JPH1037940A - Waterproof structure and waterproof case for screw fixing part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure waterproof around a screw through hole by constructing a waterproof structure for a screw fixing part so that an O-ring is deformed elastically so as to be brought into contact with the circumference wall part and the bottom part of a recess and the back side of a head part of a screw. SOLUTION: When a thread part 50b in a screw 50 is screwed to an insert nut 17 via the first screw through hole 26, the back side of a head part 50a of the screw 50 and an O-ring 40 are brought into contact with each other, and the O-ring 40 is pressed toward a bottom part 25a in a recess part 25 and is deformed elastically in the circumference wall part 25b direction of the recess part 25 and in the base part 50c direction of the screw 50. As a result, the O-ring 40 is brought into contact with four parts, which are the back side of the head part 50a of the screw 50, the bottom part 25a and the circumferential wall part 25b of the recess part 25, and a base part 50c of the screw 50, so as to be brought into tight contact with them without any clearance. In this way, the O-ring 40 is brought into contact with the first screw through hole 26 circumference, and water penetration from the first screw hole 26 to a waterproof case can be prevented, so that waterproof structure can be accomplished.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waterproof structure for a screw fixing portion and a waterproof case using the same, and more particularly, to a waterproof case comprising a storage body and a storage cover body and having an internal package mounted therein. The present invention relates to a waterproof structure and a waterproof case of a screw fixing portion in which the storage body, the storage cover, and the internal package are integrally fixed and water does not enter the inside of the waterproof case.

[0002]

2. Description of the Related Art FIG. 4 shows an example of a conventional resin waterproof case having a split structure. Reference numeral 10B denotes a housing, and at the tip of the outer peripheral wall of the housing 10B,
An insert nut (screw hole) 17C is provided on the outside of the case, an outer peripheral groove 12B is formed on the inner side of the case, and a packing 30B is housed in the outer peripheral groove 12B. An insert nut fixing portion 14B and an insert nut (screw hole) 17B fixed in the insert nut fixing portion 14B are provided on the bottom surface 13B of the housing 10B.

On the other hand, at the tip of the outer peripheral wall of the storage cover 20B,
An outer peripheral protrusion 22B corresponding to the outer peripheral groove 12B is provided, and a first screw through hole 26C corresponding to the insert nut 17C is further provided. Further, a second screw through hole 61B is provided in the internal mount 60B.

[0004] Inside the waterproof case, the second screw through hole 61B is provided on the insert nut 17B.
Are superimposed, and the screw portion 53b of the screw 53 is inserted into the insert nut 17B through the second screw through hole 61B.
Is screwed on. Thus, the internal package 60B is attached to the housing 10B, and the internal package fixing portion 62B is configured. The outer peripheral groove 12B and the outer peripheral convex portion 2 are provided at the outer peripheral portions of the storage body 10B and the storage cover 20B via the packing 30B.
2B and the screw portion 52b of the screw 52
Is screwed into the insert nut 17C via the first screw through hole 26C, and the housing 10B and the housing cover 20B are fixed to form a case fixing portion 21B.

FIG. 5 shows an example of another conventional waterproof case. Reference numeral 10A denotes a storage body, and an outer peripheral groove 12A is formed at the tip of the outer peripheral wall of the storage body 10A, and a packing 30A is housed in the outer peripheral groove 12A. On the other hand, the bottom surface 13A of the storage body 10A
A substantially hollow cylindrical insert nut fixing portion 14A is provided perpendicular to 3A, and a metal insert nut (screw hole) 17A is provided in the insert nut fixing portion 14A.
Are fixed by insert molding.

An outer peripheral projection 22A corresponding to the outer peripheral groove 12A is provided at the distal end of the outer peripheral wall of the storage cover 20A that forms a waterproof case together with the storage body 10A. Further, on the upper surface of the storage cover 20A, there is provided a cylindrical recessed portion 23A that opens toward the upper surface of the storage cover 20A and protrudes in the direction of the storage body 10A so as to correspond to the insert nut 17A. A first screw through-hole 26A is provided in the bottom 24A. Further, a second screw through-hole 61A is provided in the internal mount 60A disposed between the recess 23A and the insert nut 17A.

