JP2015050809A - Electric connection box - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrical connection box of novel structure in which waterproofness of a wiring harness insertion port can be enhanced furthermore.SOLUTION: An electrical connection box 10 includes a case 14 housing an internal circuit, and a cylindrical wiring harness insertion port 72 penetrating the case 14, and through which a wiring harness 76 consisting of a wire bundle 88 connected with the internal circuit is inserted. At a part of the wiring harness 76 being inserted into the wiring harness insertion port 72, an elastic waterproof sheet 82 is wound around the outer periphery and brought into pressure contact with the inner surface 74 of the wiring harness insertion port 72. The elastic waterproof sheet 82 is composed of an independent foam or a semi-independent foam.

Description

  The present invention relates to an electrical connection box mounted on an automobile or the like, and more particularly to an electrical connection box provided with a wire harness insertion port for inserting a wire harness from the inside of the electrical connection box and taking it out to the outside.

  Conventionally, an electrical connection box mounted on an automobile has an internal circuit made up of electrical components such as fuses and relays and current-carrying members such as bus bars contained in the case. Many electric wires are connected to the member. A wire harness formed of a bundle of these electric wires is inserted through a cylindrical wire harness insertion port provided in the case of the electric connection box and taken out to the outside. For example, it is as described in JP 2010-136468 A (Patent Document 1).

  By the way, in such an electrical junction box, there exists a possibility that water etc. may permeate from the outside through a wire harness insertion opening. Therefore, for the purpose of preventing such water intrusion, as shown in FIG. 1 of Patent Document 1, an elastic waterproof sheet is wound around the outer periphery of the wire harness insertion portion through which the wire harness insertion port is inserted, and the wire harness and the wire are wound. A structure has been proposed in which an elastic waterproof sheet is sandwiched between the inner surface of the harness insertion opening. With this elastic waterproof sheet, a gap generated between the wire harness and the wire harness insertion port can be filled, and entry of water or the like from the outside through the wire harness insertion port can be advantageously prevented.

  However, since the elastic waterproof sheet in the conventional structure is made of urethane foam or the like, there is a possibility that intrusion of water or the like from the outside cannot be sufficiently prevented. That is, since urethane foam is a continuous foam, it has a large number of air bubbles inside, and the large number of air bubbles are connected to each other. In addition, since a small hole is opened in the thin film that separates the bubbles, water or the like may enter from the outside through the waterproof sheet.

  Further, in recent years, for the purpose of reducing the weight of a vehicle, there is a case in which a so-called aluminum electric wire whose core wire is made of an aluminum-based material is used instead of a so-called copper electric wire whose core wire is made of a copper-based material. It is increasing. When an aluminum electric wire is adopted, it is necessary to connect the aluminum electric wire to a copper terminal fitting made of a different metal. However, in the connection part where different metals with large standard electrode potential difference such as copper and aluminum are in contact with each other, when the contact part is exposed to water, the connection part is likely to be corroded (corrosion of the aluminum core wire). There has been a need to ensure waterproofness at the wire harness insertion port of the electrical junction box, as compared with the conventional case.

JP 2010-136468 A

  The present invention has been made in the background of the above-described circumstances, and its solution is to provide an electrical junction box having a novel structure capable of further improving the waterproofness of the wire harness insertion opening. It is in.

  According to a first aspect of the present invention, there is provided a case in which an internal circuit is accommodated, and a tubular wire harness that is inserted through the case and into which a wire harness composed of a bundle of electric wires connected to the internal circuit is inserted. An electrical connection box comprising an opening, and an elastic waterproof sheet is wound around the outer periphery of the wire harness insertion portion of the wire harness, and is pressed against the inner surface of the wire harness insertion port. In the invention, the elastic waterproof sheet is made of an independent foam or a semi-independent foam.

  According to this aspect, the elastic waterproof sheet is comprised by the independent foam or the semi-independent foam. Thereby, it is possible to advantageously prevent water from entering from the outside of the case through bubbles such as a continuous foam having a conventional structure. That is, in the closed cell foam, there are bubbles inside, but the bubbles are separated by a wall and are not connected, and water does not enter through the bubbles. On the other hand, in the state of the semi-independent foam as it is, the part where the bubbles are connected is also included like the continuous foam of the conventional structure, but the bubbles can be separated from each other by the wall by pressing, that is, compressing, Can prevent water from passing. Thereby, the improvement of the waterproofness of a wire harness insertion opening can be aimed at advantageously.

  According to a second aspect of the present invention, in the one described in the first aspect, at least a part of the electric wire bundle constituting the wire harness is constituted by an aluminum electric wire.

