1. Technical Field
The present invention relates to a structure for achieving waterproofness of an opening and closing portion such as a connector cover portion, a battery cover portion or the like in a case of a device.
2. Description of the Conventional Art
In a compact electronic device such as a cellular phone, a digital camera or the like, there is a structure which is provided with a connector connection portion and a battery insertion portion for inputting and outputting data and charging, and a cover is detachably fitted to an opening portion which is provided as the connector connection portion or the battery insertion portion in the device case. Further, a gap between the case opening portion and the cover mentioned above has been conventionally sealed by an O-ring, thereby achieving waterproofness.
However, in accordance with the conventional waterproof structure, in a process of fitting the cover 200 to the opening portion 101 as shown in
Further, at a time of winding the O-ring 202 in the installation groove 201 of the cover 200, torsion tends to be caused in the O-ring 202, and there is a risk that the sealing performance (the waterproof performance) is deteriorated by poor installation.
The present invention is made by taking the point mentioned above into consideration, and a technical problem thereof is to prevent reduction of a waterproof performance and poor installation due to torsion of a packing within an installation groove.
As a means for effectively solving the technical problem mentioned above, a waterproof structure in accordance with the first aspect of the present invention is a structure in which a packing is installed to an installation groove which is peripherally provided in an outer peripheral surface of a cover, and the packing is compressed between an inner surface of an opening portion and a bottom surface of the installation groove by fitting the cover to the opening portion of a case of a device, the structure being characterized in that the packing has a flat shape at a close contact surface with the bottom surface of the installation groove, and a cross sectional diameter in a width direction of the packing is made larger than a cross sectional diameter thereof in a height direction.
Further, a waterproof structure in accordance with the second aspect of the present invention is a structure in which a packing is installed to an installation groove which is peripherally provided in an outer peripheral surface of a cover, and the packing is compressed between an inner surface of an opening portion and a bottom surface of the installation groove by fitting the cover to the opening portion of a case of a device, the structure being characterized in that the packing has a flat cross sectional shape at a close contact surface with the bottom surface of the installation groove, that is, an inner peripheral surface in accordance that the installation groove has a flat cross sectional shape at its bottom surface, has a circular arc shaped convex surface at an outer periphery surface at the opposite side, and is formed to have a D-shaped cross section as a whole.
Further, a waterproof structure in accordance with the third aspect of the present invention is a structure in which a packing is installed to an installation groove which is peripherally provided in an outer peripheral surface of a cover, and the packing is compressed between an inner surface of an opening portion and a bottom surface of the installation groove by fitting the cover to the opening portion of a case of a device, the structure being characterized in that a fitting groove extending in an extending direction of the installation groove is formed in the bottom surface of the installation groove, and a fitting projection capable of fitting to the fitting groove is formed on the packing.
Further, a waterproof structure in accordance with the fourth aspect of the present invention is the waterproof structure of an opening and closing portion of a device case as described in the third aspect mentioned above, the structure being further characterized in that the packing has a flat cross sectional shape at a close contact surface with the bottom surface of the installation groove, that is, an inner peripheral surface in accordance that the installation groove has a flat cross sectional shape at its bottom surface, has a circular arc shaped convex surface at an outer periphery at the opposite side, and is formed to have a D-shaped cross section as a whole, and the fitting projection is formed on an inner peripheral surface of the packing formed to have the D-shaped cross section.
Further, a waterproof structure in accordance with the fifth aspect of the present invention is the waterproof structure of an opening and closing portion of a device case as described in the third aspect mentioned above, the structure being further characterized in that the packing is formed to have a crucial cross sectional shape while having a fitting projection at an inner peripheral side fitting to the fitting groove, a seal projection at an outer peripheral side coming into close contact with an inner surface of the opening portion, and seal projections at both sides in a width direction, in accordance that the installation groove has a flat cross sectional shape at its bottom surface.