[0007] The screw portion 51b of the special processing screw 51
The insert nut 17A is provided through a first screw through hole 26A provided in the housing cover 20A and a second screw through hole 61A provided in the internal package 60A.
The housing cover 20A, the inner package 60A, and the housing 10A are integrally fixed by being screwed into the waterproof case, and the inner package 60A is attached to the inside of the waterproof case. And the outer peripheral projection 22A are fitted through the packing 30A,
The waterproof case is formed by being sealed by the action of the packing 30A.

At this time, the area around the first screw through hole 26A is
Sealing is performed by the action of the special processing screw 51 so that water or the like does not enter the inside of the waterproof case from the first screw through hole 26A. This special processing screw 51
For example, a waterproof coating is provided, and a packing 51c is integrally provided on a contact surface of the head 51a with the housing cover 20A.

[0009]

However, the one shown in FIG. 4 described above has a poor space efficiency and requires waterproof because two parts, the internal mounting part fixing part 62B and the case fixing part 21B, need to be fixed by screws. It is difficult to reduce the size of the case. Further, since the outer circumferential groove 12B is provided in the housing 10B on the inner side of the waterproof case than the insert nut 17C, the thickness of the bottom surface 13B is not uniform. That is, the bottom surface 13 corresponding to the outer peripheral groove portion 12B
B becomes thicker, sink marks a occur on the bottom surface 13B of this portion, and there may be a problem in appearance quality.

FIG. 5 shows a special processing screw 5.
Since 1 is used, there is a problem that the unit cost of parts increases. That is, since the waterproofness of the specially processed screw 51 is enhanced by the integrated packing 51c and the waterproof coating as described above, the price is higher than that of a normal screw. Further, washers for preventing loosening of commonly used screws cannot be attached to the specially machined screw 51, and therefore, a work for preventing loosening is performed instead. Also, insert nut 1
Since the secondary processing for preventing screw loosening must be performed on 7A, the cost is further increased.

The present invention has been made in view of the above circumstances, and in a waterproof case comprising a storage body and a storage cover, and an internal package mounted inside the storage case,
As a screw fixing part for fixing the storage cover and the internal mounting object, the waterproof structure of the screw fixing part, which is excellent in space efficiency, hardly causes poor appearance of the waterproof case, and can use ordinary screws, was used. It is intended to provide a waterproof case.

[0012]

The object of the present invention is to provide an article having a screw hole formed therein and another article having a screw through hole formed therein by screwing a screw into the screw hole via the screw through hole. In the screw fixing portion fixed by doing so, a recess facing the screw through hole is formed around the screw through hole, an O-ring for sealing is housed in this recess, and a screw is screwed. The O-ring is elastically deformed to form a waterproof structure of the screw fixing portion so that the O-ring is in contact with at least the peripheral wall and the bottom of the recess and the back side of the head of the screw, thereby ensuring waterproofness around the screw through hole. Thus, the above-mentioned problem can be solved.

Further, the waterproof structure of the screw fixing portion described above can be used for a waterproof case. That is, in a waterproof case in which a housing and a housing cover are fitted to each other at their outer peripheral portions in a liquid-tight manner and an internal package is mounted therein, the housing or the housing cover is provided. A screw hole is formed in one of the two, a first screw through-hole is formed in the other, a second screw through-hole is provided in the internal mounting, the periphery of the first screw through-hole A recess facing the first screw through hole is formed, an O-ring for sealing is housed in the recess, and a screw is inserted through the first screw through hole and the second screw through hole. Is screwed into the screw hole, and the O-ring is elastically deformed so as to contact at least the peripheral wall and bottom of the recess and the back side of the head of the screw. It is possible to provide a waterproof case in which the property is ensured.

