JP3746893B2 - Waterproof cover for electronic parts - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a drip-proof (waterproof) electronic component waterproof cover used for interior of an in-vehicle electronic component such as an engine control module, and in particular, ventilation for maintaining the balance of atmospheric pressure inside and outside the cover. The present invention relates to a waterproof cover such as an electronic component configured so that the waterproofness and dustproofness in the waterproof cover can be enhanced.
[0002]
[Prior art]
An electronic component waterproof cover installed in a space called an air box formed between an engine room and a vehicle compartment of an automobile and used for waterproofing electronic components such as a vehicle computer. As a prior example of the electronic component waterproof cover, there is a structure as shown in FIGS. That is, the waterproof cover such as an electronic component which is the preceding example is composed of a resin lower cover 1 whose upper surface is open and a resin upper cover 2 whose lower surface is open. The detailed structure of the lower cover 1 is as follows. The inside is formed in a storage portion 1A for storing an electronic component (not shown) (electronic device or the like), and a cylindrical portion 1B having an upper surface opening having an upper and lower shaft center is formed in the storage portion 1A. In this cylindrical portion 1B, as shown in FIG. 3, a conical cylindrical portion 1C whose outer diameter gradually decreases downward from the opening surface of the upper surface is integrally formed, and the central axial line of the cylindrical cylindrical portion 1C is formed. A vent hole 1D is formed along.
[0003]
Further, a locking shaft portion 1E for connecting the upper cover 2 is formed on the back side of the lower cover 1, and the locking claws of the upper cover 1 are provided at a plurality of positions on the side opposite to the back surface side having the locking shaft portion 1E. The piece 1F is integrally formed. 1G is a substantially semicircular harness insertion groove for guiding a wire harness (not shown) drawn from an electronic component (not shown) in a watertight manner in cooperation with a grommet attached to the wire harness. The bracket used in order to fix to the vehicle body in the space called the air box formed between the engine room and the vehicle interior is shown.
[0004]
The detailed structure of the upper cover 2 is such that the upper surface opening periphery of the lower cover 1 has a peripheral groove 2A inserted through the waterproof packing 3, and the above-described locking shaft portion is provided on the back side of the upper cover 2. An engagement piece 2B that engages with 1E is formed integrally. A plurality of locking frames 2C are formed on the side opposite to the back side having the engaging piece 2B to lock the upper cover 2 and the lower cover 1 by locking with the locking claw piece 1F. ing. Note that 2D is a substantially semicircular harness insertion groove that forms a circular wire harness insertion hole in cooperation with the harness insertion groove 1G, and 2E is connected to the lower cover 1 through the waterproof packing 3 in a watertight state. The attachment screw insertion hole for making it maintain is shown.
[0005]
Thus, in the lower cover 1 of the waterproof cover such as an electronic component as the preceding example, the vent hole 1D penetrating the inside and the outside of the lower cover is provided. The reason why this vent hole 1D is provided is that when the lower cover 1 and the upper cover 2 for storing electronic parts and the like are attached in a watertight manner via the waterproof packing 3 and are used on a vehicle body or the like, for example, the climate Changes in air pressure occur repeatedly in a sealed waterproof cover due to temperature changes accompanying changes in temperature, or changes in the heat generation temperature of electronic components when the electronic components are operating or not operating, especially in the waterproof covers. When the temperature becomes high, the pressure in the waterproof cover is abnormally increased, which causes adverse effects such as deformation of the waterproof cover and malfunction of electronic components. Therefore, as a means for preventing the adverse effect, the vent hole 1D is provided, and when the internal pressure (atmospheric pressure) of the sealed waterproof cover is increased, the vent hole 1D is discharged. Further, when the internal pressure of the waterproof cover is reduced (at the time of negative pressure), it is devised so that the outside air can be sucked from the vent hole 1D so that the balance of the atmospheric pressure inside and outside the cover is maintained.
