JP2000101265A - Water-proof structure of electric device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide water-proof structure of an electric device by which no highly accurate dimensional control is needed and the cost can be reduced. SOLUTION: This water-proof structure is provided with an electric circuit constituting an electric device, a case consisting of a first case and a second case 12 housing electric parts, etc., a water-proof packing which is inserted into the butted end face between the first and second cases, a notch part 13 which is formed adjacent to the butted end face of the second case so as to introduce a cable 14 from the outside into the case, and a bush 15 which has slightly larger than the notch part 13 and is formed integrally with the periphery of the cable and pressed into the notch part. In this case, the bush and notch part are formed facing the butted end face between the first and second cases, in all parts where both are in contact with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waterproof structure of an electric device which is provided with a waterproof property for an external cable introduction portion.

[0002]

2. Description of the Related Art Conventionally, in various electric appliances, a sealed case is used to secure the waterproofness of electric circuits and electric parts housed in the case, and cables for connection to the outside are used. There is known a waterproof structure in which an introduction portion is provided with waterproofness. As an electric device having such a waterproof structure, for example, a so-called GPS installed outdoors.
There is an antenna device for (global positioning system), for example, in which a planar antenna element and an electric circuit such as a low noise amplifier for amplifying a radio wave received by the antenna element are accommodated in a case, and an external signal processing is performed. They are connected to circuits and the like by cables.

[0003] Such an antenna device is configured, for example, as shown in FIG. That is, in FIG. 6, the antenna device 1 includes a case 2 and an antenna assembly 3 housed in the case 2. Case 2 above
Is composed of an upper case 4 and a lower case 5 formed by resin molding. The upper case 4 and the lower case 5 are combined with each other to define a sealed space inside. The lower case 5 includes a housing room 5a, and the antenna assembly 3 is provided in the housing room 5a.
Is to be incorporated. Further, the upper case 4 and the lower case 5 are provided with a flat annular waterproof packing 6 between the annular wall 4a and the seating surface 5b which are abutted against each other.
The waterproofness between the two can be ensured.

[0004] The antenna assembly 3 includes an antenna element 3
a, a circuit board 3b and a shield case 3c. The antenna element 3a is a planar antenna element and receives a radio wave from a GPS satellite. The circuit board 3b includes a low-noise amplifier and the like that detects and amplifies a radio wave received from the antenna element 3a, and an output signal of the circuit board 3b is sent to the outside via the antenna cable 7.

[0005] The antenna cable 7 is introduced into the case 2 by a waterproof structure as shown in FIG. In FIG. 7, a waterproof structure 8 is attached to a U-shaped notch 5d provided in the lower case 5 and a distal end portion 7a of an antenna cable 7 introduced into the case 2 and press-fitted into the notch 5d. And a bush 8a. The bush 8a is integrally formed with or fitted with the distal end portion 7a of the antenna cable 7 to be integrally formed. In this case, the outer shape of the bush 8a is formed in a U-shape according to the shape of the notch 5d, and the bush 8a is formed so as to be in close contact with the inner surface of the notch 5d by press-fitting.
It is formed slightly larger than the inner dimension of d. Further, when the upper case 4 and the lower case 5 are combined, the waterproof packing 6 is placed on the upper surface of the bush 8a, so that the bush 8a comes into close contact with the upper case 4. Thereby, the waterproofness by the waterproof structure 8 at the portion where the antenna cable 7 is introduced into the case 2 can be obtained.

[0006]

By the way, in the waterproof structure 8 having such a configuration, as shown in FIG. 8, the shapes of the bush 8a and the cutout 5d are U-shaped.
Area 8 extending along the press-fit direction on both sides of bush 8a
b, 8c. For this reason, the pressing force of the waterproof packing 6 by the combination of the upper case 4 and the lower case 5 acts on the lower region of the bush 8a.
No effect is exerted on the bush 8c, and the waterproof property on the peripheral surface of the bush 8a becomes uneven. Therefore, this region 8b,
In order to secure the waterproof property in 8c and make the waterproof property on the peripheral surface of the bush 8a uniform, it is necessary to increase the accuracy of the dimensional tolerance between the bush 8a and the notch 5d. As a result, strict control of the dimensions of the bush 8a and the cutout 5d is required, resulting in a problem that the cost is increased.

