JP4788010B2 - Waterproof structure for cable drawers of electronic equipment modules - Google Patents

Description

  The present invention relates to a waterproof structure used for a cable lead portion of an electronic device module that requires watertightness, such as an in-vehicle camera module.

  Conventionally, an electronic device module that requires watertightness, such as an in-vehicle camera module, is configured by incorporating various electronic circuit components and optical components in a watertight outer case. A cable for supplying power to an internal electronic circuit and exchanging signals is derived.

  Conventionally, a potting material has been used in order to ensure the water tightness of the cable lead-out portion in this main electronic device module (for example, Patent Document 1). This is because a space for filling the potting material is formed inside the outer case, and the cable is pulled out by filling the potting material into the potting material filling space in a state where the cable is pulled out through the outer case. The part is sealed.

JP 2009-265393 A

  In the conventional cable lead-out waterproof structure of the electronic device module as described above, when the cable is led out from the bottom surface of the potting material filling space, the cable is inserted into the cable through hole formed in the bottom surface of the space. Since the potting material is poured in the state of being penetrated, the potting material to be used is limited to a material having a viscosity that does not flow out from the gap between the cable and the cable through hole, and it takes time to fill the potting material. At the same time, there is a problem that it is difficult to sufficiently fill the details.

  Also, when filling the potting material, it is necessary to fix the mutual positional relationship between the outer case and the cable. The cable must be temporarily fixed with the cable inserted into the cable through hole, and then the potting material must be filled. In addition to the problem that the property is poor, there is a problem that if the temporary fixation is released too early, the part to which the potting material is attached is pulled out and the aesthetic appearance is impaired.

  Furthermore, when the cable is an FPC, there is a problem that the bending strength of the lead-out portion is low and there is a risk of disconnection.

  In view of such a conventional problem, the present invention can use a low-viscosity material for the potting material and has good workability, and the potting material leaks out and the potting material adhering portion is pulled out to impair the beauty. The purpose of the present invention is to provide a waterproof structure for a cable lead-out portion of an electronic device module that has no danger of disconnection of a drawn cable.

  The feature of the invention according to claim 1 that solves the conventional problems as described above and achieves the intended object is that a cable through hole is provided at the bottom of the outer case, and the cable is provided outside the outer case through the cable through hole. The outer case is provided with a potting material filling recess in which the cable through hole is opened on the bottom surface, and the potting material is filled in the potting material filling recess. In the waterproof structure for the cable lead-out portion of the electronic device module, an elastic bush made of a rubber-like elastic material into which the cable is inserted in a liquid-tight state is fitted into the cable through hole, and the cable is connected by the elastic bush and the cable. The potting material is filled in the potting material filling recess with the through hole sealed.

  The invention according to claim 2 is characterized in that, in addition to the configuration of claim 1, the elastic bush is formed in a cylindrical shape with a tapered outer peripheral surface, and the inner peripheral edge of the cable through hole is densely arranged on the outer periphery of the base end. An annular groove is formed so as to be fitted with the taper, and a tapered tip end side protrudes outside the bottom surface of the outer case.

  In the present invention, the cable through hole is fitted with an elastic bush made of a rubber-like elastic material into which the cable is inserted in a liquid-tight state, and the cable through hole is sealed by the elastic bush and the cable. When the potting material is filled in the upper potting material filling recess, when the hotting material is injected into the potting material filling recess, the cable through hole at the bottom of the recess is almost completely liquid. Even if a highly flowable potting material that can be closed tightly and has a low viscosity is used, this does not leak out from the cable through hole, and the appearance is not impaired. Since a high-fluidity potting material can be used, the filling property to the details is improved, and a high watertightness can be maintained.

  Also, when the potting material is filled, the cable is temporarily fixed by the elastic bush, and after the potting material is filled, the cable and the bush can be structured not to move relatively even with a slight external force even before complete solidification. Therefore, before the potting material is completely solidified, the process can proceed to the next step, and the workability is improved.

  Further, in the present invention, the elastic bushing is formed in a cylindrical shape having a tapered outer peripheral surface, and an annular concave groove in which the inner peripheral edge of the cable through hole is closely fitted is formed on the outer periphery of the base end portion, and the tapered tip is formed. By projecting the side out of the bottom surface of the outer case, the cable root is protected by the bush, and a local load is not applied to the base by bending, thereby eliminating the risk of disconnection.

It is a perspective view which shows the example which implemented this invention to the vehicle-mounted camera module. FIG.

  Next, an example in which the present invention is implemented in an in-vehicle camera module will be described with reference to FIGS.

  In the figure, reference numeral 1a is an outer case main body, and 1b is an outer case bottom lid for closing the bottom opening of the outer case main body 1a. Both the outer case main body 1a and the outer case bottom lid 1b are molded by a synthetic resin, and constitute the outer case 1 with these.

  A molded optical system holder 2 and a substrate holder 5 are accommodated in the outer case 1 in combination with each other.

  The optical system holder 2 is composed of a rectangular box-shaped substrate support part 2a having a downward opening, and a cylindrical lens unit fixing part 2b integrally provided at the center of the top part. One end of the lens unit 3 is screwed into the screw. Although not shown in detail in the drawing, the lens unit 3 has a structure in which a lens group is incorporated in the lens holding cylinder, and the end of the lens holding cylinder is screwed into the lens unit fixing portion 2b. Yes.