Further, a screw hole is provided on the bottom surface of the housing, and a recess is provided on the upper surface of the housing cover and opens in the upper direction and protrudes in the direction of the housing. A screw through-hole and a recess facing the first screw through-hole having a smaller diameter than the recess are provided, and the internal mount is provided with a second screw through-hole, and the recess is used for sealing. After the O-ring is received, a screw is screwed into the screw hole through the first screw through hole and the second screw through hole, and the O-ring is elastically deformed so that at least the recess is formed. A waterproof case configured to be in contact with the peripheral wall portion, the bottom portion, and the back side of the head of the screw can also be provided.

In the waterproof structure or waterproof case of the screw fixing portion, it is preferable that the depth of the recess is smaller than the height of the O-ring and the width of the recess is larger than the outer diameter of the O-ring. Further, it is preferable that the outer diameter of the back side of the head of the screw is larger than the width of the recess.

[0016]

FIG. 1 shows an example of parts of a waterproof case using a waterproof structure of a screw fixing portion of the present invention and an example of an assembling procedure. FIG. 2 shows a structure of a completed waterproof case. It is shown.

Reference numeral 10 denotes a housing constituting a waterproof case made of resin having a two-part structure. An outer peripheral groove 12 is formed at the end of the outer peripheral wall, and a packing 30 is accommodated in the outer peripheral groove 12. I have. On the other hand, a substantially hollow columnar insert nut fixing portion 14 is provided on the bottom surface 13 of the housing 10 perpendicular to the bottom surface 13. (Screw hole) 17 is fixed by insert molding.

At the tip of the outer peripheral wall of the storage cover 20 which forms a waterproof case together with the storage body 10, the outer peripheral groove 12 is formed.
Are provided. An opening is formed on the upper surface of the housing cover 20 in the direction of the upper surface so as to correspond to the insert nut 17.
A cylindrical recess 23 protruding in the 0 direction is provided. The first screw through hole 2 is formed in the bottom 24 of the recess 23.
6, and a recess 25 facing the first screw through hole 26 is formed around the first screw through hole 26. The recess 25 accommodates an O-ring 40 for sealing. The O-ring 40 has a hole having the same shape as the first screw through-hole 26, and is not particularly limited as long as it is made of a rubber-like elastic body.

The relationship between the size of the recess 25 and the size of the O-ring 40 is such that the recess depth A is smaller than the O-ring height A ', and the recess width B is smaller than the O-ring outer diameter B'. It is getting bigger. The outside diameter C of the screw 50 on the back side of the head 50a is:
It is larger than the recess width B. The screw 50 is provided with a washer. The dimensions of these recesses 25 and O-rings 40 are
The optimum value is determined based on the outer diameter of b, the dimensional value of the O-ring 40, the material and hardness of the rubber-like elastic body, and the like. Further, a second screw through-hole 61 is provided in the internal mount 60. The internal mount 60 is, for example, a printed circuit board on which electronic components and the like are mounted.

The assembly of the waterproof case is performed as follows. First, the packing 30 is placed in the outer peripheral groove 12 of the storage body 10, and the internal mounting is performed between the insert nut 17 provided in the storage body 10 and the first screw through hole 26 provided in the storage cover 20. A second screw through-hole 61 of the object 60 is arranged, and these are overlapped, and the outer peripheral groove portion 12 and the outer peripheral convex portion 22 are packed with the packing 30.
Are fitted to each other in a liquid-tight manner.

Next, the first screw through hole 26 of the recess 25 is formed.
O-ring 40 is arranged around the. In addition, screw 50
, The O-ring 40, the first screw through-hole 26, and the second screw through-hole 61 are inserted in this order, and finally screwed into the insert nut 17 provided in the housing 10. A screw fixing portion for fixing the housing cover 20, the internal package 60, and the housing 10 is configured.

