JP2016074115A - Housing of electronic apparatus and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase strength and ensure a function by forming a closed cross section without depending on gas assist molding or molding using a slide core sliding widely inside a housing.SOLUTION: A method for manufacturing a housing of an electronic apparatus includes: preparing a molding mold 50 including a stationary mold 51, a movable mold 52, a first slide core 53 and a second slide core 54 sliding in a direction perpendicular to a direction clamping these molds and in a direction along a peripheral edge of a housing 3, and another piece 55 slide-moving in a direction intersecting both slide cores 53, 54 to be inserted with their tips 53a, 54a; and injecting a molten resin into a cavity with the tips 53a, 54a being supported by the another piece 55 to mold a frond-side cabinet 3 having a closed cross section continuously formed with an internal space 11 at a peripheral edge by both slide cores 53, 54.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electronic device casing made of a resin molded product and a method for manufacturing the same.

  Conventionally, a molding method of a resin molded product in which a hollow portion is formed using a slide core is known. For example, as in Patent Document 1, a molding method of a resin molded product is known in which an undercut is eliminated by filling a thick portion with meat. In this method, in order to prevent sink marks when the molten resin hardens, pressurization of pressurized fluid is performed as the slide core moves backward.

JP-A-9-61049

  By the way, as illustrated in FIGS. 9 and 10, a surface 100 (shown by a thick line in FIG. 10) necessary for the electronic device is provided on the housing 103 by becoming a mating surface with other components, and cooling. In order to prevent the sinking that the surface is sometimes dented, it is necessary to provide an undercut portion 101 that is undercut with respect to the unillustrated movable mold and fixed mold blanking directions (indicated by white arrows). For this purpose, the first slide core 104, the second slide core 105, and the inclined core 106 must be provided in accordance with the shape of the housing 103. In FIG. 9A, inside the housing 103, the first slide core 104 is slidable in the left-right direction, the second slide core 105 is slidable in the up-down direction, and the inclined core 106 is The sliding movement is possible in an oblique direction.

  Specifically, after injecting molten resin, filling the cavity, cooling, and then releasing the mold, first, the first slide core 104 and the second slide core 105 are mounted from the state shown in FIG. It slides to the inner side of the body 103, and it will be in the state of FIG.9 (b).

  Next, from the state of FIG. 9B, the inclined core 106 at the corner is moved obliquely with the inclined pin in accordance with the removal (protrusion) of the housing 103.

  Then, as shown in FIG. 9C, the inclined core 106 is displaced in the thickness direction by pushing the inclined pin in accordance with the removal of the housing 103, thereby avoiding the first slide core 104 and the second slide core 105. be able to. For example, the inclined core 106 moves to the near side in FIG.

  As described above, the conventional method for molding a resin molded product has a problem in that the mold structure is complicated, resulting in an increase in cost and a decrease in the reliability of the mold. In addition, since a slide core is required on the inner side over almost the entire circumference, structures such as bosses and ribs cannot be arranged in the vicinity of the outer circumference, which is a great design restriction.

  In addition, since molding with pressurization of pressurized fluid in Patent Document 1 cannot arbitrarily control the shape of the cavity, it is necessary to have a large number of irregularities and to finely control the thickness and the shape of the cavity to prevent sink marks and ensure strength. It cannot be applied to a case of an electronic device having a certain size.

  The present invention has been made in view of the above points, and the object of the present invention is to form a closed cross-section without relying on gas assist molding or molding using an inner slide core to improve strength and secure functions. Is to do.

  In order to achieve the above object, in the present invention, the molten resin is injected into the cavity inside the mold while the tip of the slide core is supported by another piece of the mold.

Specifically, in the present invention, in a method for manufacturing a casing of an electronic device made of a resin molded product,
A movable mold, a fixed mold, a slide core that slides in a direction perpendicular to the mold clamping direction of the movable mold and the fixed mold and along the peripheral edge of the casing, and a slide movement that intersects the slide core. Preparing a mold having a separate piece into which the tip of the slide core is inserted; and
The casing having a closed cross-section in which molten resin is injected into the cavity of the mold while the tip of the slide core is supported by the separate piece, and an inner space formed by the slide core is continuously formed at the periphery. And a molding step of molding.

