JPH0731589Y2 - Waterproof structure - Google Patents

Description

Detailed Description of the Invention Outline An electronic device or the like is housed in a casing, and the peripheral edge of the opening of the casing is fitted into a recess of an elastic base, thus waterproofing the inside of the casing. In the base, a sealing ridge is provided upright inside the peripheral wall defining the recess, and the sealing ridge presses against the peripheral edge of the opening of the casing to hermetically seal the inside of the casing. Further, a water drain hole communicating with the outside is formed in the groove formed by the peripheral wall and the sealing ridge.

As a result, the water that has entered through the gap between the casing and the base is smoothly drained, and the airtightness inside the casing is enhanced.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waterproof structure for electronic devices and the like, and more particularly to a structure for waterproofing electronic devices from a high-pressure water stream.

2. Related Art FIG. 6 is a sectional view of a typical prior art raindrop sensor 1. This raindrop sensor 1 is attached to a vehicle body such as a bonnet and detects the amount of rainfall. Based on the detected rainfall amount, for example, the wiper wiping interval is controlled.

The substrate 2 on which electronic components for detecting the amount of rainfall are mounted is housed in a rigid casing 3 made of resin or the like, and an opening 4 of the casing 3 has a base 5 made of an elastic material such as rubber. It is fitted in the recess 6 of. The recess 6
An annular protrusion 7 is formed on the inner periphery of the peripheral wall 8 of the base 5 that forms the base. The annular protrusion 7 contacts the peripheral edge of the opening 4 of the casing 3. A peripheral wall 8 that forms the protrusion 7 and the recess 6
And the opening 4 of the casing 3 allows the casing 3
The inside is kept airtight.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention Although the above-mentioned conventional technique can obtain a so-called drip-proof effect against raindrops and the like, it cannot obtain a waterproof effect against a water flow that causes water pressure during car wash. That is, as shown by reference numeral 9 in FIG.
Since there is no drainage hole in the groove 10 formed by the peripheral wall 8 and the peripheral wall 8, water that has entered the groove 10 will enter the casing 3 beyond the ridge 7.

An object of the present invention is to provide a waterproof structure capable of obtaining a reliable waterproofing effect even for a water flow under pressure.

Means for Solving the Problems The present invention provides a structure for waterproofing the inside of a casing by fitting an opening peripheral portion that defines the opening of a casing having an opening into a recess formed in an elastic base. A first sealing ridge, which is erected on the outside in a slanted manner over the entire circumference in an inclined manner, and whose upper portion is in pressure contact with the opening peripheral edge portion of the casing; and inside the first sealing ridge in the recess. A second sealing ridge that is erected over the entire circumference and is in close contact with the inner peripheral surface of the casing, and a drain hole communicating with the outside outside the first sealing ridge in the recess are formed. It is a waterproof structure characterized by.

Further, the present invention is characterized in that the water drainage hole communicates with the base in a vertical direction, and the communicating lower end portion is connected to a side groove extending laterally of the base and communicating with the outside. To do.

According to the present invention, the base made of an elastic material is formed with a recess inside the peripheral wall, and the sealing ridge is doubled inside the peripheral edge defining the recess. There is. A water drain hole communicating with the outside is formed in the concave groove between the peripheral wall and the outer first sealing ridge. In the base thus formed, the peripheral edge portion of the opening of the casing is fitted in the recess. Therefore, the water that has entered through the gap between the peripheral wall and the peripheral portion of the casing is drained from the groove through the drain hole. Further, the first sealing ridges are formed to be inclined outward, and as a result, the first sealing ridges have a higher pressure contacting force with which the first sealing ridges come into pressure contact with the peripheral edge of the opening of the casing.
Prevents water from entering from the outside. A small amount of water that has entered beyond the first sealing ridge can be completely prevented by the inner second sealing ridge, and the inside of the casing can be reliably waterproofed.

Further, according to the present invention, the drainage hole is communicated, for example, in a vertical direction of the base, and the communicating lower end portion is connected to a side groove that is formed to extend laterally of the base and communicates with the outside. By this, the water having a water pressure can be smoothly drained.

Embodiment FIG. 1 is a sectional view of a raindrop sensor 11 according to an embodiment of the present invention, and FIG. 2 is a perspective view of the raindrop sensor 11 as a whole.
The raindrop sensor 11 is attached to, for example, a vehicle body such as a bonnet or a front grill. Casing 12
Inside, a pair of a light emitting element 13 and a light receiving element 14 are mounted so as to face each other, and raindrops block the optical path 15 formed by these elements 13 and 14, thereby increasing the amount of rainfall. Can be detected. The wiper wiping interval and the like are controlled based on the detection result.

The raindrop sensor 11 generally includes a casing 12 and the element.
Board 16 on which 13, 14 and other electronic components are mounted, and base 17
Composed of and.

FIG. 3 is a perspective view of the base 17 viewed from above, and FIG. 4 is a perspective view viewed from the bottom side. The base 17 is made of an elastic material such as rubber, and has a plate-shaped portion 21, a peripheral wall 22 formed upright on the peripheral portion of the plate-shaped portion 21, and an annular first inner wall of the peripheral wall 22. The first sealing ridge 23 and the second sealing ridge 24 are included. The board 16 is provided in the second sealing ridge 24 of the plate-shaped portion.
A groove 25 is provided between the peripheral wall 22 and the first sealing protrusion 23, and a plurality of drain holes 26 are formed in the groove 25.

