Electronic device

Abstract

To provide a technology capable of achieving weight reduction.SOLUTION: An electronic apparatus includes a case body 102 that accommodates a circuit board 112 therein, an outer lid 104 closing an opening leading to the inside of the case body 102, an inner lid 110 that is fitted and arranged inside the case body 102 and partitions the inside of the case body 102 from the opening to an accommodation portion of the circuit board 112, and a sealing material that seals at least a fitting region of the inner lid 110 on the inner surface of the case body 102.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an electronic device in which electronic components are housed inside a case body.

Background Art

[0002] As prior art related to this type of electronic device, a power plug having a waterproof function is known (see, for example, Patent Document 1). This power plug has a function of preventing liquid from entering inside by installing an inner lid capable of covering internal elements inside the power plug body and filling a colloid between the inner lid and the plate, and has a waterproof rating reaching IPX7.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, although the prior art power plug can reduce the weight required for the waterproof function, ultimately, it has a waterproof function by filling a colloid in the space between the inner lid and the plate, and still the filling amount is of a size corresponding to the volume of the space. Also, as the power plug becomes larger, the filling amount of the colloid increases three-dimensionally (cubically) with the expansion of the internal space, and the corresponding weight increases, so the fundamental problem has not been solved.

[0005] Therefore, the present invention provides a technology capable of achieving weight reduction.

Means for Solving the Problems

[0006] The present invention provides an electronic device. In the electronic device of the present invention, electronic components are housed inside a case body, and an opening communicating with the inside of the case body is closed by an outer lid. The waterproof structure in the present invention is realized by an inner lid and a sealing material. That is, the inner lid is fitted and arranged inside the case body, thereby partitioning the inside of the case body between the opening and the housing portion of the electronic components. And the sealing material seals at least the fitting region (fitting surface) of the inner lid on the inner surface of the case body.

[0007] In the waterproof structure of the present invention, the "inner lid" may seem to be similar to the existing technology in the sense of "partitioning the inside of the case body", but actually it is significantly different in meaning. That is, the "inner lid" forms a "fitting region" where the "sealing material" can seal by fitting inside the case body as described above. Since the "fitting region" is a region where the inner surface of the case body and the inner lid are in a fitting relationship, it becomes a two-dimensional (planar) region on the inner surface of the case body. And the "sealing material" reliably waterproofs the inside of the case body partitioned by the "inner lid" and further the electronic components housed inside by sealing only such a two-dimensional (planar) "joint region".

[0008] Therefore, according to the present invention, the amount of the "sealing material" used is extremely small (the minimum necessary), and the weight reduction of the waterproof structure can be achieved. Also, since the "sealing material" seals a two-dimensional (planar) "fitting region" (for example, it becomes a thin film-like seal), even if the size of the electronic components or the electronic device increases and accordingly the volume of the "case body" increases three-dimensionally (cubically), the "fitting region" only increases two-dimensionally (squarely) or one-dimensionally, and the amount of the "sealing material" used does not increase inadvertently. Therefore, compared with the "waterproof structure filled in the space", the rate of increase in weight with respect to the increase in the volume of the case body can be extremely low, and weight reduction can be achieved as a whole.

[0009] Preferably, the sealing material may further seal the corner portion formed by the facing surface of the case body and the inner lid. In this case, the corner portion is preferably on the opening side of the case body. Thereby, the sealing performance by the sealing material is further improved, and a more reliable and highly durable waterproof structure can be realized. Also, even in this case, since the sealing material is not filled in the "space from the inner lid to the opening of the case body", weight reduction can be maintained.

[0010] Further, the case body preferably has a shape (taper shape) in which the width of the opening is larger than the width of the inner lid and the width of the inner surface narrows from the opening toward the fitting region. In this case, the fitting between the inner lid and the case body becomes an interference fit, and accidental displacement of the inner lid inside the case body is prevented. Also, even in the manufacturing process, the inner lid can be easily inserted into the case body from the opening and fitted at the interference fit position, and the assembly can be easily completed. Also, the fitting between the inner lid and the case body becomes stronger, and the sealing effect by the sealing material can be further improved.