  According to this aspect, by using an independent foam or a semi-independent foam as the elastic waterproof sheet, the waterproofness of the wire harness insertion port is ensured as compared with the case of a continuous foam such as urethane foam having a conventional structure. Even when the wire harness is changed to a wire harness having a high waterproof requirement made of an aluminum electric wire, the waterproof property required for the electrical junction box can be advantageously ensured.

  According to the present invention, since the elastic waterproof sheet is composed of a closed foam or a semi-closed foam, it is possible to advantageously prevent water from entering from outside the case through bubbles such as a continuous foam having a conventional structure. Can do.

The disassembled perspective view of the electrical-connection box as one Embodiment of this invention. FIG. 2 is an exploded perspective view of a lower case and a slide cover of the electrical junction box shown in FIG. 1. III-III longitudinal cross-sectional enlarged view of FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, FIG. 1 and FIG. 2 show an electrical junction box 10 as an embodiment of the present invention. The electrical junction box 10 is configured to include a box body 12 that forms an internal circuit by arranging electrical parts, current-carrying members and the like (not shown), and an upper case 16 and a lower case 18 that constitute a case 14. Further, the lower case 18 is provided with substantially cylindrical wire harness insertion openings 72, 72 penetrating a peripheral wall 22c, which will be described later, of the lower case 18, and a corrugated externally attached to a wire harness 76 made up of an electric wire bundle 88 described later. A tube 78 is inserted through the wire harness insertion port 72 and taken out of the case 14. In the following description, unless otherwise specified, the upper direction is a vertical upper direction when the electric junction box 10 is assembled to the vehicle body, and is an upper direction and a lower direction in FIG. 1 where the upper case 16 is located. Means the vertically lower side in the assembled state and the lower side in FIG. 1 where the lower case 18 is located.

  The lower case 18 is integrally formed of, for example, a synthetic resin such as polypropylene (PP) or polyamide (PA) by injection molding or the like. As shown in FIGS. 1 and 2, the lower case 18 is integrally formed with peripheral walls 22 a to 22 d having a substantially rectangular frame shape extending upward from the outer peripheral edge of the bottom wall 20 and projecting upward. It is made into the box shape which has the opening part 24 in the box main body 12 side.

  On the outer surfaces of the peripheral walls 22a and 22c, a plurality of lock portions 28 (two in each of the peripheral walls 22a and 22c in this embodiment) projecting upward are formed. Further, on the outer surfaces of the peripheral walls 22a and 22c, a mounting leg portion 30 is formed so as to protrude outward from the lower case 18, and a bolt insertion hole 34 is provided through the mounting leg portion 30.

  As shown in FIG. 2, a large opening window 36 having a substantially rectangular shape in a front view is cut out on the peripheral wall 22 c between the lock portions 28, 28, and a slide cover 38 that covers the opening window 36 is attached. As a result, the lower case 18 is configured.

  A pair of guide rails 40, 40 projecting from the both side edges of the opening window 36 toward the inside of the opening window 36 are provided on the peripheral wall 22 c. The pair of guide rails 40 is provided over the entire length of each side edge of the opening window 36 (the entire length in the vertical direction in FIG. 2). Further, below the guide rail 40, lock claws 42, 42 projecting from a lock portion 62, which will be described later, provided on the slide cover 38 are projected.

  Further, a pair of first notches 46 are provided on the bottom edge 44 of the opening window 36. The pair of first notches 46, 46 are provided with a gap in the width direction of the opening window 36 (left and right direction in FIG. 2) with a gap therebetween, and are substantially convex downward at the bottom edge 44 of the opening window 36. A semicircular arc shape is opened and cut away. Positioning ribs 48 projecting upward from the bottom edge 44 of the opening window 36 are provided between the pair of first notches 46, 46. Further, the bottom edge portion 44 of the opening window 36 is provided with reinforcing ribs 50 and 50 that are disposed on the inner surface side of the peripheral wall 22c and integrally connected to the guide rails 40 and 40 and the positioning rib 48, respectively. ing.

  Further, on the outer surface of the peripheral wall 22c, thin plate-like inclined guide portions 52, 52 projecting obliquely upward toward the outside of the lower case 18 from the peripheral portions of the pair of first notches 46, 46 respectively protrude. It is installed.

  Thus, the slide cover 38 is attached to the opening window 36 provided in the peripheral wall 22c. The slide cover 38 has a substantially rectangular plate shape having an outer dimension slightly larger than the opening window 36, and guide rails 40, 40 provided on the opening window 36 are inserted into both side edges. Concave portions 54, 54 are provided.