  According to the above configuration, the inner space is continuously formed by the slide core at the peripheral edge of the casing, so that the overall thickness is made as uniform as possible, and dents caused by molding shrinkage can be avoided. Consists of a closed cross-section with an internal space corresponding to the slide core by forming the peripheral edge of the housing with resin injected into the cavity formed in the area sandwiched between the outer periphery of the slide core, the movable mold and the fixed mold Therefore, the strength is increased while preventing sink marks. Even when the slide core becomes long, the tip of the slide core is supported by a separate piece at the time of injection molding, so that molding defects due to the swing of the slide core can be avoided. In addition, another piece may be comprised with a movable type or a fixed type | mold, and may be comprised with another slide core. In addition, since the slide core is slid in the direction along the periphery of the casing instead of sliding the slide core to the inside of the casing, it is easy to provide a structure such as a boss inside the casing. The shape of the housing is not particularly limited, but a linear outer surface formed by the slide core is formed on any side surface.

  The housing of the present invention has a closed cross section in which a continuous internal space formed by a slide core is formed on at least one side of a rectangular plate shape, and a position corresponding to the tip of the slide core on the back side of the internal space In addition, a communication hole opened in a direction intersecting with the extending direction of the internal space is closed with an adhesive.

  According to the above configuration, the communication hole formed by a separate piece for supporting the tip of the slide core at the time of molding is formed with an adhesive, having a high-periphery peripheral edge configured with a substantially identical thickness and a closed cross section. A sealed and highly waterproof casing is obtained.

  As described above, according to the present invention, the molten resin is injected into the cavity inside the mold while the tip of the slide core is supported by another piece, and the inner space is continuously formed at the periphery by the slide core. The above-mentioned housing having a closed cross section is molded, so that the strength is improved and the function is achieved by forming the closed cross section without relying on gas assist molding or molding using a slide core that slides widely inside the housing. Ensuring can be done.

It is an expanded sectional view which shows the time of shaping | molding of the part corresponding to the II line | wire of FIG. The smart phone which concerns on embodiment of this invention is shown, (a) is the perspective view seen from the front side, (b) is the perspective view seen from the back side. It is a disassembled perspective view of a smart phone. It is the perspective view which looked at the front side cabinet from the back side. It is the V section enlarged perspective view of FIG. FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 5. FIG. 7 is an enlarged perspective view of a portion VII in FIG. 4. It is the VIII-VIII line expanded sectional view of FIG. It is a front view which shows the mode of the die-cutting procedure of the housing | casing of a prior art, (a) shows the time of a die-cutting start, (b) shows the time at the time of the 1st and 2nd slide core sliding, (c) is The time when the third slide core slides is shown. (A) is the Xa-Xa line expanded sectional view of Fig.9 (a), (b) is the Xb-Xb line expanded sectional view of Fig.9 (a).

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  2 and 3 show a smartphone 1 as an electronic apparatus according to an embodiment of the present invention. The smartphone 1 includes a display unit 2 as a display display and a display unit 2 having a cover panel 2a and a display panel 2b, for example. The front side cabinet 3 as a housing | casing which covers is provided. The cover panel 2a may be integrated with the touch panel, or may be composed of only a glass panel or an acrylic panel. The display unit 2 may be any of a liquid crystal display, an organic EL display, and a MEMS (Micro Electro Mechanical Systems) display. The back surface of the front cabinet 3 is covered with a rechargeable battery holder 4 having a ground metal plate 4a and a rechargeable battery holder resin portion 4b. The rechargeable battery holder 4 is covered with the rear holder 9 and fixed to the back surface of the front cabinet 3 with screws 40, for example, with the rechargeable battery 6 attached. The back surface of the rechargeable battery holder 4 is covered with a plate-like rear panel 5. A rectangular plate-shaped rechargeable battery 6 is disposed between the rechargeable battery holder 4 and the rear panel 5, and a main substrate 7 is disposed below the rechargeable battery 6. The main board 7 is connected to the upper sub board 8 by a flexible board 7a. The rechargeable battery holder 4, the rechargeable battery 6, the main board 7, the sub board 8, and the like can be configured as a unit as the rechargeable battery holder assembly 10. The squares of the smartphone 1 are covered and protected by a corner protector 3a made of an elastic member such as an elastomer.