Advantages of the Invention

[0011] According to the present invention, weight reduction can be achieved.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, an AC adapter is taken as an example of an electronic device, but the present invention is not limited thereto.

[0014] 〔AC Adapter〕 FIG. 1 is a perspective view showing the configuration of an AC adapter 100 which is an embodiment of an electronic device. The AC adapter 100 of the present embodiment is a power supply component that converts an AC power supply (for example, AC + 100V) into a DC power supply (for example, DC + 19V). Also, in FIG. 1(A) and FIG. 1(B), the posture of the AC adapter 100 is shown with the top and bottom reversed.

[0015] 〔Case Body〕 The AC adapter 100 includes a case body 102, and electronic components (such as a circuit board) not shown are housed inside the case body 102. The case body 102 is basically in a vertical prism shape in the standing posture shown in FIG. 1, and the four corners of its outer peripheral wall 102a are formed into an arc surface shape (R shape).

[0016] 〔Outer Cover〕 In addition, the AC adapter 100 includes an outer cover 104 in addition to the case body 102, and the case body 102 and the outer cover 104 form an overall vertically long shape. The case body 102 has an opening at the upper end in the standing posture shown in FIG. 1(A), and the outer cover 104 is joined to this opening to close the opening leading to the inside of the case body 102. The outer cover 104 also has an oval shape that matches the outer shape of the case body 102.

[0017] 〔Bush Member〕 A bush member 106 is joined to a case body 102 of an AC adapter 100, and the bush member 106 wraps and protects a wiring 106a extending from the AC adapter 100. The case body 102 and an outer lid 104 are formed with extraction parts 102c and 104a of the bush member 106. In a state where the opening of the case body 102 is closed by the outer lid 104, the extraction parts 102c and 104a are integrally formed in a nozzle shape and surround the bush member 106 from the outside. Also, the wiring 106a is connected to an electronic component inside the case body 102.

[0018] The AC adapter 100 has a pair of plugs 108, and these plugs 108 project and extend from a bottom wall 102b of the case body 102. Also, the plugs 108 are connected to a circuit board (not shown) inside the case body 102.

[0019] FIG. 2 and FIG. 3 are exploded perspective views showing the internal configuration of the AC adapter 100. In these FIGS. 2 and 3, the direction in which the wiring 106a extends from the AC adapter 100 is shown with a 180° inversion.

[0020] 〔Electronic Component〕 As described above, the AC adapter 100 includes an electronic component housed inside the case body 102. Here, as an example of the electronic component, a circuit board 112 is cited. For this reason, guide ribs 102e are formed to extend in the longitudinal direction (vertical direction) inside the case body 102, and the circuit board 112 is inserted inside the case body 102 while being guided by the guide ribs 102e in the manufacturing process. Also, an electronic circuit (AC-DC conversion circuit) (not shown) is formed on the circuit board 112, and when the circuit board 112 is inserted inside the case body 102, it is electrically connected to the plugs 108 via crimp terminals (mounted on the circuit board 112) (not shown).

[0021] The case body 102 has an opening at one end in the longitudinal direction (vertical direction), and this opening communicates with the inside of the case body 102. In the disassembled state shown in FIGS. 2 and 3, the inside of the case body 102 is open through the opening. A groove portion 102f is formed at the opening edge of the case body 102, and a fitting rib 104b is formed at the peripheral edge of the outer lid 104 corresponding thereto. When the case body 102 and the outer lid 104 are assembled, the groove portion 102f and the fitting rib 104b are fitted together and positioned relative to each other. Note that the outer lid 104 and the case body 102 are joined by adhesion, welding, or the like.

[0022] [Inner lid] The AC adapter 100 includes an inner lid 110, and this inner lid 110 is fitted and disposed inside the case body 102. The inner lid 110 is generally a plate-shaped member, but the rectangular central portion 110a is formed in a stepped shape that is raised one step higher than its peripheral portion 110b. Also, the periphery of the inner lid 110 has an oval shape that matches the outer shape of the case body 102 and the outer lid 104, and a notch portion 110c is formed in a U shape toward the central portion 110a at one end in the longitudinal direction of the peripheral portion 110b.