Further, a waterproof structure in accordance with the sixth aspect of the present invention is a structure in which a packing is installed to an installation groove which is peripherally provided in an outer peripheral surface of a cover, and the packing is compressed between an inner surface of an opening portion and a bottom surface of the installation groove by fitting the cover to the opening portion of a case of a device, the structure being characterized in that the packing has a flat shape at a close contact surface with the bottom surface of the installation groove, and a close contact surface with an inner surface of the opening portion is constructed by a peak portion and inclined surfaces at both sides thereof.
Further, a waterproof structure in accordance with the seventh aspect of the present invention is a structure in which a packing is installed to an installation groove which is peripherally provided in an outer peripheral surface of a cover, and the packing is compressed between an inner surface of an opening portion and a bottom surface of the installation groove by fitting the cover to the opening portion of a case of a device, the structure being characterized in that the packing has a flat cross sectional shape at a close contact surface with the bottom surface of the installation groove, that is, an inner peripheral surface in accordance that the installation groove has a flat cross sectional shape at its bottom surface, has a shape provided with a peak portion and inclined surfaces at both sides thereof at an outer peripheral surface at the opposite side, and is formed to have a pentagonal cross sectional shape as a whole.
Further, a waterproof structure in accordance with the eighth aspect of the present invention is the waterproof structure of an opening and closing portion of a device case as described in the sixth or seventh aspect mentioned above, the structure being further characterized in that the inclined surface at a cover inserting direction side is a relatively gentle slope, and the inclined surface at the opposite side to the cover inserting direction is a relatively steep slope, in the inclined surfaces at both sides of the peak portion of the packing.
Further, a waterproof structure in accordance with the ninth aspect of the present invention is the waterproof structure of an opening and closing portion of a device case as described in the sixth or seventh aspect mentioned above, the structure being further characterized in that the inclined surface at a cover inserting direction side is a relatively gentle slope, and the inclined surface at the opposite side to the cover inserting direction is a relatively steep slope, in the inclined surfaces at both sides of the peak portion of the packing, and the peak portion of the packing is deviated from a center portion in the width direction of the packing toward the opposite side to the cover inserting direction.
In the waterproof structure in accordance with the first aspect of the present invention having the structure mentioned above, since the packing has the flat shape at the close contact surface with the bottom surface of the installation groove, and the cross sectional diameter in the width direction is set to be larger than the cross sectional diameter in the height direction, seating on the bottom surface of the installation groove is stabilized in comparison with the conventional O-ring which tends to roll, and the packing is hardly twisted even by being exposed to a load in the twisting direction, whereby it is possible to effectively prevent reduction of a waterproof performance.
Further, in the waterproof structure in accordance with the second aspect of the present invention, since the packing has the flat cross sectional shape at the close contact surface with the bottom surface of the groove, that is, the inner peripheral surface in accordance that the installation groove has the flat cross sectional shape at its bottom surface, has the circular arc shaped convex surface at the outer periphery surface at the opposite side, and is formed to have the D-shaped cross section as a whole, seating on the bottom surface of the installation groove is stabilized in comparison with the conventional O-ring which tends to roll, and the packing is hardly twisted even by being exposed to a load in the twisting direction, whereby it is possible to effectively prevent reduction of the waterproof performance.
Further, in the waterproof structure in accordance with the third, fourth or fifth aspect of the present invention, since the fitting projection formed on the packing is fitted to the fitting groove formed in the bottom surface of the installation groove, the packing is constrained within the installation groove in accordance with the fitting, and the package is hardly twisted even by being exposed to a load in the twisting direction, whereby it is possible to effectively prevent reduction of the waterproof performance. In accordance with the structure of the fourth aspect, since the inner peripheral surface of the packing has the flat cross sectional shape, seating on the bottom surface of the installation groove is stabilized. In accordance with the structure of the fifth aspect, since the seal projections protruding to both sides in the width direction come into close contact with the bottom surface of the installation groove, seating on the bottom surface of the installation groove is stabilized. Further, since the width in the axial direction of the seal projection at the outer peripheral side coming into close contact with the inner surface of the opening portion is set to be smaller than the width in the axial direction of a whole of the packing, compressive reaction force in an installed state is set to be smaller.