  As shown in FIG. 4, the front side cabinet 3 consists of a resin molded product by injection molding. The front-side cabinet 3 has a rectangular plate shape, and in the present embodiment, as shown in FIGS. 6 and 8, the front-side cabinet 3 has a closed cross section in which an internal space 11 that is continuous with left and right side walls extending in the vertical direction of the smartphone 1 is formed. . The closed cross section is formed to have a substantially constant thickness over a wide range above and below the left and right side walls of the housing 3. As shown in FIGS. 5 and 6, the first slide core 53 and the second slide core 53 are positioned at positions corresponding to the tips of the first slide core 53 and the second slide core 54 of the mold 50 to be described later. A communication hole 12 is formed that opens in a direction (vertical direction in the present embodiment) that intersects the direction in which the slide core 54 slides. The cross-sectional shape of the communication hole 12 is not particularly limited, such as a rectangular shape, a triangular shape, a circular shape, or an elliptical shape. The communication hole 12 communicates with the internal space 11 by, for example, a second communication hole 12a having a circular cross section. The shape of the second communication hole 12a is not particularly limited, and may be an elliptical shape, a rectangular shape, a triangular shape, or the like. In any case, the inner dimension is smaller than the inner dimension of the communication hole 12. At least the communication hole 12 is blocked by the adhesive 60. The communication hole 12 may not be a direction perpendicular to the sliding direction, but may be a direction inclined from the vertical direction. As shown in FIG. 7, openings 13 through which the first slide core 53 and the second slide core 54 pass are formed in the squares of the front cabinet 3. The opening 13 is covered with the corner protector 3a described above.

  Next, a method for forming the front cabinet 3 will be described.

  First, in the preparation step, a mold 50 having a fixed mold 51, a movable mold 52, a first slide core 53, a second slide core 54, and another piece 55 as shown in FIG. 1 is prepared. The first slide core 53 and the second slide core 54 are perpendicular to the clamping direction of the fixed mold 51 and the movable mold 52 (the direction of the black arrow in FIG. 4), that is, the vertical direction along the left and right side walls of the front-side cabinet 3. Slide to. The separate piece 55 may be composed of a movable mold 52 or may be composed of a slide core different from the first slide core 53 and the second slide core 54. In the case of a slide core, the separate piece 55 is slidable in the direction intersecting the slide direction of the first slide core 53 and the second slide core 54 (right and left inner side). What is necessary is just to operate | move behind the core 53 and the 2nd slide core 54, and has the insertion part 55a in which the front-end | tip 53a of the 1st slide core 53 and the front-end | tip 54a of the 2nd slide core 54 are inserted. In the present embodiment, the cross-sections of the tips 53a and 54a are circular, but may be oval, rectangular, triangular, or the like.

  Next, in the molding step, the fixed mold 51 and the movable mold 52 are arranged so that the distal ends 53a and 54a of the first slide core 53 and the second slide core 54 are supported by the separate piece 55 as shown in FIG. Clamp the mold. The molten resin is injected into a cavity inside the mold 50 in this state. At this time, even when the first slide core 53 and the second slide core 54 become long, the tips 53a and 54a are supported by the separate piece 55 at the time of injection molding, so the first slide core 53 and the second slide core 54 are supported. Molding defects due to swaying can be avoided. Thereby, the front side cabinet 3 which has the closed cross section in which the internal space 11 extended up and down by the 1st slide core 53 and the 2nd slide core 54 was continuously formed in the periphery (left-right side wall) of the front side cabinet 3 is shape | molded. The The front cabinet 3 is formed in a rectangular plate shape, and a display accommodating portion 3b (shown in FIG. 8) including a flat surface for accommodating the display portion 2 is formed on the front side. In the case of the separate piece 55 constituted by another slide core, the separate piece 55 does not move in a wide range as shown in FIG. Design restrictions such as bosses in the cabinet 3 can be minimized. It is obvious that the communication hole 12 is formed by a separate piece 55, and the second communication hole 12a is formed by the first slide core 53 and the tips 53a and 54a of the second slide core 54. Since the internal space 11 and the communication hole 12 communicate with each other through the second communication hole 12a, there is a problem in terms of waterproofness as it is.