FIG. 3 illustrates the operation of the O-ring 40 in the screw fixing portion. Hereinafter, description will be made with reference to FIGS. As shown in FIG. 3, since the recess width B of the recess 25 in which the O-ring 40 is accommodated is larger than the O-ring outer diameter B ′, when the screw 50 is not tightened, a difference between these differences is obtained. Only the peripheral wall 25 of this recess 25
A gap is formed between b and the outer peripheral surface of the O-ring 40. Further, since the depth A of the recess 25 in which the O-ring 40 is accommodated is smaller than the height A ′ of the O-ring, a part of the O-ring 40 projects from the opening of the recess 25. ing.

Next, when the screw portion 50b of the screw 50 is screwed into the insert nut 17 through the first screw through hole 26 and the second screw through hole 61, the back side of the head portion 50a of the screw 50 and O -The ring 40 comes in contact with this O-
The ring 40 is pressed toward the bottom 25 a of the recess 25, and its elastic deformation causes the peripheral wall 25 of the recess 25 to move.
It is deformed in the direction b and the direction of the base 50c of the screw 50. As a result, the O-ring 40 comes into contact with the back side of the head portion 50a of the screw 50, the bottom portion 25a and the peripheral wall portion 25b of the recess 25, and the base portion 50c of the screw 50, and further closely contacts these. In this way, the O-ring 40 comes into contact with the periphery of the first screw through hole 26, so that water can be prevented from entering the waterproof case from the first screw through hole 26, and a waterproof structure can be obtained.

At this time, the O-ring 40 should be in contact with at least three places: the back side of the head 50a of the screw 50, the bottom 25a of the recess 25, and the peripheral wall 25b. That is, when the O-ring 40 comes into contact with the peripheral wall 25b of the recess 25, the O-ring 40 is positioned, supported by the peripheral wall 25b, and sufficiently sealed at these three places. Further, the head 50 of the screw 50
a is larger than the recess width b of the recess 25, the screw 50 is inserted into the insert nut 1.
7, the back side peripheral portion of the head portion 50 a becomes the concave portion 2.
3, so that it cannot be further tightened. Therefore, the O-ring 40 is not crushed by the screw 50 being tightened more than necessary.

As described above, in the screw fixing portion and the waterproof case described above, the O-
The O-ring 40 is positioned by the contact of the ring 40, and is supported by the peripheral wall portion 25b. And this O-ring 40 is at least screw 5
The bottom of the head 50a, the bottom 25a of the recess 25, and the peripheral wall 25b are in contact with each other, and are sufficiently sealed at these three locations to ensure waterproofness around the first screw through hole 26. ing. At this time, in the above-mentioned waterproof case, since the O-ring 40 is also in contact with the base 50c of the screw 50, the O-ring 40 is more firmly sealed. Therefore, it is not necessary to use a special part such as a special processing screw, and the cost can be reduced.

Further, since the outer diameter of the back side of the head 50a of the screw 50 is larger than the recess width b of the recess 25, the screw 50 is tightened more than necessary,
-The ring 40 is not crushed. In addition, the storage body 10, the storage cover 20, and the internal package 60 are each composed of one screw 5.
Since it can be fixed by 0, space efficiency is good. Therefore, the case can be reduced in size and weight. Further, since the thickness of the side, top, and bottom surfaces of the waterproof case can be made substantially uniform, even in the case of a resin-made waterproof case, sink marks and the like having poor appearance are unlikely to occur, and the product yield can be improved. .

[0027]

As described above, in the screw fixing portion and the waterproof case of the present invention, the O-
The O-ring is positioned by the contact of the ring, and the O-ring is supported by the peripheral wall. The O-ring is in contact with at least the back side of the head of the screw, the bottom of the recess, and the peripheral wall, and is sufficiently sealed at these three places to ensure waterproofness around the first screw through hole. It has become. Therefore, it is not necessary to use a special part such as a special processing screw, and the cost can be reduced.