  When the slide cover 38 is mounted, the lower end portion 56 of the slide cover 38 that contacts the bottom edge portion 44 of the opening window 36 has a pair of first notches 46 and 46 provided on the bottom edge portion 44. A pair of second notches 58, 58 are provided at opposing positions. The pair of second cutout portions 58 and 58 are provided with a gap in the width direction (left and right direction in FIG. 2) of the lower end portion 56 of the slide cover 38, and protrudes upward at the lower end portion 56 of the slide cover 38. An approximately semicircular arc shape is opened and cut out. A semi-ring-shaped protrusion 60 that is biased toward the outer surface of the slide cover 38 and protrudes toward the first notch 46 is provided on the end surfaces of the pair of second notches 58, 58 over the entire circumference. And projecting with a substantially constant wall thickness (see FIG. 2). Although not shown, a positioning recess is formed between the pair of second cutouts 58 and 58 to receive the positioning rib 48 provided on the bottom edge 44 of the opening window 36. Further, on the lower end portion 56 side of the slide cover 38, on both sides of the second cutout portions 58, 58, positions corresponding to the lock claws 42, 42 protruding from the peripheral wall 22 c, from the outer surface of the slide cover 38. A pair of lock portions 62, 62 projecting in the shape of a rectangular frame is provided.

  In the slide cover 38 having such a structure, the guide recesses 54 and 54 provided on both side edges are inserted into the guide rails 40 and 40 provided in the opening window 36 from the opening 24 side of the peripheral wall 22c, respectively. It is slid to the opening window 36 so as to be inserted. When the slide cover 38 is pushed below the opening window 36 and the lower end portion 56 of the slide cover 38 is brought close to the bottom edge portion 44 of the opening window 36, the slide cover 38 protrudes from the bottom edge portion 44 of the opening window 36. The positioning rib 48 is fitted into a positioning recess provided in the lower end portion 56 of the slide cover 38, and the positioning of the slide cover 38 with respect to the opening window 36 in the width direction is completed. Further, when the slide cover 38 is pushed downward, the lock portions 62 and 62 of the slide cover 38 come into contact with the lock claws 42 disposed below the guide rails 40 and elastically deform outward to lock the lock claws. Go over 42 and return to elasticity. As a result, as shown in FIGS. 1 and 2, in a state where the lock claw 42 is housed in the frame of the lock portion 62, the lock portion 62 and the lock claw 42 are engaged, and the slide cover 38 is opened. The window 36 is locked in a mounted state.

  The box body 12 is assembled to the lower case 18 via the upper case 16. First, the upper case 16 and the box main body 12 are engaged with a not-shown main body lock portion formed on the inner peripheral wall 64 of the upper case 16 and a lock claw 68 of the box main body 12 so that the box is accommodated in the upper case 16. The main body 12 is integrally assembled to the upper case 16. Next, the upper case 16 and the lower case 18 to which the box body 12 is assembled are assembled to the lower case 18 by engaging the lock claw 70 of the upper case 16 and the lock portion 28 of the lower case 18. As a result, the box body 12 assembled to the upper case 16 is accommodated in the peripheral walls 22 a to 22 d of the lower case 18. The box body 12 is covered with the upper case 16 from above and is covered with the lower case 18 from below, so that the electrical connection box 10 is formed.

  As described above, in the state in which the slide cover 38 is positioned and mounted on the opening window 36 and locked, the first cover provided on the bottom edge 44 of the opening window 36 is clear from FIGS. 1 and 2. A substantially cylindrical wire harness insertion port through which the notches 46 and 46 and second notches 58 and 58 provided at the lower end portion 56 of the slide cover 38 are connected to each other on the peripheral edge side and penetrates the peripheral wall 22c. 72, 72 are configured in a side-by-side manner in the circumferential direction of the peripheral wall 22c.

  On the other hand, as shown in FIGS. 1 and 2, an elastic waterproof sheet 82 is wound around the outer peripheral surface 80 of the corrugated tube 78 that is externally inserted into the wire harness 76. More specifically, an elastic waterproof sheet 82 is wound around the outer periphery of the corrugated tube 78 inserted into the wire harness 76 and inserted into the wire harness insertion port 72. The elastic waterproof sheet 82 may be attached to the corrugated tube 78 by using, for example, an adhesive or by fixing only both ends in the width direction of the elastic waterproof sheet 82 with a binding tape or the like. May be.

  As shown in FIG. 3, the elastic waterproof sheet wound around the outer periphery of the corrugated tube 78 in the wire harness insertion opening 72 configured by locking the slide cover 38 in the mounting state with respect to the opening window 36. 82 is held in pressure contact with the inner surface 74 of the wire harness insertion opening 72. Therefore, the elastic waterproof sheet 82 wound around the outer peripheral surface 80 of the corrugated tube 78 at the wire harness insertion port 72 has no gap between the outer peripheral surface 80 of the corrugated tube 78 and the inner surface 74 of the wire harness insertion port 72. It is designed to be filled. In addition, the protrusion 60 provided on the inner surface 74 of the wire harness insertion opening 72 is fitted into the valley portion 84 of the valley portion 84 and the mountain portion 86 constituting the outer peripheral surface 80 of the corrugated tube 78. Thus, the corrugated tube 78 is positioned and fixed with respect to the wire harness insertion opening 72.

  As shown in FIGS. 2 and 3, in the case 14, the extrapolated corrugated tube 78 is removed from the wire harness 76 composed of the wire bundle 88, and the wires 90 constituting the wire bundle 88 are removed. Are connected to an internal circuit (not shown) in the case 14. In the present embodiment, at least a part of each electric wire 90 constituting the electric wire bundle 88 is constituted by an aluminum electric wire. Here, for example, an aluminum electric wire is a core wire obtained by bundling a plurality of metal wires made of an aluminum-based material such as aluminum or an aluminum alloy, and covered with an insulating coating such as an ethylene-based resin or a styrene-based resin. It has a broken structure.

  The elastic waterproof sheet 82 of the present embodiment is made of an independent foam or a semi-independent foam. Note that urethane foam, which is an elastic waterproof sheet having a conventional structure, is composed of a continuous foam. Here, the closed foam and the semi-closed foam are mainly made of EPDM (ethylene-propylene-diene rubber). The independent foam is waterproof even if the bubbles formed in the rubber body are formed independently of each other. On the other hand, the semi-independent foam is composed of a part of the bubbles formed in the rubber body, so there are parts that lack waterproofness, but the bubbles are continuously formed by compression. Since it is crushed and filled with a rubber body, sufficient waterproofness can be secured by compression. In the case of a continuous foam, since almost all the bubbles are configured continuously for all the adjacent bubbles, even if compressed, it is difficult to prevent water from entering through the continuous bubbles, There was a limit to ensuring waterproofness. In particular, when an aluminum electric wire is used for the electric wire 90, a higher level of waterproofness of the wire harness insertion port 72 is required as compared with a conventional copper electric wire or the like. . In addition, as an independent foam, the 6800 series of the opt sealer by Nitto Denko Corporation etc. can be employ | adopted, for example. On the other hand, as the semi-independent foam, for example, Everlite Moran # 730 manufactured by Bridgestone Corporation may be employed.

  From the above, according to the electrical junction box 10 of the present embodiment, since the elastic waterproof sheet 82 is constituted by a closed foam or a semi-closed foam, a case through bubbles such as a continuous foam having a conventional structure. Intrusion of water from outside 14 can be advantageously prevented.

  Moreover, since the waterproof property of the wire harness insertion port 72 can be reliably improved in this way, even if the wire harness 76 is highly waterproof and is made of an aluminum electric wire as in this embodiment, the electrical connection The waterproof property required for the box 10 can be advantageously ensured.

  In addition, a protrusion 60 is formed in the wire harness insertion opening 72 over a substantially half circumference in the circumferential direction, and the protrusion 60 is fitted into the valley portion 84 of the corrugated tube 78 so as to be positioned and fixed. It has become. Therefore, the waterproofness of the wire harness insertion port 72 can be improved more reliably.

  As mentioned above, although embodiment of this invention was explained in full detail, this invention is not limited by the specific description. For example, in the above embodiment, the corrugated tube 78 is extrapolated to the wire harness 76, but the corrugated tube 78 may not be extrapolated. That is, the elastic waterproof sheet 82 may be directly wound around the wire harness 76.

  Further, it is sufficient that at least a part of each electric wire 90 constituting the electric wire bundle 88 is constituted by an aluminum electric wire, and all the electric wires 90 may be constituted by an aluminum electric wire.

10: Electrical junction box, 14: Case, 72: Wire harness insertion port, 74: Inner surface, 76: Wire harness, 82: Elastic waterproof sheet, 88: Wire bundle

Claims (2)

A case containing an internal circuit;
The case is provided with a cylindrical wire harness insertion port through which a wire harness composed of a bundle of wires connected to the internal circuit is inserted,
In the electrical connection box, the elastic waterproof sheet is wound around the outer periphery and attached to the insertion portion to the wire harness insertion port in the wire harness, and is in pressure contact with the inner surface of the wire harness insertion port.
The electrical junction box, wherein the elastic waterproof sheet is made of an independent foam or a semi-independent foam.   The electrical junction box according to claim 1, wherein at least a part of the wire bundle constituting the wire harness is constituted by an aluminum electric wire.

Images