  Then, in the waterproofing process, the adhesive hole 60 is applied from the direction indicated by the arrow in FIG. 6 to close the communication hole 12 in the communication hole 12 that communicates with the internal space 11 formed by the separate piece 55. The adhesive 60 may flow into the second communication hole 12a. Thereby, the space between the pair of internal spaces 11 is blocked, and even if the liquid tries to enter from the opening 13, it does not enter the inside through the communication hole 12.

  And the corner protector 3a is attached to four corners of the front side cabinet 3 so that the opening 13 formed in the front side cabinet 3 by the 1st slide core 53 and the 2nd slide core 54 may be plugged up. At this time, it is desirable to use a material excellent in internal damping such as an elastomer for the corner protector 3a.

  According to this method, the wall thickness is substantially the same and the periphery is configured with a closed cross section and has a high strength, so that the first slide core 53 and the tips 53a and 54a of the second slide core 54 are supported during molding. The front-side cabinet 3 having high strength and waterproofness in which the communication hole 12 formed by the separate piece 55 is closed with the adhesive 60 is obtained.

  In the present embodiment, the inner space 11 is continuously formed by the first slide core 53 and the second slide core 54 at the peripheral edge of the front-side cabinet 3, thereby making the overall thickness as uniform as possible and forming shrinkage. Dents caused by the can be avoided.

  By forming the periphery of the front side cabinet 3 with the resin injected into the cavity formed in the area sandwiched between the outer periphery of the first slide core 53 and the second slide core 54 and the fixed mold 51 and the movable mold 52, A closed cross section having an internal space 11 corresponding to the first slide core 53 and the second slide core 54 is formed. For this reason, by making the overall thickness as uniform as possible, the strength can be increased while preventing sink marks. Thus, since the structure with high rigidity which has a closed cross section can be provided in the right-and-left side wall of the smart phone 1, the mass% of glass fiber only needs about 20% as molten resin to be used. Conventionally, resin materials containing reinforcing fibers such as glass fibers and carbon fibers have been used in portable electronic devices represented by the smartphone 1 in order to achieve both portability and rigidity. Usually, a molten resin whose reinforcing fiber is 40% by mass or more is used at the time of molding, but according to the present invention, about 20% is sufficient. Reinforcing fibers are relatively expensive, but their mass% can be lowered, resulting in cost reduction. In addition, since the number of fibers contained is small, for example, three layers of coating for improving the appearance can be made into two layers, which also reduces the cost.

  In addition, the first slide core 53 and the second slide core 54 are not slid in the left-right direction toward the inside of the housing from the inner side of the front-side cabinet 3, but in the direction along the periphery, Since the second slide core 54 is slid in the vertical direction toward the outside of the housing, it is easy to provide a structure such as a boss inside the front cabinet 3.

  Moreover, the waterproof effect in the front side cabinet 3 is acquired by closing the communication hole 12 by the separate piece 55 used in order to support the front-end | tips 53a and 54a of the 1st slide core 53 and the 2nd slide core 54. FIG. The separate piece 55 only needs to be rigid enough to prevent vibration during molding of the first slide core 53 and the second slide core 54, and thus can be made small (for example, a cross section of 2.1 mm × 2. 5mm rectangle). For this reason, when closing with the adhesive 60, it is also possible to prevent it by, for example, dropping one or several drops of the adhesive 60.

  When the smartphone 1 is assembled, the display unit 2 is attached to the display housing unit 3b. For this reason, it is possible to protect the display unit 2 including a display display that is vulnerable to external shocks, with the peripheral edge of the high-strength front-side cabinet 3 that has a closed cross section.

  Since the corner protector 3a is attached to the four corners of the front side cabinet 3 so as to close the opening 13 formed in the front side cabinet 3 by the first slide core 53 and the second slide core 54, for example, the corner protector 3a is made of an elastomer or the like. By using a material excellent in internal damping, it is possible to obtain the effect of improving the strength against static load and the impact mitigating effect on internal parts due to impact load such as dropping, while closing the opening 13 and improving the appearance.