Further, since the outside diameter of the back side of the head of the screw is larger than the width of the recess, the O-ring may be crushed by tightening the screw more than necessary. There is no. Further, since the housing, the housing cover, and the internal package can be fixed with one screw, space efficiency is high. Therefore, the case can be reduced in size and weight. Further, since the thickness of the side, top, and bottom surfaces of the waterproof case can be made substantially uniform, even in the case of a resin-made waterproof case, sink marks and the like having poor appearance are unlikely to occur, and the product yield can be improved. .

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an example of components used for a waterproof structure of a screw fixing portion of the present invention and an assembling procedure.

FIG. 2 is a cross-sectional view illustrating an example of a structure of a screw fixing portion of the present invention.

FIG. 3 is a cross-sectional view illustrating an operation of an O-ring forming a waterproof structure in the screw fixing portion of the present invention.

FIG. 4 is a cross-sectional view showing an example of a structure of a waterproof case having a built-in conventional internal package.

FIG. 5 is a cross-sectional view showing another example of the structure of a waterproof case incorporating a conventional internal package.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Storage body 14 Insert nut fixing part 17 Insert nut (screw hole) 20 Storage cover 23 Concave part 24 Bottom part 25 Concave part 25a Bottom part 25b Peripheral wall part 26 First screw through hole 40 O-ring 50 Screw 50a Head part 50b Screw part 50c Base 60 Internal Mount 61 Second Screw Through Hole A Depth of Depth B Recess Width A 'O-Ring Height B' O-Ring Outer Diameter C Outer Diameter on Back Side of Screw Head

Claims (7)

[Claims] An article having a screw hole formed therein and another article having a screw through hole formed therein are fixed by screwing a screw into the screw hole through the screw through hole. In the portion, a recess facing the screw through hole is formed around the screw through hole, and an O-ring for sealing is housed in the recess, and a screw is screwed into the recess, and the O-ring has elasticity. A waterproof structure for the screw fixing part, wherein the screw fixing part is brought into contact with at least the peripheral wall part and the bottom part of the concave part and the back side of the head part of the screw by deformation. 2. The screw fixing device according to claim 1, wherein the depth of the recess is smaller than the height of the O-ring, and the width of the recess is larger than the outer diameter of the O-ring. Waterproof structure of the part. 3. The waterproof structure for a screw fixing part according to claim 1, wherein the outer diameter of the back side of the head of the screw is larger than the width of the recess. . 4. A housing and a housing cover, each of which is fitted to each other at the outer periphery thereof in a liquid-tight manner,
A waterproof case in which an internal package is attached, wherein a screw hole is formed in one of the storage body and the storage cover, and a first screw through hole is formed in the other. A second screw through-hole is provided in the internal mount, a recess facing the first screw through-hole is formed around the first screw through-hole, and an O- After storing the ring, a screw is screwed into the screw hole through the first screw through hole and the second screw through hole, and the O-ring is elastically deformed so that at least the peripheral wall portion of the recess is formed. A waterproof case characterized by being in contact with the bottom and the back side of the head of the screw. 5. A storage body and a storage cover body, which are fitted to each other at their outer peripheral portions in a liquid-tight manner,
A waterproof case in which an internal package is mounted, wherein a screw hole is formed in a bottom surface of the storage body, and an upper surface of the storage cover is opened in an upper surface direction, and the storage body direction is A recess is formed at the bottom of the recess, and a first screw through-hole is formed around the first screw through-hole, and a recess facing the first screw through-hole having a smaller diameter than the recess is formed around the first screw through-hole. A second screw through-hole is formed in the internal mount; an O-ring for sealing is accommodated in the recess; and the first screw through-hole and the second screw through-hole are formed. Wherein the O-ring is elastically deformed so that the O-ring contacts at least the peripheral wall and the bottom of the recess and the back side of the head of the screw. . 6. The waterproof case according to claim 4, wherein the depth of the recess is smaller than the height of the O-ring, and the width of the recess is larger than the outer diameter of the O-ring. Waterproof case. 7. The waterproof case according to claim 4, wherein the outer diameter of the screw on the back side of the head is larger than the width of the recess.