Furthermore, in the waterproof structure 8, since the waterproof boundary, that is, the contact portion between the bush 8a and the notch 5d is a surface, for example, as shown in FIG.
In the case where there is a step h between the upper surface 8d of the lower cover 5 and the seating surface 5b of the lower cover 5, even if the pressing force of the waterproof packing 6 is increased, the waterproof property at this step is reduced. Therefore, it is necessary to control the dimensions of the bush 8a and the notch 5d so as not to form such a step h, and there is a problem that the cost is similarly increased.

In view of the above, the present invention eliminates the need for high-precision dimensional control and can reduce the cost.
It is intended to provide a waterproof structure for electric equipment.

[0009]

According to the present invention, there is provided a case including a first case portion and a second case portion for accommodating an electric circuit, an electric component, and the like constituting an electric device; In order to introduce a cable from the outside into the case, a waterproof packing inserted into the butt end surface of the first case portion and the second case portion, and a butt end surface of the first case portion or the second case portion. A notch formed adjacently, and a bush having a shape slightly larger than the shape of the notch and integrally formed around the cable, and being pressed into the notch. In the waterproof structure of an electric device, the bush and the notch are formed so that all the portions that come into contact with each other face the butted end surfaces of the first case portion and the second case portion. Characterized in that it is, by a waterproof structure for an electric apparatus, is achieved.

[0010] The waterproof structure for electric equipment according to the present invention preferably further comprises a first groove formed in the butting end face of the first case portion or the second case portion so as to cross the notch. , So as to be continuous with the first groove,
A second groove formed in the bush, and a ridge formed on a butt end face of the second case portion or the first case portion so as to face the first groove and the second groove. ,
Contains.

According to the above configuration, since the waterproof boundary between the bush and the notch is opposed to the butted end face of the case, when the bush is press-fitted into the notch, the press-fitting is easily performed and the first press-fitting is performed. When the bush is pressed against the notch by the pressing force of the waterproof packing when the case portion and the second case portion abut against each other, all the portions that come into contact with the notch portion of the bush come into contact with the butting end surface of the case. Because they are facing
This contact portion contacts the cutout as a whole. Therefore, the pressing force of the waterproof packing acts uniformly on the entire contact portion of the bush, and uniform waterproofing on the peripheral surface of the bush can be obtained. In this case, since the accuracy of the dimensional tolerance of the surfaces of the bush and the notch that are in contact with each other does not have to be higher than in the past,
The dimensional control of the bush and notch does not have to be strict,
Manufacturing costs can be reduced.

Further, a first groove formed so as to cross the notch portion on the butted end surface of the first case portion or the second case portion, and the first groove is continuous with the first groove. A second groove formed in the bush, and a ridge formed on a butt end surface of the second case portion or the first case portion so as to face the first groove and the second groove, When the first case portion and the second case portion are abutted with each other, a part of the waterproof packing is formed by the ridge portion, so that the first groove and the second groove of the bush are formed. It is pushed into the groove and deforms. This allows
Since the edges of the first groove and the second groove are in line contact with the waterproof packing, the dimensional control of the bush and the notch is not strict, and a step is generated between the bush and the notch. In addition, high waterproofness can be obtained, and sufficient waterproofness can be achieved even if the pressing force applied between the first case portion and the second case portion is not so large.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings. FIG. 1 shows a first embodiment of a waterproof structure according to the present invention. In FIG. 1, a waterproof structure 10 is, for example, a part of the electric apparatus shown in FIG. 6, and is provided instead of the waterproof structure 8 shown in FIG. The waterproof structure 10 includes a U-shaped notch 13 provided in the lower case 12 with respect to a case including an upper case 11 and a lower case 12 which define a closed internal space.
And a bush 15 attached to the distal end portion 14a of the cable 14 to be introduced into the case and pressed into the cutout portion 13.

The bush 15 is integrally formed with the distal end portion 14a of the cable 14 by being integrally formed or fitted thereto. In this case, the outer shape of the bush 15 is formed according to the shape of the notch 13 and the bush 15 is press-fitted into the notch 13.
The notch 13 is formed slightly larger than the inner dimension thereof so as to be in close contact with the inner surface of the notch. Furthermore, this bush 15
When the upper case 11 and the lower case 12 are combined by sandwiching the waterproof packing 16 between their butted end surfaces, the waterproof packing 16 is placed on the upper surface of the bush 15 so that the upper case 11 is in close contact with the upper case 11. It is supposed to.

