The casing device according to claim 1, wherein the frame is provided with a flow path for allowing a molten resin to flow when the resin layer is molded. 3. A box-shaped thin-walled casing device comprising a frame and a resin sheet which is adhered and fixed to cover the outer surface of the frame. Characteristic enclosure device. 4. An outer surface of the frame is formed with an introduction groove for introducing an adhesive for adhering and fixing the resin sheet to the frame. Three
The casing device described. 5. A thin-walled casing device formed in a box shape, which has a two-layer structure of an outer resin layer and an inner resin layer integrally molded, and a resin forming the outer resin layer. The linear expansion coefficient of is smaller than the linear expansion coefficient of the resin forming the inner resin layer. 6. A convex portion is formed on one of the inner surface of the inner resin layer and the outer surface of the outer resin layer, and a concave portion into which the convex portion enters is formed on the other surface. The housing device according to claim 5.