  Therefore, according to the smartphone 1 according to the present embodiment, the molten resin is injected into the cavity inside the mold 50 with the distal ends 53a and 54a of the first slide core 53 and the second slide core 54 supported by the separate piece 55. Since the front cabinet 3 having a closed cross section in which the inner space 11 is continuously formed by the first slide core 53 and the second slide core 54 is formed at the periphery, the gas assist molding and the inner side are wide. Thus, the strength can be improved and the function can be ensured by forming a closed cross section without relying on molding using a slide core that slides.

(Other embodiments)
The present invention may be configured as follows with respect to the above embodiment.

  That is, in the above embodiment, the internal space 11 is formed in the left and right side walls of the smartphone 1, but the first slide core 53 and the second slide core 54 are provided so as to provide the internal space 11 in the upper and lower side walls. You may make it slide.

  In the above embodiment, the cavity for forming the peripheral edge having the closed cross section of the front side cabinet 3 is formed by the outer periphery of the first slide core 53 and the second slide core 54, the fixed mold 51 and the movable mold 52. However, of course, the slide part which is a part of the fixed mold 51 and the movable mold 52 may be a part for forming the cavity.

  In the above embodiment, the front side cabinet 3 has a rectangular plate shape. However, the casing is not limited to the rectangular plate shape, and the first slide core 53 and the second slide core 54 having a polygonal or semicircular cross section are provided. There is no particular limitation as long as the outer shape has a substantially straight side for sliding movement.

  In the above embodiment, the electronic device is the smartphone 1, but a tablet terminal, PHS (Personal Handy-phone System), PDA (Personal Digital Assistant), personal computer, mobile tool, mobile phone, wearable terminal, electronic dictionary, calculator, It may be a game machine or the like, and may be a small liquid crystal display, a liquid crystal television, a Blu-ray disc recorder, a DVD recorder, or the like.

  In addition, the above embodiment is an essentially preferable illustration, Comprising: It does not intend restrict | limiting the range of this invention, its application thing, or a use. The technical features described in each embodiment can be combined with each other, and a new technical feature can be formed by combining them.

1 Smartphone (electronic equipment)
2 Display section (display display)
2a Cover panel
2b Display panel
3 Front cabinet (housing)
3a Corner protector
3b Display housing
4 Rechargeable battery holder
4a Earth sheet metal
4b Rechargeable battery holder resin part
5 Rear panel
6 Rechargeable battery
7 Main board
7a Flexible substrate
8 Sub-board
9 Rear holder
10 Rechargeable battery holder assembly
11 Internal space
12 communication hole
12a Second communication hole
13 opening
40 screws
50 Mold
51 Fixed type
52 Movable type
53 First slide core
53a Tip
54 Second slide core
54a Tip
55 Another piece
55a plug
60 Adhesive

Claims (5)

In the method of manufacturing an electronic device casing made of a resin molded product,
A movable mold, a fixed mold, a slide core that slides in a direction perpendicular to the mold clamping direction of the movable mold and the fixed mold and along the peripheral edge of the casing, and a slide movement that intersects the slide core. Preparing a mold having a separate piece into which the tip of the slide core is inserted; and
The housing having a closed cross-section in which molten resin is injected into the cavity of the mold while the tip of the slide core is supported by the separate piece, and the inner space is continuously formed by the slide core at the periphery. A method for manufacturing a casing of an electronic device, comprising: a molding step for molding a body. In the manufacturing method of the housing | casing of the electronic device of Claim 1,
A method for manufacturing a casing of an electronic device, further comprising a waterproofing step of applying an adhesive to a communication hole communicating with the internal space formed by the separate piece to close the communication hole. In the manufacturing method of the housing | casing of the electronic device of Claim 1 or 2,
A method of manufacturing a casing of an electronic device, wherein a corner protector is attached to the corner so as to close at least an opening formed in the corner of the casing by the slide core. It has a closed cross-section in which a continuous internal space by a slide core is formed on at least one side of a rectangular plate shape, and intersects the extending direction of the internal space at a position corresponding to the tip of the slide core on the back side of the internal space An electronic device casing characterized in that a communication hole opened in a direction is closed with an adhesive. In the housing | casing of the electronic device of Claim 4,
The case of the electronic device, wherein the communication hole communicates with the internal space through a second communication hole having an inner dimension smaller than the inner dimension of the communication hole.