The above configuration is substantially the same as the conventional waterproof structure 8 shown in FIG. 7, but the waterproof structure 10 according to the embodiment of the present invention is different in the following points. That is, as shown in detail in FIG.
3 and the bush 15 are formed so that their shapes are opposed to the butted end faces of the upper case 11 and the lower case 12, that is, there is no portion that is perpendicular or opposite to the butted end faces. Have been. In the illustrated case, the cutout 13 and the bush 15 are composed of a central cylindrical portion 13a and inclined planes 13b and 13c on both sides.

The waterproof structure 10 according to the embodiment of the present invention is configured as described above.
3, when the upper case 11 and the lower case 12 abut against each other, the pressing force is applied to the waterproof packing 16.
And acts on the upper surface of the bush 15. As a result, the bush 15 is pressed into the cutout 13. At this time, the shape of the bush 15 is such that all contact portions with the notch 13 are formed so as to face the butted end surfaces of the upper case 11 and the lower case 12, that is, toward the upper surface. Part 1
3 can be easily press-fitted, and assemblability is improved. Further, in the contact portion of the bush 15 with the notch 13, as shown by the arrow in FIG. 2, the component force in the normal direction of the pressing force acts on all the contact portions, so that the notch 13 is Will be pressed.

As a result, substantially uniform waterproofness can be obtained between the bush 15 and the notch 13 at all the contact portions. Therefore, since the dimensional tolerance of the bush 15 and the notch 13 does not need to be higher precision than in the past, the dimensional control of the bush 15 and the notch 13 does not need to be very strict. Thus, the manufacturing cost of the bush 15 and the notch 13 can be reduced.

FIG. 3 shows a second embodiment of the waterproof structure according to the present invention. In FIG. 3, the waterproof structure 20 is
The structure is almost the same as the waterproof structure 10 shown in FIG.
The configuration is different in the following points. That is, the waterproof structure 2
0 is a first groove 21 formed so as to cross the notch 13 at the abutting end surface of the lower case 12, ie, the upper surface 12a, and an upper surface 15d of the bush 15 so as to be continuous with the first groove 21. And a ridge 23 formed on the butt end face of the upper case 11 so as to face the grooves 21 and 22.

The first groove 21 is formed deeper than the depth of the notch 13, but the second groove 22 is formed shallower than the first groove 21. The ridge 23
Are formed so as to become thinner toward the front end, and the thickness thereof is set smaller than the width of the grooves 21 and 22.

According to the waterproof structure 20 having such a structure,
As shown in FIG. 4, when the bush 15 is pressed into the cutout 13 of the lower case 12, the first groove 21 and the second groove 22 are formed on the upper surface 12 a of the lower case 12 and the upper surface 15 d of the bush 15. It looks like a single continuous groove. Then, the waterproof packing 16 is placed on the groove, and the upper case 11 is further placed on the groove. When the upper case 11 is pressed downward, as shown in FIG.
Is deformed so that a part thereof enters the grooves 21 and 22.
In this case, the deformation of the waterproof packing 16 appears more remarkably because the tip of the ridge portion 23 is thin.

Therefore, in the waterproof structure 20, as in the case of the waterproof structure 10 shown in FIG. 1, the shape of the bush 15 is such that all the contact portions with the notches 13 are formed by the upper case 11 and the lower case 12. The butt end surface, that is, the upper surface is formed so as to face toward the upper surface, so that the bush 15 can be easily pressed into the notch portion 13 and at the contact portion of the bush 15 with the notch portion 13. As shown by arrows in FIG. 2, the notch 13 is pressed by the component force in the normal direction of the pressing force acting on all surfaces and line contact portions. Thereby, substantially uniform waterproofness can be obtained between the bush 15 and the notch 13 on all surfaces and line contact portions.

Further, as described above, the waterproof packing 16 deformed by the ridges 23 comes into line contact with the edges of the grooves 21 and 22, whereby the shapes of the grooves 21 and 22 are deformed and the waterproof packing 16 is in contact with the waterproof packing. Matching is improved, and even if the notch 13 of the lower case 12 and the bush 15 are not strictly controlled, and even if a step occurs as shown in FIG. 9, waterproofness can be reliably obtained. In this case, upper case 1
The pressing force for deforming the waterproof packing 16 by combining the first and lower cases 12 may be smaller than when the waterproof packing 16 is compressed in a flat state. Further, since the first groove 21 is formed deeper than the notch 13, when the bush 15 is pressed into the notch 13, the side surface of the bush 15 is elastically connected to the edge of the first groove 21. The lower case 12
And the bush 15 can be assured of waterproofness.