Further, in the waterproof structure in accordance with the sixth aspect of the present invention, since the close contact surface with the bottom surface of the installation groove in the packing has the flat shape, seating on the bottom surface of the installation groove is stabilized in comparison with the conventional O-ring which tends to roll, and the packing is hardly twisted even by being exposed to a load in the twisting direction, whereby it is possible to effectively prevent the reduction of the waterproof performance. Further, since the close contact surface with the inner surface of the opening portion of the case is constructed by the peak portion and the inclined surfaces at both sides thereof, the compressive reaction force becomes smaller in comparison with the structure in which the close contact surface with the inner surface of the opening portion is formed into the circular arc shaped convex surface, in the case that a collapsing margin is fixed, whereby it is possible to reduce press-fit resistance at a time of fitting the cover to the opening portion of the case, and abrasion of the packing. Therefore, it is possible to prevent poor installation of the packing and torsion of the packing within the groove on the basis of repeated opening and closing motions of the cover or the like, it is further possible to reduce the press-fit resistance at a time of fitting the cover to the opening portion of the case, and it is possible to suppress reduction of the waterproof performance due to the abrasion.
Further, in the waterproof structure in accordance with the seventh aspect of the present invention, since the packing has the flat cross sectional shape at the close contact surface with the bottom surface of the installation groove, that is, the inner peripheral surface in accordance that the installation groove has the flat cross sectional shape at its bottom surface, seating on the bottom surface of the installation groove is stabilized in comparison with the conventional O-ring which tends to roll, and the packing is hardly twisted even by being exposed to a load in the twisting direction, whereby it is possible to effectively prevent the reduction of the waterproof performance. Further, since the packing has the cross sectional shape provided with the peak portion and the inclined surfaces at both sides thereof at the outer peripheral surface at the opposite side to the inner peripheral surface, and is formed to have the pentagonal cross sectional shape as a whole, the compressive reaction force becomes smaller in comparison with the structure in which the close contact surface with the inner surface of the opening portion is formed into the circular arc shaped convex surface, in the case that a collapsing margin is fixed, whereby it is possible to reduce press-fit resistance at a time of fitting the cover to the opening portion of the case, and abrasion of the packing. Therefore, it is possible to prevent poor installation of the packing and torsion of the packing within the groove on the basis of repeated opening and closing motions of the cover or the like, it is further possible to reduce the press-fit resistance at a time of fitting the cover to the opening portion of the case, and it is possible to suppress reduction of the waterproof performance due to the abrasion.
Further, in the waterproof structure in accordance with the eighth or ninth aspect of the present invention, friction resistance of the packing with the inner surface of the opening portion of the case becomes smaller in a cover inserting direction and larger in the opposite direction thereto. Further, since surface pressure of the packing with respect to the inner surface of the opening portion of the case more rapidly rises at the opposite side to the cover inserting direction than the peak portion, resistance against intruding pressure of water from the external is increased. Accordingly, the cover can be fitted easier to the opening portion of the case, the cover can be firmly fitted so as to hardly fall away from the opening portion of the case, and it is possible to further improve the waterproof performance.
A description will be given below of preferable embodiments of a waterproof structure of an opening and closing portion of a device in accordance with the present invention with reference to the accompanying drawings.
First of all, in a perspective view of
The opening portion 11 provided in the case 1 is structured such that an opening shape is formed as a square shape having round corners. In other words, an inner peripheral surface thereof has flat surface portions and curved surface portions alternately in a peripheral direction.
The cover 2 is formed in a tabular shape as a whole, and has an insertion portion 21 which can be inserted to the opening portion 11 of the case 1, and a collar portion 22 which is formed so as to protrude out of an outer end portion of the insertion portion 21 and is opposed to an outer surface 1a of the case 1, as shown in
An outer peripheral surface 21a of the insertion portion 21 of the cover 2 is formed in its projection shape in an inserting direction, to have an approximately similar shape to the opening shape of the opening portion 11 of the case 1, that is, a square shape having round corners as shown in
A packing 3 made of a rubber-like elastic material (a rubber material or a synthetic resin material having a rubber-like elasticity) is installed to the installation groove 23 mentioned above. The packing 3 is molded in an annular shape as shown in
Further, as shown in
In the structure mentioned above, the cover 2 is structured such that the insertion portion 21 thereof is press fitted to the opening portion 11 of the case 1 via the packing 3, and the packing 3 is held in a state of being appropriately compressed between the bottom surface 23a of the installation groove 23 and the inner peripheral surface 11a of the opening portion 11, thereby closing the opening portion 11 in a sealed state so as to achieve waterproofness.
