JP2009295321A - Waterproof structure of opening and closing part of device case - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To ensure a superior waterproof property in a structure for waterproofing an opening/closing part such as a connector cover part or a battery cover part in a device like a portable telephone or digital camera. <P>SOLUTION: There is provided a waterproof structure such that a cover 1 is reclosably fitted in an opening portion 21 of a device case 2 through a packing, and packing fit surfaces 21a, 13a of both the opening portion 21 and the cover 1 have substantially a similarity shape with each other having a planar portion A and a curved surface portion B, wherein a gap between the packing fit surface 21a of the opening portion 21 and the packing fit surface 13a of the cover 1 in their opposed direction is made less for the curved surface portion B than the planar portion A (h<SB>t</SB>>h<SB>r</SB>). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a structure for waterproofing an opening / closing part such as a connector cover part or a battery cover part in a case of a device such as a mobile phone or a digital camera.

Some small electronic devices such as mobile phones include a connector connection part for charging and data input / output and a battery insertion part. The opening part opened in the device case as the connector connection part and the battery insertion part is The cover is openable and closable. Such a gap between the case opening and the cover is conventionally sealed by an O-ring to be waterproof (see the following patent document).
JP 2000-41722 A JP 2001-250629 A

  However, when the case opening and the cover fitted to be openable / closable have a shape having a flat surface portion and a curved surface portion, such as an oval shape as in Patent Document 2, for example, it is difficult to obtain good waterproof properties. Is pointed out. This will be described with reference to FIGS. FIG. 6 is an explanatory view showing an oval cover as an example of a shape having a flat surface portion and a curved surface portion, and FIG. 7 shows a cover having a shape with rounded square corners as an example of a shape having a flat surface portion and a curved surface portion. FIG. 8 is an explanatory view showing a conventional technique, and FIG. 9 is a cross-sectional view of a flat surface portion and a curved surface portion in FIG.

  The cover 100 shown in FIG. 6 or FIG. 7 is formed with an insertion portion 101 inserted into the opening 200a of the case 200 shown in FIG. 8 or FIG. 200 has a flange 102 facing the outer surface of 200. The outer peripheral surface of the insertion portion 101 has plane portions A and curved surface portions B alternately in the circumferential direction, and a groove 103 continuous in the circumferential direction is formed in the groove 103. A rubber material or rubber-like elasticity is formed in the groove 103. An O-ring 104 made of a synthetic resin material having is attached. In other words, as shown in FIG. 9, the cover 100 is configured such that the insertion portion 101 is press-fitted and fitted to the inner periphery of the opening portion 200 a of the device case 200 via the O-ring 104, thereby It is water-tight by blocking it.

Therefore, the opening 200 a of the device case 200 is also formed in a shape that is substantially similar to the projected shape in the insertion direction of the cover 100. Specifically, as shown in FIG. 8, the centers C of the radii of curvature R ₁ and R ₂ of the bottom surface of the groove 103 of the cover 100 in the curved surface portion B and the inner surface of the opening portion 200a of the device case 200 are the same. The size h _t of the gap between the bottom surface of the groove 103 and the inner surface of the opening 200a in the portion A, the size h _r of the gap between the bottom surface of the groove 103 and the inner surface of the opening 200a in the curved surface portion B, and The size h _s of the gap between the bottom surface of the groove 103 and the inner surface of the opening 200a at the boundary portion between the flat surface portion A and the curved surface portion B is the same and is appropriately smaller than the cross-sectional diameter of the O-ring 104 in the unmounted state. . For this reason, the O-ring 104 is sandwiched between the bottom surface of the groove 103 of the cover 100 and the inner surface of the opening 200a of the device case 200 in a properly compressed state.

However, since the O-ring 104 is attached to the groove 103 of the cover 100 in an appropriately extended state, the overall cross-sectional diameter is reduced as compared with the non-attached state, and the O-ring 104 is formed at the curved surface portion B by tension. As shown in FIG. 9, the cross-sectional diameter φ _B at the curved surface portion B is smaller than the cross-sectional diameter φ _A at the flat surface portion A. For this reason, in the curved surface portion B, the crushing margin of the O-ring 104 is smaller than that of the flat surface portion A, the sealing performance is lowered, and it is difficult to obtain a good waterproof property.

  The present invention has been made in view of the above points, and the technical problem is such as a connector cover or a battery cover in a case of a device such as a mobile phone or a digital camera. In the structure for waterproofing the opening / closing portion, it is intended to ensure excellent waterproofness even when the opening and the cover fitted to be openable / closable have a flat surface portion and a curved surface portion.

  As means for effectively solving the technical problem described above, the waterproof structure of the opening and closing part of the device according to the present invention is fitted into the opening of the device case so that the cover can be opened and closed via packing, In the case where both packing fitting surfaces of the cover have a substantially similar shape having a flat surface portion and a curved surface portion, a gap in the facing direction between the packing fitting surface of the opening and the packing fitting surface of the cover is provided. The curved surface portion is smaller than the flat surface portion.

  Moreover, it is preferable that the clearance gap of the opposing direction of the packing fitting surface of an opening part and the packing fitting surface of a cover changes continuously between a plane part and a curved surface part.

  According to the waterproof structure of the opening / closing portion of the device according to the present invention, when the packing fitting surface of the cover has a shape having a flat surface portion and a curved surface portion, the cover is attached to the outer peripheral surface of the cover in a properly extended state. Thus, even if the cross-sectional diameter of the packing is small at the curved surface portion, the gap in the facing direction between the packing fitting surface of the opening and the packing fitting surface of the cover is made smaller at the curved surface portion than at the flat surface portion. Thereby, since the crushing margin of substantially the same rate as that of the flat surface portion can be ensured for the packing whose cross-sectional diameter is narrow at the curved surface portion, it is possible to obtain a good waterproof property.

  Hereinafter, a waterproof structure of an opening / closing part of an apparatus according to the present invention will be described with reference to the drawings. First, FIG. 1 is a diagram showing a state in which a cover is fitted in an opening of an equipment case through a packing as viewed from the inside of the equipment case, and FIG. 2 is a schematic diagram showing the first form. Structure explanatory drawing and FIG. 3 are sectional views of a flat surface portion and a curved surface portion in FIG.

  In FIG. 1, reference numeral 1 is a cover, and reference numeral 2 is a device case such as a cellular phone. The device case 2 has an opening 21 for connecting a connector or mounting a battery, for example. The cover 1 is fitted into the opening 21 through the O-ring 3 so as to be openable and closable.

  As shown in FIG. 3, the cover 1 is formed so as to project from the insertion portion 11 to be inserted into the opening portion 21 of the device case 2 and the outer end portion of the insertion portion 11 so as to face the outer surface of the device case 2. It has the collar part 12 made. The outer peripheral surface of the insertion portion 11 has a shape in which the projection shape with respect to the insertion direction is a rounded square corner, that is, has a plane portion and a curved surface portion alternately in the circumferential direction, and the groove 13 continuous in the circumferential direction is formed. Is formed. The bottom surface 13a of the groove 13 (hereinafter referred to as the groove bottom surface 13a) corresponds to the “packing fitting surface of the cover” recited in claim 1.

  The O-ring 3 is made of a rubber material or a synthetic resin material having rubber-like elasticity, and is attached in a half-fitted state to a groove 13 formed on the outer peripheral surface of the insertion portion 11 of the cover 1. The O-ring 3 corresponds to the “packing” described in claim 1.

  The opening portion 21 opened in the device case 2 has an opening shape that is substantially similar to the outer peripheral surface of the insertion portion 11 of the cover 1, that is, a shape with rounded square corners. Therefore, the inner peripheral surface 21a of the opening 21 (hereinafter referred to as the opening inner peripheral surface 21a) also has a plane portion and a curved surface portion alternately in the circumferential direction. The opening inner peripheral surface 21 a corresponds to the “packing fitting surface of the opening” recited in claim 1.

In detail, as shown in FIG. 2, the curvature radius R ₂₁ of the opening inner peripheral surface 21 a of the device case 2 in the groove bottom surface 13 a and the curved inner surface 21 a of the opening inner peripheral surface _{21 a} is naturally of the groove bottom surface 13 a of the cover 1. larger than the radius of curvature _{R 13 (R 21> R 13),} center _{C 13} of the radius of curvature _{R 13} of the groove bottom surface 13a is positioned on the outer peripheral side from the center _{C 21} of the radius of curvature _{R 21} of the opening inner peripheral surface 21a, the groove a flat portion of the bottom surface 13a and the boundary point _{S 13} of the curved surface portion, a boundary point _{S 21} of the curved surface portion and the flat portion at the opening inner peripheral surface 21a is the same as viewed from the center _{C 13} of the radius of curvature _{R 13} of the groove bottom surface 13a phases Located on the top.