[0023] The bush member 106 is bent in an elbow shape inside the case body 102, and an engaging portion 106b in the form of a concave groove extending in a U shape along the outer peripheral surface is formed at the bent end portion. The engaging portion 106b is located at a position that exactly matches the notch portion 110c of the inner lid 110. When the bush member 106 is assembled, the peripheral portion 110b along the notch portion 110c fits (is inserted) into the concave groove of the engaging portion 106b, thereby engaging with the inner lid 110.

[0024] The middle cover 110 is assembled to the case body 102 by fitting (engagement) between the outer peripheral surface of the middle cover 110 and the inner wall surface of the case body 102. The inner wall surface 102d of the case body 102 has a tapered shape in which the inner dimension narrows from the opening toward the inside (downward in FIGS. 2 and 3). At a position near the opening of the case body 102, there is sufficient clearance over the entire circumference between the outer peripheral surface of the middle cover 110 and the inner wall surface 102d. However, at a position further inside from the opening, the outer peripheral surface (outer peripheral edge) of the middle cover 110 is in a fitting state with the inner wall surface 102d of the case body 102 over substantially the entire circumference. In this state, the middle cover 110 partitions the inside of the case body 102 between the opening of the case body 102 and the accommodation portion of the circuit board 112. Hereinafter, this point will be described in more detail.

[0025] 〔Partition by the middle cover〕 FIG. 4 is a cross-sectional view (longitudinal cross-sectional view along the longitudinal direction) showing the internal structure of the AC adapter 100. Among them, FIG. 4(A) shows a longitudinal cross-section of the AC adapter 100 including the outer cover 104, and FIG. 4(B) shows a longitudinal cross-section excluding the outer cover 104. Note that FIG. 4 shows the state in which the above-described crimp terminal 112a is joined to the plug 108.

[0026] As described above, the circuit board 112 (not shown because it is on the front side of the cross-section in FIG. 4) is accommodated inside the case body 102. However, the middle cover 110 partitions the inside of the case body 102 into two chambers, namely, the accommodation portion of the circuit board 112 (below the middle cover 110 in FIG. 4) and the space from the opening to the middle cover 110. Inside the case body 102, the accommodation portion of the circuit board 112 occupies most of the space volume, and the space volume from the middle cover 110 to the opening is considerably smaller compared to the accommodation portion.

[0027] Even in the partitioned state by the middle cover 110, as described above, since the bush member 106 communicates with the accommodation portion of the circuit board 112 through the notch portion 110c, the wiring 106a extending from the outside of the AC adapter 100 is drawn into the accommodation portion and is connected to the circuit board 112 inside the case body 102 (the connection state is not shown).

[0028] 〔Fitting region〕 FIG. 5 is a plan view and a longitudinal sectional view of the AC adapter 100 excluding the outer lid 104. Further, FIG. 6 is a longitudinal sectional view of the AC adapter 100 excluding the outer lid 104. Among these, (A) in FIG. 5 is a plan view, and (B) in FIG. 5 is a sectional view taken along B-B in the plan view. (A) in FIG. 6 is a longitudinal sectional view taken along the line VI-A-VI-A in the plan view, and (B) in FIG. 6 is a longitudinal sectional view taken along the line VI-B-VI-B in the plan view.

[0029] In FIG. 5(A): As described above, the middle lid 110 is fitted and disposed inside the case body 102. In the fitted state, except for the notch portion 110c, the outer peripheral surface of the middle lid 110 is generally in contact with the inner wall surface 102d of the case body 102 over the entire circumference (there is a slight gap), and a fitting region (a fitting surface, a range where the outer peripheral surface of the middle lid 110 and the inner wall surface 102d of the case body 102 are butted against each other) is formed between the two.

[0030] In FIG. 5(B): At this time, at the position of the upper end opening of the case body 102, the opening width D1 in the longitudinal direction is slightly larger than the outer dimension D2 in the longitudinal direction of the middle lid 110. Further, the inner wall surface 102d of the case body 102 has a tapered shape in which the inner dimension in the longitudinal direction gradually narrows from the opening position toward the inner depth (accommodation space). For this reason, at a position a certain distance inside from the opening, the inner dimension in the longitudinal direction of the inner wall surface 102d becomes equal to the outer dimension D2 in the longitudinal direction of the middle lid 110.

[0031] In FIG. 6(A): Also, at the position of the upper end opening of the case body 102, the opening width E1 in the short direction is slightly larger than the outer dimension E2 in the short direction of the middle lid 110. Here too, the inner wall surface 102d of the case body 102 has a tapered shape in which the inner dimension in the short direction gradually narrows from the opening position toward the inner depth (accommodation space). For this reason, at a position a certain distance inside from the opening, the inner dimension in the short direction of the inner wall surface 102d becomes equal to the outer dimension E2 in the short direction of the middle lid 110.

[0032] 〔Positioning of the Middle Lid〕 Due to the tapered shape of the inner wall surface 102d of the case body 102 as described above, the middle cover 110 is positioned and arranged by fitting (interference fit) inside the case body 102. Also, the bush member 106 is supported and positioned at the extraction part 102c of the case body 102. The middle cover 110 is positioned inside the case body 102 via the bush member 106 when the engaging part 106b of the bush member 106 engages (is inserted) with the notch part 110c.

[0033] 〔Sealing Material〕 As shown in (B) of FIG. 5 and (A) and (B) of FIG. 6, in this embodiment, a sealing material 120 is applied on the middle cover 110, and the sealing material 120 forms a layer on the peripheral part 110b of the central part 110a. The sealing material 120 is, for example, a resin filler such as PP. When applied on the middle cover 110, it seals the fitting region (fitting surface) between the middle cover 110 and the inner surface of the case body 102. Thereby, the function of waterproofing the inside of the case body 102, particularly the accommodation part of the circuit board 112, is ensured. This will be further explained below.

[0034] FIG. 7 is an enlarged cross-sectional view of the surrounded part indicated by the dashed-dotted line in (B) of FIG. 6. Among them, (A) in FIG. 7 shows a cross-section centered on the fitting region between the middle cover 110 and the inner wall surface 102d of the case body 102, and (B) in FIG. 7 shows a cross-section centered on the engaging part between the notch part 110c of the middle cover 110 and the engaging part 106b and the contact region between the bush member 106 and the inner wall surface 102d of the case body 102.

[0035] 〔Corner Sealing Layer〕 FIG. 7(A): Here, as shown colored in gray, the sealing material 120 is fixed (cured, solidified) as a sealing layer 120a having a certain thickness on the peripheral part 110b in the state of being applied on the middle cover 110. Here, it is shown that the sealing layer 120a is formed over the entire area of the peripheral part 110b, but the sealing layer 120a only needs to be formed so as to seal at least the corners between the peripheral part 110b and the inner wall surface 102d over the entire circumference.

[0036] [Fitting Region Seal Layer] In Fig. 7(A): Further, the sealing material 120 is fixed (cured, solidified) in a thin film shape within a slight gap existing between the middle lid 110 and the inner wall surface 102d of the case body 102, and this forms the fitting region seal layer 120b. This is because the sealing material 120 has high fluidity (for example, a viscosity of about 200 mPa·s) before its curing (during the coating process) and can penetrate into the slight gap existing between the middle lid 110 and the inner wall surface 102d of the case body 102.

[0037] Also, since there are certain tolerances in the finished dimensions of the case body 102 and the middle lid 110, which are resin molded members, during molding, it is practically difficult to consider that the gap between the inner wall surface 102d and the outer peripheral surface of the middle lid 110 completely disappears in the actual fitting state. From this, the inventor of the present invention noticed that if a small amount of the sealing material 120 is applied onto the middle lid 110 during the manufacturing process, the sealing material 120 flows into the fitting region (within the gap) between the outer peripheral surface of the middle lid 110 and the inner wall surface 102d of the case body 102, and a reliable waterproof seal is achieved by forming the thin film fitting region seal layer 120b, thus conceiving the waterproof structure of the present embodiment.

[0038] In Fig. 7(B): The waterproof seal by forming the thin film of the sealing material 120 as described above can also be applied to the fitting region between the middle lid 110 and the bush member 106, and the contact region between the bush member 106 and the inner wall surface 102d of the case body 102. That is, if a small amount of the sealing material 120 is applied onto the middle lid 110 during the manufacturing process, the sealing material 120 also flows into the space between the notch portion 110c of the middle lid 110 and the engaging portion 106b of the bush member 106, and the same thin film fitting region seal layer 120b is formed. Also, at a position where there is a certain space between the inner side of the bent portion of the bush member 106 and the case body 102, a seal layer 120c similar to that on the peripheral edge portion 110b is formed. However, in the contact region between the bush member 106 below this and the inner wall surface 102d of the case body 102, the sealing material 120 flows into these gaps, and a thin film contact region seal layer 120d is also formed.

[0039] Note that the sealing material 120 was originally filled around the circuit board 112 and has no erosiveness (aggressiveness) to the electronic circuit, so it may flow down from the fitting region or the bonding region to the accommodating portion of the circuit board 112 as shown in the figure.

[0040] Thus, according to the present embodiment, in addition to the accommodating portion of the circuit board 112 being partitioned by the middle cover 110 up to the opening inside the case body 102, the fitting region (fitting surface) between the middle cover 110 and the inner wall surface 102d of the case body 102 is sealed with the sealing material 120, so that a reliable waterproof function for the accommodating portion can be achieved. Note that the waterproofing around the plug 108 on the bottom wall 102b of the case body 102 is well-known and is omitted here.

[0041] 〔Assembly Order〕 FIG. 8 is a diagram showing the assembly order of the AC adapter 100. The assembly order of the above AC adapter 100 will be described.

[0042] In FIGS. 8(A)(B): Insert the engaging portion 106b of the bush member 106 into the notch 110c of the middle cover 110 (alternatively, insert the notch 110c of the middle cover 110 into the engaging portion 106b of the bush member 106). Although not shown here, the wiring 106a and the circuit board 112 are soldered.

[0043] In FIGS. 8(C): Accommodate the circuit board 112 inside the case body 102, and after joining the plug 108 and the crimp terminal 112a as described above, assemble the middle cover 110 and the bush member 106 to the case body 102. At this time, by hooking the bush member 106 on the take-out portion 102c, the middle cover 110 is positioned inside the case body 102 via the bush member 106. Also, the middle cover 110 is similarly positioned by fitting with the inner wall surface 102d of the case body 102 as described above.

[0044] At this time, since the inner wall surface 102d of the case body 102 has the tapered shape as described above, the middle lid 110 does not sink in the depth direction (downward in FIG. 8) from the fitting position. Further, since the middle lid 110 is also supported by the bush member 106, the sinking of the middle lid 110 is further suppressed.

[0045] And in this state, the sealing material 120 is applied onto the middle lid 110. At this time, if the sealing material 120 is simply applied (roughly filled) along the periphery of the central portion 110a, there is no need to pay particular careful attention, and the workability is extremely good. If the sealing material 120 is roughly filled, the sealing material 120 spreads everywhere by its own fluidity, and also flows into and penetrates the gaps everywhere, and various seal layers 120a, 120b, 120c, 120d, etc. as described above can be formed.

[0046] In FIG. 8 (D): Then, when the outer lid 104 is placed on the opening of the case body 102 and joined (adhered, welded), the assembly of the AC adapter 100 is completed.

[0047] According to the above-described embodiment, the following usefulness can be obtained. (1) By arranging the middle lid 110 inside the case body 102 and simply applying a small amount of the sealing material 120 onto the middle lid 110, a reliable waterproof structure can be realized. For this reason, the usage amount of the sealing material 120 can be significantly reduced, and the manufacturing cost can be reduced and the AC adapter 100 can be lightened.

[0048] (2) Even if the size of the AC adapter 100 increases, since it is a structure in which the inside of the case body 102 is partitioned by the middle cover 110 and the fitting region is sealed in the same manner, the increase rate of the amount of the sealing material 120 used due to the increase in size can be kept low. That is, although the increase in size will three-dimensionally (cubically) increase the space volume inside the case body 102, the sealing material 120 does not need to be filled in the space, but only needs to seal the fitting region. And since the fitting region only increases two-dimensionally (squared) even if the size of the case body 102 or the like increases, the amount of the sealing material 120 used to form the fitting region sealing layer 120b can be kept small, and further weight reduction can be achieved. Also, if the thickness of the middle cover 110 is constant when the size of the case body 102 increases, the width of the fitting region will also be constant. Therefore, the area of the fitting region will increase only by the amount by which the inner peripheral length of the case body 102 extends, and it only increases one-dimensionally. Thus, the amount of the sealing material 120 used can be further reduced.

[0049] (3) In the manufacturing process, the sealing material 120 only needs to be roughly applied (filled) on the middle cover 110, so no particularly delicate work is required, and the working efficiency can be improved. Also, since the amount of the sealing material 120 used is small, the working time can be shortened accordingly, which also contributes to the improvement of the production efficiency of the AC adapter 100.

[0050] (4) The middle cover 110 is inserted into and positioned inside the case body 102 in a state combined (engaged) with the bush member 106, and is also positioned by the tapered shape of the inner wall surface 102d of the case body 102. Therefore, it is not necessary to pay particular attention to the positioning of the middle cover 110 in the manufacturing process, and the working efficiency can be further improved. Also, there is no need to form a part such as a rib on the inner wall surface 102d of the case body 102 to support the middle cover 110, which also leads to a reduction in the amount of the molding resin material used.

[0051] The present invention can be implemented in various modified forms without being restricted to the above-described embodiment. As described above, the electronic device is not limited to the AC adapter 100, and the present invention can be implemented as various electronic devices using a waterproof structure.

[0052] The case body 102 does not have to have the substantially prismatic outer shape exemplified in one embodiment, and may have other outer shapes. Also, the inner lid 110 may have a shape other than the one exemplified in one embodiment.

[0053] The electronic components are not limited to those such as the circuit board 112, and electronic components such as a battery, an electric fan, and a speaker may be accommodated.

[0054] In one embodiment, the bush member 106 is attached to one end side in the longitudinal direction of the case body 102, but it may be attached to a position closer to the center in the longitudinal direction. In this case, the bush member 106 may be disposed so as to penetrate the outer surface of the outer lid 104 or the central portion 110a of the inner lid 110. Also, a latching member such as a latching claw may be formed on the bush member 106 that penetrates the inner lid 110 so that it can engage with the inner lid 110 even when it has penetrated the inner lid 110.

[0055] In addition, the various shapes, sizes, etc. given together with the drawings are merely preferred examples, and it goes without saying that the present invention can be implemented by appropriately changing these.

Description of Reference Numerals

[0056] 100 AC adapter 102 Case body 104 Outer lid 106 Bush member 108 Plug 110 Inner lid 120 Sealing material

Claims

1. A case body for housing electronic components therein, An outer lid for closing an opening communicating with the inside of the case body, An inner lid that is fitted and disposed inside the case body and partitions the inside of the case body between the opening and the housing portion of the electronic components, And a sealing material for sealing a fitting region formed in at least a gap between the outer peripheral surface of the inner lid and the inner surface of the case body among the inner surfaces of the case body. The case body, The electronic device is characterized in that the width of the opening is larger than the width of the inner lid, and the width of the inner surface narrows from the opening toward the fitting region.

2. In the electronic device according to claim 1, The sealing material, The electronic device is characterized in that it further seals a corner portion formed by the inner surface of the case body and the inner lid.

3. In the electronic device according to claim 1 or 2, A bush member joined to the case body and surrounding a wiring connected to the electronic components from the outside of the case body between the outer lid and the case body, A notch formed in the inner lid for conducting the bush member to the housing portion inside the case body together with the wiring, An engaging portion formed in the bush member, engaging with the inner lid in a conducting state with respect to the notch, and positioning the inner lid inside the case body And further comprises an electronic device.

4. In the electronic device according to claim 3, The sealing material, The electronic device is characterized in that it further seals an engaging region between the notch and the engaging portion.

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