Further, in accordance with the present invention, since the inner peripheral surface 3a brought into close contact with the bottom surface 23a of the installation groove 23 is flat and the relation of L2/L1<1 is established, in the packing 3, resistance at a time when force in a rolling (twisting) direction acts is large. Accordingly, the packing 3 is not twisted on the basis of friction with the inner peripheral surface 11a of the opening portion 11 and the bottom surface 23a of the installation groove 23, in a process of fitting the cover 2 to the opening portion 11 as shown in
Further, since the packing 3 is molded in an annular shape as shown in
Next,
In
An outer peripheral surface 21a of the insertion portion 21 of the cover 2 has, in its projection shape with respect to an inserting direction, an approximately similar shape to the opening shape of the opening portion 11 of the case 1, that is, a square shape having round corners as shown in
The installation groove 23 is constructed by a bottom surface 23a which has a flat cross sectional shape and is in parallel to the outer peripheral surface 21 a of the insertion portion 21 of the cover 2, and a pair of inner surfaces 23b which approximately vertically rise from both sides thereof, and a fitting groove 24 which extends in an extending direction of the installation groove 23 and has a C-shaped cross sectional shape is formed at an intermediate position in a width direction of the bottom surface 23a.
The packing 3 is molded in an annular shape as shown in
In detail, the main body portion 31 of the packing 3 is retained within the installation groove 23, the inner peripheral surface 31a brought into close contact with the bottom surface 23a of the installation groove 23 has a flat cross sectional shape, an outer peripheral surface 31b protruding out to an outer side of the installation groove 23 so as to be brought into pressure contact with the inner peripheral surface 11a of the opening portion 11 of the case 1 in an appropriate deformed state is formed into a convex surface having a circular arc shaped cross section, and slight gaps are provided with respect to the inner surfaces 23b of the installation groove 23 so that a filling rate of the main body portion 31 within the installation groove 23 does not become 100% or more even in a state of being compressed between the bottom surface 23a of the installation groove 23 and the inner peripheral surface 11a of the opening portion 11. Further, the fitting projection 32 is structured such as to be brought into close contact with and fitted to a fitting groove 24 formed in the bottom surface 23a of the installation groove 23.
In the waterproof structure in accordance with the second embodiment structured as mentioned above, as shown in
Further, since the packing 3 is bound by the fitting projection 32 being brought into close contact with and fitted to the fitting groove 24 formed in the bottom surface 23a of the installation groove 23, resistance at a time when force F in a rolling (twisting) direction shown in
Further, if the fitting projection 32 is pushed into the fitting groove 24 of the bottom surface 23a of the installation groove 23 while pressing the main body portion 31 lightly, at a time of fitting the packing 3 onto the insertion portion 21 of the noncircular cover 2 so as to wind it in the installation groove 23, the fitting projection 32 is fitted into the fitting groove 24 sequentially. Accordingly, torsion of the packing 3 (the main body portion 31) is not caused, and it is possible to effectively prevent the sealing performance (the waterproof performance) from being deteriorated by poor installation.