In the above embodiment, the notch 13 is provided in the lower case 12, but it is not limited to this, and it is apparent that the notch 13 may be provided in the upper case 11. In each of the above embodiments, the case is divided into upper case 11 and lower case 1 by a horizontal division line.
Although it is divided into two, the present invention is not limited to this, and it is apparent that the present invention can be applied to a case where the division is made by a vertical division line or an oblique division line.

[0024]

As described above, according to the present invention, since the waterproof boundary between the bush and the cutout is opposed to the butted end face of the case, when the bush is press-fitted into the cutout, the press-fitting is not performed. When the bush is pressed against the notch by the pressing force of the waterproof packing when the first case portion and the second case portion are abutted with each other, all contact with the notch portion of the bush is performed. Is opposed to the butted end face of the case, so that the contact portion as a whole comes into contact with the notch. Therefore, the pressing force of the waterproof packing acts uniformly on the entire contact portion of the bush, and uniform waterproofing on the peripheral surface of the bush can be obtained. In this case, since the precision of the dimensional tolerance of the surfaces of the bush and the notch that are in contact with each other does not have to be higher than in the past, the dimensional control of the bush and the notch does not have to be strict, and the manufacturing cost is lower. Could be reduced.

Further, the first case portion or the second case portion is provided with a first groove formed so as to cross the notch portion on the butt end face of the second case portion and the first groove portion so as to be continuous with the first groove portion. A second groove formed in the bush, and a ridge formed on a butt end surface of the second case portion or the first case portion so as to face the first groove and the second groove, When the first case portion and the second case portion are abutted with each other, a part of the waterproof packing is formed by the ridge portion, so that the first groove and the second groove of the bush are formed. It is pushed into the groove and deforms. This allows
Since the edges of the first groove and the second groove are in line contact with the waterproof packing, the dimensional control of the bush and the notch is not strict, and a step is generated between the bush and the notch. In addition, high waterproofness can be obtained, and sufficient waterproofness can be achieved even if the pressing force applied between the first case portion and the second case portion is not so large.

Thus, according to the present invention, high-precision dimensional control is not required, and the cost can be reduced.
An extremely excellent waterproof structure for electric equipment can be provided.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a first embodiment of a waterproof structure of an electric device according to the present invention.

FIG. 2 is a schematic front view of the waterproof structure of FIG.

FIG. 3 is an exploded perspective view showing a second embodiment of the waterproof structure of the electric device according to the present invention.

FIG. 4 is a schematic perspective view showing a state where the waterproof structure of FIG. 3 is partially assembled.

5 is a sectional view of the waterproof structure of FIG. 3 after assembly.

FIG. 6 is a schematic cross-sectional view illustrating an example of a conventional electric device having a waterproof structure.

FIG. 7 is an exploded perspective view showing an example of a conventional waterproof structure.

8 is a schematic front view of the waterproof structure of FIG.

FIG. 9 is a front view illustrating a step in the waterproof structure of FIG. 7;

[Explanation of symbols]

 10, 20 Waterproof structure of electrical equipment 11 Upper case (first case part) 12 Lower case (second case part) 13 Notch part 14 Cable 15 Bush 16 Waterproof packing 21 First groove 22 Second groove 23 Protrusion Strip

Claims (2)

[Claims] 1. A case comprising a first case portion and a second case portion for accommodating an electric circuit, an electric component and the like constituting an electric device, and an abutting end face of the first case portion and the second case portion. A notch formed adjacent to a butt end face of the first case portion or the second case portion for introducing a cable from the outside into the case; A bush that has a shape slightly larger than the shape and is integrally formed around the cable and that is press-fitted into the notch; Are formed so as to face the butted end faces of the first case portion and the second case portion in all the portions that come into contact with each other, Water structure. A first groove formed on the butted end face of the first case portion or the second case portion so as to cross the notch; and a continuation of the first groove. A second groove formed in the bush, and a ridge formed on a butt end surface of the second case portion or the first case portion so as to face the first groove and the second groove. The waterproof structure for an electric device according to claim 1, comprising: