JPH0611565Y2 - Waterproof sealing structure of electric box - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a waterproof sealing structure for an electric box having a structure in which a printed circuit board is assembled.

[Problems to be Solved by Prior Art and Invention] In general, an electric box of this kind is provided with a printed circuit board in which a member device such as an integrated circuit or an electric component which requires high waterproofness is incorporated. . By the way, in this case, there is a risk that water such as rainwater may enter through the through hole formed in the electric box, and thus it is necessary to ensure the sealing of the through hole portion. Therefore, conventionally, a lead wire lead-out portion of a rubber grommet for inserting a lead wire fitted in a through hole formed in an electric box and a through hole fitting portion of the grommet are sealed with a sealant (water). It was designed to prevent the intrusion of. In this case, however, the sealant
Since the adhesive was simply applied to the grommet, the lead wire, and even the outer peripheral surface of the electric box, the adhesive of the sealant was not sufficient, and the adhesive of the sealant was not adhered due to vibration or aging. There is a fear that it will be impaired and the preventive property will decrease, which is a problem.

[Means for Solving the Problems] The present invention has been conceived in view of the above circumstances, and was devised with the object of providing a waterproof sealing structure for an electric box that can eliminate these drawbacks. In order to wire a lead wire through a through hole of an electric box for mounting a structure on a printed circuit board to be assembled to a body, the through hole is formed into a cylindrical shape by bending its peripheral portion so as to enter the box. , In the electric box, a cylindrical retainer having an inner cylindrical surface having a diameter larger than that of the cylindrical through hole,
The one end side is arranged so that the inner cylindrical surface surrounds the cylindrical through hole and is applied to the inner surface of the electric box, and the other end side is applied to the structural body side. It is characterized in that it is passed through and sealed with a sealing agent.

Further, the present invention is capable of reliably preventing the intrusion of water from the lead wire penetrating portion of the electric box by this structure.

[Embodiment] Next, an embodiment of the present invention will be described with reference to the drawings. In the drawings, reference numeral 1 denotes an electric box, and the electric box 1 includes a lid body 2 in which an upper surface and four side surfaces are integrally formed,
It is formed in a box shape with a bottom body 3 that closes the lid body 2 from below, a packing 1a is interposed between the peripheral edges of the lid body 2 and the bottom body 3 facing each other, and a stopper member 4 is provided. It is fixed in a sealed manner.

On the other hand, 5 is a structure integrally fixed to the upper surface of the bottom body 3, and the printed circuit board 6 is integrally assembled on the upper part of the structure. Further, an electric component 8 such as an integrated circuit or a diode is incorporated in the structure 5 and the printed board 6.

Further, the bottom body 3 has through holes 3 for wiring the lead wires 9.
Although a is provided, the through hole 3a is formed into a tubular shape by bending upward so that the peripheral edge portion is inserted into the box. Reference numeral 10 denotes a retainer made of a rubber elastic material, and the retainer 10 has a cylindrical shape with a bottom whose upper surface is closed and whose lower side is opened in the first embodiment shown in FIG. The diameter of the cylindrical surface is set to be larger than the outer diameter of the cylindrical through hole 3a, and the retainer 10
The end portion on the opening side is configured to be applied to the upper surface of the bottom body 3 in a state where there is a gap in the cylindrical through hole 3a. Further, the outer peripheral surface of the ceiling portion of the retainer 10 is cut out in a step shape to form an engaging portion 10a, and the engaging portion 10a is fitted into an engaging hole 5a formed on the structure 5 side to stop the engaging portion 10a. It is getting worn. Moreover, the lead wire 9 wired from the outside is configured to be wired in the box through the through hole 3a, the ceiling portion of the retainer 10 and connected to the printed circuit board 6. In this state, the cylindrical portion of the retainer 10 is filled with a curable sealant A such as an epoxy resin or a photocurable resin, thereby forming a water sealing structure.

In the embodiment of the present invention constructed as described above, the lead wire 9 is wired in the box through the through hole 3a of the electric box 1, but the through hole 3a is formed in a cylindrical shape toward the inside. The lead wire 9 is wired through the sealant A filled so as to dig in here.

That is, in the present invention, by surrounding the cylindrical through hole 3a with the retainer 10 having an inner cylindrical surface larger than this,
A gap is formed between the retainer 10 and the cylindrical through hole 3a, and this gap is also filled with the sealing agent A. Therefore, the cylindrical through hole 3a bites into the sealing agent A. Becomes As a result, the adhesive performance of the sealant A is enhanced and the sealant A is firmly integrated with the electric box 1 and the lead wire 9, and the adhesion of the sealant A is effectively prevented from being impaired due to vibration or aging. As a result, excellent waterproofness can be exhibited over a long period of time.

Of course, the present invention is not limited to the above-mentioned embodiment, and as in the second embodiment shown in FIG.
May be formed in a tubular shape with both upper ends reaching the printed circuit board 6, and the inside of the tube may be filled with a sealing agent. In this case, the entire periphery of the lead wire 9 in the electric box 1 is filled. The sealing agent A is used for sealing, and even a very small amount of water that enters through the gap between the bare wires inside the lead wires due to the capillary phenomenon can be sealed, and the waterproofness can be further improved.

[Effects] In short, since the present invention is constructed as described above, the lead wire is wired inside the box through the through hole formed in the electric box. The cylindrical through hole is formed by projecting the sealing agent into the retainer that is applied with a gap in the cylindrical through hole. It will be in a bite state. As a result, the adhesive performance of the sealant is improved, and the sealant is firmly integrated with the electric box and the lead wire, and the adhesion of the sealant is effectively prevented from being impaired due to vibration or aging. Therefore, it is possible to exhibit excellent waterproofness over a long period of time.

[Brief description of drawings]

The drawings show an embodiment of a waterproof sealing structure for an electric box according to the present invention. FIG. 1 is a sectional view of the electric box showing the first embodiment, and FIG. 2 is a second embodiment. It is sectional drawing of the electric box shown. In the figure, 1 is an electric box, 3a is a through hole, 5 is a structure,
6 is a printed circuit board, 9 is a lead wire, 10 is a retainer, A
Is a sealant.

Claims (1)

[Scope of utility model registration request] 1. A printed circuit board assembled to a structure is provided with a lead wire through a through hole of an electric box for incorporating the structure, wherein the through hole is bent so that its peripheral portion is inserted into the box. While being formed into a tubular shape, a tubular retainer having an inner cylindrical surface having a diameter larger than that of the tubular through hole is formed inside the electric box, and one end side of the retainer surrounds the cylindrical through hole with the inner cylindrical surface. It is arranged such that it is applied to the inner surface of the electric box and the other end is applied to the structure side, and further, the lead wire is passed through the retainer cylinder and a sealant is filled to seal it. A waterproof sealed structure for the electric box.