[0006]
[Problems to be solved by the invention]
However, in a waterproof cover such as an electronic component provided with the vent hole 1D, there is a problem that water droplets (moisture) enter the waterproof cover through the vent hole 1D. In other words, the outer shape of the conical cylinder portion 1C provided to form the vent hole 1D is formed in an inverted conical shape that is pointed downward in order to suppress the intrusion of moisture from the outside of the cover. By adopting this inverted conical shape, for example, when moisture at the time of car washing or the like adheres to the outer wall surface of the conical cylinder portion 1C, the moisture travels along the outer peripheral surface of the conical cylinder portion, and at the tip end portion outside the conical cylinder portion, It becomes the collar 4 positioned so as to close the lower end of the air vent 1D. There is no problem when the heel 4 is dropped from the tip, but when the inside of the waterproof cover such as an electronic component becomes negative pressure when the heel 4 is attached to the tip, the heel 4 attached to the tip. Is sucked into the waterproof cover through the vent hole 1D, and this causes a problem that the waterproofness inside the waterproof cover is impaired. Further, the vent hole 1D structure has a problem that dust outside the waterproof cover is easily sucked into the waterproof cover due to an intake action into the waterproof cover when the waterproof cover is under negative pressure.
[0007]
The present invention has been made paying attention to such inconvenience, and even if a crease exists at the outer tip of the inverted conical cylinder part for forming a vent hole to be provided in the lower cover, the crease is sucked into the waterproof cover. The air intake hole is opened at a position where it does not occur to improve the waterproofness in the case, and the upper cover is provided with a cylindrical wall that restricts the flow of air drawn from the air intake hole provided in the lower cover. An object of the present invention is to provide a waterproof cover such as an electronic component that is excellent in waterproofness and dustproofness by allowing dust contained therein to be prevented from entering the waterproof cover with the cylindrical wall.
[0008]
[Means for solving the problems]
In order to achieve the first object, the present invention provides a cover internal space constituted by a combination of a resin lower cover (11) whose upper surface opens and a resin upper cover (12) whose lower surface opens. In a waterproof cover such as an electronic component that allows ventilation between the inside and outside of the cover when the internal pressure changes, and maintains the balance between the cover internal pressure and the external pressure, the lower cover (11) has a vertical axis. And a conical cylinder wall surface excluding the sharp end (18) portion of the conical cylinder wall (17) in the opposite direction, forming an inverted conical cylinder wall (17) having an upper end opened and a lower end pointed In the position, a vent hole (19) without an undercut passing vertically through the inside and outside of the lower cover is drilled , and the upper cover (12) is covered with the lower cover (11) inside the upper cover (12). When wearing The upper opening of the concave of the reverse tapered tubular wall (17) that was allowed projecting tubular wall (20) extending vertically downward from said upper cover (12) which is loosely fitted in (16A) It is characterized by a waterproof cover for the electronic parts and the like.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in detail below based on the embodiments shown in the drawings. The overall structure of the electronic component waterproof cover according to the present embodiment is the same as that of the waterproof cover such as the electronic component shown in FIG. Since the overall structure is substantially the same, the description of the overall structure of the present embodiment is omitted, and the main structure of the present invention will be described with reference to FIG.
[0011]
Reference numeral 11 denotes a resin lower cover for storing an electronic component (not shown), and 12 denotes a resin upper cover corresponding to the lower cover. The outer assembly of the lower cover 11 and the upper cover 12 is a preceding example. 2 is substantially the same as the outer shape of FIG. 2 described above, the lower cover 11 has an upper surface opened, the upper cover 12 has a lower surface opened, and both the covers 11 and 12 are connected to the upper cover 12. It has a structure in which it is water-tightly attached via a waterproof packing 14 inserted in a packing insertion groove 13 formed on the back side.
[0012]
Inside the lower cover 11, a vertical cylinder portion 16 is formed so as to approach the back wall surface 15 and penetrate the inside and outside of the lower cover 11, and the upper end is opened inside the cylinder portion 16. An inverted conical cylinder wall 17 whose lower end is a sharp tip 18 is formed integrally with the lower cover 11. And the ventilation hole 19 which penetrates the inside and outside of a lower cover is drilled in the cone wall surface position except the said sharp tip 18 part of this reverse direction cone cylinder wall.
[0013]
Next, the structure of the upper cover 12 will be described. Inside the upper cover 12, when the upper cover 12 is attached to the lower cover 11 via the waterproof packing 14, the upper cover 12 is formed on the lower cover 11. A cylindrical cylindrical wall 20 that is loosely fitted through an appropriate gap (C) is projected from the upper opening 16A of the cylindrical portion 16.
[0014]
Since the adherend coupling structure between the lower cover 11 and the upper cover 12 having the above-described structure is equivalent to the electronic component waterproof cover described in the preceding example, description of the adherend coupling structure of the lower and upper covers is omitted.
[0015]
Next, the operation of the waterproof cover such as the electronic component will be described. The lower cover 11 is formed with a reverse conical cylindrical wall 17 and the conical cylindrical wall surface excluding the tip 18 of the reverse conical cylindrical wall 17. Since the vent hole 19 penetrating the inner and outer sides of the lower cover 11 is formed at a position, moisture (water droplets) adhering to the outer peripheral surface or inner peripheral surface of the conical cylinder wall 17 in the reverse direction is temporarily removed from the conical cylinder wall 17. Even if the heel 4 descends along the wall surface and the ridge 4 is generated at the tip 18 of the conical cylinder wall, the ridge 4 is generated at a position away from the opening of the vent hole 19. Even if a negative pressure is generated inside the air hole 19 and air is sucked into the air vent 19, the air bag 4 is not sucked into the electronic component waterproof cover by the air intake. It is done.
[0016]
Further, when the lower cover 11 and the upper cover 12 are attached via the waterproof packing 14, the lower cover 11 and the upper cover 12 protrude from the upper cover 12 inside the upper opening 16 </ b> A of the cylindrical portion 16 provided in the lower cover 11. Since the cylindrical wall 20 is loosely fitted through a slight gap (C), the cylindrical wall 20 is a baffle member that regulates the flow of dust contained in the air flowing through the upper opening 16A. Thus, it is difficult for dust to enter the electronic component waterproof cover, and a waterproof cover such as an electronic component having excellent dust resistance can be obtained.
[0017]
【The invention's effect】
As described above, according to the electronic component waterproof cover of the present invention, for example, while maintaining sufficient air flow between the inside and outside of the waterproof cover due to a change in the internal pressure inside the resin waterproof cover that accommodates electronic components and the like, The waterproofness and dustproofness of electronic parts and the like that are installed inside the cover are improved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an essential part showing an embodiment of a waterproof cover for electronic parts and the like according to the present invention.
FIG. 2 is an exploded perspective view showing the overall structure of a waterproof cover such as an electronic component.
FIG. 3 is a cross-sectional view of a main part showing a waterproof cover for a conventional electronic component or the like.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 ... Lower cover 12 ... Upper cover 13 ... Packing insertion groove 14 ... Waterproof packing 15 ... Back wall 16 ... Cylindrical part 16A ... Upper side opening part 17 ... Conical cylindrical wall 18 ... Point 19 ... Vent hole 20 ... Cylindrical wall

Claims (1)

When the internal pressure changes in the internal space of the cover formed by the combination of the resin lower cover (11) whose upper surface is open and the resin upper cover (12) whose lower surface is open, ventilation between the inside and outside of the cover is performed. In the waterproof cover for electronic parts and the like configured to maintain a balance between the cover internal pressure and the external pressure, the lower cover (11) has a vertical axis, an upper end opened, and a lower end pointed. An undercut that forms a conical cylinder wall (17) in the opposite direction and penetrates the inner and outer sides of the lower cover in a vertical direction at a conical cylinder wall surface position excluding the tip (18) portion of the opposite conical cylinder wall (17). When the upper cover (12) is attached to the lower cover (11) on the inner side of the upper cover (12), the conical cylindrical wall (17) in the reverse direction is formed. On the concave Waterproof cover such as an electronic component for opening from the upper cover (12) which is loosely fitted in (16A), characterized in that allowed projecting tubular wall (20) extending vertically downward.

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