Next,
In more detail, the fitting groove 24 formed at an intermediate position in a width direction of the bottom surface 23a of the installation groove 23 has an approximately U-shaped cross section, as shown in
Further, the packing 3 has an inner peripheral side fitting projection 32 which has a convex surface having a circular arc shaped cross section corresponding to the fitting groove 24, an outer peripheral side seal projection 33 having a cross sectional shape which is 180 degree symmetrical with the fitting projection 32, and seal projections 34 and 35 at both sides in a width direction having cross sectional shapes which are 90 degree symmetrical with the fitting projection 32 in 90 degree different directions from the fitting projection 32 and the seal projection 33 respectively, in a cross section shown in
Further, the fitting projection 32 of the packing 3 is brought into close contact with and fitted to a fitting groove 24 formed in the bottom surface 23a of the installation groove 23, and the seal projection 33 at the outer peripheral side protrudes to the outer side of the installation groove 23 so as to be brought into pressure contact with the inner peripheral surface 11a of the opening portion 11 of the case 1 in an appropriate deformed state. Further, the seal projections 34 and 35 at both sides in the width direction are brought into close contact with the inner surfaces 23b and 23b of the installation groove 23 at their top ends as well as being retained within the installation groove 23, and their inner peripheral portions are brought into close contact with the bottom surface 23a of the installation groove 23. Since they have a convex surface having a circular arc shaped cross section, slight gaps are formed with respect to the bottom surface 23a and the inner surfaces 23b of the installation groove 23, and a filling rate of the packing 3 within the installation groove 23 does not become 100% or more.
In the waterproof structure in accordance with the third embodiment constructed as mentioned above, as shown in
Further, since the packing 3 is structured such that the fitting projection 32 at the inner peripheral side is brought into close contact with and fitted to the fitting groove 24 formed in the bottom surface 23a of the installation groove 23, and the top ends of the seal projections 34 and 35 at both sides in the width direction are brought into close contact with the inner surfaces 23b and 23b of the installation groove 23, resistance at a time when force F in the rolling (twisting) direction shown in
Further, if the fitting projection 32 is pressed into the fitting groove 24 of the bottom surface 23a of the installation groove 23 while pushing lightly the seal projections 33 to 35 at a time of fitting the packing 3 onto the insertion portion 21 of the noncircular cover 2 so as to wind it in the installation groove 23, the fitting projection 32 is fitted into the fitting groove 24 sequentially. Accordingly, torsion of the packing 3 (the main body portion 31) is not caused, and it is possible to effectively prevent the sealing performance (the waterproof performance) from being deteriorated by poor installation.
In this case, in the present invention, the fitting projection 32 may not be necessarily continuous in an endless shape in the extending direction of the packing 3, but may be intermittent. In accordance with this, it is not necessary to carry out the work of fitting the fitting projection 32 to the installation groove 24 all over the periphery at a time of installing the packing 3, and it is possible to prevent air from being included in the fitting groove 24.
Next,
The opening portion 11 provided in the case 1 is structured such that an opening shape is, for example, a square shape having round corners such as an example in
The cover 2 has a tabular shape as a whole, and has an insertion portion 21 which can be inserted to the opening portion 11 of the case 1, and a collar portion 22 which is formed so as to protrude out of an outer end portion of the insertion portion 21 and is opposed to an outer surface 1a of the case 1.
The insertion portion 21 of the cover 2 is formed, in its projection shape with respect to an inserting direction, in an approximately similar shape to the opening shape of the opening portion 11 of the case 1, for example, a square shape having round corners as an example shown in
A packing 3 made of a rubber-like elastic material (a rubber material or a synthetic resin material having a rubber-like elasticity) is installed to the installation groove 23 of the cover 2.
The packing 3 is molded in an annular shape so as to have a pentagonal cross sectional shape. As shown in
In a concrete example shown in
In the fourth embodiment structured as mentioned above, the cover 2 is structured such that the insertion portion 21 is press fitted to the opening portion 11 of the case 1 via the packing 3 and the packing 3 is held in a state of being appropriately compressed between the bottom surface 23a of the installation groove 23 and the inner surface 11a of the opening portion 11, thereby closing the opening portion 11 in a sealed state so as to achieve waterproofness.