  The substrate supporting portion 2a has a substrate fixing step 4 formed on the inner peripheral surface thereof, and the image sensor holding substrate 6 is in contact with the substrate supporting portion 2a, and is fixed so as not to drop off by an adhesive. An image sensor 7 is mounted on the surface of the image sensor holding substrate 6 on the lens unit 3 side.

  The outer peripheral surface of the substrate holder 5 has a cylindrical shape that is the same shape as the outer peripheral surface of the substrate support portion of the optical system holder. By connecting the substrate holder 5 to the optical system holder 2, the optical system The substrate support part 2a of the part holder 2 is extended.

  On the inner peripheral surface of the substrate holder 5, a substrate fixing step 8 is formed at an intermediate position in the axial direction, and a circuit component holding substrate 9 is brought into contact therewith and fixed by an adhesive.

  In addition to the image sensor 7 on the surface of the substrate 6 described above, circuit components such as a DSP, a memory, and a preset circuit are mounted on the substrates 6 and 9. At the same time, a connector member and a cable connector 13 for connecting between the circuits of both the boards 6 and 9 are mounted, and a cable 14 leading out is connected.

  As shown in FIG. 2, this in-vehicle camera module is a substrate holder in which an optical system holder 2 holds a lens unit 3, holds an image sensor holding substrate 6, and holds a circuit component holding substrate 9. Watertightness is maintained by fitting the outer case bottom lid 1b with the cable 14 inserted into the outer case main body 1 and being electrically connected to the cable connector 13 being penetrated through the bottom surface in a state where 5 is connected. It can be assembled to the state.

  In the figure, reference numeral 15 denotes an O-ring for maintaining water tightness between the outer case main body 1a and the lens unit 3, and 16 denotes water tightness between the outer case main body 1a and the outer case bottom lid 1b. It is a gasket that maintains the properties.

  A potting material filling recess 20 is formed on the bottom surface of the outer case bottom lid 1b, and a cable through hole 21 is opened in the bottom surface of the potting material filling recess 20.

  An elastic bush 22 is fitted in the cable through hole 21 in a compressed state, and the cable 14 is inserted through the center thereof. The cable 14 is inserted through the center of the cable 14 while being elastically tightened by the elastic bushing 22, so that the liquid-tightness between the two is maintained.

  The elastic bush 22 is formed in a cylindrical shape with a tapered outer peripheral surface, and the cable 14 is inserted in a liquid-tight state in a through hole at the center thereof. An annular concave groove 23 is formed that is elastically fitted so that the periphery is maintained in a liquid-tight state, and the tapered tip end side 22a protrudes outside the bottom surface of the outer case bottom lid 1b.

  A lead wire 24 constituting the cable 14 is led out from the end of the cable 14 inside the case into the recess 20. The potting material 25 is filled in the potting material filling recess 20 so as to embed the lead wires 24. By filling the potting material 25, the cable lead portion of the outer case bottom lid 1b is completely sealed.

  The leading end of the lead wire 14 is drawn into the outer case bottom lid 1b and connected to the cable connector 13 at the leading end.

  The injection of the potting material 24 in the waterproof structure of the cable lead portion configured as described above is performed by fitting the bush 22 in which the cable 14 is inserted into the through hole in the center portion into the cable through hole 21, thereby 21 is temporarily closed, and the cable 14 is temporarily fixed to the outer case bottom lid 1b. In this state, the potting material 24 is injected into the potting material filling recess 20.

  At this time, since the cable through hole 21 is temporarily sealed by the elastic bush 22 and the cable 14, the injected potting material 24 does not leak downward even when a low-viscosity material is used. Also, since the cable 14 is temporarily fixed to the outer case bottom lid 1a via the elastic bushing 22, it can be easily pulled out even before the potting material 24 is solidified and filled. The next process work can proceed before the potting material 24 is sufficiently solidified.

DESCRIPTION OF SYMBOLS 1 External case 1a External case main body 1b External case bottom cover 2 Optical system holder 2a Substrate support part 2b Lens unit fixing | fixed part 3 Lens unit 4 Substrate fixing step 5 Substrate holder 6 Imaging element holding substrate 7 Imaging element 8 Substrate fixing Step part 9 Circuit component holding substrate 13 Cable connector 14 Cable 15 O-ring 16 Gasket 20 Recess for filling potting material 21 Cable through hole 22 Elastic bushing 22a Tapered tip side 23 Annular groove 24 Lead wire 25 Potting material

Claims (2)

A cable through hole is provided in the bottom of the outer case, and the cable is led out of the outer case through the cable through hole. The outer case includes a potting material filling recess having the cable through hole opened in the bottom surface, In the waterproof structure for the cable lead-out portion of the electronic device module in which the potting material is filled in the recessed portion for filling the potting material,
An elastic bush made of a rubber-like elastic material into which the cable is inserted in a liquid-tight state is fitted into the cable through hole, and the potting material is sealed with the cable through hole sealed by the elastic bush and the cable. A waterproof structure for a cable lead-out portion of an electronic device module, characterized in that a potting material is filled in a filling recess.   The elastic bush is formed in a cylindrical shape with a tapered outer peripheral surface, an annular groove is formed on the outer periphery of the base end portion, and the inner peripheral edge of the cable through hole is closely fitted, and the tapered distal end side is the bottom surface of the outer case. The waterproof structure for a cable lead-out portion of the electronic device module according to claim 1, which protrudes outward.

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