For this reason, the size h _s of the gap between the groove bottom surface 13a and the opening inner peripheral surface 21a at the boundary portion between the flat surface portion A and the curved surface portion B is equal to the groove bottom surface 13a and the opening inner peripheral surface 21a in the flat surface portion A. is identical to the size of h _t of the gap between, in the curved surface portion B, the size h _r of the gap between the groove bottom surface 13a and the opening inner peripheral surface 21a, the groove bottom surface 13a and the opening inner peripheral surface It decreases as the distance from the flat portion a of 21a, that is, a _{h t = h s> h r} . The size h _t of the gap in the plane portion A, appropriately smaller than the cross-sectional diameter of the O-ring 3 in the unmounted state.

Here, since the O-ring 3 is mounted in the groove 13 of the cover 1 in an appropriately extended state, the cross-sectional diameter φ _B at the curved surface portion B is particularly smaller than the cross-sectional diameter φ _A at the flat surface portion A. . Specifically, in the case of an O-ring having a cross-sectional diameter of 0.7 mm in an unmounted state, it has been confirmed that the cross-sectional diameter of the curved surface portion is smaller by about 0.02 to 0.05 mm than the flat surface portion. Thus, the gap _h t, _{h r} the compression rate of the O-ring 3 in the curved part _{B (φ B -h r) /} φ B are compression rate of the O-ring 3 in the flat portion _A (φ A -h _t) / phi set _a and _R 13 to be substantially _{equal, R 21, C 13, C} 21 , etc., specifically, the minimum value (circumferentially central portion of the curved surface portion B of the gap _{h r} of the curved surface portion B is _h magnitude of _r) in, it is preferable to set to be 94 to 98% of the gap size _{h t} in the plane section a.

  According to the above configuration, the cover 1 is press-fitted with the insertion portion 11 of the cover 1 to the opening 21 of the device case 2 via the O-ring 3, and the O-ring 3 includes the groove bottom surface 13 a and the opening inner peripheral surface 21 a. By being sandwiched in a properly compressed state, the opening 21 is closed in a sealed state to achieve waterproofing.

And as previously described, O-ring 3 is the cross-sectional diameter phi _B of the curved surface portion B is smaller than the cross-sectional diameter phi _A of the plane portion A, according to the configuration of the present invention, the equipment case 2 of the opening By reducing the size of the gap in the facing direction between the inner peripheral surface 21a and the groove bottom surface 13a of the cover 1 at the curved surface portion B from the flat surface portion A (h _t > h _r ), the curved surface portion B as described above. With respect to the O-ring 3 having a small cross-sectional diameter, a crushing margin substantially equivalent to that of the flat portion A can be ensured, and good waterproofness can be obtained.

  Next, FIG. 4 is a schematic configuration explanatory view showing a second embodiment of the present invention, and FIG. 5 is a cross-sectional view of the flat portion, the curved surface portion, and the boundary portion between the flat portion and the curved surface portion in FIG.

  In the second embodiment, the difference from the first embodiment described above is that the size of the gap in the facing direction between the opening inner peripheral surface 21a of the device case 2 and the groove bottom surface 13a of the cover 1 is the flat portion A. And the curved surface portion B continuously change. Other parts can be configured in the same manner as in the first embodiment.

Specifically, the radius of curvature _{R 21} of the opening inner peripheral surface 21a of the device case 2 in curved part B is larger than the radius of curvature _{R 13} of the groove bottom surface 13a of the cover 1 _{(R 21> R 13),} the curvature of the groove bottom surface 13a radius R ₁₃ center of _{C 13} is located radially outward of the center _{C 21} of the radius of curvature _{R 21} of the opening inner peripheral surface 21a, the boundary point _{S 13} of the curved surface portion flat portion of the groove bottom surface 13a, the curvature of the groove bottom surface 13a radius located on a line perpendicular to the flat portion of the groove bottom surface 13a through the center C ₁₃ of R _13, a boundary point S ₂₁ of the curved surface portion and the flat portion at the opening inner peripheral surface 21a is, the radius of curvature of the opening peripheral face 21a through the center _{C 21} of R ₂₁ located on a straight line perpendicular to the plane of the opening in the peripheral surface 21a, i.e. boundary point _{S 13, S 21} are on different phase from each other when viewed from the _{C 13} or _{C 21.}

Therefore, the plane of the opening in the peripheral surface 21a is extend tangentially with respect to the curved surface portion of the opening inner peripheral surface 21a, that is, smoothly continuous at the boundary point S ₂₁ of the curved surface portion and the flat portion, similarly, flat portion of the groove bottom surface 13a is extend tangentially with respect to the curved surface portion of the groove bottom surface 13a, that is smoothly continuous at the boundary point S ₁₃ of the curved surface portion and the flat portion.

Therefore, the gap between the groove bottom surface 13a and the opening inner peripheral surface 21a at the position of the boundary point S ₂₁ magnitude h _S2 is the gap between the groove bottom surface 13a and the opening inner peripheral surface 21a of the flat portion A is identical to the size _{h t,} gap size _{h S1} between the groove bottom surface 13a and the opening inner peripheral surface 21a at the position of the boundary point _{S 13 is} slightly smaller than _{h S2,} the curved surface portion B , the size h _r of the gap between the groove bottom surface 13a and the opening inner peripheral surface 21a is smaller as the distance from the flat portion a of the groove bottom face 13a and the opening inner peripheral surface 21a. That is, the gap between the groove bottom surface 13a and the inner peripheral surface 21a of the opening continuously changes from h _t to h _r (h _t = h _S2 > h _S1 > h _r ). The size h _t of the gap in the plane portion A, appropriately smaller than the cross-sectional diameter of the O-ring 3 in the unmounted state.

The opposite such by the structure, and the O-ring 3 in the cross-sectional diameter phi _A slightly smaller in the vicinity of the boundary point S ₁₃ than the cross-sectional diameter phi _S to the opening inner peripheral surface 21a and the groove bottom surface 13a of the flat portion A The crushing rate (φ _S −h _S1 ) / φ _S in this portion is substantially equal to the crushing rate (φ _A −h _t ) / φ _{A in} the plane portion A as the gap in the direction follows. That is, the change in the gap in the facing direction between the opening inner peripheral surface 21a and the groove bottom surface 13a better corresponds to the change in the cross-sectional diameter of the O-ring 3 between the flat surface portion A and the curved surface portion B. Therefore, good waterproofness can be obtained.

  In the illustrated embodiment, the groove bottom surface 13a and the opening inner peripheral surface 21a have a shape with rounded square corners. However, the present invention is not limited to this, and for example, FIG. The present invention can be similarly applied to an oval shape such as.

It is the figure which looked at the state by which the cover was fitted in the opening part of the equipment case so that opening and closing was possible via the packing as a 1st form of the waterproof structure of the opening-and-closing part of the equipment concerning the present invention. BRIEF DESCRIPTION OF THE DRAWINGS It is schematic structure explanatory drawing which shows the 1st form of this invention. It is sectional drawing of the plane part and curved surface part in FIG. It is schematic structure explanatory drawing which shows the 2nd form of this invention. It is sectional drawing of the boundary part of the plane part in FIG. 4, a curved surface part, and a plane part and a curved surface part. It is explanatory drawing which shows an oval cover. It is explanatory drawing which shows the cover of the shape which rounded the square corner | angular. It is explanatory drawing which shows the prior art. It is sectional drawing of the plane part and curved surface part in FIG.

Explanation of symbols

1 Cover 13 Groove 13a Groove bottom face (cover packing fitting surface)
2 device case 21 opening 21a inner peripheral surface of opening (packing fitting surface of opening)
3 O-ring (packing)
A Plane part B Curved part

Claims (2)

  In the opening of the device case, the cover is fitted so as to be openable and closable via packing, and the packing fitting surfaces of both the opening and the cover have a substantially similar shape having a flat surface portion and a curved surface portion. A waterproof structure for an opening / closing part of an equipment case, wherein a gap in a facing direction between the packing fitting surface of the opening and the packing fitting surface of the cover is made smaller at the curved surface portion than at the flat portion.   The opening and closing of the device case according to claim 1, wherein a gap in a facing direction between the packing fitting surface of the opening and the packing fitting surface of the cover continuously changes between the flat surface portion and the curved surface portion. Part waterproof structure.

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