Further, in the packing 3, since the inner peripheral surface 3a brought into close contact with the bottom surface 23a of the installation groove 23 has the flat shape, resistance at a time when force in a rolling (twisting) direction acts is large, and friction resistance with respect to the inner surface 11a of the opening portion 11 on the basis of compressive reaction force is small in addition as mentioned below. Accordingly, the packing 3 is not twisted in a process of fitting the cover 2 to the opening portion 11 as shown in
Further, in this packing 3, the compressive reaction force becomes smaller, in comparison with the packing 3 having the D-shaped cross section, that is, having the convex surface in the circular arc cross sectional shape at its outer peripheral surface 3b, which is described previously and shown in
Further, since the inner peripheral surface 3a brought into close contact with the bottom surface 23a of the installation groove 23 has the flat shape as mentioned above, the packing 3 is hardly twisted even in the installing process to the installation groove 23, whereby it is possible to effectively prevent the sealing performance (the waterproof performance) from being deteriorated by poor installation.
Next,
In this fifth embodiment, a difference from the fourth embodiment mentioned above exists in a matter that the peak portion 3e of the packing 3 is deviated from the center in the width direction toward the opposite side to the cover inserting direction (a side of the collar portion 22 of the cover), as shown in
Therefore, in accordance with this structure mentioned above, similarly to the fourth embodiment, it is possible to effectively prevent torsion of the packing 3, and it is possible to reduce abrasion of the packing 3.
Further, since the friction resistance of the packing 3 with respect to the inner surface 11a of the opening portion 11 of the case 1 becomes smaller in the cover inserting direction on the basis of the relation of α<β, press-fit resistance at a time of fitting the cover 2 to the opening portion 11 as shown in
Further, since the peak portion 3e of the packing 3 is deviated from the center in the width direction toward the opposite side to the cover inserting direction, surface pressure P with respect to the inner surface 11a of the opening portion 11 of the case 1 is distributed so as to rapidly rise at the opposite side to the cover inserting direction, as shown in
In this case, since there is a risk that the sealing performance is lowered and smooth opening and closing of the cover 2 become hard, if an offset amount of the peak portion 3e of the packing 3 is too large, it is desirable to set a ratio of L3:L4 within a range between 1:1 and 5:1.
Next,
In this sixth embodiment, the peak portion 3e is positioned at the center in the width direction of the packing 3, a slope α of the inclined surface 3f at the cover inserting direction side is a relatively gentle slope, and a slope β of the inclined surface 3g at the opposite side to the cover inserting direction is a relatively steep slope, that is, a relation of α<β is established in the inclined surfaces 3f and 3g at both sides of the peak portion 3e. Therefore, in accordance with the difference of the slopes α and β, a skirt portion 3h of the inclined surface 3g at the opposite side to the cover inserting direction is formed in a concave surface shape. The other portions can be structured basically the same as the fifth embodiment.
Further, in accordance with this structure, similarly to the fifth embodiment, it is possible to reduce abrasion of the packing 3 as well as effectively preventing torsion of the packing 3. Further, the same effect as the fifth embodiment can be obtained on the basis of the relation of α<β. In other words, the friction resistance of the packing 3 with respect to the inner surface 11a of the opening portion 11 of the case 1 becomes smaller in the cover inserting direction and becomes larger in the opposite direction to the cover inserting direction. In addition, surface pressure with respect to the inner surface 11a of the opening portion 11 of the case is distributed so as to rapidly rise at the opposite side to the cover inserting direction, and resistance against pressure of intrusion of water from the external is increased.
Further, in accordance with the sixth embodiment, in the case that the width w, the height h, the collapsing margin δ and the like of the packing 3 shown in
Number | Date | Country | Kind |
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2009-113544 | May 2009 | JP | national |
2009-155369 | Jun 2009 | JP | national |
This application is a U.S. National Stage Application of International application No. PCT/JP2010/053825 filed on Mar. 9, 2010, and published in Japanese as WO 2010128606 A1 on Nov. 11, 2010. This application claims priority to Japanese Application No. 2009-113544 filed May 8, 2009 and Japanese Application No. 2009-155269 filed Jun. 30, 2009. The disclosures of the above applications are incorporated herein by reference.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/JP2010/053825 | 3/9/2010 | WO | 00 | 9/19/2011 |