FIG. 5 is an enlarged sectional view showing the vicinity of the drain hole 26 in a state where the casing 12 is fitted in the base 17. Drainage hole
Reference numeral 26 is formed so as to penetrate in the vertical direction of FIG. 5, that is, in the thickness direction of the plate-like portion 21, and the lower end portion thereof is connected to the side groove 27 formed to extend laterally of the base 17, and thus the concave groove 25 Drainage hole 26
And it communicates with the outside through the side groove 27. The drain hole 26 is
The raindrop sensor 11 is provided on the front side, which is in a low position when it is attached to the vehicle body. Therefore, the width W and the depth H of the gutter 27 are selected to a size that does not cause reverse flow of water during car washing. Be done.

The casing 12 is made of a rigid material such as polycarbonate and has an opening 31 in which an outwardly extending flange is formed.
32 are formed. Corresponding to this, the peripheral wall 22 of the base 17
Is formed in a tapered shape, and a ridge 33 is formed on the inner peripheral surface at the tip of the peripheral wall 22. Therefore, when the opening 31 of the casing 12 is fitted in the recess 20 of the base 17, the flange 32 is locked by the tapered peripheral wall 22 and the protrusion 33, and thus the retaining is performed.

The first sealing protrusion 23 is formed to be inclined outward,
When the casing 12 is fitted into the base 17, the first sealing ridge 23 presses against the front end face 31a of the opening 31, thereby holding the flange 32 together with the peripheral wall 22 and the ridge 33 without rattling. To do. At this time, the outer peripheral surface of the second sealing projection 24 is in close contact with the inner peripheral surface of the opening 31.

In the raindrop sensor 11 configured as described above, the water transmitted along the outer peripheral surface of the casing 12 is the casing 12 and the peripheral wall 22.
Due to the close contact with, the entry into the casing 12 is prevented. When the water pressure becomes high and water invades from between the peripheral wall 22 and the casing 12, the invaded water follows the concave groove 25,
As indicated by reference numeral 30 in FIG. 5, the water is discharged from the drain hole 26 through the side groove 27.

When the water pressure is further increased, the first sealing ridge 23 is urged by the water flow in the direction in which the first sealing ridge 23 is pressed against the front end surface 31a of the opening 31, and thus the inside of the casing 12 is kept airtight even against the high water pressure. can do. Further, even if a small amount of water enters from between the first sealing ridge 23 and the front end surface 31a of the opening 31, the second sealing ridge 24 prevents water from entering the casing 12. Can be prevented. This allows the substrate
Electronic components such as 16 and elements 13 and 14 mounted on the substrate 16 can be reliably waterproofed.

As described above, according to the present invention, the peripheral edge of the opening of the casing is fitted into the recess of the elastic base, and the first and second sealing ridges are provided inside the recess of the base. Double standing,
The outer first sealing ridge is erected so as to be inclined to the outside, and the upper portion is pressed against the opening peripheral edge portion of the casing, and the inner second sealing ridge is closely attached to the inner peripheral surface of the casing. Since a water drain hole communicating with the outside is formed in the concave groove formed upright and formed between the peripheral wall and the first sealing ridge, even with respect to water flow under pressure, The water can be discharged from the drain hole, and the water flow presses and urges the first sealing ridge, so that the inside of the casing can be kept airtight, and a small amount of water should be discharged between the first sealing ridge and the peripheral edge of the opening of the casing. Even if
The inside of the casing can be reliably waterproofed by the second sealing ridges that are in close contact with the inner peripheral surface of the casing.

[Brief description of drawings]

1 is a sectional view of a raindrop sensor 11 according to an embodiment of the present invention, FIG. 2 is a perspective view of the raindrop sensor 11, FIG. 3 is a perspective view of a base 17 seen from above, and FIG. 4 is a base. FIG. 5 is a perspective view of the bottom 17 viewed from the bottom side, FIG. 5 is an enlarged sectional view showing the peripheral wall 22 of the base 17 and the vicinity of the opening 31 of the casing 12, and FIG. 6 is a sectional view of the raindrop sensor 1 of the prior art. FIG. 7 is an enlarged sectional view showing the peripheral wall 8 of the base 5 and the vicinity of the opening 4 of the casing 3. 11 ... Raindrop sensor, 12 ... Casing, 16 ... Substrate, 17 ... Base, 20 ... Recess, 22 ... Peripheral wall, 23 ... First sealing ridge, 24 ... Second
Sealing ridge, 25 ... concave groove, 26 ... drainage hole, 27 ... gutter, 31 ... opening, 32 ... flange

Claims (2)

[Scope of utility model registration request] 1. A structure for waterproofing the inside of a casing by fitting an opening peripheral portion for defining the opening of a casing having an opening into a recess formed in an elastic base, wherein the entire circumference is within the recess. A first sealing ridge, which is erected in a slanted manner to the outside, the upper part of which is in pressure contact with the peripheral edge of the opening of the casing, and is erected over the entire circumference inside the first sealing ridge in the recess. A second sealing ridge that is provided and is in close contact with the inner peripheral surface of the casing, and a drain hole that communicates with the outside are formed outside the first sealing ridge in the recess. Waterproof structure. 2. The water drain hole connects the base in a vertical direction,
The waterproof structure according to claim 1, wherein the communicating lower end portion is connected to a side groove that is formed to extend laterally of the base and communicates with the outside.