Waterproof structure for electronic apparatus

Abstract

To provide a waterproof structure in which a lid body can be easily attached / detached and which is capable of stably presenting a desired waterproof performance.SOLUTION: A waterproof structure for an electronic apparatus 10 having an electronic circuit storage space comprises a housing 20 including a first opening 24, a lid body 40 mounted into the first opening 24 in a freely removable manner by a snap fit system, and a porous body 50 which is provided within the housing 20. The housing 20 includes a partition wall 25 separating a space within the housing 20 into the electronic circuit storage space and a residual space, and the partition wall 25 includes a second opening 26. The lid body 40 waterproofs the electronic circuit storage space by perfectly closing the second opening 26 when it is mounted in the first opening 24. The partition wall 25 further includes a third opening 28, and the porous body 50 is disposed so as to close the third opening 28. Air in the electronic circuit storage space can be exhausted through the third opening 28 and the porous body 50 to the residual space.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a waterproof structure for electronic devices, and particularly to a waterproof structure for portable electronic devices driven by a battery.

Background Art

[0002] In recent years, many portable electronic devices are designed to have waterproof performance according to the usage environment. The waterproof performance is often indicated by an IP code. For example, IPX7 (Grade 7) indicates that it has waterproof performance capable of withstanding submersion in water at a depth of 1 m for 30 minutes.

[0003] Fig. 9 shows a conventional electronic device 100 having waterproof performance. The electronic device 100 includes a housing 110 that houses a battery and the like, and a lid 120 that is attached to an opening 114 for battery replacement provided on the back side of the housing 110. The lid 120 is attached to the housing 110 by inserting claw portions 121, 121 into recesses 111, 111 and then engaging (snap-fitting) engaging portions 122, 122 with recesses 112, 112 while elastically deforming them. At this time, a packing portion 123 provided on the lid 120 is embedded in a groove portion 113 of the housing 110, thereby preventing water from entering the housing 110.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In a waterproof structure such as the above-described electronic device 100, the pressure inside the housing may increase when the lid is attached. If the pressure inside the housing becomes excessively high, the lid may bulge, or the snap fit may be released and the lid may unintentionally come off.

[0006] Unintentional removal of the lid can be prevented by fastening the lid to the housing with screws rather than snap-fitting. However, this type of waterproof structure makes attaching and removing the lid cumbersome, requiring the use of tools. Furthermore, this type of waterproof structure can cause problems, such as insufficient screw tightening resulting in insufficient adhesion between the packing and the groove, making it impossible to achieve the desired waterproof performance.

[0007] The present invention has been made in consideration of the above circumstances, and its object is to provide a waterproof structure that allows the lid to be easily attached and detached and that can stably exhibit the desired waterproof performance, and an electronic device equipped with such a waterproof structure. [Means for solving the problem]

[0008] In order to solve the above problems, the waterproof structure of the present invention is a waterproof structure for an electronic device having an electronic circuit accommodating space therein, and comprises a housing having a first opening, a lid body removably attached to the first opening using a snap-fit method, and a porous body provided inside the housing, wherein the housing has a partition wall that divides the space within the housing into an electronic circuit accommodating space and a remaining space, the partition wall has a second opening, and the lid body is configured to partially block the first opening and completely block the second opening when attached to the first opening, thereby waterproofing the electronic circuit accommodating space, the partition wall further has a third opening, and the porous body is arranged to block the third opening, so that air within the electronic circuit accommodating space can be discharged through the third opening and the porous body to the remaining space.

[0009] The waterproof structure may further include an annular gasket provided on the lid body, the partition having a wall portion surrounding the second opening, and when the lid body is attached to the first opening, the gasket may be configured to adhere to the wall portion.

[0010] In this case, it is preferable that the packing has an uneven surface facing the wall portion, and that this uneven surface be configured to come into close contact with the wall portion when the lid body is attached to the first opening.

[0011] The waterproof housing may further have a fourth opening that connects the remaining space to the outside of the housing.

[0012] The waterproof porous body preferably has a Gurley number of 15 seconds or less.

[0013] In addition, in order to solve the above-mentioned problems, the electronic device of the present invention is an electronic device having an electronic circuit accommodating space therein, and comprises a housing having a first opening, a lid body removably attached to the first opening using a snap-fit method, a porous body provided inside the housing, and an electronic circuit board and a battery accommodated in the electronic circuit accommodating space, wherein the housing has a partition wall dividing the space within the housing into an electronic circuit accommodating space and a remaining space, the partition wall having a second opening, and the lid body configured to partially block the first opening and completely block the second opening when attached to the first opening to waterproof the electronic circuit accommodating space, the partition wall further having a third opening, and the porous body being arranged to block the third opening, so that air within the electronic circuit accommodating space can be discharged through the third opening and the porous body to the remaining space. Effect of the Invention

[0014] According to the present invention, it is possible to provide a waterproof structure in which the lid can be easily attached and detached and which can stably exhibit the desired waterproof performance, and an electronic device equipped with such a waterproof structure. [Brief description of the drawings]

[0015] [Figure 1] 1A and 1B are diagrams showing the appearance of an electronic device according to an embodiment of the present invention, in which (A) is a perspective view seen from the front side, and (B) is a perspective view seen from the rear side. [Diagram 2] 1 is an exploded perspective view of an electronic device according to an embodiment of the present invention. [Diagram 3] 1A and 1B are diagrams showing the housing of an electronic device according to an embodiment of the present invention, in which (A) is a plan view seen from the rear side, (B) is a schematic cross-sectional view taken along line α-α in (A), and (C) is a schematic cross-sectional view taken along line β-β in (A). [Figure 4] It is a diagram showing a lid of an electronic device according to an embodiment of the present invention, where (A) is a rear view and (B) is a schematic cross-sectional view taken along line γ-γ in (A). [Figure 5] It is a schematic cross-sectional view of an electronic device according to an embodiment of the present invention in a state where a lid is about to be attached. [Figure 6] It is a schematic cross-sectional view of an electronic device according to an embodiment of the present invention in a state where a lid is attached. [Figure 7] It is another schematic cross-sectional view of an electronic device according to an embodiment of the present invention in a state where a lid is attached. [Figure 8] It is a diagram showing a part of a second packing used in an electronic device according to the present invention, where (A) is a perspective view of the second packing in an embodiment, (B) is a perspective view of the second packing in a modified example, and (C) is a perspective view of the second packing in another modified example. [Figure 9] It is an exploded perspective view of a conventional electronic device.

Mode for Carrying Out the Invention

[0016] Hereinafter, embodiments of an electronic device and a waterproof structure according to the present invention will be described with reference to the accompanying drawings.

[0017] [Embodiment] FIG. 1 shows an electronic device 10 according to an embodiment of the present invention. The electronic device 10 according to this embodiment is a device for wirelessly transmitting a call signal to a receiver at a remote location, and includes a housing 20 and a lid 40 attached to the back side of the housing 20. An interface portion 11 is provided on the front side of the housing 20. The electronic device 10 is driven by a battery.

[0018] The interface portion 11 has the function of a call button operated by a user. When the user presses the interface portion 11, the electronic circuit housed in the housing 20 operates and a call signal is transmitted.

[0019] The interface unit 11 also has the function of notifying the user of low battery power by blinking. When the electronic circuit housed in the housing 20 detects a low battery power (i.e., when the battery output voltage falls below a predetermined threshold), the electronic circuit controls the interface unit 11, causing the interface unit 11 to change from off to blinking.

[0020] 2, the lid 40 has a claw portion 41 provided at one end in the longitudinal direction and an elastically deformable snap-fit portion 42 provided at the other end in the longitudinal direction, and is detachably attached to the housing 20 by a snap-fit method. More specifically, the lid 40 is attached to the housing 20 by inserting the claw portion 41 into a recess 29 of the housing 20, which will be described later, and then elastically deforming the snap-fit portion 42 to engage with a fourth opening 30 of the housing 20, which will be described later (see FIGS. 5 and 6).

[0021] 3 shows the housing 20. (A) is a plan view seen from the rear side, (B) is a schematic cross-sectional view taken along line α-α in (A), and (C) is a schematic cross-sectional view taken along line β-β in (A). Note that (A) shows an electronic circuit board housed in the housing 20, but (B) and (C) do not show the electronic circuit board.

[0022] The housing 20 is made up of a front housing 21 and a rear housing 22 that are joined together with screws 31, 31, 32, and a first gasket 23 made of silicone rubber. The first gasket 23 is designed to prevent water from entering the housing 20 through a small gap that is created when the front housing 21 and the rear housing 22 are joined together. The first gasket 23 also blocks air.

[0023] The rear housing 22 has a first opening 24 having a shape corresponding to the lid 40, a recess 29 for receiving the tab 41 of the lid 40, a fourth opening 30 for engaging with the snap-fit portion 42 of the lid 40, and a partition wall 25 that separates the space within the housing 20 into a front space for accommodating an electronic circuit board (this corresponds to the "electronic circuit accommodating space" of the present invention) and a rear space in which the recess 29 and the fourth opening 30 are located (this corresponds to the "remaining space" of the present invention). The partition wall 25 has a second opening 26 and a third opening 28. The front space and the rear space are connected by the second opening 26 and the third opening 28. Note that in FIG. 3(A), the partition wall 25 is represented by hatching.

[0024] The partition wall 25 further has a continuous wall portion 27 that surrounds the second opening 26. As can be seen from FIG. 3(A), the wall portion 27 is located outside the second opening 26 and inside the first opening 24.

[0025] The electronic device 10 according to this embodiment further includes a film-like porous body 50. As shown in Figures 3(A) and 3(C), the porous body 50 is disposed in the rear space so as to close the third opening 28.

[0026] In this example, a fluororesin porous film (model number: S-NTF2026A-N06J) manufactured by Nitto Denko Corporation was used as the porous body 50. This porous film has a thickness of 0.1 mm, a Gurley number indicating the ease of air permeability of 10 seconds, and a water resistance indicating the difficulty of water permeability of 200 kPa. In other words, the porous body 50 has the property of allowing air to pass through easily but preventing water from passing through under an IPX7 test environment.

[0027] 4 shows the lid 40 and the annular second packing 43 provided on the lid 40. (A) is a rear view, and (B) is a schematic cross-sectional view taken along line γ-γ in (A). The lid 40 has a shape corresponding to the first opening 24 of the housing 20, and has the claw portion 41 and the snap-fit portion 42 as described above.

[0028] The second gasket 43 is made of silicone rubber. As shown in FIGS. 4(B) and 8(A), the second gasket 43 has two flat surfaces (first surface 43a and second surface 43b) that contact the lid 40, and a third surface 43c that comes into close contact with the wall 27 of the housing 20 when the lid 40 is attached to the housing 20. The third surface 43c has irregularities (more precisely, two protrusions formed at a distance), and therefore can be called an irregular surface. The irregular surface 43c can also be said to be the surface that faces the wall 27.

[0029] As described above, the cover 40 is attached to the housing 20 by inserting the tabs 41 into the recesses 29 of the housing 20 and then engaging the snap-fit portions 42 with the fourth opening 30 of the housing 20 while elastically deforming them (see FIGS. 5 and 6). At this time, the uneven surface 43c of the second packing 43 provided on the cover 40 rubs against the wall portion 27, causing the uneven surface 43c to be slightly elastically deformed (squashed), so that the second packing 43 and the wall portion 27 come into close contact with each other.

[0030] When the second gasket 43 and the wall portion 27 come into close contact, the second opening 26 is completely closed. Here, "completely" closed refers to a state in which water and air do not substantially enter or exit. On the other hand, there is no gasket that fills the gap between the cover 40 and the housing 20 (rear-side housing 22) at the first opening 24. In other words, the first opening 24 is "incompletely" closed. Therefore, even after the cover 40 is attached to the housing 20, the rear-side space within the housing 20, which is located on the rear side of the partition wall 25, remains in communication with the outside of the housing 20 via the first opening 24. The rear-side space also remains in communication with the outside of the housing 20 via the fourth opening 30.

[0031] As shown in FIG. 7, the partition wall 25 has a third opening 28 closed by a porous body 50. And as described above, the porous body 50 has the property of allowing air to pass through. Therefore, when the pressure in the space inside the housing 20 (the front-side space located on the front side of the partition wall 25) increases due to the attachment of the lid body 40 to the housing 20, the air in the front-side space is discharged to the back-side space and outside the housing 20 through the third opening 28 and the porous body 50. As a result, the increase in the pressure in the space inside the housing 20 is alleviated. And thereby, the engagement between the snap-fit portion 42 of the lid body 40 and the fourth opening 30 is released, preventing the lid body 40 from accidentally coming off.

[0032] As described above, the porous body 50 has the property of not allowing water to pass through. Therefore, even if water enters the gap between the lid body 40 and the housing 20 (the back-side housing 22) at the first opening 24 and the back-side space from the fourth opening 30, the water does not move to the front-side space for accommodating the electronic circuit board through the porous body 50 and the third opening 28.

[0033] In addition, the porous body 50 and the third opening 28 also have a function of preventing the front-side space for accommodating the electronic circuit board from becoming negative pressure by introducing air into the front-side space when the front-side space is about to become negative pressure. When the front-side space becomes negative pressure, it becomes difficult to remove the lid body 40.

[0034] As described above, the embodiments of the electronic device and the waterproof structure according to the present invention have been described, but the configuration of the present invention is not limited thereto.

[0035] For example, the electronic device according to the present invention is not limited to a device that wirelessly transmits a call signal. Also, the electronic device according to the present invention is not limited to a device driven by a battery.

[0036] Also, the Gurley seconds of the porous body are not limited to 10 seconds, and may be, for example, 15 seconds. Even with such a porous body, it is possible to sufficiently prevent the lid body from accidentally coming off.

[0037] Further, the porous body may be provided in the front space instead of the rear space.

[0038] Also, the second packing may have a convex portion on the third surface 43c, like the second packing 43' shown in FIG. 8(B). That is, the number of convex portions on the third surface 43c may be one or more. Further, the second packing may have one or more convex portions on the second surface 43b, like the third packing 43'' shown in FIG. 8(C). Providing convex portions on the second surface 43b enhances the adhesion to the lid body.

Explanation of Signs

[0039] 10 Electronic device 11 Interface portion 20 Housing 21 Front housing 22 Rear housing 23 First packing 24 First opening 25 Partition 26 Second opening 27 Wall portion 28 Third opening 29 Recess 30 Fourth opening 31 Screw 32 Screw 40 Lid body 41 Claw portion 42 Snap fit portion 43 Second packing 43a First surface 43b Second surface 43c Third surface (concave-convex surface) 50 Porous body

Claims

1. A waterproof structure for an electronic device having an electronic circuit accommodation space therein, comprising: a housing having a first opening; a lid detachably attached to the first opening in a snap-fit manner; and a porous body provided inside the housing; wherein the housing has a partition wall that divides the space inside the housing into the electronic circuit accommodation space and the remaining space; the partition wall has a second opening; the lid is configured to incompletely close the first opening and completely close the second opening when attached to the first opening, thereby waterproofing the electronic circuit accommodation space; the partition wall further has a third opening; the porous body is arranged to block the third opening; air in the electronic circuit accommodation space can be discharged to the remaining space through the third opening and the porous body; characterized by the above waterproof structure.

2. further comprising an annular packing provided on the lid; the partition wall has a wall portion surrounding the second opening; when the lid is attached to the first opening, the packing is in close contact with the wall portion; characterized by the waterproof structure according to claim 1.

3. the packing has a concavo-convex surface facing the wall portion; when the lid is attached to the first opening, the concavo-convex surface is in close contact with the wall portion; characterized by the waterproof structure according to claim 2.

4. the housing further has a fourth opening communicating the remaining space with the outside of the housing; characterized by the waterproof structure according to any one of claims 1 to 3.

5. the porous body has a Gurley number of 15 seconds or less; characterized by the waterproof structure according to any one of claims 1 to 3.

6. An electronic device having an electronic circuit accommodation space therein, comprising: a housing having a first opening; a lid detachably attached to the first opening in a snap-fit manner; a porous body provided inside the housing; an electronic circuit board and a battery accommodated in the electronic circuit accommodation space; wherein the housing has a partition wall that divides the space inside the housing into the electronic circuit accommodation space and the remaining space; the partition wall has a second opening; the lid is configured to incompletely close the first opening and completely close the second opening when attached to the first opening, thereby waterproofing the electronic circuit accommodation space; the partition wall further has a third opening; the porous body is arranged to block the third opening; Air within the electronic circuit accommodation space can be discharged into the remaining space through the third opening and the porous body. An electronic device characterized by this.

Images